Water Quality Improvement Project
Dragoon Creek is a tributary to the Little Spokane River. It meanders
through pastures and fields to the west of the city of Deer Park, which
is north of the city of Spokane. Dragoon Creek is a tributary to the
Little Spokane River. Dragoon Creek is designated a Class A stream under
Washington Administrative Code (WAC) 173-201-070(6) and WAC
173-201-080(a5). Class A designations cover characteristic uses
such as water supply; wildlife habitat; livestock watering; general
recreation, aesthetic enjoyment; and fish reproduction, rearing, and
Land use in the area of Dragoon Creek is mostly grazing for small herds of
livestock, and small farm operations. Several game fish species were
resident in the creek in the late 1970s - early 1980s.
Water quality issues
In the early 1980s, the Deer Park sewage treatment plant (STP) discharged
into Dragoon Creek. During that time a water quality study found
elevated levels of nitrogen and phosphorus. The study also found that
the water was "enriched" with nitrate, ammonia, and orthophosphate prior
to the STP discharge. Runoff from agricultural land was suspected,
but not documented. The stream was also impacted with residual chlorine
and ammonia from the Deer Creek wastewater treatment plant (WWTP), along with biological oxygen demand
and dissolved oxygen issues.
Dragoon Creek was later listed as impaired for fecal coliform and dissolved
oxygen on the 1996 Clean Water Act (CWA) 303(d) list.
Why this matters
Ammonia (NH4+) is one measure of nitrogen, a nutrient that can
increase the growth of plants and algae in water. The presence of large
concentrations of ammonia in a stream or lake can create a large oxygen
demand. This demand is caused by the conversion of ammonia to nitrate,
called "nitrification". High concentrations of nitrate in wastewater
treatment plant effluent can cause algae to grow in large quantities.
Dead and decaying algae can cause oxygen depletion problems, which in
turn can kill fish and other aquatic organisms in streams.
Higher-than-normal levels of nutrients in the water can also lead to
changes in the water’s pH 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.
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.
Fecal coliform is a type of “bacteria” common in human and animal
waste. It indicates that sewage or manure is entering a water body. As the level
of fecal coliform increases the risk of people getting sick from playing or
working in the water increases. 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.
People can help keep bacteria out of the water. Properly collect, bag, and
trash dog poop. Check your on-site sewage system to make sure it is maintained
and working properly. Ensure livestock and manure are kept away from the water.
Oxygen dissolved in healthy water is vital for fish and aquatic life
“breathe” to survive. It is more difficult to transfer oxygen from water to
blood than it is to transfer oxygen from air to blood. Therefore, it is critical
that an adequate amount of oxygen is maintained in the water for this transfer
to take place efficiently and sustain aquatic life. Oxygen is also necessary to
help decompose organic matter in the water and bottom sediments as well as for
other biological and chemical processes.
Phosphorus fuels the growth of algae. When algae die, they remove
oxygen from the water. Fish and aquatic life need oxygen to survive.
Status of the project
In 1985 Deer Park stopped discharging treated wastewater to Dragoon Creek. In
March 1992 Ecology developed a total maximum daily load (TMDL) for the creek for
ammonia-nitrogen, chlorine, and total phosphorus. The TMDL prescribed a
zero-discharge waste load allocation for the Deer Park WWTP. The Environmental Protection Agency approved the TMDL in February 1993.
Dragoon Creek is currently on the
water quality assessment 303(d) list of
impaired waters for dissolved oxygen and fecal coliform bacteria.
Dragoon Creek BOD Total Maximum Daily Load (Ecology Publication)
Dragoon Creek Receiving
Water Study/Deer Park STP. Memo to Carl Nuechterlein (Ecology Publication)
Little Spokane River Water Quality Improvement Plan Information (Ecology
Reducing Phosphorus Pollution to Improve Water Quality (Ecology web site)
WRIA 55: Walla Walla
Watershed Information (Water web site)
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