Document 5Dyw4kL8QK8K1G9n5XnkQnv30

RREEMMEEDDIIAALL IINNVVEESSTTIIGGAATTIIOONN RREEPPOORRTT PPHHAASSEE 22 FFLLUUOORROOCCHHEEMMIICCAALL ((FFCC)) DDAATTAA AASSSSEESSSSMMEENNTT RREEPPOORRTT FFOORR TTHHEE CCOOTTTTAAGGEE GGRROOVVEE,, MMNN SSIITTEE JJuunnee 22000077 PPrreeppaarreedd ffoorr 33MM CCoommppaannyy bbyy WesWWtEECShSeTTsOOteNNr,SSOPOeLLnUUnTTsIyIOOlNvNaSSn,,iaIINN1CC.9.380 West Chester, Pennsylvania 19380 WW..0O.. NNoo.. 0022118811..000022..003300..00000011 Exhibit 2162 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00000011 33MM_EENNVV_0000000033007777 I3MM_MMNNO011448833000022 VOLUME 1 OF 2 SSEECCTTIIOONN TABLE OOFF COONNTTENTS PPAAGGEE EXECUTIVE SUMMARY ........................................................................................ ES- 1 1. INTRODUCTION .............................................................................................. 1-1 1.1 SITE ASSESSMENT BACKGROUND ................................................. 1-1 1.2 REPORT ORGANIZATION ................................................................... 1-5 2. SITE SETTING .................................................................................................. 2-1 2.1 SITE LOCATION AND DESCRIPTION ............................................... 2-1 2.2 LAND USE AND DEMOGRAPHICS .................................................... 2-1 2.3 TOPOGRAPHY AND DRAINAGE ....................................................... 2-2 2.4 GEOLOGY .............................................................................................. 2-2 2.5 WATER USAGE AND HYDROGEOLOGY ......................................... 2-3 3. SUMMARY OF ACTIVITIES ......................................................................... 3-1 3.1 PHASE 1 FIELD ACTIVITIES ............................................................... 3-1 3.1.1 3.1.2 Results of the Phase 1 FC Assessment and Data Needs ........... 3-2 Phase 1 Recommendations ....................................................... 3-6 3.2 PHASE 2 FIELD PROCEDURES ........................................................... 3-6 3.2.1 3.2.2 3.2.3 Groundwater Monitoring Well Installation .............................. 3-7 Groundwater Sampling ............................................................. 3-8 Soil Boring and Soil Sampling Activities ................................. 3-8 3.3 ON-SITE AREAS SAMPLING .............................................................. 3-9 3.3.1 3.3.2 33.33.33 3.3.4 3.3.5 3.3.6 3.3.7 3.3.8 D1/D2 Area - Former HF Tar Neutralization Basin/Former Sludge Disposal Area ...................................... 3-10 D5 Area - Former Solids Burn Pit Area ................................ 3-11 DD99 AArrceaa -- FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiit.t.................................. 33--1122 Wastewater Treatment Plant Area ......................................... 3-13 Fire Training Area .................................................................. 3-13 Hydraulic Capture Zone Evaluation ...................................... 3-14 East and West Coves .............................................................. 3-16 Mississippi River ................................................................... 3-18 3.3.8.1 Porewater .......................................................... 3-19 3.3.8.2 Surface Water and Sediment ............................. 3-20 3.4 MPCA SPLIT SAMPLES ...................................................................... 3-22 44. RREESSUULLTTSS OOFF TTHHEE AASSSSEESSSSMMEENNTT c.o..o.v.v.c.v.v.s..n.r.s.s.n.s.s..s.s.s.s.s.s.s..s.m.i.s.s.s.s..s.s.i.s.s.s.s..s.s.s.s.s.s.s..s.s.s.s.s.s.s..s.s.i.n.s. $42-11 Z:\FOLDERS 0-9~,3m-coRage grove\Phase 2 FC Data Assessn~ent Report'~Final Pt~se 2 Repc~ doc i CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00000022 33MM_EENNVV_0000000033007788 3M MN01483003 SECTION SECTION 414.1 42 44.32 4.3 444.4 454.5 TTAABBLLEE OOFF CCOONNTTEENNTTSS ((CCoonnttiinnuueedd)) PPAAGGEE SUMMARY OF THE ANALYTICAL DATA QUALITY AND SUMMARY OF THE AN.ad~YTICAL DATA QUALITY AND DDAATTAA RREEDDUUCCTTIIOONN PPRROOCCEESSSS. ............................................................ 44--1l HYDROLOGICAL INTERPRETATION 43 HYDROLOGICAL INTERPRETATION ............................................... 4-3 ONSITEAREAS 4s ON-SITE AREAS ................................................................... 430 DUD2 Area Former HF Tar Neutralization 4.3.1 432 A4DBaIS3sL1iA2vneFsor-mFeorGsrrSomoleiurdnSdeovlaiDtdiessrpBosuanl PAirea aiiusss 4.3.2 433 44DY3322A1r2ea -- FoGsrromoleurnSdwuadtesrDisposalPi ipaess] 4.3.3 434 44Wa33s33te12water TGSroreloalutnSmduewnnatptlPeilrnagnStRaAemrspau.ll.i.tnsg Resuls aiLisoo 4.3.4 435 Fi44Ar333e454T112raining GSSAoorllrollcuaSSnuadnmwppalltiiennrggSRRaemespsulltitsnsg Results 1aaannn0 4.3.5 D1/D2 Area - Former I-IF Tar Neutralization Basin/Former Sludge Disposal Area ........................ 4.3.1.1 Groundwater ....................................... 4.3.1.2 Soil ...................................................... D5 Area - Former Solids Burn Pit ........................... 4.3.2.1 Groundwater ....................................... 4.3.2.2 Soil ...................................................... D9 Area - Former Sludge Disposal Pit .................... 4.3.3.1 Groundwater Sampling Results .......... 4.3.3.2 Soil Sampling Results ......................... Wastewater Treatment Plant Area ........................... 4.3.4.1 Groundwater Sampling Results .......... 4.3.4.2 Soil Sampling Results ......................... Fire Training Area .................................................... 4.3.5.1 Soil Sampling Results ......................... ............... 4-5 ............... 4-5 ............... 4-5 ............... 4-6 ............... 4-6 ............... 4-7 ............... 4-8 ............... 4-8 ............... 4-9 ............. 4-10 ............. 4-10 ............. 4-11 ............. 4-11 ............. 4-11 EAST AND WEST COVES ee 12 EAST _AND WEST COVES .................................................................. 4-12 441 EasCove 413 4.4.1 442 WS4S33e44444s11202i13322Cowe PSSSShuueeyrrddsffiiiiacmmccaeeeelmmWWCaaSShttaaaeemmrrrppsllSSciiaatnnmmrggppzllRRaiieiennsoggusnRRlseesssualltes a14S241i12607s00 4.4.2 East Cove ................................................................................ 4-13 4.4.1.1 Physical Characterization ................................... 4-13 4.4.1.2 Surface Water Sampling Results ....................... 4-16 4.4.1.3 Sediment Sampling Results ............................... 4-17 West Cove ............................................................................... 4-19 44.44.22.11 PPhhyyssiiccaall DDeessccrriippttiioonn .......................................... 44--1199 4.4.2.2 Surface Water Sampling Results ....................... 4-20 4.4.2.3 Sediment Sampling Results ............................... 4-20 MISSISSIPPI RIVER SAMPLING RESULTS a1 M1S SIS S1PP1 RIVER SAMPL1NG RESULTS .................................... 4-21 45.1 Porewater Locations a2 4.5.1 452 T4Sr55a11ne32at LocaSStueirdofinimsceentWaStaemrplSianmgplRiensguRlessuls 24i28s 4.5.2 453 4444Lo5555ng3232i1122tudinal SSSSLueeourddcafiiaacmmtcieeeeonnnttWWsaaSSttaaeemmrrppllSSiiaannmmggppllRRiieennsgguuRRlseesssuullttss i3a2a28s0 4.5.3 Porewater Locations ................................................................ 4-22 44.55..11.11 PPoorreewwaatteerr SSaammpplliinngg RReessuullttss .............................. 44-2222 4.5.1.2 Sediment Sampling Results ............................... 4-24 4.5.1.3 Surface Water Sampling Results ....................... 4-27 Transect Locations .................................................................. 4-28 4.5.2.1 Sediment Salnpling Results ............................... 4-28 4.5.2.2 Surface Water Sampling Results ....................... 4-28 Longitudinal Locations ........................................................... 4-29 4.5.3.1 Sediment Sampling Results ............................... 4-29 4.5.3.2 Surface Water Sampling Results ....................... 4-29 Z:~'OLDERS 0-9~3m-t oRage glOve~Pt~a~e 2 FC Data AssessinelR Repoll~F~tal Ptt~e 2 Repolt.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttssii 3MM_ENEVN_V0000000033007799 a3MW_MNNo0r1a4s83o0o0s4 22116622..00000033 SECTION TTAABBLLEE OOFF CCOONNTTEENNTTSS ((CCoonnttiinnuueedd)) PAGE o SUMMARY OF OBSERVATIONS ................................................................. 5-1 5.1 GROUNDWATER .................................................................................. 5- l 5.2 SOIL ......................................................................................................... 5-3 5.2.1 5.2.2 5.2.3 5.2.4 55.22..55 D 1/D2 Area Former I-IF Tar Neutralization Basin/Former Sludge Disposal Area ......................................... 5-3 D5 Area - Former Solids Burn Pit Area ................................... 5-4 D9 Area - Former Sludge Disposal Pit ..................................... 5-5 Wastewater Treatment Plant Area ............................................ 5-6 FiFriree TTrraaiinniinngg AArreeaa. ..................................................................... 55--66 5.3 EAST COVE ............................................................................................ 5-7 5.4 WEST COVE ........................................................................................... 5-8 5.5 MISSISSIPPI RIVER .............................................................................. 5-9 5.5.1 5.5.2 55.55.33 Porewater Sampling Locations (Porewater, Sediment and Surface Water) .......................................................................... 5-9 Transect Locations .................................................................. 5-11 LLoonnggiittuuddiinnaall LLooccaattiioonnss. ........................................................... 5S-1111 o DEVELOPMENT AND SCREENING OF RESPONSE ACTION ALTERNATIVE S .............................................................................................. 6-1 6.1 LIST OF POSSIBLE TECHNOLOGY TYPES ...................................... 6-1 REFERENCES ................................................................................................... 7-1 VOLLUUMME 2 OF 2 APPPEENNDDIICCES APPENDLX A-~HYDRAULIC CAPTURE ZONE EVALUATION APPENDLX B~BORING LOGS APPENDLX C--WELL EVACUATION/SAMPLING FOR~IS APPENDLX I)~FC ANALYTICAL DATA SUMMARY AND LABORATORY ANALYTICAL DATA PACKAGES Z:~'OLDERS 0-9~3m-t oRage glOve~Pt~a~e 2 FC Data AssessirtelR RepollkF~tal Ptt~e 2 Repolt.doc iii CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00000044 33MM_EENNVV_0000000033008800 3M MN01483005 TiTtitllee Figs Figure 22--11 LLIISSTT OOFF FFIIGGUURREESS PPaaggee SSiittee LLooccaattiioonn MMaapp. .................................................................................... 22-6 FFiigguurree 22--22 Figre23 Figure 2-3 Figure24 Figure 2-4 Figure 2:5 Figure 2-5 Figs 2 Figure 2-6 Figure 31 Figure 3-1 Figs 3.2 Figure 3-2 FFiigguurse 333-3 Figs 34. Figure 3-4 Figure 5 Figure 3-5 Figus 3 Figure 3-6 Figs 3.7 Figure 3-7 Figs 38 Figure 3-8 SSiittee LLaayyooutu.t ............................................................................................... 22-77 Generalized Sntgaphic Cross Section A-A" 25 Generalized Stratigraphic Cross Section A-A'. ....................................... 2-8 Cross Seon AA" Loaion 29 Cross Section A-A' Location ................................................................... 2-9 Bedrock Geoloe Map 210 Bedrock Geologic Map .......................................................................... 2-10 Groundwater Elevation Contour Map, Non-Fumping Condition, Groundwater Elevation Contour Map, Non-Pumping Conditions, Nay 2006 2m 8 May 2006 ............................................................................................ 2-11 Monitoring Wel and Soil Bving Locations - June 2006. sm Monitoring Well and Soil Boring Locations - June 2006 ..................... 3-23 Soil Sampling Locations - Fir Training Area sa Soil Sampling Locations - Fire Training Area ...................................... 3-24 Locationof ast and West Coves 325 Location of East and West Coves .......................................................... 3-25 Sampling Lot- WiesotConve 326 Sampling Locations - West Cove .......................................................... 3-26 Sampling Locations - Fas Cone sar Sampling Locations - East Cove ........................................................... 3-27 Porewater Sampling Locations sa Porewater Sampling Locations .............................................................. 3-28 Longitudinal Sampling Locations. 329 Longitudinal Sampling Locations .......................................................... 3-29 Transet Sampling Locrions 330 Transect Sampling Locations ................................................................. 3-30 FFiigguurree 44--11 FFiigguurree 424-2 Figure 43 Figure 4-3 GGrroouunnddwwaatteerr EElleevvaattiioonn CCoonnttoouurr MMaapp --- PPuummppiinngg CCoonnddititiioonnss,, $i 2006 a 3 May 2006 ............................................................................................ 4-31 Groundwater PBA, PFOA, and PFOS Concentrations a Groundwater PFBA, PFOA, and PFOS Concentrations........................ 4-32 Monitoring Well Insallaon Sil Samples PEBS, PFHS, PFOS Monitoring Well Installation Soil Samples PFBS, PFHS, PFOS und PFOA Concentrations PY and PFOA Concentrations ..................................................................... 4-33 FFiigguurree 44--44 Figure 4:5 Figure 4-5 DDS5 AArrceaa SSooiill BBoorriinngg PPFFBBSS,, PPFFHHSS,, PPFFOOSS,, aanndd PPFFOOAA Concentrations, June 2006 po Concentrations, June 2006 ..................................................................... 4-34 D9 Area Soil Boring PFS, PIS, PFOS and PFOA D9 Area Soil Boring PFBS, PFHS, PFOS and PFOA Concentrations. June 2006 43s Concentrations, June 2006 ..................................................................... 4-35 Z:\FOLDERS 0-9~,3m-cot~age grove\Ptmse 2 FC Data Assessznent Report\Final Pt~se 2 Repol~ doc CCoonfnifddeenntiiaall - 33MM IInnssuurraannccee DDooccuummeennttssiv 22116622..00000055 3MM_ENEVN_V0000000033008811 au_worassoos 3M MN01483006 Tite Title Figure 46 Figure 4-6 LLIISSTT OOFF FFIIGGUURREESS ((CCoonnttiinnuueedd)) PPaaggee Fire Training Area Soil EBA, PFHS, PEOS and PFOA Fire Training Area Soil PFBA, PFHS, PFOS and PFOA CCoonncecnetnrtraattiioonnss,, SSeepptteemmbbeerr 22000066 ........................................................... 44--3366 FFiigguurree 44--77 EEaasstt CCoovvee TTooppooggrraapphhyy aanndd SSuurrffaaccee WWaatteerr BBoouunnddaarryy ........................... 44-3377 Figure 5 Surface Water PFBA, PFOA and PROS Concentrations, Et Cove. 438 Figure 4-8 Surface Water PFBA, PFOA and PFOS Concentrations, East Cove .... 4-38 Figure 9 Sediment PFBA, PFOA and PFOS Concentrations, ast Cove... 439 Figure 4-9 Sediment PFBA, PFOA and PFOS Concentrations, East Cove ............ 4-39 Figus 10 West Cove Topography and Surface Wter Boundary. 0 Figure 4-10 West Cove Topography and Surface Water Boundary .......................... 4-40 Figure 4-11 Surface Water PBA, PFBA, PFOA, and PFOS Concentrations, Figure 4-11 Surface Water PFBA, PFBA, PFOA, and PFOS Concentrations, Westone pl West Cove .............................................................................................. 4-41 Figure 4-12 Sediment PHOS, PHBA, PFOA, and PEHS Consenrations, West Figure 4-12 Sediment PFOS, PFBA, PFOA, and PFHS Concentrations, West Ge wn Cove ....................................................................................................... 4-42 Figure 13 Porewater FOS Concentrations. a Figure 4-13 Porewater PFOS Concentrations......................................................... 4-43 Figure 4-14. Poewater PFOA Concenttions . aa Figure 4-14 Porewater PFOA Concentrations ......................................................... 4-44 Figure 4-15 Porewater PFBA Concenrations sas Figure 4-15 Porewater PFBA Concentrations ......................................................... 4-45 Figus 16 Sediment PROS Concenttions, 6 Figure 4-16 Sediment PFOS Concentrations ........................................................... 4-46 Figure 4-17 Sediment PFOA Concentrations. ar Figure 4-17 Sediment PFOA Concentrations .......................................................... 4-47 Figure 4-18 Sediment PFBA Concentrations a Figure 4-18 Sediment PFBA Concentrations .......................................................... 4-48 Figure 4-19. Surface Water PFOS Concentrations 0 Figure 4-19 Surface Water PFOS Concentrations .................................................. 4-49 Figure 420 Surface Water PFOA Concenttions 450 Figure 4-20 Surface Water PFOA Concentrations ................................................. 4-50 Figus 421 Surface Water PBA Concentrations as Figure 4-21 Surface Water PFBA Concentrations ................................................. 4-51 Figure 422 Transet Sampling Locations Sediment PBA, PFOA and PFOS Figure 4-22 Transect Sampling Locations - Sediment PFBA, PFOA and PFOS Concenirions as Concentrations ....................................................................................... 4-52 Figure 423 Transecr Sampling Locaion - Surface Water PBA, PFOA and Figure 4-23 Transect Sampling Location Surface Water PFBA, PFOA and PROS Concentons as PFOS Concentrati ons ............................................................................. 4-53 Figure 424. Longitudinal Sampling Location-s Sediment PBA, PFOA and Figure 4-24 Longitudinal Sampling Locations - Sediment PFBA, PFOA and PROS Concentrations ast PFOS Concentrations ............................................................................. 4-54 Z:~'OLDERS 0-9\3m-c ott age glOVe~Ptla~e 2 FC Data AssessinelR Repol*~F~tal Ptt~e 2 Repoi*.doc CCoonfnifddeennt{iiaall - 33MM IInnssuurraannccee DDooccuummeennttssv 22116622..00000066 3aMM_EENNVV_0000000033008822 a3Mu_wMoNr0a1s48s3o0o0r7 TTiittllee FFiigguurree 44--2255 LLIISSTT OOFF FFIIGGUURREESS ((CCoonnttiinnuueedd)) PPaaggee LPLooRnnOggiSittuCudodininncaealnltSSraaammtpiplolininnsgg LLooccaattiioonnss--SSuurrffaaccee W Waatteerr PPFFBBAA,PPFFOOAA aanndd ass PFOS Concentrations ............................................................................. 4-55 Z:~'OLDERS 0-9~3m-t oRage glOve~Pt~a~e 2 FC Data AssessinelR Repoll~F~tal Ptt~e 2 Repolt.doc CCoonfnifddeentni{aiall-- 33MM IInnssuurraannccee DDooccuummeennttssvi 22116622..00000077 33MM_EENNVV_0000000033008833 _3MMNMON1041E4383000088 TTititllee LIISST OF TABLES PPaaggee Table 3-1 Total Samples Collected - Phase 1 and Phase 2 .................................... 3-31 Table 3-2 Monitoring Well Construction Details ................................................... 3-32 Table 3-3 Groundwater Sampling Summary .......................................................... 3-33 Table 3-4 Samples Split with MPCA .................................................................... 3-34 Table 4-1 Summary of Aquifer Parameters ........................................................... 4-56 Table 4-2 Table 4-3 Groundwater PFBA, PFOA, PFBS, PFHS, and PFOS 2 - Concentrations - September 2006 ....................................................... 4-57 Soil Boring PFBS, PFHS, PFOS, and PFOA Concentrations - June 2006 ..................................................................................................... 4-58 Table 4-4 Fire Training Area Soil PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - September 2006 ....................................................... 4-61 Table 4-5 East Cove Surface Water PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - September 2006 ....................................................... 4-62 Table 4-6 East Cove Sediment PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations September 2006 ....................................................... 4-63 Table 4-7 West Cove Surface Water PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations September 2006 ....................................................... 4-64 Table 4-8 West Cove Sediment PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - September 2006 ....................................................... 4-65 Table 4-9 Porewater PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - September 2006 ................................................................................ 4-66 Table 4-10 Table 4-11 Mississippi River Sediment (Porewater Locations) PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - September 2006 ............... 4-67 i wo Mississippi River Surface Water (Porewater Locations) PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations September/October 2006 ....................................................................... 4-69 Z:\FOLDERS 0-9~,3m-coftage grove\Phase 2 FC Data Assessznent Report\Final Pt~se 2 Repc~ doc vii CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00000088 33MM_EENNVV_0000000033008844 3M MN01483009 - - LLIISSTT OOFF FFIIGGUURREESS ((CCoonnttiinnuueedd)) Title Page Table 4-12 TTaabbllee 44--1133 mwMississippi River Sediment (Longitudinal and Transect Locations) PFBA, PFOA, PFBS, PFHS, and PFOS Concentrations - October 2006 ........................................................................................................ 4-71 MMisisssiissssiippppii RRiivveerr SSuurrffaaccee W Waatteerr ((LLoonnggiittuuddiinnaall aanndd TTrraannsseecctt LLooccaattiioonnss)) PPFFBBAA,, PPFFOOAA,, PPFFBBSS,, PPFFHHSS,, aanndd PPFFOOSS CCoonncecnetnrtartaitioonnss. - October 2006 ....................................................................................... 4-72 Table 6-1 Initial Screening of Technology and Process Options - Soil .................. 6-4 Table 6-2 Initial Screening of Technologies and Process Options Groundwater ............................................................................................ 6-5 Table 6-3 Initial Screening of Technologies and Process Options - Sediment ........ 6-8 Z:~'OLDERS 0-9\3m-c ott age glOVe~Pt~a~e 2 FC Data AssessinelR Repol*~F~tal Ptt~e 2 Repoi*.doc viii CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00000099 33MM_EENNVV_0000000033008855 3M MN01483010 EESS.. EEXXEECCUUTTIIVVEE SSUUMMMMAARRYY The 3M Company (3M) Cottage Grove, Minnesota plant (Cottage Grove Site), formerly the 3M Chemolite plant, has been in operation since 1947. The facility currently manufactures a range of products which includes adhesive products, specialty paper, industrial polymers, abrasives, and reflective road sign materials. The facility also engages in research and development of a proprietary nature. In December 2004, 3M submitted to the Minnesota Pollution Control Agency (MPCA) the Facility-wide Fhlorochem~cal (FC) lnves#gatmn Work Plan (FC Work Plan) which was prepared by Weston Solutions, Inc. (WESTON) to voluntarily assess FCs at the Cottage Grove Site. In a letter to 3M dated January 31, 2005, MPCA approved the Work PPllaann wwiitthh mmoodidfiifcicaattiioonnss.. PPHHAASSEE 11 PPRROOGGRRAAMM DDuurriinngg 22000055,, 33MM iimmpplleemmeenntteedd tthhee FFCC ssiittee--rreellaatteedd aasssseessssmmeenntt pprrooggrraamm ((PPhhaassee 11 program) of the Cottage Grove Site in accordance with the MPCA approved FC Work Plan. 3M and WESTON presented the results of the assessment activities, data gaps, and recommendations for closing these data gaps to the MPCA and the Minnesota Department of Health (MDH) on March 22, 2006. Subsequently, on April 7, 2(306, 3M submitted the Fh~oroehemical (FC) Data Assessment Report (FC Data Assessment Report) to the MPCA. This document contained a summary of the assessment activities, the results of these activities, identification of data needs, and recommendations for the future course of action. PHASE 2 PROGRAM Based upon the agreements reached between 3M and MPCA during the March 22, 2006 meeting, 3M proceeded on a voluntary basis to initiate additional fieldwork as part of the PPhhaassee 22 FFCC AAsssseessssmmeenntt PPrrooggrraamm.. IInn aa lleetttteerr ttoo 33MM ddaatteedd JJuunnee 1133,, 22000066,, tthhee MMPPCCAA. indicated that the primary objective of the assessment (identifying the presence of gCs in various media) was met. The MPCA requested that 3M submit an addendum to the FC z :~F OLDI~S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--11 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033008866 3M MN01483011 22116622..00001100 Data Assessment Report containing a work plan to further define the extent of FCs at the facility. 3M submitted the Phase 2 FC Assessment Work Plan (Phase 2 Work Plan) on August 7, 2006 which incorporated MPCA comments. In accordance with the MPCA- aapppprroovveedd PPhhaassee 22 WWoorrkk PPllaann,, tthhee PPhhaassee 22 ffiieelldd wwoorrkk wwaass ccoommpplleetteedd iinn tthhee ffaallllooff 22000066 and included the following activities: Installation and sampling of eight groundwater monitoring wells in the vpplilcaaninnttit((yWWoWWfTtThPPe))Dpp1oo/nnDdd2ss., D9, and D5 Areas and the facility wastewater treatment Collection of soil samples during the drilling of the eight monitoring wells, 10 soil borings in the D5 and D9 Areas, and six band auger borings in the vicinity asooff tthhee FFiirree TTrraaiinniinngg AArreeaa.. Collection of sediment and surface water samples from the East and West Coves. Collection of sediment and surface water samples at 73 locations and porewwaatteerr ssaammpplles at 43 lloocatiioons ffrroomm tthhe MMisisssiissssiipppii RRiivveerr,, uuppssttrreeaammooff tthhee site and downstream to Lake Pepin. Performance of a hydraulic capture zone analysis based on the drawdown effects from the plant production wells, PW-5 and PW-6. CCOONNSSEENNTT OORRDDEERR In April 2007, 3M commenced discussions with the MPCA to formalize, under a Settlement Agreement and Consent Order (Consent Order), the process of conducting remedial investigations and response actions to address FCs at the site. The Consent OOrrddeerr bbeeccaammee eeffffeeccttiivvee oonn MMaayy 2222,, 22000077.. IItt rreeqquuiirreess tthhaatt 33MM ccoonndduucctt aa RReemmeeddiiaall Investigation/Feasibility Study (RI/FS) with respect to release or threatened release of FCs at and from the site. In the Consent Order, MPCA states "An RI Report addressing all of the investigative work required under the MPCA approved Phase 2 FC Assessment WWoorrkk PPllaann sshhaallll bbee ssuubbmmitittteedd ttoo MMPPCCAA bbyy JJuunnee 3300,, 22000077.. UUppoonn MMPPCCAA aapppprroovvaall ooff tthhee RI Report, the approved RI Report and the April 2006 Fluorochemical (FC) Data AAsssseessssmmeenmt RReeppoorrtt shhaallll be deeeemmed ttoo mmeeeett RRII RReeppoorrtt requiirreemmeenntts ...".". . AAccccoordrdiningglyly,, pending MPCA approval, this document is the Remedial Investigation Report, and Z:~FOLDI~.S.O-9'3m-cottage grove'Yhase 2 FC Data A~sessmmt RepolrWinal Phase 2 Report.doc or : EESS--22 CCoonfnifddeennttiiaall - 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00001111 33MM_EENNVV_0000000033008877 3M MN01483012 together with the April 2006 Ftuorochemical (FC) Data Assessment Report, meets the RI requirements for the Cottage Grove Site. It is further stated in the Consent Order that by June 30, 2007, 3M shall submit an FS work plan to address proposed response actions. The FS Work Plan is being submitted ccoonnccuurrrreennttllyy wwiitthh tthhiiss RRII rreeppoorrtt aass aa sseeppaarraattee ddooccuummenetn.t. SUMMARY OF OBSERVATIONS The following is an overview, by media and area, of the findings of the Cottage Grove Site Phase 1 and 2 FC assessments. This overview is presented to provide focus on areas ooffiinntteerreesstt tthhaatt wwiillll bbee ffuurrtthheerr eevvaalluuaatteedd aass ppaarrttooff tthhee FFSS pprroocceessss.. GGrroouunnddwwaatteerr In Phase l, PFOA and PFOS concentrations were detected in groundwater samples from monitoring wells MW-12 downgradient of the D5-Former Solids Burn Pit Area, MW-14 downgradient &the D8-Former Waste Disposal Area, and MW-101 downgradient of the DD1l-~Foorrmmeerr HHFF TTaarr NNeeuuttrraalliizzaattiioonn BBaassiinn aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 115500 ttoo 11,,886633 ppppbb. and from 80 to 324 ppb, respectively. It must be noted that PW-6 is downgradient of the D8 Area and is capturing the affected groundwater. The concentration of PFOA detected in production well PW-6 was 155 ppb. IInnPPhhaassee22,, tthhee ffoolllloowwiinngg wwaass ffoouunndd:: [19 Area - FCs were detected in groundwater at the D9 Area. PFBA was detected at concentrations ranging from 29.7 to 76.3 ppb. PFOA was detected aatt 2244..66 ppppbb iinn MMWW--110077bbuutt wwaass NNRR aatt MMWW--110055 aanndd MMWW-1-01066.. PPFFOOSS wwaass NNRil at all three monitoring wells in the D9 Area. Further analyses will be considered to quantify these results so that they may be used in the evaluation ooff aalltteerrnnaattiivveess iinn tthhee FFSS.. IInn PPhhaassee 11,, PPFFOOSS wwaass ddeetteecctteedd aatt mmoonniittoorriinngg wweellll MW-13 at a concentration of 16.5 ppb. This well is cross gradient to the D9 Area to the west. z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--33 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00001122 33MM_EENNVV_0000000033008888 3M MN01483013 Downgradient of D1/D2 Area~ WWTP Ponds, and D5 Area DDI1 AArreea PFOA was detected in Phase 1 wells MW-101 and MW-102 at concentrations of 150 ppb and 163 ppb, respectively. DD22AArreeaa PFOA was detected in MW-103 and MW-104 downgradient of the D2 Area at concentrations of 619 ppb and 414 ppb, respectively. PFBA was detected in MW-103 at 318 ppb and was NR at MW-104. PFOS was NR in both wells. WWTP Ponds Downgradient of the WWTP ponds, PFBA was detected in MW-108 at a concentration of 219 ppb. PFOA and PFOS ~vere NR at MW-108. D5 Area PPFFOOAA wwaass ddeetteecctteedd iinn PPhhaassee 11 wweellll MMWW--1122 aatt aa ccoonncceennttrraattiioonn ooff 11,,886633 ppppbb.. During Phase 2, PFOA was detected in MW-109 (shallow) and MW-110 (deep) at concentrations of 199 ppb and 136 ppb, respectively. Hydrological Interpretation - The area of groundwater capture induced by the pumping of two production wells (PW-5 and PW-6) was estimated by the interpretation of groundwater elevation data by constructing a groundwater elevation contour map. The proj ected width of capture extends east to MW-12 in the D5 Area, and west to a point midway between PW-5 and the West Cove. The analyses indicate that the pumping of PW-6 serves to capture grrooundwwaatteer ffrroomm tthhee DDS5 AArreeaa.. In addition to the hydrological evaluation, the laborato~ results for FC aannaallyysseess ooff ppoorreewwaatteerr ssaammpplleess ffrroomm tthhee MMisisssiissssiippppii RRiivveerr aallssoo ssuuppppoorrtt tthhiiss finding. FC concentrations detected in the porewater locations within the predicted zone of capture (IW-1 to IW-8) indicate concentrations of PFOS, PPFFOOAA aanndd PPFFBBAA aatt lleevveellss ssiiggnniiffiiccaannttllyy lleessss tthhaann tthhee ccoonncceennttrraattiioonnss ddeetteecctteedd in the D5 Area groundwater (MW-12, MW-109 and MW-110). For example, the maximum FC compound detected in groundwater at the D5 Area was PFOA (1,863 ppb at MW-12 in Phase 1), whereas PFOA was not detected in porewater samples collected frorn locations l~V-7 or IW-8, which are immediately downgradient of the D5 Area. Mississippi River porewater concentrations at locations outside of the projected zone of capture (IW-9 through lW-25) are higher than concentrations detected at locations IW-1 through IW-8 inside the predicted zone of capture. The hydrogeological and analytical data collected at the site support the conceptual site model which indicates that groundwater beneath the site flows ER towards and discharges to the Mississippi River. The capture zone created by z :~F C~LDI~.S .0-9' 3m-c ottage grove'l~lase 2 FC Data A~sessmmt RepoirWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttsEsS-4 33MM_EENNVV_0000000033008899 3M MN01483014 22116622..00001133 the pumping of PW-5 and PW-6 intercepts groundwater in the western part of tthhee ssiittee bbeeffoorree iitt ddiisscchhaarrggeess ttoo tthhee rriivveerr.. OOnn tthhee eeaasstteerrnn ppoorrttiioonn ooff tthhee ssiittee ((eeaasstt of the D5 Area) the groundwater flow is not intercepted and it discharges to the river. Soil D1/D2 Area - Former HF Tar Neutralization Basin/Former Sludge Disposal AArreeaa During Phase 1, in the D2 Former Sludge Disposal Area, FC concentrations up to 12,350 ppb PFOS were found in the sludge, which is located approximately 5 ft to 20 it bgs. Lower concentrations (ranging from 4.39 to 794 ppb PFOS) were detected in the uunnddeerrllyyiinngg nnaattiivvee ssooili.l wwhhiicchh bbeeggiinnss aatt aapppprrooxxiimmaatteellyy 2200 ttoo 2255 fftt bbegss.. In the D1 - Former HF Tar Neutralization Basin Area, FC concentrations up to 4,520 ppb PFOA were detected in the 5 to 30 ft bgs depth range in borings constructed just outside the suspected location of the basin structure and decreased below 30 ft bgs in the native soils (ranging from 53.9 to 375 ppb). Lower levels of PFOS and PFOA were detected at the deepest intel~'al sampled in the D 1 Area at 65 to70 ft bgs and in the D2 Area at 45 to 50 ft bgs. The depth to groundwater in this area is approximately 77 ft bgs. In Phase 2, Soil samples collected during the installation of monitoring wells MW-104 and MW-105, downgradient of the D2 Area, indicated PFOA and PFOS at significantly lower concentrations than samples collected from within the footprint of the D1 and D2 AArreeaass iinn PPhhaassee 11. . FFCCss wweerree ddeetteecctteedd uupp t1o0 6666..99 ppppbb ((PPFFOOSS aatt 000-.05.5 fftt bbegss)),. DD55 AArreeaa --- FFoorrmmeerr SSoolliiddss BBuurrnn PPiitt AArreeaa During Phase 1, in the D5 - Fonner Solids Burn Pit Area, concentrations of PFOS (up to 2,310 ppb) and PFOA (up to 1,375 ppb) were detected in soil samples to a depth of approximately 15 ft bgs in the one soil boring (SB D501) constructed in this area. Lower concentrations were detected at lower depths, below 15 feet (up to 46.8 ppb PFOS and up to 42.5 ppb PFOA). ER z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttsEsS-5 33MM_EENNVV_0000000033009900 3M MN01483015 22116622..00001144 In Phase 2, the following was found: The results of Phase 2 soil sampling in the D5 Area indicate that FCs were ddeetteecctteedd nneeaarr tthhee ssttoorrmmwwaatteerr rreetteennttiioonn bbaassiinn iinn tthhee ssoouutthhwweesstt ppoorrttiioonn ooff tthhee D5 Area and that higher levels are in a localized area (i.e., 1-2 boring locations). FC concentrations up to 2,650 ppb PFOS were detected in the 5-10 ft bgs sample interval at Phase 2 soil boring D5B02. The highest Phase 2 PFOA concentration for this area also was detected in this soil boring at 200 ppb in the 20-25 ft bgs interval, the deepest interval sampled. PFOS and PPFFOOAA aarree tthhee pprriimmaarryy FFCCss ddeetteecctteedd iinn tthhee DDS5 AArrceaa.. Samples from the remaining four Phase 2 soil borings also indicated ddeetteeccttiioonnss ooff PPFFOOSS ((99..2255 ttoo 339955 ppppbb)) aanndd PPFFOOAA ((00..558877 ttoo 114466 ppppbb)) bbuutt aatt lower concentrations than near the retention basin. The Phase 2 soil borings ((DD55BBO011 aanndd DD5SBB0033))iinnddiiccaatteedd lloowweerr ccoonncceennttrraattiioonnss ooff FFCCss Lthhaann PPhhaassee 11 ssooiill boring SB D501, which is in the same area. * BBaasseedd oonn tthhee PPhhaassee 22 ssooiill bboorriinngg llooggss ffrroomm ffiivvee ssooiill bboorriinnggss,, tthheerree wwaass nnoo definable soil horizons indicative of sludge, ash or other disposed material. * WWiitthh tthhee eexxcceeppttiioonnooff SSBB--DDS5BB0022,, FFCC ccoonncceennttrraattiioonnss ddeeccrreeaassee wwiitthh ddeepptthh aanndd are generally highest between 5 and 15 ft bgs. At SB-D5B02, PFOA was highest at the base of the boring (25 ft bgs) and PFOS was highest at the 5 to 1100 ffit bbggss iinntteerrvvaal.l. DD99 AArreeaa -- FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiitt --No investigation was conducted in this area in Phase 1. In Phase 2, the following was found: Soil samples collected from the northern and eastern parts of the D9 Area during the installation ofMW-106, MW-107, and soil borings SB-D9B01 and SB-D9B04 indicated FC concentrations up to 104,000 ppb PFOS (15-20 ft at MW-107). The soil boring logs indicated waste material was present and oorrggaanniicc vvaappoorrss wweerree rreeccoorrddeedd aatt tthheessee llooccaattiioonnss ttoo aa mmaaxxiimmuumm ddeepptthh ooff 2255 ffeeeett aatt SSBB--DDO9BBO011 aanndd 2211 ffeeeett aatt SSBB--DDBB0044.. TThhee mmaaxxiimmuumm ddeepptthh ssaammpplleedd wwaass the 20-25 ft bgs interval at each location. PFOS was detected in this depth interval with concentrations ranging from 1~060 ppb at SB-D9B04 to 57,000 ppb at MW-107. The soil boring logs indicated visible waste material was encountered at a maximum depth of approximately 30 ft bgs. Organic vapors were observed at 16 feet down to approximately 79 ft bgs in the MW-106 boring. Visible waste material and organic vapors were not observed at SB-D9B02 and SB-D9B03. Groundwater is present at an average depth of 85 feet which is well below the ddeepptthhooff tthhee eennccoouunntteerreedd wwaassttee mmataetreiraial.l. z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--66 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033009911 3M MN01483016 22116622..00001155 Wastewater Trostment Plant Area In Phase, theloving was found Wastewater Treatment Plant Area In Phase 2, the following was found: + Sil amples collected during roitorng well MVW-108 ngallaion ited Noil samples collected during monitoring well MW-108 installation indicated oncom of PE0S angie om 155 pb 3025 by 030 po 15 concentrations of PFOS ranging from 12.5 ppb (20-25 ft bgs)to 230 ppb (0.5Rwy Th PFOS contention sol ot ATW-I0R here wo dep 5 ft bgs). The PFOS concentrations in soil at MW-108 decrease with depth. Detd PFO cancmron rigs Hom 3.02 i (0051 by 0 6350 Detected PFOA concentrations range from 3.02 ppb (0-0.5ft bgs) to 63.3 ppb ((55--1100 fftt bbggss)).. FFiirree TTrraaiinniinngg AArreeaa TheFiTed for ing ad octae i da. cotctor omg a. The FTA is used for fire training and an adjacent area is used as a contractor storage area. In Phase 1 at he Fie Tring Ars, PROS wa dette a cocenatons fo 1A20 In Phase 1, at the Fire Training Area~ PFOS was detected at concentrations up to 1,820 ob primary in sallow sis to 3 dep of A bes, with significant ower ppb primarily in shallow soils to a depth of 5 ft bgs, with significantly lower concenaons dotted at owe eh. concentrations detected at lower depths. In Phase 2, the following was found: = SSooiill ssaammpplleess wweerree ccoolllleecctteedd ffrroomm ssiixx hhaanndd aauuggeerr llooccaattiioonnss.. OOff tthhee 1122 FFCC ey mn compounds analyzed, the primary FCs detected in the Phase 2 program were PPFFOOSS aanndd PPFFOOAA.. TThhee rreessuullttss ooff tthhee PPhhaassee 22 ssaammpplliinngg pprrooggrraammss iinnddiiccaattee tthhaatt PEO so alo oon FEA 51 yw omen e830 PFOS was detected at location FTA06 (2-3 It) with a concentration of 2,948 Tis samen oe hom rage ee sets of he od ppb. This sample was collected from a drainage swale south of the lined Din pont arto cold om ber rae ts sr te nc holding pond. Samples collected from other drainage swales near the lined olin pond (-TA0s nd FTAOS) cad PROS concmentons raring frhfrooolmmdin44g5588pppoppnbbd (((FFFTTTAAAO0S05,4, 00a--n11df1t)F) TttooA110,,500)2266inppdppibbca((tFeFdTTAAP00F44O,,0S0--11coffttn)).c. entrations ranging + PROS was sso dered from a sample (FTA coll ut off of2 PFOS was also detected from a sample (FTA09) collected just off of a Cortepl for os iin. ocr of31 po wos de concrete pad used for fire training. A concentration of 747 ppb was detected in COT ample A deer sani cdo be Shand ih s ho oer the 0-1 ft sample. A deeper sample could not be obtained with a hand auger et nd hoe crocs due to large gravel that was encountered. The C elt fom the FTA sampling nite tht The FC results from the FTA sampling indicate that: HHiigghheerr FFCC ccoonncceennttrraattiioonnss aarree ttyyppiiccaallllyy ffoouunndd iinn llooccaalliizzeedd aarreeaassooffddrraaiinnaaggee + Th ihe concenons re cl nd i esl andsui soi The higher concentrations are typically found in the shallow and surficial soils + Adon of soils and car disurbancs round the nw soma bi Addition of soils and earth disturbance around the new stormwater basin ((dduurriinngg ccoonnssttrruuccttiioonn)) hhaass rreessuulltteedd iinn lloowweerr ccoonncceennttrraattiioonnss CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss rr . EESS--77 z:~FC~LDI~.S.0-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 22116622..00001166 33MM_EENNVV_0000000033009922 swnnn 3M MN01483017 EAST COVE Based on the physical characterization and the analytical results from the Phase 1 and PPhhaassee 22 FFCC aasssseessssmmeennttss conndduucctted inn tthhe ttwwo acre EEaasstt CCoovvee,, tthhe ffoolllloowwiinng keyy observations can be made: Surface Water There is a continuous flow- of water through the cove due to the Cottage Grove plant cooling water and WWTP discharge, stormwater discharge from the ppllaanntt aanndd rruunn--ooffff ffrroomm tthhee ccoovvee ddrraaiinnaaggee aarreeaadduurriinngg ssttoorrmm eevveenntsts.. No significant differences in FC concentrations were detected between the Phase 2 surface water samples collected at the East Cove inlet and outlet locations. Sediment Of the 4 FC compounds analyzed during the Phase 1 assessment and the 12 FC compounds analyzed during the Phase 2 assessment, the highest concentrations detected in sediment from the East Cove were PFOS and PFOA. + AAtotottaalloofftthhrreeee ddiissttiinncctt llaayyeerrss wweerree oobbsseerrvveedd iinn sseeddiimmeenntt ccoorreess ccoolllleecctteedd ffrroomm the East Cove as observed in 7 probe locations in the lower part of the cove. These layers consisted of a firm top fine granular layer, and middle semi-solid fine silt layer (where a black residue layer was encountered), and a bottom sandy clay layer. The middle layer observed ranged from 2 inches to 2 feet in tthhiicckknneessss,, aappppeeaarriinngg t1o0 eexxiisstt iinn ppoocckkeettss tthhrroouugghhoouutt tthhee lloowweerr ppaarrtt ooff EEaasstt Cove. This black residue layer was encountered at depths of 1.0 to 2.5 feet below the top of the sediment. The highest concentrations of PFOS and PFBA (65,450 ppb and 94.6 ppb, respectively) were detected in the middle sediment layer where black residue wwaass oobbsseerrvveedd.. TThhee hhiigghheesstt ccoonncceennttrraattiioonn ooff PPFFOOAA 11.,884455 ppppbb wwaass ddeetteecctteedd iinn the bottom sediment layer. `WWEESSTT CCOOVVEE TThhee WWeesstt CCoovvee iiss aapppprrooxxiimmaatteellyy oonnee aaccrree iinn ssiizzee.. IItt rreecceeiivveess ssuurrffaaccee ddrraaiinnaaggee ffrroomm tthhee Cottage Grove Site Contractor Storage Yard and the Fire Training Area from the northeast and from the area around the Eagle Point municipal sewage treatment plant (STP) to the west. The STP outall discharges directly to the Mississippi River and does z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--88 