Water Quality Improvement Project
Crystal Creek:


Crystal Creek is located outside the town of Roslyn, in the upper Yakima River valley. It drains 7.7 square miles of forested foothills in the Roslyn and Cle Elum area. There are a number of tributaries associated with Crystal Creek whose sources are springs in the foothills and along the edges of Roslyn.

Water quality issues

Studies determined that pollutants, like fecal coliform bacteria, chlorine, and nutrients, were entering Crystal Creek from several sources. Leaking sewer lines in Roslyn introduced pollutants into the creek. Wastewater from a sewage treatment lagoons drained into the creek from an open ditch. Drainage from a nearby mine also entered the creek.

Crystal Creek, Washington State.  Photograph courtesy of Jane Creech, WA Department of Ecology.

Why this matters

Ammonia is one measure of nitrogen, a nutrient that can increase the growth of plants and algae in water. When higher-than-normal levels of nutrients are present, plants and algae can get out of control and lead to changes in the water’s pH, dissolved oxygen and clarity. In addition, increased algae and plants can be ugly, create odor problems when they die, decompose and interfere with recreational activities like boating and swimming. It is also highly toxic to fish and other aquatic life, even in very small amounts.

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. It can be used to measure the amount of water pollution in a water body.

Chlorine is widely used to disinfect municipal wastewater. Chlorine can irritate the skin and mucous membranes of fish, even at low levels. If it combines with ammonia in the water, the resultant product can pass through fish gills and enter the bloodstream, preventing oxygen from entering the blood and causing suffocation.

Fecal coliform is a type of “bacteria” common in human and animal waste. It can make people sick and cause the closure of shellfish harvesting beds. Bacteria can get into our waters from untreated or partially treated discharges from wastewater treatment plants, from improperly functioning septic systems, and from livestock, pets and wildlife.

Status of the project

Ecology submitted a Total Maximum Daily Load (TMDL) to EPA for approval. The TMDL set wasteload allocations for the town of Roslyn's wastewater treatment plant. EPA approved the TMDL in February 1993. A National Pollutant Discharge Elimination System (NPDES) permit was issued to the wastewater treatment plant in 1995.

Technical information

Crystal Creek Multi-parameter Total Maximum Daily Load

Roslyn Wastewater Lagoons and Crystal Creek Receiving Water Study -- Findings. Memo to Chris Haynes and Harold Porath (Ecology publication)

Related information

Roslyn Post-Upgrade Wastewater Treatment Plant Limited Class II Inspection and Receiving Water Study on Crystal Creek

Concentrations of 303(d) Listed Metals in the Upper Yakima River

WRIA 39: Upper Yakima Watershed Information (Water web site)


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Last updated May 2012
  Water resource inventory area (WRIA) 39 map, Washington State.


WRIA: #39 (Upper Yakima)


Water-body Name:
Crystal Creek

BOD (5-day)
Fecal Coliform

# of TMDLs: 4

Approved by EPA

Contact Info:
Jane Creech
Phone:  509-454-7860
Email:  Jane.Creech@ecy.wa.gov

Central Region
Department of Ecology
1250 West Alder Street
Union Gap, WA 98903-0009