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7 <br />7.1 <br />7.2 <br />softened water. However, residents that are concerned about hard water are likely already <br />softening their water with a home softener. <br />As of the preparation of this report, the Study was still in draft form. When the Study is complete, <br />it will be available to the public on the MCES website. The citation for the report is: Metropolitan <br />Council. 2020. Northwest Metro Area Regional Water Supply System Study. Prepared by Short <br />Elliott Hendrickson Inc. Metropolitan Council: Saint Paul. <br />Because it has been demonstrated that Ramsey should have sufficient groundwater available to <br />meet future dernands, a surface water treatment plant is not recon-irnended at this time_ A <br />potential Ramsey groundwater treatment plant will be located close enough to the Mississippi <br />River that it could be converted to a surface water treatment plant in the future if it became <br />necessaiy. It is recommended that surface water features be designed into a potential water <br />treatment plant. The additional cost of the surface water features is approximately $250,000. <br />Water Treatment <br />To remove manganese, iron, or hardness from Ramsey's drinking water, a water treatment <br />facility could be constructed. <br />Current and Future Treatment Needs <br />Many of Ramsey's wells are high in manganese, which has necessitated a solution to reduce the <br />levels due to its health concerns. Ramsey's water is also high in iron and hardness. Ramsey's <br />water otherwise meets all of the primary and aesthetic drinking water standards. <br />Manganese and iron can be removed with oxidation and sand filtration as discussed in the pilot <br />study in Appendix E. Hardness removal options are discussed in Section 7.5. <br />Future treatment requirements will depend upon the class of contaminant being treated, Volatile <br />chemicals can typically be removed using an aerator (i.e. gasoline constituents, trichloroethylene <br />[TOE], radon, hydrogen sulfide, etc.). Some organic chemical may be removed using granular <br />activated carbon (potential taste and odor causing contaminants). It may also be possible to add <br />chemical feed systems to remove new contaminants using sand filters (i.e. arsenic, radium). If it <br />is not possible to remove the contaminants by volatilization, carbon filtration, or sand filtration, <br />membrane filters could be necessary (i.e. reverse osmosis). It should be noted that sand <br />filtration is typically required ahead of membrane filters because iron and manganese causes <br />fouling on the membranes. <br />In addition to potential future contaminants, a water treatment plant could be designed with <br />features that would allow it to be converted to a surface water treatment plant in the future. One <br />of these feature would be filter -to -waste piping and valves. Filter -to -waste piping is required for <br />surface water treatment, but not generally used with groundwater treatment. <br />Ultimately, having a treatment facility that is flexible and can be retrofitted to meet new potential <br />requirements is very important. <br />Treatment Capacity <br />As discussed in Chapter 4, the maximum day demand ranged from 4.1 to 5.5. MGD in the last 10 <br />years. While the overall maximum day water demand has been flat in the last 10 years, the <br />FEASIBILITY STUDY -DRAFT RAMSY 154354 <br />Page 25 <br />