HOW DOES SEWAGE GET TO THE TREATMENT PLANTS?
Sewage travels through three different sets of pipes. Water that is used in a home or industry is flushed through a building’s pipes until it reaches local sewers which are owned and operated by city and town sewer departments. These 5,100 miles of local sewers transport the wastewater into 227 miles of MWRA interceptor sewers. The interceptor sewers, ranging from 8 inches to 11 feet in diameter, carry the region’s wastewater to two MWRA treatment plants. Though most of the wastewater flows by gravity some low-lying areas require pumping. HOW DOES SEWAGE TREATMENT WORK? MWRA provides preliminary primary and secondary treatment to its wastewater flows at the Deer Island Treatment Plant. The first phase of secondary treatment began operating in July 1997. The treatment process is as follows: Collection and Pumping Sewage is piped from communities to several headworks where bricks, logs and other large objects are screened out. Pumps draw the sewage through deep-rock tunnels under the har
