Protecting Public Health and the Environment.

EPA Actions on Proposed Standards

Water quality standards adopted and submitted to EPA since May 30, 2000, are not effective for Clean Water Act (CWA) purposes until EPA approves them (see 40 CFR 131.21). This is known as the Alaska Rule.

Several sections of Idaho's water quality standards are under EPA review, and until these are acted upon, their use in CWA programs, such as National Pollutant Discharge Elimination System (NPDES) permits or total maximum daily loads (TMDLs), will not be approved by EPA. In addition, two sections have been disapproved by EPA. In either case—EPA inaction or disapproval—prior rules remain in effect for CWA programs. This is problematic as the state rules will not reflect this situation.

For rule dockets adopted after 2010, DEQ submittal and EPA review documents are available on the DEQ Rulemakings webpage.

Subject Matter
Docket Number		 Effective Date of State Rule Date of Submittal to EPA Summary Affected Sections Effective for CWA Purposes Status of EPA Review

Designation and Revision of Beneficial Uses (Use Attainability Analysis)

58-0102-1501		 03/25/16 12/30/16 Added language that is consistent with the federal regulations for designating and revising uses assigned to waterbodies, providing basis for guidance on the use designation/revision process.

010 (definition:  Use Attainability)

102

 The previous standards published in 2015 Idaho Administrative Code continue to apply. Pending

Mixing Zone Policy

58-0102-1401

  04/11/15  12/22/16 Updated DEQ’s Mixing Zone Policy to take into account modern tools for evaluating mixing, lessons learned from years of implementation, and to provide greater clarity for DEQ and the regulated community.

010 (definitions: Bioaccumulative Pollutants, Thermal Shock, and Zone of Initial Dilution)

060		 The previous standards published in 2014 Idaho Administrative Code continue to apply.  Pending

Update Idaho’s Human Health Criteria

 


58-0102-0503


58-0102-1201

  

 

 

 

04/11/06

 

03/25/16		  

 

 

 

07/07/06

 

12/13/16

58-0102-0503
Updated 167 human health criteria for 88 compounds.

58-0102-1201
Updated human health criteria for 104 toxic substances (10 of which are new), plus an additional fish-plus-water criterion for copper based on the drinking water maximum contaminant level (MCL). There are 208 revised or new criteria, consisting of 94 revised and 10 new criteria based on exposure to toxic substances from the consumption of fish and ingestion of water plus an additional fish-plus-water criterion for copper, and 94 revised and 10 new criteria based on exposure to toxic substances from the consumption of fish alone. In addition, although new input values were used, the values for the antimony fish only criterion and the bromoform fish-plus-water criterion did not change; these are counted as revised criteria. With this revision, Idaho will have updated all of its human health criteria except those for arsenic, methylmercury, and asbestos.

010 (definition:  Harmonic Mean)

070.08

210.01

210.03

210.04

210.05

400.06
  • 210.01

The previous human health criteria published in 2005 Idaho Administrative Code continue to apply.  These criteria are listed in Numeric Criteria for Toxic Substances (2005).

  • 210.05.b.i

The previous human health criteria based on fish consumption rate of 6.5 g/day published in 2005 Idaho Administrative Code continue to apply.

  • 010 (definition: Harmonic Mean)
  • 070.08
  • 210.03
  • 210.04
  • 210.05.b.ii
  • 400.06

The previous standards published in 2015 Idaho Administrative Code continue to apply.

58-0102-0503 Disapproved on 05/10/12

(EPA disapproval letter)

 

On 08/06/12, DEQ notified EPA of its intention to initiate a negotiated rulemaking to revise the human health criteria for toxic pollutants (DEQ response letter).

See
58-0102-1201

 

58-0102-1201
Review pending

Reinstatement of Use Designations for Eight Boise Tributaries

58-0102-0101
Revised use designations for Boise River tributaries

58-0102-1103
Reinstated disapproved aquatic life use designations

 

 

 

 

03/15/02

 

 

 

03/29/12

 

 

 

 

03/18/02

 

 

 

06/08/12

58-0102-0101
Revised use designations for Boise River tributaries

58-0102-1103
Reinstated use designations for eight Boise River tributaries to address EPA’s November 29, 2004 disapproval.

140.12

278

The previous standards published in 2003 Idaho Administrative Code continue to apply.

58-0102-0101 Aquatic life use designations disapproved on 11/29/04 (EPA disapproval letter)

 

 

58-0102-1103
Review pending

Hells Canyon Site-Specific Salmonid Spawning Criterion for Temperature

 

58-0102-1102

  03/29/12  06/08/12 Modified the existing site-specific temperature criterion to protect fall Chinook spawning below Hell's Canyon Dam by providing for a two week transition in temperatures from October 23 through November 6.

