CSOs Explained

What is a CSO?
Combined Sewer Overflows (CSOs) are an overflow of sewage and stormwater into Puget Sound. They occur as a direct result of stormwater entering the sanitary sewer system. Stormwater entering the sanitary sewer system uses the available system capacity and as the pipes fill and wastewater pump stations reach their capacity a CSO event can occur.

Combined System

View this animation in Flash:

Download this animation in one of these formats:

Separated in the Right of Way

View this animation in Flash:

Download this animation in one of these formats:

Separated System - Ideal

View this animation in Flash:

Download this animation in one of these formats: