Standards For The Quality Of Fluids Injected Into Class V Wells

01. General. Injected fluids shall meet Ground Water Quality Standards for physical, biological, IDAHO ADMINISTRATIVE CODE IDAPA 37.03.03 – Rules & Minimum Standards Department of Water Resources for the Construction & Use of Injection Wells Section 055 Page 17 chemical, and radiological contaminants, and if ground water produced from adjacent points of diversion for beneficial use meets the Ground Water Quality Standards as defined in these rules, then that aquifer will be protected from unreasonable contamination and will be preserved for diversion to beneficial uses. The Director may, however, when it is deemed necessary, require specific injection wells to be constructed and operated in compliance with additional requirements, such as best management practices (BMPs), so as to protect the ground water resource from deterioration and preserve it for diversion to beneficial use. (7-1-25) 02. Waivers. A waiver of one (1) or more standards may be granted by the Director if it can be demonstrated by the applicant that the contaminants in injected fluid will not endanger a ground water source for any present or future beneficial use. (7-1-25) 03. Chemical and Radiological Contaminants in Injected Fluids. The following limits shall not be exceeded in injected fluids from a well when such fluids will or are likely to reach a USDW: (7-1-25) a. The concentration of each chemical contaminant in the injected fluids shall not exceed the concentration of each applicable contaminant in the receiving water or the ground water quality standard, whichever is less stringent; and (7-1-25) b. Radiological levels of the injected fluids shall not exceed those levels specified by the Ground Water Quality Standards. (7-1-25) 04. Biological contaminants. The following restrictions apply to injected fluids with biological contaminants included in the ground water quality standard. (7-1-25) a. Contamination of ground water produced at any point of diversion for beneficial use by injected fluids containing coliform bacteria in concentrations greater than the current ground water quality standard is prohibited; (7-1-25) b. Construction of shallow and deep injection wells, as specified by the Director, that are likely to exceed the current ground water quality standard for coliform bacteria at the point of diversion for beneficial use is prohibited; and (7-1-25) c. The Director may require the use of best management practices (BMPs) to reduce the potential concentration of coliform bacteria in the injected fluids; (7-1-25) d. The Director may require the use of water treatment technology, including ozonation and chlorination devices, sand filters, and settling pond specifications to reduce the potential concentration of coliform bacteria in injected fluids; (7-1-25) e. Ground water produced from points of diversion for beneficial use within the distances identified in Table 1. that inject fluids containing coliform bacteria in concentrations greater than the current ground water quality standard shall be subject to monitoring for bacteria by the owner/operator of the injection well. A waiver of the monitoring requirement may be granted by the Director when it can be demonstrated that injection will not result in unreasonable contamination of ground water produced from these adjacent points; (7-1-25) f. At no time shall any untreated fluid containing fecal contaminants of human origin be injected into any Class V injection well authorized under these rules. Subsurface fluid distribution systems that apply or distribute recycled water to the root-zone and regulated by IDEQ are exempt from this rule. (7-1-25) 05. Physical, Visual, and Olfactory Characteristics. The following restrictions apply to physical, visual, and olfactory characteristics of injected fluids. The temperature, color, odor, conductivity, turbidity, pH, or other characteristics of the injected fluid may not result in the receiving ground water becoming less suitable for diversion to beneficial uses, as determined by the Director. (7-1-25) 06. Injectate Standards for the Quality of Recycled Water Derived from a Municipal or Industrial Wastewater Source. (7-1-25) IDAHO ADMINISTRATIVE CODE IDAPA 37.03.03 – Rules & Minimum Standards Department of Water Resources for the Construction & Use of Injection Wells Section 057 Page 18 a. Shallow Injection Wells. The concentration of contaminants in recycled water derived from municipal or industrial wastewater sources must prevent contamination and comply with established Ground Water Quality Standards and all other applicable IDEQ rules and permitting requirements prior to injecting into a shallow injection well. (7-1-25) b. Deep Injection Wells. The concentration of contaminants in recycled water derived from municipal or industrial wastewater sources must prevent contamination and comply with established Ground Water Quality Standards and all other applicable IDEQ rules and permitting requirements prior to injecting into a deep injection well. Additionally, injected fluids must not result in the endangerment of a USDW. Recycled water quality requirements shall be determined by the Department in coordination with IDEQ during the permitting process. The background concentration of any applicable contaminant shall be determined by a statistical analysis consisting of a type and method approved by the Department. (7-1-25) 07. Standards for the Quality of Fluids Injected to Subclass 5A7 Wells (Open-Loop Heat Pump Return). (7-1-25) a. The quality of fluids injected to a Subclass 5A7 injection well shall comply with Ground Water Quality Standards or shall be equal to the quality of the ground water source passed through a heat exchange system, whichever is less stringent. (7-1-25) b. If the quality of the ground water source does not meet Ground Water Quality Standards, the injected fluids must be returned to the formation from which they were drawn. (7-1-25) c. The temperature of the injected fluids shall not impair the designated beneficial uses of the receiving ground water. (7-1-25) 056. (RESERVED)