About the Sewer System

Wastewater from homes and businesses travels through miles of sewer lines to get to our Plum Island Wastewater Treatment Plant. The sewer system, or wastewater collection system, consists of 780 miles of sewer lines (including gravity pipe and pressurized force mains), more than 185 pump stations, and 16 miles of deep tunnels.

Our Wastewater Collection Department is responsible for operating and maintaining the sewer system, including cleaning manholes, conducting smoke and dye testing to reduce infiltration and inflow, and other corrective and preventative maintenance activities.


In 2009, our Wastewater Collection department received a National Environmental Achievement Award from the National Association of Clean Water Agencies for its Infiltration/Inflow Reduction Program. This project eliminated sources of rainwater in the sewer system, which takes up needed capacity and can cause sewer overflows during heavy rainfall.

Partnership for Clean Water

Our Plum Island Wastewater Treatment Plant became a charter member of this organization in early 2017. We proudly progressed to Phase II facility status on June, 7 2017. Our next step is to complete the comprehensive wastewater treatment facility self-assessment process, making the facility eligible to receive the Phase III Directors Award.

Video: Three Things You Should Know About Your Sewer Service

Check out our latest Sewer Service Report!

2014 Sewer Service Report - Charleston Water System