15A NCAC 02C .0224 GEOTHERMAL HEATING/COOLING WATER RETURN WELLS
(a) Geothermal Heating/Cooling Water Return Wells reinject groundwater used to provide heating or cooling for structures. These wells may be approved by the Director only if the temperature of the injection fluid is not in excess of 30 degrees Fahrenheit above or below the naturally occurring temperature of the receiving groundwater. This includes wells using a geothermal fluid source. All Geothermal Heating/Cooling Water Return Wells require a permit.
(b) Permit Applications. In addition to the permit requirements set forth in Rule .0211 of this Section, an application shall be submitted, in duplicate, to the Director on forms furnished by the Director and shall include the following:
(1) the well owner's name, address, telephone number, email address (if available), and status as a federal, state, private, public, or other activity. If the well operator is different from the owner then the same information shall be provided for the well operator.
(2) the physical address of the location of the well site if different than the well owner's mailing address;
(3) a description of the injection activities proposed by the applicant;
(4) a scaled, site-specific map showing at a minimum, the following:
(A) any water supply well and surface water body; septic system including drainfield, waste application area, and repair area; and any other potential sources of contamination listed under Rule .0107 of this Subchapter within 250 feet of the proposed injection well(s);
(B) property boundaries within 250 feet of the parcel on which the proposed wells are located; and
(C) an arrow orienting the site to one of the cardinal directions;
(5) the proposed average and maximum daily injection rate, volume, pressure, temperature, and quantity of fluid to be injected;
(6) plans and specifications of the surface and subsurface construction details of the system including a schematic of the injection and source well(s) construction;
(7) the heating/cooling system installation contractor's name, address, email address (if available), and telephone number; and
(8) such other information as deemed necessary by the Director for the protection of human health and the environment.
(c) Permit Renewals. Application for permit renewal shall be made at least 120 days prior to the expiration date of the permit.
(d) Well Construction.
(1) The water supply well shall be constructed in accordance with the requirements of Rule .0107 of this Subchapter.
(2) If a separate injection well is used then it shall also be constructed in accordance with the requirements of Rule .0107 of this Subchapter except that the entire length of the casing shall be grouted from the top of the gravel pack to the land surface in such a way that there is no interconnection of aquifers or zones having differences in water quality that would result in degradation of any aquifer or zone.
(3) For open-end wells, the casing shall be grouted from the bottom of the casing to the land surface in such a way that there is no interconnection of aquifers or zones having differences in water quality that would result in degradation of any aquifer or zone.
(4) The injection well system shall be constructed such that a sampling tap or other collection equipment approved by the Director provides a functional source of water when the system is operational. Such equipment shall provide the means to collect a water sample immediately after emerging from the water supply well and immediately prior to injection into the return well.
(e) Operation and Maintenance.
(1) Pressure at the well head shall be limited to a maximum which will ensure that the pressure in the injection zone does not initiate new fractures or propagate existing fractures in the injection zone, initiate fractures in the confining zone, or cause the migration of injected or formation fluids outside the injection zone or area.
(2) Injection between the outermost casing and the well borehole is prohibited.
(3) Monitoring of the operating processes shall be provided for by the well owner, as well as protection against damage during construction and use.
(f) Monitoring and Reporting.
(1) Monitoring of any well may be required by the Director as necessary to demonstrate adequate protection of waters of the state to the level of applicable groundwater standards.
(2) The well owner shall retain copies of records of any site maps showing the location of the injection wells, and any testing, calibration, or monitoring information done on-site. Upon sale or transfer of the property, the owner shall give a copy of these records to the new property owner(s).
(3) The permittee shall record the number and location of the wells with the register of deeds in the county in which the facility is located.
(4) A record of the construction, abandonment, or repairs of the injection well shall be submitted to the Director within 30 days of completion of the specified activities.
History Note: Authority G.S. 87‑87; 87‑88; 87‑90; 87‑94; 87‑95; 89E-13; 89E-18; 143‑211; 143‑214.2(b); 143-215.1A; 143‑215.3(a)(1); 143‑215.3(c); 150B-19(4); 40 CFR Part 144.52(a)(7); 40 CFR Part 145.11(a)(20);
Eff. May 1, 2012.