130.01

286		 The previous criterion published in 2005 Idaho Administrative Code continues to apply.  Pending

Thermal Treatment Requirements

 

58-0102-1101

06/30/11
(temporary rule)

03/29/12
(final rule)

07/20/11

 

08/07/12		 Removed the numeric limits on point source induced changes in receiving water temperature.  401.01 The previous treatment requirements published in 2011 Idaho Administrative Code continue to apply.  Pending

Mercury/Aquatic Life

 

58-0102-0302

  04/06/05

08/08/05

(EPA submittal letter)

 In 2005, Idaho adopted EPA's recommended methylmercury fish tissue criterion for protection of human health. The decision was made to remove the old tissue-based aquatic life criteria and rely on the fish tissue criterion to provide protection for aquatic life as well as human health. Thus, published Idaho WQS do not have mercury water column criteria for the protection of aquatic life. While EPA approved Idaho's adoption of the fish tissue criterion in September 2005, it had withheld judgment on Idaho's removal of aquatic life criteria.  210.01 The water column criteria for total recoverable mercury published in 2004 Idaho Administrative Code continue to apply.

Disapproved on 12/12/08

(EPA disapproval letter)

Seasonal Cold Water Use and Temperature Criteria

 

16-0102-9704
Seasonal cold water use and temperature criteria adopted

 

58-0102-0002
Temperature criteria for seasonal cold water use revised

  

 

 

 

 

04/05/00

 

 

03/30/01

 

 

 

 


04/26/00

(EPA submittal letter)


05/29/03

 Idaho first adopted seasonal cold water use and temperature criteria in April 2000. In March 2001, Idaho revised its temperature criteria for the seasonal cold water use.  250.03  

Although the seasonal cold water use and temperature criteria adopted in 2000 have not been acted on by EPA, they were adopted by Idaho and submitted to EPA prior to May 30, 2000. Therefore, the seasonal cold water use and temperature criteria published in 2000 Idaho Administrative Code continue to apply.

  Pending

Bull Trout Temperature Criterion

 

58-0102-0002

  03/30/01  2001 Idaho first adopted Bull Trout temperature criteria in 1998. These criteria were revised in 2001 and submitted to EPA for approval. EPA has not taken action and so the Bull Trout temperature criterion effective for CWA purposes is the 1997 federally promulgated temperature criterion of 10 ºC for 7-day average maximum daily temperatures from June through September for waters specified in the federal rule (see 40 CFR 131.33).  250.02.g.ii

Bull Trout temperature criterion effective for CWA purposes is the 1997 federally promulgated temperature criterion of 10 ºC for 7-day average maximum daily temperatures from June through September for waters specified in the federal rule (see 40 CFR 131.33).

 

However, a few waters identified in Governor Batt’s 1996 Bull Trout Conservation Plan are not listed in 40 CFR 131.33. For these waters, the 1998 criteria published in 1998 Idaho Administrative Code continue to apply.

 Pending

Arsenic Human Health Criteria

 

16-0102-9501
6.2 µg/L
0.02 µg/L
adopted

 

16-0102-9801
50 µg/L
adopted

 

58-0102-0801
10 µg/L
adopted

  

 

 

03/08/95

 

 

 
12/01/97 (temporary rule)

03/19/99

 
03/29/10

  

 

 

1996

 

 

 
1999

 

 

 
06/21/10

(EPA submittal letter)
  • In 2008, Idaho adopted 10 µg/L as its CWA arsenic criterion for both exposure through fish consumption only and exposure through drinking water+fish consumption, choosing the SDWA MCL due to concerns about background levels that exceed EPA’s 304(a) criteria. EPA approved this action in 2010.
  • In June 2016, Northwest Environmental Advocates challenged EPA’s 2010 approval. Court remanded action back to EPA.
  • On 09/15/16 EPA disapproved Idaho’s adoption of 10 µg/L.
  • Until new criteria are adopted, EPA will use criteria of 6.2 µg/L for exposure through fish consumption only and 0.02 µg/L for exposure through both drinking water + consumption of fish in its NPDES permitting actions. These are the previously approved criteria, and will be used as an interpretation of Idaho’s narrative criterion for toxics. 
  210.01 The previous criteria published in 1996 Idaho Administrative Code continue to apply (Subsections 250.01.c, 250.02.a.iv, 250.03.a.i).

16-0102-9501 Approved on 06/25/96

 

16-0102-9801
No action taken

 

58-0102-0801 Approved on 07/07/10

 

NWEA v. EPA 07/07/10 approval of 58-0102-1801  was remanded back to EPA

 

58-0102-0801

16-0102-9801

Disapproved on 09/15/16

 (EPA disapproval letter)

 


Staff Contacts

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

More Information

Idaho's Water Quality Standards (IDAPA 58.01.02)