Implementation

This rule establishes minimum requirements to maintain and protect groundwater quality. This rule applies to all activities with the potential to degrade groundwater quality. (7-1-26) 01. Groundwater Quality Standards. The numerical and narrative standards in Sections 200 and 301 identify minimum levels of protection for groundwater quality and will be used as a basis for: (7-1-26) a. Evaluating or comparing groundwater quality when developing or modifying best available methods, best management practices, or best practical methods; (7-1-26) b. Identifying permit conditions; (3-24-22) c. Establishing cleanup levels; and (3-24-22) d. Determining appropriate actions when groundwater quality standards are exceeded. (7-1-26) 02. Aquifer Categorization. Aquifers of the state will be categorized based on vulnerability of the groundwater, existing and projected future beneficial uses of the groundwater, existing water quality, and social and economic considerations. There will be three (3) aquifer categories, Sensitive Resource, General Resource, and Other Resource, to provide different levels of protection. The level of protection required for each category and application of standards to these categories are shown in Table I. (7-1-26) a. All aquifers where there are activities with the potential to degrade groundwater quality are categorized in Section 300. Those aquifers where no activities with the potential to degrade groundwater quality are occurring will remain uncategorized until such activities are commenced. If no action is taken to categorize an aquifer when an activity(ies) with the potential to degrade groundwater quality is initiated, the aquifer will automatically be categorized as General Resource. (7-1-26) b. Categorization will be considered when an activity with the potential to degrade groundwater Table I. Level of Protection and Application of Standards to Aquifer Categories Category Level of Protection Application of Standards Sensitive Resource Apply best management practices and best available meth- ods. This category provides the highest level of groundwater protection. May apply stricter standards than in Section 200. General Resource Apply best management practices and best practical meth- ods to the maximum extent practical. Apply numerical and narrative standards in Section 200. Other Resource Apply best management practices and best practical meth- ods to the maximum extent practical. May apply less strict standards than in Section 200. IDAHO ADMINISTRATIVE CODE IDAPA 58.01.11 Department of Environmental Quality Groundwater Quality Rule Section 200 Page 6 quality is proposed over an aquifer or portion of an aquifer that presently has no such activities and, based on the criteria in Section 350, the aquifer may be most appropriately categorized as Sensitive Resource or Other Resource. (7-1-26) c. Recategorization will be considered when information on vulnerability of the groundwater, existing and projected future beneficial uses of the groundwater, existing quality of the groundwater and social and economic considerations, in conjunction with one (1) or more of the criteria in Section 350, demonstrates that the aquifer or portion of an aquifer may be more appropriate in another category. (7-1-26) 03. Groundwater-Surface Water Interconnection. The beneficial uses of interconnected surface water will be recognized when evaluating groundwater quality protection. The implementation of water quality programs ensure that the quality of groundwater that discharges to surface water does not impair the identified beneficial uses of the surface water and that surface water infiltration does not impair beneficial uses of groundwater. (7-1-26) 04. Interagency Coordination. The Department will coordinate with other federal, state, and local agencies to pursue interagency agreements when necessary to ensure implementation of this rule for activities with the potential to degrade groundwater quality. (7-1-26) 151. -- 199. (RESERVED)