Anticipating new EPA regulations for water treatment, including the Enhanced Surface Water Treatment Rule and the Disinfectant/Disinfection Byproducts Rule, the City of Minneapolis began to explore options for enhancing its treatment processes. Currently, Minneapolis Water Works (MWW) serves almost 500,000 customers. MWW's current operations are comprised of 12 pump stations, a softening plant, two filtration plants, a dewatering plant, seven reservoirs with a total capacity of 160 million gallons and the distribution system.
The City of Minneapolis hired HDR to evaluate MWW's water treatment processes and facilities, assess alternatives to meet current and future water quality regulations and develop an improvement plan to meet the needs for the next 10 to 20 years. The assessment confirmed the need for MWW to consider advanced technologies for balancing required increases in microbial disinfection with reductions in disinfection byproducts (DBPs). In conjunction with the disinfection/DBP balance, water quality parameters of concern for the system included turbidity and total organic carbon (TOC). A variety of studies were conducted to evaluate advanced treatment options with the above considerations.
The membrane systems would be selected based on the side-by-side testing of qualified, commercially available membrane filtration systems. This would allow the development of an accurate membrane filtration design prior to the subsequent design of the facilities. HDR produced procurement documents for both facilities that required successful completion of performance testing before an analysis of the bid price.
HDR will continue to be involved in special testing, data analysis, and pilot operation and maintenance oversight. Upon completion of these treatment plants, MWW will be one of the largest membrane treatment systems in the world. Throughout our work with MWW, HDR has provided the MWW with advice on membranes through a team of gathered membrane experts. The Peer Review Panel, consisting of technology experts from around the country, provides reviews and comments on key documents and decisions. HDR's constant involvement in and commitment to the membrane pilot testing and overall program management convinced MWW that we are determined to meet MWW's goal of producing high-quality water from a combined 160 MGD of membrane.