Idaho

Department of
Environmental Quality

EPA Actions on Proposed Standards

Water quality standards adopted and submitted 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.

Proposed Standards Awaiting EPA Action

2014

Water Quality Limited Waters and TMDLs – Section 055

Temporary rule submitted to EPA on July 8, 2014 (docket 58-0102-1301 – final rule effective April 11, 2015), this revision addresses the treatment of water bodies that do not support designated beneficial uses. This revision is consistent with changes in the Idaho Code and other sections of the water quality standards that have been adopted since the adoption of IDAPA 58.01.02.055. Until EPA approves this change, the previous standards continue to apply and are effective for federal Clean Water Act purposes.

055. WATER QUALITY LIMITED WATERS AND TMDLS.

01. After Determining That Water Body Does Not Support Use. After determining that a water body does not fully support designated or existing beneficial uses in accordance with Section 054, the Department, in consultation with the applicable basin and watershed advisory groups, shall evaluate whether the application of required pollution controls to sources of pollution affecting the impaired water body would restore the water body to full support status. This evaluation may include the following: (03-18-11)

a. Identification of significant sources of pollution affecting the water body by past and present activities; (03-20-97)

b. Determination of whether the application of required or cost-effective interim pollution control strategies to the identified sources of pollution would restore the water body to full support status within a reasonable period of time; (03-20-97)

c. Consultation with appropriate basin and watershed advisory groups, designated agencies and landowners to determine the feasibility of, and assurance that required or cost-effective interim pollution control strategies can be effectively applied to the sources of pollution to achieve full support status within a reasonable period of time; (03-20-97)

d. If pollution control strategies are applied as set forth in this Section, the Department shall subsequently monitor the water body to determine whether application of such pollution controls were successful in restoring the water body to full support status. (03-20-97)

02. Water Bodies Not Fully Supporting Beneficial Uses. After following the process identified in Subsection 055.01, water bodies not fully supporting designated or existing beneficial uses and not meeting applicable water quality standards despite the application of required pollution controls shall be identified by the Department as water quality limited water bodies, and shall require the development of TMDLs or other equivalent processes, as described under Section 303(d)(1) of the Clean Water Act. A list of water quality limited water bodies shall be published periodically by the Department in accordance with Section 303(d) of the Clean Water Act and be subject to public review prior to submission to EPA for approval. Informational TMDLs may be developed for water bodies fully supporting beneficial uses as described under Section 303(d)(3) of the Clean Water Act, however, they will not be subject to the provisions of this Section. 0(3-18-11)

03. Priority of TMDL Development. The priority of TMDL development for water quality limited water bodies identified in Subsection 055.02 shall be determined by the Director in consultation with the Basin Advisory Groups as described in Sections 39‑3601, et seq., Idaho Code, depending upon the severity of pollution and the uses of the water body, including those of unique ecological significance. Water bodies identified as a high priority through this process will be the first to be targeted for development of a TMDL or equivalent process. (03-18-11)

04. High Priority Provisions. Until a TMDL or equivalent process is completed for a high priority water quality limited water body, new or increased discharge of pollutants which have caused the water quality limited listing may be allowed if interim changes, such as pollutant trading, or some other approach for the pollutant(s) of concern are implemented and the total load remains constant or decreases within the watershed. Interim changes shall maximize the use of cost effective measures to cap or decrease controllable human-caused discharges from point and nonpoint sources. Once the TMDL or equivalent process is completed, any new or increased discharge of causative pollutants will be allowed only if consistent with the approved TMDL. Nothing in this section shall be interpreted as requiring best management practices for agricultural operations which are not adopted on a voluntary basis. (03-20-97)

05. Medium and Low Priority Provisions. Until TMDLs or equivalent processes are developed for water quality limited water bodies identified as medium or low priority, the Department shall require interim changes in permitted discharges from point sources and best management practices for nonpoint sources deemed necessary to prohibit further impairment of the designated or existing beneficial uses. Nothing in this section shall be interpreted as requiring best management practices for agricultural operations which are not adopted on a voluntary basis. (03-20-97)

a. In determining the necessity for interim changes to existing activities and limitations upon proposed activities, the Department, in consultation with basin and watershed advisory groups, shall evaluate the water quality impacts caused by past regulated and unregulated activities in the affected watershed.(03-20-97)

b. Consideration of interim changes shall maximize the use of cost-effective and timely measures to ensure no further impairment of designated or existing uses. (03-20-97)

06. Pollutant Trading. Development of TMDLs or equivalent processes or interim changes under these rules may include pollutant trading with the goal of restoring water quality limited water bodies to compliance with water quality standards. (03-20-97)

07. Idaho Agriculture Pollution Abatement Plan. Use of best management practices by agricultural activities is strongly encouraged in high, medium and low priority watersheds. The Idaho Agriculture Pollution Abatement Plan is the source for best management practices for the control of nonpoint sources of pollution for agriculture. (03-20-97)

2012

Reinstatement of Use Designations for Eight Boise River Tributaries – Sections 140 and 278

Final rule submitted to EPA on June 8, 2012 (docket 58-0102-1103 effective March 29, 2012), this revision reinstates use designations for eight Boise River tributaries to address EPA’s November 29, 2004 disapproval. Until EPA approves this change, the previous standards continue to apply and are effective for federal Clean Water Act purposes.

