5A - Conditional Use Permit for the RV Resort Village at the Preserve (continued)

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MEMO April 12,2006 Page 2 of 2 While variable frequency drives(VFD's) on well pumps work well for matching varying demands on zoned irrigation systems, VFD's are difficult to control properly on a domestic water supply system where flow rates vary considerably over very short periods of time. As we discussed that is why water towers are used to meet varying instantaneous water demands (gravity is always on). Discussions with the MnDOH on other projects finds that they have seen limited success with VFD's used by developments in the metro area and some VFD's removed after to many issues. Automatic lawn irrigation systems shall not be connected to the potable water system. If the RV Resort Association wants to provide irrigation for the common areas(green space), then separate well(s),pumps and distribution system will be needed to supply irrigation water. A well house around 12' x 20' in size will be used to house the pneumatic pressure tanks, well pump electrical supply and controls. This well house would also provide some space for future treatment systems should water quality be an issue. Note that backwash from any treatment system must be reviewed before it can be discharged into the sanitary sewer system. Typically these systems are timed to backwash in the early AM hours when water usage is low so the backwash hydraulic flow is not an issue. Chemical that might be used to oxidize iron or manganese need to be reviewed to assure compatibly with wastewater treatment system operations. Typically this is not an issue but a check needs to be made. Once WSN has a design completed and ready for submittal to the MnDOH I would like to meet with you and the well driller(s) you propose to utilize for a final review.