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00001177 33MM_EENNVV_0000000033009933 3M MN01483018 not enter the West Cove. The water in the West Cove is generally stagnant and flow velocities were not measurable. Surface Water * + man Sediment SSuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess ccoolllleecctteedd dduurriinngg PPhhaassee 11 aanndd PPhhaassee 22 sampling programs indicate the detection of very low concentrations of FCs, primarily PFOA and PFOS. PPFFOOSS wwaass ddeetteecctteedd aatt aa ccoonncceennttrraattiioonn ooff 11..77 ppppbb ((00..55 f1t)) aatt tthhee PPhhaassee 22 upstream surt'ace water sample location (WC-4). PFOS was also detected at a ssiimmiillaarr ccoonncceennttrraattiioonn ((11..2277 ppppbb)) iinn tthhee uuppssttrreeaamm PPhhaassee 1| ssuurrffaaccee wwaatteerr ssaammppllee (WC-1). = PPFFOOSS ccoonncceennttrraattiioonnss iinn tthhee sseeddiimmeenntt ssaammpplleess rraannggeedd ffrroomm 1155..22 ppppbb ((PPhhaassee 11,, WC-3) to 137 ppb (Phase 2, WC-07). PFOA was also detected in sediment samples ranging from 11.2 ppb (WC-06, 0-6 in) to 15.9 ppb (WC-07, 0-6 in). No sludge/waste material or discolored sediment was encountered in West Cove sediments. MISSISSIPPI RIVER PPoorrewwaatteerr SSammpplliinngg LLooccaattiioonnss ((PPoorrewwaatteerr,, SSeddiimmeenntt anndd SSuurrffaaccee WWaatteerr)) IInn PPhhaassee 22,, ssaammpplleess ooff ppoorreewwaatteerr,, sseeddiimmeenntt aanndd ssuurrffaaccee wwaatteerr wweerree ccoolllleecctteedd aatt 4433 locations along the shoreline of the river. The higher concentrations of FCs were detected at three general areas t~or each of the media sampled: IW-22 to lW-25 along the eastern portion of the shoreline near the East Cove (approximately 1,000 feet) IW-19 transect along the eastern shore near the D1/D2/D9 Areas IW-14 transect near the WWTP area Eastern Portion of the Shoreline Near the East Cove area, concentrations of PFOS, PFOA and PFBA were detected in both porewater (up to 206 ppb, 758 ppb and 157 ppb, respectively) and sediment samples (up to 168 ppb, 130 ppb and 53.4 ppb, respectively). In surface water, PFOS concentrations at IW-22 to IW-25 range froln 0.0945 to 0.539 ppb. PFOA concentrations range from 0.141 ppb to 0.611 ppb. For z :~F C~LDI~S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or EESS--99 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00001188 33MM_EENNVV_0000000033009944 3M MN01483019 PFBA, 5 of the 8 samples were NR. Concentrations in the remaining three ssaammpplleess rraannged ffrroomm 11.6 .1p6pppbb ttoo 6..992 ppppbb.. TTrraannsseeccttss The detection of FC concentrations in porewater and sediment samples correlate closely and in general decrease with increasing distances from the shoreline (southerly) at the transect locations (1W-19, IW-14 and IW-9). One exception is at 1W-19f where porewater concentrations of PFBA decrease bffreroyommondsshhoIoWrree)-)19t(o0d a(a30cc0oonnfccteenfnrtotrrmaattiisoohnnorooef)f (11111.4880pppppbpb.b.) SSaenedddiimmineecnnrtet asssaeammapptllIeeWss -ff1rro9omfm(5tt0hh0eessfeet locations also exhibit a similar trend. The highest PFOS concentration detected in surface water was from location I1WW--1133.. OOtthheerr llooccatiioonns wwhheerre FFCCss aarree ddeettected aatt hhiigheerr ccoonncceennttrraattiioons iinn porewater and sediment are IW-ll, IW-13 and IW-9a. These locations are east of D5 and west of the WWTP pond area. At the locations near the West Cove and Fire Training area (IW-1 to IW-7), PFOA and PFOS are the only FC analytes detected in sediment. PFOS was detected at each location and PFOA was detected at IW-3, 1W-5 and IW-6. In the porewater samples, PFOS was detected only at lW-1, IW-2 and IW-3. PFOA was detected at lW-1 to IW-6 and not detected at IW-7. Concentrations ooff FFCCss iinn tthhiiss aarreeaa ((IIWW--11 ttoo IIWW--77)) wweerree ssiiggnniiffiiccaannttllyy lloowweerr tthhaann tthhee ceaasstetren part of the shoreline. * TThhee FFCC ccoonncceennttrraattiioonns ddeetteecctteedd iinn ppoorreewwaatteerr,, sseeddiimmeenntt aanndd ssuurrffaaccee wwaatteerr iinn the shoreline area within the zone of capture of production wells PW-6 and PW-5 are either not detected or very low. This indicates that FC concentrations in site groundwater are being captured in the area of PW-5 and PW-6 before they reach the river. Transect Locations Sediment and surface water samples were collected from the 3 transects (13 total sampling locations) across the Mississippi River. Also, water samples were collected at the water surface at the five locations along Transect XS-02. Sediment - The river transect results indicate that PFOS was the only FC compound of tthhee 1122anaanlaylytteess ddeetteecctteedd iinn sseeddiimmeenntt aatt aa mmaaxxiimmuumm ccoonncceennttrraattiioonn ooff 22..6666 ppppbb ((XXSS--22a)a.). Surface Water - Surface water sampling results indicate that PFOS was not detected in any of the samples. PFOA was detected in only three samples at a maximum Z:~FQLDI~.S.O-9'3m-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--1100 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00019 33MM_EENNVV_0000000033009955 3M MN01483020 concentration of 0.199 ppb (XS-02e). PFBA was not detected in 23 of 30 samples collected at the 13 locations. NRs were reported for the remaining 7 samples. Longitudinal Locations SSeeddiimmeenntt aanndd ssuurrffaaccee wwaatteerr ssaammpplleess wweerree ccoolllleecctteedd ffrroomm 1177 llooccaattiioonnss aalloonngg approximately 40 miles of the Mississippi River tom five miles upstream of the Cottage Grove Site and downstream to Lake Pepin. Sediment - The results indicate that only PFOS and PFOA were detected in sediment samples. PFOA was only detected in the samples at the head of Lake Pepin with ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..444411 ppppbb ttoo 11..0099 ppppbb.. PPFFOOSS wwaass ddeetteecctteedd wwiitthh concentrations ranging from 0.142 ppb to 3.16 ppb in 17 of the 26 samples collected. PFBA was ND in 22 of the 26 samples and NR in the remaining four samples. Surface Water - PFBA and PFOA were the only FCs detected in the longitudinal surface water samples and these concentrations were very low. PFBA was detected in 5 of the 17 samples with concentrations ranging from 0.0530 ppb to 0.0790 ppb. l'he other 12 samples were all ND. PFOA was detected in three samples with concentrations ranging ffrroomm 00..00550088 ppppbb ttoo 00..00775511 ppppbb.. TThhee ootthheerr 1133 ssaammpplleess wweerree NNDD aanndd oonnee ssaammppllee wwaass NNRR.. PFBS, PFHS, and PFOS were either ND or NR. DEVELOPMENT AND SCREENING OF RESPONSE ACTION ALTERNATIVES In accordance with the requirements of the Consent Order Section VI and Exhibit A, SSeeccttiioonn IIIIIL.EE.33,, tthhee ddeevveellooppmmeenntt aanndd ssccrreeeenniinngg ooffrreessppoonnssee aaccttiioonn aalltteermnaattiivveess ffoorr tthhee SSiittee will be based on the List of Possible Technology Types, presented in the RI Report and FS Work Plan and approved by the MPCA Commissioner. General response actions have been identified for the Cottage Grove Site based on the information and data provided in this RI. General response actions, response technology ttyyppee,, aanndd aassssoocciiaatteedd pprroocceessss ooppttiioonnss wweerree ssccrreeeenneedd ffoorr ffuurrtthheerr eevvaalluuaattiioonn oonn tthhee bbaassiiss ooff technical implementability. The general response action/technology types and process z :kF OLDI~.S .0-9' 3m-c ottage grove'l~nase 2 FC Data A~sessmmt RepoirWinal Phase 2 Report.dec or : EESS--1111 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00002200 33MM_EENNVV_0000000033009966 3M MN01483021 options that have been retained as the List of Possible Technology Types from this initial screening are summarized below: LLIISSTT OOFF PPOOSSSSIIBBLLEE TTEECCHHNNOOLLOOGGYY TTYYPPEESS SSaoiill Removal - Excavation Treatment - Thermal Incineration Disposal - Landfill - New landfill - Existing landfill Containment - Cap - Soil/clay cap - Engineered multilayer cap Institutional and Site Controls - Access restrictions - Deed restrictions - Fencing No action Groundwater Collection - Groundwater recovery Recovery wells Discharge - On-site + CCoonnttaaiinnmmeenntt --- CCaapp Soil/clay cap Engineered multilayer cap Treatment - Physical - Activated carbon - Ion exchange resin - Reverse osmosis - Air stripping Institutional and Site Controls - Deed restrictions - Fencing - Monitoring No action z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : EESS--1122 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00002211 33MM_EENNVV_0000000033009977 3M MN01483022 Sediment tnt ms Removal - Excavation/Dredging Treatment - Physical - Dewatering - Surface water diversion Treatment - Thermal Incineration Disposal - Landfill - New landfill - Existing landfill Containment - In Situ Cap Clean sediment, sand, gravel, geotextile, or liner Institutional and Site Controls - Access restrictions - Deed restrictions - Fencing No action UUppoonn aapppprroovvaall ooff tthhee RRII RReeppoorrtt aanndd FFSS WWoorrkk PPllaann bbyy MMPPCCAA,, tthheessee tteecchhnnoollooggyy ttyyppeess aanndd associated process options will be assembled into response action alternatives for screening and further evaluation. The FS Work Plan, which provides a description of the response alternative development, screening, and evaluation process, is being submitted concurrently with this RI Report. Z :~F OLDI~S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnNlt RepolrWinal Phase 2 Report.doc or : EESS--1133 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..000022 33MM_EENNVV_0000000033009988 3M MN01483023 11.. IINNTTRROODDUUCCTTIIOONN 11..11 SSIITTEE AASSSSEESSSSMMEENNTT BBAACCKKGGRROOUUNNDD TThhee 33MM CCoommppaannyy ((33MM)) CCoottttaaggee GGrroovvee,, MMiinnnneessoottaa ppllaanntt ((CCoottttaaggee GGrroovvee SSiitte),), ffoorrmmeerrllyy tthhee 33MM CChheemmoloilittee ppllaanntt,, hhaass bbeeeenn iinn ooppeerraattiioonn ssiinnccee 11994477.. TThhee ffaacciilliittyy ccuurrrreennttllyy mmaannuuffaaccttuurreess aa rraannggee ooff pprroodduuccttss wwhhiicchh iinncclluuddeess aaddhheessiivvee pprroodduuccttss,, sSppeecciiaalltyy ppaappeer,, engages in research and development ofa proprietary nature iinndduussttrriiaall ppoollyymmeerrss,, aabbrraassiivveess,, aanndd rreefflleeccttiivvee rrooaadd ssiiggnn mmaateteririaallss.. TThhee ffaacciilliittyy aallssoo engages in research and development of a proprietary nature. In December 2004, 31 submited to the Minnesota Pollution Control Agency (PCA) ItnheDFeacceimlibye-rvi2d0e04F,lu3oMrocsuhbemmiicttaeld (tFoC)theInM vesintingeastoitoan PWoollruktioPnlaCn o(nFtrColWoArgkenPclyan()MwPhCiAch) twhaesFparceipliatrye-wd idbye FWehstotroonchSeomluitciaolns(,F(I~nc.l~v(eWstEigSaTtiOonN)WotorkvPolluannta(rFiCly WasosrekssPlFaCns) wa hitchhe wCoatstapgreepGarroedvebySitWe eTsthoen WSoorluktioPnlas,n Ipnrce.se(nWteEdSaTOsNyste)mtaotivcoalupnptraorsilcyh atsosecsosllFecCtsdaattthien Cvaortitoaugse eGnvroivroenmSeitnet.alThmeedWiaorkrelPaltaend ptoreFseCntmeadnuafascytsuterminagticopaerpaptriooansc.h tIon a eter to 3M collect data in vdaatrieoduJsaneunavriryo3n1m, e2n0t0a5l,mMePdiCaArealaptperdovteodFtChemWaonrukfaPcltaunrinwigthopmeodraitfiiocnast.ioInns.a letter to 3M dated January 31, 2005, MPCA approved the Work Plan with modifications. Dung 2005, 3M implemented the FC ste-elaed assessment program (Phase 1 During 2005, 3M implemented the FC site-related assessment program (Phase 1 pprrooggrraamm)) aatt tthhee CCoottttaaggee GGrroovvee SSiittee iinn aaccccoorrddaannccee wwiitthh tthhee MMPPCCAA-a-apppprroovveedd FFCC WWoorrkk PPllaann.. DDuurriinngg tthhee ccoouurrssee oofftthhee FFCC aasssseessssmmeenntt pprrooggrraamm,, ddaattaa omfrom tthhee ssaammpplleess ccoolllleecctteedd dduurriinngg PPhhaassee 1| wweerree ssuubbmmitittteedd 0to tthhee MMPPCCAA iinn iinntteerriimm pprrooggrreessss rreeppoorrttss aanndd aaddddeennddaa.. 33MM aanndd WWEESSTTOONN pprreesseenntteedd tthhee rreessuullttss ooff tthhee aasssseessssmmeenntt aaccttiivviittiieess,, ddaattaa ggaappss,, aanndd rreeccoommmmeennddaattiioonnss ffoorr cclloossiinngg tthheessee ddaattaa ggaappss ttoo tthhee MMPPCCAA aanndd tthhee MMiinnnneessoottaa DepartofmHeeanltth (MDH) on March 22, 2006. Subsequently, on Api 7, 2006, 3M Dsuebpmairtttmedentthoef HHleuaoltrhoc(hMemDiHca)lon(HMC)arcDhat2a2, A2s0s0e6s.smSeunbtseRqeupeonrttly,(oFnC ADpatrial. 7A, s2s1e30s6s,me3nMt Rsuepbomrtit)tedto tthhee MFPlCuoAr.ocThheimsicdaolcu(m1e%n)t DcoanttaaiAnesdseasssmuemnmtarRyeopfotrthe(FaCsseDsastmaenAt sascetsisvmiteesn,t Rtheeporerst)ulttos tohfetMhePsCe Aac.tiTvhitisesd,oicduemnteinfitccatoinotnaoinfeddaatasunmeemdasryanodf rtheecoamsmseesnsdmateinotnasctfiovititehse, the results of these activities, identification of data needs and recommendations for the ffuuttuurree ccoouurrssee ooff aaccttiioonn.. BBaasseedd uuppoonn tthhee aaggrreeeemmeennttss rreeaacchheedd bbeettwweeeenn 33MM aanndd MMPPCCAA dduurriinngg tthhee MMaarrcchh 2222,, 22000066 mmeeeettiinngg,, 33MM pprroocceeeeddeedd oonn aa vvoolluunnttaarryy bbaassiiss 0to iinniittiiaattee aaddddiittiioonnaall fer fieldwork aass ptpart ooftf thhee PPhhaassee 22 FFCC AAsssseessssmmeenntt PPrrooggrraamm.. SSppeeccififiiccaallllyy,, 33MM hhaadd pprrooppoosseedd iinnssttaallllaattiioonn ooff er z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc Y CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummenetnsts.1-1 33MM_EENNVV_0000000033009999 W3M_MNMONT04184833002244 22116622..00002233 aaddddiittiioonnaall bboorriinnggss aanndd ggrroouunnddwwaatteerr mmoonnititoorriinngg wweellllss aarroouunndd tthhee DDI1//DD22,, DDS5,, aanndd DD99 AArreeaass.. TThhee MMPPCCAA ggaavvee pprreelliimmiinnaarryy aapppprroovvaall ffoorr tthheessee bboorriinnggss aanndd wweellllss oonn MMaayy 1177,, 22000066 aanndd ddiissccuusssseedd tthhee ssaammpplliinngg aapppprrooaacchh wwiitthh 33MM aanndd WWEESSTTOONN oonn MMaayy 2222,, 22000066.. SSuubbsseeqquueennttllyy,, 33MM pprroovviiddeedd MMPPCCAA wwiitthh aa m,naapp oonn MMaayy 2266,, 22000066 ddeeppiiccttiinngg tthhee pprrooppoosseedd ssooiill bboorriinngg aanndd ggrroouunnddwwaatteerr mmoonniittoorriinngg wweellll llooccaattiioonnss,, wwhhiicchh wwaass aapppprroovveedd bbyy tthhee MMPPCCAA.. IInn aaccccoorrddaannccee wwiitthh tthheessee ccoommmmunuinciactaitioonnss,, WWEESSTTOONN ppeerrffoorrmmeedd tthhee aaddddiittiioonnaall ssooiill bboorriinngg aanndd ggrroouunnddwwaatteerr mmoonnititoorriinnggwwelelll iinnssttaallllaattiioonn iinn ceaarrllyy JJuunnee 22000066.. AAllssoo,, iinn MMaayy 22000066,, WWEESSTTOONN ccoolllleecctteedd wwaatteerr lleevveell aanndd ddrraawwddoowwnn ddaattaa ffrroomm eexxiissttiinngg momnointiotoririnnggwwelelllss dduurriinngg aa ppllaannnneedd sshhuuttddoowwnn ooff pprroodduuccttiioonn wweellll PPWW-6-6,. TThhee ddaattaa rreeccoorrddeedd dduurriinngg tthhiiss aaccttiivviittyy wweerree uusseedd ttoo eevvaalluuaattee tthhee aarreeaa ooff ggrroouunnddwwaatteerr ccaappttuurree rreessuullttiinngg ffrroomm tthhee rroouuttiinnee aanndd oonnggooiinngg ppuummppiinngg ooff pprroodduuccttiioonn wweellllss PPWW--55 aanndd PPWW-6-6.. TThhee 33MMCoCtotttaaggee (G5rroovvee,, MMNN FFlluuoorroocchheemmiiccaall ((FFCC)) AAsssseessssmmeenntt:." HHyyddrraauulliicc CCa~ppttuurree ZZoonnee EEvvaalluuaattiiool7n wwaass ssuubbmmiitttteedd ttoo tthhee MMPPCCAA iinn NNoovveemmbbeerr 22000066 aanndd iiss iinncclluuddeedd iinn AAppppeennddiixx AAoofftthhiiss rreeppoortr.t. IInnaa lleettteerr ttoo 33MM ddaatteedd JJuunnee 1133,, 22000066,, tthhee MMPPCCAA iinnddiiccaatteedd tthhaatt tthhee pprriimmaarryy oobbjjeeccttiivvee ooff tthhee aasssseessssmmeenntt ((iiddeenntiiffyyiinngg tthhee pprreesseenncceeooff FFCCss iinn vvaarriioouuss mmeeddiiaa)) wwaass mmeet.t. WWiitthh rreessppeecctt ttoo ffoollllooww--oonn aaccttiivviittiieess ((PPhhaassee 22 aasssseessssmmeenntt aaccttiivviittiieess)),, tthhee MMPPCCAA rreeqquueesstteedd tthhaatt 33MM ssuubbmmiitt aann aaddddeenndduumm ttoo tthhee FFCC DDaattaa AAsssseessssmmeenntt RReeppoorrtt ccoonnttaaiinniinngg aa wwoorrkk ppllaann ttoo ffuurrtthheerr ddeeffiinnee tthhee eexxtteenntt ooff FECCss iinn ssoolilss,, eevvaalluuaattee tthhee ggrroouunnddwwaatteerr ttoo ssuurrffaaccee wwaatteerr ppaatthhxwvaayy aanndd ccoonndduucctt aaddddiittiioonnaall aasssseessssmmeenntt ooff tthhee EEaasstt aanndd WWeess:t CCoovveess aannddooftf hthee MMisisssiissssiippppii RRiivveerr,, bbootthh nneeaarr tthhee ffaacciilliittyy aanndd ddoowwnnssttrreeaamm.. TThhee MMPPCCAA aallssoo rreeqquueesstteedd tthhaatt tthhee FFCC aannaallyyttiiccaall ppaarraammeetteerr lliisstt bbee eexxppaannddeedd.. AAccccoorrddiinnggllyy,, 33MM rreettaaiinneedd WWEESSTTOONN ttoo pprreeppaarree tthhee PPhhaassee 22 WWoorrkk PPllaann,, ppeerrfforomr tthhee aasssseessssmmeenntt wwoorrkk,, aanndd pprreesseenntt tthhee ffiinnddiinnggss iinn aa PPhhaassee 22 FFCC DDaattaa AAsssseessssmmeenntt RReepporotr.t. TThhee WWoorrkk PPllaann iinnccoorrppoorraatteedd tthhee rreeccoommmmeennddaattiioonnss ffoorr aaddddiittiioonnaall aasssseessssmmeenntt aaccttiivviittiieess pprreesseenntteedd iinn tthhee FFCC DDaattaa AAsssseessssmmeenntt RReeppoorrtt aanndd rreeqquueessttss mmaaddee bbyy MMPPCCAA iinn iittss JJuunnee 1133,, 22000066 elettteerr ttoo 33MM.. MMPPCCAA aallssoo rreeqquueesstteedd aa vviissiitt ttoo tthhee CCoottttaaggee GGrroovvee SSiittee tthhaatt wwaass ccoonndduucctteedd oonn JJuunnee2211,, 22000066.. DDuurriinngg tthhee vviissiitt,, MMPPCCAA oobbsseerrvveedd tthhee oonn--ssiittee ddiissppoossaall aarreeaass,, EFaasstt aanndd W Weesstt CCoovveess,, MMiissssiissssiippppii RRiivveerr,, aanndd ssooiill bboorriinngg aaccttiivviittiieess aatt tthhee DD99 AArreeaa. me Z:~FOLDI~.S.O-9'3m-cottage grove'Yhase 2 FC Data A~sessmmt RepolrWinal Phase 2 Report.doc | CCoonfnifddeennttiiaall - 33MM IInnssuurraannccee DDooccuummeennttss1-2 22116622..00002244 33MM_EENNVV_0000000033110000 I3MM_MMNNO011448833002255 OOnn JJuullyy 1144,, 22000066,, 33MM ssuubbmmiitttteedd tthhee PPhhaassee 22 FFCCAAsssseessssmmeenntt WWoorrkk PPllaann ((PPhhaassee 22 W Woorrkk Plan) and met with MPCA on July 25, 2006 to discuss comments on the Work Plan. A Plan) and met with MPCA on July 25, 2006 to discuss comments on the Work Plan. A rreevviisseedd WWoorrkk PPllaann,, iinnccoorrppoorraattiinngg cchhaannggeess mmaaddee iinn rreessppoonnssee t1o0 tthhee aaggrreeeemmeennttss rreeaacchheedd dduurriinngg tthhee JJuullyy 2255,, 22000066 mmeeeettiinngg wwaass ssuubbmmiitteteedd t1o0 tthhee M MPPCCAA oonn AAuugguusstt 77,, 22000066.. TThhee PPhhaassee 22 ffiieelldd wwoorrkk wwaass ccoommpplleetteedd iinn tthhee ffaalll ooff 22000066. AA kkeeyy ccoommppoonneenntt iinn tthhee iimmpplleemmeennttaattiioonnofotf thhee PPhhaassee 22 FFCC AAsssseessssmmeenntt pprrooggrraamm wwaass tthhee sseelleeccttiioonn ooff aannaallyyttiiccaall ppaarraammeteetersrs.. SSaammpplleess ccoolllleecctteedd iinn PPhhaassee 11 aanndd iinn tthheeeaeralrlyy ppaarrtt ooff PPhhaassee 22 ((pprriioorr oto tthhee JJuunnee 1133,, 22000066 M MPPCCAA lleetttteerr ttoo 33MM)) wweerree aannaallyyzzeedd ffoorr tthhee ffoolllloowwiinngg FFCCss: +* PePPreelrlfrluuolorrouooooccitraannoeosoiuclsaafctcoiinddaa(t(nPPeFoF(OOiPAAFc)O)S) * PePrelrlfluuoorrooboucttaanneessuullffoonnaattee ((PPFFOBSS)) + PPPeeerrrfflllluuuooorrrooohbheuextxaaannneee sssuuulllfffooonnnaaattteee (((PPPFFFBHHSXx)SS oorr PPFFHHSS)) IInn tthheeiirr JJuunnee 1133,, 22000066 lleetttteerr ttoo 33MM,, M MPPCCAA rreeqquueesstteedd tthhaatt ffuuttuurree ssaammpplliinngg iinncclluuddee aannaallyyssiiss ffoorr aaddddiittiioonnaall FFCC ccoommppoouunndds.s. AAccccoorrddiinnggllyy,, 33MM eexxppaannddeedd tthhe lliissttooff aannaallyytteess ffoorr the Pha2wsorek toinclude the following compounds: the Phase 2 work to include the following compounds: + Perfluorobutanoic acid (PFBA) +* PPPPeeeerrrfflrllluuufooorrlroooupbheueontxartaannnooooiipciccaeaaccacniicidditdd(((aP(PPPFnFFFBoHPPAXeie)AAAc))) *= PPPPeeeerrrrlffflllluuuuoooorrrroooohhhneeeoxppntoataainnncocoiaiciccciaadaccci(ididdP(((PNPPFAFFH)HHxppAAA))) + PPeerrfflluuoorroondoecnaonicciaccaidci(dP(FPNFAD)A) + + PPPPeeeerrrrffffllluuluooourrroooodurdenoocdduaeennccdoaaeinnccooiaiaccncaiaoacdcciii(cdddPF(((PDPPFFFAUDU)ORnAAA))) Perfluorododecanoic acid (PFDoA) IInn aaddddiittiioonn ttoo oovveerraallll ssiittee ccoonnddiittiioonnss aanndd ppootteennttiiaall ppaatthhwwaayyss,, tthhee PPhhaassee 11 aanndd 22 FFCC aasssseessssmmeenntt aaccttiivviittieess aaddddrreesssseedd hhiissttoorriiccaall wwaassttee mmaannaaggeemmeenntt aarreeaass aanndd aarreeaass ooff ppaasstt FFCC mmaannuuffaaccttuurriinngg. TThhrreeee ooff tthhee hhiissttoorriicc wwaassttee mmaannaaggeemmeenntt aarreeaass aarree rreeffeerrreedd 1to0 aass tthhee DD11 AArreeaa ((FFoorrmmeerr HF!-IF TTaarr NNeeuuttrraalliizzaattiioonn BBaassiinn)),, DD22 AArreeaa ((FFoorrmmeerr SSlluuddggee DDiissppoossaall AArreeaa)),, aanndd DDO9 AArreeaa ((FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiitt)).. IInn DDeecceemmbbeerr 22000066,, aatt tthhee rreeqquueesstt ooff tthhee MPCA, 3M submitted a document entitled" nierim RemedialMeasures Evaluation". The MPCA, 3M submitted a document entitled "Interim Remedial.Vleast;res Evahtatio;~". The ppuurrppoossee ooff tthhee rreeppoorrtt wwaass t1o0 eevvaalluuaattee ppoossssiibbllee ooppttiioonnss ffoorr iinntteerriimm rreemmeeddiiaall mmeeaassuurreess CCoonfnifddeennttiiaall - 33MMoIInnsse uurraannccee DDooccuummeennttss13 z:~FOLDI~.S.0-9'3m-collage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 1-3 22116622..00002255 33MM_EENNVV_0000000033110011 I3MM_MMNNO011448833002266 ((IIRRMMss)) iinn tthhee aaffoorreemmeennttiioonneedd tthhrreeee aarreeaass bbaasseedd oonn tthhee rreessuullttss ooff tthhee PPhhaassee 11 aanndd 22 FFCC aasssseessssmmeenntt aaccttiivviittiieess aanndd pprroovviiddee tthhee rraattiioonnaallee ffoorr tthhee iinniittiiaattiioonnooff tthhee IIRRMM.. IInn aa lleetttteerr ttoo 33MM ddaatteedd FFeebbrruuaarryy 11,, 22000077,, tthhee MMPPCCAA aapppprroovveedd tthhee IJnutteerriimm RReemmeeddiiaall MMeeaassuurreess EEvvaalluuaattiioonn rreeppoorrtt ffoorr tthhee DD11,, DD22,, aanndd DD99 AArreeaass,, aanndd rreeqquueesstteedd aa mmeesettiinngg ttoo ccllaarriiffyy tthhee ffaaccttoorrss aanndd aassssuummppttiioonnss ffoorr tthhee pprrooppoosseedd mmuultltiillaayyeerr ccaapp aanndd tthheenn hhaavvee tthhee ""ffiinnaall ddeessiiggnn"" ffoorr tthhee IIRRMM ssuubbmmiitttteedd ttoo tthhee MMPPCCAA..AAtt aa mmeeeettiinngg oonn FFeebbrruuaarryy 77,, 22000077,, 33MM,, WWEESSTTOONN,, aanndd tthhee MMPPCCAA ddiissccuusssseedd aallll ooff tthhee iissssuueess rraaiisseedd iinn MMPPCCAA''ss FFeebbrruuaarryy |1, 22000077 lleetttteerr.. 33MM ssuummmmarairizzeedd tthhee ddiissccuussssiioonnss aanndd rreessuullttss ooff tthhee mmeeeettiinngg iinn aa lleetttteerr ttoo MMPPCCAA ddaatteedd FFeebbrruuaarryy. 2211,, 22000077.. SSuubbsseeqquueennttllyy,, oonn MMaarrcchh 1155,, 22000077,, 33MM ssuubbmmitittteedd ttoo tthhee MMPPCCAA tthhee FFlluuoorroocchheemmiiccaall ((FFCC)) IInntteerriimm RReemmeeddiiaall MMeeaassuurreess WWoorrkk PPllaann ffoorr tthhee DD11,, DD22,, aanndd DDY9 AArreeaass,, wwhhiicchh aaddddrreesssseedd aanndd iinnccoorrppoorraatteedd tthhee iitteemmss ddiissccuusssseedd aatt tthhee FFeebbrruuaarryy 77,, 22000077 mmeeeettiinngg,, iinncclluuddiinngg tthhee 1IRRMM ddeessiiggnn. IInn AApprriill 22000077,, 33MM ccoommmmeenncceedd ddiissccuussssiioonnss wwiitthh tthhee MMPPCCAA ttoo ffoorrmmaalliizzee,, uunnddeerr aa SSeeuttlleemmeenntt AAggrreeeemmeenntt aanndd CCoonnsseenntt OOrrddeerr ((CCoonnsseenntt OOrrddeerr)), tthhee pprroocceessss ooff ccoonndduuccttiinngg rreemmeeddiiaall iinnvveessttiiggaattiioonnss aanndd rreessppoonnssee aaccttiioonnss ttoo aaddddrreessss FFCCss aatt tthhee ssiittee.. TThhee CCoonnsseenntt OOrrddeerr bbeeccaammee eeffffeeccttiivvee oonn MMaayy 2222,, 22000077.. IItt rreeqquuiirreess tthhaatt 33MM ccoonndduucctt aa RReemmeeddiiaall IInnvveessttiiggaattiioonn//FFeeaassiibbiilliittyy SSttuuddyy ((RRUI/FFSS)) wwiitthh rreessppeecctt ttoo rreelleeaassee oorr tthhrreeaatteenneedd rreelleeaassee ooff FFCCss aatt aanndd ffrroomm tthhee ssiittee.. IInn tthhee CCoonnsseenntt OOrrddeerr,, MMPPCCAA ssttaatteess ""AAnn RRI1 RReeppoorrtt aaddddrreessssiinngg aalllloofftthhee iinnvveessttiiggaattiivvee wwoorrkk rreeqquuiirreedd uunnddeerr tthhee MMPPCCAA aapppprroovveedd PPhhaassee 22 FFCU AAsssseessssmmeenntt WWoorrkk PPllaann sshhaallll bbee ssuubbmmitittteedd ttoo MMPPCCAA bbyy JJuunnee 3300,, 22000077.. UUppoonn MMPPCCAA aapppprroovvaallooff tthhee RRII RReeppoorrtt,, tthhee aapppprroovveedd RRII RReeppoorrtt aanndd tthhee AApprriill 22000066 FFuluoorroocchheemmicicaall ((FICC)) DDaattaa AAsssseessssmmeenntt RReeppoorrtt sshhaallll bbee ddeeeemmeedd 1to0 mmeeeett RRII RReeppoorrtt rreeqquuiirermemeenntsts...."". AAccccoorrddiinnggllyy,, ppeennddiinngg MMPPCCAA aapppprroovvaall,, tthhiiss ddooccuummeenntt iiss tthhee RReemmeeddiiaall IInnvveessttiiggaattiioonn RReeppoorrtt,, aanndd ttooggeetthheerr wwiitthh tthhee AApprriill 22000066 FFlhu~oorroocchheemmiiccaall ((FFCC)) DDaattaa AAsssseessssmmeenmt RReeppoorrtt,, mmeeeettss tthhee RRII rreeqquuiirreemmeennttss ffoorr tthhee CCoottttaaggee GGrroovvee SSiittee. IIttiss ffuurrtthheerr ssttaatteedd iinn tthhee CCoonnsseenntt OOrrddeerr tthhaatt bbyy JJuunnee 3300,, 22000077,, 33MM sshhaallll ssuubbmmiitt aann FFSS wwoorrkkppllaann t1o0 aaddddrreessss pprrooppoosseedd rreessppoonnssee aaccttiioonnss.. TThhee FFSS WWoorrkk PPllaann iiss bbeeiinngg ssuubbmmitittteedd ccoonnccuurrrreennttllyy wwiitthh tthhee RRlI rreeppoorrtt easas a sseeppaarraattee ddooccuummeenntt. mee z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc | CCoonfnifddeenntitiaall - 33MM IInnssuurraannccee DDooccuummeennttss1-4 22116622..00002266 33MM_EENNVV_0000000033110022 33MM_MMNNO011448833002277 12 REPORT ORGANIZATION 1.2 REPORT ORGANIZATION is Remedial Invision Repos crgaied to th llving scons: This Remedial Investigation Report is organized into the following sections: + Section 1 -- Introduction. Tis scion comin the se backgeund and Section 1 - Introduction. This section contains the site background and assessment history. + Section 2 -- Site Seting, This ston conan a desepion of the sic Section 2 - Site Setting. This section contains a description of the site llooccaattiioonn,, aarreeaa llaanndd uussee aanndd ddeemmooggrraapphhiiccss,, ssiittee ttooppooggrraapphhyy,, ggeeoollooggyy,, aanndd pariibin hydrogeology. + Scton 3 SummaryofActivities. Ths scion contin if sammy of Section 3 - Summary of Activities. This section contains a brief summary of oT ant wrt soso den ep o000 the Phase 1 field activities that were described in detail in the April 2006 FFlluuoorroocchheemmiiccaall ((FFCC)) DDaattaa AAsssseessssmmeenntt RReeppoorrtt aanndd aa ddeettaaiilleedd ddeessccrriippttiioonn ooff Tr 3d in a rs snipe can wih WPCA. the Phase 2 field activities that were conducted in accordance with the MPCAroad hse 3 Wolk Hn ro oy 10 Sem 3000 approved Phase 2 Work Plan from May to September 2006. + Scton 8. Rene of the Assesment Tis section contin an sxpanton Section 4 - Results of the Assessment. This section contains an explanation hed etn, on mt a conn of M3006 of the data reduction process, a summary and interpretation of the May 2006 Eire Sto ea, a he ets of samp onde ose rs, hydraulic study results, and the results of sampling conducted in on-site areas, Erni en Core and Ahm ov East and West Coves, and the Mississippi River. + Section Summary of Observations. Seton conn o summary of Section 5 - Summary of Observations. Scction 5 contains a summary of ions eo oe of cot Rt. ron ov Conte conclusions based on the results of the entire RI program for the Cottage Goede Grove Site. + Sec6-tDevieloopmennt aud Screening of Response Action Aruives Section 6 - Development and Screening of Response Action Alternatives. TThhiiss sseeccttiioonn ccoonnttaaiinnss aa ssuummmmaarryy ooff tthhee iinniittiiaall tteecchhnnoollooggyy eevvaalluuaattiioonn tthhaatt wwaass mats rps he Loo Posi Teckel Tegsr hd Fo performed to prepare the List of Possible Technology Types to address FCs in ssooilil, ggrroouunnddwwaatteerr aanndd sseeddiimmeennttss aatt tthhee CCoottttaaggee GGrroovvee SSiittee.. IItt aallssoo ccoonnttaaiinnss aa ome eson on the FS Work Flo Cred concen wih is condensed discussion on the FS Work Plan (submitted concurrently with this epoch proves deed explanation Fhe FS pens tt willbe report), which provides a detailed explanation of the FS process that will be ete pons io sama. on oles ag followed so that a response action alternative can be selected and oplemrte she Cotas ron Ste implemented at the Cottage Grove Site. [-- Section 7 - References. TTaabblleess aanndd ffiigguurreess aarree pprroovviiddeedd aatt tthhee eennddooffeeaacchh sseeccttiioonn ffoorr eeaseaooffrserevvieieeww.. CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss rr z:kFOLDI~.S.0-9'3m-cottage grove'l~nase 2 FC Data A~sesslnmt RepoirWinal Phase 2 Report.dec 11--55 22116622..00002277 33MM_EENNVV_0000000033110033 swmnoonzs 3M MN01483028 22.. SSIITTEE SSEETTTTIINNGG 22..11 SSIITTEE LLOOCCAATTIIOONN AANNDD DDEESSCCRRIIPPTTIIOONN The Cottage Grove Site is located approximately three miles southeast of the City of CCoottttaaggee GGrroovvee ((sseeee FFiigguurree 22--11)),, WWaasshhiinnggttoonn CCoouunnttyy,, aanndd iiss aapppprrooxxiimmaatteellyy 11770000 aaccrreess iinn size. The industrial, developed portion of the site is approximately 200 acres. Bordering the site to the south is the Mississippi River; to the west is primarily farmland wwiitthh ssoommee rreessiiddeenncceess;; ttoo tthhee nnoorrtthh iiss UUS.S.. HHiigghhwwaayy 6611 aanndd tf:aarrmmllaanndd wwiitthh ssoommee rreessiiddeenncceess.; aanndd ttoo tthhee ceaasstt aarrec rreessiiddeennttiiaall aarreeaass,, aaggoolflfccoouurrssee,, wwooooddllaannddss,, aanndd ffaarrmmllaanndd.. TThhee ppllaanntt ooppeerraattiioonnss aanndd ddeevveellooppeedd ppoorrttiioonn ooff tthhee ssiittee aarree llooccaatteedd oonn tthhee ssoouutthheerrnn ppaarrtt ooff the property adjacent to the river as shown in Figure 2-2. A few groundwater monitoring and production wells exist on the northern portion of the property, but no industrial or production operations occur there. The Eagles Point Wastewater Treatment Plant (WWTP) is located along the Mississippi River west of the developed portion of the site. It is operated by the Metropolitan Council Environmental Services (MCES). AAddddititiioonnaallllyy,, tthheerree iiss aa ppaarrcceell oonn tthhee iinntteerriioorr ppoorrttiioonn ooff tthhee pprrooppeerrttyy tthhaatt iiss oowwnneedd bbyy CCooggeenntrtriixx,, wwhhiicchh ooppeerraatteess aa ccooggeenneerraattiioonn ppllaannt.t. TThhiiss eelleeccttrriiccaall ppoowweerr ggeenneerraattiioonn ppllaanntt provides steam to the Cottage Grove Site. The property is bisected by a railroad right-of-way. An additional railroad right-of-way is located along the bank of the Mississippi River. 22..22 LLAANNDD UUSSEE AANNDD DDEEMMOOGGRRAAPPHHIICCSS The Cottage Grove Site is located in Washington County. As indicated in Section 2.1, the aarreeaa iimmmmedeidaiatteellyy ssuurrrroouunnddiinngg tthhee ffaacciilliittyy iiss ccoommpprriisseedd pprreeddoommiinnaannttllyy ooff ffaarrmmllaanndd aanndd woodlands, with some residences primarily to the west and east of the facility, a golf course to the east, and a wastewater treatment plant (Eagles Point) to the west. In recent years, Washington County has experienced significant economic and population growth. The continued expansion of the Twin Cities metropolitan area has caused a z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss2-1 33MM_EENNVV_0000000033110044 3M MN01483029 22116622..00002288 nearest city tothe 3V clit proximately 3 mile to the northwest sspprreeaadd ooff ddeevveellooppeedd aarreeaass iinn tthhee rreeggiioonn ssuurrrroouunnddiinngg tthhee 33MM ppllaannt.t. CCoottttaaggee GGrroovvee iiss tthhee nearest city to the 3M facility approximately 3 miles to the northwest. 22..33 TTOOPPOOGGRRAAPPHHYY AANNDD DDRRAAIINNAAGGEE TThhee CCootttaaggee GGrroovvee SSiittee iiss llooccaatteedd oonn aa ffllaatt ttoo ggeennttllyy uunndduullaattiinngg bblluuffff oovveerrllooookkiinngg tthhee mmaaiinn cchhaannneell ooff tthhee MMisisssiissssiippppii RRiivveerr.. RReelliiceff oovveerr mmoosstt ooff tthhee pprrooppeerrttyy iiss oonnllyy oonn tthhee oorrddeerr ooff tteennssoofffefeeett,, rraannggiinngg iinn eelleevvaattiioonn ffrroomm aa hhiigghh ooff 882222 ffeeeett aabboovvee mmeeaann sseeaa lleevveell (ms) on the northern porion to 780 fect msl on the southern portion at the edge of the (msl) on the northern portion to 780 feet msl on the southern portion at the edge of the blu bluff. AAss sshhoowwnn bbyy tthhee ttooppooggrraapphhiicc ccoonnttoouurr lliinneess iinn FFiigguurree 22--11,, tthhee ssoouutthheerrnn ppoorttiioonnooff tthhee ssiittee hhaass bbeeeenn ddeeeeppllyy iinncciisseedd bbyy ssttrreeaammss aanndd ddrraaiinnaaggee bbootthh aeasstt aanndd wweesstt ooff tthhee ppllaanntt ooppeerraattiioonnss aarreea,, aanndd aalloonngg tthhee MMiissisissisippppii RRiivveerr,. TThhee ttooppooggrraapphhiicc rreelliieeff iiss qquuiittee sstteeeepp wwiitthh llaanndd ssuurrffasccee eelleevvaattiioonnss rraannggiinngg ffrroomm aapppprrooxxiimmaatteellyy 778500 ffeeeett mmss!l aatt tthhee ttoopp ooff tthhee bblluuffff ttoo aapppprrooxxiimmaatteellyy 770000 ffeeeett mmssll aatt tthhee rriivveerrbbaannkk. TThhee wweesstteerrnn ddrraaiinnaaggeewwaayy tteerrmmiinnaatteess aatt aa ccoovvee ((WWeesstt CCoovvee)),, wwhhiicchh fflloowwss ttoo tthhee MMisisssiissssiippppii RRiivveerr.. TThhee ceaasstteerrn ddrraaiinnaaggeewwaayy originates from Ravine Lake north of US. Highway 61, and flows intermittently originates from Ravine Lake north of U.S. Highway 61, and flows intermittently following a southerly direction uni it approaches the plant operations area where it following a southerly direction until it approaches the plant operations area where it rreecceeiivveess tthhee NNPPDDESE-Sp-epremnintittteedd ddiisscchhaarrggeess ffrroomm tthhee ppllaanntt''ss wwaasstteewwaatteerr ttrreeaattmmeenntt aanndd cooling water system. The drinagenay terminates at a cove (East Cove), which cooling water system. The drainageway terminates at a cove (East Cove), which discharges o the Misisipp River discharges to the Mississippi River. 22..44 GGEEOOLLOOGGYY AAss sshhoowwnn oonn ccrroossss sseeccttiioonn AA--AA"' ((FFiigguurree 22--33)), tthhee CCootttaaggee GGrroovvee SSiitee iiss ddiirreecctllyy uunnddeerrllaaiinn bbyy ffiillll mmaatteerriiaall aanndd uunnccoonnssoolliiddaatteedd ggllaacciioo--fflluuvviiaall ddeeppoossiittss ooff pprroobbaabbllee QQuuaatteerrnnaarryy aaggee.. TThhee ttrraannsseecctt uusseedd iinn tthhe ccrroossss sseeccttiioonn iiss sshhoowwnn iinn FFiigguarree 22--44. IInntthhee nnoorrtthheerrnn ppoorrttiioonn ooff tthhee pprrooppeerrttyy,, uunnccoonnssoolliiddaatteedd ddeeppoossiittss rraannggee ffrroomm aa ffeeww- ffeeeett ttoo aa ffeeww tteennss ooff ffeesett iinn tthhiicckknneessss.. GGrroouunnddwwaatteerr wwaass noott oobbsseerrvv'eedd ttoo bbee pprreesseenntt iinn tthhee uunnccoonnssoolliiddaatteedd ddeeppoossiittss iinn tthhiiss aarreeaa.. TThhee uunnccoonnssoolliiddaatteedd ddeeppoossiittss iinnccrreeaassee iinn tthhiicckknneessss ffrroomm nnoorrtthh ttoo ssoouutthh aaccrroossss tthhee site and ae over 100 feet thick near the Missisipp River where a burid bedrock valley site and are over 100 feet thick near the Mississippi River where a buried bedrock valley exists. The bedrock surface closely mimics the present-day topography and the cliff ine exists. The bedrock surface closely mimics the present-day topography and the cliff line z :~F C~LDI~S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss2-2 33MM_EENNVV_0000000033110055 W_MNOT483030 3M MN01483030 22116622..00002299 ooff tthhee bbeeddrroocckk ppaalleeoo--bblluuffff aappppeeaarrss ttoo bbee llooccaatteedd ppaarraalllleell ttoo tthhee MMisisssiissssiippppii RRiivveerr.. TThhee boring for monitoring well MW-11 encountered talus slope materials at approximately 135 feet below ground surface (bgs) (drill cuttings were identified as Oneota Dolomite) and drilled into the Jordan Sandstone at a depth of 168 feet bgs. Thus, south of the paleo- bblluuffff,, uunnccoonnssoolliiddaatteedd ggllaacciioo--fflluuvviiaall mmaatteerriiaallss eexxcceeeedd 113355 ffeeeett iinn tthhiicckknneessss,, aanndd aatt lleeaasstt locally, become important sources of groundwater supply. An erosional unconformity lies between the base of the unconsolidated deposits and the bedrock beneath the facility. The youngest bedrock in subcrop at the facility is the Shakopee and Oneota formations of the Prairie du Chien Group (early Ordovician age). The Prairie du Chien group is predominantly comprised of fine to medium grained dolomite and sandy dolomite with some inter-bedded quartzite sandstone. Inspection of wweellll ccoommpplelettiioonn llooggss ffoorr mmoonniittoorriinngg aanndd pprroodduuccttiioonn wweellllss aatt tthhee ffaacciilliittyy iinnddiiccaatteess tthhaatt tthhee Shakopee and Oneota formations underlie much of the northern portion of the property, through the central plant area south to a paleo-bluff (the boundary of the buried bedrock valley) as shown in Figure 2-3. These features are also shown in Figure 2-5 that presents the bedrock geologic map for the site area. Underlying the Shakopee and Oneota Formations is the Jordan Sandstone, which is a medium to coarse-grained quartzite sandstone. Several production wells at the site tap this formation for water supply. The St. Lawrence Formation (a confining layer - shale uunniitt)) iiss pprreesseenntt aatt tthhee bbaassee ooff tthhee JJoorrddaann SSaannddssttoonnee,, aapppprrooxxiimmaatteellyy 220000 ffeeeett bbeellooww tthhee central portion of the site. 22..55 WWAATTEERR UUSSAAGGEE AANNDD HHYYDDRROOGGEEOOLLOOGGYY All site production and monitoring wells are completed in the upper water-bearing stratigraphic units at the site. The upper water-bearing units consist of the Prairie du CChhiieenn GGrroouupp,, JJoorrddaann SSaannddssttoonnee,, aanndd uunnccoonnssoolliiddaatteedd ddeeppoosistists.. DDuuee t1o0 tthhee pprreesseennccee ooff tthhee paleo-bluff, the Jordan Sandstone and Prairie du Chien Group are hydraulically connected to the unconsolidated deposits near the Mississippi River. Since no aquitard separates the Prairie du Chien and the Jordan sandstone, they are often considered as one z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : 22-33 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00003300 33MM_EENNVV_0000000033110066 3M MN01483031 hhyyddrroollooggiicc uunniitt. LLiitteerraattuurree iinnddiiccaatteess tthhaatt tthhee uunnddeerrllyyiinngg SStt. LLaawwrreennccee SShhaallee iiss nnoott considered an aquifer but rathera confining unit due to its low permeability. (Lindholm, considered an aquifer but rather a confining unit due to its low permeability. (Lindholm, al, 1974) et al., 1974). TThheerree aarree ssiixx pprroodduuccttiioonn wweellllss ((PPWW--11 tthhrroouugghh PPW W--66)) tthhaatt ssuuppppllyy wwaatteerr ffoorr iinndduussttrriiaall aanndd ssaanniittaarryy ppuurrppoosseess aatt tthhee cil. facility. TThhe ssiixx pprroodduuccttiioonn welelllss wweerre iinnssttaalllleedd dduurriinngg tthhee ppeerriioodd 119944771to 11997700,. W Weellllss PPWW--11 tthhrroouugghh PPWW--44 aarree ccoommpplleetteedd iinn tthhe JJoorrddaann SSaannddssttoonnee.. WWeellllss PW-S and PW-5 are completed entirely in the unconsolidated deposits near the PMiWss-i5ssiapnpdi RPivWer-.6 are completed entirely in the unconsolidated deposits near the Mississippi River. TThhee ggrroouunnddwwaatteerr ffrroomm ffoouurr ooff tthhee pprroodduuccttiioonn wweellllss ((PPWW--22 tthhrroouugghh PPWW--55)) iiss bblleennddeedd oonn aa ccoonnttiinnuuoouuss bbaassiiss iinn aa wwaatteerr ssuuppppllyy ddiissttrriibbuuttiioonn ssyysstteemm ffoorr vvaarriioouuss ssiittee nneeeeddss,, iinncclluuddiinngg pprroodduuccttiioonn aanndd ssaanniittaattiioonn.. BBootttlledd wwaatteerr oorr wwaatteerr raed treated bbyy ggrraannuullaarr aaccttiivvaatteedd ccaarrbboonn (GACY is supplied for drinking and the on-site cafeteria. The remaining two production (wGelAlsC)aries ustuiplipzleieddinfoderpdernidneknitnlgy aonnd athpeeroino-dsiictebcaasfsetfeorira.siTteh-ewirdeemfaiirneinpgrottwecotipornod(uPcWt-io1n) wanedllsnoanre-cuotnitliazcetd cionodleipnegndfeonrtltyheonsitaepienrcioindeicratboarsis(PfoWr-)s.ite-Awllidegrfoiruendpwraotteecrtiocnom(iPnWg-1in) acnodntanconw-ictohntparcotduccotoiloinngprfoocrestshees siitereisntceidnearfaetorrus(PeWat-6t)h.e oAnl-lsigterowuansdtwewaatetrercotrmeiantgmenint cfaocniltiatcyt, wpritihorptroodaunctNioPnDEpSro.cpeesrsmeisttisedtredaitsecdhaarfgteertuostehatetahseteornn-dsirtseiwnaagsetewwayate(EratsrteaCtmoveen)t flaecaidliitnyg, ptoriotrheto MainssNisPsDipEpiS-pReivremr.itteTdhedisocnh-asrigtee tgorothunedveeaastteerrn odbrtaaininaegdewfaoyr (nEona-stcoCntoavcet) cloeoadiinngg itsosuthpepleMmeisnstisesdipbpyi gRroivuenrd. sTathee roon-msitteheg3roMunWdowodabteurryobStaiieneldocaftoerd nnoornt-hcoonfttahcet cploaonltinwghiischsuipspcleomnveenyteedd btyo tgrhoufncdiwlaytebryfruonmdetrhger3oMundWpoiopdibnugrOynScieteultoiclaizteedd fnoortchooolfinthg,e plant which is conveyed to the facility by underground piping. Once utilized for cooling, tthhee nnoonn--ccoonnttaacctt ccoooolliinngg wwaatteerr iiss ddiisscchhaarrggeedd ttoo aann oonn--ssiittee ccoooolliinngg wwaatteerr ppoonndd pprriioorr ttoo aann NPDES-pernitted discharge to the casern drainageway where iti combined with the NPDES-permitted discharge to the eastern drainageway where it is combined with the Wastewater trestmen discharge wastewater treatment discharge. TTwwoo aaddddiittiioonnaall wweellllss ((PPWW--77 aanndd PPWW--88)) aaree uusseedd ffoorr wwaatteerr ssuuppppllyy oonn aann aass nneeeeddeedd bbaassiiss. PPWW--77 iiss llooccaatteedd aatt tthhee TTrraapp RRaannggee aanndd PPAWV--88 iiss llooccaatteedd aaddjjaacceenntt t0o.2a gguuaarrdd hhoouussee aatt tthhee planntt eennttraannccee.. IInn aaddddiittiioonn ttoo tthhee pprroodduuccttiioonn wweelllls,, tthhee ggrroouunndduwaatteerr mmoonnititoorriinngg wweellll nneevtwwoorrkk ccoonnssiissttss ooff 31 groundwater monitor wells, Eight monitor wells (MW-1 through MW-8) were 3in1staglrloeudndduwriantegr am3oMnitsotrudwyebllest. wEeeignht19m74onaintodr 1w97e5llsin(MorWde-r1 tothmroauingthaiMn Wan-8o)ngwoienrge irnesctoarldledofdugrrionugndawa3tMerstluevdeyls.betMwoeneintor197we4llanPdZ-119475 wiansosrdubesretqouemntaliyntaainddeand ofnorgotihnigs record of groundwater levels. Monitor well PZ-14 was subsequently added for this a Z:~FOLDI~.S.0-9'3tn-cottage grove'~:hase 2 FC Data A~sessmmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummenetnsts.2-4 3MM_ENEVN_V0000000033110077 W_MNOT483032 3M MN01483032 22116622..00003311 aaccttiivviittyy.. AA nniinntthh mmoonniittoorr wweellll ((MMWW--99)) wwaass iinnssttaalllleedd oonn tthhee wweesstt ssiiddeeooftf hthee ppllaanntt ttoo mmoonniittoorr ggrroouunnddwwaatteerr ccoonnddiittiioonnss aatt tthhee ffoorrmmeerr ccooaall ssttoorraaggee ppiillee aarreeaa llooccaatteedd nnoorrtthhoofftthhee iinncciinneerraattoorr ffaacciilliittyy.. AAnn oolldd pprroodduuccttiioonn wweellll wwaass iiddeennttiiffiieedd iinn 11998811 oonn tthhee eeaasstt ssiiddeeoofftthhee ppllaanntt nneeaarr tthhee wwaasstteewwaatteerr ttrreeaattmmeenntt ffaacciilliittyy aanndd wwaass rreeddeessiiggnnaatteedd aass mmoonintitoorr wweellll MMWW-1100.. DDuurriinngg tthhee 11998800ss,, mmoonniittoorr wweellllss MMWW--1111 tthhrroouugghh MMWW--1166 wweerree iinnssttaalllleedd ttoo mmoonniittoorr sseevveerraall ppaasstt wwaassttee ddiissppoossaall aarreeaass aanndd aann aammmmoonniiuumm ssuullffaattee rreelleeaassee nneeaarr tthhee WWWWTTPP.. IInn tthhee llaattee 119999005s mmoonniittoorr wweellllss IMVWl-W1-717,, MMWW-I-1S8,, aanndd MMWW--1199 wweerree iinnssttaalllleedd ttoo mmoonniittoorr g`grorouunnddwwaatteerr ccoonnddiititoinosanatst tthhee cclloosseedd aasshh//sslluuddggee llaannddffiillll ssoouutthh ooff tthhee iinncciinneerraattoorr.. MMoonintitoorr wweellllss MMWW-1-10011 aanndd MMWW--110022 wweerree iinnssttaalllleedd iinn 22000022 aatt aa ffoorrmmeerr ddiissppoossaall aarreeaa ((DD11 AArreeaa)) ttoo aasssseessss tthhee aarreeaa ssoouutthheeaassttoofftthhee pprroodduuccttiioonn aarreeaa.. IInn JJuunnee 22000066,, eeiigghhtt aaddddiittiioonnaall mmoonniittoorr wweellllss ((MVMWW--110033 tthhrroouugghh MMWW-1-11100)) wweerree iinnssttaalllleedd nneeaarr ppaasstt wwaassttee ddiissppoossaall aarreeaass ((DDI1//DD22,, DDS5,, DD99 aanndd tthhee CCoottttaaggee GGrroovvee SSiittee WWWWTYPP aarreeaa)) aass ppaarrtt ooff tthhee PPhhaassee 22 FFCC AAsssseessssmmeenntt PPrrooggrraamm.. FFiigguurree 22--44 sshhoowwss tthhee llooccaattiioonnss ooff tthhee mmoonniittoorriinngg aanndd pprroodduuccttiioonn wweellllss aa t tthhee ffaacciilliittyy.. FFiigguurree 22--66 ddeeppiiccttss tthhee ccoonnffiigguurraattiioonn ooff tthhee wwaatteerr ttasbbllee ssuurrffaaccee aatt tthhee ppllaanntt iinn MMaayy 22000066 dduurriinngg ccoonnddiittiioonnss wwhheenn PPWW--55 aanndd PPWW--66 wweerree nnoott ppuummpipning.g GGrroouunnddwwaatteerr eelleevvaattiioonn ddaattaa iinnddiiccaattee aa ssoouutthheerrllyy ggrroouunnddwwaatteerr ggrraaddiieenntt ttoowwaarrdd tthhee MMisisssiissssiippppii RRiivveerr.. TThhee ccaallccuullaatteedd hhyyddrraauulliicc ggrraaddiieenntt iiss oonn tthhee oorrddeerrooff00..0011 fftU/fftt GGrroouunnddwwaatteerr lleevveellss hhaavvee bbeeeenn mmeeaassuurreedd sseevveerraall ttiimmeess aanndd tthhee wwaatteerr ttaabbllee ssuurrffaaccee ccoonnffiigguurraattiioonnss hhaavvee rreemmaaiinneedd rreellaattiivveellyy ccoonnssiisstteennt.t. T"Thhee ppuummppiinngg ooff tthhee pprroodduuccttiioonn wweellllss,, PPWW--55 aanndd PPWW--0066,, hhaass ddeepprreesssseedd tthhee ggrroouunnddwwaatteerr ttaabbllee nneeaarr tthheessee wweellllss wwiitthh hhyyddrraauulliicc ggrraaddiieennttss ddiirreecctteedd ttoowwaarrddss tthhee pprroodduuccttiioonn wwelelllss.. IInn MMaayy 22000066,, aass ppaarrtt oofftthhee PPhhaassee 22 aasssseessssmmeenntt aaccttiivviittiieess,, WWEESSTTOONN ccoolllleecctteedd wwaatteerr lleevveell aanndd ddrraawwddoowwnn ddaattaa ffrroomm eexxiissttiinngg mmoonniittoorriinngg wweellllss dduurriinngg aa ppllaannnneedd sshhuuttddoowwnn ooff pprroodduuccttiioonn wweellll PPWW-6-6.. TYhhee ddaattaa rreeccoorrddeedd dduurriinngg tthhiiss aaccttiivviittyy wweerree uusseedd ttoo eevvaalluuaattee tthhee aarreeaa ooff ggrroouunnddwwaatteerr ccaappttuurree rreessuullttiinngg ffrroomm tthhee ppuummppiinngg ooff pprroodduuccttiioonn wweellllss PPWW--55 aanndd PPWW-6-6.. TThhee33MMCCoottttaaggee GGrroovvee,, MMNN FFlluuoorroocchheemmiiccaall ((FFCC)) AAsssseessssmmeenntt:: HHyyddrraauulBicc CCaappttuurree ZZoonnee EEvvaalluuaattiioonn wwaass ssuubbmmiitttteedd ttoo tthhee MMPPCCAA iinn NNoovveemmbbeerr 22000066 aanndd iiss iinncclluuddeedd iinn AAppppeennddiixx AA ooff tthhiiss rreeppoortr.t. T`Thhee rreessuullttssoofftthhee hhyyddrraauulliicc ccaappttuurree zzoonnee eevvaalluuaattiioonn aarree ssuummmmarariizzeedd iinn SSeeccttiioonn 44.. me z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss2-5 33MM_EENNVV_0000000033110088 I3MM_MMNNO011448833003333 22116622..00003322 dr BLE CHRON Jo BS THA Bee fa L Sp RlSeaw Ly aCi a lig ee G af e TSSeEgrNa OdRaUubLm SAm ONy rf2E fT JTyL N(S e eE E ge 4 Er ia Nae I pS yf NET ee TR hHoErsRclv ade ese e eR t Co ISE fl FW nag SE or 1 I CRN XN BS Tee BgSoUNO TuT mJB aeonNaT nrrRe yEf ld Aa ATHE"id Shoo ede ayo / GES ad 1 1 Banat CAS en OR eel hE mr AW Eel f,(ois ele Sh Bint a em i Phi ey 4 JEL AF ; =J ntfy eta av TL Ay IRL SA Al an fri 5 Agd w alf g REL'Wtad 52 aTt N,. 