Document mBDqNqZkV7Y0p6NyyYXBvXNMg

April 24, 2017 Colleen Flaherty Health and Ecological Criteria Division Mail Code 4304T U S. Environmental Protection Agency 1200 Pennsylvania Ave., N.W. Washington, D C. 20460 ATTN: Docket ID No. EPA-HQ-OW-2016-0353 Submitted electronically via regulations.gov and to flaherty.colleen@epa.gov In Re: Comments of the National Mining Association on the U.S. Environmental Protection Agency's Draft Field-Based Methods for Developing Aquatic Life Criteria for Specific Conductivity Dear Ms. Flaherty, Attached please find the comments of the National Mining Association (NMA) on the U.S. Environmental Protection Agency's draft document, Field-Based Methods for Developing Aquatic Life Criteria for Specific Conductivity. 81 Fed. Reg. 94379 (Dec. 23, 2016). NMA is a national trade association that includes: the producers of most of the nation's coal, metals, industrial and agricultural minerals; the manufacturers of mining and mineral processing machinery, equipment and supplies; and the engineering and consulting firms, financial institutions and other firms serving the mining industry. NMA appreciates this opportunity to comment on EPA's draft conductivity methodology. NMA's comments identify several significant flaws with EPA's draft methodology that render it inappropriate for use in the derivation of numeric aquatic life criteria. Most notably, the comments explain how the proposed methodology does not produce criteria protective of 95% of aquatic species, fundamentally misinterprets EPA's 1985 Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses, and fails to account for data that provides substantial evidence for the fact that conductivity is not likely the causative factor for the presence or absence of genera. NMA's comments also note concerns regarding the fact that EPA failed to conduct a new causality analysis, despite the fact that such an analysis is critically important where a field-based method using data subject to a potentially high degree of confounding is proposed. Sierra Club v. EPA 18cv3472 NDCA Tier 2 1 ED 002061 00106923-00001 These weaknesses in EPA's proposed approach preclude its adoption. As such, NMA requests that EPA withdraw the proposed methodology in its entirety. Please contact me at aaspatore@nma.org or (202) 463-2646 with any questions. Sincerely, J/fY'.&H Amanda E. Aspatore Vice President, Water Law & Policy National Mining Association Enclosure Sierra Club v. EPA 18cv3472 NDCA Tier 2 2 ED 002061 00106923-00002