House Resources and Conservation Committee approves revised injection-well rules to preserve state primacy

Eric Bowe, Water Compliance Bureau chief and rules regulation officer for the Idaho Department of Water Resources, told the House Resources and Conservation Committee the department is proposing rewritten rules for Class 5 injection wells to ensure protection of groundwater and to preserve state primacy under the federal Safe Drinking Water Act.

The proposed rule package reorganizes several sections of the existing rule, redefines terms to align with federal code, prohibits construction of new subclass 5F1 agricultural drainage injection wells, and adds standards for the quality and use of recycled water in certain limited circumstances. The committee voted to accept the docket after in-person testimony supporting the revisions.

Nut graf: The rules are intended to keep Idaho’s program consistent with federal requirements (CFR 144.1 and the Safe Drinking Water Act), clarify technical definitions and procedures, and provide a pathway for some municipalities to use highly treated recycled water without compromising underground source drinking water (USDW) or the state’s regulatory primacy.

Bowe told the committee the pending rule redefines “endangerment” and the definition of USDW to “be in line with Federal code, specifically CFR 144.1 and section 14.22 of the Safe Drinking Water Act,” and that most reorganization changes were intended to improve readability while substantive edits were limited to select sections. He said the department published a notice of intent to negotiate the rule on April 5, 2023, hosted five public negotiating meetings over two years and received “well over 100 oral and written comments” that were considered in drafting the rule.

On prohibitions, Bowe said the department changed prior language to explicitly prohibit construction of new subclass 5F1 agricultural-waste injection wells (commonly described as agricultural drainage wells). He told the committee the subclass label is based on the source of water, not the conveyance: if water originates as agricultural runoff it is treated as 5F1 even when routed through a canal, whereas surface water diverted from a river would be categorized under a different subclass. Representative Nelson asked whether the change would effectively prohibit use of canal water for injection; Bowe replied that classification depends on the source and that the new language is “less restrictive” than earlier drafts and aligns with current practice.

Bowe also described new language in Rule 55 that limits injection of untreated fluids containing contaminants of human origin and establishes standards (Rule 55.06) for recycled water derived from municipal or industrial wastewater sources. He said the revised language exempts subsurface fluid distribution systems regulated by DEQ that distribute recycled water to the root zone.

Jason Van Gilder, public works director for the City of Middleton and a licensed professional engineer, testified in support of the rules. Van Gilder told the committee Middleton is pursuing subsurface drip irrigation to land-apply highly treated effluent and that the previous rules “did not have provisions to suitably address the possibility of using subsurface drip tape to irrigate agricultural crops with treated effluent.” He said the revised rules remove barriers that previously required Middleton to seek a waiver and added, “Updating the state's administrative rules in a way that protects our natural resources, protects our citizens, encourages innovation and adapts to new challenges while removing unnecessary bureaucracy and administrative red tape is exactly what 0 based rulemaking should be about.”

Committee members asked technical questions about class definitions, shallow vs. deep injections, and how canal flows that include return irrigation flows would be classified. Bowe and other department staff repeatedly emphasized the changes were intended to preserve state primacy for class 5 injection well regulation—IDWR acquired primacy in 1985—and to incorporate stakeholder input. Bowe said the department has not permitted a new 5F1 well since around February (year not specified in testimony) and noted existing permits are handled with injection-rate restrictions to limit impacts on domestic wells.

Representative Anderson moved to approve the docket (motion text recorded as “I move that we approve docket 370,300 and three-two 301”). The committee conducted a voice vote; the clerk announced the docket was accepted.

Ending: With the docket accepted, the committee moved to other rule dockets on its agenda.