3 wv TToeTere iz i [ry 7 = , LSAonmew Sg A ine bE o fin ON A Ss T] TIE (Corben hilar DOooC~amennts mo ceiooosao 7 rnniled 3M MN01483034 22116622..00003333 Le re 5 AoeR SAE CE lS e (iee NE I fe ! : po Za ORE | pn A 4> | 7 / / SOEb ea Y BFe pra0:n: t ail a: dlJani) 77 TT FY za be jh, 7J i BY poe a : Aga I oa 1 : ih i ND485035 3M MN01483035 22116622..000034  on 8 = A pEakiET A A it i,E i H i an h Ea Aa N CL N S t AN eGa E NIN V a 0 i: (2(29 Ea \ A Vo 2 cm anua d 4 an n 83 nIdaN mdN NA C VL os 8|B Re CoE |: 8 32:NAN BEE yon ((5B2e 1-111 I La a l B3E EN ee wO 3: P Ta Emir ((82 # 8 cmz=p 8 --8 8 3 8 8 3 3% CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00003355 33MM_EENNVV_0000000033111111 suoraesoss 3M MN01483036 5 3 B of Ws 4 A bh ma oy YEa EE aV nPea J SE ' FEIT EY _BPTERY CE LR y 7 ] li BL | al pas Bl\ s --" 7 NN a pd 42 | H- i PF | 22116622..00003366 3M MN01483037 i WEE riN ZSi IN f PE re B$ ana SEENE ! Ful \/ i Ne = ff IN = FGs aslie A J i Gond Nise FAN lyo 7 iil tae Ne o Wo e N lkC A eT R-- am HE TY ~edrock Geology of the ~t. Paul P~rk Quadrangle, wast]lngton and Er fn, Dakota Count|~, MN ~ Jo~;lan Sandstone ~ Prairi~ clu Chin Group Lawrence Fonmatior~ Frar~o~ia Fo~at~on Sets 07P-0446-5 FFIIGGUURREE 22--55 BBEEDDRROOCCKK GGEEOOLLOOGGIICC MMAAPP COTTAGE GROVE SITE CCoonfnifddeennttiiaall ~- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033111133 3M MN01483038 22116622..00003377 \ 8 Ba aS B3a5na Sa oI AN Ng ct FR lL 4 &_ Sh A EM : lt gy esNEA RSE a ; , Tom[apseeTE E n rE Ca R ya Xe CEE R [i p roe m >N CS S RO AA TV Ee ,Semaeal I Rea)a Ff neal V ou bE o etA STEeN --=F "n%HEe CTNA BBe0.A n 0 M A. dri LE o ig , wePLYa 4 - oy: REpe0 ae abo HS :a EeNETE or a a. nN tm Sh) oy eht o] i Legenod: me| Legend: N (}roundwatcr Elcvation Conlour (fl MSI ,) Q Monitoring Well 500 O Production Well 1,000 pa ---- 2,000 Feet Confretate-smimsuran 686.47 (h-oundwater Elevation (ft MNI ,) Map U S Source. Departmenl of -- Agriculture, Farm Services Ager~cy, D~gftat Orthorect~fied Images (DO~), Minnesota, 2063 FIGURE 2-6 GROUNDWATER ELEVATION CONTOUR MAP NON-PUMPING CONDITIONS an SSR 8 MAY 2006 COTTAGE GROVE SITE 3M ENV 00003114 3M MN01483039 22116622..00003388 3. SSUUMMMMAARRYY OOFF AACCTTIIVVIITTIIEESS = Throughout this document, references are made to Phase 1 results as necessary to provide aa mmoorree ccoommpplleettee uunnddeerrssttaannddiinnggoofftthhee aasssseessssmmeenntt ddaattaa aanndd ggrroouunnddwwaatteerr ppaatthhwwaayyss aanndd aass a basis for the Phase 2 activities. The complete presentation of Phase 1 information is provided in the Fluorochemical (FC) Data Assessment Report, (WESTON, April 2006), hereafter referred to as the Phase 1 FC Data Assessment Report. A highlights summary of the Phase 1 field activities and results, which formed the basis for the Phase 2 field work, is presented in Subsection 3.1. 33..11 PPHHAASSEE 11 FFIIEELLDD AACCTTIIVVIITTIIEESS The scope of the Phase 1 FC Assessment is summarized in this section since it will be ccoonnssiiddeerreedd iinn ccoommbbiinnaattiioonn wwiitthh tthhee PPhhaassee 22 pprrooggrraamm,, tthhee ccoommpplleettee RRII pprrooggrraamm ffoorr tthhee Cottage Grove Site, pending MPCA approval. Activities conducted under the Facility-wide Fluorochemical (FC) Investigation Work PPllaann ((WWEESSTTOONN,, 22000044)),, hheerreeaafflteerr rreeffeerrrreedd ttoo aass tthhee PPhhaassee 11 FFCC WWoorrkk PPllaann,, wweerree iinniittiiaatteedd with a file review in January 2005. This review was conducted to collect information on the historic Cottage Grove Site waste generation, waste disposal, or treatment both onsite and off-site. The field assessment commenced in March 2005 and was completed in AAuugguusstt 22000055.. IItt ccoonnssiisstteedd ooff tthhee ffoolllloowwiinngg:: Groundwater and Additional Assessment - In March and May 2005, field data and groundwater samples were collected from 21 existing monitoring wweellllss,, ssiixx pprroodduuccttiioonn wweellllss,, aanndd ttwwoo wwaatteerr ssuuppppllyy wweellllss aatt tthhee CCoottttaaggee GGrroovvee Site. One monitoring well (MW-6) could not be sampled due to an obstruction in the well borehole. A sample of water from the tap at Bldg. 116 (cafeteria) wwaass ccoolllleecctteedd aafftteerr ggrraannuullaarr aaccttiivvaatteedd ccaarrbboonn ((GGAACC)) ttrreeaattmmeenntt uunniti.t. + AAsidtddediti(tiiWooonnaoaldlllbyyu,, rttyhheeSifftooeuu)rr appnuudmmptpihiennggcowwmeeblllilssneaadtt ttdhhieescffhooarrrmmgeeerrf33rMoMm WWtohoeoosdedbbuwuerrlyyls,ddiisswpphooisscaahll ppsirrtooevvii(ddWeeonnooodnnb--uccoroynnttaSaccittte)pprraoonccdeessssthwewaatcteoermr ffbooirrnettdhheedCCiosoctthttaaagrggeeeGGrfrrooovvmee tSShiitetees,,ewwweerereellsss,aamwmphplilceehdd totiinmmceee,, pttehhreemddioissnccthhhaafrroggreethffrrroeomemmtthoheenthCCosotittntaagMgeearGGcrrhoo,vvAeepSSriiiltt,eeannnoodnn-M-ccoaonyntta2ac0ct0t 5pp.rrAooccteetsshsse wwsaaatmteeerr retention pond also was sampled. Z:~FQLDI~.S.O-9'3m-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-1 22116622..00003399 33MM_EENNVV_0000000033111155 3M MN01483040 Soil Assessmeut - In May 2005, soil assessment work included 16 soil bboorriinnggss iinnssttaalllleedd ttoo ddeepptthhss rraannggiinngg ffrroomm 2255 ttoo 7700 ffeeeett bbeellooww ggrroouunndd ssuurrffaaccee ((fftt bgs) and 112 composite soil samples collected at 5-ft intervals from the soil borings. In addition, fifty (50) surface soil samples were collected from two shallow depths at 25 locations in drainageways~ areas where FCs were handled~ and ootthheerr ggeenneerraall ssiittee llooccaattiioonnss.. Sediment and Surface Water - In August 2005, a sediment and surface water assessment was conducted at the Cottage Grove Site and the Mississippi River. Twenty (20) sediment samples and nine surface water samples were collected from the East and West Coves and the Mississippi River. Six sediment samples, co-located with six surface water samples, were collected from the 0-10 cm depth interval at locations upstream, adjacent, and downstream of the facility in the Mississippi River. Sediment samples were collected from three locations in the East and West Coves and upstream of each cove. One surface water sample was collected from each cove. Also, one ssuurrffaaccee wwaatteerr ssaammppllee wwaass ccoolllleecctteedd uuppssttrreeaamm ooff tthhee EEaasstt CCoovvee bbuutt tthhee drainageway upstream of the West Cove was dry. Fish - In August 2005, fish sampling was performed at three reaches of the Mississippi River, one upstream, one adjacent to the plant, and one ddoowwnnssttrreeaamm.. AA ttoottaall ooff6622 ffiisshh wweerree ccoolllleecctteedd iinncclluuddiinngg 1111 ssmmaallllamnoouutthh bbaassss,, 30 channel catfish and 21 bluegill sunfish. Whole body or filet tissue samples were prepared from the collected specimens for chemical analyses. File Review and Interviews - A file review and interviews with retired and current employees were conducted to collect information on the historical waste generation, waste disposal, or treatment both on-site and off-site. All of the samples collected under the Phase 1 FC assessment program were submitted to Exygen Research in State College, Pennsylvania, for analyses of PFOA, PFOS, PFHS, and PFBS. A subset of the soil samples were also selected for grain size distribution and total organic carbon (TOC) analyses. Results of the Phase 1 assessment were reported in tthhee FFCC DDaattaa AAsssseessssmmeenntt RReeppoorrtt ((WWEESSTTOONN,, AApprriill 22000066)),, aanndd tthhee pprriimmaarryy rreessuullttss wwhhiicchh supported the Phase 2 field program, are highlighted in the following subsection. 3.1.1 Results of the Phase 1 FC Assessment and Data Needs The findings from the file review relative to waste disposal locations utilized by the ffaacciilliittyy wweerree ssuubbmmiitttteedd ttoo tthhee MMPPCCAA dduurriinngg aa JJuunnee 1100,, 22000055 mmeeeteitning.g TThhiiss rreevviieeww indicated that, other than on-site waste disposal, there were three key off-site waste z :~F OLDI~S .0-9' 3m-c ollage grove'Y~nase 2 FC Data A~sessinmt RepolrWinal Phase 2 Report.dec CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-2 33MM_EENNVV_0000000033111166 3M MN01483041 22116622..00004400 disposal areas that received Cottage Grove wastes. These included: the former Oakdale Disposal Site (Oakdale Site), the former Woodbury Site, and the former Washington County Landfill. The Oakdale Site and the Woodbury Site are being assessed by 3M under a related but separate work plan. However, an initial site assessment was performed at the Woodbury Site under the FC Work Plan covered by the Phase 1 Data Assessment Report. The MPCA is addressing the Washington County Landfill under its CClloosseedd LLaannddfifillll PPrrooggrraamm.. It was found that the facility personnel interviews corroborated information from the file review- and provided additional details. A new disposal area was brought up during the personnel interviews was the possible existence and location of a former on-site sludge disposal pit. No documentation of this pit was evident in the file review and it had not been assessed. This former on-site sludge disposal pit was designated as D9 for assessment during Phase 2. The D8 area had been assessed by a previous removal action in November 1985. It was agreed with MPCA that no further investigation was needed in this area due to the limited site access and proximity to pumping well PW-6. Groundwater -The highest FC concentrations were detected in groundwater samples from monitoring wells MW-12 downgradient of the D5 - Former Solids Burn Pit Area, MW-14 downgradient of the D8 - Former Waste Disposal Area, and MV-101 downgradient of the D1 - Former HF Tar Neutralization Basin. In these areas, PFOA concentrations ranged from 150 to 1,863 ppb and PFOS from 80 to 324 ppb. TThhee hhiigghheesstt FFCC ccoonncceennttrraattiioonnss ddeetteecctteedd iinn ggrroouunnddwwaatteerr ssaammpplleess ccoolllleecctteedd ffrroomm ppuummppiinngg wells were detected at pumping well PW-6 (155 ppb PFOA). PW-6 is downgradient of the MW-14. Groundwater elevation data collected from the monitoring wells in March 2005 show that the influence of the pumping wells is most significant in the central plant area and is reduced with increasing distance from this area. With respect to groundwater at the Cottage Grove Site, the following data needs were identified:i Z:~FQLDI~.S.O-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc . CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-3 33MM_EENNVV_0000000033111177 3M MN01483042 22116622..00004411 * Groundwater quality and movement Gdirsopuosnadlwpaittenreeqdueadlit1y0baendchamraocvteermizeendt. iinn tthhee aarreeaa ooff tthhee DD99 ffoorrmmeerr sslluuddggee disposal pit needed to be characterized. + TgTrhhaeedippeoonttteenontftiiatalhlemmDooSv,veeDmmIe,enntatnoodffDgg2rrooAuurnneddawsw,aathteearrdttnoootssuubrreffeaancceechwwaaratateecrrt,,erppiaazrrettdiiccuullaarrllyy ddoowwnn gradient of the D5, D1, and D2 Areas, had not been characterized. = BBeetttteerr ddeeffiinniittiioonnooff tthhee hhyyddrraauulliicc iinnfflluueenncceeooffppuummppiinngg wweellllss PPWW--55 aanndd PPWW-6-6.. `SoilS--TTohheehhiiigghhleesstt ccoonncceennttrraattiioonnss ooff FFCCss wweerree ffoouunndd iinn tthhee DD22 aanndd DDI1 AArreeaass.. IInn tthhee DD22 --- FFoorrmmeerr SSlluuddggee DDiissppoossaall AArreeaa,, tthhee hhiigghheesstt FFCC ccoonncceennttrraattiioonnss ((uupp ttoo 1122,,335500 ppppbb PPFFOOSS)) wweerree ffoouunndd iinn tthhee sslluuddggee,, wwhhiicchh iiss llooccaatteedd aapppprrooxxiimmaatteellyy 55 ttoo 2200 At't bbegss.. LLoowweerr ccoonncceennttrraattiioonnss ((rraannggiinngg ffrroomm 44.3399 ttoo 779944 ppppbb PPFOOSS)) wweerree ddeetteecctteedd iinn tthhee uunnddeerrllyyiinngg nnaattiivveesosioli,l, wwhhiicchh bbeeggiinnss aatt aapppprrooxxiimmaatteellyy 2200 1to0.2255 fttbbgss. IInntthhee DDI1 -~ FFoorrmmeerr HHEF TTaarr NNeeuutrtraalliizzaattiioonn BBaassiinn AArreeaa,, tthhee hhiigghheesstt FFCC ccoonncceennttrraattiioonnss ((uupp ttoo 44,552200 ppppbb PPFFOOAA)) wweerree ddeetteecctteedd iinn tthhee 55 ttoo 3300 fftt bbygss ddeepptthh rraannggee iinn bboorriinnggss ccoonnssttrruucctteedd jjuusstt oouuttssiiddee tthhee ssuussppeecctteedd llooccaattiioonnooff tthhee bbaassiinn ssttrruuccttuurree aanndd ddeeccrreeaasseedd bbeellooww 3300 fbt bsgs iinn tthhee nnaattiivvee ssooiillss ((rraannggiinngg ffrroomm 5533..99 t1o0 337755 ppppbb)).. IInn tthhee DDS5 FFoorrmmeerr SSoolliiddss BBuurmn PPiitt AArreeaa,, ccoonncceennttrraattiioonnss ooff PPFEOOSS ((uupp ttoo 22.,331100 ppppbb)) aanndd PPFFOOAA ((uupp t1o0 11,,337755 ppppbb)) wweerree ddeetteecctteedd iinn ssaoiill ssaammpplleess ttoo aa ddeepptthhooff aapppprrooxxiimmaatteellyy 1155 fftt bbgess iinn tthhee oonnee ssaoiill bboorriinngg ccoonnssttrruucctteedd iinn tthhiiss aarreeaa.. LLoowweerr ccoonncceennttrraattiioonnss wweerree ddeetteecctteedd aatt lToowweerr ddeepptthhss ((3344..55 aanndd 4466..88 ppppbb PPFFOOSS aanndd 2211..88 aanndd 4422..55 ppppbb PPFFOOAA)). AAtttthhee FFiirree TTrraaiinniinngg AArreeaa ((FFTTAA)),, PPFFOOSS wwaass ddeetteecctteedd iinn llooccaalliizzeedd aarreeaass aatt ccoonncceenntrtraattiioonnss. uupp ttoo 11,,882200 ppppbb pprriimmaarriillyy iinn sshhaallllooww ssooiillss ttoo aa ddeepptthh ooff 5 ffit bbggss,, wwiitthh lloowweerr ccoonncceennttrraattiioonnss ddeetteecctteedd aatt lloowweerr ddeepptthhss.. "TThhee ffoolllloowwiinngg ddaattaa nneeeeddss wweerree iiddeennttiiffiieedd [f'oorr ssooiillss aatt tthhee CCoottttaaggee GGrroovvee SSiittee: = DiDnS5 sizFeF,oorrhmmaeedrrSnSoolotilidbdsesBeBnuumrdnefPPiiintteAdArreweaia.t. hTThhriiesssapraeerceata,, twwohhitichcehh ihissoarapipzpopnrrioaxolixmeiaxttmeelnayt2t2oaefacclrFreeyCss itccnhooinnscsceiaeznrneter,at.raathtiOaioondnnlssy.n.ooHHt niisbestetooberorniirccidnrregeefcciwonoarredsddsslwddoiiciddtahtnneoodrtet isssnphheotochwwit s tssaoppreeectcahiifefaiicnchdlloiirmsmioziiitlotssnstooaarrml bbpoelouxeuntsneddnafatrrrioioeemfsstF[fh'oioCrsr tbbhooirrsiinnaggreeeax.xhhOiibbniilttyeeddoncceoonnbcceoenrntintrrgaattwiiooannsssolofofcFFatCCesds ppinrriimtmhaairsriillayyreaaatt 0a0tntdoo 15 ft bs. soil samples 15 ft bgs. from this FTA- Additional scl sampling FdiTsAturbeAd ddduietiotonaclonssotilucstaimonplainngd wtwoaasosbntneaeeiedndeebdedttiiennr ttdhheeefiFFniTTtAAionsssiinnccee ssooiill hhaadd bbeeeenn disturbed due to construction and to obtain better definitions, CCoonfnifddeentnitaiall-- 33MMoIInnsse uurraannccee DDooccuummeennttss34 z:~FOLDI~.S.0-9'3m-collage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 3-4 22116622..00004422 33MM_EENNVV_0000000033111188 I3MM_MMNNO011448833004433 + D9 - Former Sludge Disposal Pit. Ths newly identified area had not been D9 - Former Sludge Disposal Pit. This newly identified area had not been aasssseesssseedd oorr cchhaarraacctteerriizzeedd aanndd wwiillll bbee rreeffeerrrreeddttooaass tthhee DD99 AArreeaa. `Sediment - FCs were detected in sediment in the coves and Mississippi River. Generally, Sediment - FCs were detected in sediment in the coves and Mississippi River. Generally, upsrcam levels were ess than downstream upstream levels were less than downstream. PPFFOOAA sseeddiimmeenntt ccoonncceennttraattiioonnss iinn tthhee EEaasstt CCoovvee ((1111..77 t1o0 2288..77 ppppb)) wweerree ccoommppaarraabbllee tfoo tthhee WWeesstt CCoovvee ((44..1111 t1o0.3388.77 ppppbb)),. PPFFOOSS sseeddiimmeenntt ccoonncceennttrrataitoinosnisn tihnthee EEaasstt CCoovvee ((224.42.2 t1o0/226677 ppppbb)) aarree hhiigghheerr tthhaann aatt tthhee WWeesstt CCoovvee ((115.52.2 ttoo 9911.11 ppppbb)).. HHiigghheerr PPFFOOSS concentrations were detected nth shallow sediments (0-10 cn) ofthe East Cov than in tchoencdeeneptreartiosnesdiwmeernetdse(t1e0c:t2e0daimn)the shallow sediments (0-10 cm) of the East Cove than in the deeper sediments (10-20 cm). IInntthhee MMiissisissisippppii RRiivveerr,, aavveerraaggee sseeddiimmeenntt ccoonncceennttrraattiioonnss aatt ssaammppllee llooccaattiioonn RRI1,, RR22,, aanndd RRe4 wweerree nnoott qquuaannttiiffiieedd ((NNQQ)) oorr nnoott ddeetteecctteedd ((NNDD).). TThhe aavveerraaggee sseeddiimmeenntt ccoonncceennttrraattiioonnss ((8$.2285 aanndd 113.32.2 ppppbb,, rreessppeeccttiivveellyy)) ooff PPFFOOSS aanndd PPFFOOAA wweerree ddeetteecctteedd aatt ssaammppllee llooccaattiioonn R3, whichisadjacent o the operating plant potion ofthe property. R3, which is adjacent to the operating plant portion of the property. The following daa needs wer identifiedfo the sediment The foll++owiCACndgodonidcdaneotnanctarnaleeteioodnnns-sswotiofteferFreFaCraCiesdsaetiinsnntsaiiesfmiepdoedlidiimnmnfeogensrnttthaaett depth (below sediment: depth (below 1100 ccmm) Additional on-site area sampling Surface Water- The erage concentrationsof FCs in the East Cove wate sample were arate Surface tWhaanterthe- TchoencaevnetrraagteiocnosncdeenttercattieodnsinoftFhCe sWinestthe CEoavsteCowavteewr atsearmpslaem. pleInwethree gMriesaitseriptphianRivtehre, PcoFnOcAenatrnadtioPnFsOSdectoenccteendtraintiotnhse weWreesNt DCoovreNQwaattetrhesaRml ptleh.rouIgnh Rithe M saimspslisisnigppliocRaitvioenrs,.PFTOheAoannlyd qPuFaOntSifcioabnlceencotrnacteiontnrsawtieornesNofDPoFrONSQanadt thPeFRO1At(h0r.o0u9g8haRnd4 0sa.m13p2lipnpg,lorceastipoenctsi. vTelhye) oinnlythequwaantteifriasbalmeplceosncweenrtreatdioetnesctoefdPaFtOdSowannsdtrPeFaOmAlo(0t.i0o98n aRSn,d 0.132 ppb, respectively) in the water samples were detected at downstream location RS. W Wiitthh rreessppeecctt ttoo sseeddiimmeenntt aanndd ssuurrffaaccee wwaatteerr,, tthhee ffoolllloowwiinngg ddaattaa nneeeeddss wweerree iiddeennttiiffiieedd:: 25a possible pathy. = CCoonncecnetnrtaratitioonnss,, iiff aannyy,, ooff FFCCss iinn ggrroouunnddwwaatteerr eenntteerriinngg tthhee rriivveerr ((ppoorreewwaatteerr)) as a possible pathway. = DDiissttrriibbuuttiioonn,, iiff aannyy,, ooff FFCCss iinn ssuurrffaaccee wwaatteerrss aanndd sseeddiimmeenntt eexxtteennddiinngg aaccrroossss the iver nd farther upstream and downstream, the river and farther upstream and downstream. ish- The analytical results indicate that FCs have been detected in ish samples (whole Fish - The analytical results indicate that FCs have been detected in fish samples (whole bbooddyy aanndd ffiilleett)) ccoolllleecctteedd ffrroomm tthhrreeee rreeaacchheess ooff tthhee MMisisssiissssiippppii RRiivveerr iinn tthhee iimmmmeeddiiaattee Confidential - 3M Insurance Documents rr | z:kFOLDI~S.0-9'3m-cottage grove'l~nase 2 FC Data A~sessmmt RepoirWinal Phase 2 Report.dec 33.-55 Confdential- 3M Insurance Documents 22116622..00004433 M3M_ENEVN_V0000000033111199 a3MW_MNNo0r1a4s83o0s4s4 vicinity of the Cottage Grove Site. The FCs were detected in each of the three species sampled: Channel catfish, Bluegill sunfish, and Smallmouth bass. The following conclusions had been identified for Mississippi River fish: The current data set represents one limited round of fish sampling conducted in a finite area in the Mississippi River. 3.1.2 Phase 1 Recommendations Substantial characterization was completed at the Cottage Grove Site as part of the Phase 1 work conducted in 2005. However, data needs were identified and additional recommendations were made. The recommendations were implemented in the Phase 2 iinnvveessttiiggaattiioonn.. 33..22 PPHHAASSEE 22 FFIIEELLDD PPRROOCCEEDDUURREESS The Phase 2 FC assessment field activities were conducted in accordance with the FC WWoorrkk PPllaann aanndd HHeeaalltthh aanndd SSaaffeettyy PPllaann ((HHAASSPP)) ((AAppppeennddiixx BB ttoo tthhee PPhhaassee 11 FFCC WWoorrkk Plan, December 2004) and the "Phase 2 FC Assessment Work Plan", WESTON, July 2006 (revised August 7, 2006). Field procedures were consistent with MPCA site characterization and sampling guidance. Any deviations from the FC Work Plan are identified in the following sections of this Phase 2 Data Assessment Report. The Phase 2 field activities included: DIDnI1s/t/aDDl2l2a,,tiDoD9n9,,aDDnSd5asananmddpttlhhienegffooorrfmm8eerrgCCrootouttntaadggweeGaGtreorrovmveeoSnSiiitttoeerWWinWgWTwTPePllpspooinnnddsts.h.e vicinity of Collection of soil samples during the drilling of the monitoring wells, 10 soil boring locations in the D5 and D9 areas and 6 hand auger locations in the vicinity of the Fire Training Area. Collection of sediment and surface water samples from the East and West CCoovveess.. ((EEaasstt CCoovvee,, 77 sseeddiimmeenntt ssaammppllee llooccaattiioonnss aanndd 22 ssuurrffaaccee wwaatteerr llooccaattiioonnss.. West Cove, 3 sediment sample locations and 2 surface water locations.) Cssaaommlplpellceetssio(n(4433ofllooccsaaattmiioopnnlsse))s,, ssfruuorrmffaacceethwweaattMeerrissssaiasmmspippllpeesis ((R77i33vellrooccaiantticioolunndss))ingaan;nddpssoeerddeiiwmmaeetnnetrt Z:~FOLDI~.S.O-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : 33--66 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033112200 3M MN01483045 22116622..00004444 samples (73 locations). Porewater samples were collected at a discrete interval tthhrroouugghh aa tteemmppoorraarryy wweellll ppooiinntt iinnssttaalllleedd aatt aa ddeepptthhooff 66--iinncchheess ttoo 11 ffoooott iinnttoo the river bottom sediments. Performance of a hydraulic capture zone analysis based on the drawdown effects from the plant production wells, PW-5 and PW-6. Table 3-1 summarizes the sample numbers and types of samples by area. All samples for FFCC aannaallyyssiiss wweerree sseenntt ttoo,, aanndd aannaallyyzzeedd bbyy,, EExxyyggeenn RReesseeaarrcchh iinn SSttaattee CCoolllleeggee,, PPAA.. 33..22.11 GGrroouunnddwwaatteerr MMoonniittoorriinngg WWeellll IInnssttaallllaattiioonn During the period of June 12 and June 19, 2006, eight groundwater monitoring wells (MW-103 through MW-110) were installed at the Cottage Grove Site (Figure 3-1). The rraattiioonnaallee aanndd bbaassiiss ffoorr eeaacchh llooccaattiioonn iiss ddiissccuusssseedd iinn SSuubbsseeccttiioonn 33..33 wwhhiicchh ddeessccrriibbeess tthhiiss Phase 2 effort for the various waste management areas. The monitoring wells are 2-inch ID with stainless steel screens and low carbon steel rriisseerrss.. TThhee wweellllss wweerree iinnssttaalllleedd uussiinngg hhoollllooww--sstteemm aauuggeerr aanndd sspplliitt ssppoooonn ssaammpplliinngg techniques. Continuous split spoon samples were collected and composited for laboratory aannaallyyssiiss oovveerr 55 ffoooott iinntteerrvvaallss ttoo aa ddeepptthh ooff 2255 ffeeeett.. BBeellooww 2255 ffeeeett,, ssaammpplleess wweerree ccoolllleecctteedd eevveerryy 55 ffeeeett ttoo tthhee ttoottaall ddeepptthhooff tthhee bboorriinngg ffoorr lliitthhoollooggiicc ddeessccrriippttiioonn oonnllyy.. TThhee bboorreehhoollee was logged by an experienced geologist noting color, texture, moisture content, and any odors or discoloration. The soils were also screened using an organic vapor meter (OVM) and readings were recorded on the soil boring logs. The monitoring wells were developed during the week of June 26, 2006 and sampled during the week of September 4, 2006 (See Subsection 3.2.2). The new monitoring well elevations and locations were surveyed for horizontal and vertical control. Table 3-2 summarizes the well construction details for all of the Phase 1 and Phase 2 site m`moonniittoorriinngg wweellllss.. TThhee ssuurrvveeyy iinnffoorrmmaattiioonn aanndd tthhee ssooiill bboorriinngg aanndd wweellll ccoonnssttrruuccttiioonn llooggss are provided in Appendix B. z :~F OLDI~S .0-9' 3tn-c ottage grove'~:hase 2 FC Data A~sessmmt RepolrWinal Phase 2 Report.doc or : 33.-77 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00004455 33MM_EENNVV_0000000033112211 3M MN01483046 3.2.2 Groundwater Sampling Groundwater sampling of the newly installed monitoring wells was conducted during the week of September 4, 2006. In accordance with the Phase 2 FC Work Plan, monitoring wells were purged a minimum of three well volumes before sampling was conducted. Temperature, specific conductivity, and pH were measured during the purging process so that representative groundwater samples could be collected after these parameters ssttaabbiilliizzeedd.. TThhiiss ddaattaa wwaass rreeccoorrddeedd oonn tthhee wweellll eevvaaccuuaattiioonn!/ssaammpplliinngg ffoorrmmss.. FFoolllloowwiinngg purging, the wells were allowed to stabilize to minimize the suspended particulate in the sample media. Groundwater samples were collected using disposable polyethylene bailers and poured into sample containers provided by the laboratory. The containers were promptly sealed, labeled, and placed into ice chests. The sample information was entered onto a Chain-of-Custody (COC) that accompanied the samples to the laboratory. The analyses were performed by Exygen Research in State College, Pennsylvania for the twelve FC compounds as defined in Subsection 1.1. Figure 3-1 shows the groundwater monitoring well locations at the facility and Table 3-3 presents a groundwater sampling summary. A copy of the well evacuation/sampling forms is provided in Appendix C. 33..22.33 SSooiill BBoorriinngg aanndd SSooiill SSaammpplliinngg AAccttiivviittiieess In addition to soil samples collected for FC analyses during the monitoring well installation, ten soil borings (D5B01 through D5B06 and DgSB01 through D9SB04) wweerree iinnssttaalllleedd oonn JJuunnee 2200 aanndd 2211,, 22000066 iinn tthhee DDS5 aanndd DD99 aarreeaass.. TThhee llooccaattiioonnssooff tthhee ssooiill borings are shown in Figure 3-1 and the rationale tbr each boring is described in SSuubbsseeccttiioonn 33..33.. CCoommpopsoisittee ssooiill ssaammpplleess wweerree ccoolllleecctteedd aatt ssppeecciiffiieedd iinntteerrvvaallss ttoo bboorriinngg termination for descriptive logging and analytical testing. The soil was logged by the onsite WESTON geologist noting color, texture, moisture content, and any odors or discoloration. The soils were also screened using an organic vapor meter (OVM) and readings were recorded on the soil boring logs. A copy of the soil boring logs is provided in Appendix B. Z:~FOLDI~.S.0-9'3m-cottage grove'l~nase 2 FC Data A~sesslnmt RepoirWinal Phase 2 Report.doc or : 33-88 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00004466 33MM_EENNVV_0000000033112222 3M MN01483047 Alter descriptive logging, soil samples were collected from 0-3 inches bgs, 0.5-5 ft bgs, and every 5-ft interval to boring termination at each location. This procedure is consistent with the subsurface soil boring and sampling conducted during the previous Phase 1 field work, except that the 0-3 inch bgs surface soil sample was added as part of the soil boring sampling. Soil samples were submitted to Exygen Research in State College, PPeennnnssyyllvvaanniiaa ffoorr aannaallyysseess ooff tthhee ffoouurr FFCC ccoommppoouunnddss ffoorr ssooiill ssaammpplleess ccoolllleecctteedd iinn JJuunnee 22000066 aanndd tthhee ttwweellvvee FFCC ccoommppoouunnddss ffoorr ssooiill ssaammpplleess ccoolllleecctteedd aafftteerr JJuunnee.. 33..33 OONN--SSIITTEE AARREEAASS SSAAMMPPLLIINNGG TThhiiss sseeccttiioonn pprreesseennttss tthhee PPhhaasse2e2 ssooiill aanndd ggrroouunnddwwaatteerr FFCC aasssseessssmmeenntt pprrooggrraamm bbyy aarreeaa aass defined in the Cottage Grove Site FC Data Assessment Report (WESTON, April 2006). During the Phase 1 FC assessment program, the highest concentrations of FCs were ddeetteecctteedd iinn ssooiillss aanndd ggrroouunnddwwaatteerr pprriimmaarriillyy iinn oonn--ssiittee aarreeaass wwhheerree wwaassttee rreessiidduueess aanndd sludges were disposed. Some of these areas were further evaluated as part of this Phase 2 assessment to better define the vertical and lateral extent of FCs as will be discussed in the following subsections. Based on the recommendations presented in the Phase 1 FC Data Assessment Report and discussions with MPCA, further evaluation of the following on-site areas was conducted under this Phase 2 FC assessment program: 2 D1/D2 Area - Former ttF Tar Neutralization Basin/Former Sludge Disposal Area D5 Area Former Solids Burn Pit Area D9 Area - Former Sludge Disposal Pit Fire Training Area Production wells PW-5 and PW-6 (hydraulic capture zone evaluation) The Phase 2 FC assessment program for these areas included the installation and sampling of soil borings and monitoring wells as summarized in previous subsections. The locations are shown on Figure 3-1. z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : 33-99 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033112233 3M MN01483048 22116622..00004477 3.3.1 D1/D2 Area - Former HF Tar Neutralization Basin/Former Sludge DDiispoossaall AArrea The D1 Area was constructed as a concrete-lined basin and was used from the mid 1960s to the early 1970s to neutralize hydrofluoric acid (HF) tars with lime. The area was closed, material removed, and filled with local soils in the early 1970s. The D2 Area, located west of and adj acent to the D 1 Area, received sludge or dredged material from the w`waasstteewwaatteerr ttrreeaattmmeenntt ppoonnddss aatt tthhee ceaasstt eennddooff tthhee CCoottttaaggee GGrroovvee SSiittee.. TThhee ssiittee wwaass cclloosseedd onsen and covered between 1973 and 1975. Objectives The obj e ctives of Phase 2 activities at the D1/D2 Area were: To assess the presence of FCs in groundwater and soils immediately ddoowwnnggrraaddiieennttoofftthheeDD1l//DD22 AArreeaa.. To characterize the potential movement of this groundwater to the Mississippi River. GGrroouunnddwwaatteerr WESTON installed two groundwater monitoring wells, MW-103 and MW-104, in the unconsolidated deposits, downgradient of the DI/D2 Area. Both groundwater monitoring wweellllss wweerree iinnssttaalllleedd ttoo aa ddeepptthhooff8888 fftt bbggssiinnttoo tthhee uunnccoonnssoolliiddaatteedd ddeeppoosistitss.. SSooiill During well installation activities, a total of 12 composite soil samples were collected for analytical testing from the two soil borings (MW-103 and MW-104) using split spoon samplers continuously to approximately 25 ft bgs. Soil samples were collected from 0-3 iinncchheess bbegss,, 00..55--55 fftt bbegss,, aanndd eevveerryy S5--fftt iinntteerrvvaall ttoo 2255 fftt bbegss aatt eeaacchh bboorriinngg llooccaattiioonn.. TThhee remaining depth of the boring was logged and screened with an organic vapor meter. Z:~FOLDI~.S.O-9'3tn-cottage grove'~:hase 2 FC Data A~sessmmt RepolrWinal Phase 2 Report.doc or : 33--1100 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00004488 33MM_EENNVV_0000000033112244 3M MN01483049 3.3.2 D5 Area - Former Solids Burn Pit Area The D5 area, west of the current wastewater treatment operations was used for burning organic solids wastes and disposal of inorganic solid waste generated from plant production operations. Skimmings of sludge from the original wastewater pond were also reportedly placed in this area. The area was covered with 3 to 7 feet of fill and there are onset no visual ground surface indications of the boundaries of this site. Objectives The objectives of Phase 2 activities at the D5 Area were: a To assess the presence of FCs in groundwater immediately downgradient of the D5 Area. To characterize the potential movement ol'this groundwater to the Mississippi River. To further characterize the extent of FCs in soils and residues in this area. Groundwater Based on the Phase 2 Work Plan, it was planned to install a single monitoring well to approximately 100 it bgs, downgradient of the D5 Area. However, during well iinnssttaallllaattiioonn oonn JJuunnee 1199,, 22000066,, aa sshhaallllooww wwaatteerr--bbeeaarriinngg zzoonnee wwaass eennccoouunntteerreedd aatt approximately 40 ft bgs. It was decided to install a shallow monitoring well in this zone iinn aaddddiittiioonn ttoo tthhee aaddjjaacceenntt ddeeeeppeerr mmoonniittoorriinngg wwelell,l. As shown in Figure 3-1, the wells are located between existing monitoring wells MW-15 and MW-16. The two new monitoring wells, MW-109 and MW-110, were installed in uunnccoonnssoolliiddaatteedd ddeeppoossitisttoos depptths of 466..5 and 1100 fit bbegss,, resppeeccttiivveellyy.. Soil During well installation activities, a total of six composite soil samples were collected for analytical testing from the soil boring at MXV-109 using split spoon samplers ccoonnttiinnuuoouussllyy ttoo aapppprrooxxiimmaatteellyy 2255 fftt bbggss.. TThhee rreemmaaiinniinngg ddeepptthh ooff tthhee bboorriinngg wwaass llooggggeedd Z:~FOLDI~.S.O-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc or : 33--1111 CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00004499 33MM_EENNVV_0000000033112255 3M MN01483050 aanndd ssccrreeeenneedd wwiitthh aann oorrggaanniicc vvaappoorr mmeeteterr.. AAddddititiioonnaallllyy,, iinn aaccccoorrddaannccee wwiitthh tthhee PPhhaassee 22 WWoorrkk PPllaann,, ssiix ssooiill bboorriinnggss ((DDSSBBO0I1 tthhrroouugghh DDS5BB0066)) wweerree iinnssttaalllleedd uussiinngg aa GGeeoopprroobbee iinn thhee DDS5 AArreeaa oonn JJuunnee 2200,, 22000066 aatt tthhee llooccaattiioonnss sshhoowwnn iinn FFiigguurree 33--11.. WWiitthh tthhee eexxcceeppttiioonn ooff DDS5BBO0S5,, tthhee ssooiill bboorriinnggss wweerree iinnssttaalllleedd ttooaa ddeepptthhooff aapppprrooxxiimmaatteellyy 2255 fftt bbagss.. SSaoiill bboorriinngg DDS5BBO0S5 wwaass iinnssttaalllleedd ttoo rreeffuussaall aatt aa ddeepptthh ooff 1100 fft bbegss.. AA ttoottaallooff 3333 ccoommppoossiittee ssooiill ssaammpplleess wweerree ccoolllleecctteedd ffoorr ddeessccrriipptiivvee llooggggiinngg aanndd aannaallyyttiiccaall tteessttiinngg.. SSooiill ssaammpplleess wweerree ccoollllecctteedd ffrroomm 00--33 iinncchheess bbegss,, 00..55--55 ft bbegss,, aanndd eevvee~ry 55--f1t iinntteerrvvaall t(o0 2255 fft bbegss aatt ceaacchh boborriinngg llooccaattiioonn. 33..33..33 DD99 AArreeaa-- FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiitt T"Thhee DDO9 aarreeaa wwaass iiddeennttiiffiieedd dduurriinngg tthhee PPhhaassee 1| aasssseessssmmeenntt aass aa ffoorrmmeerr sslluuddggee ddiissppoossaall ppiitt aanndd hhaadd nnoott bbeeeenn pprreevviioouussllyy aasssseesssseedd oorr cchhaarraacctteerriizzeedd iinn tthhee ffiieelldd. OObbjjeeccttiivveess TThheeoobbjejeccttiivveessooffPPhhaasse2e2 aaccttiivviittieess aatt tthhee DD99 AArreeaa wweerree:: + TdTooownaagssrssaeessdssiettnhhtee oppfrretehsseeennaccreeeaooff FFCCss iinn ssooiill aanndd ggrroouunnddwwaatteerr aatt aanndd iimmmmedeidaiatteellyy downgradi ent of the area. + TTooaasssseessss ggrroouunnddwwaatteerr flloowwddirireeccttiioonn frroomm tthhiiss aarreeaa. + TRTiooveccrh,haaroraarcctnteoerrritizzheetttohhweearppodotteetnhntetiiaarlalvmmionoevvelememaedenintntgoof0ftththhiises ggFrarosotuunnCddowwvaeatteerr ttoo tthhee MMisisssiissssiippppii RiveL or north toward the ravine leading to the East Cove GGrroouunnddwwaatteerr WWEESSTTOONN iinnssttaalllleedd tthhrreeee ggrroouunnddwwaatteerr mmoorniittoorriinngg wwaellllss ((MMWW-1- 10055,, MMWW-1-01066,, aanndd MMWW-110077)) iinn uunnccoonnssoolliiddaatteedd ddeeppoossiittss aatt tthhee DD99 AArreeaa ffrroomm JJuunnee 66 tthhrroouugghh JJuunnee 99,, 22000066. MMoonnititoorriinngg wweellllss MMWW-1-10055,, MMWW-1-01066,, aanndd MMWW--110077 wweerree iinnssttaalllleedd ttoo ddeepptthhssooff9696..55,, 9955,, aanndd 9922 fftt bbegss,, rreessppeeccttiivveellyy.. SSooiill DDuurriinngg wweellll iinnssttaallllaattiioonn aaccttiivviittiieess,, a ttoottaall ooff 1188 ccoommppoossiittee ssooiill ssaammpplleess wweerree ccoolllleecctteedd ffoorr aannaallyyttiiccaall tteessttiinngg ffroomm tthhee ssooiill bboorriinnggss aatt MMWW-1-10055,, MMWW-1-10066,, aanndd MMWW--110077 ttoo z :~F C~LDI~.S .0-9' 3m-c ottage grove'l~lase 2 FC Data A~sessmmt RepoirWinal Phase 2 Report.doc oe 5123-12 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 22116622..00005500 33MM_EENNVV_0000000033112266 S3MM_MMNNO011448833005511 aapppprrooxxiimmaatteellyy 2255 Iftt bbggss.. TThhee rreemmaaiinniinngg ddeeppth ooff tthhee bboorriinngg ffrroomm 2255ftt t1o0.9999 ft bbegss wweerree llooggggeedd aanndd ssccrreeeenneedd uwsiinngg aann oorrggaanniicc vvaappoorr mmeetteerr. AAddddiitoionnaallyly,, bbaasseedd oonn tthhe PPhhaassee 22 WWoorrkk PPllaann,, ffoouurr ssooiill bbroirinnggss ((DD9IBB0O1 tthhrroouugghh DDI9BO0S4)) wweerree iinnssttaalllleedd nin tthhee DDO9 AArreeaa aatt tthhee llooccaattiioonnss sshhoowwnn iinn FFiigguurree 33--11. . TThhee ssooiill bboorriinnggss wweerree iinnssttaalllleedd ttoo aa ddeepptthh ooff approvimately 25 ft bys. A total of 24 composite soil samples were collcted for adepspcrroixpitmivaetelloygg2i5ngftanbdgsa.nalAytitcoatlalteostfin2g.4 Acfotmerpodseistcerispotiilvesalmogpgliensg,wseoriel scaomlplelcetsedwefroer descriptive logging and analytical testing. After descriptive logging, soil samples were boringlocation ccoolllleecctteedd ffrroomm 00--33 iinncchheess bbggss,, 00..55--55 ffit bbggss,, aanndd eevvee~ry S5--fftt iinntteerrvvaall ttoo 2255 ffti bbggss aatt ceaacchh boring location. 33..33.44 W Waassttoewwaatteerr TTrreeaattmmeenntt PPllaanntt AArreeaa WWEESSTTOONN iinnssttaalllleedd aann aaddddiittiioonnaall ggrroouunnddvweaatteerr mmoonniittoorriinngg wweellll,, MMWW-1-10088,, iinnttoo. tthhee uunnccoonnssoolliiddaatteedd zzoonnee aanndd iimmmmedeidaiatteellyy ddoowwnnggraraddiieenntt ooff tthhee ffaacciilliittyy''ss wwaasstteewwaatteerr ttrreeaattmmeenntt ppllaanntt ((WWWWTTPP)) ppoonnddss ttoo pprroovviiddee ggrroouunnddwwaatteerr ddaattaa iinn tthhiiss aarrceaa,, wwhhiicchh hhaadd nnoott been previously assessed. MW-108 sas installed on June 14 and 15, 2006 to depth of b1ee0n 3fptr.ebvy5iso.usDlyeapssetsosewda.tMerWat-1M0W8-w1a0s8inisstaalplperdosoinmaJutenley1945 fantdb1y5s,. 