Final May 2011 Model Run for Spokane River DO TMDL Equivalency

May 31st, 2011

Final May 2011 Equivalency Model Run for DO TMDL Compliance

This memo reflects Ecology and EPA evaluation of modeling performed by LimnoTech on behalf of the Spokane River Stewardship Partners (SRSP) to determine whether it is equivalent with dissolved oxygen impacts contemplated by the Spokane River DO TMDL, specifically Table 7.

Ecology and EPA conclude that “… these limits are, in fact, consistent with the assumptions and requirements of the wasteload allocation for the Washington point sources (specifically IEP and Spokane County), and will ensure compliance with Washington’s water quality standards for DO, when considered cumulatively with other actions taking place under the TMDL.”