Existing Collection System Components

The Major Components of the Existing Collection System include:

• Three major interceptors – The Main interceptor, North End Relief interceptor and Belleville Avenue interceptor. The Main interceptor is an 11 mile long conduit ranging in size from 52 – inch to 84-inch diameter. This interceptor can convey approximately 60 million gallons per day (mgd) to the existing wastewater treatment plant. The Belleville Avenue interceptor is 2,500 feet of 42-inch diameter reinforced concrete pipe. The North End Relief interceptor is approximately 16,000 feet of pipe ranging in size from 14 inches to 42 inches.
• Seven major collector sewers – These sewers collect wastewater from various drainage areas and convey the collected wastes to the interceptor system. With one exception (Church Street collector), all of the City’s existing collectors are combined sewers. As such, they are designed to accommodate some stormwater run-off.
• Sixty-four regulators which control the flow of dry and wet weather wastewater entering the interceptor and collector system. These regulators direct flow either to the wastewater treatment plant, or to combined sewer overflows where they are presently discharged to Clark’s Cove or the Inner Harbor without treatment.
• Approximately 186 miles of local lateral sewers that collect wastes from the discharges of individual customers and convey them to the collection sewers.

The system consists of approximately 204 miles of collector sewers, including lateral gravity sewers, force mains and interceptors. Gravity sewers are designed so that the wastewater flows downhill to interceptors. An interceptor is a gravity sewer that transmits large volumes of wastewater to a sewer overflow or a wastewater treatment facility. A force main is a sewer line under pressure in which wastewater is pumped to an interceptor or wastewater treatment facility.