Current through Reg. 50, No. 13; March 28, 2025
(a) Aquifer restoration. Groundwater in the production zone within the production area must be restored when mining is complete. Each Class III permit or production area authorization shall contain a description of the method for determining that groundwater has been restored in the production zone within the production area. Restoration must be achieved for all values in the restoration table of all parameters in the suite established in accordance with the requirements of §
331.104(b) of this title (relating to Establishment of Baseline and Control Parameters for Excursion Detection).
(1) Restoration table. Each permit or production area authorization shall contain a restoration table for all parameters in the suite established in accordance with the requirements of §
331.104(b) of this title. The restoration value for each parameter listed in the restoration table cannot exceed the maximum value for the respective parameter in the permit range table required under §
331.82(e)(7) of this title (relating to Construction Requirements). A restoration table value for a parameter shall be established by:
(A) the mean concentration or value for that parameter based on all measurements from groundwater samples collected from baseline wells prior to mining activities; or
(B) a statistical analysis of baseline well information proposed by the owner or operator and approved by the executive director that demonstrates that the restoration table value is representative of baseline quality.
(2) Achievement of restoration. Achievement of restoration shall be determined using one of the following methods:
(A) when all mean concentration values from groundwater samples from all baseline wells for a restoration parameter are equal to or below (or, in the case of pH, within an established range) the restoration table value for that parameter, then restoration for that parameter will be assumed to have occurred. Complete restoration will be assumed to have occurred when mean concentration values from all samples from all baseline wells for all restoration parameters are equal to or below (or, in the case of pH, within an established range) each respective restoration table value; or
(B) a statistical analysis of information from groundwater samples from baseline wells proposed by the owner or operator and approved by the executive director that demonstrates that the groundwater quality is representative of the restoration table values.
(b) Mining completion. When the mining of a permit or production area is completed, the permittee shall notify the appropriate commission regional office and the executive director and shall proceed to reestablish groundwater quality in the affected permit or production area aquifers in accordance with the requirements of subsection (a) of this section. Restoration efforts shall begin as soon as practicable but no later than 30 days after mining is completed in a particular production area. The executive director, subject to commission approval, may grant a variance from the 30-day period for good cause shown.
(c) Timetable. Aquifer restoration, for each permit or production area, shall be accomplished in accordance with the timetable specified in the currently approved mine plan, unless otherwise authorized by the commission. Authorization for expansion of mining into new production areas may be contingent upon achieving restoration progress in previously mined production areas within the schedule set forth in the mine plan. The commission may amend the permit to allow an extension of the time to complete restoration after considering the following factors:
(1) efforts made to achieve restoration by the original date in the mine plan;
(2) technology available to restore groundwater for particular parameters;
(3) the ability of existing technology to restore groundwater to baseline quality in the area;
(4) the cost of achieving restoration by a particular method;
(5) the amount of water which would be used or has been used to achieve restoration;
(6) the need to make use of the affected aquifer; and
(7) complaints from persons affected by the permitted activity.
(d) Reports. Beginning six months after the date of initiation of restoration of a permit or production area, as defined in the mine plan, and until receiving written acknowledgment from the executive director that restoration for the production areas has been accomplished, the operator shall provide to the executive director semi-annual restoration progress reports. This report shall contain the following information:
(1) all analytical data generated to monitor restoration progress for certain parameters, as approved by the executive director, during the previous six months;
(2) graphs of analysis for each restoration parameter for each baseline well or for each restoration parameter that has been amended in accordance with subsection (g) of this section;
(3) the volume of fluids injected and produced;
(4) the volume of fluids disposed;
(5) water level measurements for all baseline and monitor wells, and for any other wells being monitored;
(6) a potentiometric map for the area of the production area authorization, based on the most recent water level measurements; and
(7) a summary of the progress achieved towards aquifer restoration.
(e) Restoration table values achieved. When the permittee determines that constituents in the aquifer have been restored to the values in the Restoration Table, the restoration shall be demonstrated by stability sampling in accordance with subsection (f) of this section.
(f) Stability sampling. The permittee shall obtain stability samples and complete an analysis for all parameters listed in the restoration table from all production area baseline wells. Stability sampling may commence 60 days after cessation of restoration operations. Stability samples shall be conducted at a minimum of 30-day intervals for a minimum of three sample sets and reported to the executive director. The permittee shall notify the executive director at least two weeks in advance of sample dates to provide the opportunity for splitting samples and for selecting additional wells for sampling, if desired. To ensure water quality has stabilized, a period of one calendar year must elapse between cessation of restoration operations and the final set of stability samples. Upon acknowledgment in writing by the executive director confirming achievement of final restoration, the permittee shall accomplish closure of the area in accordance with §
331.86 of this title (relating to Closure).
(g) Amendment of restoration table or range table values. After an appropriate effort has been made to achieve restoration in accordance with the requirements of subsection (a) of this section, the permittee may cease restoration operations, reduce bleed and request that the restoration table be amended. With the request for amendment of the restoration table values, the permittee shall submit stability sampling results in accordance with subsection (f) of this section. The permittee shall notify the executive director of his or her intent to cease restoration operations and reduce the bleed 30 days prior to implementing these steps. If any restoration table value for any parameter listed in the restoration table will exceed the maximum value for the respective parameter in the permit range table, the permittee must submit an application for a major amendment of the permit range table.
(1) In determining whether the restoration table or range table should be amended, the commission will consider the following items addressed in the request:
(A) uses for which the groundwater in the production area was suitable at baseline water quality levels;
(B) actual existing use of groundwater in the production area prior to and during mining;
(C) potential future use of groundwater of baseline quality and of proposed restoration quality;
(D) the effort made by the permittee to restore the groundwater to baseline;
(E) technology available to restore groundwater for particular parameters;
(F) the ability of existing technology to restore groundwater to baseline quality in the area under consideration;
(G) the cost of further restoration efforts;
(H) the consumption of groundwater resources during further restoration; and
(I) the harmful effects of levels of particular parameter.
(2) The commission may amend the restoration table or range table if it finds that:
(A) reasonable restoration efforts have been undertaken, giving consideration to the factors listed in paragraph (1) of this subsection;
(B) the values for the parameters describing water quality have stabilized for a period of one year;
(C) the formation water present in the exempted portion of the aquifer would be suitable for any use to which it was reasonably suited prior to mining; and
(D) further restoration efforts would consume energy, water, or other natural resources of the state without providing a corresponding benefit to the state.
(3) If the restoration table is amended, stability sampling shall be repeated and conducted as described in subsection (f) of this section, except that only the parameters that were amended in accordance with this subsection will be sampled and a period of two calendar years must elapse between cessation of restoration operations and the final set of stability samples unless the permittee can demonstrate through modeling or other means that a period of less than two years is appropriate for a demonstration of stability.
(4) If the request for an amendment of the restoration table or range table values is not granted, the permittee shall restart restoration efforts.
