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NWEA Challenges Oregon’s Temperature Standard & Willamette Basin Mercury TMDL

October 4, 2012

Co-authored by Elizabeth Howard and Mary Anne Nash.

Late last week, and a mere 6 days after filing a 60 day notice, the Northwest Environmental Advocates (NWEA) filed suit challenging the United States Environmental Protection Agency’s (EPA) approval of numerous Total Maximum Daily Loads adopted by the State of Oregon.   A Total Maximum Daily Load, or TMDL, is an enforceable plan developed by DEQ that calculates the maximum amount of a pollutant that a water body can receive without exceeding water quality standards and applies those “loads” to point and non-point sources within certain water bodies.

The NWEA lawsuit challenges EPA’s actions in approving Oregon TMDLs, but is really a challenge to Oregon’s temperature water quality standards.  Oregon’s temperature standard is set to achieve certain fish-based temperature criteria, but accepts the fact that natural conditions may not allow certain stream reaches to achieve these criteria.  NWEA challenges every TMDL where DEQ determined that the natural conditions in the relevant water bodies should be the limit of the water quality standard.  NWEA argues that DEQ’s analysis to determine natural conditions was inadequate and that the temperature standard should not necessarily account for natural conditions.

NWEA’s suit also challenges the EPA’s failure to examine whether TMDLs were developed to address other water quality standards in the relevant water bodies.  NWEA asserts that EPA acted arbitrarily and capriciously in approving Oregon’s TMDLs without including an adequate margin of safety to address the difference between Oregon’s estimate of natural conditions and the biologically-based criteria previously approved by EPA.

NWEA’s arguments build on a February 2012 decision in a case it filed in 2005.  There, Oregon federal district judge Acosta ruled that EPA wrongfully approved the recognition of natural conditions in Oregon’s water quality standards.  The Court also found that EPA was required to review Oregon’s nonpoint source programs.

That case is still pending, waiting for a determination as to how the EPA should respond to the decision.  The State of Oregon is a party to the case, as is the Northwest Pulp and Paper Association, an organization representing timber and paper interests.  No party has formally announced whether it will appeal the decision once a final judgment is entered.

The last part of the new NWEA suit is a challenge to the mercury TMDL for the Willamette Basin.  The suit claims the TMDL is incomplete and fails to adhere to the state’s water quality standard, and in particular does not protect beneficial uses such as wildlife, fish and human safety.  Of particular note is NWEA’s claim that the mercury TMDL does not reflect the recent Oregon determination that Native Americans consume 175 grams per day of fish.

If you have questions, please contact me at or Elizabeth Howard at

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