Operated by the Sewer Department, the sewer system includes a vast collection system and full scale, state-of-the-art Wastewater Treatment Plant with capacity of 4.0 million gallons per day, complete with a bio-solids dewatering and handling facility, large capacity interceptor sewers ranging up to 27 inches in diameter, and eleven wastewater pumping stations located at strategic points in the system.  The collection system consists of over 113 miles of interceptor and collector lines ranging in size from 6 inches to 27 inches.

Constructed in 2008, the Wastewater Treatment Plant utilizes, a vertical loop reactor process with two settling clarifiers, an effluent pumping station, and an ultraviolet effluent disinfection process.

The sewer system currently serves over 7,000 customers and has the capability to server additional customers in the surrounding area.  The City of Washington provides the full service operations and maintenance of the wastewater collection along with pumping and treatment systems utilizing our duly State licensed operating personnel.

Effective October 1, 2009 all residential, commercial and industrial users of the sewage system maintained by the City of Washington shall pay a fixed monthly service charge of $12.50 per month, to be billed monthly or quarterly.

In addition to the fixed monthly charge set out above, volume charges based upon average winter usage, or monthly service charges, for users of the City sewer system shall be billed monthly or quarterly and assessed as set out in the City Codes.

Residential customers shall be billed for sewer serviced based on actual or estimated average winter water usage based on water meter readings gathered between the months of November and March. This average winter water use shall be used to compute residential sewer billings each April for the next 12 month period. New residential customers who have not established average winter water usage shall be billed on the basis of 5,000 gallons per month until actual average winter water usage has been established.

Commercial and industrial customers shall be billed based on actual or estimated usage based on monthly or quarterly water meter readings or sewer flow metered.

Effective January 1, 2024, for users of the sanitary sewer system within the City limits, the charge shall be $7.00 per on thousand gallons of average winter water furnished to the user.

Effective October 1, 2007 for users of the sanitary sewer system within the City limits, discharging sewer flows in excess of 273 ppm BOD shall be subject to surcharge of $0.15 per thousand gallons of either average winter water or actual water furnished to the user.

Effective October 1, 2007 for users of the sanitary sewer system within the City limits, discharging sewer flows in excess of 363 ppm shall be subject to surcharge of $0.11 per thousand gallons of either average winter water or actual water furnished to the user.  For users of the sanitary sewer system outside the corporate limits of the City of Washington, the charge shall be a rate equivalent to one and one-half (1 ½) times the rate of average winter water or actual water furnished to the user.

For a residential establishment within the corporate City limits of the City of Washington using the City sewer system, and not using the City water system, a sewer service charge of $18.65 per month shall be assessed.

For a residential establishment outside the corporate limits of the City of Washington using the City sewer system, and not using the City water system, a sewer service charge of $35.00 per month shall be assessed.

For a commercial or industrial establishment within the corporate City limits of the City of Washington using the City sewer system, and not using the City water system, a sewer service charged of $181.50 per month shall be assessed. Such rates shall be charged until the establishment is connected to the City water system, from which point the users shall be billed at the then current rate per thousand gallons of actual water furnished to the user plus the then current fixed monthly service charge.

When a commercial or industrial establishment located outside the corporate City limits of the City of Washington is using the City sewer system and is not using the City Water system, the sewer service charge shall be $450.00 per month and shall be billed quarterly. Such rate shall be charged until the establishment is connected to the City water system, from which point the user shall be billed at a rate equivalent to one and one-half (1 ½) times the rate charged commercial or industrial establishments located within the corporate city limits.

To set up services for sewer, please call Utility Billing at (636) 390-1045.

Wastewater Treatment Plant

Old Highway 100 & Mission Drive
Washington, MO 63090
(636) 390-1033