Definition

A major sanitary sewer overflow occurs when sewage overflows the wastewater conveyance system (interceptor pipelines) in an amount greater than 1,000 gallons and/or reaches creeks, rivers or other surface waters.

Target

No more than 1 major sanitary sewer overflow per year.

Purpose

This service level reflects proper capacity, operation and maintenance of major wastewater conveyance (interceptor pipeline) facilities.

Critical Impacts

Critical work activities that influence sanitary sewer overflow performance include planning for adequate system capacity; designing reliable facilities; maintaining facilities to ensure that they are in good operating condition; training staff to assure appropriate operational practices are followed; implementing methods to detect overflows quickly; and implementing response procedures. Even if facilities are managed properly, overflows can occur due to extreme or unusual operating conditions.