140. SOUTHWEST IDAHO BASIN.

Surface waters found within the Southwest basin total nineteen (19) subbasins and are designated as follows: (04-5-00)

12. Lower Boise Subbasin. The Lower Boise Subbasin, HUC 17050114, is comprised of seventeen (17) water body units.

Unit	Waters	Aquatic Life	Recreation	Other
SW-3b	Indian Creek Reservoir to split between New York Canal and historic creek bed	MOD	SCR
SW-3c	Indian Creek Reservoir	WARM	PCR
SW-3d	Indian Creek - source to Indian Creek Reservoir	SC	SCR
SW-6	Mason Creek - New York Canal to mouth	MOD	SCR
SW-7	Fifteenmile Creek - Miller Canal to mouth	MOD	SCR
SW-8	Tenmile Creek - Blacks Creek Reservoir Dam to Miller Canal	MOD	SCR
SW-10	Fivemile Creek - source to Miller Canal	MOD	SCR
SW-17	Sand Hollow Creek - source to mouth	MOD	SCR

(03-15-02)

278. LOWER BOISE RIVER SUBBASIN, HUC 17050114 SUBSECTION 140.12.

01. Boise River, SW-1 and SW-5 -- Salmonid Spawning and Dissolved Oxygen. The waters of the Boise River from Veterans State Park to its mouth will have dissolved oxygen concentrations of six (6) mg/l or seventy-five percent (75%) of saturation, whichever is greater, during the spawning period of salmonid fishes inhabiting those waters. (03-15-02)

02. Indian Creek, SW-3b, Mason Creek, SW-6, and Sand Hollow Creek, SW-17 -- Modified Aquatic Life Use. All numeric criteria applicable to the seasonal cold water aquatic life use apply with the exception of dissolved oxygen. Dissolved oxygen concentrations are to exceed four (4) mg/l at all times. (03-15-02)

03. Fifteenmile Creek, SW-7; Tenmile Creek, SW-8, and Five Mile Creek, SW-10 -- Modified Aquatic Life Use. All numeric criteria applicable to the seasonal cold water aquatic life use apply. (03-15-02)

04. Boise River, SW-5 and SW-11a -- Copper and Lead Aquatic Life Criteria. The water-effect ratio (WER) values used in the equations in Subsection 210.02 for calculating copper and lead CMC and CCC values shall be two and five hundred seventy-eight thousandths (2.578) for dissolved copper and two and forty-nine thousandths (2.049) for lead. These site-specific criteria shall apply to the Boise River from the Lander St. wastewater outfall to where the channels of the Boise River become fully mixed downstream of Eagle Island. (05-3-03)

Hells Canyon Site-Specific Salmonid Spawning Criterion for Temperature

Submitted to EPA on June 8, 2012 (docket 58-0102-1102), this water quality standard revision modified the existing site-specific temperature criterion to protect fall Chinook Salmon spawning below Hells Canyon Dam by providing for a two-week transition in temperatures from October 23 through November 6. Until EPA approves this change, the previous criterion continues to apply:

286. SNAKE RIVER, SUBSECTION 130.01, HUC 17060101, UNIT S1, S2, AND S3; SITE-SPECIFIC CRITERIA FOR WATER TEMPERATURE. A maximum weekly maximum temperature of thirteen degrees C (13C) to protect fall chinook spawning and incubation applies from October 23rd through April 15th in the Snake River from Hell’s Canyon Dam to the Salmon River.

Thermal Treatment Requirements

Submitted to EPA as a temporary rule on July 20, 2011, and as a final rule on August 7, 2012 (docket 58-0102-1101), this water quality standard revision removed the numeric limits on point source induced changes in receiving water temperature. Until EPA approves this change, the previous treatment requirements continue to apply:

401. POINT SOURCE WASTEWATER TREATMENT REQUIREMENTS. Unless more stringent limitations are necessary to meet the applicable requirements of Sections 200 through 300, or unless specific exemptions are made pursuant to Subsection 080.02, wastewaters discharged into surface waters of the state must have the following characteristics:

01. Temperature. The wastewater must not affect the receiving water outside the mixing zone so that:

a. The temperature of the receiving water or of downstream waters will interfere with designated beneficial uses.

b. Daily and seasonal temperature cycles characteristic of the water body are not maintained.

c. If the water is designated for warm water aquatic life, the induced variation is more than plus two (+2) degrees C.

d. If the water is designated for cold water aquatic life, seasonal cold water aquatic life, or salmonid spawning, the induced variation is more than plus one (+1) degree C.

e. If temperature criteria for the designated aquatic life use are exceeded in the receiving waters upstream of the discharge due to natural background conditions, then Subsections 401.01.c. and 401.01.d. do not apply and instead wastewater must not raise the receiving water temperatures by more than three tenths (0.3) degrees C.

