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2. Grandview Lift Station Capacity201 1st Avenue East, P.Q. Box 1997, Kalispell, MT 59903 —Phone (406) 758- 7720 — Fax (406) 758- 7831 www.k-alispell.com To: Mayor Pamela Kennedy &Kalispell City Council Cc: James C. Plansz, P.E., Public Works Director/City Engineer From: Paul E . Burnham, P . E . , Assistant city Engineer Date: October 27, 2008 council Meeting Re: Grandview Lift Station capacity 2002 Facility Plan r�rrrrr.�mnminn nnnninnnnninnnin� The 2002 Water, Sewer and Storm Drainage Facility Plan describes upgrades to the Grandview Lift Station. These upgrades were completed in May 2007 and included the pipe burst project, which increased the existing six-inch force main to a ten -inch force main. With this project, the pumping capacity of the Grandview Lift Station increased from approximately 260 gallons per minute (gpm) to 460 gpm. 200E Facility Plan. The 2008 Wastewater Facility Plan describes additional upgrades to the Grandview Lift Station. These upgrades include increasing the dual pumps and motors from. 20 horsepower (hp) to 30 hp, as well as replacing the interior pipe manifold system. These upgrades necessitated the addition of increased capacity in downstream gravity lines. This increased need for downstream capacity is described in the 2008 Facility Plan, and is included in the Plan's cost estimates for the Grandview Lift Station upgrades. These upgrades are currently being designed by the B loomstone engineer (Morris on- Maierle, Inc.) and will likely be completed by May 2009. The initial cost of the engineering and construction will be borne by one or more private developers. The City will then reimburse the developers With sanitary sewer impact fees collected by the City. These upgrades will increase the pumping capacity from 460 gpm to 860 gpm. Last year (August 13, 2007) the City's consultant (HDR, Inca presented the facility plan update to the City Council. In this presentation, HDR indicated that the aforementioned upgrades would be necessary to accommodate proposed growth in the northwest area of the City. Following that presentation, the Public Works Department sought to determine how much of the 460 gpm capacity was actually being used. Pump tests in October 2007 indicated peak flows of approximately 370 gpm, or roughly 80 la of the firm capacity. Pump tests up to July 2008 indicate peak flows of 416 gpm, or roughly 90% of firm capacity. The improvements to the Grandview Lift Station that will be completed by May 2009 will provide capacity for the developments that have received preliminary plat approval and approval from the Department of Environmental Quality (DEQ). Capacity for additional development will have to be obtained through additional improvements described in the 2008 Wastewater Facility Plan. HDR described these improvements to the City Council in the August 13, 2007 council meeting. These improvements are described in the 2008 Wastewater Facility Plan as the Stillwater Road Interceptor. These are shown with a 2007 capital cost of $4.6 million. During the past few months the Public works Department has reviewed plans for various developments in the northwest area of the City. These plans have included Starling Phase 1, Silverbrook Phase 1, Bloomstone Phase 1, DNRCIDEQ, and remaining portions of Spring Prairie and Hutton Ranch. The proposed upgrades to the Grandview Lift Station will bring the firm capacity to 860 gpm. This is sufficient capacity to serve these approved phases. There appears to be some excess capacity beyond that used by the developments listed above. The developer of Glacier Towne Center has applied for this capacity, and may have sufficient capacity to complete the commercial core of that development. Morrison-Maierle will likely determine final firm capacity within the next few weeks, and will answer three critical questions: First, is the firm capacity greater than the anticipated 860 gpm? Second, will there be sufficient capacity for the entire commercial core of the Glacier Towne Center development? And, third, will there be any excess capacity above that required by the Glacier Towne Center commercial core? In the Site Review Meetings of June 12, 2008 and July 17, 2008, the Public works Department raised the issue of limited capacity at the Grandview Lift Station, and reiterated what had been discussed in the August 13, 2007 council meeting, i.e., that additional development in the northwest area of the City would have to find alternate routes to convey sewage to the wastewater treatment plant. The developer and engineer from the proposed Valley Ranch development were present at the June 12, 2008 meeting. The staff report (#K-PUD-08-1, concerning the proposed Valley Ranch Development) submitted to the Planning Board and City Council on August 6, 2008 indicates: "The Kalispell Public Works Department has stated that additional off -site improvements are necessary to convey sewage from the Valley Ranch project and other development in this area to the waste water treatment plant, located approximately 5 1I2 miles south." The additional off -site improvements mentioned above refer to the Stillwater Road Interceptor, which would provide the additional capacity above that provided by the currently proposed upgrade due to be completed by May 2009. The Kalispell City Planning Board and Zoning Commission recommended to the City Council "that the valley Ranch P UD be approved subject to the 26 conditions listed in the staff report." Condition 17 of the staff report requires, "Upon submitting a preliminary plat application for each phase the developer shall provide the Public Works .Department with a plan of how sewage will be conveyed to the sewer treatment plant. The plan, once reviewed and approved by the Public Works Department, would be required to be installed prior to final plat approval."