Publication Summary

This implementation plan details how and when pollution reductions will be achieved to meet water quality standards in the Johnson Creek watershed.

Violations of standards for fecal coliform and dissolved oxygen were documented in 1998 through extensive sampling of Johnson Creek and key tributaries. In June 2000, the Washington Department of Ecology (Ecology) established fecal coliform pollution limits for the Johnson Creek watershed through adoption of its "total maximum daily load" (TMDL) analysis.

As required under an agreement between Ecology and the U.S. Environmental Protection Agency, the following plan details how implementation will occur to achieve pollution reductions specified in the Johnson Creek TMDL.

This document provides a framework for implementing wasteload allocations and load allocations established in the Johnson Creek TMDL. The responsibilities of each of the parties, and the means of tracking results, are also established.

The pollution reduction targets of the Johnson Creek TMDL are based on bacterial criteria of the Washington State Water Quality Standards. There are two criteria for bacteria. The first criterion sets a maximum for the geometric mean criteria. The second criterion sets a maximum density of bacteria for the 90th percentile. Experience has shown that when correcting nonpoint pollution sources, both the geometric mean and the 90th percentile will drop at similar rates. For this study, the 90th percentile criterion was the most stringent criterion. As a result, geometric means targets are below the criterion of 100 cfu/100 ml established in the Water Quality Standards. It is against the target geometric mean that tracking will primarily take place.

The implementation of the load allocation is based on the assumption that existing rules, regulations, and programs, if fully implemented, will achieve our goals for the Johnson Creek watershed. Adaptive management methods will be used to quickly identify whether additional effort or focus from existing programs is needed. If adaptive management demonstrates that existing programs are not adequate, new programs will be developed.

The primary means of ensuring compliance is a quarterly comparison of water quality monitoring data with established targets. Also tracked will be implementation milestones to be achieved by a variety of organizations. Several agencies have begun working to meet the objectives of the Johnson Creek TMDL. Already water quality criteria are being met in Johnson Creek and its tributaries.