Idaho Water Quality Standards
Regional Water Quality Standards Information
WQS Home
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Recent Actions and Request for Comments in Idaho
Idaho Water Quality Standards
Idaho WQS Effective for Clean Water Act Purposes
Guidance for Pacific Northwest State and Tribal Temperature Water Quality Standards
Idaho Waterbody and Designated Use Data
Enviromapper for Idaho
Contacts
Idaho Department of Environmental Quality | ![](https://webarchive.library.unt.edu/eot2008/20081109201645im_/http://yosemite.epa.gov/icons/ecblank.gif) | U.S. Environmental Protection Agency, Region 10 |
1410 North Hilton
Boise, ID 83706
Fax (208) 373-0576
Don Essig, dessig@deq.state.id.us,
(208) 373-0119 | ![](https://webarchive.library.unt.edu/eot2008/20081109201645im_/http://yosemite.epa.gov/icons/ecblank.gif) | 1200 Sixth Ave, Suite 900
Seattle, WA 98101
Fax (206) 553-0165
Lisa Macchio, macchio.lisa@epa.gov
(206) 553-1834 |
Recent Actions and Request for Comments in Idaho
EPA approves updated numeric criteria for toxic substances of arsenic, cadmium, chromium, nickel, antimony, zinc, and new methyl mercury fish tissue human health criteria contained in Idaho’s Water Quality Standards and Wastewater Treatment Requirements on September 30.
Idaho also developed Implementation Guidance
for its Mercury Water Quality Criteria.
EPA denies a request for a variance to water quality standards for the discharge of metals from the Hecla Lucky Friday Mine on March 8. EPA makes available the following documents: decision document (pdf file, 97 Kb, 30 pages) and
EPA's response to comments received during the public comment period between September 1-30, 2004 (pdf file, 134 Kb 32 pages)
EPA approved Idaho's revised natural condition provisions of their water quality standards on July 20, 2004.
EPA has granted water quality standards variances to the municipalities of Smelterville, Mullan and Page, Idaho. Smelterville and Page received variances for cadmium, zinc, and lead, and Mullan received variances for cadmium and zinc.
What are Water Quality Standards (WQS)?
Water quality standards are the foundation of the water quality-based control program mandated by the Clean Water Act. Water Quality Standards define the goals for a waterbody by designating its uses, setting criteria to protect those uses, and establishing provisions to protect water quality from pollutants.
A water quality standard consists of four basic elements:
- designated uses of the water body (e.g., recreation, water supply, aquatic life, agriculture),
- water quality criteria to protect designated uses (numeric pollutant concentrations and narrative requirements),
- an antidegradation policy to maintain and protect existing uses and high quality waters, and
- general policies addressing implementation issues (e.g., low flows, variances, mixing zones).