Document NGMrw0DGw2LVpLEGGYxnDM1pb

3M Katherine E. Reed, Ph.D. Staff Vice President 3M Environmental, Health and Safety Operations 900 Bush Avenue, Building 42-2E-26 PO Box 33331 St. Paul, MN 55133-3331 651 778 4331 g ens. Certified Mail April 14, 2006 0 4 -0 6 - O039U- n[ r y'U AR226-3643Fm m r i H 2t SI* CcDn X~o "4 T?m ro 4 Document Processing Center EPA East - Room 6428 Attn: Section 8(e) Office of Pollution Prevention and Toxics US EPA 3r3r o< m Cv 9? CD CO 1200 Pennsylvania Avenue NW Washington DC 20460-0001 89060000299 89060000299 Re: TSCA 8(e) Substantial Risk Notice: Sulfonate-based and Carboxylic-based Fluorochemicals, Docket Nos. 8EHQ-1180-374; 8EHQ-0381-0394; 8EHQ-0598-373 - Results from Analysis of Groundwater in the vicinity of former Oakdale Disposal Site To whom it may concern: 3M is submitting this notice to supplement its previous submissions on sulfonyl and carboxylicbased fluorochemicals. 3M has recently received the enclosed analytical report (3M Environmental Laboratory Report No. 06-0151) for groundwater samples collected in the vicinity of the former Oakdale Disposal Site (Site) in Oakdale, MN. From the late 1940's until 1960, a variety of industrial and municipal wastes were disposed of at a property know as the Abresch site in Oakdale, MN. This location is also known as the Oakdale Disposal Site and underwent an extensive site remediation/cleanup in 1983-84. In 1985, a pump out system was installed to remove and contain solvent-impacted shallow groundwater at the Site. This system has been in continuous operation since installation. 3M has been leading a study, with involvement from the Minnesota Pollution Control Agency (MPCA) and Minnesota Department of Health (MDH), to characterize the presence of fluorochemicals at the Site. In an early phase of this assessment, existing on-site and near site monitoring and pump-out wells were monitored for fluorochemicals. Results from this work are provided in Exygen Study No. P0001400, Interim Report #1, enclosed. A map depicting the locations of these wells is also enclosed as Figure 1. The results from this early work were used as a basis for locating nine additional monitoring wells. Four of these monitoring points are on site and five are in close proximity to the Site. The location of these wells is provided on Figure 2, enclosed. Results from the first round of sampling for these wells are contained in the aforementioned 3M Environmental Laboratory Report (No. 06-0151). The new wells were constructed to sample from four different geological strata: alluvium, Platteville limestone, St. Peter sandstone and the Prairie du Chien group. These are depicted on Figure 3 for the Site. Results for four of the five offsite wells are below the limit of quantitation OOOOOl (0.025 ng/mL) for all analytes. Levels in the fifth offsite well are significantly less than 1 ng/mL (ppb) for each analyte. While 3M does not believe that any of these data taken alone or cumulatively meet the "substantial risk" reporting threshold, we nevertheless recognize the ongoing work by U.S. EPA to assess fluorochemical exposure pathways. Therefore, we are placing these results in the 8(e) docket as a supplement to previous submissions. If you have any questions, please do not hesitate to contact Gary Hohenstein at (651)778-5150. Sincerely, Katherine E. Reed Staff Vice President Environmental, Health and Safety Operations Enclosures 000002