Lift Station Improvement Project On January 30, 2008 the Board of Trustees approved an Engineering Services Agreement with Veenstra & Kimm, Inc., for Lift Station and Force Main Improvements. The improvements will increase the pumping capacity to 600 gpm through the construction of a new wet well and pump; provide backup electrical generation; provide force main operational redundancy to quickly mitigate any potential hazards should there be a pipe failure under the Middle Raccoon River through the installation of a new 8-inch force main from the lift station to the lagoons; and help CRMU meet IDNR compliance regulations.
Staff reviewed and edited preliminary plans with V&K in December 2008. The project is anticipated to be let for bids in March of 2009.
Reduction of I&I Starting in 2009, CRMU will begin the process of documenting the condition of our wastewater collection system. Upon CRMU's last NPDES permit renewal, CRMU was mandated to submit a "Plan of Action - POA" for getting into compliance with the permit. CRMU was exceeding its permitted influent capacities (due to inflow and infiltration - I&I) and had to develop a plan for how it would get back into compliance. CRMU contracted the services of H.R. Green Consulting Company to help develop and implement the POA.
As part of the POA, strategic manholes were selected for metering purposes to monitor flows. These "actual" flows were compared to computed per capita flow levels to help determine which areas of CRMU's collection system should be focused on (i.e. experiencing higher than normal flows). The metering resulted in CRMU video taping and smoke testing specific segments on the west side of Coon Rapids. This additional inspection led to the grouting of several manholes and the elimination of one large cross-connection with the storm sewer at the intersection of 6th Avenue and North Street. While these maintenance activities helped, CRMU continues to experience wet weather flows in excess of permitted levels.
In efforts to manage CRMU's wastewater collection system in a cost-effective manner, CRMU will be pursuing a long-term proactive approach to improving the overall condition of the collection system. While it is obvious that our collection system has I&I issues, it is anything but obvious to the most cost effective mitigation solution(s). CRMU could waste thousands of dollars in attempts to mitigate I&I if we don't understand or "know" the entire picture. Before financially sound recommendations can be made, it is essential that CRMU know the condition of its facilities (i.e. video taping of system).
CRMU plans to thoroughly clean and video tape the entire system over a three-year period. During this time, we will verify and document every "wye" connection to the wastewater system. In this process, CRMU will also be videotaping each service line and inspecting each building for inappropriate connections to things such as sump pumps, perimeter drains and down spouts. This information will be essential in formulating future collection system improvements.