2001

Seasonal Cold Temperature Criterion

Idaho first adopted temperature criteria for the seasonal cold beneficial use (IDAPA 58.01.02.250.03) in April 2000. In 2001, Idaho revised its temperature criteria for the seasonal cold beneficial use (docket 58-0102-0002). Although the criteria adopted in 2000 have not been acted on by EPA, they were adopted by Idaho and submitted to EPA prior to May 30. Therefore, the older 2000 seasonal cold temperature criteria are effective for CWA purposes:

250.03.b Water temperatures of 27 degrees Celsius or less as a daily maximum with a daily average of no greater than twenty-four degrees Celsius.

 

Bull Trout Temperature Criterion

Idaho first adopted Bull Trout temperature criteria in 1998. These criteria were revised in 2001 (docket 58-0102-0002) 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).

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 following 1998 criteria (IDAPA 58.01.02.250.02.e) are effective:

e. Bull Trout Temperature Criteria. Water temperatures for the waters identified under Subsection 250.02.e.i shall not exceed twelve degree Celsius (12 C) daily average during June, July and August for juvenile bull trout rearing and nine degrees Celsius (9C) daily average during September and October for bull trout spawning. For the purposes of measuring these criteria, the daily average shall be generated from a recording device with a minimum of six (6) evenly spaced measurements in a twenty-four (24) hour period. (3-23-98)

i. The bull trout temperature criteria shall apply to all tributary waters, not including fifth (5^th)order main stem rivers, located within areas above fourteen hundred (1400) meters elevation south of the Salmon River basin – Clearwater River basin divide, and above six hundred ( 600) meters elevation north of the Salmon River basin-Clearwater River basin divide, in the fifty-nine (59) Key Watersheds listed in Table 6, Appendix F of Governor Batt's State of Idaho Bull Trout Conservation Plan, 1996, or as designated under Sections 110 through 160 of this rule. (3-23-98)

ii. Exceeding the bull trout temperature criteria will not be considered a water quality standards violation when the air temperature exceeds the ninetieth (90th) percentile of the seven (7) day average daily maximum air temperatures for the warmest seven (7) day period of the year. (3-23-98)

iii. No thermal discharges will be permitted to the waters described under Subsection 250.02.e.i, unless socially and economically justified as determined by the Department, and then only if the resultant increase in stream temperature is less than five-tenths degrees Celsius (0.5C). (3-23-98)

 

Proposed Standards Disapproved by EPA

Toxics

Mercury—Aquatic Life

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 water quality standards 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 withheld judgment on Idaho's removal of aquatic life criteria. On December 12, 2008, EPA disapproved Idaho's removal of the old aquatic life criteria (EPA disapproval letter). The water column criteria for total recoverable mercury summarized in the table below are effective for CWA purposes (IDAPA 58.01.02.210.01, 2004).

Compound	Chemical Abstract Service Number	Aquatic Life
		CMCa (µg/L)	CCCb (µg/L)
Mercury	7439976	2.1	0.012

Note: micrograms per liter (µg/L)
^a Criterion Maximum Concentration (CMC) (i.e., acute criterion)
^b Criterion Continuous Concentration (CCC) (i.e., chronic criterion)

Various Compounds—Human Health

Idaho also updated 167 human health criteria for 88 chemicals in 2006. On May 10, 2012, EPA disapproved Idaho’s 2006 update of 167 human health criteria for toxic substances and the use of 17.5 grams per day as a fish consumption rate for calculating human health criteria (EPA disapproval letter). This action was based on EPA’s judgment that the fish consumption rate used in criteria derivation was not adequately protective of all Idahoans. As a result of this action, the following human health criteria remain in effect:

1. The older criteria published in the 2005 version of IDAPA 58.01.02.210.01 continue to apply. Numeric Criteria for Toxic Substances (2005)

2. The fish consumption rate of 6.5 grams per day published in the 2005 version of IDAPA 58.01.02.210.05.b.i. continues to apply:

   When numeric criteria for the protection of human health are not identified in these rules for toxic substances, quantifiable criteria may be derived by the Department from the most recent recommended criteria defined in EPA's Integrated Risk Information System (IRIS). When using EPA recommended criteria to derive water quality criteria to protect human health, a fish consumption rate of six point five (6.5) grams/day, a water ingestion rate of two (2) liters/day and a cancer risk level of 10^-6 shall be utilized.

On August 6, 2012, DEQ notified EPA of its intention to initiate a negotiated rulemaking to revise the human health criteria for toxic pollutants (DEQ response letter). See rulemaking Docket 58-0102-1201.