Falcon Lakes Sanitary Sewer Main Extensions
The objective of this project was to provide sanitary sewer collection to an unserviced area to support the development of a 600 acre golf course community while providing for future development of the surrounding basin. The design and construction of the project was completed under contract with the City of Basehor which financed the project via a benefit district. The costs were then assessed to all properties within the basin to allow for an equitable sharing of expense.
Construction consisted of 8,500 feet of sanitary sewer interceptor line with sizes up to 24" and nearly 11,250 feet of lateral sanitary sewers. The design of the project included a 3.6 mgd pump station with pumps adequately sized for the ultimate development of the watershed while providing multiple impellor options and force main phasing for cost effective upgrades. A phasing plan was created for increasing capacity as the basin development, 10,500 feet of parallel 8" and 10" force mains were constructed. Allowances were also made for a force main that would be constructed later as additional capacity was needed.
Several challenges presented themselves during the design phase given the existing conditions and the need for minimal impact on a 200 acre golf course and associated 55 acre lake. The sanitary sewer interceptor line reached depths of 30 feet which demanded design considerations of groundwater, unstable soil conditions and floodplain areas. Challenging topography in other areas required the use of an aerial crossing to avoid conflicts with the lake. The pump station wet well was approximately 30 feet deep and construction in unstable, saturated soils therefore special design considerations were needed to overcome these issues. The pump station design also included the necessary controls and instrumentation to allow the city to remotely monitor the station.