As of December 5, 2022, a design engineer has been selected. Bidding is anticipated to take place in the fall of 2023. *The previous solicitation is listed below for reference The Board of Water Works Trustees of the City of Des Moines, Iowa, (DMWW) is requesting proposals from qualified consulting engineering firms licensed in the state of Iowa to team with DMWW to provide design, bidding, and construction services for the water transmission improvements associated with the Saylorville Water Treatment Plant (SWTP) expansion from 10 to 20 million gallons per day (MGD). Des Moines Water Works is an independently operated municipal utility providing drinking water to more than 600,000 customers in the Des Moines and surrounding metropolitan area. Over 20 central Iowa cities, rural water districts, and other entities located in Polk, Warren, Madison, and Dallas counties are served by DMWW. DMWW owns and operates three water treatment plants: Fleur Drive Water Treatment Plant (FDWTP), L.D. McMullen Water Treatment Plant (MWTP), and Saylorville Water Treatment Plant (SWTP). The total combined treatment capacity is approximately 110 MGD. The sources of supply include the Raccoon River, Des Moines River, infiltration ponds, and infiltration piping at FDWTP; Maffitt Reservoir, Crystal Lake, and several alluvial groundwater wells at MWTP; and alluvial wells at SWTP. Each treatment plant, from a regulatory perspective, is considered a surface-water treatment plant. All alluvial collection systems are considered ground water under the direct influence of surface water. FDWTP (75 MGD) and MWTP (25 MGD) are conventional lime-softening water treatment plants. Portions of the FDWTP have been in operation for over 100 years and MWTP was commissioned in May of 2000. SWTP (10 MGD) is a membrane filtration plant (Ultra Filtration (UF) / Reverse Osmosis (RO)) that was commissioned in 2011. The treatment process is sourced by two radial collector wells constructed along the banks of the Des Moines River. Treatment works include a pre-treatment step to allow for proper oxidation and coagulation of iron and manganese. After pre-treatment, all water passes through UF membranes and then a percentage of flow is also directed through RO membranes to meet hardness and other treatment or regulatory goals. Aeration, fluoridation, and disinfection complete the treatment process. The initial treatment plant design had a capacity of 10 MGD, while planning for an additional 10 MGD expansion within the initial building footprint. The method of Contractor Selection has not been Determined at this time.
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