Water Quality Improvement Project
The Colville River watershed in northeastern Washington State is
approximately 1,020 square miles in area. The river’s headwaters are the
confluence of Sheep Creek and Deer Creek just north of the town of Springdale.
From the headwaters, the river flows north 53 miles to Kettle Falls where it
empties into the Columbia River. This drainage basin is bordered by mountains
ranging in elevation from about 5,000 to 7,000 feet. Some of the Colville
River’s major tributaries include Jump-Off-Joe Creek, Chewelah Creek, Little
Pend Oreille River, and Mill Creek. Stream flows in the Colville River typically
peak in April or May and the lowest flows usually occur July through October.
Stevens County has a population of over 40,000 people and the major industries
include timber, agriculture, mining, recreation and tourism.
Water quality issues
Ecology placed several segments and tributaries of the Colville River on the
1998 Water Quality Assessments of impaired water bodies [the 303(d) list]. They
exceed the water quality standards for dissolved oxygen (DO), ammonia, chlorine
and fecal coliform. Ecology developed two TMDLs as a result of these 1998
- Colville River Dissolved Oxygen TMDL (which also addressed ammonia)
- Colville River Watershed Bacteria TMDL
Both ammonia and chlorine are produced by the wastewater treatment process
and can be toxic to aquatic life. Fecal coliform bacteria occur naturally in the
digestive tract of warm-blooded animals to help digest food. Sources of fecal
coliform bacteria pollution in the Colville River watershed include waste from
humans (leaking septic systems), domestic animals (cattle, horses and pets),
birds and wildlife.
Now that the Environmental Protection Agency (EPA) has approved the TMDLs,
Ecology's 2004 Water Quality Assessment lists these river and tributary segments
as Category 4a: Has a TMDL.
Why this matters
Ammonia (NH4+) 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.
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.
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.
What is being done
To address the ammonia and dissolved oxygen problems, Ecology completed a
water quality improvement plan or total maximum daily load (TMDL) for the cities
of Chewelah and Colville wastewater treatment plants. Both cities built new
wastewater treatment plants and the wasteload allocation targets in the TMDLs
were placed in their permits. The treatment plant upgrades will allow the
treated wastewater discharge to meet the permit limits and protect aquatic life.
Both treatment plants use ultraviolet light instead of chlorine for
disinfection, so chlorine will no longer be a problem in the Colville River.
Ecology worked with an advisory group of local citizens to complete a TMDL
for fecal coliform bacteria. After EPA approved the TMDL, the same group wrote a
Detailed Implementation Plan (now called a Water Quality Implementation Plan).
The implemenation plan listed several actions landowners and various entities
may use to reduce bacteria in the watershed. The plan also includes a table of
actions local agencies or organizations felt they could take to improve water
quality in the watershed.
Status of the project
The city of Chewelah began operating their new wastewater treatment plant in
January 2002. The city of Colville began operating their new wastewater
treatment plant August 1, 2006.
In the water quality implementation plan for fecal coliform, several agencies
or organizations identified steps they could take to improve water quality in
the watershed (see Table 5 of the implementation plan). A public meeting was
held on January 4, 2007 to review progress on reducing bacteria levels. Ecology
records information on the status of each agency’s or organization’s activities
in Appendix A of the implementation plan. If you have any questions about the
progress of the TMDL’s implementation contact us.
Unless otherwise specified, the files below are Ecology publications.
Ammonia and dissolved oxygen documents:
Fecal Coliform Bacteria documents:
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