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Geothermal Rules <br />Statement of Basis and Purpose <br />exceeding 212' Fahrenheit). The Rule acknowledges the manufacturer's and system <br />designer's expertise in construction of loop fields and defers to their specifications for <br />such installation. However, the Rule does not abrogate the owner's, operator's, <br />constructor's or certified individual's responsibility to comply with all applicable <br />provisions of these Rules (e.g. materials, circulating fluids, testing, reporting, etc.). <br />To further protect the public health, ground water resource, and the environment, the <br />Rule also declares that only a certified individual may perform/supervise the <br />construction of a loop field. Therefore, any person who intends to perform/supervise the <br />construction of a Type A-CLH well must obtain certification from the State Engineer and <br />maintain the certification in accordance with the policies of the State Engineer adopted <br />for such certification. <br />To minimize the potential for creating a sink or sump where contaminants from the <br />surface can accumulate and potentially enter the ground water resource, Rule 8.4.1 <br />requires that the material used to backfill a trench or excavation constructed for the <br />installation of horizontal loops be no more permeable than the surrounding soil. It is <br />recognized that most trenches or excavations will be filled with the material removed <br />during excavation. The Rule requires that the backfill material be compacted during the <br />backfill process so that a depression will not form as a result of settling of the material <br />over time. <br />Rule 8.4.2 is specific to Type-CLH systems that utilize loops submerged in a pond or <br />lake as the material medium for heat transfer. The Rule specifies <br />construction/supervision by a certified individual and compliance with all testing <br />requirements for the loops. Paramount in the Rule is the need to take all necessary <br />precautions to prevent spillage or leakage of circulating fluids (other than clean water) <br />and the means to contain the fluid should such spill or leak occur. <br />Rule 8.5 is developed to set standards for drilling boreholes and grouting of Type A-CLV <br />geothermal wells (vertical closed -loop geoexchange systems that do not exceed a <br />depth of 2500 feet or encounter geothermal fluids with temperatures exceeding 212' <br />Fahrenheit). The Rule addresses the need to contain ground water and geothermal <br />fluids in the aquifers or hydrogeologic units in which they are encountered. The <br />provisions of the Rule and its subsections are consistent with the primary objectives of <br />these Rules: to protect the public health, ground water and geothermal resources, the <br />environment, and to prevent material injury to any valid, prior water or geothermal rights <br />or waste of the resource. <br />To facilitate the proper installation of grout material in a borehole necessary to achieve <br />a permanent grout seal, Rule 8.5.1 requires that the borehole diameter exceed the <br />composite loop dimension by at least one inch on all sides of the piping or tubing. A <br />loop must be located in the hole in such a way as to ensure that grout material fully <br />encases the loop and establishes a seal between the loop material and the borehole <br />wall. <br />M <br />