Committee approves pesticide rule changes, separates chemigation licensing and describes groundwater sampling program

The Idaho Senate Agricultural Affairs Committee approved two related rule dockets that rewrite pesticide groundwater protection requirements and separate chemigation licensing from federal categories, both measures the Idaho State Department of Agriculture said will simplify licensing and preserve groundwater protections.

The changes, presented by Brian Slabaugh, administrator of the Division of Agricultural Resources at the Idaho State Department of Agriculture, implement a state-specific chemigation applicator license after the Legislature passed House Bill 549 in 2024 and remove duplicative language that the department said already exists in statute for pesticide management and groundwater monitoring.

The rewrite of the pesticide management plan rule, the department said, removes duplicative or descriptive language that already appears in Title 22, Chapter 34 of Idaho Code and reorganizes definitions and abbreviations to improve clarity. The separate chemigation rule creates a standalone chemigation applicator license and multiple pathways for obtaining it — exam, department-approved training, or on-site demonstration — rather than strictly following federal licensing categories.

"The legislation amended how licenses for chemigation applicators are categorized by separating those licenses from federal categories," Brian Slabaugh, Administrator, Division of Agricultural Resources, said. "This rule proposes a simplified process for acquiring and maintaining those licenses."

The department said the change responds to industry requests and makes it easier for people who chemigate only fertilizer or who do not fit a federal license category to be licensed by the state without adding new public burdens. Slabaugh noted the department has partnered with the University of Idaho on a chemigation training module and is developing additional training and on-site verification options so operators who can demonstrate competence are eligible for the state chemigation license without taking a formal exam.

Director Chanel Tiwall, Idaho State Department of Agriculture, framed the department's approach to rulemaking as conversational and customer-focused, and defended the department's decision to use multiple pathways to licensing. "The ZBR process is only as good as an agency chooses to make it," Tiwall said. "If someone calls and complains with something, we want to give them the most thorough answer we can."

Committee members pressed presenters for operational detail. Slabaugh described the department's voluntary groundwater monitoring program: over the last five years the department has collected about 1,300 water samples and analyzes roughly 89 active pesticide ingredients; in a typical year the department works with as many as about 300 private well owners. "We test for a group of about 89 active ingredients," Slabaugh said. "Over the last 5 years we have about 1300 water samples that we have analyzed for pesticides."

Senators asked how sampling is initiated and how frequently testing occurs. Slabaugh said sampling is done in partnership with well owners; the department cannot compel sampling of private wells. When contaminants are found at elevated levels the department may increase sampling frequency and work with affected well owners on quarterly monitoring or other response steps to better understand sources and groundwater movement. He said samples are analyzed at a pesticide residue laboratory in Twin Falls and that well owners and the public are notified when detections occur and in annual reports.

Several portions of the presented pesticide rules were characterized as "duplicative" of statute and removed from the rule text; the department said enforcement authority remains in statute and that the edits were intended to make the rule more readable rather than to reduce protections. The committee was told there were two negotiated rulemaking meetings and no public comment submitted on the pending pesticide rule dockets.

Both dockets were approved by voice vote with no roll call tally recorded in the transcript. The committee approved docket 0203012401 (rules governing pesticide management plans for groundwater protection) and docket 0203032402 (rules governing pesticide and chemigation use and application) by voice vote.

The rules and the discussion included clarifications about who can be licensed and how the department verifies competence for chemigation systems, and emphasized that some statute-based requirements remain in code even when language is removed from the rule text. The department said it intends to continue using an advisory committee as circumstances require and to continue annual groundwater testing and reporting.

Looking ahead, Slabaugh and Director Tiwall said the pesticide rule set will remain an "evolution" and the department expects to continue adjusting apprentice categories and training options in response to industry hiring challenges. Slabaugh told the committee that the department's next steps include expanding training pathways and continuing partnerships for on-site verification and development of additional Spanish-language training materials.

Ending note: the committee approved the two pesticide rule dockets during the same meeting and the department said it will continue to refine training and licensing options while maintaining groundwater monitoring and enforcement authorities under Idaho statute.