Protecting Public Health and the Environment.

Water Quality: Docket No. 58-0102-1802 - Proposed Rule

Rulemaking initiated for revision of recreational use criteria and adoption of aquatic life criteria for three toxics.

Public Comment Opportunities | History

Status of Rulemaking

Proposed rule open for public comment September 5 through October 5, 2018.

November 2018 Board of Environmental Quality Meeting

Rulemaking Documents Required by Idaho Administrative Procedure Act


This rulemaking has been initiated to make certain revisions identified as high priority in the 2017 Triennial Review of Idaho Water Quality Standards and to comply with federal requirements for consideration of EPA recommended (aka §304(a)) criteria (40 CFR 131.20): (1) Adopt aquatic life criteria for acrolein, carbaryl, and diazinon in accordance with EPA’s current §304(a) recommended criteria, and (2) adopt EPA’s current §304(a) recommended criteria for bacteria and clarify the definition of recreational use. 

EPA’s Recommended §304(a) Aquatic life Criteria for Acrolein, Carbaryl, and Diazinon

This rulemaking adds criteria for acrolein, carbaryl, and diazinon in Subsection 210.01. Currently, Idaho does not have aquatic life criteria for acrolein, carbaryl, and diazinon, although EPA has issued new recommended aquatic life criteria for these toxics. Acrolein is an aquatic herbicide and is known to be toxic to aquatic life, particularly amphibians and fish. In 2009, EPA added acrolein to the §304(a) list of aquatic life criteria. Carbaryl and diazinon are pesticides that are toxic to aquatic life, particularly invertebrates. EPA added diazinon to the §304(a) list of aquatic life criteria in 2005 and added carbaryl in 2012.

In order to avoid EPA promulgating federal standards for acrolein, carbaryl, and diazinon for Idaho, DEQ proposes to undertake a negotiated rulemaking to revise these aquatic life criteria in Idaho’s water quality standards. By adopting these criteria, DEQ will comply with federal requirements for consideration of EPA recommended criteria (40 CFR 131.20) and ensure that its criteria provide sufficient protection of aquatic life uses.

EPA’s §304(a) Recommended Criteria for Bacteria

This rulemaking adopts EPA’s 2012 §304(a) recommended criteria for bacteria. EPA’s 2012 §304(a) criteria includes both E. coli criteria as well as enterococci criteria; either of which would be considered protective of contact recreation. States (and dischargers) can use either criterion to demonstrate compliance with water quality standards. This rulemaking also clarifies the definition of recreational use, recognizing that waters designated for primary contact recreation (PCR) also include recreational activities associated with secondary contact recreation (SCR).

Consideration of enterococci criteria as included in EPA’s 2012 §304(a) recommendation is necessary to comply with federal requirements for consideration of EPA recommended criteria (40 CFR 131.20). Enterococci criteria are more directly related to incidences of gastrointestinal illnesses than E. coli criteria. In addition, rapid analytical techniques for enterococci are currently being developed. By adopting enterococci criteria, Idaho will be in a position to easily integrate any advances to improve sampling logistics (for example, extended holding times and field preservation to allow for monitoring and assessment of more remote waters, and rapid notification of affected swimming beaches and recreational facilities).

DEQ will also consider the adoption of statistical threshold values (STV) as criteria. The STV is a concentration that is not to be exceeded more frequently than 10% of valid samples collected in a 30-day period.

By adopting EPA’s 2012 §304(a) criteria recommendation, DEQ can meet a recommendation of the 2017 Triennial Review and meet federal requirements to consider EPA’s 2012 §304(a) recommendations while providing the same level of protection for Idaho water bodies. In addition, this allows dischargers the option to request an alternative fecal indicator bacteria for monitoring compliance with water quality standards.

Idahoans that recreate in, drink from, or fish Idaho’s surface waters and all who discharge pollutants to those same waters may be interested in commenting on this proposed rule. After consideration of public comments, DEQ intends to present the final proposal to the Board in November 2018 for adoption of a pending rule.  The rule is expected to be final and effective upon the conclusion of the 2019 legislative session if adopted by the Board and approved by the Legislature.