2S0oi0l6staompaldeesptwheroel~ c1o0l3l.e5ctfetdbfgrso. mDtehpetmhortoitwcraitenrgwaet lMWbo-r1i0n8g 1is apdperpotxhimofa2te5ly1 95 ft bgs. Soil samples were collected from the monitoring well boring to a depth of 25 ft. 33.33.55 FFiirree TTrraaiinniinngg AArreeaa TThhee FFiirree TTrraaiinniinngg AArreeaa ((FFTTAA)),, llooccaatteedd oonn tthhee wweesstteerrnn ppoorrttiioonnooff hthee ppllaanntt wwaass uuitilliizzeedd aass arly as 1968 to tet fire ighing foams. The foams ae propritay 3M products that ecaornltyinas F1Cs9.68 Ptroiotresttofi1re971f,ighmtuincghfooafmtsh.e Trheseidfuoaalms sanadre lpirqouipdrsietfarroym3tMhepfriordeufcitgshtthinagt cexoenrtcaiinsesFCdiss.cPharriogredtoto1a9r7e1a, dmrauicnhageosf athned trehseindutaolstheanddailinqaugideswafyrolmocathteed fwireestfiogfhttinigs earxeea.rciIsnes19d7i2s,chaanrguenddetrogarroeuanddrsationraaggeestaanrkd wthaesnctoonstthreucdtreadintaogceowlalyetlofcluaitdesdfwroemsttohef tfhirise area. In 1972, an underground storage tank was constructed to collect fluids from the fire accumulated fluids are pumped imo a tanker truck and discharged to the onsite ffiigghhttiinngg aaccttiivviittiieess.. IInn 11998811,, aa lliinneedd ppoonndd wwaass ccoonnssttrruucctteedd ffoorr ccoonnttaaiinniinngg fflluuiiddss.. TThhee accumulated fluids are pumped into a tanker truck and discharged to the on-site wwaasstteewwaatteerr ttrreeaattmmeenntt ppllaanntt. OObbjjeeccttiivvee presence and extentof FCs in shalloe sil n this ares TThhee oobbjjeeccttiivvee ooff PPhhaassee 22 aaccttiivviittiieess aatt tthhee FFiirree TTrraaiinniinngg AArrceaa wwaass ttoo ffuurrtthheerr aasssseessss tthhee presence and extent of FCs in shallow soils in this area. Confidential - 3M Insurance Documents rr | z:~FC~LDI~.S.0-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 33--1133 Confdential- 3M Insurance Documents 3MM_ENEVN_V0000000033112277 W3M_MNMONT04184833005522 22116622..00005511 Soil Soil Additional Phase 2 sampling of shallow soils was performed on September 3, 2006 to AcodndfiitriomntahlePPhhaassee21 sraesmulptlsinagndoftoshfaurlltohwer asosielssswcausrrpeenrtfocromndeidtioonnSaenpdtecmonbceernt8r,at2i0o0n6s tion cthoenI0]r5mftthbesPhinatseerva1l.resSuhlatsllaonwdstiolthsratmhpelresaseserses ccuorlrleencttecdoantdfitiivoensloacnadticoonnicnenthtriastiaorncas ains the 0-5 ft bgs interval. Shallow soil samples were collected at five locations in this area as sashdhjoouwwsntnediinninFFitigghueurrfeeie33l-d-22.t.o position the borings in areas where surface TThhee llooccaattiioonnss aass pprreesseenntteedd iinn tthhee PPhhaassee 22 FdFrCCaiWnWaogorerkkocPPclularansn. Thewweerree aadmjpulsteesd winertehecoflileeldctteod pusoisnitgionhtahnedbaourginergswiinthasrecals swahmpelreessuerrfiaeceveddraaitna0g-e and 2:3 occurs. The bsaems pilmeesrvwaelrse Tcholelescatemdpluessinwgera ehasnendtaougEexrywgiethn sRoeisl esaarmchpleins rSeattrieevCeodllae!ge0,-1Pef!nnasnydlv2a-3nifat bagnds ianntaelryvzaelsd. oTrhethseam12plFeCs wcoemrpeosuenndtst.o Exygen Research in State College, Pennsylvania and analyzed for the 12 FC compounds. 33..33..66 HHyyddrraauulliicc CCaappttuurree ZZoonnee EEvvaalluuaattiioonn A hydraulic capture zone evaluation was performed on two ofthe plant production wes A hydraulic capture zone evaluation was performed on two of the plant production wells aroundwater moving toward the rive, PPWW--55 aanndd PPWW--66 llooccaatteedd aalloonngg tthhee MMisisssiissssiippppii RRiivveerr.. TThhee pprroodduuccttiioonn wweellllss eexxttrraacctt groundwater moving toward the river. OObbjjeeccttiivveess The objcives of conducting a hydraulic capture zone evaluation at production wels PW-S and PW.6 were The objectives of conducting a hydraulic capture zone evaluation at production wells PW-5 and PW-6 were: + TTleoovelddeedttaemtrnmaiicnneeotthlheeseexxttdeeunnrttinoogff aggrropoluuannnddnwweadtaetemrraiccnaatppetunurareencaaett stthhheeussteedowwweenllllssofuuspsiirnnoggduwcwtaaittoeenrr lweevlell PdWa-t6a. collected during a planned maintenance shutdown of production well PW-6. + aqTTuooitcceoolrllleeucnctdtewwralayttieenrrglleehvveeellfddaaaittaa.ffoorr ccaallcuullaattiioonn ooff hhyyddrraauulliicc ppaarraammeetteerrss ffoorr tthhee aquifer underlying the facility. HHyyddrraauulliicc SSttuuddyy From May 2 to May 8, 2006, WESTON conducted a hydraulic study at the Cottage FGrroomveMSiatye 120 atoseMssaythe8,wa2t0e0r6,leWvelErSeTsOpoNnsecoinndfuaccitleidtyagrhoyudnrdausalitcerstmuodnyitaotrithneg wCeoltltsagfeo GthreosvheuStidtoewtno oafssoeses otfhtehweaotne-rslietveeplrroedsupcotnisoen iwnelflasc,ilPitWy-6g.rouInndprweaptaerratmioonniftoorritnhge wplealnlsnetdo ttheempsohruatdryowsnhuotfdoonwenooffthperoodnu-cstiiteonprwoedlulctPiWo-n6w, eWllsE, SPWTO-6N. Ipnlpacreepdatrraatinosndufcoerrsthewiptlhandnaetda tleomggpeorrsariyn schiguhttdomwonnitoofrpirnogduwecltilosn(wMeWl-l4P,WM-6W,-1W0E,STMOW-N11p,lacMeWd-t1r2an,sdMuWc-er1s3w,itPhZ-d1a4t,a loggers in eight monitoring wells (MW-4, MW-10, MW-11, MW-12, MW-14, PZ-14, Confidential - 3M Insurance Documents rr | - z:~FC~LDI~.S.0-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 33--1144 Confdential- 3M Insurance Documents 22116622..00005522 3MM_ENEVN_V0000000033112288 aW_mNorasaoss 3M MN01483053 MMWW-1-155,, aanndd MMWW-1-166)) aanndd ttwwoo pprroodduuccttiioonn wweellllss ((PPWW--S5 aanndd PPWW-6-)6.). TThhee ttrraannssdduucceerrss wweerree pprrooggrraammmmeedd t0o rreeccoorrdd wwaatteerr lleevveell eelleevvaattiioonnss aattoonneeoorr ffiivvee--mmiinnuuttee iinntteerrvvaallssddeeppeennddiinnggoonn tthhee wweellll''ss pprrooxxiimmiittyy t(o PPWW--66 ((ii.ec.., cclloosseerr wweellllss sseett aatt oonnee--mmiinnuuttee iinntteerrvvaallss aanndd mmoorree ddiissttaanntt wweellllss sseett aatt ffiivvee--mmiinnuuttee iinntteerrvvaallss dduuee ttoo aannttiicciippaatteedd rreessppoonnssee ttiimmeess)).. OOnn MMaayy 22,, 22000066,, ddaattaa llooggggiinngg ccoommmmeenncceedd aanndd aatt 59::0000 aamm oonn MMaayy 44,, pprroodduuccttiioonn wweellll PPWW--66 wwaass tfuurmneedd ooffff. IItt rreemmaaiinneeddooffffffoorr apprporxoixmimataetellyy 2244 hhoouurrss uutnitill MMaayy 5 wwhheenn iitt wwaass ttuurnneedd oonn aaggaaiinn.. IItt rreemmaaiinneedd oonn ffoorr aapppprrooxxiimmaatteellyy 2244 hhoouursrs.. AAtt 99.:0000 aamm oonn MMaayy 66,, PPWW--66 wwaass tfuurmneedd ooffff aanndd rreemmaaiinneedd ooffff ffoorr tthhee rreessttoofftthhee ssttuuddyy ppeerriioodd wwhhiicchh eennddeedd MMaayy 88 aatt 11::0000 ppmro.. OOnn MMaayy 88,, tthhee ttrraannssdduucceerrss wweerree rreemmoovveedd ffrroomm tthhee wweellll.s. IItt iiss iimmppoorrttaanntt t0o nnoottee tthhaatt dduurriinngg tthhee ssttuuddyy ppeerriioodd ffrroomm MMaayy 22 t1o0 MMaayy 88,, 22000066 pprroodduuccttiioonn wweellll PPWW-5-5,, wwhhiicchh iiss rreellaattiivveellyy cclloossee ttoo wweellll PPWW=-66,, ccyycclleedd oonn aanndd ooffff nnuummeerroouuss tfiimmeess iinn rreessppoonnssee ttoo ppllaanntt wwaatteerr ddeemmaanndds.s. I11t wwaass ffoouunndd tthhaatt tthhee wwaatteer lleovveel iinn MMWW-1-144,, wwhhiicchh iiss cclloosseesstt 0to PPWW--66,, ddiidd nnoott cchhaanngge iinn rreessppoonnssee ttoo sshhuuttddoowwnn ooff PPWW-.6. IItt iiss ssuussppeecctteedd tthhaatt tthhee llaacckk ooff rreessppoonnssee iiss dduuee 1to0 aa ccllooggggeedd wweellll ssccrreeeenn.. TThhuuss, tthhee ttrraannssdduucceerr wwaass mmoovveedd ffrroomm MMWW--1144 ttoo MMWW--1177. AAsismimilialrarllaacckkooffrreessppoonnssee wwaass nnootteedd aatt wweellllss MMWW--44 aanndd MMWW--1122 aanndd itt iis ssuussppeecctteedd tthhaatt tthhee ccaauussee iiss cclloogggaeedd wweellll ssccrreeeennss oorr ccoollllaappsseedd wweellllss.. AAss ssuucchh,, 33MM ppllaannss 1to0 eevvaalluuaattee tteecchhnniiqquueess ffoorr rreehhaabbiilliittaattiinngg oor,, iiff nneecceessssaarryy,, rreeppllaacciinngg wells wells MW-4, MW-4, MW-12, MW-12, and and MW- MW- 114. TThhee rreeccoovveerryy aanndd ddrraawwddoowwnn ddaattaa ccoolllleecctteedd dduurriinngg tthhee hhyyddrraauulliicc ssttuuddyy wweerree uusseedd ttoo eessttiimmaattee tthhee eexxtteennttooffggrroouunnddwwaatteerr ccaappttuurree ffoorr pprroodduuccttiioonn wweellllss PPWW--55 aanndd PPWW-6-6.. TThhiiss eevvaalluuaattiioonn ccoonnssiisstteedd ooff ccoonnssttrnuccttiinngg aa ggrroouunnddwwaatteerr eelleevvaattiioonn ccoonnttoouurr mmaapp ffoorr ppuummppiinngg ccoonnddiittiioonnss uussiinngg wwaatteerr lleevveellss ccoolllleecctteedd iinn ssiittee mmoonniittoorr wweellllss oonn MMaayy 33,, 22000066.. TThhee ppuummppiinngg rraattess ffoorr pprroodduuccttiioonn wweellllss PPWW--55 aanndd PPWW--66 wweerree aapppprrooxxiimmaatteellyy 11440000 aanndd 553300 ggaalllloonnss ppeerr mmiinnuuttee ((ggppmm)),, rreessppeeccttiivveellyy.. GGrroouunnddwwaatteerr eelleevvaattiioonn mmeeaassuurreemmeennttss from pprroodduuccttiioonn wweellllss PPWW--55 aanndd PPWW--66 wweerree nnoott uusseedd tfoo ccoonnssttrruucctt tthhee ccoonnttoouurr mmaapp ssiinnccee hheeaadd lloossss aaccrroossss tthhee wweellll ssccrreeeenn aanndd ggrraavveell ppaacckk ccaauussee tthhee mmeeaassuurreedd wwaatteerr lleevveell iinn tthhee ppuummppiinngg wweellll ttoo bbee lloowweerr tthhaann tthhee wwaatteerr lleevveell iinn tthhee aaqquuiiffeerr iimmmmedeidaiatteellyy oouuttssiiddee tthhee ppuummppiinngg wweell.l. TTihiss pprroodduucceess aann eerrrroonneeoouussllyy llooww wwaatteerr lleevveell eelleevvaattiioonn wwhhiicchh ccaann ccaauussee Z:~FQLDI~.S.O-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc TTT Sas3-15 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 22116622..00005533 33MM_EENNVV_0000000033112299 S3MM_MMNNO011448833005544 capture zones to be overestimated. An appropriate water level elevation to use for production wells for contouring purposes was determined using the Theis analytical equation (Theis, 1935). Hydraulic parameters input into the Theis equation to calculate drawdown in a pumping well given a specific flow rate, were derived from a recent aquifer testing program performed on-site. A summal~ of the findings from the hydraulic study is presented in Section 4 of this report. The complete report was submitted to MPCA in November 2006 and is also presented in Appendix A of this Phase 2 Data Assessment Report. 33..33..77 EEaasstt aanndd WWeesstt CCoovveess As shown in Figure 3-3, the East and West Cove areas are surface water features adjacent to the Mississippi River and are located at the eastern and western ends of the Plant pprrooppeerrttyy.. TThhe EEaasstt CCoovve receiivves rreegionnaall surffaace wwaatteerr draiinnaagge aanndd ddiisscchhaarrggee wwaatteerr from the two NPDES-permitted discharges (cooling water and waste water treatment). The West Cove receives surface drainage from the Fire Training Area and the contractor storage yard to the east and north. From the west, surface drainage enters the west cove ffrroomm tthhee mmuunniicciippaall sseewwaaggee ttrreeaattmmeenntt ppllaanntt aarreeaa.. TThhee sseewwaaggee ttrreeaattmmeenntt ppllaanntt oouuttffaallll omens discharges directly to the Mississippi River. Objectives The obj ectives of Phase 2 activities at the East and West Coves were: To physically characterize the extent of the coves and sediments within the coves. To thither characterize the extent of FCs in the surface water and sediment of tthhee ccoovveess.. The assessment activities in the east and west coves were per~'ormed in September 2006. z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-16 22116622..00005544 33MM_EENNVV_0000000033113300 3M MN01483055 Physical Characterization Activites Physical Characterization Activities 3M provide dtd topographic ap of the sit including he Ext and West Cove 3M provided a detailed topographic map of the site including the East and West Coves hich wrs distinguished by opogapic contours. The boundaries wer ily verfid which were distinguished by topographic contours. The boundaries were visually verified iinn tthhee ffiieelldd bbyy WWEESSTTOONN ppeerrssoonnnneell aanndd iitt wwaass ddeecciiddeedd tthhaatt tthhee mmaappss aaccccuurraatteellyy rreefflleecctt planed nthe Phas2e FC Work Plan ws ct neces. tthhee bboouunnddaarriieess ooff tthhee ccoovveess.. TThheerreeffoorree,, aaddddiittiioonnaall ssuurrvveeyyiinngg ooff tthhee ccoovvee bboouunnddaarriieess aass planned in the Phase 2 FC Work Plan was not necessary. In scorn with he Phase 2 FC Wark Plan, ding the sediment sampling rogram, In accordance with the Phase 2 FC Work Plan, during the sediment sampling program, tits vers ake, slic oe nse of nanos or panty pind efforts were made to estimate the thickness of non-native or potentially impacted sediment schon, Polycarbonate bes were pres nf the sedimenbyt hd athe sediment in each cove. Polycarbonate tubes were pressed into the sediment by hand at the ssiixx PPhhaassee 22 ssaammpplliinngg llooccaattiioonnss. AA vviissuuaall ddeessccrriippttiioonn ooff tthhee rreeccoovveerreedd mmaatteerriiaall wwaass mmaaddee aanndd tthhee ddeepptthhoofftthhee sseeddiimmeenntt eennccoouunntteerreedd aatt eeaacchh ssaammpplliinngg ppooiinntt wwaass rreeccoorrddeedd.. LLooccaattiioonn otal posing sys (GPS) i ccoooorrddiinnaatteess wweerree rreeccoorrddeedd ffoorr eeaacchh ooff tthhee ssiixx sseeddiimmeenntt ccoorree llooccaattiioonnss uussiinngg aa hhaannddhheelldd global positioning system (GPS)unit. Sediment and Surface Water Sampling Sediment and Surface Water Sampling In dion to coring to ial dent the spi xin of sediment dposis In addition to coring to visually delineate the spatial extent of sediment deposits described above, subsempies were elected from sled se samples a locations in described above, subsamples were collected from selected core samples at locations in the We Cove and tos th Est Con for FC ays. The sampling loans the West Cove and locations in the East Cove for FC analyses. The sampling locations reshownin Firs 34 and 55 are shown in Figures 3-4 and 3-5. SSeeddiimmeenntt ssaammpplliinngg wwaass ppeerrffoorrmmeedd aatt tthhrreeee llooccaattiioonnss iinn tthhee ssmmaallll ((aapppprrooxxiimmaatteellyy oonnee cre) West Cove Six locations wr sampled inthe gr (aprosimarly wore) st acre) West Cove. Six locations were sampled in the larger (approximately two acres) East ceCove. A sediment core sample was als collected from the sent bank or dels 3 he A sediment core sample was also collected from the sediment bank or delta at the conten ofthe ast Cove dich nd he Missi River confluence ofthe East Cove discharge and the Mississippi River. dimen cores wee collects using poche bes with or cers to iii Sediment cores were collected using polycarbonate tubes with core catchers to minimize Joss of material. Sample clon and ending ws performed in scorns with the loss of material. Sample collection and handling was perfomaed in accordance with the sediment sampling SOP conned in he hse 2 FC Work Pl. Sapling mrt om sediment sampling SOP contained in the Phase 2 FC Work Plan. Sampling intervals from ccoorreess oobbttaaiinneedd aatt eeaacchh ooff tthhee sseelleecctteedd llooccaattiioonnss iinncclluuddeedd ssuubbssaammpplleess ffrroomm tthhee zzeerroo ttoo 66 re z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-17 33MM_EENNVV_0000000033113311 swmnoonss 3M MN01483056 22116622..00005555 inch sediment horizon and the 6 inch horizon above the native alluvial material underlying recent deposits. This was the interval designed to sample non-native deposition material. In instances where sediment thickness was greater than 3 feet, an aaddddiittiioonnaall 66 iinncchh ssuubbssaammppllee wwaass ccoolllleecctteedd ffrroomm tthhee mmiiddddllee ooff tthhee sseeddiimmeenntt ccoolluummnn.. AA subset of the core sampling locations also included subsamples from native alluvium at the bottom of the core based on field conditions and observations of sediment ssttrraattiiggrraapphhyy.. Surface water samples were collected from each cove at the inlet and outlet areas to determine whether FC concentrations increase across the coves due to adsorptiondesorption mechanisms. At each location, a discrete water sample was collected at the water surface, 20% and 80% of the total depth. At locations where the water depth was lleessss tthhaann ttwwoo ffeeeett,, aa ssiinnggllee ddeepptthh ssaammppllee ((6600%% ddeepptthh)) wwaass ccoolllleecctteedd.. Sediment and surl~ace water samples were analyzed for the 12 FC compounds at Exygen Research. In addition to the FC analyses, field measurements were taken at each sample location for temperature, pH, dissolved oxygen (DO), conductivity and water velocity. 3.3.8 Mississippi River TThhee MMisisssiissssiippppii RRiivveerr iiss tthhee mmaaiinn ssuurrffaaccee wwaatteerr bbooddyy aalloonngg tthhee ssoouutthheerrnn bboouunnddaarryy ooftf thhee site. The fiver receives surface water discharge from both the East and West Coves and groundwater discharge from the eastern part of the plant. Groundwater is being captured in the western part of the plant by the plant production wells (PW-5 and PW-6). OObbjejecctitivveess. TThhee oobbjjeeccttiivveess ooff PPhhaassee 22 aaccttiivviittiieess aatt tthhee MMiissssiissssiippppii RRiivveerr wweerree:: To assess possible groundwater discharge from the plant site through bottom sediments and into the river. To further assess the presence or absence of FCs in surface water and sediment in the river at locations upstream, adjacent, and down stream of the Cottage Grove Site and extending downstream to Lake Pepin. z :~F OLDI~.S .0-9' 3m-c ollage grove'Yhase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-18 22116622..00005566 33MM_EENNVV_0000000033113322 3M MN01483057 + To assess the spatial disuibution of FCs in surface water across the To assess the spatial distribution of FCs in surface water across the MMisisssiissssiippppii RRiivveerr iinn tthhee iimmmmeeddiiaattee vviicciinniittyy ooff tthhee CCoottttaaggee GGrroovvee SSiittee.. TThhee aasssseessssmmeenntt aacctiivvittieess iinn tthhee MMisisssiissssiippppii RRiivveerr wweerree ppeerrffoorrmmeedd iinn SSeepptteemmbbeerr 22000066. 33..33..88..11 PPoorreewwaatteerr PpPooosrrseeiwwbalateteegrrrowwuaanssdwiiaddteenentrtiiffdiiieesddchaaassrgppeaaarrtt thooff tthshuiissrfaaacssesseewssasstmmeerengntrt oppurrnoodggwrraaatmmeraassinaatermmfeaeacaennssat the bottom ttoo eevvaalluuaattee pofostshibeleMigsrsoisusnidpwpiateRirvderis.chPaorgreewaatetrheissuwrafatceer wcoantetra/ignreodunidnwtahteerpoinretesrfoafceiavtrthseebdoimtteonmt wohfitchhe MisissbieslsiipevpeidRitov.err.ePproerseewntategrroisunwdwaatetrerconditasicnheadrgiinngtheuppwoarreds otfo ritvheer sreidveimrbeendt wPohriecuhatiesr bsaemlipelveesd artoe breelpirevseednttogbroeumnodrweatreerprdesisecnhtaatrgivinegofuFpCwacrodncetontrtahteionrisveartbetdhe. Psrooreuwndawtaetresfasmurpflesscearaetebreliinetveerdfacteo btheanmsourrefarceepwreasteenrtastaivmpeleosf dFuCe ctoondicleunttiroantions at the groundwater/surface water interface than surface water samples due to dilution. PPoorreewwaatteerr Sammpplliinng AAss sshhoowwnn iinn FFiigguurree 33-66,, ppoorreewwaatteerr ssaammpplleess wweerree ccoolllleecctteedd aatt aapppprrooxxiimmaatteellyy 4433 llooccaattiioonnss iinn tthhee MMisisssiissssiippppii RRiivveerr aalloonngg tthhee ffaacciilliittyy sshhoorreelliinnee ttoo aasssseessss ppoossssiibbllee ggrroouunnddwwaatteerr ddiisscchhaarrggee tthhrroouugghh bboottttoomm sseeddiimmeennttss ninttoo tthhee rriivveerr.. TThhee aannaallyyttiiccaall rreessuullttss ffrroomm tthheessee along the entire facility propery adjacent o the rive. ppoorreewwaatteerr ssaammpplleess aarree uusseedd ttoo cchhaarraacctteerriizzee tthhee nnaattuurreeooff ggrroouunnddwwaatteerr ddiisscchhaarrggee ppaatthhwwaayy along the entire facility property adjacent to the river. AAss ddeessccrriibbeedd iinn SSuubbsseeccttiioonn 33..33..66,, tthhee ppuummppiinngg ooff pprroodduuccttiioonn wweellllss PPWW--S5 aanndd PPWW--66 iinntteerrcceeppttss tthhee ffllooww ooff ggrroouunnddwwaatteerr iinnttoo tthhee rriivveerr.. TThhee eeffffeecctt ooff tthheessee ppuummppiinngg wweellllss Sshhoouulldd bbee rreefflleecctteedd bbyy tthhee ppoorerwtaeterrrreessuullttss wwiitthhiinn tthhee ccaappttuurree zzoonneeoofftthhee wweellllss. AAss sshhoowwnn iinn FFiigguurree 33--66,, ppoorreewwaatteerr ssaammpplliinngg llooccaattiioonnss iinncclluuddee 2255 eeqquuaallllyy ssppaacceedd ssttaattiioonnss laloongnaa ttrraannsseecctt aapppprrooxxiimmaatteellyy 110000 ffeecett ffrroomm aanndd ppaarraallleell ttoo tthhee sshhoorreelliinnee.. IInn addon addition, ssiixx locationsa distances of 25 1, 50 1, 200 , 300 , 400 , and 500 t from the shorsine lwoecraetioesntsabaltidshisetdanslcoesngoefa2c5h Iotf, t5h0reIet,r2a0n0sefctt,s3o0r0iefrt,te4d00peIrtp,eannddic5ul0a0rfttoftrohemshthoreelsihnoereline were established along each of three transects oriented perpendicular to the shoreline. 0.00S-nch sloted screen and sufficient riser to extend bove the surface of the ater PPoorreewwaatteerr ssaammpplleess wweerree ccoolllleecctteedd uussiinngg ssttaaiinnlleessss sstteeeell ssaammpplliinngg pprroobbeess wwiitthh 00..55 ffeeeett ooff 0.005-inch slotted screen and sufficient riser to extend above the surface of the water. intercepts a depth of 0.5 fee 0 1.0 feet below the topofsediment. The probe was purged TThhee pprroobbeess wweerree ddrriivveenn aapppprrooxxiimmaatteellyy oonnee ffoooott iinnttoo tthhee sseeddiimmeenntt ssoo tthhaatt tthhee ssccrreeeenn intercepts a depth of 0.5 feet to 1.0 feet below the top of sediment. The probe was purged Confidential - 3M Insurance Documents rr . z:~FC~LDI~.S.0-9'3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc 33--1199 Confdential- 3M Insurance Documents M3M_ENEVN_V0000000033113333 W3M_MNMONT04184833005588 22116622..00005577 ooff wwaatteerr uussiinngg aa ppeerriissttalltiicc ppuummpp.. TThhee ttoottaall vvoolluummee ooff wwaatteerr rreemmoovveedd wwaass rreeccoorrddeedd aanndd tthhee sstuattiioonn aalllloowweedd ttoo rreecchhaarrggee.. OOnnccee tthhee pprroobbeess ssuuffffiicciieennttllyy rreecchhaarrggeedd,, tthheeyy wweerree ssaammpplleedd uussiinngg tthhee ppeerriissttalltiicc ppuumr.p. PPoorreewwaatteerr ssaammpplleess wweerree aannaallyyzzeedd ffoorr tthhee 1122 FFCC ccoommppoouunnddss bbyy EExxyysggeenn RReesseeaarrcchh.. IInn conductivity and velocity at th imeofsampling. aaddddiittiioonn ttoo tthhee FFCC aannaallyysseess,, ffiieelldd mmeeaassuurreemmeennttss wweerree ttaakkeenn ffoorr tteemmppeerraattuurree,, ppiHl,, DDOO,, conductivity and velocity at the time of sampling. 53..33. 88.22 SSuurrffaaccee WWaatteerr aanndd SSeeddiimmeenntt PPoorreewwaatteerr SSaammpplliinngg LLooccaattiioonnss SSuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess wweerree ccoo--llooccaatteeddwwitithhtthhee ppoorreewwaatteerr ssaammppleless.. SSuurrffaaccee wwaatteerr ssaammpplliinngg wwaass ccoonndduucctteedd iinn aaccccoorrddaannccee wwiitthh tthhee SSOOPP pprroovviiddeedd iinn tthhee PPhhaassee 22 FFCC Work Plan with th folowing modification. At each of the 43 locations, a discrete water WsaomprklePlwaanswciotlhltchteedfoaltlo2w0in%gamndod8i0fi%caotfiotnh.eAot teaachdeoptfhthuesi4n3galocpaetriiosntsal,taicdpisucrretefowraFteCr asnaamlypslees.waFsorcoellxeacmtpedlea,t a2t0%a saanmdpl8e0%locoaftithoen twohtaelredetphteh wuasitnegr adeppetrhistiaslti1cfpoutm, psafomrplFeCs awnoaullydsesb.e Fcolrleecxtaemd palte,deapttahssaomf p0l.e2 lfotcaatnidon0.w8hfetrebetlhoewwwaatteerrdseuprtfhaceis. 1Afosoitn,glseamdeppltehs wSaomuplldeb(e60c%olldeecpttehd) aatsdecplthlsctoefd0i.2fthfte awnatder0.d8epftthbewlaosw-lewssattehransutrwfaocfee. tAIsninadgdleitidoenpttho tshaempFleC(6a0n%alydseepst,h)fwiealsd comleleacstuerdemifetnhteswwateerredetpatkhewn asfolresstethmpaenrattwuoref,eet.pHIn, adDdOi,tionantod tchoenduFcCtiviatnyalaytstehse, tfiimeeldofsmameapsluirnegments were taken for temperature, pH, DO, and conductivity at the time of sampling. SSeeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd uussiinngg aa ssttaaiinnlleessss ssteeesl ccoorrerr wwiitthh aa ppoollyyccaarrbboonnaattee ssaammppllee ttuubbee.. DDiissccrreettee sseddiimmeenntt ssaammpplleess wseerree ccoolllelcsttedd ffrroomm tthhee 00--1100 ccmm aanndd 1100--2200 ccmm ddeepptthh iinntteerrvvaallssaat eeaacchh ooff tthhee 4433 ppoorreewvaatteer llooccaattiioonnss.. FFiivvee llooccaattiioonnss wweerree sseelleecctteedd ffoorr ssaammpplliinngg ddeeceppeerr sseeddiimmeenntt ssaammpplleess ((ii..e..., 5500--6600 cCml)n.). SSeeddiimmeenntt ssaammpplliinngg pprroocceedduurreess aarree described in dealin the sediment sampling SOP provided in the Phase 2 FC Work Plan described in detail in the sediment sampling SOP provided in the Phase 2 FC Work Plan. SSuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess wweerree aannaallyyzzeedd ffoor tthhee 1122 FFCC ccoommppoouunnddss aatt tthhee EExxyyggeenn RReesseeaarrcchh LLaabboorraattoorryy. LLoonnggiittuuddiinnaall SSeerriieess SSaammpplliinngg LLooccaattiioonnss. AAss sshhoowwnn iinn FFiigguurree 3,3-7, ssuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd ffrroomm tthhee MMisisssiissssiippppii RRiivveerr nnaavviiggaattiioonnaall cchhaannnneell ssttaarrttiinngg aatt aa llooccaattiioonn ssiixx mmiilleess uuppssttrreeaamm ffrroomm tthhee er z :~F C~LDI~S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc i. CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-20 33MM_EENNVV_0000000033113344 W3M_MNMON104184833005599 22116622..00005588 facility (river mile [RM] 824) downstream to the headwaters of Lake Pepin (RM 784). These sample locations are representative of an approximately 40-mile section of the Mississippi River. At the farthest downstream sampling area adjacent to RM 784, three llooccaattiioonnss wweerree ssaammpplleedd aaccrroossss tthhee wwiiddtthh ooff tthhee rriivveerr ttoo cchhaarraacctteerriizzee ppootteennttiiaall eeffffeeccttss ooff sediment deposition in this area at Lake Pepin. Surface water sampling was conducted in accordance with the SOP provided in the Phase 2 FC Work Plan with the following modification. At each of" the 17 locations, a discrete water sample was collected using a peristaltic pump at 20% and 80% of the total depth. These samples were composited into a single sample for FC analyses. Field measurements were taken for temperature, pH, DO, and conductivity at the time of sampling. Water velocity data was also recorded for each sampling depth at each longitudinal sampling location. A petite ponar grab sample of surface sediment was collected at each of the 17 longitudinal series sampling locations for FC analysis with the exception of four locations at the headwaters of Lake Pepin (south of Red Wing). At these locations (RM 784 and 778855aa.,bb aanndd cc)) sseeddiimmeenntt ccoorreess wweerree ccoolllleecctteeddttoo aa ddeepptthhooff 33 ffeeeett iinnttoo tthhee sseeddiimmeennt.t. TThhrreeee ddiissccrreettee ssaammpplleess wweerree ccoolllleecctteedd ffrroomm eeaacchh ccoorree ((ttoopp,, mmiiddddllee aanndd bboottttoomm).). SSuurrffaaccee wwaatteerr and sediment samples were analyzed for the 12 FC compounds by Exygen Research. TTrraannsseecctt SSaammpplliinngg LLooccaattiioonnss Surface water and sediment samples were also collected at three transect locations perpendicular to the flow direction across the width of the Mississippi River: upstream of tthhee ppllaanntt ((XXSS--11)),, ddoowwnnssttrreeaamm ooff tthhee EEaasstt CCoovvee bbuutt uuppssttrreeaammooff tthhee ddaamm aatt HHaassttiinnggss ((XXSS-- 2), and downstream of the Hastings dam (XS-3) as shown in Figure 3-8. The transects were aligned perpendicular to flow. Upstream of the Hastings dam, the two transects FA consisted of five equally spaced sampling locations (a through e) spanning the river at both locations. The river at the downstream location below the dam is more narrow than the upstream locations and sampling was performed at three locations (a through c) along this transect. A total of 13 locations were sampled along the three transects. z :~F C~LDI~.S .0-9' 3tn-c ottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-21 22116622..00005599 33MM_EENNVV_0000000033113355 3M MN01483060 SSuurrffaaccee wwaatteerr ssaammpplliinngg wwaass ccoonndduucctteedd iinn aaccccoorrddaannccee wwiitthh tthhee SSOOPP pprroovviiddeedd iinn tthhee PPhhaassee 22 FFCC WWoorrkk PPllaann wwiitthh tthhee foolllloowwiinngg mmoodidfiificceattiioonn.. AAtt eeaacchh llooccaattiioonn,, aa ddiissccrreettee wwaatteerr ssaammppllee wwaass ccoolllleecctteedd uussiinngg aa ppeerriissttaallttiicc ppuummpp aatt 2200%% aanndd 8800%% ooff tthhee ttoottaall ddeepptthh.. AAtt tthhee mmiiddddllee ttrraannsseecctt ((XXSS--22)) aann aaddddiittiioonnaall ssaammppllee wwaass ccoolllleecctteedd ffrroomm tthhee wwaatteerr ssuurrffaaccee aatt tthhee ffiivvee llooccaattiioonnss.. IInn aaddddiittiioonn ttoo tthhee FFCC aannaallyysseess,, ffiieelldd mmeeaassuurreemmeennttss wweerree ftaakkeenn ffoorr tteemmppeerraattuurree,, ppHH,, DDOO,, aanndd ccoonndduuccitivviittyy aatt tthhee ttiimmeeooffssaammplpilningg.. W Waatteerr vveelloocciittyy ddaattaa wwaass aallssoo rreeccoorrddeeddffoorrceaacchh ssaammpplliinngg ddeepptthh aatt ceaacchh ttrraannsseecctt ssaammpplliinngg llooccaattiioonn.. AA ppeettiittee ppoonnaarr ggrraabb ssaammppllee ooff ssuurrffaaccee sseeddiimmeenntt wwaass ccoolllleecctteedd aatt eeaacchh ooff tthhee 1133 ssaammpplliinngg llooccaattiioonnss ffoorr FFCC aannaallyyssiiss.. SSuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess wweerree aannaallyyzzeedd ffoorr tthhee 1122 FFCC ccoommppoounudnsbdbysy EExxyyggeenn RReesseeaarrcchh. 33.44 MMPPCCAA SSPPLLIITT SSAAMMPPLLEESS DDuurriinngg tthhee PPhhaassee 22 SSaammpplliinngg PPrrooggrraamm iinn SSeepptteemmbbeerr 22000066,, tthhee MMPPCCAA rreeqquueesstteedd ssppeeccififiicc: ssaammpplleess bbee ssppilitt ffoorr tthheeiirr aannaallyyssisis.. WWaatteerr ssaammppllee bboottttlleess wweerree ffiilllleedd bbyy W WEESSTTOONN aatt tthhee ssaammee ttiimmee aass tthhee 33MM ssaammppleless.. SSeeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd eeiitthheerr wwiitthhaa ppeettiittee ppoonnaarr ssaammpplleerr oorr ppoollyyccaarrbboonnaattee ttuubbeess iinn aa sseeddiimmeenntt ccoorriinngg ddeevviiccee.. TThhee ssaammpplleess wweerree sspplliitt iinn eqquuaall vvoolluummeess aanndd ppllaacceedd iinn ssaammppllee jjaarrss pprroovviiddeedd bbyy MMPPCCAA.. TTaabbllee 33--44 ssuummmmarairizzeess tthhee ssaammpplleess aanndd llooccaattiioonnss sspplliitt wwiitthh MMPPCCAA. co cmc z :~FC~LDI~.S .0-9' 3tn-cottage grove'hase 2 FC Data A~sesslnmt RepolrWinal Phase 2 Report.doc i. CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-22 22116622..00006600 33MM_EENNVV_0000000303113366. 33MM_MMNNO011448833006611 * i:r s Re U LESFNA "a pal" Ten 5 I i? ! \" 5 ,& Le . fon A re Fl wm WERT Lars : : 13 ) ! 9 % ' d / =u We So ed a: [2 : : TH : 5 Eh 8 EH | EH g HE LE A J Lonfitgntia): 3M Jiedighoc Poul Te aed yo] 5s 22116622..00006611 i 3 SLING 1483063 3M MN014830~,~" -1 : os by CL a lAl - a i; ch =e [ Bh ae LyTe hillh; NS | E, oier 3 id - =Ewe : X ses vases =od ed 5 | t .~ & 3 . y 5 Lewd i Legend: Phase 2 Soil Sampling I~ocation 0 ---- Previous SB Sampling I~ocation CORS4METnsurTanlie -- |2O wm 0 62.5 125 a? ~Feet Pn Map Source. BEEFBR, U S Departmenl o Agricu#ute, Fam~ Services Agency, FIGURE 3-2 rp HEes FIRE TRAINING AREA sof SEIEANNOMEN SOIL SAMPLING LOCATIONS oA GROVK S COTTAGE GROVE SITE Sw_Eny_00003138 3M ENV 00003138 D~itat Orthorect~fied Images (DO3), Minnesota, 2063 File: k\FswcB~roj6,Cottage_Grove\mxdskFire._trainir~g_area dec ~ocs.mxd, 27oduno07 14:11, rcksc Su_Norssoss 3M MN01483063 22116622..00006622 r Fee lA gBe S TRT E IGpT E P[IeRT , EE ASTT5, S A R fE SR o ERSAhe BELT N oh Ad ae vf ria ! Ta 1 spon aEE \ fPi S aeC s E nOeETS Ro EOHl oh ri TE A AACEawlge PEL]. | he 2 W WAe R e 2Bhaaa E s o S Ce RY LR Fakoa dN leo ya ds eaJd Y Se 2 Ws Eon je = SE FoSWEENTSe 8a i gah l B iSeol m fEeT Seadd | Balaniy 7 ey oY iE! 18g HLh E : | EilYl 2 /i Tan A EET A sine i AA Ty A) HCoo d) eTeag Lmee Bn NTE LR T aA Hx | 2% als WTaY TL RIE ED L SYFee Ss TE 7 # = AE To .. temle. bw i i = Neal SV EL 5NY3 p A e 3Rt SAI = || sper AAnRES VenerTTelT Jed Sy fi , LI ConfiTdeiatall 30 EIN InsuranCdegDocumeR dtga~~ deJ I 4 Jadl ooooaras /5 \ in a ett pe] NEw aivJorhiasoss 3M MN01483064 22116622..00006633 +i, VE r { ' x b, byin a 3 Et : pe - dies Rol 4 of - { . %, & Ay L CSE 1 Aa gH B- ae niED ~S y B. pu ae LY ied ANg Ld Ty CRTTan et ae RL 3 g. : aa n : Leg > Legend: N West Cove 1 Acre -- ou ep ~ Phase 1 Sampliug Locations 8 swine vmsetmersmieg evan| em /~ Surface Water/Sediment Sa~npling Location 100 200 t-e400 Feet CCh~nfnifdie~nt~ial~k=@ 8M-itn~susraunra8n TEENIE ~ A SSeidmimoennt SSuamrpplliinnggLoLcoactaitoionn as soon Map Source. U S Departrnenl of Agricu#ute, Fam~ Services Agency, D~jitat Orthorect~fied Images (DO,j, Minnesota, 2063 ~Co~age_Grove~mxds~west cove dec Io~ m~d, 27 Jua D7 4:13, ricksc 22116622..00006644 SAMPLeINSG LCOCoAuTIONS FIGURE 3-4 SAMPLING LOCATIONS WEST COVE 3M_ENV_00003140 CCOOTTRAGRE GORUOVIE vSITeE 3M ENV 00003140 SMLMNO1453065 3M MN01483065 = be Re py i >3 & b, yp TY J | NE BE A 8 =5 a - of 3 g 5: : " - 4 ri a 3 Ti bo a WINS ca }A Eg 3 . A _-- ha he A8 : os Nig, 5 hb ErSAora RE % Rd LTR peERal WEN se . aie es eRte AEE a PD RL A Legs iN Legend: F, gL~t Cove 2 Acres ED ere [~ Phase 1 Sampling location ConfsiedmeenvtaimatmticmmSesherIingsiusrnainn6 /~ Surface Water/Sediment Sampling Location FE =. 75 150 300 Feet for -- Map Source. TIBCUMENE wr. U S Departmenl of Agricu#ute, Farm Services Agency, D~itat Orthorect~fied Images (DO3), Minnesota, 2063 RTT 2a a0 FIGURE 3-5 soi non SAMPLING LOCATIONS EAST COVE COTTAGE ROVESITE COTTAGE GROVE SITE 33MM_EENNVV_0000000033114411 aMovaga06 3M MN01483066 22116622..00006655 =A od 8 rLeip Ea . Ra of TE 2162.0066 i| E. IN = : 3M MN01483067 FL rnte i Te A YpNEEIIT R ESR LRA el F{eBSa LNNSSEgSF eChord, TSMT PIC Loy hee Ms 2 Er dE 3 Eon k 4 SR | Cp Sena Sp Tf AR Spry AE He 30 IY sol ZEA deca CATT ANE AEN RETS SN ESHSC FEAA #eO S F Sz A ih G Hee op fle Ie sae Jee CETL TC oT Py SNSn G Sd oyHS ha TNepr p "elf SS r e e d orB J i Eo4y al 3i 22116622..00006677 3M MN01483068 Cares a al L&E RE | qe Dram Ead !ElAf |E S =P ginAZPSL dN 4) a Ul 5 ) h th 7 by oSfLE l SA A = Ig 3 2] # ABa n UD Ales i + 8 AE AR ae Gidt AES Ei 5 Be H ap# e c0 hip nf ; a= Lam: ah \ TTaokle |fAeNTtE AUER Rem EEE EEE eyJ Vi 3 FE Be faro "pozh] Hp OEE e | ce ge (1: ] Z8R pr a$s WgiF 3M MN01483069 22116622..0000668 ! I I I |ale i lel Lie i 2 i EHHABE g 2H:i8e3 S338 [8 ii P53 2 ET 8 [-o|ndafoln lHeiReAtRE] 1 Ti e| l loin] l+of=lel Hi |e] Hd I H ziili iii i ii rd SL | HL Po 2EH e EHEHs EERs E Ee EE sEEE iE] [EiE|EiE] Eig Eig |ElE|E le] EE] Pi odi 3 i HBelHellEelEMel|Hel2He2l5Hs||EEE1EHG21E15 E2IEEE]cHcEH IE|88]8)E|2]E8EE @ SEE EE a]5| FE]: od CCoonfnifddeennttiiaall ~- 33MM IInnssuurraannccee DDooccuummeennttss 33MM_EENNVV_0000000033114455 aw_otasaoro 3M MN01483070 22116622..00006699 TTaabbllee 33:-22 MMoonniittoorriinngg WWeellll CCoonnssttrruuccttiioonn DDeettaaiillss CCoottttaaggee GGrroovvee SSiittee warm Webnet|| aDebp Deptihoio0Water Diame|er|Schencdomeyna BSaernvcned(O510 Well ID Pwr--Te----or---- wm ---- 5 | MW-la Ta 5 wor wi 5 MW_2~ a ws 4 : 200 s 1WW-3 wa | 2 oss x0 v MV.4a ws| wr we ` eno a MW-5 wwe| 2 in v wiv 5 MW4;" Wr i ose sor se o MVq-7 ws ine Gis weno MVq-8 Svs ose a + = BE) 1WCq-9 Reported Well Depth (ft bgs) 200 192 210 200 210 219 146 173 104 Measured Well Depth (ft btoc) 92.64 Depth to Water (ft btoc) 67.71 92 85.91 196.75 99.4 133.2 10825 2(i) 8.7 51.57 103.2 Dryu 140.24 55.07 172.45 65.45 107.95 47.17 Well l}iameter (in) 6 6 6 6 6 6 6 6 4 Open Borehole / Completed as Open Screened Interval (ft bgs) Borehole (0) or Screened (S) NA O 53-192 O 57-210 O 75-200 O 36-210 O 60-219 O 51.5-146 O 51.5-173 O NA NA a Ea Tos 7 Tom < MV-10 237 241.5 93.73 8 198-237 O MV- 11 200 186.6 102.9 4 180-200 O was TT 5 En 7 Ts 5 1VIW-12 141 141.03 93.63 4 122-141 S MV-13 134 134 92.03 4 114-134 S MV-14 64 59 26.85 4 44-64 S Ca ow ow T = Ea MV-15 186 186.54 96.08 4 NA NA we i oir wn : = w MV-16 140 141.1 93.78 4 NA NA MMVwa- 1r7 |r 112 111443.366 775.228 a4 2 92-1212 sS ws 2 Go : on 5 MV-18 92 93.2 69.07 4 71-91 S Sw oa 5 : ow 5 MV-19 120 120 52.33 4 NA NA am Sie S57 3 ws + MW-101 100 101.9 94.87 2 90-100 S MVq-102 96 9,1.67 91.97 2 86 96 S ow w srs 5 ww 5 MW-103 86 86 80.38 2 78-88 S MW-104 88 88 81.54 2 78-88 S MVq-105 96.5 96.5 89.94 2 86.5-96.5 S Sw = w= 5 wor 5 MVq-106 95 95 886 2 85-95 8 swan os as ws wes 5 MW-107 9l .5 91.5 85.56 2 81.5-91.5 S wos| ws |e ow Tw MVq-108 103.5 103.5 96.88 2 93.5-103.5 S wos es ws 7 Ts 5 MW-109 46.5 46.5 433 2 36.5-46.5 S MW-I Ill 110 110 94.86 2 100-110 S PZ-14 100 187.71 64.26 2 NA S EE -------- "Measured depths are significantly shallower than previously recorded total depths s~ggesting borehole collapse. At MW-6, a s~naple could not be Slot vec ac cme we collected. bWell w~s dry due to obstruction in borehole. NA - Not ax,~lable. fonplain fi bgs feet below gound surface. fl bt~c tEet below tnp of ca~ing in - inches 332 3-32 Confidential 3M-meurance-DoeUMEents msmms 3M_ENV_00003146-= aW_MNot4830Tt 3M MN01483071 22116622..00007700 TTaabbllee 33-33 GGrroouunnddwwaatteerr SSaammpplliinngg SSuummmmaarryy CCoottttaaggee GGrroovvee SSiittee Sampling | WelDph | Dpto | Sampling Loction_| bz | Waterton | Location eros wn MW-103 wine sts MW-104 wns | es wes MW-105 ios ws wx MW-106 mor | ors sco MW-107 ms | ess oe MW-108 wets | ass an MW-109 Well Depth (ft bgs) 86 88 96.5 95 91.5 103.5 46.5 Depth to Water (ft toc) 80.70 81.95 90.65 89.32 86.40 97.98 43.37 Var | Well Diameter | Diameter che) (inches) 22 22 22 22 22 22 22 VVPoaalrungmeae | (Psuartgieodn| 35 | (gallons) 53.5 | 33s | 33.5 | s3 | 33 | 23 | 2 DateDate Sampled Sampled wea 9/8/2006 ama 9/8/2006 omnes 9/8/2006 amacoe 9/8/2006 amas 9/8/2006 amacee 9/7/2006 emacs 9/7/2006 MW-110 110 96.16 0 totbow rum src ft bgs - feet below ground surface tc astbaowotf coasipng ft btoc - feet below top of casing 2 7 9/7/2006 333-33 CCoonnffdiednetniatl--i33aMMl IInnssuurraannccee DDooccuummeennttss Z:\FOLDERS 0-9\3m-cottage grove\Phase 2 FC Data Assessment Repod\Figures-Tables\Section 3 Figures& Tables\T3-03_GW_Sarnp_Surnrnary.;ds 22116622..00007711 33MM__EENNVV__0O000000331144677/29/2007 W3M_MMoNt041s4383007722 Table 3-4 SSaammCpopltleetssagSSepplGilitrt owwviitethhSiMMtPPe CCAA Cottage Grove Site [sumprpc TsompteLocation[| Sampte umber[comments] Sample [we Tcovnvm|wamwe Type Sample Location Sample Number CGMN-IW-MRIW06 Comments [won IW-6 IW-gB cCGoMNm-IWv-MaRIWw09mb |riwon [wo IW-10 |cCoGmMmNv-IaWw-MaRrIvWi1e0 [| [wenIWs-13 [cCoGmMvN-aIWw-MmRrIWw1s3 [1 Porcwatcr [owerIWi-14nB --TcoCmGMnNa-wIWm-MrRaIwWi14nb [| [wIr W-17 ]cCoGmMvN-aIWw-MaRrIWw1e7 [| [weiIWs-1s9B |cCoGmMnN-aIWw-mMrRaIWo1n9b || [woIWo-20 |cCoGmMmNv-IW aw-MaRmIWw2n0 [| [waIWs -25 |cCoGMNm-IWv-MiRIWw25 |arwas 1 [we IW-6 TcCGoMNm-SDu-MnRI~sV0o61 | mmom0t-1oo0ecmmst| [woIWn -9B cCGoMNm-SnD-MsRIWp9bm1 |rwo0--1ot0occnmn t| [wo comvsovmwior| otoem | IW-10 CGMN-SD-MRI~V 101 0-10 cm [wes comvsoa|vmowveinsi| PPoorreewwaatteerr SSeeddiimmeenntt IW-13 IW-14B CGMN-SD-MRIW 131 CGMN-SD-MRIW 14b 1 0-10 cm 0-10 cm IW-17 CGMN-SD-MRIW 171 0-10 cm ae IW-19B [wa |counsom|romtwoeom r| IW-20 EE [was covsov|mwoiaoesm i| IW-25 CGMN-SD-MRIW 19b 1 CGMN-SD-MRIW201 CGMN-SD-MRIW251 0-10 cm 0-10 cm 0-10 cln XS-2A CGMN-SW-MRXS02a0 Water Surface SSuurafacceeWWataeterrTTroanssectt XS-2B XS-2C CGMN-SW-MRXS02b0 CGMN-SW-MRXS02c0 Water Surface Water Surface XS-2D CGMN-SW-MRXS02d0 Water Surface -- East Cove Sediment -- 1 East Cove Sediment XS-2E EC-6 CGMN-SW-MRXS02e0 Water Surface CGMN-SD-EC067 top 6" of sed. [ees |comnsp|eboctoomeosfscsa | EC-9 EC-5 CGMN-SD-EC097 CGMN-SD-EC059 top 6" of sed. bottom 6" of sed. EC-10 CGMN-SD-EC 109 bottom 6" of sed. -- ECD-1 CGMN-SD-ECD018 bottom 6" 1 of sed. East Cove Surface Water EC-04 EC-11 CGMN-SW-EC040 CGMN-SW-EC110 Water Surface Water Surface z :~F OLDI~S .0-9' 3m-c ollage grove'~Zhase 2 FC Data A~sesstnmt ReportWinal Phase 2 Report.dec CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss3-34 22116622..00007722 33MM_EENNVV_0000000033114488 3M MN01483073 4. RREESSUULLTTSS OOFF TTHHEE AASSSSEESSSSMMEENNTT = TThhrroouugghhoouutt tthiiss ddooccuummeenntt,, rreeffeerreenncceess aarree mmaaddee oto PPhhaasse 1| rreessuullttss aass nneecceessssaarryy ftoo pprroovviiddee aa mmoorree ccoommpplleettee uunnddeerrssttaannddiinnggooff tthhee aasssseessssmmeenntt ddaattaa aanndd ggrroouunnddwwaatteerr ppaatthhwwaayyss.. TThhee ccoommpplleettee pprreesseennttaattiioonn ooff PPhhaassee 11 iinnffoorrmmaattiioonn iiss pprroovviiddeedd iinn tthhee FFCC DDaattaa AAsssseessssmmeenntt Report, (WESTON, April 2006), A summary ofthe Phase 1 field sciiies and results is Report, (WESTON, April 2006). A summary of the Phase 1 field activities and results is presented in Subsection 3.1 presented in Subsection 3.1. TThhee aannaallyyttiiccaall ddaattaa pprreesseenntteedd iinn tthhee ffoolllloowwiinngg ssuubbsseeccttiioonnss iiss oorrggaanniizzeedd ttoo ffaacciilliittaattee aa ccoommppaarriissoonn ooff" tthhee ddaattaa aanndd ttoo bbee ccoonnssiisstteenntt wwiitthh ddaattaa pprreesseennttaattiioonn iinn tthhee AApprriill 22(030066 FFCC DDaattaa AAsssseessssmmeenntt RReepporotr.t. IInn PPhhaassee 11,, tthhee rreessuullttssoofef aeacchh ooff tthhee ffoouurr FFCCss aannaallyytteess ((PPFFBBSS,, PPDFFaHHtSS,A, sPPsFFeOsOSsS,m,enaatnnddRePPpoFFrOOt.AA))Thwwusee,rreethsseuummPmhmaasraeriizz2eeddFCiinnanddaaalttyaatittcaaabbllleedssaapprresessueemnnmtteaeddryiinnabtthhleeestteepxxrtteosofeftntthheede DinattaheAtsesxesosfmtehnist Rreeppoorrtt.inTchluusd,ethPeFBPSh,asPeH2SF,CPaRnOaSly,tiacnadl dPaFtaOAs.umPmFaDrAy tiasbalelsopirnecselnudteedd ian5 rthe etceexnttocfothmipsoruenpdortofinicnltuedreesPt FBASc,oPmFplHeSt,ePdFrOaS,suanmdmaPrFyOAta.blPeFiBnAcluisdianlgsoal 12 FC included acsoampreocuenntdicsomprpooviudnedd oinf Appendix D interest. A complete data summary table including all 12 FC compounds is provided in Appendix D. IInn PPhhaassee 11,, tthhee PPFFOOAA aanndd PPFFOOSS rreessuullttss wweerree pprreesseenntteedd oonn tthhee ffiigguurreess aass tthheessee wweerree tthhee pprriimnaarryy FFCCss ddeetteecctteedd iinn vvaarriioouuss mmeeddiiaa ssaamplpelde.d IInn PPhhaassee 22,, iitt wwaass ffoouunndd tthhaat PPFFOOAA aanndd present PEOA and PPFFOOSS ccoonnttiinnuuee ttoo bbee tthhee pprriimmaarryy FFCCss ooff PFOS data. Again, since PFBA i iinntteerreesstt a recent aanndd tthhuuss.: compound of interes it i. tthhee ffiigguurreess iinn tthhiiss rreeppoorrtt palrseoseinntclPuFdeOd.A Tanhd PprFeOseSntdaattiao.nAogfarines,ulstinscienPtFheBAtexits ias rperciemnarticloymfpoocuusneddoofninttheeresest,saitmies aclosmopionucnluddsedex. cTephte wphreeseentfautritohnerodfisrecsuussltisoninoftohtehteextFiCs cporimmpaoruilnydsfoicuwsaerdraonntetdh.ese same compounds except where further discussion of other FC compounds is warranted. 