In order to reduce the total volume of Combined Sewer Overflow tributary to the Yonkers Combined System, peak wet weather capacity of Alexander, Main and Ludlow Street wastewater pumping stations were increased. Because of facility configuration, cost and other restrictions, this increase had to be accomplished within the existing structures of the stations.

Savin Engineers' design for each facility included new pumps, suction and discharge piping, supports, controls and alarms. The Ludlow and Main Street Pumping Stations, 4 and 9 mgd. design facilities respectively, were converted from submersible stations to wet/dry types. The hydraulic analyses for these two pumping stations centered around their discharges to an existing 54 inch force main that conveys up to 70 mgd. The Alexander Street Pumping Station, with a design flow of 12 mgd., required significant wet well modification to improve pump cycle times. Water hammer analysis was performed for all three pumping systems.