Document YrpGpKVBGweaRMdxLXvpk0Bwk

OEPA/DuPont Off-site Water Sampling Review ^ ;:.i .. i: ' - s -" '' -' " ' :.: i;: ' ,'*. ..- ' ... October 22, 2002 AR226-2596 ASUQ19867 m H D 111 - H 'll' ' 11 ;il i Water Sampling Topics For Today I Ohio 2-M ile Radius Sampling Results l Groundwater Modeling Update **Little Hocking W.A. Investigation Results i Groundwater Results/Soil Analysis Status ^P ublic Water System Sampling Update ^Status o f Water Sampling Work Under , 1 WVDEP Consent Order o H <0 i E ID 630300 Ohio 2-Mile Residential Sampling Results DuPont Washington Works Aerial View-Looking North ASH019870 EID630302 Ohio 0-2 Mile Water Sampling Scope Summary ^O ver 1200 homes surveyed/interviewed ^ O ver 130 residential drinking water & groundwater samples collected HOw u> A SH 019871 ASH019872 EID630304 EID630305 Ohio 2-Mile Sampling ^Observations: All results significantly below 150 ug/L screening level for drinking water Definite trend toward lower concentrations in the 1 to 2 mile radius sampling area (vs 0 to 1 mile) Highest drinking water result: 6.5 ug.L (BoardJG, close to 1 mile boundary) Highest drinking water result near 2-mile boundary: 2.59 ug/L (KnottsC, west of Little Hocking) 1.81 ug/L (SmithDD, north of Porterfield) A SH 019874 ASH019875 EID630307 Groundwater Modeling ^Project Objectives: Evaluate if a groundwater flow pathway exists between DuPont site and Little Hocking W ell Field under current flow/pumping conditions. Evaluate other possible flow/pumping conditions g es o H<0 E ID 630308 Pumping Rates, February 2, 2002 (gpm) Site DuPont (exc. Gallery) GE Little Hocking Lubeck Belpre Total (gpm) 6804 2100 490 462 70 E D 630309 Groundwater Flow-Current Pumping Conditions \\ u- Dm w OL) ITS ASHQ19878 No DuPont Pumping sa o 5>3; (0 E ID 630311 Little Hocking Water Association Well Field Investigation 'iilTlsk," - : LHWA Investigation ^ O b jectives: Determine reason for elevated C-8 concentrations in TW-4 Understand general distribution o f C-8 in soil and groundwater E D 630314 ? o H V) CO co N A SH 019883 MO o\ Ul' Water Data Summary (in ug/L) Production Well C-8 Concentrations: Well 1 (1.7-3.6) Well 3 (.42-.96) Well 2 (2.0-4.3) Well 5 (5.7-8.1) Test Wells: TW-1 (.8-2.2) TW-4 (12.3-37.1) TW-9 (.1-.3) TW-10 (1.1-1.9) Probe Investigation: WHO m <J3 Shallow GW . Mid aq. GW ND, 6.2,34.6,50.8,78 1.32 Deep aq. GW .166 (next to TW -4) A SH 019884 Preliminary Observations 2 No results higher than 150 ug/L screening level Production-finished water consistently around 2 ug/L 2*> Higher C-8 concentrations in shallow groundwater where fine grained aquifer matrix (lie., clays/silts) present Steep downward trend in aquifer C-8 concentrations with depth 2*> Higher concentrations observed in TW-4 anomalous compared to overall data set A SH 019885 ASH0198B6 W H u II m Ho O 00 ASH0198B7 A A' A SH 019888 Hma U)a $ iECEWD: SCREENED tHTERVAl Hi TEST ELL