Water Quality Improvement Project
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.
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
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.
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)
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