How do you bypass a pump station that normally handles 39 million gallons per day?
In July, the City of Jackson, Mississippi began experiencing problems with a 54-inch concrete sewer force main at their Savannah Street water and waste treatment plant. This problematic force main served a vital pump station that pumped several gravity flow lines. The pump station pumped the flow from these lines, through this 54-inch forte main, a distance of 1,100-feet to the plant.
The city personnel needed to re-route the flow of sewage to inspect the 54-inch force main pipe. Thus, the city installed six 12-inch Thompson dry-prime, solids-handling centrifugal sewer bypass pumps that they owned. Having these pumps in inventory quickly paid off. They were able to divert the flow from the pump station to a sewage lagoon, install the pumps at this lagoon, and pump through 700-feet of 12-inch HDPE pipe to the plant. The lagoon served as a reservoir to hold the sewer flow until the diesel pumps became operational. All doing so while using Thompson's exclusive Enviroprime System® which prevents sewage spills.
Once in place and running, the six 12-inch pumps could keep up with the normal flows of the 54-inch force main, which are around 27,500 GPM (39 MGD). However, in the event of a large rain, a major spill could occur. To prevent spillage during a large rain, Thompson Pump Representative Jim Templeton installed an 18JSCr an I8-inch solids-handling dry-prime compressor-assisted Enviroprime® pump, which could produce an additional 8500 GPM (12 MGD). With this added capacity, the system could handle flows in a rain event and also pump down the surcharge in the lagoon.
The force main was successfully rehabilitated.