THE OPPORTUNITY

As part of a flood protection system to prevent damage to the PVSC treatment plant from storm surges such as that which occurred during Superstorm Sandy, PS&S performed a conceptual design for two storm water pump stations and upgrading of tributary existing storm drainage systems. The treatment plant sustained considerable damage during Superstorm Sandy, which not only affected the plant’s ability to treat incoming wastewater but also produced long term repercussions throughout PVSC’s service area. The PVSC treatment plant has an east side and a west side separated by a public street. The flood protection system also included a flood wall system, consisting of a continuous flood wall for each side of the plant. The overall protection scenario also includes an on-site standby power system.

THE CHALLENGE

PS&S evaluated several alternatives considering factors such as environmental constraints, permitting, social impacts, design challenges, availability of land, constructability, economics, and effectiveness in achieving the mitigation purpose. The recommended scenario included an on-site back-up power system, a flood wall for each side of the plant to protect the power system, electrical substations, critical process areas, equipment galleries, utility tunnels, and other support areas, an upgraded storm drainage system, and pumping stations to pump collected storm water within the flood wall areas.

THE PS&S SOLUTION

The pumping stations were each designed as submersible style with coarse mechanical bar screen, sized to handle 100 year rainfall. The East Side station was designed for approximately 75,000 gpm, including 4- 25,000 gpm pumps and 3- 10,000 gpm pumps. The West Side station was designed for approximately 150,000 gpm using 5- 30,000 gpm pumps and 3- 18,000 gpm pumps. The project is being funded through the FEMA Hazard Mitigation Grant Program (HMGP).