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Hamm Sewer Request <br />February 19,1999 <br />Page 2 <br />Site Factors Limit Septic Options <br />Mr. Palmer was advised by staff that sewer might only be feasible if it could be demonstrated that <br />suitable options for septic system replacement are lacking. Site evaluation by S.P. Testing (Steve <br />Schirmers) in 1996 found a site suitable for a mound system to handle the anticipated 1500 gallons <br />per day sewage load from the existing buildings. In 1998 Schirmers found that this site had been <br />damaged by tree removal vehicles. He also noted that while an additional area may exist northeast <br />of the main house, that area is wooded and its use would eliminate the natural screening between the <br />main house and Orono Orchard Road. <br />While the Hamm property is much larger than any of the neighboring Minnetonka Bluffs prop>erties <br />sewered in 1980, its septic system options are limited by some of the same factors that forced the <br />Bluffs to be sewered. Due to the clay soils and perched water tables present, a mound system would <br />be required, and Orono's code limits the pre-existing ground slope for mounds to 6%. There are few <br />areas of the site with enough area of suitable slopes to accommodate a mound large enough to serve <br />the main house and guest houses. Exhibit B prepared by staff shows the areas potentially meeting <br />the 6% slope criteria, numbered 1 thru 7. Area 1 is the tested site damaged by tree removal. Area <br />2 is the wooded site northeast of the main house. Area 3 is a limited site due to size. Areas 4 and <br />5 are too small to accomodate a mound system. Area 6 is a wide drainageway that will be wet in <br />most seasons. Area 7 is the old clay tennis court which has been compacted through the years. <br />The information submitted does not, in staffs opinion, conclusively demonstrate that septic systems <br />are not a viable option. The submittals do demonstrate that the potential septic sites are very limited, <br />and use of certain sites may have potential negative impacts on the character of the property. These <br />same characteristics apply to any number of smaller residential properties throughout the City. <br />Zoning and Future Development <br />This site is in the RR-IB zoning district requiring a minimum lot area of 2 acres. The City has <br />historically not expanded its sewer system to accommodate new development in the rural 2-acre <br />zones, but has required such development to be served by septic systems. The City did recently <br />revise its MUSA along the Maxwell Bay lakeshore to allow new lakeshore development in the 2-acre <br />zone to be sewered. However, the development that triggered that MUSA change, was allowed only <br />the number of lots that could have been developed by actually using septic systems, i.e. the number <br />of lots was limited not only by the 2-acre standard but also by actual septic capability. <br />The relevance of this to the 18-acre Hamm site is that based on septic capability, the Hamm site has <br />extremely limited developability. With sewer, the site might accommodate as many as 7 or 8 homes <br />based on a 2-acre density. Mr. Hamm has no stated intent to develop the property at this time; his <br />goal is to provide for the existing dwellings. If the sewer request is granted. Council may wish to <br />impose conditions on future development of the property with sewer, perhaps limiting the number <br />of units to the 3 necessary for the existing buildings.