Sioux Falls Pump Station 240 Improvements

Challenge: The City of Sioux Falls, South Dakota, is home to a growing community of approximately 213,000 residents. To accommodate growth and increased demand, the City needed to address the capacity of its Pump Station 240, originally designed and constructed by a joint team of HR Green and another consultant in 2007. PS240 has a capacity of approximately three million gallons per day (mgd) through the 16-inch force main to the Water Reclamation Facility (WRF) and serves the City’s eastside.

Solution: The City’s Engineering group engaged HR Green’s team in extensive pre-design discussions. These included collections, maintenance, and planning to determine the project service area, flow capacity requirements, and alternatives.

The project design included multiple evaluations to optimize the design, such as an evaluation of the electrical service provider, electrical rates, and the impact lower electrical rates have on the project payback period. The evaluation also addressed alternatives for a large pump station or an intermediate pump station. Other design complexities included the coordination of two Burlington Northern Railroad crossings, the Big Sioux River crossings, and WRF expansion.

The City has tackled the project in two phases. Phase 1 included the addition of a 10-million-gallon equalization basin at the Pump Station 240 site. Additional pumps were added in PS240 for equalization basin operation and to increase pump station capacity. The 10-million-gallon earthen equalization basin was constructed on a steep site with grading constraints.

Phase 2 consisted of the 30-inch force main from Pump Station 240 to the WRF. The force main length is approximately 52,000 feet. The alignment was selected in the predesign phase of the project and generally follows 57th Street from Pump Station 240 west to Highway 100. Due to funding challenges, the project is expected to be constructed in three additional bid packages with construction occurring in 2024 through 2026.

Benefit: The Pump Station 240 facility is a legacy project for HR Green and demonstrates the firm’s commitment to the community of Sioux Falls. In addition to creating a lasting solution for the City’s equalization basin and water facility design, HR Green helped the community by evaluating the alternatives and ultimately helping the City create a best-fit design through the use of the equalization basin solution and optimization.