Agenda - Council - 06/23/1981 - Laserfiche WebLink

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Honorable Mayor and City Council City of Ramsey June 18, 19B1 Page Four in 1974, Anoka wells #4 and #6, and Andover well #1. The wells in Elk River and Anoka produced from 130D gpm to 2000 gpm during their test pumping; however, the Andover well was test pumped at a maximum rate of 900 gpm, and it can produce only about 500 gpm of water at an acceptable sand concentration. This illustrates the variability of the formations, and the difficulty involved in making precise estimates of well yield during the design process. However, based on the data from the Elk River and Anoka wells, we estimate that a well completed in the Mt. Simon formation could reasonably be expected to produce 800 gpm, with a possibility of 1000 gpm or slightly more. The well liner illustrated on the attached exhibit ends at the top of the Franc~nia, .with all lower formations open. It should be mentioned that Health Department regulations prohibit drawing water from more than one aquifer in any given well. Thus, if a well is intended to draw water from the Mt. Simon formation, the formations above the confining Eau Claire formation would have to be cased off. The well could not draw water from both the Franconia - Ironton-Galesville and the Mt. Simon formations. Below the Mt. Simon lies the Hinckley formation. The Hinckley is also predomin- antly sandstone, with a hydraulic conductivity somewhat lower than the Mt. Simon. Due to its greater depth, it is not considered economical to rely on the Hinckley as a source of water, although the Hinckley could be used to increase the capacity of a Mt. Simon Well somewhat. CONCLUSION: have reviewed the available data on geologic conditions in Ramsey in order to assess the feasibility of using wells for a municipal water supply source. Some question exists regarding this, because the sandrock formation which routinely .yields 1000 to 1500 gpm in areas south of Ramsey {the Jordan formation) is not found in Ramsey. Therefore, we have estimated the feasibility of two deeper formations; 1) the Franconia and Ironton-Galesville, and 2) the Mt. Simon. The glacial drift is fairly impermeable in Ramsey. It is considered unlikely that a significant municipal supply well could be developed in the drift. There may be areas of sand and gravel deposits, particularly along the Rum River, which would provide a sufficient quantity of water. However, such areas could only be located by test drilling and pumping. The Franconia and Ironton-Galesville formations could be reasonably expected to produce 400 to 5DO gallons per minute. These are the shallowest formations which contain water in municipal supply quantities. A well approximately 400 feet deep, located in southeastern Ramsey, would be required to tap these formations.