The key manhole program: pollution source control for the King County sewage system

In the King County sewage system, all wastewater from each sector of land flows through a central point known as a key manhole. KCIW compliance specialists sample discharges from selected key manholes. Then they prepare data to track what is normal and to spot changes or anomalies.

This program uses key manhole investigations to stop harmful waste from adversely affecting sewage treatment plants and surface-water quality.

Industrial discharges to the sewer often have characteristics typical of specific industries. Illegal discharges to the county sewage system can often be traced to a specific industry in the sector of land that feeds the key manhole when KCIW traces specific discharges to a local industry.

Report suspicious or illegal discharges to the county sewage system (see Contacts, left.)