12-08-1986 Council Packet - Laserfiche WebLink

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City of ORONO RESOLUTION OF THE CITY COUNCIL NO. - --- 12.. The City Engineer contacted Roman Kanavetski, Minnesota Geological Survey, Gil Gabanski, Twin City Testing and M. Schoenberg, U.S. Geological Survey regarding concern for the depletion of the Prairie Du Chein/Jordan acquifer by random application of geothermal heating/cooling systems. Their comments were summarized by Mike Lynch as follows: "These experts indicate that one home pumping an average of 30 gpm of flow from the Prairie Du Chein/Jordan acquifer or even 100 such homes will have essentially no effect upon the acquifer. There is some concern amongst experts and regulating agencies that a concentration of "big users" may be causing a fluctuation of the groundwater level within the acquifer. One such example is the City of St. Paul water system. This system has caused a noticeable fluctuation in the level of the acquifer due to an immense quantity of groundwater withdrawal from a relatively small area. On the other hand, Townsquare in St. Paul has a geothermal system that pumps at a rate of 1200 gpm without regional depletion of the acquifer. The usage of the acquifer is currently being regulated by the DNR and the Health Department. The popularity of geothermal heating systems for residential properties has been dying out the past couple of years as there is no longer an energy credit for their use and the placement of such a system is generally not cost-effective. 13. The discharge pipe for the geothermal system will enter the lake within a protected lagoon area below the lake level at a 924.6 elevation. 14. There will be no navigational hazards created for the users of Lake Minnetonka because the discharge pipe will not extend into the main lake area. 15. Neither the velocity of the discharge nor the temperature of water discharged will have any de-icing effect on the main lake. 16. The proposed geothermal system is defined as a closed system requiring no additives, conditioners or other chemicals. The quality of the water to be discharged into the lake will not pose a pollution hazard. 17. Dr. Richard Hanson of the fresh Water Biological Institute has voiced major concern with the uncontrolled, intense, multiple uses of our groundwater reserves and strongly recommends that a national policy be formulated providing standards for groundwater uses to assure that we are not creating an irreversible crisis. In his letter of :.eptember 15, 1986, he noted that he "found it difficult for one city to have a major impact on this issue". Page 3 of 6