Sudbury Housing Authority

The Sudbury Housing Authority (SHA) has two separate wastewater collection and disposal systems, i.e., the north system and the south system. Each system is comprised of gravity sewer pipes, a 7,000-gallon septic tank, and a submersible pumping station that discharges through a force main to two separate leach field systems that are selected by opening and closing two isolation valves. Both of the pump station wetwells had major concrete deterioration caused by hydrogen sulfide gas production due to too long residence time. Additionally, the control panels were antiquated and needed replacing. The Sudbury Housing Authority retained Graves Engineering, Inc. (GEI) to design two (2) replacement pump stations. GEI provided topographic survey, bid phase, construction administration and periodic inspection services. The project included the following:

Pump Station No.1

• 4-foot diameter pre-cast concrete wetwell with duplex 17 GPM, 2 HP submersible grinder pumps.
• 420 feet of 1.5" HDPE Pipe Force Main installed by slip lining.
• 10 feet of 6" diameter SDR 35 PVC Gravity Sewer.
• 1,400 feet of 2.5" diameter SCH 40 PVC Electrical Conduit.

Pump Station No.2

• 4-foot diameter pre-cast concrete wetwell with duplex 20 GPM, 2 HP submersible grinder pumps.
• 60 feet of 1.5" diameter SDR 21 PVC Force Main.
• 30 feet of 6" diameter SDR 35 PVC Gravity Sewer.
• 100 feet of 2.5" diameter SCH 40 PVC Electrical Conduit.