Water: Regulatory Information
Withdrawal of Nutrient Standards for the State of Arizona
- Why Is EPA seeking removal now?
- What will remain after removal of the Federal Standards?
- Will Arizona's standards protect designated uses?
- Will there be an additional burden on the regulated community?
- Will it change the way National Pollution Discharge Elimination System (NPDES) permits are written in Arizona?
- What is the result of today's action?
- How to get additional information
EPA withdrew federal water quality standards for nutrients for eleven river segments in Arizona. This removal is appropriate because Arizona has adopted numeric and narrative water quality criteria along with implementation procedures that are scientifically defensible and meet the requirements of the Clean Water Act, making the promulgated Federal standards unnecessary.
In 1976, EPA found that Arizona's revisions to its water quality standards did not meet the requirements of the Clean Water Act (CWA). As required by the CWA, EPA promulgated Federal numeric nutrient criteria for total nitrates and total phosphates for eleven river segments in Arizona. The Agency also promulgated narrative water quality criteria for nutrients for all surface waters in Arizona. In June 1976, these water quality criteria became part of the applicable water quality standards for Arizona for all purposes and programs under the Clean Water Act [see 40 CFR 131.31(a)].
Subsequent to EPA's 1976 promulgation of the nutrient criteria for Arizona, the Arizona Department of Environmental Quality adopted numeric nutrient criteria for total nitrogen and total phosphorous for specific water bodies. The State also adopted narrative nutrient criteria and implementation procedures for all of its surface waters. EPA found that the State's numeric and narrative nutrient water quality criteria and the implementation procedures for the narrative criteria fully protect the designated uses of Arizona's waters and are consistent with the Clean Water Act and Federal regulations. As a result, EPA approved these adoptions. Thus, the Agency recognizes that the Federal standards for nutrients for Arizona waters are redundant and no longer necessary.
About this Regulation Removal
This removal will eliminate duplicative regulations. Dischargers complained about the resource burden for meeting both sets of requirements. They requested variances from the Arizona Department of Environmental Quality.
After this action removing the Federal criteria, the State-adopted Numeric Nutrient Standards, Narrative Nutrient Standard, Implementation Guidelines for the Narrative Nutrient Standard and Nutrient Waiver Rules will continue to apply to Arizona's waters.
Yes, Arizona's standards will be at least as protective as the Federal Standards and will have greater specificity when using the State's Implementation Guidelines. You can see letters that confirm this in the docket supporting EPA's approvals.
No. The Arizona State Water Quality Standards are already in place, and the Federal Standards apply in addition to them. Thus removing the Federal Standards will, if anything, reduce the burden of meeting duplicative requirements.
The Arizona Department of Environmental Quality will not have to issue variances to help dischargers avoid duplicative federal standards. Many numeric permit limits will be as stringent or become more stringent than they were before. A few permits may appear to be less stringent, but the limits they contain will actually be equally protective as the previous ones. In these cases, the earlier limits went beyond what was necessary to fully protect all designated uses. Arizona has NPDES permit writing authority and will implement their Arizona standards in new and renewed permits. EPA will retain oversight authority.
EPA's final rule will remove federally-promulgated nutrient water quality criteria for the State of Arizona. Arizona's numeric and narrative nutrient criteria, along with the State's implementation procedures, will then remain as the sole applicable water quality standards for Arizona.
For additional information about this rule, contact either of the following:
EPA Region 9
75 Hawthorne Street
San Francisco, CA 94105
Office of Water (4305T)
1200 Pennsylvania Ave. NW
Washington, D.C. 20460
Federal Register notice describing how to get more information and review the complete administrative record.