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 (IDAPA 58.01.02) 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

De minimis Heat Additions

58-0102-1803

  04/11/19

04/15/19

(DEQ submittal letter)

 This revision allows de minimis additions of heat in waters that exceed applicable temperature criteria.  401 This rule docket was promulgated so that the existing rule, which continues to be effective for CWA purposes, remains in the current Idaho Administrative Code until EPA approves the rule revisions.  Pending

Update Selenium Criteria for Aquatic Life

 

58-0102-1701

  03/28/18

08/24/18

(DEQ submittal letter)		 Updated selenium criteria for aquatic life.

210.01

287		 This rule docket was promulgated so that the existing rule, which continues to be effective for CWA purposes, remains in the current Idaho Administrative Code until EPA approves the rule revisions. Pending
Update Copper Criteria for Aquatic Life

 

58-0102-1502		 03/28/18

01/08/19

(DEQ submittal letter)

 Updated copper criteria for aquatic life.

210.01

210.02

210.03		 The current Idaho Administrative Code applies.

Approved on 05/02/19

(EPA approval letter)

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 added in docket 58-0102-1501:  Use Attainability)

102

The current Idaho Administrative Code applies.

Approved on 08/23/18

(EPA approval letter)

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 updated in docket 58-0102-1401: 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 revised in docket 58-0102-1201:  Harmonic Mean)

070.08

210.01

210.03

210.04

210.05

400.06

The current Idaho Administrative Code applies.

Approved on 04/04/19 (EPA approval letter)

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).

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.

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

(DEQ 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

(DEQ submittal letter)


05/29/03

(DEQ submittal letter)

 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

05/29/03

(DEQ submittal letter)

 

 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

  

 

 

1995

 

 

 
1999

 

 

 
06/21/10

(DEQ 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 2015, 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. Neither EPA nor the state of Idaho has promulgated replacement criteria.
  210.01

10 µg/L continues to be the CWA effective arsenic criterion for both exposure through fish consumption only and exposure through drinking water+fish consumption

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

16-0102-9801
No action taken

58-0102-0801 Approved on 07/07/10 (EPA approval letter)

EPA's 2010 approval of 58-0102-0801  was remanded back to EPA

Consent Decree, NWEA v EPA  (06/07/16)

58-0102-0801

16-0102-9801

Disapproved on 09/15/16

 (EPA disapproval letter)

10/31/17  DEQ letter in response to EPA’s disapproval

April 2018 DEQ initiated rulemaking

58-0102-1801

Rulemaking deadline extended

Unopposed Motion to Modify Consent Decree, NWEA v EPA (motion granted on 6/5/18)

Variance for Page Wastewater Treatment Facility

 

58-0102-0002

  03/30/01

 05/29/03

(DEQ submittal letter)

 This revision grants a variance to the South Fork Coeur d’Alene River Sewer District (Page Wastewater Treatment Facility) from meeting water quality standards for ammonia, chlorine, cadmium, lead, and zinc discharged to the West Page Swamp.

260.02.a.

260.02.b.		 EPA disapproved the variance; therefore, Subsections 260.02.a. and b. are not effective for CWA purposes.

Disapproved on 5/7/10

(EPA disapproval letter) 

 


Staff Contacts

Water Quality Standards Lead
Vacant
DEQ State Office
Water Quality Division
1410 N. Hilton
Boise, ID 83706
(208) 373-0502