Water Quality photo identifier

Water Quality Program

Straight to Implementation

Straight to implementation (STI) is a a tool Ecology uses to clean up a watershed without having to develop a total maximum daily load (TMDL). While TMDLs are very useful to identify pollutant sources and set targets for pollutant reductions, there are times when we already know what the pollutant sources are and what we need to do about them, so a TMDL is not necessary. This happens most often in watersheds with a small set of similar land uses. In these situations, Ecology may choose to work directly with landowners and other partners in the watershed to implement management practices that will eliminate the pollution problem.

How does it work?

Ecology staff assess polluted water bodies and make a preliminary identification of the point and nonpoint sources of pollution. They then decide whether a STI approach can be used or whether a TMDL is needed. STI cannot be used in watersheds in which there are wastewater treatment plants or other point source dischargers that must be given more stringent effluent limits in order for the water to meet water quality standards.

Mouth of the Wenatchee River as it enters the Columbia River.  Photo courtesy of Bryan Neet, Dept. of Ecology.

If Ecology decides to use STI, staff must then determine which BMPs will address the pollutants. It generally takes a suite of BMPs to fully address the pollution. For instance, in a watershed impaired by nutrients, low dissolved oxygen, and temperature, the suite of BMPs could include installation of a riparian buffer stocked with native shrubs and trees, livestock exclusion fencing, and an off-stream watering facility. In some cases, however, a single BMP may be sufficient. An example of this situation would be in a watershed impaired solely by failing septic systems. In that case, the single BMP might be to replace the failing systems and put them on a regular maintenance schedule.

In all cases, Ecology’s goal is to eliminate pollution from all of the identified sources. To do this, staff work with landowners and various groups in the STI project area. They provide information about the pollution problems and the identified solutions, provide technical assistance, and may assist with identifying sources of financial assistance.

Ecology is currently implementing several STI projects, and we have seen significant improvement in water quality in the STI watersheds.


Water Quality Success Story: Straight to Implementation: Cleaner Water Faster

Last updated June 2013