Document ypw80R59Bryqp42Dy7jD0e4k4

Sia Opnions R ioS w W : 33MM EPanvviicroonnmmeenntatall,, Health Health snd and PPOO BBooxx 3333333311 Safe~ Operations St. Paul, Mix/55133-333 65t 778 6442 3M om July 26, 2004 MarkRys Mark Rys Nimes olution Control Age Minnesota Pollution Contro! Agency 520 Lafuyetc Road 520 Lafayette Road Saul, MN 551554196 St. Paul, MN 55155-4194 Re: Oakdale Dispos Sto Re: Oakdale Disposal Site Dear Mak: Dear Mark: Tank you fo meting with us to dics MPCA's Jue 7, 2008 ler requesting groundwater Thank you for meeting with us to discuss MPCA's June 7, 2004 letter requesting groundwater sampling fo peecroocan cid (PFOA) and perfluroctaesufonate (PFO) a the Oskile sampling for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonate (PFOS) at the Oakdale Dison Sie A we duaued during or Jy 8 mecin, SM plans 0 conduct he sampling 3 Disposal Site. As we discussed during our July 8 meeting, 3M plans to conduct the sampling in a Phased spprse savin is Ast 8 summarized below. phased approach starting this August as summarized below. As you Know, MPCA bal squested hat 3M collet samples st ur Woy se snd analyze As you know, MPCA has also requested that 3M collect samples at our Woodbury site and analyze {he sample Go PFOTFOS. Thagree uponspprosch at Woodbury to fs olects the samples for PFOA/PFOS. The agreed upon approach at Woodbury is to first collect a Corie Tent sample om the groundwate p-au ystems esi. The sample recs combined effluent sample from the groundwater pump-out system at the site. The sample results he eve ade sed or a cxpandd sampprom wilbe dtcrmined bed an will be reviewed and the need for an expanded sampling program will be determined based on {hes els. We believe ths phased sre aposeh shoud so be implemen i he these results. We believe this phased screening approach should also be implemented at the aie sie Oakdale site. "Th Ouse ste moniring rests demonstrate tht the pump-out ysis has efetvely capes The Oakdate site monitoring results demonstrate that the pump-out system has effectively captured nd eda he Enof Sraminaed founder at te. The cssing pump-out vel and reduced the extent of contaminated groundwater at the site. The existing pump-out wells Toman wate 4nd VOC rm aoe he ior pol rcs and lumaily produc combined remove water and VOCs from across the historic disposal area and ultimately produce a combined hort tor drt oo amar ewer. 1 FC isos accumehde Oaisl si, it. effluent that is discharged to the sanitary sewer. ]fFC disposal occurred at the Oakdale site, it olde expected a nile wih he sms cts where VOCced disposal aecurd and tf would be expected to coincide with the same areas where VOC-related disposal occurred and it is propio se ot he onal pesencof FEOAIPFOS inthe combined een of he appropriate to screen for the potential presence of PFOA/PFOS in the combined effluent of the pou sys, We unbtand t MPAs main concen i ri to podten ehrges pump-out system. We understand that MPCA's main concern is related to potential discharges Tho mee isomer sytem. I the ent ess wart fre assent, he est into the municipal wastewater system. If the et~uent results warrant further assessment, the next he ofsmplig wkd nude collin Erundwate samplesFo combination ofur ot phase of sampling would include collecting groundwater samples from a combination of pump out nd monitoring wel in hore disposal area and monitoring wells in historic disposal areas. Sample colton wil be performed consistent with meth preouly sobre by 3M fo the Sample collection will be performed consistent with methods previously submitted by 3M to the MPCA ithe Cog Grove D1 Wosk lan We understand tht 1 his me MFCA dos rt ani MPCA in the Cottage Grove D-1 Work Plan. We understand that at this time MPCA does not want Lost sams. We wil natty you aye shed of the scheduled sample collection ae. If ou to split samples. We will notify you 5 days ahead of the scheduled sample collection date. If you SHaivncaey,ston, pls contact me at651-775-5544 have any questions, please contact me at 651-778-5344. TSocdidoiEnfvironmental E7 ngineer Senior Environmental Engineer ate, CCec.. DDaann FFetetetrt,er, BBaarmr ps BExahiiblit 1958 State of Minnesota v. 3M Co., Court File No. 27-CV-10-28862 MA0034B14 3MA00348164 11995588..00000011