The District’s direct sewer services consist of the ownership and operation of the local wastewater collection system. Regional conveyance of wastewater and sewage treatment is provided under contract by King County Wastewater Treatment. The District entered into an agreement for sewage disposal with King County in 1973. Under the agreement the District is obligated to transmit all wastewater from District sewer customers, and King County is obligated to provide all regional conveyance system needed to transmit wastewater from the District, and provide wastewater treatment. The contract for services runs through July 1, 2036.

Under the contract, the District is billed based upon a quarterly report of sewer customers submitted to King County Wastewater Treatment. King County bills the District monthly for each single-family residential customer reported, and for a net residential customer equivalent based on the amount of water consumption reported for all non-single family customers. King County Wastewater Treatment charges are passed directly on to District customers. As such, as the cost for this service increases, the District adjusts rates to compensate for increases in its direct cost.

In addition to monthly user charges, since 1990 King County Wastewater Treatment has levied a capacity charge on new connections to the sewer system, which these new customers pay in addition to their monthly sewer bill. The capacity charge helps King County cover the cost of sewer improvement and expansion projects needed to serve new growth. Newly connecting customers are directly billed by King County for the capacity charge.

To learn more please visit the King County Wastewater Treatment Division website.