Fuss & O’Neill evaluated and designed improvements for the South Main Street and Washington Street Pump Stations in Rochester, New Hampshire.
The South Main Street Pump Station included three low-head inverted siphons and a wet well, and overflows onto the street occurred each spring. Our new design included 1200 gpm pump station that featured 3 G-R suction lift pumps configured to flow through a valved manifold then into two force mains. All three pumps were fitted with Variable Frequency Drives (VFDs.) During low flow, only one pump discharged to one force main; during highest design flow, two pumps discharged to two parallel force mains. Due to unique site conditions, we opted for a 10×10 foot square, pre-cast wet well and designed the layout based on where the crane could unload the unit and still allow adequate traffic flows.
At the Washington Street Pump Station, we considered and planned for future commercial and residential developments and we upgraded the downstream gravity sewer to accommodate the future flows under the second roadway contract (Brock Street). To lessen the impact on the public, the Washington Street Pump Station was done in concert with two road reconstruction projects.