Publication Summary

This is the study plan for the Palouse River Dissolved Oxygen and pH Total Maximum Daily Load - Water Quality Study Design.

Section 303(d) of the federal Clean Water Act requires the state of Washington to prepare a list of all surface waters in the state for which beneficial uses of the water are impaired by pollutants. Waterbodies placed on the 303(d) list require the preparation of a Total Maximum Daily Load (TMDL) study to identify and quantify sources of the impairments and to recommend implementation strategies for reducing point and nonpoint source loads.

The Palouse River and Cow and Rebel Flat Creeks have been listed by the state of Washington for non-attainment of Washington State dissolved oxygen and pH criteria. Additional 303(d) listings exist within the Palouse River watershed for temperature, fecal coliform bacteria, and ammonia.

EPA requires states to set priorities for cleaning up 303(d) listed waters and to establish a TMDL for each. A TMDL entails an analysis of how much of a pollutant load a waterbody can assimilate without violating water quality standards. The Palouse River TMDL study will address the 303(d) listings within the watershed with three separate Quality Assurance Project Plans: one for bacteria, one for temperature, and one for dissolved oxygen and pH.

This Quality Assurance Project Plan describes the technical study that will monitor dissolved oxygen and pH in the Palouse River watershed, and will form the basis for a proposal to allocate contaminant wasteloads to sources. The study will be conducted by the Department of Ecology′s Environmental Assessment Program.

Link to EIM data for User Study ID JICA0001