Puyallup River basin TMDLs

The Puyallup River drainage basin covers approximately 970 square miles in the Puget Sound lowlands. We are working in this basin to address several water quality impairments. The major streams of the basin are the Puyallup River and its two largest tributaries, the White and Carbon rivers. The lower reach of the Puyallup River is a relatively flat floodplain ranging in elevation from sea level at Commencement Bay to approximately 50 feet at the confluence of the White and Puyallup rivers.

Water bodies in the Puyallup River basin have been listed for several parameters because they did not meet state water quality standards. Parameters of concern include: biological oxygen demand (BOD), ammonia, fecal coliform bacteria, pH, sediment, and temperature.


We're working to improve water quality 

Several water quality improvement projects, or total maximum daily loads (TMDLs), have been completed that cover a variety of parameters including fecal coliform bacteria, BOD, ammonia, and temperature. See the completed projects section below.  

While the reports are completed, we continue to work with partners in the Puyallup River watershed to implement actions in the TMDLs. Implementation work includes increased education and outreach, a greater field presence to identify and eliminate nonpoint sources of pollution, and working with permit managers and permittees to ensure TMDL point source requirements are met. 

Draft cleanup plan for Lower White River

We collaborated with the Muckleshoot Indian Tribe and the EPA to develop a draft Lower White River pH water cleanup plan (TMDL). Once finalized and implemented, this plan should help reduce pH, bringing it back to a level that’s healthy for fish and other aquatic life. The goal of the cleanup plan is to limit nutrients and describe best management practices (BMPs) needed to reduce phosphorus pollution. The plan is split into two reports. The technical document describes our monitoring, analysis, and assigns wasteload and load allocations. The implementation plan details the actions needed to address water quality impairments. 

White River flows through the Muckleshoot Indian Tribal Reservation. We do not have the legal authority to establish TMDLs on tribal property. Instead, the TMDL sets aside a ‘reserve’ of the allowable pollution load to accommodate current and future Tribal discharges while supporting Muckleshoot Tribe fish production. 

Water quality issues

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. This is especially true during the summer months when there is more light, warmer temperatures, and lower water levels. 

Where are these excess nutrients coming from? 

The two largest point source contributors are the wastewater treatment plants at the cities of Buckley and Enumclaw. The cleanup plan also addresses phosphorus from several permitted sources, including municipal, construction, industrial stormwater, and sand and gravel permittees. Nonpoint nutrient control focuses on promoting BMPs like proper manure storage and fertilizer application.

We received feedback on our draft plan

We held a public comment period on the draft Lower White River TMDL and implementation plan documents from June 16, 2022, until 11:59 p.m. July 31, 2022. Comments are no longer being accepted on the draft plan. Responses to comments will be included as an appendix to the report. The plan is currently being revised to include comments and responses before submittal to EPA. 

Completed projects

Why this matters

Ammonia is a measure of nitrogen, a nutrient that can increase the growth of plants and algae in water. Large concentrations of ammonia in a stream or lake can create a large oxygen demand caused by the conversion of ammonia to nitrate, called "nitrification." High concentrations of nitrate in wastewater treatment plant effluent can cause algae to grow. Dead and decaying algae can cause oxygen depletion which can kill fish and other aquatic organisms in streams. Higher-than-normal levels of nutrients in the water can also change the water’s pH and clarity. In addition, increased algae and plants can be ugly, create odor problems when they decompose, and interfere with recreational activities like boating and swimming.

Biological Oxygen Demand (BOD) is the amount of oxygen required by aerobic microorganisms (organisms that need oxygen to survive) to break down organic matter in water.

Fecal coliform is a type of bacteria found in the feces of warm-blooded animals and humans. When found in water bodies it can be an indicator of the presence of other disease-carrying organisms. It can get into water bodies from failing septic systems and animal waste. High levels of fecal coliform in the water can affect the economy, public health, and environmental quality.

pH measures how acidic or basic something is, ranging from 1 to 14. Low pH is acidic, high is basic. Fish and other aquatic species thrive in water with pH values between 6.5 - 8.5 (7 is considered neutral). If the pH is too high, it is considered harmful for fish and other aquatic species.

Too much sediment in the water can irritate fish gills and make it difficult for them to breathe. It also suffocates salmon egg nests.

Water temperature is important to fish and aquatic species. Threatened and endangered salmon need cold, clean water to survive. If the water is too warm, the salmon are less able to successfully spawn, and may suffer other health effects.