44..11 SSUUMMMMAARRYY OOFF TTHHEE AANNAALLYYTTIICCAALL DDAATTAA QQUUAALLIITTYY AANNDD DDAATTAA RREEDDUUCCTTIIOONN PPRROOCCEESSSS AAnnsayltyiticcaall ddaattaa ffoorr tthhee PPhhaassee 22 sstuuddyy wwaass pprroovviiddeedd ffoolllloowwiinngg tthhee GGoooodd LLaabboorraattoorryy PPrraacctiicceess ((GGLLPP)) PPrroottooccooll PP22556611.. TThhee GGLLPP pprroottooccooll aanndd tthhe ssppeecciiffiieedd aannaallyyttiiccaall mmeetthhooddss ccoonnttaiinn rriiggoorroouuss qquuaalliittyy aassssuurraanncceel/qquuaalliittyy ccoonnttrrooll ((QQAAV/QQCC)) pprroovviissiioonnss iinncclluuddiinngg iinn-pphhaassee aauuddiitts,, ffullll ddooccuummenetnatattiioonn,, mmaattrriixx ssppiikkeess ffoorr eevveerryy ssaammppllee ccoolllleecctteedd aanndd aannaallyyzzeedd,, aanndd tthhoorroouugghh rreevviieewwss bbyy tthhee EExxyyggeenn QQuuaalliittyy AAssssuurraannccee UUnniitt ((QAAUU)) aanndd eexxtteermnaall ddaattaa rreevviieewweerrss,. TThhee aannaallyyttiiccaall mmeetthhooddss rreefflleecctt tthhee ssiiggnniiffiiccaanntt ddeevveellooppmmeennttaall eeffffoorrtt tthhaatt hhaass Confidential - 3M Insurance D--ocument"si Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc 4-1 Confdential- 3M Insurance Documents 3MM_ENEVN_V0000000033114499 a3MW_MNNo0r1a4s83s0o7r4 22116622..00007733 been applied t0 refine eater methods to obtain high-quality quantitative analytical daa been applied to refine earlier methods to obtain high-quality quantitative analytical data Where data quality objectives were not met, samples have been re-cxtracid and ffoorr aa ssuuiitteeoofffflluuoorroocchheemmiiccaall ccoommppoouunnddss aatt ppaarrttss ppeerr ttrriilllliioonn ((pppptt)) lliimmiittss ooff qquuaanntittitaattiioonn.. Where data quality objectives were not met, samples have been re-extracted and uaniaive data rreeaannaallyyzzeedd bbyy tthhee iinniittiiaall mmeetthhoodd oorr aann aalltteerrnnaattee mmeetthhoodd iinn aann eeffffoorrtt ttoo pprroovviiddee quantitative data. AAnnaallyyttiiccaall ddaattaa ffoorr FFCCss hhaavvee bbeeeenn rreeppoorrtteedd iinn IInnteerriimm RReeppoorrttss ffroomm tthhee EExxyyggeenn llaabboorraattoorryy.. IInn iinnssttaanncceess wwhheerree qquuaalliittyy ccoonnttrrooll ((QQCC)) ddaattaa oonn mmaattrriixx ssppiikkee rreeccoovveerriieess (accuracy of <30%), the data are not reported (NR). The NR designation does not aassssoocciiaatteedd wwiitthh aa ssaammppllee rreessuulltt wweerree oouuttssiiddee tthhee 7700 ttoo 113300%% rraannggee ooff aacccceeppttaannccee (accuracy of +30%), the data are not reported (NR). The NR designation does not ccoonnnnoottee eeiitthheerr hhiigghh oorr llooww ssaammppllee ccoonncceennttrraattiioonnss bbuutt rraatthheerr oonnllyy rreefflleeccttss tthhaatt aannaallyyttiiccaall ccoonnddiittiioonnss ddiidd nnoott mmeeeett tthhee ccrriitteerriiaa fFoorr ffiieelldd mmaattrei:x ssppiikkee rreeccoovveerriieess ((aaqquueeoouuss ssaammpplleess)) oorr laboratory mati spikes (solid samples) that would allow the reporting of quaniiative ldaabtorawitotrhyanmaatsrsiexsssepdikaecscu(sroalciyd osfam=3p0l%es.) Tthhaet ewxoteunltd taollhoiwcthhedarteapomratiyngbeofabqsuenatntidtuaetivteo data with an assessed accuracy of30%. The extent to which data may be absent due to NNRR ddeessiiggnnaattiioonnss aatt llooccaattiioonnss tthhaatt aarree iimmppoorrttaanntt ffoorr tthhee eevvaalluuaattiioonnoforf eremmedeidaiall aalltteerrnnaattiivveess is being evalusted to develop the appropriate cause of action fo losing any criial data is being evaluated to develop the appropriate cause of action for closing any critical data aps. Other dat reported with non-numerica values include results ha ae assigned ND. gaps. Other data reported with non-numerical values include results that are assigned ND bbeeccaauussee tthhee aannaallyyttee wwaass nnoott ddeetteecctteedd aatt oorr aabboovvee tthhee LLiimmiitt ooff QQuuaantnitittaattiioonn (LLOOQQ).). WWhheenn wwaatteerr ssaammpplleess wweerree pprreeppaarreedd ffoorr eexxttrraaccttiioonn aanndd aannaallyyssiiss,, tthhee ssaammpplleess wweerree ddiilluutteedd 1: ino an organic solvent prior to analysis resulting in dilution by factorof 2. Because c1a:1liibnrtaotiaonn osrtgaanndircdssolwveernet ppriroerpatoreadnailnysaisprreseumlitixnegdinwadtileurtsioonlvbeynta fmaicxttourreo,f 2c.alBibercaatuisoen cstaalinbdraartdiosndisdtannodtarrdescewiveerethperespaamreedtrienatamenptr.e-mAsixeadrewsualtte,r:tshoelvaennatlymtiicxatlurmee, tchaoldibrtaatrigoent LOG of standards 0d.i0d25 nnogt/mrLe.cewiavse nthote astatmaienetdreaantmd etnhet.nAomsinaalresLuOlt,Qtohfe0.a0n5al0ytnicgailmLm. ewtahsodaptpalrigeedt LOQ of 0.025 ng/mL was not attained and the nominal LOQ of 0.050 ng/mL was applied pes were detected in the method blanks, the blanks were evaluated and the LOQ was ttoo rreessuullttss tfi-roomm aannaallyyttiiccaall rruunnss tthhaatt mmeett tthhee mmeetthhoodd bbllaannkk QQCC ccrriitteerriiaa.. IInn iinnssttaanncceess wwhheerree peaks were detected in the method blanks, the blanks were evaluated and the LOQ was While 100s were elevated fo certain samples and matics, data integrity and usability ddeetteerrmmiinneedd bbyy tthhee lloowweesstt ssttaannddaarrdd aanndd mmeetthhoodd bbllaannkk ppeerrffoorrmmaannccee tthhaatt mmeett QQCC ccrriitteerriiaa.. While LOQs were elevated for certain samples and matrices, data integrity and usability ffoorr tthhee iinntteennddeedd ppuurrppoossee wweerree nnoott aaffffeecctteedd.. laboratory duplicate (slid samples) sample analysis was performed. The primary and IInn aaddddiittiioonn ttoo eeaacchh pprriimmaarryy ssaammppllee aannaallyyssiiss,, aa ffiieelldd dduupplliiccaattee ((aaqquueeoouuss ssaammpplleess)) oorr laboratory duplicate (solid samples) sample analysis was performed. The primary and nme Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-2 33MM_EENNVV_0000000033115500 W3M_MNMONT041848330077S5 22116622..00007744 dduupplliiccaattee rreessuullttss wweerree rreedduucceedd ttoo. a ssiinnggllee vvaalluuee iinn oorrddeerr oto ssiimmpplliiffyy rreeppoorrtiinngg. TThhee ddaattaa rreedduuccttiioonn pprroocceessss ccoonnssiisstteeddooffcaclaclcuullaattiinngg tthhee aavveerraaggee ccoonncceennttrraattiioonn ((aarriitthhmmeettiicc mmeeaann)) ffoorr sseettss ccoommpprriisseedd ooff nnuummeerriicc vvaalluueess.. IInn iinnssttaanncceess wwiitthh mmiixxeedd nnuummeerriicc vvaalluueess aanndd nnoonn-- nnuummeerriicc vvaalluueess ((NNDD),), tthhee nnuummeerriicc vvaalluueess wweerree ccaarrrriieedd tthhrroouugghh ttoo rreepprreesseenntt tthhee mmeeddiiaa ccoonncceenntrtraattiioonnss.. ITtt sshhoouulldd bbee nnootteedd tthhaatttthhe ddaattaa rreedduuccttiioonn ccoonnvveennttiioonn ddeessccrriibbeedd sabhoovvee iiss ccoonnsseerrvvaattiivvee aanndd mmaayy rreessuultliintn oovveerreessttiimmaattiioonnooffsaccttuuall ccoonncceennttrraattiioonnss. 44..22 HHYYDDRROOLLOOGGIICCAALL IINNTTEERRPPRREETTAATTIIOONN The purpose of the hydrologic evaluation performed by WESTON at the Cottage Grove TSihtee piunrpMoasye o2f0t0h6e hwyadsrotloogeicvaelvuaatlueattihoen apreerafoormf egdrobuyndWwaEtSeTrOcNaptautrteheinCdoutctaegdebGyrotvhee pSuitmepiinngMofaytw2o00p6rodwuacstioton weevlalsua(tPeW-th0e3 aarneda PoWf-0g6r)o,unadnwdactaelrcuclaaptetuarequiinfedrucpeardambeytertsh.e pumping of two production wells (PW-05 and PW-06), and calculate aquifer parameters. TThhee aarreeaa ooff ggrroouunnddwwaatteerr ccaappttuurree wwaass eessttiimmaatteedd bbyy ccoonnssttrruuccttiinngg aa ggrroouunnddwwaatteerr eelleevvaattiioonn contour map using data collected during a period when both production wells were contour map using data collected during a period when both production wells were opening operating. SSiixx ootthheerr pprroodduuccttiioonn wweellllss ooppeerraatte iinntteerrmmiitttteennttllyy bbaasseedd oonn cilty l?acility wwaatteerr ddeemmaanndd.. TThheessee wweellllss aarree iinn tthhee nnoorrtthh aanndd nnoorrtthhwweesstt ppaarrtt ooff tthhee ssiittee ((sseeee FFiigguurree 22--44)).. AAlltthhoouugghh tthhee ddrraawwddoowwnn eeffffeeccttss ooff tthheessee wweellllss hhaass nnoott bbeeeenn eevvaalluuaatteedd aass ppaarrtt ooff tthhiiss aasssseessssmmeenntt,, aroundwater being captured by these wells is upgradient of the manufacturing area and groundwater being captured by these wells is upgradient of the manufacturing area and known disposal srs. known disposal areas. TThhee ccaappttuurree zzoonnee ffoorr PPWW--0055 aanndd PPWW--0066 wwaass iinntteerrpprreetteedd bbyy ccoonnssttrruuccttiinngg ggrroouunnddwwaatteerr flow lines perpendicular to the grounder elevation contours. The estimated width of fclaopwturlienedsurpienrgpepnedriicoudlsarthtaot thpreodgurcotuinodnwealtelrselPeWva-t0io5n acnodntoPuWr-s.05Thaereesbtoimthatoepderwaitditnhg oisf cinadpitcuarteeddubryintghepfelroiowdisntehsatdeppriocdtuedctiionnFixgvuerlles 4P-1W. -T0h5e aanctduaPlWca-p0t6uraerezobnoethofotpheersaetinweglliss iwnildlicbaetedslbigyhtthlye lfelosswsliinncees pdreopdiucctetdioinn wFeilglurPeW4--01.5Tphuemapcstuailntcearpmituttreentzloyneanodf tphreosdeucwteilolns wweillll bPeW-s0lig6hitlsyshleustsdsoinwcne pperroiodduicctailolny wfoerllmaPiWnt-0e5nanpcuemapcstiivnitteiersmoitrtewnhtleynatnhde ipnrocidnuecrttioonr wisenllotPoWpe-r0a6tinisg.shAust idnodwicnatpeedriiondFiciaglulryef4o-r1,mtahientaerncasnocfecaacpttiuvriteieesxtoernwdshecnastthteo iMnWci-n1er2aitonr is not operating. As indicated in Figure 4-1, the area of capture extends east to MW-12 in the FTA tthhee DDS5 AArreeaa,, aanndd wweesstt t1o0 aa ppooiinntt mmiiddwwaayy bbeettwweeeenn PPWW-S-55 aanndd tthhee WWeesstt CCoovvee,, iinncclluuddiinngg the FTA. Confidential - 3M Insurance D--ocument"si Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc 4-3 Confdential- 3M Insurance Documents 22116622..00007755 3MM_ENEVN_V0000000033115511 W_MNOT48307S 3M MN01483076 AAss sshhoowwnn iinn FFiigguurree 44--11,, dduurriinngg ppuummppiinngg,, tthhee ggrroouunnddwwaatteerr eelleevvaattiioonn iinn tthhee vviicciinniittyyoofft'thhee ttwwoo pprroodduuccttiioonn wweelllls isis sseevveerraall ffeeeett bbeellooww tthhee nnoommiinnaall eelleevvaattiioonn ooff tthhee ssuurrffaaccee wwaatteerr iinn tthhee M Misisssiissssiippppii RRiivveerr.. TThhiiss ssuuggggeessttss tthhaatt tthhee ppuummppiinngg ooff tthheessee ttwwoo wweellllss iinndduucceess g`grorouunnddwwaatteerr bbeenneeaatthh tthhee rriivveerr ttoo ffllooww ttoowwaarrdd tthheessee wweellllss iinn tthhee iimmmmeeddiiaattee aarreeaa.. DDeessppiittee tthhee pprrooxxiimmiittyy ooff tthhee MMiissssiissssiippppii RRiivveerr ttoo tthhee pprroodduuccttiioonn wweelllls,, tthhee rriivveerrbbeedd sseeddiimmeennttss aappppeeaarr ttoo lliimmiitt tthhee aammoouunntt ooff hhyyddrraauulliicc ccoommmmunuinciacattiioonn bbeettwweeeenn ssuurrffaaccee wwaatteerr aanndd g`grorouunnddwwaatteerr iinn tthhiiss aarreeaa.. AAddddiittiioonnaall ddaattaa ssuuppppoorrttiinngg tthhiiss ccoonncclluussiioonn wwaass oobbsseerrvveedd iinn tthhee ggrroouunnddwwaatteerr eelleevvaattiioonn ddaattaa ccoolllleecctteedd ffrroomm aaddjjaacceenntt mmoonniittoorr wweellllss dduurriinngg ppeerriiooddss tthhaatt pprroodduuccttiioonn wweellll PPW W--55 wwaass ooppeerraattiinngg.. TThhee wwaatteerr lleevveell ddaattaa ccoolllleecctteedd ffrioomm tthhee aaddjjaacceenntt oobbsseerrvvaattiioonn wweellllss sshhoowweedd tthhaatt aalltthhoouugghh aa rreecchhaarrggee bboouunnddaarryy ((tthhee rriivveerr)) wwaass eennccoouunntteerreedd dduurriinngg ppuummppiinngg,, tthhee wwaatteerr lleevveellss iinn tthhee oobbsseerrvvaattiioonn wweellllss ddiidd nnoott rreeaacchh eeqquuiilliibbrriiuumm aanndd wweerree ccoonnttiinnuuiinngg ttoo ddeecclliinnee aatt tthhee eenndd ooff tthhee ppuummppiinngg ppeerriioodd.. TThhiiss iinnddiiccaatteess tthhaatt tthhee lleeaakkaaggee rraattee ffrroomm tthhee rriivveerr ttoo tthhee aaqquuiiffeerr wwaass lleessss tthhaann tthhee ddiisscchhaarrggee rraatteeooff tthhee ppuummppiinngg wweellll. AA ssuummmmaarryy ooff tthhee ccoommppuutteedd aaqquuiiffeerr ppaarraammeetteerrss uussiinngg tthhee aapppprroopprriiaattee aannaallyyttiiccaall mmeetthhooddss ffoorr ssiittee ccoonnddiittiioonnss iiss sshhoowwnn iinn TTaabbllee 44--11.. AAss sshhoowwnn iinn TTaabbllee 44--11,, tthhee ggeeoommetertriicc mmeeaann ooff tthhee ttrraannssmmiissssiivviittyy vvaalluueess ccaallccuullaatteedd uussiinngg tthhee TThheeiiss ddrraawwddoowwnn,, CCooooppeerr--JJaaccoabb ddrraawwddoowwnn,, aanndd TThheeiiss rreeccoovveerryy mmeetthhooddss aarree 1155,,227755 ssqquuaarree ffeocett ppeerr ddaayy ((fdtZa/dya)y,), 1177,,227799 dftZe/dya,y, aanndd 2211,,222288 fdtZa/dya.y. TThheessee vvaalluueess aarree iinnddiiccaattiivvee ooff tthhee hhiigghh ppeerrmmeeaabbililiittyy ooff tthhee aalllluuvviiaall sseeddiimmeennttss tthhaatt pprroodduuccitiioonn wweellllss PPWW--55 aanndd PPWW--66 aarree ssccrreeeenneedd wwiitthhiinn.. TThhee ggeeoommeettrriicc mmeeaann ooff tthhee ssttoorraatiivviittyy vvaalluueess ccaallccuullaatteedd uussiinngg tthhee TThheeiiss ddrraawwddoowwnn aanndd CCooooppeerr--JJaaccoobb mmeetthhooddss iiss 0.00.0010133 aanndd 00..00001111,, rreessppeeccttiivveellyy.. BBaasseedd oonn tthhiiss aannaallyyssiiss,, tthhee ppuummppiinngg aatt PPWW--55 aanndd PPWW--66 iiss lliikkeellyy ccaappttuurriinngg ggrroouunnddwwaatteerr bbeenneeaatthh tthhee mmaajjoorriittyyoofftthhee cceennttrraall ppllaanntt aarreeaa iinncclluuddiinngg mmoosstt ooff tthhee DDS5 AArreeaa.. HHoowweevveerr,, tthheessee ppuummppiinngg wweellllss aarree nnoott ccaappttuurriinngg ggrroouunnddwwaatteerr ecaasstt ooff MMWW--1122 wwhhiicchh iiss llooccaatteedd aatt tthhee eeaasstteerrnn eeddggeeoofftthhee DDS5 AArreesa.. TThhiiss ccaappttuurree eelfTfeeccttiivveenneessss iiss ssuuppppoorrtteedd bbyy aanndd ccoonnssiisstteenntt wwiitthh tthhee llooww ddeetteeccttiioonnss ooff FFCCss iinn tthhee ppoorreewwaatteerr ssaammpplleess ffrroomm llooccaattiioonnss wweesstt ooff MMWW--1122 ((sseeee SSuubbsseeccttiioonn 44..55..11 aanndd FFigiuregs44-u-1133rttooe44--11s55)).. anon mr Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-4 22116622..00007766 33MM_EENNVV_0000000033115522 I3MM_MMNNO011448833007777 us overs anens 4.3 ON-SITE AREAS 44..33.11 DD11//DD22 AArreea--a- FFoorrmmeerr HHFF TTaarr NNeeuutrtraalliizzaattiioonn BBaassiinn//FFoorrmmeerr SSlluuddggee Suez Disposal Area sir commer 4.3.1.1 Groundwater Two Phase 2 groundwater monitoring wells (MW-103 and MW-104) were installed and ssaammpplleedd ttoo aasssseessss tthhee pprreesseennccee ooff FFCCss iinn ggrroouunnddwwaatteerr iimmmmedeidaiatteellyy ddoowwnnggrraaddiieennttooff tthhee D2 area and to supplement existing Phase 1 groundwater sampling results from monitoring wells MW-101 and MW-102 which are associated with the D1 Area. The Phase 2 well locations in the D2 Area are presented in Figure 3-1. Both Phase 2 wells a were installed to a depth of 88 ft bgs in unconsolidated sand and gravel. The average depth to water in the D1/D2 Area is approximately 77 ft bgs. The wells were sampled on September 8, 2006. The Phase 2 groundwater sampling results at the D1/D2 Areas (as presented in Figure 4-2 aanndd TTaabbllee 44--22)) sshhooww PPFFOOAA wwaass ddeetteecctteedd aatt ccoonncceennttrraattiioonnss ootf~ 441144 ppppbb ((MMWW-1-10033)) aanndd 619 ppb (MW-104). The higher concentration of 619 ppb was present in MW-104 which is centrally located directly downgradient from the D2 Area. PFOS analyses of groundwater samples from Phase 2 wells MW-103 and MW-104 indicates the result as Nil. hsPFBA analyses indicate detected concentrations of 318 ppb (MW-103) and NR (MW- 102). 44..33..11..22 SSooiill During installation of the two groundwater monitoring wells (MW-103 and MW-104) soil samples were collected and analyzed for the four FC parameters (PFBS, PFHS, PPFFOOSS aanndd PPFFOOAA)) ttoo aasssseessss tthhee pprreesseennccee ooff FFCCss iinn ssooiill iimmmmedediaiatteellyy ddoowwnnggrraaddiieenntt oofftthhee D2 area and to supplement existing Phase 1 soil sample results collected from soil borings in and around the D1/D2 Area. (PFBA was not analyzed because these samples Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt"ssis4-5 33MM_EENNVV_0000000033115533 3M MN01483078 22116622..00007777 were collected prior to the implementation ofthe expanded lstofanalytes) The Phase 2 wsoielrescaomlplelceteTdocpartioiorntso athree ipmrepsleenmteedntaitnioFnigoufrtehe3-e1.xpaSnodiledslaimstploefsanwaelryetesc.)olTehcetePdhafsreom2 Psohialsesa2mmpolenitloocraitniognwselareboprriensgesntteoda idnepFtihgoufre23-1f.etSodiulrisnagmpthleesweweekrse ocfolJluecnteed12fraonmd PJuhnaese129,m20o0n6,itoring well borings to a depth of 25 feet during the weeks of June 12 and June 19, 2006. The Phase 2 soil sample rests from MW-103 and MW-104, summarized in Table 4-3 Tanhde oPnhaFsiegu2reso4-il3,saimndpicleatreesthualttsPfFroOmA MwW s -d1e0t3ectaenddaMt cWon-c1e0n4tr, astuimonms arrainzgeidnginrToambl0e.342-13 and on Figure 4-3, indicate that PFOA was detected at concentrations ranging from 0.321 ppppbb ((00--66 iinncchheess,, M MWW-1-10044)) ttoo 1166..88 ppppbb(5(5--1100 ffeeeett ddeeeepp,, M MWW-1-0140)4.). AAtt tthhee ddeeeeppeesstt iinntteerrvvaall sampled (20-25 fect) the concentrationof PFOA is 3.14 ppb at MW-103. sampled (20-25 feet)the concentration of PFOA is 3.14 ppb at MW-103. PROS was detested in soil samples collected from MW-103 and MW-104 at PcoFnOcSentwrtaisonsdertaencgteidng ifnromsoi0l.24sa7mppplbes(1c5o:l2l0ecfteedt, fMrWom-10M3)W-t1o0636.9anpdpb M(0W-6-1i0n4chesa,t cMoWn-c1e0n3t)ra,tioAnts trahnegdinegspefrsotmin0t.e2r4va7l pspabmp(l1e5d-20(2f0e-e2t5, MfeWct)-1a0t3)MtWo-1606.39,ppPbFO(0S-6wainschneost, MdetWec-t1ed0.3)P. FAOtSthaesodweaepsensottindetetrevsatledsbaemlpolweda d(2ep0t-2h5offe1e0t)fecatt aMt MWW--11030,4PFOS was not detected. PFOS also was not detected below a depth of 10 feet at MW-104. PPFHHSSaannaallyysseess iinnddiiccaattee ddeetteecctteedd ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..115544 ppppbb ((MMWW-1-10044,, 1155:-2200 eet) 0/0 7831 ppb (VW-104, 6 inches to feet interval) PFHS was only detected at the feet) to 07831 ppb (MW-104, 6 inches to 5 feet interval). PFHS was only detected at the MW-104 00--66 iinncchh ddeepptthh aatt MMWW--110033 ((00..338888 ppppbb)) aanndd wwaass nnoott ddeetteecctteedd bbeellooww aa ddeepptthh ooff 2200 ffeeeett aatt MW-104. PPFEBBSS wwaass eeiitthheerr NNDD oorr NNRR ffoorr eeaacchh oofftthhee ssooiill ssaammpplleess ccoolllleecctteedd ffrroomm MMWW--110033 aanndd MMWW--110044. 443.3:.22 DDS5 AArreeaa-- FFoorrmmeerr SSoolliiddss BBuurrnn PPiitt 44..33..22. 11 GGrroouunnddwwaatteerr TTwwoo ggrroouunnddwwaatteerr mmoonniittoorriinngg wweellllss ((MMWW--110099 aanndd MMWW-1-11100)) wweerree iinnssttaalllleedd aanndd ssaammpplleedd to assess the presence of FCs in groundwater downgradient of the DS Area and to to assess the presence of FCs in groundwater downgradient of the D5 Area and to Supplement ising Phase 1 groundvate sampling results rom monitoring ell MW-12. supplement existing Phase 1 groundwater sampling results from monitoring well MW-12. The Phase 2 well locations are presented in Figure 3-1. The Phase 2 wells, MW109 and The Phase 2 well locations are presented in Figure 3-1. The Phase 2 wells, MW109 and MMWW-1-11100,, wweerree iinnssttaalllleedd aass aa sshhaallllooww aanndd ddeeeepp wweellll cclluusstteerr.. DDuurriinngg tthhee ddrriilllliinngg ooff tthhee ddeeeeppeerr wweellll ((MMWW--111100)) aa ppeerrcchheedd wwaatteerr ttaabbllee wwaass eennccoouunntteerreedd aatt 3366 ttoo 4466 ffeeeett bbggss aass aa Confidential - 3M Insurance D--ocument"sio Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc 4-6 Confdential- 3M Insurance Documents 22116622..00007788 33MM_EENNVV_0000000033115544 W3M_MMNNO0T144883300779 rreessuulltt ooffaa ssilltyy ccllaayy llaayyeerr wwhhiicchh wwaass eennccoouunntteerreedd ffrroomm 4466 ttoo 7711 ffeeeett bbegss.. MMWW--110099 wwaass iinnssttaalllleedd ttoo aa ddeepptthhooff4466 ffeecett bbgess aanndd MMWW--111100 wwaass iinnssttaalllleedd ttoo aa ddeepptthh ooff 110066 ffeecett bbegss.. BBootthh wweellllss aarree ccoommpplleetteedd iinn uunnccoonnssoolliiddaatteedd ssaanndd aanndd ggrraavvele.l. TThhee wweellllss wweerree ssaammpplleedd oonn SSeepptteemmbbeer7r7,, 22000066. TThhee PPhhaassee 22 ggrroouunnddwwaatteerr ssaammpplliinngg rreessuullttss ffrroomm MMWW--110099 aanndd M MWW11ll00 aarree sshhoowwnn iinn FFiigguurree 44--22 aanndd TTaabbllee 44--22. PPFFOOAA wwaass ddeetteecctteedd iinn bbootthh wweellllss aatt ccoonncceennttrraattiioonnss ooff 113366 ppppbb ((MMWW--111100)) aanndd 119999 ppppbb ((MMWW-1-0190)9.). PPFFOOSS aannaallyysseess wweerree NNRR ffoorr MMWW-1-10099 aanndd 2266 ppppbb tfborr MMWW--111100. PPFEBBAA wwaass ddeetteecctteeddaatt aa ccoonncceennttrraattiioonn ooff 2233.3.3 ppppbb aatt MMWW--110099 aanndd NNRR aatt MMWW-1-11100.. 44.33.22.22 SSooiill TThhee PPhhaassee 22 ssooiill ssaammppllee rreessuullttss aarree ccoommpprriisseedd ooff ssooiill ssaammpplleess ccoolllleecctteedd dduurriinngg iinnssttaallllaattiioonn ooff mmoonniittoorriinngg wweellllss MMWW-1-10099,, ddoowwnnggrraaddiieennttooftf thhee DDS5 AArreeaa aanndd ssooiill bboorriinnggss ddrriilllleedd aatt 66 llooccaattiioonnss ((SSBB--DD5SBBO0T1 tthhrroouugghh SSBB--DDSSBB0066)) wwiitthhiinn tthhee Ffoooottpprriinntt ooff tthhee DDS5 AArreeaa.. SSaoiill ssaammpplleess wweerree ccoolllleecctteedd aanndd aannaallyyzzeedd ffoorr tthhee ffoouurr FFCC ppaarraammeetteerrss ((PPFFBBSS,, PPFEHHSS,, PPFROOSS aanndd PPFFOOAA)) ttoo aasssseessss tthhee pprreesseennccee ooff FFCCss iinn ssooiill iinn tthhee vviicciinniittyy ooff tthhee DDS5 AArreeaa aanndd ttoo ssuupppplleemmeenntt PPhhaassee 11 ssooiill ssaammppllee rreessuullttss ccoolllleecctteedd ffrroomm ssooiill bboorriinnggss iinn aanndd aarroouunndd tthhee DDS5 AArreeaa..TThhee PPhhasea22ssosioelil ssaammppllee llooccaattiioonnss aarree pprreesseenntteedd iinn FFiigguurree 33--11.. TThhee ssooiill rreessuullttss ffrroomm MMWW--110099 iinnssttaallllaattiioonn aarree pprreesseenntteedd oonn FFiigguurree 44--33 aanndd tthhee ssooiill rreessuullttss ffrroomm tthhee bboorriinnggss aarree pprreesseenntteedd oonn FFiigguurree 44--44.. SSaoiill ssaammpplleess wweerree ccoolllleecctteedd ffrroomm tthhee MMWW-110099 wweellll bbaorriinngg aanndd ffrroomm tthhee ssiixx ssooiill bboorriinnggss ttoo aa ddeepptthhooff 2255 ffeeeett wwiitthh tthhee eexxcceeppttiioonn ooff oonnee llooccaattiioonn ((SSBB--DDS5BBO0S5)) wwhheerree tthhee bboorriinngg wwaass tteerrmmiinnaatteedd aatt 1100 ffeeeett dduuee ttoo GGeeoopprroobbee rreeffuussaal.l. TThhee PPhhaassee 22 ssooiill ssaammpplleereressuullttss aarree ssuummmmarairizzeedd iinn TTaabbllee 44--33.. PPFFOOAA wwaass ddeetteecctteedd iinn tthhee ssoiill ssaammpplleess ccoolllleecctteedd ffrroomm MMWW--110099 bboorriinngg ddoowwnnggraraddiieenntt ooff tthhee DDS5 AArreeaa aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 11..4422 ppppbb ((55--1100 ffeeeett ddeeeepp)) ttoo 3300..77 ppppbb ((2200--2255 ffeeeett)). TThhee ssaammpplleess ccoolllleecctteedd ffrroomm tthhee PPhhaassee 22 ssooiill bboorriinnggss iinn tthhee DDS5 AArreeaa iinnddiiccaatteedd ccoonncceennttrraattiioonnss ooff PPFFOOAA rraannggiinngg ffrroomm 00..558877 ppppbb ((SSBBCC--DDS5BBO0S5,, 00--66 iinncchheess)) ttoo 220000 ppppbb ((SSBBCC--DDS5BBO022,, 2200--2255 ffeeee)t).. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuuorrmaannccee DDooccuummeenntt"ssi4-7 22116622..00007799 33MM_EENNVV_0000000033115555 I3MM_MMNNO011446833008800 PPFROOSS wwaass ddeetteecctteedd iinn tthhe ssooiill ssaammpplleess ccoolllleecctteedd ffir-oomm MMWW--110099 bboorriinngg ddoowwnnggraraddiieenntt ooff tthhee DDS5 AArrceaa aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 99..3399 ppppbb ((55--1100 ffeeeett ddeeeepp)) ttoo 8822..22 ppppbb ((00..55--55 ffeeeett)).. TThhee ssaammpplleess ccoolllleecctteedd ffrroommtthheessiolil bboorriinnggss iinn tthhee DDS5 AArreeaa iinnddiiccaatteedd ccoonncceennttrraattiioonnss 10 eet) ooff PPFFOOSS rraannggiinngg ffrroomm 33..1155 ppppbb ((SSBBCC--DDS5BBO022,, 2200--2255 ffeeeett)) ttoo 22.,665500 ppppbb ((SSBBCC--DDS5BBO022,, 55-- 10 feet). PPFEHHSS wwaass ddeetteecctteedd iinn tthhee MMWW--110099 bboorriinngg ddoowwnnggrraaddiieenntt ooff tthhee DDS5 AArreeaa aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..220022 ppppbb ((55--1100 ffeeeett ddeeeepp)) ttoo 11..8811 ppppbb ((2200--2255 ffeeeett)).. TThhee ssaammpplleess ccoollllecctteedd ffrroomm tthhee PPhhaassee 22 ssoiill bboorriinnggss iinn DDS5 AArrceaa iinnddiiccaatteedd ccoonncceennttrraattiioonnss ooff PPFFHSS rraannggiinngg ffrroomm 2200..11 ppppbb ((SSBBCC--DD5SBB0O6,, 1155:-2200 ffeeet)) ttoo 00..221155 ppppbb ((SSBBCC--DDS5BBOL0,1, 00--66 iinncchheess)).. PPFEBBSS rreessuultss ooffssaammpplleesscocolllleecctteedd ffrroomm tthhee MMWW--110099 bboorriinngg iinnddiiccaatteedd NNRR ffoorr eeaacchh ooftf thhee ssooill ssaammpplleess aannaallyyzzeedd.. TThhee ssaammpplleess ccoolllleecctteedd ffrroomm tthhee PPhhaassee 22 ssaoiill bboorriinnggss iinn tthhee DDS5 AArreeaa iinnddiiccaatteedd ccoonncceennttrraattiioonnss ooff PPFFBBSS rraannggiinngg ffrroomm 00..224444 ppppbb ((SSBBCC--DDSSBBO0Z2,, 1155--2200 ffeeeett)) t1o011..6677 ppppbb ((SSBBCC--DDS5BBO0G6,, 55--1100 feecet)t).. 44..33..33 DDO9 AArreeaa--- FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiitt 44..33..33..11 GGrroouunnddwwaatteerr SSaammplpilinngg RReessuullttss TThhrreeee ggrroouunnddwwaatteerr mmoonniittoorriinngg wweellllss ((MMWW-1-10055,, MMWW--110066 aanndd MMWW-1-10077)) wweerree iinnssttaalllleedd aanndd ssaammpplleedd ttoo aasssseessss tthhee pprreesseennccee ooff FFCCss iinn ggrroouunnddwwaatteerr iinn tthhee DD99 AArreeaa aanndd ttoo ssuupppplleemmeenntt eexxiissttiinngg PPhhaassee 1| ggrroouunnddwwaatteerr ssaammpplliinngg rreessuullttss ffrroomm mmoonniittoorriinngg wweellll MMWW--1133 w`whhiicchh iiss aaddaiacceenntt ttootthhee DD99 AArreeaa.. TThhee PPhhaassee 22 wwaellll llooccaattiioonnss aarree pprreesseenntteedd iinn FFiigguurree 33--11. The Phase 2 wells; MW-105 (owngradient), MW-106 (in the DO Area) and MW-107 T(uhpegrPahdaiscen)2, wweelrles; MinsWta-l1le0d5 t(ododwenpgthrasdioefnt)9,6.M5,W9-5106an(din9th1eS Df9t Abyrsea)reasnpedctMivWel-y10i7n (upgradient), were installed to depths of 96.5, 95 and 91.5 ft bgs respectively in approximately 85fbes. Thewelsweresampleodn September 3, 2006 uunnccoonnssoolliiddaatteedd ssaanndd aanndd ggrraavvele.l. TThhee aavveerraaggee ddeepptthh ttoo wwaatteerr iinn tthhee DD99 AArreeaa iiss approximately 85 ft bgs. The wells were sampled on September 8, 2006. The Phase 2 groundwater sampling resultsa the DO Arca (MW-105, MW-106 and MWT10h7e)Pahraespere2sgenroteudndinwaTtaebrlesa4m-2plainndg orensuFlitgsuartet4h-e2D9 Area (MW-105, MW-106 and MW- 107) are presented in Table 4-2 and on Figure 4-2. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc ---- is4-8 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 22116622..00008800 33MM_EENNVV_0000000033115566 M3M_MNMON1041E4833008811 PFOA analyses indicate Nil for the samples from MW-105 and MW-106. The ccoonncecnterantitonrooafftPPiFFoOOAnA ddeetteecctteedd iinn MMWW--110077 iiss 2244..55 ppppbb.. PPFFOOSS aannaallyysseess iinnddiiccaattee NNRR ffoorr tthhee ssaammpplleess ffrroomm eeaacchh ooff tthhee tthhrreeee wweellllss.. PPFFBBAA wwaass ddeetteecctteedd iinn PPhhaassee 22 ssaammpplleess aatt ccoonncceennttrraattiioonnss ooff 7766..33 ppppbb~, 6644..33 ppppbb aanndd 2299..77 ws2 sorsumping moss ppb at MW- 105, MW- 106 and MW- 107, respectively. 4.3.3.2 Soil Sampling Results TThhee PPhhaassee 22 ssooiill ssaammppllee rreessuullttss iinn tthhee DD99 AArreeaa aarree ccoommpprriisseedd ooff ssooiill ssaammpplleess ccoolllleecctteedd during the installation of three monitoring wells MW-105, MW-106 and MW-107 and ~'our soil borings SB-D9B01, SB-D9B02, SB-D9B03 and SB-D9B04. Soil samples were collected and analyzed for the four FC parameters (PFBS, PFHS, PFOS and PFOA) to aasssseessss tthhee pprreesseennccee ooff FFCCss iinn ssooiill iinn tthhee DD99 AArreeaa. TThhee PPhhaassee 22 ssaammppllee llooccaattiioonnss aarree presented in Figure 3-1. Soil samples were collected from the monitoring well borings and from the soil borings to a depth of 25 feet. The Phase 2 soil sample results are summarized in Table 4-3 and depicted in Figures 4-3 and 4-5. PFOA was detected in the D9 Area soil samples at concentrations ranging from 0.0620 ppppbb ((SSBBCC--DD99BB0033,, 2200--2255 ffeeeett)) ttoo 2211.,880000 ppppbb ((SSBBCC--MMWW110066,, 2200--2255 ffeeeett)).. TThhee concentrations detected at MW-106, MV~r-107, D9B01 and D9B04 range from 13.5 ppb (SBC-MWl06, 0-6 inches) to 21,800 ppb (SBC-MWl06, 20-25 feet). The sample results from the southeast portion of the D9 Area (SBC-MW-105, SBC-D9B02 and SBCDD99BBO033)) iinnddiiccaatteedd lloowweerr ccoonncceennttrraattiioonnss ooff PPFFOOAA rraannggiinngg ffrroomm 00..00662200 ppppbb ((SSBBCC--DD99BBO0033,, 2200--2255 ffeeeett)) ttoo 220055 ppppbb ((SSBBCC--MMWW l10055,, 55--1100 ffeeeett)).. PPFFOOSS wwaass ddeetteecctteedd iinn tthhee DD99 AArreeaa aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 11..0011 ppppbb ((SSBBCC-- D9B03, 10-15 feet) to 104,000 ppb (SBC-MWl07, 15-20 feet). The concentrations detected at MW-106, MW-107, D9B01 and D9B04 range from 47.6 ppb (SBC-MWl06, 0-6 inches)to 104,000 ppb (SBC-MW107, 15-20 feet). The sample results collected from the southeast portion of the D9 Area (MW-105, D9B02 and D9B03) indicated lower Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttx ss4-9 22116622..00008811 33MM_EENNVV_0000000033115577 3M MN01483082 concentrations of PFOS ranging from 0.672 ppb (SBC-MWl05, 20-25 feet) to 318 ppb ((SSBBCC--MMWW10l055,, 55--1100 ffeeeett)).. PPFFHHSS wwaass ddeetteecctteedd iinn tthhee DD99 AArreeaa aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..448855 ppppbb ((SSBBCC-- D9B03 duplicate, 15-20 feet) to 3,470 ppb (SBC-MWl06, 20-25 feet). The concentrations detected at MW-106, MV~r-107, D9B01 and D9B04 range from 1.78 ppb (SBC-MWl07, 0-6 inches) to 3,470 ppb (SBC-MWl06, 20-25 feet). The sample results ffrroomm tthhee ssoouutthheeaasstt ppoorrttiioonnooff tthhee DD99 AArreeaa ((MMWW-1-10055,, DD9gBB0022 aanndd DD9gBB0033)) iinnddiiccaatteedd lloowweerr concentrations of PFHS ranging from 0.485 ppb (SBC-D9B03 duplicate, 20-25 feet) to 66..0055 ppppbb ((SSBBCC--BBO9BBO30,3, 55--1100 ffeeeett)).. PFBS was detected in the D9 Area at concentrations ranging from 0.218 ppb (SBCD9B03, 20-25 feet) to 139 ppb (SBC-MWl06, 20-25 feet). 44..33..44 W Waasstteewwaatteerr TTrreeaattmmeenntt PPllaanntt AArreeaa A Phase 2 monitoring well (MW-108) was installed immediately downgradient of the facility's wastewater treatment plant (WWTP) area to provide soil and groundwater data in this area, which had not previously been assessed. Well MW-108 was installed to a depth of 103.5 ft bgs in unconsolidated deposits. The location of MW-108 is shown on Figure 3-1. The depth to water in MW-108 is approximately 95 ft bgs. The well was sampled on September 8, 2006. 44.. 33.44.. 11 GGrroouunnddwwaatteerr SSaammppliling RReessuulltts TThhee PPhhaassee 22 ggrroouunnddwwaatteerr ssaammpplliinngg resuullts doowwnnggraraddiieenntt of tthhe W WWWTTPP area ((MMWW-1-10088)) are shown in Table 4-2 and on Figure 4-2. PFOA and PFOS analyses indicate NR for the sample from MW-108. PFBA was detected at a concentration of 219 ppb. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc or "i10 4-10 Confidential - 3M IInnssuurraannccee DDooccuummeennttss Confdential ~ 3M 22116622..00008822 33MM_EENNVV_0000000033115588 3M MN01483083 44.33..44.22 SSooiill SSaammpplliinngg RReessuullttss TThhee PPhhaassee 22 ssooiill ssaammppllee rreessuullttss iinn tthhee W WWWTTPP aarreeaa aarree cCoOmlpnrpirisseedd ooff ssooiill ssaammpplleess collected during the insialation MW-105. Soil samples were colected and analyzed for collected during the installation MW-108. Soil samples were collected and analyzed for he four FC parameters (PERS, PEHS, PROS and PFOA) to assess he presence ofFCs in the four FC parameters (PFBS, PFHS, PFOS and PFOA) to assess the presence of FCs in Soil inthe WWTP are. Soil samples were collected fon the monitoring well boring 10 a soil in the WWTP area. Soil samples were collected from the monitoring well boring to a depth of 25 ft bs. depth of 25 ft bgs. TThhee PPhhaassee 22 ssooiill ssaammppllee rreessuulltts,, aas ssuummmmarairizzeedd iinn TTaabbllee 44--33,, iinnddiiccaattee tthhaatt FFCCss wweerree ddeetteecctteedd aatt MMWW--110088 aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..229955 ppppbb ((PPFFBBSS,, 2200--2255 ffeeeett))ttoo 223300 ob (PFOS, 5-10 fer) At the lowest interval sampled (20-25 fet), PFOA and PROS pWpebre(PdFeOteSi,ed5-1a0t tc'eoentc)e. nAtrtatthieonslowofes6t 0in4terpvpabl saanmd pl1e1d.3(2p0p-b25refespeetc),tiPveFlOy.A PaFnIdISPFwOaSs wdeetreectdedetaetctheed 2a0t-2c5onfceetntirnatteirovnals aotf c6o.0n4cepnpbtraantdoifo1n1.30.31p4ppbpb.resPpFeBctSivaelsy. nPotFHdeStecwteads dbeetleocwtetdheat1t5h-e2200f-2o5o fienetetrivnalt.ervTahleatPhaacsoenc2eonitrlatainoanlyotifc0a.l31re4suplptbs.aPrFeBprSesweanstendoot ndeFtiegcuterde 4below the 15-20 foot interval. The Phase 2 soil analytical results are presented on Figure 4-3. 44..33..55 FFiirree TTrraaiinniinngg AArreeaa 44..33..55..11 SoSiolil SSaammpplilinngg RReessuullttss TThhee PPhhaassee 22 ssooiill ssaammppllee rreessuultss iinn tthhe FFiirree TTrraaiinniinngg AArreeaa ((FFTTAA)) aarree ccoommpprriisseeddooffsosoiill Samples collected from 6 hand auger locations (FTA-04 through FTA-09). Samples were csoalmlepcletesdcforlloemct0e-d1 ffrtomand6 2h-a3ndfaatugeearchlolcoactaitoinosn (wFiTthAt-0he4 ethxrcoeupgihonFoTfAF-0T9A)G. 7Sawmheprleesawugeerer collected from 0-1 ft and 2-3 ft at each location with the exception of FTA07 where auger samples were coleted and analyzed for the rreeffuussaall wwaass eennccoouunntteerreedd aanndd aa ssaammppllee ccoouulldd twelve FC parameter. The FTA oonnllyy bbee ccoolllleecctteedd ffrroomm tthhee 00--11 sample ffit.. SSooiill lsoacmatpileonsswaevree pcroelsleecntteedd ainnd Faingaulryeze3d-2.forThthee Ptwhaesleve2FCsoilparsaammpelteerss.2sThseumFmTaArizsaemd plien Tlaobcalteio4n-s4 aarned pFriegsuernete6d iinndFicigaiueretha3t-2F.CsThweerPehadesetec2tedsoailt csoanmepelneisatasiosnurmamngairnizgefdroimn Table 4-4 and Figure 4-6 indicate that FCs were detected at concentrations ranging from 00..330066 ppppbb ((PPFFBBAA,, FFTTAA0088,, 00--11 1ft)) ttoo 22,,994488 ppppbb ((PPFFOOSS,, FFTTAA0,6, 2-3 feeeett)).. FTAO2, 0-6" depth, located in the drainage swale south of the FTA. This swale receives TThhee PPhhaassee 11 ssooiill ssaammppllee rreessuullttss iinnddiiccaattee aa PPFFOOSS ccoonncceennttrraattiioonn ooff 11,,882200 ppppbb aatt SSSS. FTA02, 0-6" depth, located in the drainage swale south of the FTA. This swale receives collection of the Phase 1 samples, this ara was re-graded and 3 rtenion basin was ssuurrffaaccee wwaatteerr ddrraaiinnaaggee ffrroomm tthhee FFTTAA aanndd ssuurrrroouunnddiinngg ccoonnttrraaccttoorr yyaarrdd aarreeaa. AAfftteerr tthhee collection of the Phase 1 samples, this area was re-graded and a retention basin was Confidential - 3M Insurance D--ocument"sih Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc 4-11 Confdential- 3M Insurance Documents 3MM_ENEVN_V0000000033115599 a3MW_mMNNo0r1a4s8s3o0s8s4 22116622..00008833 constructed to improve storm water management in the area. The storm water overflow ssttrruuccttuurree wwaass ccoonnssttrruucctteedd wwiitthh rriipp rraapp aatt tthhee llooccaattiioonn ooff tthhee SSSS FFTTAA0022 ssaammpplele.. TThhee PPhhaassee 22 ssaammpplleess ccoolllleecctteedd ffrroomm tthhiiss llooccaattiioonn ({FFTTAAO0S8)) iinnddiiccaatteedd aa PPFFOOSS ccoonncceennttrraattiioonn ooff 114455 ppppbb aatt tthhee 22--33 fftt ddeepptthh.. AA sseeccoonndd ssaammppllee wwaass ccoolllleecctteedd ffrroomm tthhee bboottttoomm ooff tthhee retention basin (FTA07) with a similar PFOS result of 144 ppb at the 0-1 ft bgs depth. A PFOS concentration of 2,948 ppb at FTA06 (2-3 ft bgs) was detected in the FTA during Phase 2. This sample ~vas collected from a drainage s~vale just south of the holding pond. During Phase 1, PFOS concentrations of 378 ppb and 863 ppb were found in the shallow interval of 0-5 ft at borings FTA02 and FTA03 respectively, with lower ccoonncceennttrraattiioonnss ((rraannggiinngg ffrroomm 11..3355 ppppbb ttoo 8822..22 ppppbb)) aatt lloowweerr ddeepptthh iinntteerrvvaallss.. 1T"hhee aarreeaa around FTA03 has also been substantially reworked with the construction of the retention basin. Phase 2 locations FTA04 and FTA05 were also located south of the holding pond in grassy swales that direct surface runoff from the FTA to the retention basin. Soil sample rreessuullttss iinnddiiccaattee PPFFOOSS ccoonncceennttrraattiioonnss iinn tthhiiss aarrecaa aarree ccoonnssiisstteenntt wwiitthh tthhee PPhhaassee 11 rreessuullttss collected from FTA02 and FTA03. PFOS concentrations from the 0-1 ft interval at FTA04 and FTA05 are 1,026 ppb and 458 ppb respectively. PFOS concentrations at the 2-3 ft bgs interval were NR. The other FC compounds, i.e., PFOA, PFHS and PFBA, indicate lower concentrations at the 2-3 ft interval showing a decrease in concentration with depth. A Phase 2 soil sample (FTA09) was collected at the edge of a concrete pad which is ccuurrrreennttllyy uusseedd ffoorr ffiirree ttrraaiinniinngg wwiitthhiinn tthhee FFTTAA.. AA ssaammppllee wwaass ccoolllleecctteedd ffrroomm tthhee 00--11 ffit depth. A deeper sample could not be obtained with the hand auger due to large gravel that was encountered. PFOS was detected at a concentration of 747 ppb. Other FC ws exsTavDWESTCOE compounds were detected at lower concentrations as indicated on Table 4-4. 4.4 EASTAND WEST COVES Activities associated with the Phase 2 FC Assessment conducted in the East and West Coves of the Cottage Grove Site occurred on September 13, 14, and 20, 2006. These Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntti ss4-]2 33MM_EENNVV_0000000033116600 3M MN01483085 22116622..00008844 activities were performed to address data gaps identified during the Phase 1 program in tthhee ccoovveess aanndd ccoonnssiisstteedd ooff pphhyyssiiccaall cchhaarraacctteerriizzaattiioonn,, ssuurrffaaccee wwaatteerr ssaammpplliinngg., aanndd sediment sampling. Results fom the Phase 1 program are summarized in Subsection 3.1. 44..44.11 EEaasstt CCoovvee Phase 2 assessment activities were conducted in the East Cove on September 13 and 14, 2006. Adjustments and/or clarifications to the field procedures implemented during cchhaarraacctteerriizzaattiioonn aanndd ssaammpplliinngg aaccttiivviittiieess iinn tthhee EEaasstt CCoovvee wweerree aass ffoolllloowwss:: A topographical map (Figure 4-7) depicting the boundaries of the East Cove was provided by 3M's civil engineering department. This map accurately rreeflleecctss tthhee EEaasstt CCoovvee,, as vveerriffiieedd inn tthhee ffiieelldd bby WWEESSTOON pperssoonnnneell,; tthheerreeffoorree,, tthhee ssuurrffaaccee aarreeaa ffoorr tthhee ccoovvee wwaass ccaallccuullaatteedd ffrroomm tthhiiss mmaapp aanndd nnoo. additional survey work was performed. In accordance with the approved Work Plan, surface water samples were ccoolllleecctteedd aatt tthhee ttwwoo llooccaattiioonnss ((EEaasstt CCoovvee ((EECC)) llooccaattiioonnss EECC--44 aanndd EECC--1111)),, identified in Figure 4-8, from the water surface and the 0.6 depth interval, rraatthheerr tthhaann tthhee wwaatteerr ssuurrffaaccee aanndd tthhee 00..22 aanndd 00..88 ddeepptthh iinntteerrvvaallss,, dduuce ttoo tthhee shallow water depth (measured to be less than 2 feet deep). * IInn aaccccoorrddaannccee wwiitthh tthhee aapppprroovveedd WWoorrkk PPllaann,, sseeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd from three distinct intervals (top, bottom, and mid core thickness) at six locations (EC-5 through EC-10), identified in Figure 4-9, within the cove. In addition, sediment samples were collected from one location (ECD-1) in a ttshehiidccikmknneeensssts ((dii..eee.p.ollseeisstss otthhuaatsnnid33effeeteehttetthhciiocckvk)e),, fssoaaommtppplrleeinsst.wweeDrreueeccootlollleetcchtteeedd sffhrroaolmmlowoonnllsyyetdthhieme tetoonppt and bottom interval s. The depth of the native alluvium could not be determined based on the core samples collected at all six locations within the East Cove footprint; therefore, samples representing the bottom interval were collected from within a distinct sediment stratigraphy observed in the field. This sampling interval deviated slightly from the carr psn crasnaton bottom sediment sampling interval identified in the Work Plan. 4.4.1. 1 Physical Characterization As depicted in Figures 3-3 and 4-7, the East Cove footprint is a 2 acre area that serves as tthhee tteerrmmiinnaattiioonn ppooiinntt ffoorara ddrraaiinnaaggeewwaayy llooccaatteedd ttoo tthhee ceaasstt ooff tthhee CCoottttaaggee GGrroovvee SSiittee.. IItt Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttessxt 4-]3 33MM_EENNVV_0000000033116611 3M MN01483086 22116622..00008855 sshhoouulldd bbee nnootteedd tthhaatt tthhiiss ffoooottpprriinntt vvaarriieess ssuubbjjeecctt ttoo iinnfflluuxxeess ooff ssuurrffaaccee wwaatteerr aanndd gsrroouunnddwwaatteerr iinnttoo tthhee EEaasstt CCoovvee;; tthheerreeffoorree tthhiiss aarreeaa iiss aapppprrooxxiimmataete.. TThhee ccoovvee aanndd tthhee aassssoocciiaatteedd ddrraaiinnaaggeewwaayy aarree llooccaatteedd iinnaa rraavviinnee ssuurrrroouunnddeedd bbyy aaddeennsseellyy wwooooddeedd aarreeaa.. TThhee ddrraaiinnaaggeewwaayy oorriiggiinnaatteess ffrroolrmi RRaavviinnee LLaakkee nnoorrtthh ooff UUS.S.. HHiigghhwwaayy 6611,, aanndd ffoolllloowwss aa ssoouutthheerrllyy ddiirreeccttiioonn uunntlil iitt aapppprrooaacchheess tthhee ppllaanntt ooppeerraattiioonnss aarreeaa wwhheerree iitt rreecceeiivveess tthhee NNPPDDEESS--ppeemrimtittteedd ddiisscchhaarrggee ffrroomm tthhee ppllaannt''ss wwaasstteewwaatteerr ttrreeaattmmeenntt aanndd ccoooolliinngg wwaatteerr ssyysstteemm.. TThhiiss ddiisscchhaarrggee wwaatteerr ccoommpprriisseess mmoosstt ooff tthhee ffllooww iinnttoo tthhee EEaasstt CCoovvee eexxcceepptt dduurriinngg ppeerriiooddss ooff hheeaavvyy rraaiinnffaallll wwhheenn ssuurrffaaccee rruunnooffff eenntteerrss tthhee rraavviinnee uuppggrraaddiieennttooff tthhee oouutftfaalll.l. TThhee ddrraaiinnaaggeewwaayy fflloowwss iinnttoo tthhee nnoorrtthhwweesstt ppoorrttiioonn ooff tthhee EEaasstt CCoovvee,, wwhheerree iitt ccoonnttiinnuueess aa sditsitinnctt ssoouutthheerrllyy ffllooww lliinnee ttootthhee ssoouutthhxwveesstt ppoorrttiioonn ooff tthhee ccoovvee.. TThhee oouuttlleett ooff tthhee EEaasstt CCoovvee,, llooccaatteedd iinn titss ssoouutthhwweesstt ccoormneerr,, tthheenn ddrraaiinnss uunnddeerraa rraaiillrrooaadd ttrreessttllee iinntoo tthhee MMisisssiissssiippppii RRiivveerr ddiirreeccttllyy ddoowwnnssttrreeaammoofftthhee CCoottttaaggeeGGrroovvee SSiittee. SSuurrffaaccee WWaatteerr OObbsseerrvvaattiioonnss AAss ppaarrtt ooff tthhee PPhhaassee 22 aasssseessssmmeenntt aaccttiivviittiieess,, ssuurrffaaccee wwaatteerr ssaammpplliinngg wwaass ccoonndduucctteedd ffrroomm aa ttoottaall ooff ttwwoo llooccaattiioonnss,, aass ddeeppiicctteedd iinn FFiigguurree 44--88.. LLooccaattiioonn EECC--44 wwaass ppoossiittiioonneedd mmiiddcchhaannnneell iinn tthhee iinnlleett aanndd uuppssttrreeaammooff tthhee EEaasstt CCoovvee,, wwhhiillee EECC--1111 wwaass ppoossiittiioonneedd mmiidd-cChhaannnneell iinn tthhee oouuttlleett ttoo tthhee MMiissssiissssiippppii RRiivveerr.. AAss pprreevviioouussllyy mmeennttiioonneedd~. wwaatteerr ddeepptthh aatt tthheessee ssaammpplliinngg llooccaattiioonnss wwaass oobbsseerrvveedd ttoo bbee sshhaallllooww,, mmeeaassuurriinngg 11..1177fft aatt iinnlleett llooccaattiioonn EECC--44 aanndd 00..6677 fftt aatt oouuttlleett llooccaattiioonn EECC-1-11.1. SSuurrffaaccee wwaatteerr ssaammpplleess wweerree ccoolllleecctteedd aatt tthhee wWaatteerr ssuurrffaaccee aanndd aatttthhee006.6 ddeepptthh iinntteerrvvaall aatt bbootthh llooccaattiioonnss. WWaatteerr qquuaalliittyy iinn tthhee EEaasstt CCoovvee wwaass oobbsseerrvveedd ttoo bbee cclleeaarr aanndd ccoolloorrlleessss,, wwiitthh aa sstteeaaddyy rraattee ooff ssuurrffaaccee wwaatteerr fNlooww ooccccuurrriinngg ffii-oomm tthhee ddrraaiinnaaggeewwaayy iinn aa ssoouutthheerrllyy ddiirreeccttiioonn ttoowwaarrddss tthhee ccoovvee oouutltleet.t. MMeeaassuurreemmeennttss ooff tthhee wwaatteerr vveelloocciittyy ccoolllleecctteedd dduurriinngg tthhee PPhhaassee 22 aaccttiivviittiieess,, aass ddeeppiicctteedd iinn FFiigguurree 44--77,, iinnddiiccaatteedd tthhaatt ssuurrffaaccee wwaatteerr fflloowweedd ffrioomm tthhee ddrraaiinnaaggeewwaayy iinnttoo tthhee EFaasstt CCoovvee aatt aa rraatee ooff aapppprrooxxiimmaatteellyy 22..77 ffeeeett ppeerr sseeccoonndd ((fft/sseecc)). T"Thhiiss vveelloocciittyy wwaass oobbsseerrvveedd ttoo ddeeccrreeaasseettoo. a rraatteeooffaapppprrooxxiimmaatteellyy 11. .1fifts/seecc aatttthheeccoovvee''ss oouuttlleett iinnttoo tthhee MMisisssiissssiippppii RRiivveerr.. nm mr Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-]4 22116622..00008866 33MM_EENNVV_0000000033116622 S3MM_MMNNO011448833008877 SSeeddiimmeenntt OObbsseerrvvaattiioonnss AAss ppaarrtt ooff tthhee PPhhaassee 22 aasssseessssmmeenntt aaccttiivviittieess,, sseeddiimmeenntt ssaammpplliinngg wwaass ccoonndduucctteedd Ffrioomm aa ttoottaall ooff ssiixx llooccaattiioonnss ((EECC--5S tthhrroouugghh EECC--1100)) wwiitthhiinn tthhee EEaasstt CCoovvee ffoooottpprriinntt eanndd oonnee llooccaattiioonn ((EECCDD-0-01)1)ffrroomm aa sseeddiimmeenntt ddeeppoossiitt iimmmmeeddiiaattellyy oouuttssiiddee tthhee EEaasstt CCoovvee ddiisscchhaarrggee,, aass ddeeppiicctteedd iinn FFiigguurree 44--99.. TThhee ssiixx EEaasstt CCoovvee ssaammpplliinngg llooccaattiioonnss wweerree ppoossiittiioonneedd aass iiddeennttiiffiieedd bbeellooww: + ECEECCS--:65.:annndoorrEttChh-ww7e:esstttpprooarrnttsiieoocnnt ooafcfrttohhseescctoohvveeenaoattrtiihnnelleeatsttaaddpjjoaarccieeonntntot0fottthhheee ffcllooowvwelliinnee ++ EEEECCCC.