The Town of Hopkinton had a municipal sewer system but did not have a wastewater treatment plant. Their wastewater was being sent to other towns but they were at their discharge limits. A study was conducted to investigate town-wide alternatives and to perform a cost analysis, which led to the construction of a new 350,000-GPD-treatment plant.
An innovative sewer-mining solution was designed that partially diverts flows from an existing sewer main to the new treatment plant. A new surface discharge was impossible therefore a subsurface outfall consisting of a large infiltration basin was proposed. The plant has a capacity of 350,000 GPD and the soil application rate was 3 GPD/sf. Due to the proximity to natural wetlands, the space available for the system was constrained. This problem was solved by a highly efficient chamber infiltration system.
System Specifications: 80,223 square foot infiltration bed for subsurface outfall at new WWTP
Infiltrator Products Used: 4,532 Infiltrator High Capacity H-20 Chambers
System Flow: 350,000 gallons per day