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/e~CASE # ~ AUTHORIZE CONSTRUCTION OF WELL NO. 4 By: Steven Jankowski, City Engineer Background: With the addition of Well No. 3, the water utility will have more than doubled the volume of water it can deliver from its two existing wells. In addition, an agreement with the City of Anoka allows the utility to purchase another 1.0 million gallons per day to augment its well production. However, the continued rapid growth of the utility warrants still additional well development. It is common practice for a water utility to provide a combination of water supply and storage such that the utility can meet its peak day demand with its largest single source out of service. This is known as firm well capacity. Table 1 illustrates the utility supply capacity and the systems firm well capacity with each source out of service. In the summer of 1996, the utility experienced its peak water use day with a demand of 2.6 million gallons on August 13, 1996. Observing Table 2, it can be seen that over the last six years, the increases in annual consumption have ranged from 12 to 71 percent. Based upon these past trends, I would expect a peak 1997 summer demand somewhere in the range of 20 to 60 percent higher than last summer, or a peak summer demand of 3.12 to 4.16 million gallons per day. Under the lower growth scenario, the loss of Well No. 1 or Well No. 3 would place the utility in the position of being unable to meet its peak demand day, while under the higher growth projection, the loss of any source would lead to this situation. The need for an additional well was anticipated when the contract documents were prepared for Well No. 3. A price of the drilling of Well No. 4 was set up as a separate schedule. The low bid contractor, Alberg Well has a contract price of $81,455 for this work. However, the authorization to proceed on this portion of the contract has not been issued. It is the project engineer's opinion that this is a very competitive price, as is evidenced by the bid tabulation. The engineer has also consulted with geohydrologists who have concluded that a similarly sized well located to the north, west, or south, would not cause a directional change in groundwater flow from the landfill and, that a well spaced approximately 1,000 feet from Welt No. 3 would not interfere with its production capacity. The estimated cost for a functional, producing Well No. 4 would be as follows: Well No. 4 $81,455 Pump, Vault, Controls 133,200 Connecting Watermain 36,000 Subtotal: 250,655 Overhead ~25% 62,663 TOTAL: $313,318 It is proposed that Well No. 4 be sited on the Menkveld property, approximately 1,000 feet due west of Well No. 3. The City is already negotiating with Mr. Menkveld for the purchase of this property, and has a right of entry for siting a well. Access would be provided by the future