Surface Water Quality Bureau
Water Quality Standards

New Mexico's Water Quality Standards (WQS) define water quality goals by designating uses for rivers, streams, lakes and other surface waters, setting criteria to protect those uses, and establishing provisions to preserve water quality.

New Mexico’s Water Quality Standards, codified at 20.6.4 NMAC, define water quality goals by designating uses for rivers, streams, lakes and other surface waters, setting criteria to protect those uses, and establishing antidegradation provisions to preserve water quality. The Standards are adopted by the Water Quality Control Commission (WQCC), then approved by the United States Environmental Protection Agency (US EPA) under the federal Clean Water Act (CWA).

PROPOSED AMENDMENTS
For the Lower Dry Cimarron River and Lakes

The WQCC has granted SWQB's petition for a hearing on proposed amendments to the water quality standards. The proposed amendments would change the aquatic life use on the lower Dry Cimarron River from coldwater to coolwater, and it would add new segments establishing water quality standards for approximately 65 lakes in the Rio Grande, Pecos, Canadian, Gila, San Juan and Little Colorado Basins.   The hearing is currently scheduled to begin April 10, 2012.

PETITION

CURRENT STANDARDS
The current standards incorporate the Outstanding National Resource Waters designated in December 2010 as well as amendments adopted during the triennial review.  These standards are effective for state purposes, and they are also effective for CWA purposes as of April 18, 2011, except for the following provisions:

	20.6.4.8.A(3): antidegradation for ONRWs (EPA approval pending);
	20.6.4.9.D(3): new ONRWs in wilderness areas (EPA approval pending);
	20.6.4.10.D(1)(e): EPA did not approve this sentence in new site-specific criteria provision;
	20.6.4.13.J:  narrative turbidity (EPA did not approve this amendment);
	20.6.4.52 – salinity benchmarks for lower Pecos River (EPA approval was not requested); and
	20.6.4.900.I and J – new/revised hardness-based criteria for aluminum, cadmium and zinc (EPA approval pending).
US EPA-Approved Standards: as noted above, US EPA denied approval for some of the state’s new standards, and has yet to take action on others. This document shows the US EPA-approved standards currently in effect for CWA purposes.

OUTSTANDING NATIONAL RESOURCE WATERS
On November 30, 2010, the WQCC approved a petition designating perennial streams and lakes as well as identified wetlands in U.S. Forest Service wilderness areas as ONRWs. The newly designated waters and associated changes to the state’s Antidegradation Policy are amendments to the water quality standards and are effective for state purposes as of January 14, 2011. The WQCC’s action also amended the Antidegradation Policy Implementation Procedure applicable to point source discharges, and approved a new implementation document, Guidance for Nonpoint Source Discharges in ONRWs. EPA approval of the revised standards is pending.  The Rio Santa Barbara and the waters of the Valle Vidal were previously designated as ONRWs. See the Outstanding Waters page for additional information.

TRIENNIAL REVIEW
New Mexico held its most recent Triennial Review hearing Dec. 8-11, 2009. Based on the hearing record, the WQCC adopted numerous amendments and issued a Statement of Reasons explaining the amendments in October 2010. In a letter and Record of Decision dated April 18, 2011, EPA approved most of the provisions.  See the Triennial Review site for more information.

	Revisions to 20.6.4 NMAC in underline/strikeout format.  All amendments are approved by EPA and effective for CWA purposes except: 20.6.4.10.D(1)(e); 20.6.4.13.J (narrative turbidity); 20.6.4.52 (salinity benchmarks for lower Pecos River – the state did not desire or request EPA approval of this provision); and new/revised hardness-based criteria for aluminum, cadmium and zinc in 20.6.4.900.I and J.
	EPA's Approval Letter and Record of Decision
	WQCC's Order and Statement of Reasons for Amendment of Standards (dated October 14, 2010).

USE ATTAINABILITY ANALYSES
SWQB has prepared a UAA to support its proposal to change aquatic life use on the lower Dry Cimarron River.  SWQB has also initiated a UAA for Galisteo Creek. Information about these investigations and how to be involved is provided here. Both UAAs are reviewing the designated aquatic life uses. Part of the analysis rests on an air-water temperature correlation that NMED has developed based on average air temperatures and on long-term water temperature data collected by the SWQB from streams across the state.

TRIBAL STANDARDS
New Mexico’s Standards do not apply to waters on Native American lands. Tribes and pueblos develop and implement their own water quality standards. As with states, tribal standards are approved by the US EPA. Approximately half of New Mexico’s tribes and pueblos have US EPA-approved standards. For more information or to review any of the available online tribal and pueblo standards in New Mexico please click here.