--:986::aannssddoouuEEttChCh-ww-1e7e0s::stttpprtaoornrrattsniiesoocenntcotoafcafrcttorhhsoeessscctohotvveheeenaaosbborutoohtvveheeeaasoostuuttptllopeertottriaaoinnnoddnoaaofddfjtjhaateccheeecnnocttvottevoofefllooww lliinnee EC-9 and EC-10: transect across the southeast portion of the cove IInn aaddddiittiioonn ttoo tthhee ssiixx ssaammpplliinngg ppooiinnttss,, ffoouurr ootthheerr llooccaattiioonnss wweerree pprroobbeedd wwiitthh tthhee cclleeaarr ppoollyyccaarrbboonnaattee ttuubbeess ffoorr vviissuuaall oobbsseerrvvaattiioonn aanndd llooggggiinngg: + ECSW . EEEECCCC--5UUUW1 + EECC-UUS2 EC-U3 SSeeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd ffrroomm eeaacchh ooff tthhee ssiixx EEaasstt CCoovvee llooccaattiioonnss rreepprreesseennttiinngg tthhee ttoopp., mmiidd,, aanndd bboottoomm iinntteerrvvaallss ooff tthhee oobbsseerrvveedd sseeddiimmeenntt tthhiicckknneessss.. W Whhiillee tthhee ttoopp interval at each location represented a consistent depth interval (0 to 6 inches below the interval at each location represented a consistent depth interval (0 to 6 inches below the ttoopp ooff sseeddiimmeenntt)),, tthhee mmiidd aanndd bboottttoomm iinntteerrvvaallss vvaarriieedd iinn ddeepptthhss.. OObbsseerrvvaattiioonnss ooff tthhee sedimentcoresindicated the presenceofthree distinct sediment layers as follows: sediment cores indicated the presence of three distinct sediment layers as follows: + TToopp:: ttaann//bbrroowwnn ttoo bbllaacckk,, ssaanndd ttoo ssiillttyy ssaanndd,, ttiigghhtt ccoonnssiisstteennccyy. MiMldiig:dh:tldodoaasrrekk ecgornyesyistttooenbbcllyaa.cckkN((onntooenn--n--naatttihivviese)),l,affyiiennree rssaillntyygelldaayyfeerrrowwmiitt2hh issnoocmmheeesccltlaoayy2ccoofnentetetenntit,n, tlihihgiichcktk/nnloeeossssseddeecppoeennnsddiesetnnetnt cuuypp.oonnNossaatemmpp-lleethllioosccaalttaiiyooennr. ranged from 2 inches to 2 feet in = BcBoootnttstooimsm:t:encbbyllaawccikkth((nndooennp--tnnhaattiivvee)) ttoo ggrreeyy,, ssaanndd aanndd ssiillttyy ccllaayy,, mmoottlteledd,, ssoofftt tto ttiigghhtt consistency with depth. AA ppeettrorloeluemu-ilikkee ooddoorr aanndd ddiissccoolloorraattiioonn wwaass nnootteedd wwhhiicchh pprriimmaarriillyy ooccccuurrrreedd iinn tthhee mmiidd aanndd bboottttoomm ssaammpplliinngg iinntteerrvvaallss aatt eeaacchh llooccaattiioonn wwiitthh tthhee eexxcceeppttiioonnooff llooccaattiioonnss EECC--UUZ2 aanndd EECC-UU.3. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc om "ais4-15 Confidential - 3M IInnssuurraannccee DDooccuummeennttss Confdential- 3M 22116622..00008877 33MM_EENNVV_0000000033116633 S3MM_MMNNO011448833008888 AAss nnootteedd aabboovvee,, tthhee mmiidd llaayyeerr ooff tthhee sseeddiimmeenntt ccoorreess eexxthiibbiitteedd lloooossee,, sseemmii--ssoolliidd ccoonnssiisstteennccyy.. TThhiiss llaayyeerr vvaarriieedd iinn ddeepptthh aanndd tthhiicckknneessss aatt ceaacchh ssaammppllee llooccaattiioonn,, aappppeeaarriinngg to have been deposited in pockets throughout the cove Toor. Up to 2.foot hick tdoepohsaivtes boefetnhisdempaotseirtieadl iwnerpeocokbestesrvtherdouinghtohuetmtihde lcaoyveer ofofotthperincto.reUpsamtople2s-focootlltchticekd doempostithse oFafstthiCsovmeasteerimalenwere observed in the mid layer of the core samples collected from the East Cove sediment. LLooccaattiioonn EECCDD--0011 wwaass ppoossiittiioonneedd ddiirreescttllyy ddoowwnnssitrzeeaamm ooff tthhee oouuttlleett nin a sseeddiimmeenntt ddeeppoossiitt aalloonngg tthhee nnoorrtthh bbaannkk ooff tthhee MMiissssiissssiipppii RRiivveerr.. TThhee sseeddiimmeenntt ccoorree wweass oonnllyy aabblee ttoo bbee aaddvvaanncceedd 1to0 a ttoottaall ddeepptthh ooff 1144 iinncchheess ffrroomm tthhee t1o0p ooff sseeddiimmeennt.t. SSeeddiimmeenntt ccollllecctteedd aatt tthhiiss llooccaattiioonn ccoonnssiisstteedd ooff oonnee llaayyeerr,, aa ttaann aanndd bblaacckk ssaanndd,, tthhrroouugghhoouutt tthhee ccoorree.. SSeeddiimmeenntt observed sediment thickness. ssaammpplleess wweerree ccoolllleecctteedd ffrroomm tthhisisloloccaattiioonn rreepprreesseennttiinngg tthhee ttoopp aanndd bboottttoomm iinntteerrvvaallss oofftthhee observed sediment thickness. 44.44.. 14.22 SSuurrtfaaccee WWaateterr SSaammpplliinnggRReessuuilttss The FC resus for the surface water samples collcted from the Fast Cove are TSuhmemaFrCizeredsuinltsTafbolre t4h-5e. The FC surface wanaatleyrticsaalmrpelseusltscoslulemcmtaerdizferodmin tThaeblEea4st5Cionvcleudaerse PsuFmOAm,arPizFeOdS,inPTRaBbSl,e P4F-5H.S,ThaendFCPFaBnAa.lyAticcaol mrpelseutltes dsautma msuamrimzaedryintaTblaeblienc4l-u5diinngclaulde1s2: PFFCOcAo,mpPoFuOnSd,sPiFBprSo,vPiFdeHdSi,naAnpdpPeFndBiAx. A complete data summary table including all 12 FC compounds is provided in Appendix D. FFiigguurree 44--88 ddeeppiiccttss tthhee PPFFOOAA,, PPFFOOSS aanndd PPFFBBAA ssuurrffaaccee wwaatteerr ccoonncceenntrtraattiioonnss.. NNoo ssiiggnniiffiiccaanntt ccoonncceennttrraattiioonn ddiiffffeerreenncceess wweerree ffoouunndd ffoorr ddeetteecctteedd FFCCss iinn ssaammpplleess collected from the inlet location EC-4 and the ult location EC-11. In addon, no collected from the inlet location EC-4 and the outlet location EC-11. In addition, no ssiiggnniiffiiccaanntt ccoonncceennttrraattiioonn ddiiffffeerreenncceess wweerree ffoouunndd ffoorr ddeetteecctteedd FFCCss iinn ssaammpplleess ccoolllleecctteedd from the water surf and the 0.6 depth interval. The following is a summary of the from the water surface and the 0.6 depth interval. The following is a summary of the ange ofaverage concentrations for the five key compounds range of average concentrations for the five key compounds: PBS: + PPFRBHSS: 994.10111311to004995.66899pppppbbb. + + PPFRHOSS: PPFFOOSA: 4112..011235511ttoo013430.1.513823ppp7ppppb9bbb + PPRFBOAA': NR2.21 to 2.79ppb PFBA: NR Confidential - 3M Insurance D--ocument"sio Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc 4-16 Confdential- 3M Insurance Documents 22116622..00008888 33MM_EENNVV_0000000033116644 W3M_MNMON104184833008809 Due to laboratory QC issues, the analytical results for PFBA were NR for all surface wwaatteerr ssaammpplleess ccoolllleecctteedd ffrroomm llooccaattiioonnss EECC--44 aanndd EECC-1-11.1. AAnn aaddddiittiioonnaall FFCC ccoommppoouunndd detected in the surf'ace water samples at notable average concentrations was PFPeA, wars oamenrsamming esas which ranged from 9.32 to 9.75 ppb. 4. 4. I. 3 Sediment Sampling Resu/ts er The FC results for the sediment samples collected from the East Cove are summarized in Table 4-6. TThhee FFCC aannaallyyttiiccaall rreessuullttss ssuummmmarariizzeedd iinn TTaabbllee 44--66 iinncclluuddeess:: PPFFOOAA,, PPFFOOSS,, PPFFBBSS,, PPFFHHSS and PFBA. A complete data summary table including all 12 FC compounds is provided in Appendix D. Figure 4-9 depicts the PFOA, PFOS and PFBA concentrations. TThhee ffoolllloowwiinngg is a ssuummmlnaarry of tthhe rraanngge of average coonncceennttrraattiioons ffoor tthhe fiivve keyy compounds for the top, mid, and bottom sediment layers sampled within the footprint of tthhee EEaasstt CCoovvee ((EECC--5 tthhrroouuggh EECC--1100)):: PFOS: Interval top layer: mid layer: bottom layer: PFOA: top layer: mid layer: bottom layer: PFBA: top layer: mmiidd llaayyeerr:: bottom layer: PFHS: top layer: mid layer: bottom layer: PFBS: top layer: mid layer: bottom layer: Within East Cove 40 to 1,145 ppb 1,985 to 65,450 ppb 2,850 to 9,150 ppb 7.90 to 88.6 ppb 31.2 to 996 ppb 0.764 to 1845 ppb 16.3 to 24.8 ppb 66..0055 t1o09944..66 ppppbb. ND to 30.8 ppb 1.13 to 7.87 ppb 3.24 to 126 ppb ND to 51.6 ppb 2.29 to 18.4 ppb 0.828 to 9.14 ppb ND to 2.03 ppb Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RepomFinal Phase 2 R=.port doc or = 4-17 Confidential - 3M IInnssuurraannccee DDooccuummeennttss Confdential ~ 3M 33MM_EENNVV_0000000033116655 3M MN01483090 22116622..00008899 IInn tthhee ttoopp sseeddiimmeenntt llaayyeerr,, tthhee hhiigghheesstt ccoonncceennttrraattiioonnss ooff FFCCss wweerree ddeetteecctteedd aatt llooccaattiioonnss EECC--88,, EECC--99,, aanndd EECC--1100 iinn tthhee ssoouutthheerrnn ppoorrttiioonn ooff tthhee EEaasstt CCoovvee.. TThhee lloowweesstt ccoonncceennttrraattiioonnss ooff FFCCss iinn tthhee ttoopp sseeddiimmeenntt llaayyeerr wweerree ddeetteecctteedd aatt llooccaattiioonnss EECC--55 aanndd EECC-66., iinn tthhee nnoorrtthhwweesstt ppoorrttiioonnoofftthhee ccoovvee.. AAnn eexxcceeppttiioonn ttoo tthhiiss iiss llooccaattiioonn EECC--77,, iinn tthhee nnoorrtthheeaasstt ccoormneerr ooff tthhee ccoovvee,, wwhhiicchh eexxhhiibbiitteedd tthhee lloowweesstt PPFFOOAA ccoonncceennttrraattiioonn aanndd hhiigghheesstt PPFFOOSS ccoonncceennttrraattiioonn ddeetteecctteedd iinn tthhee ttoopp sseeddiimmeenntt llaayyeerr.. IInn tthhee mmiidd sseeddiimmeenntt llaayyeerr,, tthhee hhiigghheesstt ccoonncceennttrraattiioonnss ooff FFCCss wweerree ddeetteecctteedd aatt llooccaattiioonnss EECC--5$ aanndd EECCS-8,, iinn tthhee wweesstteerrnn ppoorrttiioonnoofftthhee EEaasstt CCoovvee,, aanndd EECC--1100,, iinn tthhee ssoouutthheeaasstt ccoormneerroofftthhee EEaasstt CCoovvee..TThheelloowweesstt ccoonncceennttrraattiioonnss ooff FFCCss iinn tthhee mmiidd sseeddiimmeenntt llaayyeerr wweerree aallll ddeetteecctteedd aatt llooccaattiioonn EECC--T7,, iinn tthhee nnoorrtthheeaasstt ccoormneerrooff tthheeccoovvee.. IInntthhee bboottttoomm sseeddiimmeenntt llaayyeerr,, tthhee hhiigghheesstt ccoonncecnetrnattironastooiffoFFnCCss wweerree ddeetteecctteedd aatt llooccaattiioonnss EECC--55,, EECCS-8,, aanndd EECC--9iinn tthhee wweesstteermn ppoorrttiioonnofotf thhee EEaasstt CCoovvee.. TThhee lloowweesstt ccoonncceennttrraattiioonnss oofff FFCCss iinn tthhee bboottttoomm sseeddiimmeenntt llaayyeerr wweerree ddeetteecctteedd aatt llooccaattiioonn EECC--77 aanndd EECC--1100,, iinn tthhee ecaasstteerrn ppoorrttiioonn ooff tthhee ccoovvee.. AAnn eexxcceeppttiioonn ttoo tthhiiss iiss aa NNDD rreessuulltt ffoorr PPFFBSS aatt llooccaattiioonn EECC-s5. IItt sshhoouulldd bbee nnootteedd tthhaatt tthhee sseeddiimmeenntt tthhiicckknneessss ccoolllleecctteedd ffrroomm llooccaattiioonn EECCDD--1111 mmeeaassuurreedd oonnllyy 1144 iinncchheess.. IIt ccoonnssiisstteedd ooff mmaatteerriiaall ssiimmiillaarr t1o0 tthhee ttoopp sseeddiimmeenntt llaayyeerr oobbsseerrvveedd iinn tthhee EEaasstt CCoovvee.. TThhee ffoolllloowwiinngg iiss aa ssuummmmaarryy ooff aavveerraaggee ccoonncceennttrraattiioonnss ffoorr tthhee ffiivvee FFCC ccoommppoouunnddss ffoorr tthhee ttoopp aanndd bboottttoomm sseeddiimmeenntt ssaammpplleess ccoolllleecctteedd ddiirreeccttllyy ddoowwnnssttrreeaamm tthhee EEaasstt CCoovvee oouuttlleett ((EECCDD--1111)):: PPFFOOSS:: PPFFOOAA:: PPFFBBAA.: PPFHHS:S: PPFFBBSS:: IInntteerrvvaall ttboooppttssoaammmpsplaelem::ple: bottom sample: tbtoooppttssoaammmpsplaelem::ple: bottom sample: ttboooppttssoaammmpsplaelem::ple: bottom sample: ttboooppttssoaammmpsplaleme:ple: bottom sample: ttboooppttssoaammmpsplaele:m:ple bottom sample: OuOtustisiddeeFEasatst Cove Cove NN63RR6 ppb. 63.6 ppb 22166.15.35 ppppppbbb. 11.3 ppb 711.550.444 ppppppbbb 7.04 ppb 111.177199 ppppppbbb. 1.11 ppb 022..2281127pppppbpb.b. 0.827 ppb (ECD-11 (ECD-11) ama Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment RegomFinal Phase 2 Report doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-18 33MM_EENNVV_0000000033116666 33MM_MMNNO011448833009911 22116622..00009900 In the top and bottom sediment samples of location ECD-11, FC concentrations were eciitthheerr ccoommppaarraabbllee oorr lloowweerr tthhaann tthhoossee ddeetteecctteedd wwiitthhiinn tthhee EEaasstt CCoovvee ffoooottpprriinnt.t. DDuuee ttoo llaabboorraattoorryy QQCC iissssuueess,, tthhee aannaallyyttiiccaall rreessuullttss ffoorr PPFFOOSS wweerree NNRR ffoorr tthhee ttoopp sseeddiimmeenntt sample collected at location ECD-11. sixteen 4.4.2 West Cove 4. 4.2. 1 Physical Description The topography in the area of the West Cove and the surveyed boundaries are presented in Figure 4-10. The West Cove is approximately one acre. Water flows intermittently into the cove from surface drainage tYom the Cottage Grove plant from the north and east and ffrroomm tthhee mmuunniciciippaall wwaasstteewwaatteerr ttrreeaattmmeenntt ppllaanntt ttoo tthhee wweesstt.. WWaatteerr ddiisscchhaarrggeess tthhrroouugghh aa concrete culvert beneath the railroad tracks at the southeast corner of the cove. At the time of sampling there was no noticeable flow of water into the cove, however water was discharging through the culvert at approximately 13.5 ft/sec. (measured at surface water sampling location WC08). The water level elevation in the cove is indicative of basal groundwater flow. Except during periods of heavy rainfall the water in the cove is still, with heavy algal growth in the summer. Water depths in the cove range from approximately 3 feet at southern edge (WC08) to less than 1 foot to the north (WC04). DDuurriinngg sseeddiimmeenntt ssaammppllee ccoolllleeccttiioonn vviissuuaall ddeessccrriippttiioonnss ooff sseeddiimmeenntt wweerree rreeccoorrddeedd aatt eeaacchh location using clear polycarbonate tubes. The sediments throughout the cove are very soft and loose and are represented by three horizons. Black organic rich silt is present ranging in thickness from 6 to 12 inches. A layer of light to dark gray sticky clay underlies the silt llaayyeerr rraannggiinngg iinn tthhiicckknneessss ffrroomm 1166 ttoo 1199 iinncchheess.. BBeenneeaatthh tthhee ccllaayy llaayyeerr iiss aa ddaarrkk bbrroowwnn ttoo black clayey silt layer. This silt layer was encountered at location WC06 at 22 to 30 inches below the surface of the sediment. The total thickness of this silt layer could not be determined with the polycarbonate tubes. Based on the descriptions of the sediment cores at the sampling locations, the sediments in the West Cove appear to be native sediments and do not exhibit JE representative of waste material (i.e., ash, tars, odors or sheen). Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-]9 any characteristics 33MM_EENNVV_0000000033116677 3M MN01483092 22116622..00009911 44.44.22.22 SSuurrffaaccee WWaatteerr SSaammpplliinnggRReessuullttss SSuurrffaaccee wwaatteerr ssaammpplleess wweerree ccoolllleecctteedd ffrroomm ttwwoo llooccaattiioonnss aatt tthhee W Weesstt CCoovvee.. OOnnee llooccaattiioonn., WC, WC-4, iiss iinn tthhee nnoorrtthheerrnn eenndd oof tthhee ccoovvee ((uuppggrraaddieientn)t)aanndd tthhee ootthheerr llooccaattiioonn,, W WCC--S8,, iiss aatt the southeastern comer where the water from the West Cove discharges beneath the the southeastern corner where the water from the West Cove discharges beneath the rraaiillrrooaadd ttoo tthhee M Misisssiissssiippppii RRiivveerr.. AAtt W WCC--44,, ssaammpplleess wweerree ccoolllleecctteedd aatt tthhee wwaatteerr ssuurrffaaccee and 05 feet deep. The samples from WC-8 were collected at the water surface, 0.5 t and and 0.5 feet deep. The samples from WC-8 were collected at the water surface, 0.5 ft and 22 f11t ddeeeepp,, aass ddeeffiinneedd iinn tthhee W Woorrkk PPllaann.. TThhee rreessuullttss aarree ssuummmmarariizzeedd iinn TTaabbllee 44--77 aanndd Figure 4-11 Figure 4-11. TThhee FFCC aannaallyyssiiss ffrroomm WWCC--44 iinnddiiccaatteess tthhaatt PPFROOSS ccoonncceennttrraattiioonnss ooff 11.0033 ppppbb ((wwaatteerr ssuurrffaaccee)) aanndd 11.77 ppppbb PPFFOOSS ((00.5.5 )ft) wweerree ddeetteecctteedd.. PPFFIBBAA wwaass ddeetteecctteedd aattaa ccoonncceennttrraattiioonn ooff 00.332255 ppppbb ((wwaatteerr ssuurrffaaccee)) aanndd NNRR ((00.5.5 f0t,). PPFFOOAA wwaass ddeetteecctteedd aatt ccoonncceennttrraattiioonnss ooff0.20.42400 pPpPb ((wwaatteerr ssuurrffaaccee)) aanndd 00..228844 ppppbb ((00..55 fft)).. TThhee PPhhaassee 11 ssuurrffaaccee wwaatteerr ssaammppllee ((WWCC--11)) iinnddiiccaatteedd PPFFOOSS aatt aaccoonncecnetnrtraattiioonn ooff1.12277ppppbbaanndd PPFFOOAA aatt00..669944 ppppbb.. AAtt llooccaattiioonn WWCC-8-8., PPFFBBAA wwaass ddeetteecctteedd aatt 11.0011 ppppbb ((00..55 f1t)) 00..880033 ppppbb ((22 f1t)).. TThhee wwaatteerr ssuurrffaaccee ssaammppllee wwaass NNRi.l. PPFFOOSS wwaass ddeetteecctteedd aait ccoonncceennttrraattiioonnss ootf" 00.224411 ppppbb ((wwaatteerr ssuurrffaaccee)),, 00..222277 ppppbb ((00..55 f1t)) aanndd NNRR aatt 22 ffeeet.t. PPFROOSS wwaass ddeetteecctteedd aatt WWCC--88 wwiitthh ccoonncceennttrraattiioonnss ooff0.20.42411 ppppbb ((wwaatteerr ssuurrffaaccee)) aanndd 00..222277 pPpb 0(0.551f)t).. 44..44.22.33 SSeeddiimmeennttSSaammplpilinngg RReessuullttss TThhee WWeesstt CCoovvee sseeddiimmeenntt ssaammpplliinngg rreessuullttss iinnddiiccaattee tthhee ddeetteeccttiioonn ooff FFCCss aatt eeaacchhoofftthhee 33 PPhhaassee 22 ssaammpplliinngg llooccaattiioonnss.. TThhee rreessuullttss aarree ssuummmmarariizzeedd iinn TTaabbllee 44--88.. FFiigguurree 44--1122 pprreesseennttss tthhee ssaammppllee llooccaattiioonnss aanndd aannaallyyttiiccaall rreessuullttss ooff tthhrreeee FFCC ccoommppoouunnddss ((PPFFOOSS,, PPFFOOAA aanndd PPFFBBAA)) wwhhiicchh wweerree ddeetteesctteedd aatt hhiigghheerr ccoonncceennttrraattiioonnss tthhaann tthhee ootthheerr FFCC rreessuullttss. TThheessee FFCC ddeetteeccttiioonnss rraannggee ffrroomm 44..55 ppppbb ooff PPFFBBAA aatt llooccaattiioonn WWCC00S5 ((00--66 iinncchh ddeepptthh)) ttoo 113377 ppppbbooff PPFFOOSS aatt llooccaattiioonn WWCCO077 ((1122--1188 iinncchh ddeepptthh).). WWiitthh tthhee eexxcceeppttiioonn ooff PPFFOOS,, tthhee rreessuullttss ooff tthhee ootthheerr FFCC ccoommppoouunnddss ddeetteecctteedd aarree ccoonnssiisstteenntt wwiitthh ddeepptthh.. PPFFOOSS ccoonncceennttrraattiioonnss ddeetteecctteedd aatt eeaacchh ooff tthhee 33 ssaammppllee llooccaattiioonnss aarree sslliigghhttllyy hhiigghheerr iinn tthhee Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc om "320 4-20 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 22116622..00009922 33MM_EENNVV_0000000033116688 SM_MNO1483083 3M MN01483093 subsurface sample compared to the surficial sample (0-6 inch sample depth). At locations W'WCC0055 aanndd WWCC0066 tthhee ssuubbssuurrffaaccee ssaammppllee wwaass ccoolllleecctteedd aatt aa ddeepptthh ooff 66--1122 iinncchheess.. TThhee subsurface sample at WC07 was collected at a depth of 12-18 inches. The PFOS concentration at the 12-18 inch depth was 137 ppb which is consistent with the 6-12 inch depth interval at location WC05 (126 ppb/108 ppb duplicate) and WC06 (133 ppb). PFOA concentrations range from 11.2 ppb at location WC06 (0-6 inches) to 15.9 ppb at location WC07 (0-6 inches). 44..55 MMIISSSSIISSSSIIPPPPII RRIIVVEERR SSAAMMPPLLIINNGG RREESSUULLTTSS The Mississippi River FC assessment is an extensive sampling program comprised of sample collection over approximately 40 miles of the river at locations upstream, addjjacenntt ttoo and dowwnn sttrreeaamm of tthhe CCoottttage GGrrove SSiittee.. TThhe ttyyppeess ooff ssaammpplleess ccoolllleecctteedd are described below: Porewater: Samples were collected (using a screened well point inserted 6-12 inches into the sediment) to assess possible groundwater discharge from the facility through bottom sediments and into the river. In addition to the porewater samples, sediment and surface water samples were collected at each of these locations. 43 locations were sampled. Transects: Surface water and sediment samples were collected to assess the spatial distribution of FCs along three transects across the river in the immediate vicinity of the facility. 13 locations were sampled. Longitudinal: Surface water and sediment samples (referred to as longitudinal samples) wweerree aallssoo ccoolllleecctteedd ttoo aasssseessss tthhee pprreesseennccee oorr aabbsseennccee ooff FFCCss iinn tthhee rriivveerr aatt llooccaattiioonnss upstream, adjacent and downstream of the facility to Lake Pepin. 17 locations were sampled. DDuurriinngg tthhee PPhhaassee 1| aasssseessssmmeenntt,, ssuurrffaaccee wwaatteerr aanndd sseeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd aanndd analyzed from six locations in the Mississippi River. Porewater samples were not Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttiss=] 4-21 22116622..00009933 33MM_EENNVV_0000000033116699 3M MN01483094 collected during the Phase 1 assessment. The Phase I samples were analyzed for ['our FC parameters. AAllll PPhhaassee 22 MMiissssiissssiippppii RRiivveerr ssaammpplleesswweerree aannaallyyzzeedd ffoorr tthhee 1122 FFCC ppaarraammeetteerrss aatt EExxyyggeenn Laboratories, 44..55..11 PPoorreewwaatteerr LLooccaattiioonnss 44.. 55.. 1I..11 PPoorreewwaatteerrSSaammplpilinngg RReessuullttss TThhee rreessuullttssoofftthhee ppoorreewwaatteerr ssaammpplliinngg iinnddiiccaattee tthhaatt FFCCss wweerree ddeetteecctteedd aattaa nnuummbbeerrooff nneeaarr sshhoorree llooccaattiioonnss iinn tthhee vviicciinniittyy ooff tthhee CCoottttaaggee GGrrove SSiittee., The poorrewwaatteerr sammpplliinng locations are presented in Figure 3-6. A summary of the analytical results are presented in Table 4-9. The results of the analyses for PFOS~ PFOA and PFBA are presented in Figures 4-13 to 4-15. The higher concentrations of these FCs were detected in three specific areas of the river. The IW-14 transect (WWTP area), the IW-19 transect (D1/D2 area) and IW-23 to IW-25 ((EEaasstt CCoovvee aarreeaa)) PFOS: A PFOS concentration of 206 ppb was detected at IW-25 located just downstream ooff tthhee mmoouutthh ooff tthhee EEaasstt CCoovvee ((FFiigguurree 44--1133)).. LLoowweerr ccoonncceennttrraattiioonnss ooff PPFFOOSS wweerree aallssoo ddeetteecctteedd uuppssttrreeaamm ooff tthhee mmoouutthh ooff tthhee CCoovvee aatt IIWW--2233 ((1155 ppppbb)) aanndd IIWW--2222 ((22..44 ppppbb).). IInn the area of IW-19, off-shore from the D1/D2 area, the higher concentrations of PFOS were detected closest to the shore at lW-19a (47 ppb) and IW-19b (53.1 ppb). IW-19 was NNRR.. AAlloonngg tthhee ITWW--1199 ttrraannsseecctt ppeerrppeennddiiccuullaarr ttoo tthhee sshhoorreelliinnee;; PPFFOOSS wwaass ddeetteecctteedd aatt aa concentration of 1.71 ppb at IW-19f, (500 feet from the shore). In the area of IW-14, offshore from the WWTP, the higher concentrations of PFOS were detected at lW-14a (31.3 ppppbb)),, lIWW--1144bb ((1122..22 ppppbb)) aanndd IIWW--1144 ((1122..44 ppppbb).). AA ccoonncceennttrraattiioonnooff 00..00552222 ppppbb wwaass detected at IW-14e. PFOS was not detected or was NR at the other locations along the IW-14 transect fhrther from shore. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttiss n 4-22 22116622..00009944 33MM_EENNVV_0000000033117700 3M MN01483095 LLoowweerr ccoonncceennttrraattiioonnss ooff PPFFOOSS wweerree ddeetteecctteedd aalloonngg tthhee lTWW--99 ttrraannsseecctt wwhheerree tthhee hhiigghheesstt ccoonncceennttrraattiioonnooff22..6699 ppppbl wwaass ddeetteecctteedd cclloosseesstt ttoo sshhoorree aatt IIWW--99aa.. DDeetteeccttiioonnss aatt ootthheerr llooccaattiioonnss aalloonngg tthhee FIWW--9 ttrraannsseecctt rraannggeedd ffrormom0.00.2072788 ppppbb ((IIWW--99e)) ttoo 11..0099 ppppbb ((IIWW--99)).. PPFEOOSS wwaass aalssoo ddeetteecctteedd aatt llooww ccoonncceennttrraattiioonnss aatt aanndd ddoowwnn ssttreeaammooff tthhee WWeesstt CCoovvee aatt llooccaattiioonnss 1IWW--11 ttoo IIWW--8S rraannggiinngg iinn ccoonncceennttrraattiioonn ffrroomm 00..00227700 ppppbb ((IIWW--88)) ttoo 00..665522 ppppbb aw-2) (rW-2). PPFFOOAA:: PPFFOOAA wwaass ddeetteecctteedd iinn ppoorreewwaatteerr ssaammpplleess ccoolllleecctteedd ffrroomm I1WW--2244 ((775588 ppppbb)), llooccaatteedd uupp ssttrreeaammooff tthhee mmoouutthh ooff tthhee EFaasstt CCoovvee aanndd ffrroomm IIWW--1144aa ((669999 ppppbb)) nneeaarr tthhee WWWWTTPP ((FFiigguurree 44--1144)).. PPFFOOAA wwaass aallssoo ddeetteecctteedd nneeaarr tthhee EEaasstt CCoovvee aatt ddoowwnn rstereaamm lTooccaattiioonn lIWW--2255 ((112299 ppppbb)) aanndd uuppssttrreeaammooff tthhee mmoouutthhooff tthhee CCoovvee aatt IIWW--2233 ((7788..66 ppppbb)).. IInn tthhee aarreeaa ooff IIWW--1199,, nneeaarr tthhee DDIl//DD?22 aarreea,, tthhe hhiigghheerr ccoonncceennttrraattiioonnss ooff PPFFOOAA wweerree ddeetteecctteedd cclloosseesstt ttoo tthhee sshhoorree aatt IIWW--1199bb ((111188 ppppbb)),, IIWW--1199 ((2288.99 ppppbb)) aanndd IIWW--1199c ((3344.33 ppppbb)).. AAtt llooccaattiioonnss ffaarrtthheerr ffrroomm sshhoorree aalloonngg tthhee IIWW--1109 ttrraannsseecctt,, ccoonncceennttrraattiioonnss rraannggeedd ffrioomm 00..118844 ppppbb ((IIWW--1199dd)) t0o66..8844 ppppbb ((IIWW--11990)f).. PPFFOOAA wwaass NNDD aatt IIWW--1199ce.. IInntthhee aarreeaaooffIIWW-1-144,, nneeaarr tthhee WWWWTTPP,, tthhee hhiigghheerr ccoonncceennttrraattiioonnss ooff PPFFOOAA wweerree ddeetteecctteedd cclloosseerr ttoo sshhoorree aatt IIWW--1144aa ((669999 ppppbb)),, 1IWW--1144bb ((443366 ppppbb)),, IIWW--1144 ((330000 ppppbb)) aanndd IIWW--1144cc ((1122..99 ppppbb)).. PPFFOOSS wwaass nnoott ddeetteecctteeddaat tthhe ootthheerr llooccaattiioonnss aalloonngg tthhee IIW--1144 ttrraannsseecctt bbeeyyoonndd I1WW--1144c ((220000 ffeeeett ffrroomm sshhoorree)).. PPFFOOAA wwaass aallssoo ddeetteecctteedd aatt llooccaattiioonnss eeaasstt aanndd wweesstt oofftthhee IIWW--1144 ttrraannsseecctt aatt lIWW--1155 ((112.22.2 ppppbb)) aanndd IIWW--1133 ((4488..55 ppppbb)).. AAtt tthhee IIWW--99 ttrraannsseecctt,, PPFFOOAA wwaass ddeetteecctteedd aatt lloowweerr ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..00554411 PPb (IW-96) 0.21.5 (IW-94). PFOA was ND at IW-9d and NR at IW-Sc ppb (IW-9f) to 21.5 (IW-ga). PFOA was ND at IW-9d and NR at IW-9e. PPFFOOAA wwaass aallssoo ddeetteecctteedd aatt llooww ccoonncceennttrraattiioonnss nneeaarr tthhee W Weesstt CCoovvee aanndd FFiirree TTrraaiinniinngg AArreeaa aatt llooccaattiioonnss IIWW--11 tthhrroouugghh IIWW--88.. CCoonncceenntrtraattiioonnss iinn tthhiiss aarreeaa rraannggee ffrroomm 00..00332277 ppppbb ((1IWW--55))1to000..112200 ppppbb ((IIWW-3-3),). PPFEBBAA:: PPFFBBAA ,wvaass ddeetteecctteedd iinn tthhee ppoorreewwaatteerr ssaammpplleess ccoolllleecctteedd ffrroomm tthhrreeee ggeenneerraall aarreeaass:: TThhee EEaasstt CCoovvee aarreeaa ((1IWW--2233 ttoo lIWW--2255)):; nneeaarr tthhee DDI1//DD22 aarreeaa ((1IWW--1199)) aanndd nneeaarr tthhee WWWWT~[PP aarreeaa ((IIWW--1144)) aass sshhoowwnn oonn FFiigguurree 44--1155.. CCoonncceenntrtraattiioonnss nneeaarr tthhee EFaasstt CCoovvee rraannggee ffrroomm 115577 ppppbb ((IIWW--2244)) uuppssttrreeaamm ooff tthhee mouth mouth of of tthhee EEaasstt CCoovvee ttoo 113399 ppppbb ((IIW-2-32)3.), aallssoo Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 Report doc om "i4-23 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 33MM_EENNVV_0000000033117711 SM_MNO1483086 3M MN01483096 22116622..00009955 uuppssttrreeaamm. TThhee llooccaatiioonn ddoowwnnssttrreeaamm ooff tthhee EFaasstt CCoovvee ((IIWW--2255)) iinnddiiccaatteeddaa ccoonncceennttrraattiioonn ooff 2233..11 ppppbb.. SSaammpplleess ccoolllleecctteedd ffrroomm tthhee IIWW--1199 ttrraannsseecctt nneeaarr tthhee DDI1/iDD22 aarreeaa iinnddiiccaatteedd PPFFBBAA concentrations ranging from 172 ppb (W-194) 25 fet from shore to 118 ppb (IW-191), c5o0n0cefenettratfioronms rsahnogrei.ngSfarommple1s72coplplbect(IeWd -a1l9oan)g2t5hefeeItWf-r1o9mtsrhanosreecttoc1l1os8erpptbo (sIhWor-e1,9fa)t, d5i0s0tafneceets forfom400shofercet. (SIaWm-1p9le8s) caonldlec3t0e0d faelcotng(ItNh-e19I4W)-1i9nditrcaantesdecltescsleorsecrontocensthroartei,onast distances of 400 feet (IW-19e) and 300 feet (IW-19d), indicated lesser concentrations shore (IW-191) ((00..110088 ppppbb aanndd 11..4400 ppppbb rreessppeeccttiivveellyy)) ooff PPFFBBAA tthhaann tthhee ssaammppllee ccoolllleecctteedd 550000 ffeeeett ftroomm shore (lW- 19f). In the area of I-14, near the WWTP, the higher concentrations of PFA were detected Icnlotsheer atroeashoofreIWat-1I4W,-n1e4aar t(h9e35WpWpbT),P,ItWh-e1h4ibgh(e6r9c5opnpcbe)n,trIatWi-o1n4s o(f28P1FBppAl)waenred dIeWt-e1c4tedde c(7lo3.s1erpptob).shPorFeBaAt IwWas-1d4eate(c9t3e5d aptpob)w,eIrWc-o1n4cben(t6r9at5iopnpsb)(,0.I1W75-104 (02.82152ppppbb))aantdthIW e o-t1h4ecr (T7o3ca.1tiopnpsb)l. oPFnBtAhew1aWs-1d4etetcrtaendseactt lboewyeorndcoInWc-e1ndtrcat(io2n0s0 (f0ee.1t7f8rotom 0sh.o2r8e2),ppPbF)BaAt twhaesoathlseor ldoectaectitoendsaatloloncgatthioensIWca-s1t4atnrdanwseesctt obfeytohnedIIWW-1-144tcra(n2s0e0ctfeaettIfWro-m15s(h8o1r.e1). pPpFbB) Aanwd aIsWa-l1s3o detected at locations east and west of the IW-14 transect at IW-15 (81.1 ppb) and IW-13 ((118533 ppppbb)). AAtt tthhee IIWW--99 ttrraannsseecctt PPFFBBAA wwaass ddeetteecctteedd aatt lloowweerr ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..00889985 (IW-98) 10 5.01 ppb (IW-9). (1W-9e) to 5.01 ppb (IW-9). PPFBBAA wwaass aallssoo ddeetteecctteedd aatt llooww ccoonncceennttrraattiioonnss nneeaarr tthhee W Weesstt CCoovvee aanndd FFiirree TTrraaiinniinngg ara, PFA was ND at IW-1, IW-7, and IW-8 and was NR at IW-2 and IW-4 AArreeaa aatt llooccaattiioonnss IIWW--33 ((00..00997799 ppppbb)),, IIWW--55 ((00..113355 ppppbb)) aanndd IIWW--66 ((00..114466 ppppbb).). IInn tthhiiss area, PFBA was ND at IW-1, IW-7, and IW-8 and was NR at IW-2 and IW-4. 44..55.11..22 SSeeddiimmeenntt SSaammpplliinngg RReessuullttss SSeeddiimmeenntt ssaammpplleess wweerree ccoolllleecctteedd aatt eeaacchh ooff tthhee ppoorreewwaatteerr ssaammpplliinngg llooccaattiioonnss ((FFiigguurree 33--66)). TThhee ssaammpplleess wweerree ccoolllleecctteedd aatt vvaarriioouuss ddeepptthhss aass ddeeffiinneedd iinn tthhee WWoorrkk PPllaann. At mostofthe locarions the sampled intervals were 0- inches and 4-5 inches. A third iAnttemrvoalstwoaf"sthcoellloecctaetidoantsitvhee lsoacmatpileodnsitnotearvmaalsxiwmeurem0d-e4ptinhochfes24anidnch4e-s8. iAnchseusm. mAartyhirodf itnhteersveadliwmeanstcaonlalleycttiecdalatrfeisvueltlsocaraetiopnrsesteontaedmainxiTmaubmle d4e-p10t.h oTfh2e4riensculhtess.ofAtshuemsmedairmyenotf tahnealsyesdesimfeorntPaFnOaSl,ytiPcFalOrAesaunldtsPaFreBAprearseenptreedseinnteTdabinleFi4g-u1r0e.sT4h-e16r1e0su4lt-s15of the sediment analyses for PFOS, PFOA and PFBA are presented in Figures 4-16 to 4-18. Confidential - 3M Insuorm ance Document"si Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc 4-24 Confdential- 3M Insurance Documents 22116622..00009966 33MM_EENNVV_0000000033117722 W3M_MNMONT04184833008977 PPFFOOSS:: PPFFOOSS ccoonncceennttrraattiioonnss wweerree ddeetteecctteedd aatt eeaacchh ssaammpplliinngg llooccaattiioonn ffrroomm aatt lleeaasstt oonnee ddeepptthh iinntteerwvaall aatt ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..223300 ppppbb ((IIWW--44,, 00--44"")) ttoo 11666 ppppbb ((IIWW--2255., 44-88")) aass pprreesseenntteedd oonn FFiigguurree 44--1166.. TThhee aarreeaass wwhheerree PPFFOOSS ccoonncceennttrraattiioonnss iinn sseeddiimmeenntt ssaammpplleess wweerree ddeetteecctteedd ggeenneerraallllyy ccoorrrreellaattee wwiitthh tthhee ddeetteeccttiioonn ooff PPFFOOSS iinn tthhee ppoorreewwaatteerr ssaammpplleess. TThhee hhiigghheesstt sseeddiimmeenntt ccoonncceennttrraattiioonn ddeetteesctteedd wwaass 116666 ppppbb ((IIWW--2255,, 44:-88"")) llooccaatteedd aat tthhee mmoouutthh ooff tthhee EEaasstt CCoovvee.. TThhee ppoorrecwwaatteerr ssaammppllee ccoolllleecctteedd aatt tthiiss llooccaattiioonn ddeetteecctteedd PPFFOOSS aatt aa ccoonncceennttrraattiioonn ooff 220066 ppppbb.. SSeeddiimmeenntt ssaammpplleess ccoolllleecctteedd ffrroomm tthhee ootthheerr llooccaattiioonnss nneeaarr tthhee EFaasstt CCoovvee ddeetteecctteedd PPFFOOSS ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 77..9911 ppppbb ((lIWW--2222,, 44--88"")) ttoo 5599:.44 ppppbb ((IIWW--2233,, 44:-88"")).. AA ddeeeeppeerr ssaammpplleewwasas ccoolllleecctteedd iinn tthhiiss aarreeaa aatt IIWW--2222 ffrroomm 119.95.5 ttoo 2233..55"".. AA PPFFOOSS ccoonncceennttrraattiioonn ooff'2299..11 ppppbb wwaass ddeetteecctteedd. AAtttthhee IIWW--1199 ttrraannsseecctt PPFFOOSS wwaass ddeetteecctteedd aatt IIWW--1199aa aatt ccoonncceennttrraattiioonnss ooff 7799 ppppbb aatt 44--8'"' aanndd 4444:.33 ppppbb aatt 00--44"".. AAtt IIWW--1199bb,, PPFFOOSS xwvaass ddeetteecctteedd aatt 3344..77 ppppbb aatt 44--88"" aanndd 66..8866 ppppbb aatt 00--44"".. LLoowweerr ccoonncceennttrraattiioonnss wweerree ddeetteecctteedd aat ddiissttaanncceess ffaarrtthheerr aawwaayy ffrroomm tthhee sshhoorree.. PPFFOOSS wwaass ddeetteecctteedd iinn IIWW--1199f,, 550000 ffeecett ffrroomm tthhee sshhoorree,, aatt aa ccoonncceennttrraattiioonn ooff 11..4422 ppppbb ((00--44"")) aanndd 00..993377 ppppbb ((44--88"")) SSiimmiillaarr ttrreennddss aarree pprreesseenntt aatt tthhee IIWW--1144 aanndd IIWW--99 ttrraannsseecctt llooccaattiioonnss wwhheerree hhiigghheerr ccoonncceennttrraattiioonnss aarree pprreesseennttnneeaarrtthhee sshhoorree aanndd ddeeccrreeaassee wwiitthh ddiissttaannccee aawwaayy ffrroomm tthhee sshhoorree.. T"Thhee hhiigghheesstt ccoonncceennttrraattiioonn aatt tthhee IIWW--1144 ttrraannsseecctt iiss 7744..55 ppppbb aatt IIWW--1144aa,, 00--44"" wwhhiicchh iiss 2255 ffeeeett ffrroomm tthhee sshhoorree.. AAtt tthhee 1IWW--99 ttrraannsseecctt tthhee hhiigghheesstt ccoonncceennttrraattiioonn wwaassdedteetecctteedd aatt lIWW--99aa ((2277 ppppbb,, 00--44"")) wwhhiicchh iissaallssoo 2255 ffeeeett ffrroomm tthhee sshhoorree.. PPFFOOAA": TThhee aarreeaass wwhheerree PPFFOOAA ccoonncceennttrraattiioonnss iinn sseeddiimmeenntt ssaammpplleess wweerree ddeetteecctteedd ggeenneerraallllyy ccoorrrreellaattee wwiitthh tthhee ddeetteeccttiioonn ooff PPFFOOAA iinn tthhee ppoorreewwaatteerr ssaammpplleess. TThhee hhiigghheesstt ccoonncceennttrraattiioonn ooff PPFFOOAA iinn sseeddiimmeenntt ((FFiigguurree 44--1177)) wwaass ddeetteecctteedd aatt 334411 ppppbb ((lIWW--1144bb,, 44:-88"")).. "TThhee ppoorreewwaatteerr ssaammppllee ffrroomm tthhiiss llooccaattiioonn iinnddiiccaatetdeada PPFFOOAA ccoonncceennttrraattiioonn ooff 443366 ppppbb.. `SSaammpplleess ccoolllleecctteedd ffrroomm tthhee llooccaattiioonnss nneeaarr tthhee EEaasstt CCoovvee ddeetteecctteedd PPFFOOAA ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 33..11 ppppbb ((IIWW--2233,, 44--88")) ttoo 113300 ppppbb ((IIJVW-V2-255,, 44--88")"). Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 Report doc om "32s 4-25 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 33MM_EENNVV_0000000033117733 I3MM_MMNNO011448833009988 22116622..00009977 Ae 1-19 amc he highs consmrmion of PFOA was dtc a W-A9bcd At the IW-19 transect the highest concentration of PFOA was detected at IW-19f located 550000 ffeeeett ffrroomm sshhoorree aatt aa ccoonncceennttrraattiioonnooff 4422..77 ppppbb aatt 44--88"". Ath IWe14 and 99 ast otonsigherconcnrons as presen cr the shore At the lW-14 and 1W-9 transect locations higher concentrations are present near the shore an dese with dance vy rom he shore. Th highest onsen atthe W186 and decrease with distance away from the shore. The highest concentration at the IW-14 ect 341 pp TW-14, 4:5 which i 5 st from he shore. At the We rnc transect is 341 ppb l~V-14b, 4-8" which is 50 feet from the shore. At the IW-9 transect the het concntton was dette t I-93 12 pi, +) which is 25 ft fon the the highest concentration was detected at IW-9a (12 ppb, 4-8") which is 25 feet from the orsshore. PEA. The areas wher PFA concenaons in semen samples wee deed also PFBA: The areas where PFBA concentrations in sediment samples were detected also ener comtte ith he detstonof PBA i the pester supe. generally correlate with the detection of PFBA in the porewater samples. The igh concnraton of PFBA in sediment was dtd a comcnion of 264 The highest concentration of PFBA in sediment was detected at a concentration of 264 PRB cononationcf 695 pb ppppbb ((IIWW--1144bb,, 44--88"")) ((FFiigguurree 44--1188)).. TThhee ppoorreewwaatteerr ssaammppllee ffrroomm tthhiiss llooccaattiioonn iinnddiiccaatteedd aa PFBA concentration of 695 ppb. Samples cll fom th oan nes he Et Cove detected PEBA concntrons Samples collected from the locations near the East Cove detected PFBA concentrations raging rom 0345 po (W-20, 160) 1055. py (IN-25, 4). The concentration ranging from 0.345 ppb (IW-24, 16-20") to 53.4 ppb (IW-23, 4-8"). The concentration at IIV-25 at he mouth fe cove 353 pl (45) Pewter sample esl om IW.23, IW-25 at the mouth of the cove is 35.3 ppb (4-8"). Porewater sample results from IW-23, IIWW--2244 aanndd IIWW--2255 iinnddiiccaatteedd PPFFBBAA ccoonncceennttrraattiioonnss ooff 113399,, 115577 aanndd 2233..11 ppppbb rreessppeeccttiivveellyy.. AAtt tthhee IIWW--1199 ttrraannsseecctt tthhee hhiigghheesstt ccoonncceennttrraattiioonnooff PPFFBBAA wwaass ddeetteecctteedd aatt IIWW--1199aa llooccaatteedd 2 fect fom shor at comcenton of 108 pp a +5" PBA was dete nthe 0 25 feet from shore at a concentration of 104 ppb at 4-8". PFBA was detected in the 0-4" {ample st concenaion of409 pp. Concenaons of PFBA decreas from is pin sample at concentration of 40.9 ppb. Concentrations of PFBA decrease from this point avy fom shore unl the 50 sl locaton 1W-19) hor the scond highest away from shore until the 500 ft sample location (IW-19f) where the second highest PFDA concentration ws deed in th 4" sample at 3 concenaion of 70.1 ppb PFBA concentration was detected in the 4-8" sample at a concentration of 70.1 ppb. PFDA was detected in he 0-4 sample ot a concentration of 204 pob. The porwr PFBA was detected in the 0-4" sample at a concentration of 20.4 ppb. The porewater ample ets sso xlibit 2 similar trend where PFDA concentons dcr at sample results also exhibit a similar trend where PFBA concentrations decrease at concentration of 13s ddiissttaanncceess aawwaayy ffrroomm sshhoorree uupp ttoo tthhee 550000 ffttssaammppllee ((IIWW--1199ff)) wwhheerree PPFFOOAA wwaass ddeetteecctteedd aatt a concentration of 118 ppb. ACh I-18 nce the ighest BA concenation (26 pb, 48) ws dette at At the 1W-14 transect the highest PFBA concentration (264 ppb, 4-8") was detected at ITWW--1144bb,, llooccaatteedd 5500 ffeeeett ffrroomm sshhoorree.. AAtt tthhee IIWW--1144cc llooccaattiioonn ((220000 fftt ffrroomm sshhoorree)) concentrations of 64.5 and 87.8 ppb were detected at the 0-4" and 4-8" sample intervals concentrations of 64.5 and 87.8 ppb were detected at the 0-4" and 4-8" sample intervals Ee Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 Report doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss4-26 33MM_EENNVV_0000000033117744 swnnn 3M MN01483099 22116622..00009988 rreessppeeccttiivveelyly.. HHoowweevveerr,, ffrroomm IIWW--1144dd ((330000 fftt ffrroomm sshhoorree)) ttoo lIWW--1144ff ((550000 fil ffrroomm sshhoorree)) PPFFBBAA wwaass nnoott ddeetteecctteedd.. TThhiss trreenndd iinn PPFFBDAA ddeetteeccttiioonn iinn sseeddiimmeenntt iiss ccoonnssiisstteenntt wwiitthh tthhee ppoorreewwaatteerr ssaammppllee rreessuullttss aalloonngg tthhee IIWW--1144 ttrraannsseecctt wwhheerree PPFFBBAA ccoonncceennttrraattiioonnss ddeeccrreeaassee aatt tthhee 330000fftt ((IIWW--1144dd)) ttoo 550000fftt ((IIWW--1144fI)) ssaammpplliinngg llooccaattiioonnss.. AAtt tthhee IIWW--99 ttrraannsseecctt llooccaattiioonnss PPFFBBAA ccoonncceennttrraattiioonnss iinn sseeddiimmeenntt rraannggeedd ffrroomm 44..1155 ppppbb. ((1IWW--99,, 44-78)")1t0o 22.1166ppppbb ((IIWW--99bb,, 1144--1188"")).. FFrroomm IIWW--9gdd 1to0 IIW-9-97f PPFFBBAA wsaass nnoott ddeetteeccetedd.. LLiikkeewwiissee,, tthheerres ~wveerree nnoo PPFFBAA ddeetteeccttiioonnss iinn sseeddiimmeenntt ssaammpplleess ccoolllleecctteedd ffrroomm llooccaattiioonnss uuppssttrreeaamm ((wweesst)) oofftthhee IIWW-.9 ttrraannsseecct.t. TThheessee rreessuullttss aarree aallssoo ccoonnssiisstteenntt wwiitthh tthhee ppoorreewwaatteerr ssaammppllee rreessuultss wwhheerree PPFFBBAA wwaass ddeetteecctteedd aatt llooww- ccoonncceennttrraattiioonnss nneeaarr sshhoorre aatt tthhee IIWW--99 Detected" o detected at concentrations les than 0.510 ppb aarreeaa.. AAtt ddiissttaanncceess aawwaayy ffrroomm sshhoorree aanndd uuppssttrreeaamm,, PPFFBBAA iinn ppoorreewwaatteerr wwaass eeiitthheerr ""NNoott Detected" or detected at concentrations less than 0.510 ppb. 44.551. 1..33 SSuurrtfaaccee WWaatteerr SSaammpplliinngg RReessuuilttss Surface wate samples were collected at each of the porewater sampling locations. At cSaucrhfalcoecawtaotne,r asadmispcrleestewwearteercoslalmepctleedwaatsecaoclhleocft"etdheuspinogreawpaetreirstsaaltmicplpinugmploactat2io0n%s.anAdt e8a0c%h loofctahtieond,epatdhisocfretthee wwaatteerr.saBmotphleswamapslceosllweecrteed aunsailnygzeadpaesrisdtiaslctircetpeusmapmpalte2s0f%oraFnCd a8n0a%lysoisf,tahe ddeefpithnedofitnhtehewWatoerr.kBPolatnh. saAmspulemsmwareyreoafntahleyzaendalyatsicdailscrreestueltssamar plepsrefsoerntFeCd ainnaTlaybslise, 4a1s1d.efTinheed rinesthues WofotrhkePalnaanl.yAsessufmormPaFryOSo,f tPhFeOaAnaalyntdicaPlFrBeAsulatrsearperepsreensteendteidn FiinguTraebsle441-9111.0T4h2e1results of the analyses for PFOS, PFOA and PFBA are presented in Figures 4-19 to 4-21. GGseaenmneperlraeallllyyloclloaotwwionFFsCC. Near the Exst Cove at location IW-23, PFBA was ccoonncceennttrraattiioonnss wweerree ddeetteecctteedd iinn ssuurrffaaccee wwaatteerr ssaammpplleess aatt 33d44etooeffcttthehdee at4433. csaomncpelnetraloticoantisonosf. 6N92eaprpbthe(1.7 )East aCnodv6e.7a6t plpobca(t6io.n7).IWP-2F3B,APwFaBsAalswoasdetdeectteecdteadt 1a7t cootnhcrenTtorcaattioionnssowfit6h.92hipgphebr(c1o.7ncfetn)traantdio6n.s76repppobrt(e6d.7atft)I.WP-F09BA(1.w2a4s paplbs,o 2de8te,ctedIWat-1117 other locations with higher concentrations reported at IW-09 (1.24 ppb, 2.8 ft), IW-11 091kand 1.96 ppb3.6,10), ((22..5588 ppppbb., 33..44 ft aanndd 11.3 .3 ppppbb,, 1133..44 fftt)),, lI~WV--1199a ((44..2288 ppppbb., 44..44 ff1t)) aanndd 1IWW--1199bb ((22.8811 ppppbb., 0.9 ft and 1.96 ppb, 3.6 ft). PROS was detected at 19 locations ranging from 0.0539 ppb (I-15, 38 110.0539 ppb (we22,49) PFOS was detected at 19 locations ranging from 0.0539 ppb (IW-13, 3.8 ft) to 0.539 ppb (IW-22, 4.9 ft). Confidential - 3M Insurance D--ocumenti s Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 Report doc 4-27 Confdential- 3M Insurance Documents 22116622..00009999 3MM_ENEVN_V0000000301371575. W_MNOT483100 3M MN01483100 PFOA was detected at 30 of" the 43 locations at concentrations ranging from 0.0518 ppb (1TWw--003y, 44..5 ft))ttoo 0..6611 ppb ((IIWW--2222,, 1.2 ftt)).. 4.5.2 Transect Locations 4..55..22. 11 SSeeddiimmeenntt SSaammpplliing RReessuulltts Sediment samples were collected at three transect locations across the Mississippi River. One transect upstream of the Cottage Grove Site (XS-01) and two downstream; XS-02 ((aabboovvee tthhee HHaassttiinnggss ddaamm)) aanndd XXSS--0033 ((bbeellooww tthhee HHaassttiinnggss ddaamm).). TThhee ssaammpplleess wweerree collected from the top of the sediment layer using a petite ponar grab sampler as defined in the Work Plan. The sediment sampling results for PFOS, PFOA and PFBA are presented in Figure 4-22. A summary of the analytical results are presented in Table 4-12. PFOS was the only FC compound detected in sediment salnples along the three transects. Concentrations of PFOS were detected at each of the 13 sample locations at akz2 SureSammpo tsru concentrations ranging from 0.289 ppb (XS-01c) to 2.66 ppb (XS-02a). 