Puyallup River basin TMDLs

A TMDL was developed that established waste load allocations for point sources for biological oxygen demand (BOD), ammonia, and chlorine in the Puyallup River basin. Dischargers permitted through the National Pollutant Discharge Elimination System (NPDES) include ten municipalities, four industrial discharges, and four fish hatcheries. Background and nonpoint source loads were also assessed. In addition to considering existing discharges and nonpoint loads, the potential impact of future dischargers was examined.

TMDL was completed and the final report approved by the EPA in November 1994. Later, new information became available that raised questions regarding the ability of the river capacity to assimilate additional 5-day Biological Oxygen Demand (BOD5) and ammonia loads. There is a moratorium on using the TMDL growth reserve until new data shows that accessing the reserve won’t result in a water quality violation.

The Puyallup River and several tributaries have fecal coliform bacteria levels higher than Washington’s allowed standards for freshwater streams. These typically harmless bacteria tend to exist along with disease-causing bacteria and viruses (i.e., pathogens), so they indicate the potential for pathogens in the water.

We worked with local governments, resident groups, and permit holders to develop actions needed to reduce fecal coliform in the Puyallup River watershed. The resulting water quality improvement report contains the results of the TMDL study and an implementation plan. The plan identifies implementation activities for various partners, many of which are already underway. EPA approved the final TMDL report in September 2011.

The Lower White River has a problem of high pH.  We found that excessive nutrients (phosphorus) cause high pH in the river. Several years of monitoring in the White River show pH regularly exceeds the healthy range for fish and aquatic species. These additional nutrients increase underwater plant growth which changes the oxygen and carbon dioxide cycles increasing pH.

We wrote a collaborative TMDL with the Muckleshoot Indian Tribe and the EPA with a goal to limit nutrients and to describe best management practices needed to reduce phosphorus pollution. The final TMDL report was approved by EPA in January 2023 and the implementation plan details actions needed to help reduce pH and phosphorus pollution.

The plan identified that the excess nutrients come from both point sources and nonpoint sources. The wastewater treatment plants at the cities of Buckley and Enumclaw are a primary source of the phosphorus pollution. The cleanup plan also addresses phosphorus from several other permitted sources: sand and gravel facilities, and stormwater from municipal, construction, and industrial facilities. For nonpoint sources, nutrient control focuses on promoting BMPs like proper manure storage and fertilizer application.

In the upper White River, water temperatures exceed state water quality standards in several locations. The river is listed as a spawning area for Chinook salmon and other salmonids. The river was also listed for sediment levels exceeding state water quality standards. The final TMDL report was approved by EPA in 2004. The implementation plan was completed in 2006. Most of the implementation recommendations were assigned to the U.S. Forest Service (USFS). They are decommissioning roads as funds allow and plantings have occurred, but it takes time to grow trees to a level where they will produce effective shade for the river.