Publication Summary

The Walla Walla and Touchet rivers were listed under Section 303(d) of the federal Clean Water Act for non-attainment of criteria for recreational-contact, fecal coliform (FC) bacteria. This report is the technical portion of a Total Maximum Daily Load (water cleanup plan) evaluation for FC bacteria in the Walla Walla River basin, and forms the basis to set FC load reductions from nonpoint (diffuse) and point (discrete) sources.

Reaches of the Walla Walla River and its tributaries were given FC load reduction targets. Wastewater treatment plants in Dayton, College Place, and Walla Walla, as well as potential municipal stormwater permit holders, were given FC wasteload allocations.

The Walla Walla and Touchet rivers have been listed under Section 303(d) of the federal Clean Water Act for non-attainment of Washington State water quality criteria for recreational contact fecal coliform bacteria. The listings are based on sampling conducted by the Washington State Department of Ecology (Ecology) since 1991.

The U.S. Environmental Protection Agency requires states to set priorities for cleaning up 303(d)-listed waters and to establish a Total Maximum Daily Load (TMDL) for each. A TMDL is an analysis of how much of a pollutant load a waterbody can assimilate without violating water quality standards.

This TMDL report describes (1) the technical data evaluation for fecal coliform bacteria in the Walla Walla River basin, and (2) the basis for allocating fecal coliform loads to nonpoint (diffuse) and point (discrete) sources. Ecology conducted the study for 13 months, June 2002 through June 2003.

Reaches of the following waterbodies were given fecal coliform load reduction targets: the Walla Walla and Touchet rivers; the west branch of the Little Walla Walla River; and Dry, Pine, Mud, Mill, Garrison, Yellowhawk, Russell, and Cottonwood creeks.

The wastewater treatment plants for the cities of Dayton, College Place, and Walla Walla, as well as potential Phase 2 municipal stormwater permittees, were given fecal coliform wasteload allocations.

Link to EIM data for User Study ID JJOY0003