4.5.2.2 Surface Water Sampling Results Surface water samples were also collected at the three transect locations across the Mississippi River. The samples were collected at 20% and 80% of the water depth at each transect. At the middle transect (XS-02) an additional sample was collected from the water surface at each of the five locations, as defined in the Work Plan. A summary of tthhee aannaallyyttiiccaall rreessuullttss aarree pprreesseenntteedd iinn TTaabbllee 44--1133.. TThhee rreessuullttss ooff tthhee aannaallyysseess ffoorr PPFFOOSS,, PFOA and PFBA are presented in Figure 4-23. OOnnllyy PPFFOOAA wwaass ddeetteecctteedd iinn 33 ooff tthhee 3300 ssuurrffaaccee wwaatteerr ssaammpplleess ccoolllleecctteedd.. TThhee concentrations were 0.0501 ppb (XS-03b, 4 ft), 0.0523 ppb (XS-03c, 14 ft), and 0.199 ppppbb ((XXSS--0022e,, 00..00 fftt)).. PPFFOOSS aanndd PPFFHHSS wweerree nnoott ddeetteecctteedd iinn aannyy ooff tthhee ssaammppleless.. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttiss28 4-28 22116622..00110000 33MM_EENNVV_0000000033117766 3M MN01483101 4.5.3 Longitudinal Locations 44.. 55.33.. 11 SSeeddiimmeenntt SSaammpplliinngg RReessuullttss Sediment samples were collected at seventeen locations along the Mississippi River at locations upstream and downstream to the headwaters of Lake Pepin. At each location the samples were collected fom the top of the sediment layer using either a petite ponar grab sampler or clear polycarbonate tubing. At the headwaters of Lake Pepin sediment cores wweerree oobbttaaiinneedd aatt ffbouurr llooccaattiioonnss ((LLSS--778844 aa,, bb && c aanndd LLSS--778855)) ttoo aa mmaaxxiimmuumm sseeddiimmeenntt depth of approximately 3 feet. Three discrete samples were collected and analyzed for FFCCss ffrroomm eeaacchh ooff tthhee ffoouurr llooccaattiioonnss.. AA ssuummmmaarryy ooff tthhee sseeddiimmeenntt aannaallyyttiiccaall rreessuullttss aarree presented in Table 4-12. The results of the analyses for PFOS, PFOA and PFBA are presented in Figure 4-24. PPFFOOSS aanndd PPFFOOAA wweerree tthhee oonnllyy FFCCss ddeetteecctteedd iinn tthhee sseeddiimmeentn.t. OOtthheerr FFCC aannaallyytteess wweerree either ND or NR at each of the longitudinal sampling locations. PFOS was detected at 12 ofoftthhee 1177 llooccaattiioonnss.. PPFFOOSS ccoonncceennttrraattiioonnss aatt tthhee hheeaadd ooff LLaakkee PPeeppiinn ((llooccaattiioonn 778844)) rraannggee from 1.22 ppb (LS-784a, 0-0.65 ft) to 3.16 ppb (LS-784c, 1-2 fl). PFOS was not detected in the sediment samples collected from location LS-785 which is the next closest upstream sample location. PFOS was also not detected at locations 791,797 (duplicate), 803, 815 and 821. The other locations where PFOS was detected range in concentration fom 0.983 ppb (LS-809) to 0.142 ppb (LS-806). PFOA was detected only at location LS-784 a, b and c at the headwaters of Lake Pepin. Detected concentrations from these samples range from 1.09 ppb (LS-784b~ 2-2.5 ft) to 00..444411 ppppbb ((LLSS--778844aa,, 00.6655--11.33 f1t)),. 4..55.33..2 SSuurrffaace WWaatteerr SSaammpplliing RReessuulltts SSuurrffaaccee wwaatteerr ssaammpplleess wweerree ccoolllleecctteedd aatt tthhee sseevveenntteeeenn llooccaattiioonnss aalloonngg tthhee MMisisssiissssiippppii River at locations upstream and downstream to the headwaters of Lake Pepin. _At each llooccaattiioonn tthhee ssaammpplleess wweerree ccoolllleecctteedd ffrroomm 2200%% aanndd 8800%% ooff tthhee ttoottaall wwaatteerr ddeepptthh aanndd combined as a single composite sample from each location for FC analyses. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt1ss29 4-29 33MM_EENNVV_0000000033117777 3M MN01483102 22116622..00110011 AA ssuummmmaarryy ooff tthhee aannaallyyttiiccaall rreessuultss aalloonngg wwiitthh tthhee ddeepptthhss ooff tthhee iinnddiivviidduuaall ssaammpplleess aarree pprreesseenntteedd iinn TTaabbllee 44--1133.. TThhee rreessuullttss ooff tthhee aannaallyysseess ffoorr PPFFOOSS,, PPFFOOAA aanndd PPFFBDAA aarrec pprreesseenntteedd iinn FFiigguurree 44--2255. PPFEBBAA,, PPFFOOAA aanndd PPFFBBSS wweerree tthhee oonnllyy FFCCss ddeetteecctteedd iinn tthhee lloonnggiittuuddiinnaall ssuurrffaaccee wwaatteerr ssaammppleless.. PPFBBAA wwaass ddeetteecctteedd aatt 77 ooff tthhee 1177 ssaammppllee llooccaattiioonnss rraannggiinngg ffrroomm 00..00770055 ppppbb ((LLSS--881155)) tto0 00..00553300 ppppbb ((LLSS--778844cc).). AAtt tthhee rreemmaaiinniinngg llooccaattiioonnss PPFFBBAA wwaass eeiitthheerr NNDD oorr NNRR. PPFFOOAA wwaass ddeetteecctteedd aatt 33 llooccaattiioonnss rraannggiinngg iinn ccoonncceennttrraattiioonnss ffrroomm 00.00775511 ppppbb ((LLSS--778855)) ttoo 00..00550088 ppppbl ((L15S--880066).). AAtt tthhee rreemmaaiinniinngg 1133 llooccaattiioonnss PPFFOOAA wwaass eeiitthheerr NNDD oorr NNRR. PPFEBBSS wwaass teihtheerr NNDD oorr NNRR.. T"Thhee PPhhaassee 1| aanndd PPhhaassee 22 aasssseessssmmeenntt rreessuullttss aass pprreesseenntteedd iinn tthhiiss sseecctioonn aarree ssuummmmaarriizzeedd iinn SSeeccttiioonn 55----SSuummmmaarryy ooff OObbsseerrvvaatitioonnss,. Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc om "330 4-30 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 22116622..00110022 33MM_EENNVV_0000000033117788 SM_MNO14E3103 3M MN01483103 aTY v > AN i a Pe rekisey a _ Sol i ses A -- bo I Laae s a yy o rwm CE = = wn X ib Xal | :i | [loSe il, ) Nk bh. p NEN E| D aE Nea) NC RINNEu N aaC n N ermal wi el | -- IR BER ve. 7 we iCRcooNrt E ME L W am E a3g Ld ack Nl O I B L; o 1 ed] :WR AN AEP E NR bt NaeNR BenRco | if S Me E e ESSOS OEE a ~~ EN "18 mm foAR TT Legend: 3 A Re WEE| 0 l~ re - 686.47 } N Ground,aater Elevation Contour (ft MSL) Monitoring Well Production Well 500 1,000 2,000 Feet Groundwater Elevation (ft MSL) Groundwater Flowline Map Source. U S Deparlmenl o~ Agriculture, F~rr~ Services Agency, Eis BOAR D~jitat Orthorect~fled Images (DO,j, Minnesota, 20G3 ew FIGURE 4-1 GROUNDWATER ELEVATION CONTOUR MAP PUMPING CONDITIONS fr3 MAY 2006 COTTAGE GROVE SITE So 3M ENV 00003179 3M MN01483104 22116622..00110033 BE Eas 7 " EA NY J Eo L 3|d] i = ZC tel ls |4 lid Ellie Be BE 7 HE pd j Silo 2=fg =HEIF 0 g J =n Bl || 2 3 " a 7 = A | Han i=l <2 1 < =$ <2 5cg2% F."A 3 3J : < a H [E | Pl, <i hi: vo BCs 5, qr Pal pau aA /No = po2 oakst52f] d[=e a : le Are EEE & Ee HSE Ship BL: (82 Is 52 55 Barmy Fo . o j E pie i . e t4]a= n 2 S2!| i EE / 4c |=1e = [i F RR = . 22116622..00110044 !] 2 [Ei ; 5 ll || s2[8] q A =~. lL 33MM_MMNN0011448833110055 ! RTE al : Ts 3.0a08s [Eth PE<7R & i | FepiEsR.E.. $2BEEIEEY`Nd i EZnnioeriyl . I gq 5 Cergeay gN2FiTizTiTiEy G53alcadl :Z sa a 2 : wh WIE E4o } 7 a TIv Ps p A a vA i a. 8 is "dq i WH 5 oIeo teg af pfle SEY JWaagiresa dS }; 5<27 el pdm|ae=cd3 Ji} elFleeHene0d0sf inTERE LToy T *TE A LElaicreniy BE oN 4J Cf PEE dacealu STN 4 , # LEeLmTan | p9a.n..e.l0s. sieJ Eta | 2 Ul -- i C] RAB ITaiaa)[< [13ncpu3 ranec3e03]Of 5 22116622..00110055 !] i esznsd 29 I: Hles p| eessal5% | | i H "oR 8 Els B oso3EzEEaE iElE = S|53 6 2 REY J . 0Y =. i< Ed os 1 feiieg 1 Elzzyiss 15FErRaG ii i; i : SUN 483105 3M MN01483106 Be, or Yb RE a qr na ail FE, TH Ee lec ET H el r i r3e]n Imi I 3 1 ET Gs) ER Wopy e DEM e 23 SB D5B03 By BEE] Average PFOS (ppb, ngfg) 12.7 116 140 eg E ela rCele SB DSB01 Sample Depth Average PFOA Average PFOS ae1522] oii =| 2133 37.3 33.3 RVG (bgs) (ppb, ng/g) (ppb, ng/g) 0 - 0.5 feet 0.5 - 5 feet 5 - 10 feet Ton| 10 - 15 feet 3 15 - 20 feet 20 - 25 Refeet cgeae k|ewds 2.57 62.8 53.6 (41.5) 68.9 146 16.1 112 336 (298) 143 43.6 29.2 B 9.94 co Lo RRTenTe SB-D5B05 Sample Depth[ Average PFOA] Average PFOS [bgs) ~ (ppb, ng/g) I [ppb, ng/g) g RU Ua h Fs O- 0.5 feet 0.5-Sfeet I I %; i ~ 5-10feet | o.587 ri T*ie II 59.2 31 5 | 9.~ 269 5 a Lg 8 iE SB-D5B02 ST Sample Depth (bgs) 0 - 0.5 feet 0.5 - 5 feet Average PFOA 5.72 29.2 Average PFOS 58.3 1640 See Sample Depth (bgs) 0 0.5 feet 0.5 - 5 feet 5 - 10 feet 10 - 15 feet SB-D5B06 Average PFOA (ppb, rig/g) 15.5 33.2 33.7 33.4 Average PFOS (ppb, ng/g) 395 293 66.6 247 15 - 20 feet 106 128 Gf 20 - 25 feet 13.3 20.7 5 - 10 feet 86.5 2650 cael 10 - 15 feet 15 - 20 feet 20 - 25 feet mon 62.3 166 20O 322 26.1 3.15 Pin. SB-D5B04 Sample Depth Average PFOA Average PFOS (bgs) (ppb, ng/g) (ppb, ng/g) 0 - 0.5 feet 3.13 32.3 0.5 - 5 feet 2.61 301 5 - 10 feet 8.06 147 10 - 15 feet 21.3 52.6 15 - 20 feet 16.7 (17.0) 85.0 (89.0) 20 - 25 feet 25.7 38.7 [ro M---- Legend: @ Soil Borhlg Location $5 EY bgs Below ground surface 0 150 300 mFeet Confcists Note: Concentrations Conf in Insuran parentheses are I nsu ran EOE Map Source. U a Depat~n~ent of Agr[cultlire, Farm ae Setv~es Agency, on Minnesofa, 2003 | oes FIGURE 4-4 D5 AREA SOIL BORINGS PFOA AND PFOS CONCENTRATIONS amERGJoUNfEb20s061Es 3M 33MM_MMNNO011448833110077 22116622..00110066 Be ae en | SB-DgB04 Average PFOS (ppb, ng/g) vmll m 2 |=&663 391 FERRE3390 9960 4210 4 | ho Eo Ta wage fly 3 o- e SeS 1060 | E20 Fi oi 1] |Pyeae rCmaA~R dg Sample Depth ME EA PE (lags) 0 - 0.5 feet ira] as | Je 0.5 - 5 feet SB-D9B01 Average PFOA (ppb, ng/g) 25.3 2860 Average PFOS (ppb, ng/g) 54.9 1560 poe] 5 - 10 feet 10 - 15 feet 15 - 20 feet Em | 3210 (3080) 8890 10700 154 (178) 29500 27800 20 - 25 feet 955 1950 Sample Deptb (bgs) 0 - 0.5 feet 0.5 - 5 feet = 5 - 10 feet 10 - 15 feet 15 - 20 feet 20 - 25 feet SB-D9B03 Average PFOA (ppb, nglg) 3.40 41.4 45.9 0.283 1.37 (0.895) 0.0620 Average PFOS (ppb, ng/g) 131 145 6.54 1.01 9.05 (6.30) 2.26 mada Sample Depth (bgs) 0 - 0.5 feet 0.5 5 feet 5 - 10 feet 10 - 15 feet 15 - 20 feet 20 - 25 feet SB-D9B02 Average PFOA (ppb, ng/g) 15.9 4.68 25.6 38.9 8.55 19.9 Average PFOS (ppb, ng/g) 70.1 123 78.0 60.8 15.4 39.7 TR 3 l,egend: ? @ Soil Boring Location bus Ho god aie a. bgs Below ground surface os 1 Co pate | eo Notes; 1. Concentzations in parentheses are rae ae hen field duplicate results. ConfEiYecleneaalewoMSSNatan EOSEE 2 on 2. Since these samples xvere collected 0 150 300 =Feet Map Source: U S Department of Agricuffute, Farm Se~v~es A#ency, 4 FCs. Minneso~, 2003 Fe: ,\Fr,~s,cG\prqTdSo~sgc_Glmv<\n xdsSDgarca~sb~PFBS_PFHS_PFOS_PFOA mxd 28-dun.07 14:33 rcksc 22116622..00110077 PFOA DA099NDAARRPEEFFFAAOIIGSGSSUUOOCRRIIOEELLN4B1DC:-OOE55RRNITINNRGGASSTIONS COT YTOORNES0ROVTEE PFOA AND PFOS CONCENTRATIONS JUNE 2006 mE 0de31e3 COTTAGE GROVE SITE 3M ENV 00003183 SM_NO14E3108 3M MN01483108 pH J oN i co \ o Ete e ee OF = Bie% i LwS o RY Fo. Naar pl il pk WR Ee ea Ry ale . my rE x BN Ean Wy em em-- FonLoaLi [a | i [1k SEL 0; eiys EAa N Eo ] o A C o i Ro =H & wr fo) ge :ER ip - SheLsah ig 5 [ IE CoT | eona |e eure |"een| os a i 4 as aahEy dod MISSISiFhISbViEIiRFcPdLiPOtIeW St Sn 0.00 Legend: @ Soil Boring Location Not detected at or above die ND acceptable Limit of Quantitation (LOQ) NNRR NNeott rreeppoorrtteedd dduueettoo qquuaalliittyy, ccoonnttrrooll failures. failures. [Sp ---- '--ugs Below grouua" surface Conicloolnitniadiinsurance field duplicate remits JoraoESE ---- 0 150 300 ~Feet ee~ap s.... U.S Depatfme~t of A r u~ure Farm Sendces Agency, DIRSRE SIH... e, Na#onalAgricu#ural Petes ~.....,~. ~o~ b O P O~ P Arnxd 28-Jur~07 4:75 nouns FIGURE 4-6 RE TRANG AREA SOIL FIRE TRAINING AREA SOIL PPFFBBAA., PPFFOOAA AANNDD PPFFOOSS CCOONNCCEENNTTRRAATTIIOONNSS SEPTEM0BkER SEPTEMBER 2006 COTTAGE GROVE SITE | WERESB605 EE" | 3M ENV 00003184 Su_ores10s 3M MN01483109 22116622..00110088 [ en mai w || Nasa aS ER NR, L13583 vy. py a EN EN BR i WL dEe tPa l RL oBORNC NFe TNi! a Lms \ Ae arSd Li VFvim 7 87 2sesTSwO o BF42 B2)Y V5 THA FE 2 3 5 a RA ATT i U oH A E WeE / | aa a be oe BE id . EACAkAlT 877E Ti Tb e ia WS ~<Y - = ry i iHy i nil ey G rrameo raeis ff | {Hh | alaln,lRS RE endl a ASfwLl L. ] 7Fy |Ganriental- Sm nstra@Boldmehts 22116622..00110099 ii E ib i i El EgElEi owen sdgostes 000 3M ENV -- 3M MN01483110 = mi hea b hy. ) yaks ; 5 ! BN ra pT Wy 5 ' 4 A he .2 7 be & en)5 La N 2 fi 4 2 E Mg M 4 A h Ta oy, gy in s ; BRay. Rsv vseerra||rs0nros]| Troerea J1 oon IEE IE EE RON n Fy Tr a ay LeS gend S NES f T Legend: 2 meee + EE East Cove J S, z ~ Pha~c 2 Smfacc Water Salnpling Location O 75 150 , Feet AR trenddeci fie EEE een onfidentialm3M Insurance NR Not reported due to quality control failure. ~ ~~-~aL~:~SM Insurance PoSURRBHES momen, File: \~Fs,~6\proj6\Ce,~age_Grove\mds\surD, ce\~tater_eastcose rnxd, 28 Jun-07 14: 42, ricksc *4 oy SET Ls Hous sx Pea, PFBA, PPFOASSF UASESRUNRAFDFFAIASO PGACTFUCOERECSEWWOCA CA4VAAO-TET8TNEAECRRENTRTRATAITOIONNS,S COTSSTEEAPFEGTATEEESMMTGBBCREEOORRVV2E0E0S0I6TE 33MCMO_TEETNNAVGV_E00G00R00O00V33E11S88I66TE 3SMM_MMNN0O1T4a83E1311111 22116622..00111100 AY he hi he. . \ i A h N pp Y o i: Sample Depth EC06 Average PFBA Average PFOA (ppb~ ngig) [ppb, ng/g) Avorago PFOS (ppb, ng/g) ---- Sample Depth 0 - 8 inches Be 20 - ~6 inches EC05 Averag~ PFBA Average PFOA (ppb, rig/g) (gpb, rig/g) 18.2 996 (694) Average PFOS (ppb~ rig/g) NR 65450 (NR) 6 inches 42incqes 71 J|incqes 16.9 40.0 440 58850 bh . gs3.11 NR 37 - 43 inches 1845 NR \NN \ Sample Depth a -- 0 - 6 inches Ol 14 - 20 inches 4 Ey 47 53 inches EC07 Avelage PFBA (ppb, ng/g) Average PFOA (ppb, ng/g) 7.90 31.2 0.764 Average PFOS (ppb, ng/g) 1145 1985 NR [on or [re Torr Pee aL - Sample Depth 0 - 6 inches EE [2] erE ) an! 30 - 36 inshes EC08 Average PFBA Average PFOA 19.2 NR 24.1 122 Average PFOS (ppb ng/g) NR 3590 59 - 65 inches 30 8 335 NR [yos e[o4 a r~~TeDNnR i !R~eA | eeH\ E d\ LE iE =~ ]E Ta R RTEEw --E --a-- Sample Depth 0 - 6 inches iy 8 - 14 inches ECD01 Average PkBA Average PkOA (ppb, ng/g) (ppb, ng/g) 26.5 11.3 Average PFOS (ppb, ng/g) NR 63.8 Sample Depth 0 - 6 inches 14 - 20 inches 34 - 40 inches EC10 Average PFBA (pph ng/g) Average PFOA (ppb ng/g) 200 946 140 88.6 29O 121 Average PFOS (pph, ng/g) 118 2965 2850 Sample Depth EC09 Avelage PFBA (ppb, ng/g) Average PFOA (ppb, ng/g) Avelage PFO5 (ppb ng;g) 0 - 6 inches 51 6 164 20 26 inches NR NR 36 42 inches 113 9150 I nT "i rh rn EE En ET EJ bmcme Legend: D East Cove 9 ER ~ Phase 2 Sediment Sampling Location Confidetiakz insurance NR ~-ot reported due to quality control failure. ND Nokdtd ohLine of Quanitaion " 1.00) ND Not detected at the Limit of Quo~atitation (LOQ) 0 75 150 ~Feet er UXEatsat rem nse MapSoume: DoSEBHEE- U.S. Department ofAgrieu#ure, Farm Services Agencx Fie: dF,~wc6\proj6\Cottage_Grovd, rnxds\sedirne~Leastcove~T~d, 2%Jura07 14:45 EET Hoye FIGURE 4-9 SEDIMENT PFBA, PFOA AND PFOS CONCENTRATIONS SEN Jones? (CO`STESTEPEAPTGATEESEMTMGBBCREEOORRVV2EE200006S6.ITE COTTAGE GROVE SITE 3M ENV 00003q87 morass 3M MN01483112 22116622..00111111 WOE NEeE R NN CR ECE, USNR SNES ARRRWNNEHwR i AAR TR (N Le E WPa EsEEJANeE g ke Sha RN (LS Sd SX pS i eSaS es R A RE S OI RLNS N Eh RO "XgE eDnHYATemCNNegnNNNtSHArsEsge 3 LIARSNNO NTE (aie) EOS Aa (Be 7 CehGaRl ILDRCSTSNS NR 77S JaS E nEl L ei ali And s hl" Sa CS leAR i HlNn e(& NE i Re) ERNE a al SE laesa sd , o LAx R ) QD uD eE llNeEYie Pra br 1 ne ag teh IN T e a e mm 3 eae er sae West Cove AeEE nm eT ee =Legend: 3 seers . ~ SurfaceW~er Botmdary indice tila CCoonfnifddeenntitiaall -- 33MM IInnssuurraanngsee DDooccuummeennttss 22116622..00111122 na FIGURE 4-10 Ow WEST COVE TOPOGRAPHY AND SURFACE WATER BOUNDARY COTTAGE GROVE SITE 33MM_EENNVV_0000000033118888 suorassi1s 3M MN01483113 wee ne3s = a 348 5 II how) pbgm) | (ppb. Igin) | pb gmt) i :Hk pr Nx % | - hy 1] \ Bs oe p: Ee| - ss tt Pe pe ad = =fer v 3% N of | = 14 = 1 ; : a i Legend: 3 W woetstcCoonvee ~ ?ha~e 2 Surface Water Sampling Location Se 0 EE = 75 150 I Fe et Ganfidential. aM NR Not reported due to quality Insurance con;rol failure. DocEHRHE 2rrres, Map Source. U.S. Depar~;en~ crf Agricultur~ Farm ServicesA#ency, File: '~,FswcS\proi6\Co~age Gio'e\mxds\surfacev~a er *~,estco,~e rnxd, 28-Jut-07 14:46, ricksc FFIIGGUURERE4-41-111 SURFACE WATER PFBA, PFOA AND PFOS CONCENTRATIONS WEST COVE EEA SEPTEMBER 2006 3M MN01483114 22116622..00111133 wo y Taw vo = ASYl: er BD i, J E i -: : fh --- ta Re Eh\he di, Ny weae ih k= \ 5 1% =. } ; gu ; feds deliil Re 5 ' 35 ees RL er pr 1 worcme Legend: West Cove A ?hase 2 Sediment Sampling Location <r 0 URE 75 150 ~ Feet ConfrintteshEInsurance [DoCg HERRIy ESmmse,s N R Not reported due to quality control failure. D ~ O/ Program Fie: ~\Fsv,.86~proi6~Doftage Grave\mxds\sedimeqt westcove md 28-Jun-37 iz50, rickc rouRE 412 FIGURE 4-12 SEDIMENT PFBA, PFOA AND PFOS CONCENTRATIONS COTTAGE GROVE SITE WEST COVE SEPTEMBER 2006 33MCMO_TEETNNAVGV_E00G00R00O00V33E11S99I0T0E 3M MN01483115 22116622..00111144 ig raw| &r. - : 7a E83 > Je 0 Tn SSPE iy i Lan Hla Tig (Ld 88 ge ii a oy . Is = |-- i 2162.0115 3M MN01483116 "aE 2 SerWw ay A : Lag Vem uh files nl nL } !t =de pid s J Bis |p& ST EE = 2162.0116 3M MN01483117 a oe SEE : SAN =] 1 vam LL `a 4 ; :a Le ol "i eo 4 eea, = Wl ang ST Aiy 8 EA & : Lo : :In4s " ik Aen Ta 4 7 :! 2162.0117 : nN 3M MN01483118 : of i(i : )& AsyLgl -- rE GREE :- : J 0 ra SR a Zl vi iE ; y : BEE Ta Ey 2] i El; Le Le io.AoH # le 2s 88 ee GME LE TE dl di i | PLEA | in ra - LE dl lo AXE Ffead WE: DRRNE SONEN ie : 3M MN01483119 2162.0118 b Li 2a @; LAE Ha i !EES ; a =a Ne ca. i | A HE Fila 4 i N n ; ao 3M MN01483120 2162.0119 : hd AHh giel2: I Ma EE AEE un ) fol EA RE Jy SRE .- rary/ : | fond IB iE GLE 2162.0120 3M MN01483121 Wf Eee py REC fr | b4d CFEE FAS | i= Ala Bae a i mma] | Te | mECdE i 3 I| N B- : mLE od fe; a B Ha 5 i | (ge ; faz alEoln I. NEE 3M MN01483122 2162.0121 E28 7 f tL 4 Hiatuit i is (| 5 T E EE| a a a Fd RAGE y 8 al B HTa ee k . a L5 E o LE . JE AT M: E A CT 4a web 1[IN A (a a Sa \ 2162.0122 IR 3M MN01483123 a E 7; : d on iy i| Laeid) ia af Co Rae Rl a 4 CREE | {EER fae Ben NONE H=aAeNTvlE4S or | IE eran WPE EE : eei E"vTyE 8 Jj Hy -% Ge 2 | = IH, d i A od iN 2162.0123 3M MN01483124 4 Pal TE Ly gs g ED. AE dTA ALI PRE a Bc kn i da hn rn &(YrhW ole e BE SEE ;- EY EN i] 2 2 i+ I ey & aa GH waa WL sanert] is BE FE pe = 4 1 Hl uySl " Tas fl pa 3 ae | HE ET Eiq | & SE EE IB : - | gr &| Wl a al Br a 7) 4d % a hi | ls oN EE {-- 22116622..00112244 3M MN01483125 Ne J u iN a Tasruat aly Hf or. ERY fLH ITT i oWe ap CLAEE ami # | owog vB EES SS A he hooo REE A 3 NAa pif a. 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O- 0.5 ft. 0.5- 5 ft. Average PFBS (ppb, rig/g) ND ND NR ND ND ND NR NR NR NR ND ND ND NR NR Average PFHS (ppb, ng/g) 0.388 ND ND ND ND ND ND 0.783 0.447 0.227 0.154 ND ND 1.98 1.38 Average PFOS (ppb, ng/g) 66.9 11.5 7.66 1.17 0.247 ND 0.929 60.4 1.14 ND ND ND ND 161 318 Average PFOA (ppb, ng/g) 6.16 0.774 0.540 3.95 6.44 3.14 0.321 12.5 16.8 1.89 1.28 0.460 0.511 7.94 15.2 CGMN-SBC-MW105-0-0050 CGMN-SBC-MW105-0-0100 rsa CGMN-SBC-MW105-0-0150 Snes CGMN-SBC-MW105-0-0200 i CGMN-SB-MW106-0-0000 ei CGMN-SBC-MW106-0-0005 Sonam CGMN-SBC-MW106-DB-0005 |CCOGMMNN--SSBBCC--MMWW1160.60-D8.B0-0005500"(1)| Dame CGMN-SBC-MW106-0-0100 Soneee CGMN-SBC-MW106-0-0150 MW105 MW106 5- 10ft. 10 - 15 ft. pn] om | on| om | 15- 20 ft. pm] ow | ge | ie | G2 20 - 25 ft. Heme mie 0- 0.5 ft. ETT a | | 0.5- 5 ft. EC 0.5-5ff. 55-- 11001ft. sale lw] gas 10- 15 ft. mela 8oR | |m= E|u| 0|mB 15- 20 ft. 0.283 0.536 0.276 NR 0.475 NR NR NNRR NR NR NR 5.81 0.706 ND 2.00 61.8 47.7 2211.11 70.3 299 NR 27.8 1.16 0.672 47.6 653 599 116633 115 NR 205 74.6 5.27 0.690 13.5 185 145 114422 2080 5760 CGMN-SBC-MW106-0-0200 CGMN-SB-MW107-0-0000 Gm CGMN-SBC-MW107-0-0005 ecient CGMN-SBC-MW107-0-0050 Erihiow CGMN-SBC-MW107-0-0100 Sms CGMN-SBC-MW107-DB-0100 Sn CGMN-SBC-MW107-0-0150 Sie CGMN-SBC-MW107-0-0200 LLL CGMN-SB-MW108-0-0000 Sees CGMN-SBC-MW108-0-0005 SER CGMN-SBC-MW108-0-0050 Se CGMN SBC MW108 0 0100 So seine CGMN-SBC-MW108-0-0150 ne CGMN-SBC-MW108-0-0200 Sone CGMN-SBC-MW108-DB-0200 hl CGMN-SB-MW109-0-0000 aa CGMN-SBC-MW109-0-0005 maint CGMN-SBC-MW109-0-0050 Sone CGMN-SBC-MW109-0-0100 nee CGMN-SBC-MW109-0-0150 Seane soeas CGMN-SBC-MW109-DB-0150 IMW107 MW108 MW109 20 - 25 ft. 0- 0.5 ft. SEE | 2 | = 0.5- 5 ft. cat wg | B= 5- 10 ft. A 10- 15 ft. gale | w= ow 10- 15 ft. pa ow | Bam |e 15- 20 ft. aml ow | ow me oK 20 - 25 ft. EAR 0- 0.5 ft. SEE a [2 | 0.5- 5 ft. par | om | | =| 5- 10 ft. sale Ea 10 15ft. FE -A 15- 20 ft. aloe as | 2 | a 20 - 25 ft. aE] oe [ae] om| @ 20 - 25 ft. EB 1 0- 0.5 ft. TE Toe [a | ik 0.5- 5 ft. Fe II I I 5- 10ft. so om |e] om |e 10- 15 ft. eB as | 2 | 15- 20 ft. ppaar leom e|m |eom | 2|e 15-20 ft. 139 0.424 NR 1.75 126 127 NR 10.1 NR 0.295 NR NR ND ND ND NR NR NR NR NR NR 3470 1.78 14.5 NR 221 NR 315 122 0.475 0.450 0.787 1.38 0.789 0.319 0.314 0.516 0.409 0.202 0.682 0.892 0.951 35700 81.6 256 730 24200 26600 104000 57000 209 230 130 20.3 23.0 12.2 11.3 55.0 82.2 9.39 10.2 12.7 16.6 21800 15.0 232 139 1390 1850 NR 2340 3.02 NR 63.3 46.5 18.1 5.93 6.04 2.37 1.42 0.564 6.57 7.55 9.64 CGMN-SBC-MW109-0-0200 20 - 25 ft NR 1 81 every etme mtpnese re (1)Sample is a prima~y sample but was incorrectly listed as a field duplicate sample in the laboratory data package fe bgs = Below ground surface TE E et e ree ND = Not detected at or above Limit of Quantitation (LOQ) ef 0.25 ng/g 146 3O 7 NR = Not reported due 1o quality control failures. 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Soll Boring PES, PHS, POS and PFOAConcentrations Soil Boring PFBS, PFHS, PFOS and PFOA Concentrations Sune2006 June 2006 Sample ID TIRE CGMN-SB-D5B01-0-0000 CaNsac Dsa0t bouts CGMN-SBC-D5B01-0-0005 Cou Soc Dsanr.o00eD CGMN-SBC-D5B01-0-0050 comnsoc osonroooee| CGMN-SBC -D5B01-DB-0050 CaNSBCDE301 0010 CGM N-SBC-D5B01-0-0100 Sansa bemor oreo CGM N-SBC-DSBO1-0-0150 peeviverssestvotin] CGMN-SBC-DSB01-0-0200 CR SRR 50 CGMN-SB-D5B02-0-0000 CanSec 05am 00S CGM N-SBC-D5B02-0-0005 CAUNSoC 0020000| CGM N-SBC-DSB02-0-0050 Caunsec osars000 CGMN-SBC-DSB02-0-0100 Caunsec pearsoor CGMN-SBC-DSB02-0-0150 Casa Doane00000 CGM N-SBC-DSB02-0-0200 COMMSSO CGMN-SB-D5B03-0-0000 Case psa 000s CGM N-SBC-D5B03-0-0005 CRUNSBC 003000 | CGM N-SBC-DSB03-0-0050 Caunsec psarmo0iD CGMN-SBC-DSB03-0-0100 Cansec psamooren CGM N-SBC-DSB03-0-0150 Sansa Deana 0000 CGM N-SBC-DSB03-0-0200 COM SEOR00 CGMN-SB-D5B04-0-0000 Case Dsa0s 0000s CGM N-SBC-D5B04-0-0005 Sansa peant pote CGM N-SBC-DSB04-0-0050 Camsocosmmoow| CGMN-SBC-DSB04-0-0100 Causa bsant00rd CGMN-SBC-D5B04-0-0150 Prmeseni CGMN-SBC-D5B04-DB-0150 pry CGM N-SBC-D5B04-0-0200 Co SoA 00 CGMN-SB-D5B05-0-0000 Cansecosmsoons| CGM N-SBC-D5B05-0-0005 aunSoc Deans oven CGM N-SBC-D5B05-0-0050 Co Soe 500 CGMN-SB-D5B06-0-0000 Casa peas 00s CGM N-SBC-D5B06-0-0005 COUNSOC 053080000| CGM N-SBC-D5B06-0-0050 Cansac dszoe00r00 CGMN-SBC-D5B06-0-0100 Cause Dsanno0red CGMN-SBC-D5B06-0-0150 Cause Deane 00000 CGM N-SBC-D5B06-0-0200 EHSe CRE 50000 CGM N-SB-D9B01-0-0000 Casa Dean boos CGMN-SBC-D9B01-0-0005 Cau SacDoaot 000k CGMN-SBC-D9901-0-0050 Comsacomeoroeoo | CGMN-SBC-D9B01-DB-0050 Caunsec 0520100100 CGM N-SBC-D9B01-0-0100 Cau sac demot 00rd CGM N-SBC-D9B01-0-0150 SanSec Deni poo CGMN-SBC-D9BO1-0-0200 Se|A oe Sample Location sex | oEsSooEnrn |||I oONmmee ||| B tidmmw |||Bmvomeee ||| Besa2ise2s D5B01 oon | sovEwBSosoohfsoLosennnnn||||| ooow|wsreoee |||||| BeosdaGedoerw7rses ||||||Ba mwcawdmwuesee |||||| esoaoSeomsse7s) DSB02 peony | swTioSoosooRnnsn||||| ooowTszeRRes ||||| ecccsvoeeenamss | |||| Smuv1wae ||||| mi7osSeeeeese DSB03 oom | mviTwsoiioToosanSnnan||||| oMhOTsRmwW ||||| cCcccciaoeoasymnw ||||| 5Eswoew3sera ||||| Tza2eeeEw3mi D5B04 oseos | wohposae-nsnsnnn||| TowdWMvmeee |||| ccctTeereaonre |||| 7osemoxoos ||| 7ewro D5B05 peony | wDbsSoetesofannhn|||| otMR NwoRars ||||rwaa1emm7s|||| eGs maess |||he3mm7e2 D5B06 oor | mmswBDTsSoroiioeooeoaoannnnnnnnn||||||| oT2SohNwavmu%vwaReoeee |||||||| SomdmmwwTrsweeeoes ||||||| F[Ymo[wmwoeaemmsmeerene| | ||||| oaBs[=eoGmeewsmwememws D9B01 Sample Depth (bgs) 0- 0.5 ft. 0.5- 5 ft. 5- 10ft. 5- 10ft. 10- 15ft. 15- 20 ft. 20 - 25 ft. 0- 0.5 ft. 0.5- 5 ft. 5- 10ft. 10- 15 ft. 15-20 ft. 20 - 25 ft. O- 0.5 ft. 0.5- 5 ft. 5- 10 ft. 10- 15 ft. 15-20 ft. 20 - 25 ft. O- 0.5 ft. 0.5- 5 ft. 5- 10 ft. 10- 15 ft. 15-20 ft. 15-20 ft. 20 - 25 ft. O- 0.5 ft. 0.5- 5 ft. 5- 10 ft. 0- 0.5 ft. 0.5- 5 ft. 5- 10ft. 10- 15 ft. 15- 20 ft. 20 - 25 ft. 0- 0.5 ft. 0.5- 5 ft. 5- 10 ft. 5- 10 ft. 10- 15 ft. 15-20 ft. 20 - 25 ft Average PFBS (ppb, rig/g) NR 0.396 NR NR NR NR 0.283 ND ND 0.397 0.284 0.244 0.269 NR 0.938 NR NR 0.467 NR NR NR NR NR NR NR ND 0.912 NR 0.487 NR NR 1.67 NR 0.262 ND 0.370 1.14 NR NR NR NR 214 Average PFHS (ppb, ng/g) 0.215 1.26 1.53 1.12 4.09 6.00 1.68 0.438 1.79 10.7 6.65 15.3 9.91 0.314 0.422 0.272 0.683 0.344 0.382 0.437 0.592 0.673 0.815 0.917 0.869 0.661 ND 1.66 1.70 2.17 3.71 4.12 18.45 20.1 0.395 NR 39.0 23.2 20.5 418 472 29 2 Average PFOS (ppb, ng/g) 16.1 112 338 298 143 43.6 9.94 58.3 1640 2650 322 28.1 3.15 12.7 116 140 133 37.3 33.3 32.3 301 147 52.6 85.0 89.0 38.7 9.25 59.2 269 395 293 66.6 247 128 20.7 54.9 1560 154 176 29500 27800 1960 Average PFOA (ppb, ng/g) 2.57 62.8 53.6 41.5 68.9 146 29.2 5.72 29.2 88.5 62.3 186 2OO 1.80 16.8 29.4 17.5 9.20 6.90 3.13 2.81 8.08 21.3 16.7 17.0 25.7 0.587 18.8 31.5 15.5 33.2 33.7 33.4 108 13.3 25.3 2860 3210 3080 8890 10700 965 J---- bgs = Below ground surface ND = Not detected at or above Limit of Quantitation (LOQ) of 0.25 ng/g Reh eo ars NR = Not reported due lo quality control failures. Confidential - 3M z ~=OLDERS.0-9~3m-co~age grove~Phase 2 FC Confdential- 3M IInnssuurraannccee DDooccuummeennttss Data Assessment Repolt'Figures-Tables~Section 4 =igures & Tables~Se~tion4Tables-AII.xls 22116622..00113311 33MM_EENNVV_0000000033220077 S_MNOtE3N2 3M MN01483132 Tiere Table 4-3 (cont.) starr Ia S roscoe Soil Boring PFBS, PFHS, PFOS and PFOA Concentrations _. Sample ID TE CGM N-SB-D9B02-0-0000 fea CGM N-SBC-D9B02-0-0005 Quisommens| CGM N-SBC-D9B02-0-0050 Sheen CGMN-SBC-D9B02-0-0100 Ea CGMN-SBC-D9B02-0-0150 na CGM N-SBC-D9B02-O-0200 CGMN-SB-DgB03-0-0000 GoCGM N-SBC-D9B03-0-0005 Gales CGM N-SBC-D9B03-0-0050 momen| | CGMN-SBC-D9B03-0-0100 Ea CGMN-SBC-D9B03-0-0150 oe) CGMN-SBC-D9B03-DB-0150 Sg CGM N-SBC-D9B03-0-0200 La CGM N-SB-D9B04-0-0000 ShCGM N-SBC-D9B04-0-0005 usomons| CGM N-SBC-D9B04-0-0060 Qin CGMN-SBC-D9B04-0-0100 S iisheoos CGMN-SBC-D9B04-0-0150 Sample Location D9B02 D9B03 D9B04 CGM N-SBC-D9B04-0-0200 June 2006 - - Sample Depth (bgs) er pu 0- 0.5 ft. Fl I I 0.5- 5 ft. ener] de | cm | om | de 5- 10ft. sa Bm |B a 10- 15 ft. eal oe | em| ow] om 15- 20 ft. igi =| 2 @ 20 - 25 ft. 0- 0.51t rE Te [ne 0.5- 5 ft. carlo | am | om | 5- loft. 30] dn | 05 | | AE 10- 15 ft. pr] ce em || 15-20 ft. pa oe ld| os | am 15-20 ft. am] on || ox | om 20 - 25 ft. SL ETSa Eae O- 0.5 ft. | 5 0.5- 5 ft. loner) ox | a | mn | om 5- 10 ft. sa oR | EB] = 10- 15 ft. ea 5 | 2 | om | oe 15-20 ft. aml oe |e | we] 20 - 25 ft. Average PFBS (ppb, ng/g) NR ND ND ND ND ND NR 0.639 NR 0.803 NR NR 0.218 NR 5.85 NR NR NR NR Average PFHS (ppb, ng/g) 1.64 0.935 1.91 2.62 0.662 1.46 0.914 2.22 6.05 0.725 0.733 0.485 0.488 8.84 52.7 17.6 150 88.9 14.0 Average PFOS (ppb, ng/g) 70.1 123 78.0 60.8 15.4 39.7 131 145 6.54 1.01 9.05 6.30 2.26 663 391 3390 9960 4210 1060 Average PFOA (ppb, ng/g) 15.9 4.68 25.6 38.9 8.55 19.9 3.40 41.4 45.9 0.283 1.37 0.895 0.0620 32.6 390 1320 13400 1200 265 a, bgs = Below ground sudace ND = Not detected at or above Limit ol Quantitation (LOQ) ot 0.25 ng/g NR = Not reported due lo quality control failures. 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{i 33MM_EENNVV_0000000033221133 sw_oss13s 3M MN01483138 Porewate PFE, PFOA, PBTTSaa,bblleeF4H-9S9 and PFOS Concentrations Porewater PFBA, PFSOeAp,tPeFmBbS,ePrFOHcStaonb2d0e0Pr6FOS Concentrations September/October 2006 Sample ID oe Sample Location AVG PFBA (ppb, ng/mL) AVG PFOA (ppb, ng/mL) A~/G PFBS (ppb, ng/mL) AVG PFHS (ppb, ng/mL) AVG PFOS (ppb, nglmL) CGM N-IW-M RIW01-0-060912 IW01 ND 0.0850 ND [cou D%0vts Tver|xToo ToTho Toe CGM N-IW-M RIW02-0-060913 IW02 N R 0.0565 N D [Commisoo0vte wsJoosTotoToToToni] CGMN-IW-MRIW03-O-060914 IW03 0 0979 0 120 ND [coun waRMoE soos | wee| WR TossTho Ito Toor CGM N-IW-IVlRIW04-0-060914 IW04 NR 0.0543 ND ND 0.0509 N D 0.652 ND 0 114 ND 0.0457 CGM N-IW-M RIW05-0-060914 [FccunwiiRiceDos0sti|e{ots oosse to Tho Tost | CGMN-IW-MRIW06-0-060914 [FSourIwweri|iWmoTvoioeTro oo Tot0 oT sw ts| CGM N-IW-M RIW07-0-060913 [Counce sos0staTwos|pToossToTho 1 ooare | CGM N-IW-M RIW08-0-060913 Cou wiEWos3 6031s ITwos TorTe WT tw too CGM N-IW-M RIW09-0-060919 [Foor oss oo1o0 woes {NkTis Ser[3617e CGM N-IW-M RIW09a-0-061003 [Cots costoos wes |--1seTos TtTmTomi | CGM N-IW-M RIW09b-0-061003 [Feu HRIAGS: T05T003 |--Twise{0510T0573 Novos |oes | CGMN-IW-M RIW09c-0-061003 [Focu|n woom s|Rot1w z oNs o s | o No[shioc |oWos| CGM N-IW-M RIW09d-0-061003 COUN IWNRWO3e 0051008|wisge| ose | NR Noh | oo omre | CGM N-IW-MRIW09e-0-061003 [FeeswimRmosrogeoes|too | Wx--ooser| WoTto 1 wo | CGMN-IW-M RIW09f-0-060919 [FecunwiRIG Goi00s | Wwio| We 87 v2 Toa |ose| CGM N-IW-M RIW10-0-061003 [FecuNWamp OveJw{v3 N&| NeTse | a0 CGMN-IW-MRIW11-0-060919 IW05 IW06 IW07 IW06 IW09 IW09a IW09b IW09c IW09d IW09e IW09f IW10 IW11 0.135 0.146 ND ND 5.01 NR 1.58 0.510 0.112 0.0898 NR NR 103 0.0327 0.0498 0.0429 0.0505 2.69 21.5 0.586 0.573 ND NR 0.0541 8.12 NR ND ND ND ND NR 0.654 NR ND ND ND ND 1.23 NR ND ND ND ND NR 3.18 NR 0.0540 ND ND ND 0.488 5.65 0.0382 0.0517 NR 0.0270 1.09 2.69 0.114 0.166 ND 0.0278 ND 0.0550 14.0 CGM N-IW-M RIW12-0-061003 IW12 NR NR 0.1555 ND ND CGM N-IW-M R IW13-0-060921 [Fcoun-wamiepososz | wie{ge | 0|ze0 | ses | 2c | CGMN-IW-MRIW14-0-060921 [Foun Rws0050621| wias |g |weo | 15[2a | is | CGM N-IW-M RIW14a-0-060921 [FCoE0080621| wiiah|gTag Tee s11s 23 CGM N-IW-M RIW14b-0-060921 [FegumwaRTEs cos0071| twiae --|--751-- srs [teTx CGM N-IW-M RIW14c-O-060921 [ecu RwTEscoos]wires {oo TTThoTo] CGM N-IW-M RIW14d-0-060921 [Cou RWTEs0050521 | wide| WeTo Noto | ous | CGM N-IW-M RIW14e-0-060921 [FocusamRwRarogedgar| tanar {0178 >No to 1 Wo CGM N-IW-M RIW14f-0-060921 cE I CY J 1RSBSE CGMN-IW-MRIW15-0-060921 [FeounwiiRiTe-po00sts | wie{ado[ome | WT to | wo CGMN-IW-MRIW16-0-060915 [Fcour|twiwr--a| iikmv5i%TzswoeT0o0e0 s |s1t00e| CGMN-IW-MRIW17-0-060915 [Fecu|nw- isJwWa RTRsIoEDomcrToo0 s s|i20s| CGM N-IW-M RIW18-0-060915 [FccuN| -wiw e{a6sRTiaT mse|-W D[076a0w1WRs| CGMN-IW-MRIW19-0-060915 IW13 IW14 IW14a IW14b IW14c IW14d IW14e IW14f IW15 IW16 IW17 IW18 IW19 183 281 935 695 73.1 0.282 NR 0.178 81.1 4.40 NR NR 86.6 48.5 300 699 436 12.9 ND ND ND 12.2 0.250 2.15 2.06 28.9 N R 24.0 113 68.2 1.81 ND ND ND 2.01 NR 0.106 0.361 NR 2.55 8.66 27.4 14.8 NR ND ND ND NR ND 0.163 0.493 1.74 1.52 12.4 31.3 12.2 NR ND 0.0522 ND 0.0511 ND 1.32 2.91 N R CGM N-IW-M RIW19a-0-060919 [reunvwRwios Gosooto | wide{WeJie | m | ses | 1 | CGM N-IW-M RIW19b-0-060919 [coursecosooto | wise| WR | sas | are | ia | we | CGM N-IW-M RIW19c-0-060919 [coun RwWiss005001s | wigs| Tdo over | 5its[oro |over| CGM N-IW-MRIW19d-0-060919 [rec RTWTsec8051s| wiise{0706 No WTto Tox CGM N-IW-M RIW19e-0-060919 Ce 72 TOE TE GS CZ ES 0 CGM N-IW-M RIW19f-0-060919 [FecuJmww{a v0RTz wn i-p NeToso0i0 Tomes CGM N-IW-M RIW20-0-060915 [FeouNwaRmzTD%0wE|r|WeTis --9meTomo10m CGM N-IW-M RIW21-0-060915 [FawRRizzDp0wTs |--Twer{WRTKR oz Toe12m CGM N-IW-M RIW22-0-060915 [FeouwiimizDo005ts as|r[7s 73[3% | 150 CGM N-IW-M RIW23-0-060915 [FcomwamvizeoooostsTwas | vseTsTw1x CGM N-IW-M RIW24-0-060915 [ComwivzEsoos wes {ete em 1 se 1 sw] CGM N-IW-M RIW25-0-060915 IW19a IW19b IW19c IW19d IW19e IW19f IW20 IW21 IW22 IW23 IW24 IW25 172 NR NR 1.40 0.108 118 150 NR N R 139 157 23.1 NR 118 34.3 0.184 ND 6.84 88.1 1.50 N R 78.6 758 129 16.8 5.69 4.74 0.106 NR 3.14 NR 0.138 0.283 7.23 16.3 4.26 4.82 3.64 1.26 0.110 ND 0.504 6.01 0.120 0.299 3.15 309 3.86 47.0 53.1 NR 0.0813 0.257 1.71 0.635 0.150 2.40 15.0 NR 206 U1R0 = ikroetepcreddtuaroshnoveyacocnraeo1ese0.0 ND = Not detected at or above acceptable LOQ. NR = Not reported due to quality control failures. 64-66 CCoonfnifddeentnitaiall-- 33MM z \FOLDERS.0-9~3m-coltage grove'Phase 2 FC IInnssuurraannccee DDooccuummeennttss Data Asses~nlent Repolt'~=igures-Tables\Seclion 4 Figules & Tables~Section4Tables-AII.xls 22116622..00113388 33MM_EENNVV_0000000033221144 IM_MNO1483130 3M MN01483139 Table 4-10 omSSe EEron ro noone Mississippi River Sediment (Porewater Locations) PFBA, PFOA, PFBS, PFHS and PFOS Concentrations September 2006 [oe Je EEE EE|ea SampleID Sample Sample Interval Location Average PFBA (ppb, ng/g) Dry Weight Average PFOA (ppb, ng/g) Dry Weight Average PFB8 (ppb, ng/g) Dry Weight Average PFH8 (ppb, ng/g) Dry Weight EE] Average PFO8 (ppb, ng/g) Dry Weight [numerCoosHl[wo |Them| | | |w |% | CGMN-SD-MRIW011-0-060914 IW01 0 - 4 inches ND ND ND ND 0.458 CGMN-SD-MRIW012-0-060914 4 - 8 inches ND ND ND ND ND CGMN-SD-MRIW021-0-060914 IW02 0 - 4 inches ND ND ND ND 0.321 CGMN-SD-MRIW022-0-060914 4 - 8 inches ND ND ND ND ND CGMN-SD-MRIW031-0-060915 0 - 4 inches ND ND ND ND 0.363 EE CGMN-SD-MRIW032-0-060915 CG M N-S D-M RIW033-0-060915 CGMN-SD-MRIW041-0-060914 CGM N-S D-M RIW042-0-060914 CGMN-SD-MRIW051-0-060914 CGM N-$D-M RIW052-0-080914 CGMN-SD-MRIW061-0-060914 IW03 IW04 IW05 4 - 8 inches 14 - 18 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches eH ND 0.645 ND ND 0.493 ND ND ND ND ND ND ND kiD ND ND ND 0.255 ND ND 0.427 ND ND ND ND ND ND 0.230 ND 2.91 ND 0.320 ND 1.00 ND 0.489 CGMN-SD-MRIW062-0-060914 IW06 4 - 8 inches ND 0.298 ND ND 0.875 CG M N-S D-M RIW062-DB-060914 4 - 8 inches ND 0.249 ND ND 0.791 CGMN-SD-MRIW071-0-060914 IW07 0 - 4 inches ND ND ND ND 0.502 CGM N-SD-M RIW072-0-080914 4 - 8 inches ND ND ND ND ND [entree]vo[Siew| CGMN-SD-MRIW081-0-060914 CGM N-SD-M RIW082-0-060914 CGMN-SD-MRIW091-0-060915 CGM N-SD-M RIW092-0-060915 IW08 IW09 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches ND ND ND ND 0.753 [oa T T1%1 ND 0.291 0.238 ND 0.294 ND ND ND ND 0.589 4.15 2.08 ND ND NR Ce CGMN-SD-MRIW09a1-0-060918 CG M N-8 D-MRIW09a2-0-060918 CGMN-SD-MRIW0961-0-060919 CG M N-S D-MRIW09b2-0-060919 CG M N-S D-MRIW09b3-0-060919 CEE IW09a IW09b 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 14 - 18 inches NR 2.82 ND ND 2.16 11.2 12.7 2.75 ND 0.565 0.289 ND ND ND ND 1.08 0.952 ND ND ND 27.0 18.0 1.60 5.62 3.03 CG M N-S D-MRIW09c 1-0-060918 CG M N-8 D-MRIW09c2-0-060918 CGMN SD MRIW09dl 0 060918 Ea ib CN el CGMN-SD-MRIW09d2-0-060918 CG MN-SD-MRIW09e 1-0-060918 lemon worTsT CG M N-S D-MRIW09e2-0-060918 IW09c IW09d IW09e 0 - 4 inches 4 - 8 inches 0 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches ND 2.93 ND 6ND ND ND 0.508 NR ND TT ND ND ND ND ND 0.802 ND 0.237 0.230 ND ND 0.358 J ND ND 0.616 ND ND 0.279 0[08 To ND ND ND CG MN-SD-MRIW09f1-0-060918 IWO9f 0 - 4 inches ND ND ND ND 0.737 CG MN-S D-M RIW09f2-0-060918 4 - 8 inches ND ND ND ND 0.949 Edie [owTotem Ios ToTog T5 [or | CGMN-SD-MRIW101-0-060915 CGMN-SD-MRIW102-0-060915 CGMN-SD-MRIWl 11-0-060915 CGMN-SD-MRIW112-0-060915 IWIO I Wl 1 Q - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 100 124 NR 13.0 6 85 77.8 NR 12.4 ND 2.28 1.03 5.87 0 332 5.03 0.582 2.45 1 37 5.48 4.84 20.1 CGMN-SD-MRIW121-0-060915 IW12 0 - 4 inches 2.03 2.39 ND CGMN-SD-MRIW122-0-060915 4 - 8 inches NR 1.64 ND ND 4.12 ND 0.720 CGMN-SD-MRIW131-0-060915 0 - 4 inches ND 0.646 ND ND 3.62 CGMN-SD-MRIW132-0-060915 IW13 4 - 8 inches 15.3 6.67 0.846 ND 1.14 CGMN-SD-MRIW133-0-060915 CGMN-SD-MRIW141-0-060915 isommwnsooms]"0|Toews| mo |om | te | te |om| CGMN-SD-MRIW142-0-060915 CGMN-SD-MRIW14a1-0-060919 [omit arocmenlme|Sona |S| we | wa [vs | we | CGMN-SD-MRIW14a2-0-060919 CGMN-SD-MRIW14b1-0-060919 lemma weTien Tod TSFTo TOF13 CG MN-SD-MRIW14b2-0-060919 CGMN-$D-MRIW14c1-0-060919 JesselweTg | 3 07 Tf[5 135 | CGMN-SD-MRIW14c2-0-060919 CG MN-SD-MRIW14dl-0-060919 emis we | Si | 8 [oom1%[8| 3% 1 CG MN-SD-MRIW14d2-0-060919 IW14 IW14a IW14b IW14c IW14d 19.5 - 24 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 10.1 ND 27.3 62.2 18.6 12.5 264 64.5 87.8 ND ND NIR 1.34 2.34 126 33.5 23.8 341 106 78.1 ND 0.396 0.384 ND 1.30 11.1 3.41 1.58 29.4 8.27 10.5 ND ND ND ND ND NR 1.13 0.693 11.5 4.61 3.28 ND ND 0.483 4.20 0.785 74.5 11.6 NR 38.3 10.4 11.0 ND ND CGMN-SD-MRIW14e1-0-060919 IW14e 0 - 4 inches ND owen ve| vie | te CG MN-SD-MRIW14e2-0-060919 4 - 8 inches ND [aomme]TM | eee| te CGMN-SD-MRIW14fl -0-060919 IW14f 0 - 4 inches ND CG MN-SD-MRIW14f2-0-060919 4 - 8 inches NR ND ND TT 0T [w| ND ND ND ND | ow | to | tw | Se | 0.322 ND ND ND ND ND ND 0.513 ND ND ND = Not detected ~t or sbove the ~ccept~ble LOQ. NR = Not reported due to quality control failures. DB = Field duplicate sample Confidential - 3M insurance Documents 22116622..00113399 3IMM_EENNVV_0000000033221155 3M MN01483140 resSe mESiEm mma Table4-10 (cont.) Mississippi River Sediment (Pore Water Locations) PFBA, PFOA, PFBS, PFHS and PFOS Concentrations [oeSample ID JeSample Location Sample Interval EEE September 2006 Average PFBA (ppb, ng/g) Dry Weight Average PFOA (ppb, ng/g) Dry Weight er|ea Average PFB8 (ppb, ng/g) Dry Weight Average PFH8 (ppb, ng/g) Dry Weight aE] Average PFO8 (ppb, ng/g) Dry Weight Be~ CGMN-SD-MRIW151-0-060915 CGMN-SD-MRIW152-0-060915 CGMN-SD-MRIW161-0-060915 CGMN-SD-MRIW162-0-060915 CGMN-SD-MRIW163-0-060915 IW15 IW16 e0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 16- 20 inches [ZNR 93.2 ND 1.87 NR TS12.3 95.1 0.222 0.398 0.459 CTC 0.446 ND NR 3.41 ND ND ND ND ND ND [meme]we Tas To To CGMN-SD-MRIW171-0-060915 CGMN-SD-MRIW172-0-060915 CGMN-SD-MRIW181-0-060915 CGMN-SD-MRIW182-0-060915 IW17 IW18 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches ND ND ND 0.336 0.361 1.05 0.649 2.41 ND ND T 6Tg T ND ND ND ND ND ND CGMN-SD-MRIW191-0-060915 0 - 4 inches ND 1.02 ND ND IW19 CGMN-$D-MRIW192-0-060915 4 - 8 inches ND 1.26 ND ND CGMN-SD-MRIW19a1-0-060918 CGMN-SD-MRIW19a2-0-060918 IW19a 0 - 4 inches 4 - 8 inches 40.9 104 9.82 26.0 2.25 5.54 0.505 1.17 CG MN-SD-MRIW19b1-0-060918 CGMN-SD-MRIW19b2-0-060918 IW19b 0 - 4 inches 4 - 8 inches ND 1.26 1.34 4.86 ND ND ND 0.612 1.31 ND 0.654 ND ND 1.47 55NR 3.17 5.19 3.53 NR 44.3 79.0 6.86 34.7 CGMN-SD-MRIW19cl-0-060918 CGMN-SD-MRIW19c2-0-060918 CG M N-S D-MRIWl 9d 1-0-060918 CGMN-SD-MRIW19d2-0-060918 CGMN-SD-MRIW19e1-0-060918 CGMN-SD-MRIW19e2-0-060918 CGMN-S D-MRIW19fl-0-060918 CGMN-SD-MRIW19f2-0-060918 IW19c IW19d IW19e IW19f 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 0 - 4 inches 4 - 8 inches 1.65 28.2 ND ND ND 0.539 20.4 70.1 NR 27.6 ND 0.459 ND ND 10.7 42.7 ND 0.894 ND ND ND ND 1.47 NR ND 0.869 ND ND ND ND 0.280 1.89 1.61 ND 0.295 ND 0.535 ND 1.42 0.937 CGMN-SD-MRIW201-0-060915 CGM N-SD-M RIW202-0-060915 EEE CGMN-SD-MRIW211-0-060915 CGMN-SD-MRIW212-0-060915 CGMN SD MRIW221 0 060919 CGMN-SD-MRIW222-0-060919 CGMN-SD-MRIW223-0-060919 IW20 0 - 4 inches 4 - 8 inches 3.41 26.9 0.296 1.39 Eee IW21 IW22 0 - 4 inches 4 - 8 inches 0 4 inches 4 - 8 inches 19.5 - 23.5 inches ND ND 0.609 0.436 1.71 0.221 0.492 0.714 2.31 2.94 ND ND 1.42 0.569 ND 3.86 Ee ND ND 0.215 ND ND ND ND ND ND 0.430 1.35 2.54 NR 7.91 29.1 CGMN-SD-MRIW231-0-060918 CGM N-SD-M RIW232-0-060918 CGMN-SD-MRIW241-0-060918 [eon anc] | aimee| ome | 3m |Cw | CGMN-SD-MRIW242-0-060918 CGMN-SD-MRIW251-0-060916 [En rooms|ve | one| 3% | te | tu | CGMN-SD-MRIW252-0-060918 IW23 IW24 IW25 0 - 4 inches 4 - 8 inches 0 - 4 inches 16 - 20 inches 0 - 4 inches 4 - 8 inches NR 53.4 1.22 0 345 NR 35.3 3.10 32.0 5.96 3 44 67.0 130 1.40 3.97 0.274 ND 1.06 1.14 0.742 1.77 1.55 ame | 0 634 5.36 ox | 6.01 17.4 59.4 30.7 ne | 24 0 NR ws | 168 ND = Not detected at or above the acceptable LOQ. NR = Not reported due to quality control failures. Confidential - 3M insurance Documents 22116622..00114400 33MM_EENNVV_0000000033221166 3M MN01483141 hey tspRe ace tr PestSo emc mFeAAnr ,FsOR) ,PFBS, PPS 1PROS Conettins Table 4-11 Mississippi River Surface Water (Porewater Locations) PFBA, PFOA, PFBS, PFHS and PFOS Concentrations September/October 2006 Sample ID CGMN-SW-MRIV~O11-0-060912 [wo TETST 2 TST T | CGMN-SW-MRIVe)12-0-060912 CGMNSW-M RIW021-0-060913 [woTST 2To [0T3535| CGMN-SW-MRIVe)22-0-060913 CGMN-SW-M RlWO31-0-060914 [wo [08[8a[25| 8[25 | CGMN-SW-MRIVe)32-0-060914 Sample Location IW01 IW02 IW03 Sample Depth (ftow) 2 feet 8 feet 1.5 feet 6.5 feet 1.5 feet 4.5 feet Average PFBA (ppb, ng/mL) ND ND ND NR NR ND Average PFOA (ppb, ng/mL) ND ND ND ND ND 0.0518 Average PFBS (ppb, ng/mL) ND ND ND NR NR ND Average PFHS (ppb, ng/m~ ND ND ND ND ND ND Average PFOS (ppb, ng/mL) ND ND ND ND ND ND CGMN-SW-M RIVe)41-0-060914 1.5 feet ND 0.0608 ND ND ND IWQ4 CGMN-SW-M RIVe)42-0-060914 5 feet ND 0.0551 ND ND ND CGMN-SW-M RIW051-0-060914 1.5 feet ND ND ND ND ND [wee[ol 8T 6[28 108 [3| IW05 CGMN-SW-M RIV'~52-0-060914 5 feet ND ND ND ND ND CGMNSW..M RIW061-0-060914 2 feet ND 0.0557 ND ND ND [weeJo I 8To"[20 1 5[3| IW06 CGMN-SW-M RIW062-0-060914 5 feet ND ND ND ND ND CGMN-SW-M RIVe) 71-0-060913 2 feet ND ND NR ND ND CII N = IW07 CGMN-SW-M RIW072-0-060913 8 feet ND ND ND ND ND CGMN-SW-M RIW091-0-060913 2 feet r'4R ND NR ND ND IW08 CGMN-SW-M RIW082-0-050913 8 feet NR ND NR ND ND CGMN-SW-MRIW091-0-060919 2.8 feet 1.24 0.192 NR NR 0.162 EN elIE I II IW09 CGMN-SW-MRIW092-0-060919 11 feet r'4R 0.187 NR 0.104 0.183 CGMN-SW-MRIW09a1-0-061003 2 feel NR ND NR ND ND [wwJR TSTo[8T 8[3| IWO9a CGM N-SW-MRIW09a2-0-061003 8 feet ND ND ND ND ND CE S I S CGMN-SW-MRIW09b1-0-061003 IWO9b 3 feet ND ND ND ND ND CGMN-SW-MRIW0962-0-061003 11 feet ND 0.530 NR ND ND CGMN-SW-MRIW09c1-0-061003 3 feet ND ND ND ND ND IW09c CGMN-SW-MRIW09c2-0-061003 11 feet NR 0.543 ND ND ND CGMN-SW-MRIW09d1-0-061003 2.4 feet NR 0.0649 NR ND ND IWO9d CGMN-SW-MRIW09d2-0-061003 10 feet ND NR NR ND ND CGMN-SW-MRIW09e1-0-061003 2 feet NR 0.0671 ND ND ND CEE I I IWO9e CGM N-SW-MRIW09e2-0-061003 7 feel ND ND ND ND ND CGMH-SW-MRIWOgf1-0-060919 IV~gf 1.4 feet 0.405 ND NR ND ND [oon[i 65 Tote[a| 5[3| CGMN-SW-MRIW09f2-0-060919 5.8 feet 0.477 0.0535 0.168 ND ND CGMN-SW-MRIW101-0-061003 4 feet ND ND ND ND ND [woToT2To [2T=[5| IW10 CGMN-SW-MRIW102-0-061003 14 feet NR 0.0750 NR NR NR CGMN-SW-MRIW111-0-060919 cGMr'4-SW-M RIW112-0-060919 CGMN-SW-M RIW121-0-051003 [weTomI 2ToTeI [5| CGMN-SW-M RIW122-0-061003 CGM N-SW-M R IW131-0-060921 EENrl Oo 0I I CGM N-SW-M RIW132-0-060921 CGM N-SW-M RIW141-0-060921 EII N I I I CGM N-SW-M RIW142-0-060921 CGM N-SW-MRIW14al 43-060921 [weTim 181om [ir | 200[50| CGM N-SW-MRIW14a2..e-060921 IW11 IW12 IW13 IW14 IW14a 3.4 feet 13.4 feet 4 feet 16 feet 3.8 feet 15 feet 3.7 feet 14.8 feet 1 foot 4 feet 2.58 1.30 ND N D 0.604 N R 0.414 NR N R NR 0.323 NR ND ND 0.0740 0.0654 0.0532 0.0566 NR 0.760 0.889 NR ND ND NR 0.216 0.159 NR 0.371 0.481 NR NR ND ND NR ND ND NR 0.0626 0.0763 NR 0.113 ND ND 0.0539 0.0594 NR ND 0.111 0.130 CGM N-SW-MRIWI 4bl ..0-060921 CGM N-SW-MRIW1462-0-060921 CGM N-SW-M RIW14cl -0-060921 CGM N-SW-MRIW14c2-0-060921 ICI EII 2 feet N R 0.195 0.237 ND 0.0631 IW14b 8 feet 0.540 0.158 0.219 ND 0.0578 3 feet 0.394 NR NR ND ND IW14c 13 feet 0.305 NR 0.137 NR NR CGM N-SW-MRIWI 4d 1 ..0-060921 1.4 feet 0.329 ND 0.129 ND ND IW14d CGM N-SW-M RIW14d2-0-060921 5.5 feet 0.318 ND 0.135 ND ND CIN P I 3I CGMN-SW-MRIW14e1-0-060921 1.3 feet 0.0641 0.0538 NR ND ND IW14e CGM N -SW-M RIW14e2 -0-060921 5.3 feet N D ND ND ND ND CGMN-SW-M RIW14fl-0-060921 1.5 feet ND ND NR ND ND IW14f CGM N-SW-M RIW14f2-0-060921 6.1 feet ND ND ND ND ND CGM N-SW-M RIW151-0-060921 CGMN-SW-MRIW152-0-060921 CGM N-SW-M R I W101-0-060915 [weTiti 5To8[0[oso [05 | CGMN-SW-M RIW162-0-060915 CGMN-SW-M RIW171-0-060915 ETI NI AI I CGMN-SW-M RIW172-0-060915 CGM N-SW-M RIW131-0-060915 ETI NII I CGM N-SW-M RIW132-0-060915 IWl 5 IWl 6 IW17 IWl 8 2.1 feet 8.4 feet 1.3 feet 5.2 feet 0.8 feet 3.4 feet 0.8 feet 3.4 feet NR 0.326 N R NR 0.660 0.562 N R NR 0.153 0.0845 0.198 0.150 0.144 0.145 0.149 0.142 0.198 0.136 0.149 NR 0.136 0.123 0.126 0.117 ND ND ND 0.0591 ND ND ND ND 0.0602 ND NR 0.155 0.116 0.122 0.115 0.110 CGM N-SW-M RIW191-0-060915 0.9 feet N R 0.119 0.113 ND 0.105 IWl 9 CGM N-SW-M RIW192-0-060915 3.5 feet NR 0.126 NR NR 0.0966 ND = Not detected at or above the acceptable LOQ listed for each analyte. The ~ssessed accuracy, cf the ND results associated with LOQs of 0.100 ng/mL is 100% 50%based on the proxircit~, of the 0.100 ng/nlL LOQ to the 0250 ng/rnL field spike concentration. The assessed accuracy of other reported results is 100% +/- ~,0%. NR = Not reported due to quality control failures. Confidential - 3M Insurance Documents 33MM_EENNVV_0000000033221177 S3M_MMNN01O48E3144N22 22116622..00114411 hey tssme ec pgsnEiemrsest noone Table4-11 Mississippi River Surface Water (Pore Water Locations) PFBA, PFOA, PFBS, PFHS and PFOS Concentrations September/October 2006 Sample ID CGM N-SW-MRIW19al -0-060919 Ee EleTll e CGM N-SW-MRIW19a2-0-060919 CGM N-SW-MRIW1961-0-060919 me ET TreTeTa CGMN-SW-MRIW19b2-0-060919 am ETE erTE CGMN-SW-MRIW19cl -0-060919 CGM N-SW-MRIW19c2-0-060919 Sample Location IW19a IW19b IW19c Sample Depth (ftow) 1.1 feet 4.4 feet 0.9 feet 3.6 feet 0.9 feet 3.6 feet Average PFBA (ppb, ng/mL) NR 4.28 2.81 1.96 NR 0.981 Average PFOA (ppb, ng/mL) 0.231 0.246 0.154 0.129 0.0699 0.0726 Average PFBS (ppb, ng/mL) NR NR NR 0.831 0.546 0.413 Average PFHS (ppb, ng/mL) 0.438 0.472 0.312 0.201 0.117 0.0950 Average PFOS (ppb, ng/mL) 0.214 0.206 0.127 0.0889 0.0545 NR CGM N-SW-MRIW19dl -0-060919 1.2 feet 0.0949 ND ND ND ND IW19d CGM N-SW-MRIW19d2 -0-060919 4.6 feet 0.117 ND ND ND ND CGM N-SW-MRIW19el -0-060919 1.9 feet NR ND NR ND ND m ETEr TETETT IW19e CGM N-SW-MRIWl 9e2-0-060919 7.4 feet ND ND ND ND ND CGM N-SW-MRIW19fl -0-060919 2.3 feet 0.245 ND 0.0924 ND ND me ET TRTer 2 IW19f [TS OE oe [e we | CGMN-.SW-MRIVV19f2-0-060919 9 feet 0.516 NR NR NR ND CGMN-SW-MRIW201-0-060915 CGMN-SW-M RIW202 -0-060915 [Ee CGMN-SW-MRIW211-0-060915 CGMN-SW-M RIW212 -0-060915 CGMN-SW-MRIW221-0-060915 CGMN-SW-M RIW222 -0-060915 CGMN-SW-MRIW231-0-060915 CGMN-SW-M RIW232-0-060915 IVV20 IVV21 IW22 IVV23 0.9 feet NR 0.145 0.180 0.0558 0.112 3.6 feet NR 0.154 NR NR 0.118 EETTETTerTEETET 0.9 feet 3.6 feet 1.2 feet 4.9 feet 1.7 feet r'4R NR NR r'4R 6.92 0.530 0.535 0.611 NR 0.438 2.27 2.28 2.46 2.35 NR 0.820 0.855 0.886 0.862 0.708 0.413 0.436 0.523 0.539 0.323 6.7 feet 6.76 0.435 1.96 0.694 0.350 CGMN-SW-MRIW241-0-060915 CGMN-SW-M RI~V242-0-060915 IW24 1 foot 4 feet 1.16 NR 0.141 NR 0.247 3.05 0.0781 1.04 0.114 0.466 CGMN-SW-M RIW251-0-060915 IVV25 0.4 feet NR CGMN-SW-MRIVV252-0-060915 1.6 feet NR 0.163 0.146 0.207 NR 0.0661 0.0729 0.0945 0.102 ND = Not detected at or above the acceptable LQ listed for each analyte The ~ssessed accuracy, cf the ND results associated with LQQs of 0 100 ng/mL is 100% +/50%based on the proxircit~, of the 0.100 rig/rilL LOQ to the 0250 ng/rnL field spike concentration. The assessed accuracy of other reported results is 100% +/- 50%. NR = Not repoEed due to quality control failures. ConfidahiaiTM Si Tnsirancs Documents 22116622..00114422 owen omszio 3M ENV 00003218 mere 3M MN01483143 ~Z ~ [ite be ZZ | fret ZZZZ {AEMaeitnroaini ZZ li| | sri ee ~,4~~ ..... oooo mn Li i zzzzzz Confdential ~ 3M Insurance Documents 2162.0143 3M ENV 00003219 3M MN01483144 pos i Src aro dT or PFOA, PFOA, FBS,PENS 10d FOS Cancntotions Table 4-13 Mississippi River Surface Water (Longitudinal and Transect Locations) PFBA, PFOA, PFBS, PFHS and PFOS Concentrations October 2006 Sample ID [-- erm Tory eet-- Tw--T-- wT --w ] CGM N-SWC-MRLS784a3-0-061005 Foner rse eeToair eoTo 5 CGM N-SWC-MRLS78463-0-061005 ESE or mt a tn) e | CGM N-SWC-M R LS784c3-0-061005 F ht e oe Fe a CG MN-SWC-MR LS7853-0-061005 FemmesseeHee ee ee CG MN-SWC-MR LS7883-0-061005 Fents emPe arm e+ eom Hoe Hee +s 2 CG MN-SWC-M RLS7913-0-061005 Fess hen ee CG MN-SWC-M RLS7943-0-061005 CG MN-SWC-M RLS7973-0-061004 Fee ee Ho+o CGMN-SWC-M RLS8003-O-061004 Fo eebes an s H+ e CGMN-GWC-M RLS8033-0-061004 Smeea EE ani ee eeu] CGM N-SWC-M RLS8063-0-061004 Foneees Baan HeH+ CGMN-SWC-M RLS8093-0-061004 Femme seee See ee] CGMN-SWC-M RLS8123-0-061004 Fens en Pe erunm teeaH mee Hee +e CGMN-SWC-MRLS8153-0-061004 Famer eeHere +o CGMN-SWC-M RLS8183-O-061003 Fe en m Pei mes CGM N-GWC-M RLS8213-0-061003 F--e -- n tes a tne L)C tm e+-- a 1o s -- o e1 -- e CGMN-SWC-MRLS8243-0-061003 Sample Location LS-784a LS-784b LS-784c LS-785 LS-788 LS-791 LS-794 LS-797 LS-800 LS-603 LS-806 LS-609 LS-812 LS-815 LS-818 LS-621 LS-824 Sample Depth " tftw)(1) Average PFBA (ppb, ng/mL) Average PFOA (ppb, ng/mL) Longitudinal Sample Locations 1.3 ft / 5.2 ft 0.0790 0.0693 1.2 ft / 4.7 ft ND NR O.66 ft / 2.6 ff 0.0530 ND 3.0 ft/12 ft ND 0.0751 3.1 ft/12.4 ft ND ND 2.4 ft / 9.6 ft ND 3.7 ft / 14.6 ft ND ND 2.2 ft / 8.6 ft ND ND 1.3 ft / 5.3 ft ND ND 3.4 ft / 13.6 ft ND ND 2.6 ft / 10.4 ft ND 0.0508 3.4 ft / 13.6 ft 0.0565 ND 3.0 ft / 12.5 ft 0.0562 ND 3.6 ft / 14.4 ft 0.0705 ND 3.8 ft/15ft ND ND 2.2 ft / 8.8 ft ND ND 2.5 ft / 9.8 ft ND ND Transect Sample Locations Average PFBS (ppb, ng/mL) NR NR NR ND ND ND ND ND NR ND ND NR NR ND ND NR ND Average PFHS (ppb, ng/mL) NR ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND Average PFOS (ppb, nglmL) ND NR NR ND ND ND ND ND ND ND ND ND ND ND ND ND ND CGMN-SW-M RXS01a1-0-061003 XS-01a 0.5 ft ND ND ND ND ND CGMN SW MRXS01a2 0 061003 1.8 ff ND ND ND ND ND [Conroe| = | tan | to | w | to | tw | uw | CGMN-SW-M RXS01 bl-0-061003 XS-01 b 1.2 ff ND ND ND ND ND CGM N-SW-M RXS01 b2-0-061003 4.6 ft ND ND ND ND ND CGM N-SW-M RXS01c~.