Wastewater & Stormwater

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Wastewater Treatment

Clarkston operates a Level III Wastewater Treatment Plant (WWTP). The Clarkston Wastewater Division is responsible for operating and maintaining the collection and treatment processes to ensure the City is in compliance with all applicable state and federal clean water standards. The wastewater collection system consists of 26.1 miles of main lines and one lift station. The City also receives and treats wastewater from Asotin County’s collection system. The plant is designed to treat up to 2 million gallons per day.


Sewer Rates

Sewer service is billed at the beginning of the month, and payment is due by the last business day of the month. A $10.00 late fee will be assessed if your balance is not paid by the 15th of the following month.

Both residential and commercial bills are based on a base fee plus a charge for each unit of water used. Water usage is provided to the City by Asotin County PUD for the months of January and February. The City then determines an average water usage for those months, and based on that average, recalculates the monthly sewer charge each April. This charge remains in effect until the next year’s calculation. For properties without a current water history or an incomplete water history for the study period, the sewer charge will be based on the “average” sewer rate for the property’s classification.

Owners of properties that experience unusually high amounts of water usage due to a water leak may apply for a sewer adjustment once repairs have been made and documentation provided. Requests for adjustments must be made within 90 days of repairs. Contact City Hall for details. If a property will remain vacant for an extended period of time (at least 45 days), the property owner may apply for “vacancy” charges by completing and filing the necessary form with City Hall. Visit the links below to find up-to-date utility rates for the City of Clarkston.

Stormwater Management Program

The City of Clarkston, in cooperation with Asotin County and the City of Asotin, has developed a stormwater program as required by the State of Washington Department of Ecology. To learn more about our stormwater management efforts and how you can help, please follow the link below to the Asotin County website.