O ? WUJOUCTIOH' WELL C W N 0 WATER SAMPLE CDCATtQM IN CEOPROBE OR ROTOSGMC BCRtNG fi C~V CONCfNTRATfON (uqA.) GROUNDWATER ELEVATION * SO t SAMPLE LOCA1 ON H o riz o n ta l S c a le ; 1 " 0* V e rtic a l S c a le : 1 " - 1 0 ' DRAFT ^ C o r p o r a te F te m o tfa tie a Grc-oo *,>:* <s 'vj-rs C R O SS -SE C T IO N A -A ' Ultfe Mocking W at' Assoo'otton tittle Hacking, OHio - f '-^1 r- . r- B 0 2 0 --| VCLL#1 m u ft WEUP OHIO RfVER \ W H Dm u LEGEND: SCREENED INTERVAL O f TEST NELL OR PRODUCTION WELL N o rtro n ln l S c a le 6 0 ' V o rlie e t S cot: 1* i f f 6886T0HSV 1 ESTIMATED SCREENED INTERVAL t , IN TEST WELL OR PRODUCTION WELL [ GROUND WATER S A U P tt LOCATION | S i IN G tO P flO e t OR ROTOSOWC BORING C1 '!*) CH8 CONCENTRATION ( g /t) GROUNDWATER ELEVATION DRAFT lit- C^p***'* Mt*= tsxZ+ & Group r CROSS--SECTION 8 -B * LIU! Hockinj Watr AoKiCietJon Ultl HoekJny. Ohw ITT c -East WELL # 2 a West- ASH01989Q 3 Ho mU) S C R E D A INTERVAL ttf TEST W il OR PSCDUCION U CSTIU AID SCRFTMfC INCURVAI. IN TEST W XL OR PfDDUClBOK V C lt s> GROUND WATER SAMPLE LOCATION IN cto R tce e OR ROTDSONC SORNG ~ y -~ C -5 CCKCENTRAHON (u g ^ t) g roundw ater elevatio n K w ra n ia i S sc s* 80* Verfeol S e d e T* * TU' DRAFT sii#- ^ CROSS--SECTIONC-C CsVparswft*wV'-lX*trS:.5.s. isfOMS UltoMLoRcUSmsHssclotnog.AOwWaoeiHCen C-.-*.*.,,?.!t vv ** h.-.---f[-i----.--| wp*--(---- I I Ohio River Public Water Systems & ....:!'I!5-.S,. . to Kiver Surface Water Sampling Summary o H<0 C<O0 E ID 630323 A SH 019892 ED630324 Ohio River PWS Summary (in ug/L) 2* +5 3*1+3 3 0 2V -3 ! -18 W -30 2 -40 -42 2* -45 tv _48 s* -50 Parkersburg Bel Pre LHWA Lubbeck Tuppers Pl. Ravenswood Mason Cty Letart LF Racine L&D VilLof Racine Vill of Syracuse ND 1-.3 .8-8.2 .2-1.0 .2-.7 ND NQ-.l .518 ND ND-.41 EXD630325 Surface Water Summary (inug/L) Transect 1 ^ Transect 2 Transect 3 ** Transect 4 ** Transect 5 Transect 6 ** Transect 7 Transect 8 3* Trasnect 9 *> Transect 10 > Transect 11/12 25+ 12+ 3+ upsite midsite -1/2 -1.5 -3.0 -10 -18 -42(Letart) ND (2 samp) ND (2 samp) ND (2 samp) ND (9 samp) ND (10 samp) ND (9 samp) .09-.13 (2 samp) .9-1.1 (2 samp) .29 (2 samp) .23 (2 samp) .1 (4 samp) ASHQ19894 WVDEP Multi-Media Consent Order- Water Sampling Update MMCO Water Sampling Update w Have completed the following: Off-sites 1 mile and 2 mile radius sampling Monthly sites sw/gw sampling (4 rounds), now qtrly Monthly sites putfall sampling PWS System sampling (now qtrly at 3 facilities) Ohio River sw sampling Sites plume delineation field work (28 new wells installed, gw/sw sampling full event just completed) z* To complete: Water sampling final report Groundwater modeling final report A SH 019896 Intentionally Blank i ix t o H<0 a ->4 E ID 630329 N ;'f.: A 5H 019898 1D630330 Little Hocking Water Association Well Field a o H to CO to to E ID 630331 LHWA-Groundwater Travel Times ( in days) sW Oi W ASH019900