-0-061003 XS-01c 1.0ft ND NR ND NR ND [ee omsmcne ztonm [oeoeo |h on The Te pToe To] e Te | CGMN-SW-M RXS01d1-0-061003 XS-01d 1.0 ft ND NR ND ND ND CGM 1"4-SW-M RXS01 d2-0-061003 4.0 ft ND ND ND ND ND [eons [oor| 3a| he 10Tip To| 42 | CGMN SW MRXS01el 0 061003 XS-01e 0.9 ff N~ ND ND ND ND CGMN-SW-M RXS01e2-0-061003 3.7 ff ND ND ND ND ND CGM N-SW-M RXSO2a0-0-061002 0.Oft NR ND NR ND NR cham |-[Blg[B[l R[a 8| CGM N-SW-M RXS02a 1-0-061002 XS-02a 4.5ft NR ND ND ND ND CGM N-SW-M RXS02a2-0-061002 17.5 ft NR NR NR ND ND CGMI"4-SW-M RXS02b0-0-061002 0.0ft ND ND ND ND ND CGMN SW MRXS02bl 0 061002 XS-02b 0.75 ft N R ND ND ND ND CGM N-SW-M RXS02b2-0-061002 3.0 ff ND ND ND ND ND CGM N-SW-M RXS02c0-0-061002 0.Off ND ND ND ND ND CGM N-SW-M RXS02cl-0-061002 XS-02c 1.0ft NR ND ND ND ND CGM N-SW-M RXS02c2-0-061002 3.7 ff ND ND ND ND ND CG M 1"4-SW-M RXS02d 0-0-061002 0.0 ft ND ND ND ND ND CGMN SW MRXS02dl 0 061002 XS-02d 0.7 ff ND ND ND ND ND CGM N-SW-M RXS02d2-0-061002 2.8 ff ND ND ND ND ND CGM N-SW-M RXSO2e0-0-061002 0.0 ff NR 0.199 NR ND ND CGM N-SW-M RXS02e 1-0-061002 XS-02e 0.7 ff ND ND ND ND ND CGM N-SW-M RXS02e2-0-061002 2.8 ff NR ND ND ND ND ema[en[ZnTeTwImTw i | CGM N-GW-M RX$03a 1-0061004 XS-03a 0.6 ft ND ND ND ND CGMN SW MRXS03a2 0 061004 2.2 ff ND ND NR ND ND [e [oo | iom r 10Toim [0Ta oT 20 | CGM N-SW-M RXS0361-0-061004 S-03b 1.0 ff ND ND ND ND ND CGM N-SW-M RXSO3b2-0-061004 4.0 ff ND 0~0501 ND ND ND CGM N-SW-MRXS03c1-0-061004 iio IE I IS I CGM N-SW-MRXS03c2-0-061004 XS-03c 3.5 ff 14ff ND ND ND 0.0523 ND ND ND ND =4-72 Confidential - 3M InsuranceDocuments 22116622..00114444 33MM_EENNVV_0000000033222200 W_MNOT4B1435 3M MN01483145 55.. SSUUMMMMAARRYY OOFF OOBBSSEERRVVAATTIIOONNSS The following sections provide an overview, by media and ara, of the findingsof the The following sections provide an overview, by media and area, of the findings of the Cotage Grove Ste Phase 1 and 2 FC assessments. This overview is presented to provide Cottage Grove Site Phase 1 and 2 FC assessments. This overview is presented to provide ffooccuuss oonn aarreeaassooff iinntteerreesstt tthhatt wwiillll bbee ffuurrtthheerr eevvaalluuaatteedd oass ppaarrtt ooff tthhee FFSS pprroocceessss.. DDeettaailleedd information on the Phase activites and rests is contained in the Fuorochenical (FC) DinaftoarmAsastieosnsmoenntthReePphoarste(1WEacStTivOiNti,es Aapnrdilre2s0u0l6t)s.is contained in the Fluorochemical (FC) Data Assessment Report (WESTON, April 2006). 55.11 GGRROOUUNNDDWWAATTEERR PPhhaasse 1e1 IInn PPhhaassee 11,, PPFFOOAA aanndd PPFFOOSS ccoonncceennttrraattiioonnss wweerree ddeetteecctteedd iinn ggrroouunnddwwaatteerr ssaammpplleess ffrroomm mmoonniittoorriinngg wweellllss MMWW--1122 ddoowwnnggraraddiieenntt oofftthhee DDS5--FFoorrmmeerr SSoolliiddss BBuurrnn PPiitt AArrceaa,, MMWW--1144 ddoowwnnggraraddiieennttooff tthhee DD38--FFoorrmmeerr WWaassttee DDiissppoossaall AArreeaa,, aanndd MMWW--110011 ddoovwgnrgardaideienntt oofftthhee DDI1--FFoorrmmeerr HHFF TTaarr NNeeuuttrraalliizzaattiioonn BBaassiinn aatt ccoonncceennttrraattioinons rraannggiinngg ffrroomm 115500 ttoo 11,586633 ppppbb aanndd ffrroomm 5800 t1o0 332244 ppppbb,, rreessppeeccttiivveellyy.. IItt mmuusstt bbee nnootteedd tthhaatt PPWW--6 iiss ddoowwnnggraraddiieenntt ooff tthhee DD58 AArreeaa aanndd iiss ccaappttuurriinngg tthhee aaffffeecctteedd ggrroouunnddwwataeterr.. TThhee ccoonncceennttrraattiioonn ooff PPFFOOAA ddeetteecctteedd iinn pprroodduuccttiioonn wweellll PPWW--66 wwaass 115555 ppppbb. identified for Phase 2. WWiitthh rreessppeecctt ttoo ggrroouunnddwwaatteerr aatt tthhee CCoottttaaggee GGrroovvee SSiittee,, tthhee ffoolllloowwiinngg ddaattaa nneeeeddss wweerree identified for Phase 2: + CCFhohararmraaeccrtteeSrrilizuzaadttgiieoonnDioosffpogrsoraoulunndPdivtwataeterr qquuaalilittyy nandd mmoovveemmeenntt iinn tthhee aarreeaa oofftthhee DDY9 Former Sludge Disposal Pit. + CpChaharariracacuctlteerrrliiyzzaadttioioownnngoorffadtthiheeenpptooottfeenntttiihaaellDmmS,oovvDeeSmm,eeannnttdooDff2ggrrAooreuuannsdd.wwaatteerr ttoo ssuurrffaaccee wwaatteerr,, particularly downgradient of the D8, D5, and D2 Areas. Phas2e Phase 2 IInn PPhhaasse2e2,, tthhee ffoolllloowwiinngg wwaass ffoouunndd:: = 1Dd)e99tecAAtrreeedaaat--cFFonCCcssenwwterearrteeioddneestteerccattneegddiniignn fggrrrooomuunn2dd9u.w7aat0tee.rr76aa.tt3tthphepeb.DDO9PFAAOrreAeaa..waPPsFFBdBeAAtecwwtaeasds 3124.6 ppb detected at at 24.6 ppb in MW-107 but was NR at MW-105 ard concentrations ranging from 29.7 to 76.3 in MW-107 but was Nil at MW-105 and MW-106, PFOS ppb. PFOA was MW-106. PFOS was NR detected was Nil Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 Report doc ---- "55-1 Confidential - 3M Insurance Documents Confdential- 3M Insurance Documents 33MM_EENNVV_0000000033222211 _MNOE45 3M MN01483146 22116622..00114455 WISE acattonsaallilldettrhherrdeeeetommqouonaninitttoiofrryiinntgghewwseeellrllesssuliintns ttshhoeethDDt99thAAeryreeama.a. yFFuburertthhueesrredaainnnaalltyyhsseeeessvawwliuillalltihbonee ocoMfofWana-lslti1tdee3mernraeaatdttiivvateoescsqoniuinncaenttnhthtieefryaFFtStSih.o.ensIIennofrPPehh1sa6ua.ssl5tees ps11,po,b.PPthFFTaOOht iSSthsewwwyaeaslsmldadeyietstebeccceritoeeusddsseagadttraimmndoiotnehnineitttooeorrviiannltgguhaewwtieDeol9lnl.l MAArrWeeaa-1tto3otthahtee awwecestos.tn. centration of 16.5 ppb. This well is cross gradient to the D9 * DDoowwnnggrraaddiieenntt ooff DDI1//DD22 AArreeaa,, W WWWTTPP PPoonnddss,, aanndd DDS5 AArreeaa DDI1 AArreeaa PoPfFFOO15AA0 wwpaapss addneetdteecc1tt6ee3ddpiipnnbP,Phhraaessspeeec1|tiwwveeellllylss. MMWW--110011 aanndd MMWW--110022 aatt ccoonncceennttrraattiioonnss of 150 ppb and 163 ppb, respectively. DD22 AArreeaa PPcoFFnOcOeAAntwwraaatssioddneesttoeeccfttee6dd1ii9nn MMppWWb--1a1n00d334aa1nn4dd pMMpWbW,--1r1e00s4p4ecddtooiwvwenlngygr.raaddPiieFenBnttAooffwtathhsee dDDe22teAActrreeedaa iaantt McMoWWn-c-1e1n00t33rataaitto3n311s88oppfpp6bb19aannpddpwwbaasasnNNdRR41aa4tt MMpWpW-b1:-01r40e4.sp. ePPcFFtiOOveSSlyww.aaPssFNNBRRAiinnwbbaoostthhdewwteeelclltless.d in WWWWTTPP PPoonnddss DDcooonwwcnegnnrgtarraadtdiiieeonnntot fooff21tth9heeppWWb.WWPTTFPPOAppooannndddss,,PFPPOFESBBAAwerwweaassNRddeeattteeccMttWeed-d1ii0nn8,MMWW--1100S8 aatt aa concentration of 219 ppb. PFOA and PFOS were NR at MW-108. DDs5 AArreeaa PDPuFFrOOiAAngwwPaahssasddeeettee2cc,tteePddFiiOnnAPPhhwaaassees 11dewwteeellcllteMMdWW-in-112M2Waa-tt 1aa0cc9oonnc(cesenhntatrlraalttoiiwoo)nn aoonffd11.,M886W633-1pppp1bb0. D((ddueereeippn))gaattPcchooannsceceenn2t,trraaPttFiiooOnnssAoofwf 1a19s999dppepptbebcaatennddd 1i1n3366MppppWbb,-,1rr0ee9ssppee(ccsithivavelellloyy.w. ) and MW-110 + HtThiyeddrprouolmloopggiiinccgaallofIInntttweeorrppprrreeottdaauttciitooinnon-- wTTehhleelsaa(rreePaaW-ooSff ggarrnooduunnPddWww-a6at)teerrwaccsaappettsuutrrieemaiintndedduuccbeeydd tbbhyye tiiehnnletteeevrprapputrrimeeottnpaaittcniioogonnntoooofufftrwggmorraooppuu.rnnoddTdwwhuaecattteipeorrrnojeewelleceetvvleaaldtstiiow(oPnniW ddtdah-a5totaafacbbnayydptPccuW oornnes-st6terr)xuuwtccettaininsdngsgeseataismggtrraototoeuudnnMddbWwwy-aat1tthee2err ieiCnnolevtvethh.aeetioTDDnhS5ecoAAnarrneteoaaaul,,yrsaamennsaddpi.wwneTdesihsctteatttpoeoroatajheappctotoeiitndnhttewmmipdiiutddhmwwpoaaiyfyncgabbpeeotttwufwreeePeeWnenx-tP6PeW Wnsd--es55rveeaaassnntddttootthhMceeaWpW Wte-ues1rst2et roundwater from the DS Arec Cove. The analyses indicate that groundwater from the D5 Area. the pumping of PW-6 serves to capture IIannnalaayddsddeiisttiiooonnf pttoooretthwhaeetehhryyddsrraoomllpooglgieicscaallfreeovvmaalltuuhaaettiiMooinns.,sittshhseeippllaiabbooRrriaavtteoorrryyalrrseeossuuslluttpsspoffrootrr tFFhiCCs fafpiirnnneadddliiiynncsggte.esdFFoCzCfopncceooornneoccwfeenancttatrerparatttuiisoroaennmss(pIlddeWees-tt1eefccrttoteeomdd TiitWnhn-e8tth)hMeeiisnppsdooiirsrcseeaiwwtpaepatticeeorrRncillvoeonecctraarttiaaiotlosninoossnssuwwpoiiptfthhoiPirnntFOttthShhi.ese PpiPnrFFetOdOhiAeActDeaadSnnddzAorPPneFeBaBAAogrfoaacuttanplldeetwvuvaeerletlsse(rssIWii(ggMnn-iW1iff-ii1ctcoa2ann,IttWllyyM-Wl8lee)-sss1sin0ttdhh9iaacnnaatnttehdheecMoccWnoo-ncn1cec1ene0ntnrt)atr.rtaaitotiiFnooosnnrssoefddxeeaPttmFeepccOltteeSe.dd, titPhnhFeetOhmmeAaaDx(x15iim.m8Au6umr3meapFFpgCbCroaucctnooMdmmWwpp-oaotu1uenn2rdd(iMnddeWePtthee-acc1stt2eee,ddM1)ii.nnWwgg-hr1reoo0ruu9ennadadswnwadPatFtMeeOrrWAaa-ttw1a1tthsh0ee).nDDoFtS5odreAAetrrexeecaaatmewdwpalaeissn, PpipomoFrmrOeeewwdAaiata(tete1rer,8l6yss3aamdmpopppwlblneegssartacMcdooilWlellene-cct1tt2eeoddifnfftPrrhohoemamsDelSlo1occ),aaAttwriieoohann.essreaMl1isWWsPs--iF77sOsioAoprrpwi1IaWWRs-i-8nv8,oe,rt dwwpehhotieircccehhtweadtaaerirnere iccmoonnmcceeendntitraraatettiiloyonnssdoaawtt nllogoccraaatdtiiiooennnsst ooouufttsstiihddeee oDoff"5tthhAeerepparr.oojjeeMccttiesedsdiszzsooipnnpeei ooRffivccaaepprttuuprroeere((wIIWaNt--e99r Z:\FOLDERS.0-9\3rn-cottage 9rove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuuorrmaannccee DDooccuummeenntt2ss5-2 33MM_EENNVV_0000000033222222 I3MM_MMNNO011448833114477 22116622..00114466 through IW-25) are higher than concentrations detected at locations IW-1 through IW-8 inside the predicted zone of capture (see Figures 4-13 to 4-15). The hydrogeological and analytical data collected at the site support the conceptual site model which indicates that groundwater beneath the site flows towards and discharges to the Mississippi River. The capture zone created by tthhee ppuummppiinnggooff PPWW--55 aanndd PPWW--66 iinntteerrcceeppttss ggrroouunnddwwaatteerr iinn tthhee wweesstteerrnn ppaarrtt ooff the site before it discharges to the river. On the eastern portion of the site (east of the D5 Area) the groundwater flow is not intercepted and it discharges to the river. 55..22 SSoOIlILL geste 55..22.11 DD11//DD22 AArreeaa --- FFoorrmmeerr HHFF TTaarr NNeeuutrtraalliizzaattiioonn BBaassiinn//FFoorrmmeerr SSlluuddggee Disposal Area PPhhaasse 1e1 IInn tthhee DD22 --- FFoorrmmeerr SSlluuddggee DDiissppoossaall AArreeaa,, FFCC ccoonncceennttrraattiioonnss uupp ttoo 1122,,335500 ppppbb PPFFOOSS were found in the sludge, which is located approximately 5 ft to 20 ft bgs. Lower concentrations (ranging from 4.39 to 794 ppb PFOS) were detected in the underlying native soil, which begins at approximately 20 to 25 ft bgs. In the D1 - Former I-IF Tar Neutralization Basin Area, FC concentrations up to 4,520 ppb PPFFOOAA wweerree ddeetteecctteedd iinn tthhee 55 ttoo 3300 ffit bbggss ddeepptthh rraannggee iinn bboorriinnggss ccoonnssttrruucctteedd jjuusstt oouuttssiiddee the suspected location of the basin structure and decreased below 30 ft bgs in the native soils (ranging from 53.9 to 375 ppb). I~ower levels of PFOS and PFOA were detected m the deepest interval sampled in the D1 Area at 65 to70 ft bgs and in the D2 Area at 45 to 513 ft bgs. The depth to groundwater in tthhiiss aarreeaa iiss aapppprrooxxiimmaatteellyy 7777 fftt bbggss.. Phase 2 Soil samples collected during the installation of Phase 2 monitoring wells MW-104 and MW-105, downgradient of the D2 Area, indicated PFOA and PFOS at significantly lower Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt7ss535-3 22116622..00114477 33MM_EENNVV_0000000033222233 3M MN01483148 ccoonncceennttrraattiioonnss tthhaann ssaammpplleess ccoolllleecctteedd ffrroomm wwiitthhiinn thhee ffooooptprriinntt oofftthhee DD11 aanndd DD22 AArreeaass iinn PPhhaassee 11.. FFCCsswweerree ddeetteecctteedd uupp ttoo 6666..99 ppppbb ((PPFFOOSS aatt 00--00.55 fftt bbegss)). 55..22..22 DD55AArreeaa --- FFoorrmmeerr SSoolliiddss BBuurrnn PPiitt AArreeaa Phases Phase I IInn tthhee DDS5 ---FFoorrmmeerr SSoolliiddss BBuurmn PPiitt AAvreesa,, ccoonncceennttrraattiioonnss ooff PPFFOOSS ((uupp t1o0 22,331l00 ppppb)) aanndd PPFFOOAA ((uupp 1to 11,,337755 ppppbb)) wweerree ddeetteecstteedd iinn ssooiill ssaammpplleess ttoo 3a ddeepptthh oofafpapprporoxxiimmatateellyy 1155 fft basin the one soi boring (SB DSO) consinueted in this rea. Lower concentrations were bgs in the one soil boring (SB D501) constructed in this area. Lower concentrations were ddeetteecctteedd aatt lloowweerr ddeepptthhss,, bbeellooww 1155 ffeeeett ((uupp ttoo 4466..88 ppppbb PPFFOOSS aanndd uupp ttoo 4422..55 ppppbb PPFFOOAA).). Phase? Phase 2 TThhee rreessuultss ooff PPhhaassee 22 ssooiill ssaammpplliinngg iinntthhee DDS5 AArreea iinnddiiccaattee tthhaatt FFCCss wweerree ddeetteecctteedd nneeaarr tthhee ssttoorrmmwwaatteerr rreetteennttiioonn bbaassiinn iinn tthhee ssoouutthhwweesstt ppoorrttiioonn ooff tthhee DDS5 AArreeaa aanndd tthhaatt hhiigghheerr lleevveellss aarree iinn aa llooccaalliizzeedd aarreeaa ((ii..ee..,, 11--22 bboorriinngg llooccaattiioonnss)).. FFCC ccoonncceennttrraattiioonnss uupp ttoo 22,,665500 ppb PFOS were detected in the 5-10 tbs sample interval at Phase 2 sil boring DSB02 pTphbe PhFigOhSeswt ePrheadseete2ctePdFiOnAtheco5nc-1e0ntfrtatbigosnsafmorpltehiisntaerrevaalaaltsoPhwaasse 2destoeicltbeodriinng tDi5sBs0o2il. Tbohienhgigahte2s0t0Phpabse i2n tPhFeO2A0-2c5onftcebnstraitniotenrvaflo,r ththis daercepaesatlsiontewrvaasl dseatmepclteedd. inPFthOiSs asonidl bPoFrOinAg aart 2t0h0e pprpibmairnythFeCs20d-e2t5ectftedbgins tihneteDrvSalA,rtehae deepest interval sampled. PFOS and PFOA are the primary FCs detected in the D5 Area. SSaammpplleess ffrroomm tthhee rreemmsaiinniinngg ffoouurr PPhhaassee 22 ssooill bboorriinnggss sallssoo iinnddiiccaatteedd ddeetteeccttiioonnss ooff PPFFOOSS (9:25 10 395 ppb) and PFOA (0.387 t0 146 pp) but at ower concentrations than near the (r9et.2e5ntitoon39b5aspinp.b) Tanhde PPFhOaAse 2 soil (13.587 to b1o4r6inpgpsb) (bDuStBaOt IlowaenrdcoDnSceBnStr)atioinnsditchaatnednealrowtheer rceotnecnetinotnatboanssion.f FTChse thPahnasPehas2e1sosiolilbboorriinnggs SB(DD5SBO011, wahnidchDii5nBt0h3e) sinadmiecaatred. lower concentrations of FCs than Phase 1 soil boring SB D501, which is in the same area. Based on the Phase 2 sil boring logs from five sail borings, thre ws no definzbl soil BhoarsiezdonosnitnhdeicPahtiavsee o2fssoliuldbgeo,rinasghloorgsotfrhoemr dfiisvpeosseodil mbaotreirniagls., tThheereswoiasinnothdeefDinSabAlreeasoiils hproirmizaorinlsyinsdanicdatwiivtehoifnstleurdbgeed,deadshsiotr aonthdercldayisploensseeds.mAafteerriald.isTphoesasloialtiinvtihiesDi5n AthreeaDiSs pArriemaawrielyresdainsdcowntiithnueind,tertbheedadreeda wsialtsarnedporctlaeydlylencsoevse.reAdftweirthdi3sptoosa7lfeaecttiovfiitliel.s iBnatsheedDo5n Athreeabowrienreg dloisgcsonthtienuielld~latyheeracroeualwd ansotrebpeordtiesdtliyngcuoivsehreeddfwoimth n3attoiv7e fseeedtimoefntfisl.l. BHoasweedveorn tahteSbBo-riDnSgBlOoSgsathwehifitlle lacryyesrtacloluinlde nmoattebreialdisatisngueinschoeudnftreormedncaatiuvseinsgedtimheenbtosr.iHngowtoevbeer at SB-D5B05 a white crystalline material was encountered causing the boring to be Confidential - 3M Insuorm ance Document"sSa Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc 5-4 Confdential- 3M Insurance Documents 22116622..00114488 33MM_EENNVV_0000000033222244 W_MNOT1B49 3M MN01483149 terminated due to Geoprobe refusal. PFOS was detected at the 5-10 ft sample at a ccoonncceennttrraattiioonn ooff 226699 ppppbb.. TThheerree wweerree nnoo oorrggaanniicc vvaappoorr mmeetteerr ((OOVVMM)) rreeaaddiinnggss oobbsseerrvveedd at this location. OVM readings were observed at SB-D5B02 near the retention basin. WWiitthh tthhee eexxcceeppttiioonn ooff SSBB--DDSSBB0022,, FFCC ccoonncceennttrraattiioonnss ddeeccrreeaassee wwiitthh ddeepptthh aanndd aarree generally highest between 5 and 15 ft bgs. At SB-D5B02, PFOA was highest at the base of the boring (25 ft bgs) and PFOS was highest at the 5 to 10 ft bgs interval. Depth to groundwater in this area is approximately 90 ft bgs. A perched water table was encountered in one boring, MW-109, at approximately 40 ft bgs. pz55..22..33 DD99 AArreeaa-- FFoorrmmeerr SSlluuddggee DDiissppoossaall PPiitt Phase 2 SSooiill ssaammpplleess ccoolllleecctteedd ffrroomm tthhee nnoorrtthheerrnn aanndd eeaasstteerrnn ppaarrttss ooff tthhee DD99 AArreeaa dduurriinngg tthhee installation of MW-106, MW- 107, and soil borings SB-D9B01 and SB-D9B04 indicated FC concentrations up to 104,000 ppb PFOS (15-20 ft at MW-107). The soil boring logs indicated waste material was present and organic vapors were recorded at these locations to a maximum depth of 25 feet at SB-D9B01 and 21 feet at SB-DB04. The maximum depth sampled was the 20-25 ft bgs interval at each location. PFOS was detected in this ddeepptthh iinntteerrvvaall wwiitthh ccoonncceennttrraattiioonnssrarannggiinngg ffrroomm 11,,006600 ppppbb aatt SSBB--DD99BBO044 ttoo 5577.,000000 ppppbb aatt MW-107. As described in the boring logs for SB-D9B01 and SB-D9B04, visible waste material was encountered at a maximum depth of approximately 30 ft bgs. Organic vapors were observed at 16 feet down to approximately 79 ft bgs in the MW-106 boring. Visible waste material and organic vapors were not observed at SB-D9B02 and SB-D9B03. Groundwater is present at an average depth of 85 feet which is well below the depth of the encountered waste material. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt7ss5s5-5 22116622..00114499 33MM_EENNVV_0000000033222255 3M MN01483150 55..22.44 W Waasstteewwaatteerr TTrreeaattmmeenntt PPllaanntt AArreeaa PPlhaassee22 Soil samples collected during monicoring well MW-108 installation indicated cSoonicl entsarmatpiloenss ocfoPllFeOctSedrandguirnigngfrommon12it:o5ripnpgb (w20e-ll25 Mft Wbe-s1)008 2i3n0staplplabti(o0n5-5indfticbaytse)d cTohnecePntOraStioncsonocefnPtFraOtSionrsanginingsiflromat 1M2W5-1pp0b8(2d0e-c2r5eafstebgwsi)thtod2ep3t0h.ppDbet(0ec.5t-e5d PFOA ft bgs). coTnhceenPtFraOtSioncsornacnengetraftrioonms3.in02 ppsoil (a0t-0M.5Wt -b1e0s8) to 63.3 pp (5-10 tbs). decrease with depth. Detected PFOA concentrations range from 3.02 ppb (0-0.5t~ bgs) to 63.3 ppb (5-10 ft bgs). 55..22.55 FFiirree TTrraaiinniinngg AArreeaa TThhee FFTTAA iisuussedd ffoorr ffiirree ttrraaiinniinngg aanndd aann aaddjjaacceenntt rearea iis uusseeddaass a ccoonnttrraaccttoorr ssttoorraaggee aarreesa.. Phases Phase 1 In Phase 1, at the Fire Training Arca, PFOS was detected at concentrations up to 1.820 IpnobPhaprsiema1r,ialty inthe FsihrealTlorawinisnogilsArteoa, aPFdOepSthwaosfdeStefctedbeast, cownitchentsriagtnioifniscaunptlyto l1o,8we2r0 copnpcbenptrrimtiaorinlsy deintecstheadllaotwl-owseorildseptohsa depth of 5 ft bgs, with significantly lower concentrations detected at lower depths. Phase? Phase 2 Phase 2 sail samples were collcted from six hand auger locations. OF the 12 FC Pchoamspeou2ndssoialnaslaymzepdle,sthweeprerimcaorlylecFtCeds dfertoemctesdixinhtahned Pahuagseer2lopcraotgiornasm. eOrfethPeFO1S2 aFnCd cPoFmOAp.ouTnhdes raensaullytzseodf,tthhee Pphriamsear2y sFaCmpsldientgecptreodgirnamthseiPndhiacsaet2thpartoPgrFaOmSwwearse dPeFteOcStedanadt PFOA. The results of'the Phase 2 sampling programs indicate that PFOS was detected at llooccaattiioonn FFTTAA0066 ((22--33 ffit)) wwiitthh aa ccoonncceennttrraattiioonn ooff 22,,994488 ppppbb.. TThhiiss ssaammppllee wwaass ccoolllleecctteedd from a drainage swale south ofthe lined holding pond. During Phase 1, the highest PFOS ~om a drainage swale south of the lined holding pond. During Phase 1, the highest PFOS concentration (1,820 ppb) was detected at SS FTA02. This sample was collcted from concentration (1,820 ppb) was detected at SS FTA02. This sample was collected from drainage swale at the southeast comerofthe FTA are just prior o the tree fine where a drainage swale at the southeast corner of the FTA area just prior to the tree line where a nnaattuurraall ddrraaiinnaaggee sswwaallee bbeeggiinnss.. SSiinnccee tthhee PPhhaassee 1| ssaammpplliinngg,, tthhiiss aarreeaa hhaass bbeeeenn rree--ggrraaddeedd ttoo improve drainage by the construction of the ne stormwater runoff detention basin improve drainage by the construction of the new stormwater runoff detention basin. Phase 2 samples collcted from this area (FTA) indicated lowe PFOS concentrations ranging from 23.3 ppb to 145 ppb (0-1 ) Phase 2 samples collected from this area (FTA08) indicated lower PFOS concentrations ranging from 23.3 ppb to 145 ppb (0-1 ft) Confidential - 3M Insurance D--ocument"sSo Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc 5-6 Confdential- 3M Insurance Documents 22116622..00115500 3MM_ENEVN_V0000000033222266 W3M_MNMON1041B4833115511 re" Samples collected from other drainage swales near the lined holding pond (FTA04 and FFTTAAO0S5)) iinnddiiccaatteedd PPFFOOSS ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 445588 ppppbb ((FFTTAA00S5,, 00--11 ff1t)) ttoo 11,.002266 ppb (FTA04, 0-1 ft). PFOS was also detected from a sample (FTA09) collected just off of a concrete pad used for fire training. A concentration of 747 ppb was detected in the 0-1 ft sample. A deeper sample could not be obtained with a hand auger due to large gravel that was encountered. The FC results from the FTA sampling indicate that: Higher FC concentrations are typically found in localized areas of drainage The higher concentrations are typically found in the shallow and surficial soils = AAddddiittiioonn ooff ssooiillss aanndd eeaarrtthh ddiissttuurrbbaannccee aarroouunndd tthhee nneeww ssttoorrmmwwaatteerr bbaassiinn (during construction) has resulted in lower concentrations 5.3 EAST COVE Based on the physical characterization and the analytical results from the Phase 1 and Phase 2 FC assessments conducted in the two acre East Cove, the following key observations can be made: Surface Water There is a continuous flow- of water through the cove due to the Cottage Grove planntt coooolliinngg wwaatteerr and WWWWTTPP dischargee,, sttoorrmmwwaatteerr ddiisscchhaarrggee ffrroomm tthhee plant and run-off from the cove drainage area during storm events. + OOFf tthhee 44 FFCC ccoommppoouunnddss aannaallyyzzeedd dduurriinngg tthhee PPhhaassee 11 aasssseessssmmeenntt,, tthhee hhiigghheesstt FC concentrations detected in surface water from the East Cove were PFOS and PFOA Concentrations of PFOS and PFOA detected in surface water samples collected at the East Cove inlet from the Phase 2 assessment were less than those detected from the Phase 1 assessment; however, concentrations of PFHS and PHBS remained consistent. No significant differences in FC concentrations were detected between the Phase 2 surface water samples collected at the East Cove inlet and outlet locations. Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttNssz5-7 33MM_EENNVV_0000000033222277 3M MN01483152 22116622..00115511 No significant differences in FC concentrations were detected between the water surface and the 0.6 depth surface water samples collected at the Phase 2 East Cove inlet and outlet locations. Sediment Of the 4 FC compounds analyzed during the Phase 1 assessment and the 12 FC compounds analyzed during the Phase 2 assessment, the highest concentrations detected in sediment from the East Cove were PFOS and PFOA. A total of three distinct layers were observed in sediment cores collected from the East Cove as observed in 7 probe locations in the lower part of the cove. These layers consisted of a firm top fine granular layer, and middle semi-solid ffiinnee ssiilltt llaayyeerr ((wwhheerree aa bbllaacckk rreessiidduuee llaayyeerr wwaass eennccoouunntteerreedd)),, aanndd aa bboottttoomm sandy clay layer. The middle layer observed ranged from 2 inches to 2 feet in thickness, appearing to exist in pockets throughout the lower part of East Cove. This black residue layer was encountered at depths of 1.0 to 2.5 feet bbeellooww tthhee ttooppooftf thhee sseeddiimmeennt.t. * IInn ggeenneerraall,, ccoonncceennttrraattiioonnss ooff FFCCss,, ddeetteecctteedd iinn tthhee ttoopp llaayyeerr sseeddiimmeenntt ssaammpplleess collected from the East Cove are consistent between the Phase 1 and Phase 2 assessments. The highest concentrations of PFOS and PFBA (65,450 ppb and 94.6 ppb, respectively) were detected in the middle sediment layer where black residue was obselwed The highest concentration of PFOA 1~845 ppb was detected in the bottom sediment layer. 5.4 WEST COVE The West Cove is approximately one acre in size. It receives surface drainage from the Cottage Grove Site Contractor Storage Yard and the Fire Training Area from the northeast and from the area around the Eagle Point municipal sewage treatment plant (STP) to the west. The STP outfall discharges directly to the Mississippi River and does not enter the West Cove. The water in the West Cove is generally stagnant and flow vveelloocciittiieess wweerree nnoott mmeeaassuurarabblele.. Surface Water Surface water and sediment samples collected during Phase 1 and Phase 2 sampling programs indicate the detection of very low concentrations of FCs, priSmE arily PFOA and PFOS. Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss5-8 33MM_EENNVV_0000000033222288 3M MN01483153 22116622..00115522 PFOS was detected at a concentration of 1.7 ppb (0.5 It) at the Phase 2 upstream surface water sample location (WC-4). PFOS was also detected at a similar concentration (1.27 ppb) in the upstream Phase 1 surface water sample (WC-1). The Phase 2 surface water sample collected from the downstream discharge pooiinntt ((WWCC--88)) iinndicatteed a lloowweerr PFFOOS coonncceennttrraattiioonn ooff 00..224411 ppppbb ((wwaatteerr surface). PFBA was detected at this location at 1.01 ppb (0.5 ft). Sediment PFOS concentrations in the sediment samples ranged from 15.2 ppb (Phase 1, WC-3) to 137 ppb (Phase 2, WC-07). PFOA was also detected in sediment samples ranging from 11.2 ppb (WC-06, 0-6 in) to 15.9 ppb (WC-07, 13-6 in). No sludge/waste material or discolored sediment was encountered in West Cove sediments. 55..55 MMIISSSSIISSSSIIPPPPII RRIIVVEERR 5.5.1 Porewater Sampling Locations (Porewater, Sediment and Surface WWaatteerr)) At each of the 43 porewater sampling locations along the shoreline of the River, samples of porewater, sediment and surface water were collected and analyzed for the 12 FC compounds. The higher concentrations of these FCs were detected at three general areas for each of the media sampled: + IIWW--2222 ttoo IIWW--2255 aalloonngg tthhee eeaasstteerrnn ppoorrttiioonn ooff tthhee sshhoorreelliinnee nneeaarr tthhee EEaasstt CCoovvee (approximately 1,0013 feet) IW-19 transect along the eastern shore near the D1/D2/D9 Areas IW-14 transect near the WWTP area EEaasstteerrnn PPoorrttiioonnoofftthhee SShhoorreelliinnee Near the East Cove area, concentrations of PFOS, PFOA and PFBA were detected in both porewater (up to 206 ppb, 758 ppb and 157 ppb, respectively) and sediment samples (up to 168 ppb, 130 ppb and 53.4 ppb, respectively). In surface water, PFOS concentrations at IW-22 to IW-25 range from 0.0945 to 0.539 ppb. PFOA concentrations Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt"ss55-9 22116622..00115533 33MM_EENNVV_0000000033222299 3M MN01483154 range from 0.141 ppb to 0.611 ppb. For PFBA, 5 of the 8 samples were NR. CCoonncceenntrtraattiioonnss iinn tthhee rreemmaaiinniinngg tthhrreeee ssaammpplleess rraannggeedd ffrroomm 11..1166 ppppbb 0to.66..9922 ppppbb.. TTrraannsseeccttss TThhee ddeetteeccttiioonn ooff FFCC ccoonncceennttrraattiioonnss iinn ppoorreewwaatteerr aanndd sseeddiimmeenntt ssaammpplleess ccoorrrreellaattee cclloosseellyy and in general decrease with increasing distances from the shoreline (southerly) at the ttrraannsseecctt 1looccaattiioonnss ((IIWW--1199,, IIWW--1144 aanndd IIWW--99).). OOnnee eexxcceeppttiioonn ii ss aatt IIWW--1199ffwwhheerree ppoorreewwaatteerr ccoonncceennttrraattiioonnss ooff PPFFBBAA ddeeccrreeaassee bbeeyyoonndd IIWW--1199dd ((330000 fftt ffrroomm sshhoorree)) ((11..4400 ppppbb)) aanndd increase at IW-19f (500 ft from shore) to a concentration of 118 ppb. Sediment samples from these locations also exhibit a similar trend. The highest PFOS concentration detected in surface water was from location IW-13. Other locations where FCs are detected at higher concentrations in porewater and sediment are IW-11, IW-13 and IW-9a. These locations are east of D5 and west of the WWTP pond area. At the locations near the West Cove and Fire Training area (lW-1 to IW-7), PFOA and PPFFOOSS aarree tthhee oonnllyy FFCC aannaallyytteess ddeetteecctteedd iinn sseeddiimmeentn.t. PPFFOOSS wwaass ddeetteecctteedd aatt eeaacchh llooccaattiioonn and PFOA was detected at IW-3, IW-5 and IW-6. In the porewater samples, PFOS was detected only at IW-1, IW-2 and 1W-3. PFOA was detected at IW-1 to lW-6 and not ddeetteecctteedd aatt IIWW--77.. CCoonncceenntrtraattiioonnss ooff FFCCss iinn tthhiiss aarreeaa ((IIWW--11 ttoo IIWW--77)) wweerree ssiiggnniiffiiccaannttllyy lower than the eastern part of the shoreline The shoreline area within the zone of capture of production wells PW-6 and PW-5 is discussed in Subsection 4.2. The concentrations detected in porewater, sediment and surface water in this area are either not detected or very low. This indicates that FC concentrations in site groundwater are being captured in the area of PW-5 and PW-6 bbeeffoorree tthheeyy rreeaacchh tthhee rriivveerr.. Z:\FOLDERS.0-9\3rn-cottage prove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc or "Soo 5-10 Confidential - 3M IInnssuurraannccee DDooccuummeennttss Confdential ~ 3M 22116622..00115544 33MM_EENNVV_0000000033223300 3M MN01483155 5.5.2 Transect Locations SSeeddiimmeenntt aanndd ssuurrffaaccee wwaatteerr ssaammpplleess wweerree ccoolllleecctteedd ffrroloTml tthhee 33 ttrraannsseeccttss ((1133 ttoottaall sampling locations) across the Mississippi River. Also, water samples were collected at the water surface at the five locations along Transect XS-02. Sediment The river transect results indicate that PFOS was the only FC compound of the 12 analytes detected in sediment at a maximum concentration of 2.66 ppb (XS-2a). SSuurrffaaccee WWaatteerr Surface water sampling results indicate that PFOS was not detected in any of the samples. PFOA was detected in only three samples at a maximum concentration of 0.199 ppppbb ((XXSS--0022e)). PPFFBBAA wwaass nnoott ddeetteecctteedd iinn 2233 ooff 3300 ssaammpplleess ccoolllleecctteedd aatt tthhee 1133 llooccaattiioonnss.. NRs were reported for the remaining 7 samples. 55..5..33 LLoonnggiittuuddiinnaall LLooccaattiioonns Sediment and surface water samples were collected from 17 locations along approximately 40 miles of the Mississippi River from five miles upstream of the Cottage Grove Site and downstream to Lake Pepin. SSeeddiimmeenntt TThhee rreessuullttss iinnddiiccaattee tthhaatt oonnllyy PPFFOOSS aanndd PPFFOOAA wweerree ddeetteecctteedd iinn sseeddiimmeenntt ssaammppleless.. PPFFOOAA was only detected from the samples at the head of Lake Pepin ranging from 0.441 ppb to 11..0099 ppppbb.. PPFFOOSS wwaass ddeetteecctteedd iinn 1177 ooff tthhee 2266 ssaammpplleess ccoolllleecctteedd wwiitthh ccoonncceenntrtraattiioonnss. ranging l'rom 0.142 ppb to 3.16 ppb. PFBA was ND in 22 of the 26 sainples and NR in tthhee rreemmaaiinniinngg ffoouurr ssaammppleless.. Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeennttSsso 5-11 22116622..00115555 33MM_EENNVV_0000000033223311 3M MN01483156 SSuurrffaaccee WWaatteerr PPFEBBAA aanndd PPFFOOAA wweerree tthhee oonnllyy FFCCss ddeetteecctteedd iinn tthhee lloonnggiittuuddiinnaall ssuurref'aaccee wwaatteerr ssaammpplleess aanndd tthheessee ccoonncceennttrraattiioonnss wweerree vveerryy llooww.. PPFFBBAA wwaass ddeetteecctteedd iinn 5 ooff tthhee 1177 ssaammpplleess wwiitthh ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..00553300 ppppbb ttoo 00..00779900 ppppbb.. TThhee ootthheerr 1122 ssaammpplleess wweerree aallll NNDD.. PPFFOOAA wwaass ddeetteecctteedd iinn tthhrreeee ssaammpplleess wwiitthh ccoonncceennttrraattiioonnss rraannggiinngg ffrroomm 00..00550088 ppppbb t1o0 00..00775511 ppppbb.. TThhee ootthheerr 1133 ssaammpplleess wweerree NNDD aanndd oonnee ssaammppllee wwaass NNRR.. PPFFBBSS~, PPFFHHSS,, aanndd PPFOOSS wweerree teihtheerr NNDD oorr NNRR.. re Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss5-12 22116622..00115566 33MM_EENNVV_0000000033223322 I3MM_MMNNO011448833115577 66.. DDEEVVEELLOOPPMMEENNTT AANNDD SSCCRREEEENNIINNGG OOFF RREESSPPOONNSSEE AACCTTIIOONN AALLTTEERRNNAATTIIVVEESS IInn aaccccoorrddaannccee wwiitthh tthhee rreeqquuiirreemmeennttss ooff tthhee CCoonnsseenntt OOrrddeerr SSeeccttiioonn VVII aanndd EExxhhiibbiitt AA,, Section III.E.3, the development and screening of response action alternatives for the Site will be based on the List of Possible Technology Types, presented in the RI Report and FS Work Plan and approved by the MPCA Commissioner. The following section provides the List of Possible Technology Types for the Site and a description of the process that was used to develop this list. TThhee FFSS WWoorrkk PPllaann,, wwhhiicchh iiss bbeeiinngg ssuubbmmitittteedd ccoonnccuurrrreennttllyy wwiitthh tthhiiss rreeppoorrtt,, iinncclluuddeess aa description of how this list will be used to develop response action alternatives, which will be screened for further evaluation. The FS Work Plan also provides an explanation of the screening process and further evaluation of the retained response action aalltteerrnnaattiivveess,, aass wweellll aass,, aa rreeccoommmmeennddaattiioonn ffoorr iimmpplleemmeenntatattiioonn ooff tthhee sseelleecctteedd rreessppoonnssee action alternative and associated conceptual design. 6.1 LIST OF POSSIBLE TECHNOLOGY TYPES It is important to note that soil, groundwater, and sediment at the Site are being considered as separate operable units. As such, a technology evaluation is provided for ecaacchh mmeeddiiaa ssoo tthhaatt mmeeddiaia--ssppeecciiffiicc tteecchhnnoollooggiieess ccaann bbee ccoommbbiinneedd iinnttoo rreessppoonnssee aaccttiioonn alternatives for each media. General response actions have been identified for the Site based on the information and data provided in this RI. The general response actions, response technology type, and associated process options are presented in Table 6-1 for soil, Table 6-2 for groundwater, and Table 6-3 fbr sediment along with a brief description of the process option and a screening comment. In their guidance, EPA states "During this screening step, process oppttiioons and ennttirree tteecchhnnoollooggy ttyyppes are elliimmiinated ffrroomm furtheerr coonnssiiddeerraattiioon on tthhee bbaassiiss ooff tteecchhnniiccaall iimmpplleemmenetnatbaibliilittyy"",, ((EEPPAA,,11998888).). TThhee ggeenneerraall rreessppoonnssee aaccttiioonn!/tteecchhnnoollooggyy Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnorssuurraannccee DDooccuummeenntt"ssol6-1 22116622..00115577 33MM_EENNVV_0000000033223333 3M MN01483158 pon ant proces options tat ave bee ein as the Lit of ove Thlogy types and process options that have been retained as the List of Possible Technology TTyyppeess ffrroomm tthhiiss iinniittiiaall ssccrreeeenniinngg aarree ssuummmmarariizzeedd bbeellooww:: LLIISSTT OOFF PPOOSSSSIIBBLLEE TTEECCHHNNOOLLOOGGYY TTYYPPEESS +I eMmonExTcrvaaion SSooiill Removal - Excavation Treatment - Thermal . TOI a ape Incineration Disposal - Landfill ~-- ENExixesiwsttiilnnaggndllfaainnldldffiillll a pl c yAe * CCoonntatinamiennmt--eCCnaatpp - Soil/clay cap - Engineered multilayer cap Zh an Institutional and Site Controls - Access restrictions - Deed restrictions - Fencing No action PRGroundwater + Colleton Gans nny Collection - Groundwater recovery tory Recovery wells + Distoes- One Discharge - On-site Dn Containment Cap Ser - Soil/clay cap EA - Engineered multilayer cap + TamEoe Treatment - Physical Taton - Activated carbon - Ion exchange resin pl ite - Reverse osmosis I- Air stripping + pa spati Goel Institutional and Site Controls peae - Deed restrictions - Fencing v0 - Monitoring No acti on Z:\FOLDERS.0-9\3rn-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDr ooccuummey ennttss6-2 22116622..00115588 33MM_EENNVV_0000000033223344 morass 3M MN01483159 Sediment Sediment = = RRTeemmrooevvaaall t---EEmPxhxceycasavnivacattatilioonn/DDrreeddggiinngg T-~- reaDDStuemerwwfeaanatctteeer-riwiPnanhgtgyesridciavlersion - Surface water diversion = TT=rereaaImtnmceiennntetr-a-tTTihohenerrmmaall Incineration = DD=iissNppoeosswaall l--anLLdaafnnidldflifillll ~- - ExNEixesiwtstiilnnaggndllfaainnldldffiillll = C=CooCnnlttaeaiiannnmmesenentdti-meIInnntSS,iittsuuanCCd,aappgravel, geotexile, or liner Clean sediment, sand~ gravel~ geotextile~ or liner = II~nnssttiiDttueutetiidoonnraaellstaarnniddctiSSoiinttese CCoonnttrroollss -- AAcccceessss rreessttrriiccttiioonnss ~- - Fencing Deed restrictions Fencing + NNooaaccitioonn UUppoonn aapppprroovvaall ooff tthhee RRII RReeppoorrtt aanndd FFSS WWoorrkk PPllaann bbyy MMPPCCAA,, tthheessee tteecchhnnoollooggyy ttyyppeess aanndd aassssoocciiaatteedd pprroocceessss ooppttiioonnss wwiillll bbee aasssseemmbblleedd iinnttoo. rreessppoonnssee aaccttiioonn aalltteermnaattiivveess ffoorr ssccrreeeenniinngg aanndd ffuurrtthheerr eevvaalluuaattiioonn.. 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Zs 3% i3 E2 221g2)] 82 3|: | 855% | 2s3z 23 i dla] 84133 28 < i 3z 3 i gE "2 HE 82% t| 3 ili 8 S 1 |. ole] a = ii i i CCoonfnifddeenntitiaall ~- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00116644 33MM_EENNVV_0000000033224400 Suumoressies 3M MN01483165 2: g z FE | Ei] | E|EE E 22 sEll:):i EEl5 z 25 3 HEHEREIEE & Z| 2 2 | 22 x 2 | z2 g 5gil l::: elf HIREEH 53 [Ez| 22s |e 2 2 2 5 587 |2:8 25 325 (|3103| 2g2ee2 [fi2e5d a7 BERHEHTREE EEE HE I els d] l ls|2|&sE|2 25 2- | = 22 sH BL|E&A ]| E=Fo iis Bi = &M& : : 2] 7 |f 3 32.0 |f IE THE S| #3 |: CCoonfnifddeennttiiaall ~- 33MM IInnssuurraannccee DDooccuummeennttss 22116622..00116655 2 i i i if i i 4i 2 33MM_EENNVV_0000000033224411 Suumoressies 3M MN01483166 77.. RREEFFEERREENNCCEESS WESTON~ 2006. FluorochemJcal (FC) Dam Assessment Report.for the 3M Company Cottage Grove, Minnesota Faci#ty. Prepared by Weston Solutions, Inc. for the 3M Company~ April 2006. USEPA~ 1988. Guidartce for Condz~cting Remedial htvestigations ctnd Feasibility Studies ttltder CERCLA. Interim Final, October 1988. FE Z:\FOLDERS.0-9\3m-cottage grove\Phase 2 FC Data Assessment Report\Final Phase 2 R=.port doc CCoonfnifddeentnitaiall-- 33MM IInnssuurraannccee DDooccuummeennttss7-1 22116622..00116666 33MM_EENNVV_0000000033224422 3M MN01483167