Understanding the Sewer Collection System
Within the JRA service area, the sewer system is a complex network of 20 municipal collection systems all flowing to a single treatment plant. The collection system's underground pipes transport sewage and stormwater by gravity flowing from higher geographic points to lower valleys. In some low lying communities, a pump station may be required to transport the wastewater to an area where gravity can take over again. Ultimately, the wastewater is transported to the Dornick Point Wastewater Treatment Plant for treatment and subsequent release back into the Conemaugh River.
To further complicate the wet weather problem, two types of sewage collection systems exist in the JRA service area—the combined sewer system and the separate sanitary system. Combined sewer systems are designed to carry both wastewater and stormwater in the same pipes. Three local communities, Dale, East Conemaugh, and Ferndale, all still currently utilize this type of system. Each has committed to fully replacing their entire collection systems with separated systems and are in varying stages of achieving that goal.
Combined Sewer System |
Separate sanitary sewer systems are designed to carry only wastewater. Stormwater needs to be managed through a different collection system of pipes, culverts or ditches. Separate sanitary sewers were required for any new systems built after the 1940s.
Separate Sanitary System |
Even with conversion of the combined systems, substantial excess water is collected through illegal connection of public storm drains and private downspouts to the separate sanitary sewers. This water also enters the system through deteriorated lines, manholes, and private laterals.
Example of infiltration: |
Example of inflow: |