Effective for Clean Water Act Purposes

Water quality standards adopted and submitted to EPA since May 30, 2000, are not effective for federal Clean Water Act (CWA) purposes until EPA approves them (see 40 CFR 131.21). This is known as the Alaska Rule. This rulemaking will be promulgated so that the existing rule, which continues to be effective for CWA purposes, remains in the Idaho Administrative Code until EPA approves the rule revisions. Notations explaining the effectiveness of the rule sections are also included. Upon EPA approval, the revised rule will become effective for CWA purposes and the previous rule and notations will be deleted from the Idaho Administrative Code. Information regarding the status of EPA review will be posted at here.

Public Comment Opportunities

Submit all written comments by mail, fax or email to:

Paula Wilson
Idaho Department of Environmental Quality
1410 N. Hilton, Boise, ID 83706
Fax: (208) 373-0481,

Comment Deadline

October 5, 2018

Written Public Comments

Submitted By Date Received

Negotiated Rulemaking History

The text of the proposed rule was drafted based on discussions held and concerns raised during negotiations conducted pursuant to Idaho Code § 67-5220 and IDAPA The Notice of Negotiated Rulemaking was published in the May 2018 issue of the Idaho Administrative Bulletin, a preliminary draft rule was made available for public review on May 8, 2018, and meetings were held on May 31 and June 28, 2018. Key information was posted on the DEQ rulemaking web page and distributed to the public. Members of the public participated in the negotiated rulemaking process by attending the meetings and by submitting written comments.

All comments received during the negotiated rulemaking process were considered by DEQ when making decisions regarding development of the rule.  At the conclusion of the negotiated rulemaking process, DEQ formatted the final draft for publication as a proposed rule. The negotiated rulemaking record, which includes the negotiated rule drafts, written public comments, documents distributed during the negotiated rulemaking process, and the negotiated rulemaking summary, is available on this webpage.

Negotiated Rulemaking Meeting Schedule

No additional meetings are scheduled.

Previous Meetings

June 28, 2018 - Agenda | Sign-in Sheets
May 31, 2018Agenda | Sign-in Sheets

Draft Negotiated Rule and Meeting Presentation Documents

Draft Negotiated Rule Date Posted Date of Meeting Discussion Written Comment Deadline

Draft No. 4



DEQ is not requesting public comments on this draft. The next comment period will commence upon publication of the proposed rule in the September 5, 2018, issue of the Idaho Administrative Bulletin. The proposed rule comment deadline is October 5, 2018.

Draft No. 3

Revision of Recreation Use and Criteria and Adoption of Aquatic Life Criteria for Three Toxics -  DEQ PowerPoint Presentation













Draft No. 2
(Draft No. 2 includes revisions presented during the 5/31/18 meeting)

Revision of Recreation Use and Criteria and Adoption of Aquatic Life Criteria for Three ToxicsDEQ PowerPoint Presentation

Revision of Recreation Use and Criteria and Adoption of Aquatic Life Criteria for Three Toxics -  Discussion Paper #1








05/31/18 06/08/18
Preliminary Draft (Draft No. 1) 05/08/18 05/31/18 06/08/18

Written Public Comments

Comment Submitted By Date Received
Comment on Draft No. 3 Association of Idaho Cities (AIC) 07/30/18
Comment on Draft No. 3 Association of Idaho Cities (AIC) 07/16/18
Comment on Draft No. 2 U.S. EPA Region 10 06/05/18
Comment on Draft No. 2 Upper Snake River Tribes Foundation (USRT) 06/06/18
Comment on Draft No. 2 City of Meridian 06/07/18
Comment on Draft No. 2 Idaho Conservation League (ICL) 06/08/18
Comment on Draft No. 2 Association of Idaho Cities (AIC) 06/08/18

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Staff Contacts

Water Quality Standards Lead
Jason Pappani
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0515

Administrative Rules Coordinator
Paula Wilson
DEQ State Office
Attorney General's Office
1410 N. Hilton
Boise, ID 83706
(208) 373-0418