Agenda - Council - 10/08/2019 - Laserfiche WebLink

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Water Treatment Once a source water has been selected/confirmed, SEH will review the treatment goals and processes most commonly and cost-effectively used for used for municipal water treatment, This work will include an analysis of the municipal hardness removal including lime softening, reverse osmosis and ion exchange softening. In previous feasibility studies, SEH has included incremental costs of municipal water softening versus the cost of in -home softening. SEH will evaluate water treatment plant options including gravity and pressure filtration for iron and manganese removal. Pressure filtration is likely to have lower capital costs and could more easily incorporate the existing ground storage reservoir. However, gravity filtration offers operational advantages and may have lower life cycle costs. We will also share our positive experiences with designing and operating biologic filtration plants with the project team to show how this technology can be incorporated into your project, After the treatment goals and treatment process options have been identified, the Project Team will sit down and discuss the advantages and disadvantages of each process. The Project Team will take tours of select water treatment plants across the region to help the Ramsey Staff get a better understanding of the various treatment processes. The Preliminary Design Report will document the discussions and observations made on the advantages and disadvantages of each process so that City staff can select the process that works best for your needs. Plant Layout - Filter Size and Design Features Selecting the proper filter size is critical for the facility to consistently meet its maximum design flows —without being over -designed. Our experience has shown that the best results come from considering filtration rate, solids loading, available head loss, and media size, layering and depth, and then modeling these parameters with our pilot plant. Using this information, we can design your filtration system(s) that allows your operators to push the plant(s) during maximum demand periods without undue stress or compromised water quality. Plant Layout - Filter Backwash Water Handling and Disposal Our engineers understand the relationship between filtration and filter backwash systems. While one system filters water, the other processes spent backwash water. When the next filter cell requires backwashing, the handling system must be ready to receive and process the spent water, or the plant's capacity will be diminished. Our experience has taught us how to make sure the systems work hand -in - hand for optimal capacity. We will work with City staff to review the levels of backwash water processing, from simple retention tanks to more efficient lamella plate settlers, to a complete zero -liquid -discharge (no sanitary sewer discharge of process water) facility similar to the one we designed for Wisconsin Rapids, Wisconsin. Plant Layout - Clearwell and High Service Pump Analyses Using the new Ramsey hydraulic model, SEH Water System Specialist Chad Katzenberger will simulate operations from the proposed treatment plant to establish potential clearwell and high service pump capacities. By varying the distribution system demands over time through computer simulation, our engineers will be able to predict the operation of the facility's high service pumps. Once the distribution system's response is determined, a potential clearwell can be sized to allow the high service pumps to operate to their fullest capacity without overrunning the combined capacity of the wells and clearwell (for gravity filter alternatives). Plant Layout - Plant Design Versatility In addition to the versatility in pumping discussed above, Ramsey's water treatment facility should be conceived and designed with the flexibility to add treatment processes, either upstream or downstream, of the proposed filtration process to accommodate future requirements, whether they be emerging contaminants or switching source waters to include a different groundwater aquifer or even surface water. SEH brings extensive experience designing facilities for arsenic, radium, radon, TTHM precursor removal, volatile organic compound (VOC) stripping, softening, surface water treatment, alternate disinfection, and corrosion control for lead and copper reduction that are inclusive of upstream and downstream designs. Plant Layout - Electrical Power and SCADA Analyses The feasibility study will address the major electrical issues including power distribution, stand-by generator power, and 8 CENTRALIZED WATER TREATMENT FACILITY PROPOSAL