Document ErkywkKLqmVYbemyZ4z5J8mx

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 273? Certified Mail June 14, 2005 2095JUM2 i AHil : 3 j 9 - O ^or-O o37 3 Document Processing Center EPA East - Room 6428 Attn: Section 8(e) Office of Pollution Prevention and Toxics U.S. Environmental Protection Agency 1200 Pensylvania Avenue, NW. Washington, D.C. 20460-0001 NO CBI ? exnr Re: TSCA Section 8(e) Supplemental Notice: Sulfonate-based and Carboxylic-based Fluorochemicals, Docket Nos. 8EHQ-1180-374; 8EHQ-0381-0394: 8EHO-0598-373 Dear Sirs: 3M is submitting this letter to supplement its previous submissions on sulfonyl and carboxylicbased fluorochemicals and specifically its February 9,2005 submission with analytical data for water samples. 3M has recently received summaries of analytical data from the State of Minnesota Department of Health (MDH) for water samples taken from private wells in the communities of Oakdale and Lake Elmo, Minnesota. The sampling and analysis of these wells was performed by the Minnesota Department of Health (MDH). 3M is providing a brief summary of the information in this letter; however, it is our understanding that the actual laboratory reports would be available from MDH upon request. Each sample was analyzed for perfluorooctane sulfonate (PFOS) (C8F17SO3H) and perfluorooctanoic acid (PFOA) (C7F15COOH). The MDH Environmental Laboratory lists "Report Levels" in their reports to describe the analytical sensitivity of the test method employed. For the work addressed by this submittal, the "Report Levels" were 0.5 and 1.0 parts per billion (ppb) for PFOS and PFOA, respectively. PFOS was not detected in any of the seven Oakdale samples. PFOA was detected in one Oakdale sample but at a concentration below the "Report Level" of 1 ppb. Of the 141 Lake Elmo locations sampled in 2005, 114 were reported as "non detects" or had results below the previously referenced "Report Levels". There were 15 locations where results were above "Report Levels" but below health-based criteria and 12 samples with results at or just above State of Minnesota health-based criteria. As 3M understands the situation, MDH, in conjunction 89050000450 0 50000 with the Minnesota pollution Control Agency, is arranging for installation of carbon treatment on these wells and has supplied bottled water in the meantime. As discussed in our February 9, 2005 submission, MDH, the primary agency in Minnesota for purposes of the federal Safe Drinking Water Act, 42 U.S.C. 300f et seq., has established Health-Based Values (HBVs) of 1 ppb and 7 ppb for PFOS and PFOA respectively. In the case where both PFOS and PFOA are present, MDH also has recently begun applying an additive model that generates a Hazard Index (HI) by adding together the ratios of the concentration of each substance to its HBV. Using this approach, MDH considers an HI of 1 as analogous to the HBV for an individual substance.1 In communicating these water data to the public, MDH has explained that HBVs represent levels considered safe for exposure, even over a lifetime.2 As to the Lake Elmo data, even where exposure may have occurred above health-based criteria, given that such criteria include a factor to account for other exposures and additional safety factors, it is believed that an adequate margin of safety exists.3 In view of the MDH's communication --which is supported by our own review of the extensive data base - 3M does not believe that these data meet the TSCA Section 8(e) "substantial risk" reporting threshold. Nevertheless, 3M has decided to report this information, recognizing its importance to the ongoing work by U.S. EPA to assess fluorochemical exposure pathways and potential risks. If you have any questions, please do not hesitate to contact Michael A. Santoro at (651) 7336374. Sincerely, -fiLV Katherine D. Reed, PhD Staff Vice President Environmental Technology and Safety Services DCY766620.1 MDH "Models for Assessing Health Risks o f Chemical Mixtures", available at www.health.state.mn.us. MDH Environmental Health Information Periluorochemicals and Health, available at www.health.state.mn.us. MDH "Lake Elmo Groundwater Investigation Overview" (Apr. 26, 2005), available at www.health.state.mn.us.