Total Maximum Daily Loads

In September 2006, EPA approved DEQ’s mercury TMDL for the entire Willamette Basin. DEQ developed the TMDL to meet a mercury target in place at the time. Northwest Environmental Advocates filed a lawsuit in 2012, which argued the validity of the mercury  TMDL and EPA’s approval of the TMDL. In April 2017, the US District Court issued a ruling requiring EPA to revise the TMDL by April 2019, and allowing the 2006 TMDL to remain in effect until EPA issues or approves the revised TMDL. The court has since approved a DEQ and EPA extension request to Nov. 29, 2019.

 
DEQ and EPA are revising the TMDL to meet Oregon’s current water quality criterion for methylmercury, which is eight times more stringent than the target in effect in 2006. EPA approved Oregon’s revisions to its methylmercury fish tissue concentration criterion for the protection of human health in October 2011. The revised criterion changed the acceptable level from 0.3 mg/kg (milligram of methylmercury per kilogram of fish tissue) to a significantly more protective level of 0.040 mg/kg.
 

Current actions

The public comment period for the revised Willamette Basin Mercury TMDL closed on Sept. 6, 2019 following a three-day extension request from nine organizations. DEQ will review public comments through October and make any needed revisions to the TMDL. DEQ expects to issue the TMDL mid-November with an EPA decision by the end of November.
 
On July 3, 2019, DEQ released a draft revised mercury Total Maximum Daily Load and Water Quality Management Plan for the Willamette Basin. Public comments were due by 5 p.m. on Sept. 6, 2019, following a three-day extension request by nine organizations. DEQ will review public comments through October and make any needed revisions to the TMDL.
 
DEQ held two public hearings on the same day in two locations:
Portland-area public hearing - Wednesday, Aug. 7, 2019
6 p.m. – 8 p.m.
DEQ Headquarters
3rd Floor Conference Room
700 NE Multnomah St. Portland, OR 97232
 
Eugene-area public hearing - Wednesday, Aug. 7, 2019
6 p.m. – 8 p.m.
DEQ Eugene Office
165 E. 7th Ave., Suite 100
Eugene, OR 97401
 

Public hearing documents

 

Contact

Willamette Basin Mercury TMDL advisory committee managers:
Andrea Matzke, 503-229-5350
Priscilla Woolverton, 541-687-7347
 
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Click for a larger map of the 303(d) listings for mercury in the Willamette Basin.

 

Mercury in Oregon Waters