Faced with continuous growth and development, the City of Fargo retained AE2S to complete a Wastewater Collection System Master Plan (CSMP), followed by a 45th Street Corridor Facility Plan in which necessary growth-related infrastructure improvements were identified. Building upon the recommendations of these reports and the need for expanded capacity in the City’s Wastewater Collection System, the City has implemented plans for construction of a third major interceptor sewer, the 45th Street Corridor, from south Fargo to north Fargo, where the City’s Wastewater Treatment Facility (WWTF) is located. To address expansion of the City’s interceptor sewer system to serve new growth areas and provide wet-weather flow relief for a portion of the City’s existing collection system, the City retained AE2S to provide professional services in conjunction with the design and construction of a new lift station.
Planning analysis has indicated that the new County Road 20 (CR20) Lift Station will require a peak capacity of 50 million gallons per day (MGD). A substantial portion of the flow that reaches the station will be pumped from an existing lift station, with additional flow from the growth areas as well as peak overflow from existing sewer infrastructure. The CR20 Lift Station will pump the collected wastewater through two new force mains, either to the WWTF or directly to the existing Wastewater Stabilization Ponds (WWSPs), since the ultimate lift station capacity exceeds the design capacity of the existing WWTF. At times, it may be necessary to pump wastewater to both destinations simultaneously to provide complete flexibility. The operations of the CR20 Lift Station will be critical to ensuring the vision established for the 45th Street Corridor Interceptor System is fully implemented. Since the ultimate plan for the CR20 Lift Station is to act as a remote influent pump station to the WWTF, the facility will be equipped with advanced features such as complex control logic associated with the multiple discharge destinations, standby power, and odor control provisions.
Both liquid and vapor phase technologies were employed at the new County Road 20 Lift Station to minimize odors generated in the large interceptor system. A dual stage carbon system with impregnated media was designed to treat the fugitive odors which may be generated at the lift station site. In addition to treating the odors at the lift station site the City has been feeding iron salts at an existing lift station that will ultimately be rerouted to this lift station as part of the overall interceptor system improvements. In order to maximize the potential of the iron salts the City completed piloting of the US Peroxide’s PRI-SCTM process. As a result of the piloting it was determined that the addition of hydrogen peroxide at this lift station site would regenerate the iron, reduce the overall chemical consumption, and help minimize odors generated downstream at the wastewater treatment facility headworks. Consequently, a hydrogen peroxide feed and storage system was incorporated into the design of the lift station improvements.