New Mexico Register / Volume XXXVI, Issue 20 / October 21, 2025

This is an amendment to 20.6.4 NMAC, Sections 126 and 141, effective 11/8/2025.

20.6.4.126 RIO GRANDE BASIN: Perennial waters within lands managed by the U.S. department of energy (DOE) within Los Alamos National Laboratory (LANL), including but not limited to: Cañon de Valle from LANL stream gage E256 upstream to Burning Ground spring, Sandia canyon [from Sigma canyon upstream to LANL NPDES outfall 001] at Sigma canyon upstream to Sandia canyon at Bedrock Road, Pajarito canyon from 0.5 miles below Arroyo de La Delfe upstream to Homestead spring, Arroyo de la Delfe from Pajarito canyon to Kieling spring, Starmers gulch and Starmers spring and Water canyon from Area-A canyon upstream to State Route 501.

A. Designated uses: coldwater aquatic life, livestock watering, wildlife habitat and secondary contact.

B. Criteria: the use-specific numeric criteria set forth in 20.6.4.900 NMAC are applicable to the designated uses.

[20.6.4.126 NMAC - N, 5/23/2005; A, 12/1/2010; A, 4/23/2022; A, 11/8/2025]

[20.6.4.141 - 20.6.4.200 [RESERVED]]

20.6.4.141 RIO GRANDE BASIN: Sandia canyon from Sandia canyon at Bedrock Road upstream to LANL NPDES outfall 001.

A. Designated uses: coolwater aquatic life, livestock watering, wildlife habitat and secondary contact.

B. Criteria: the use-specific numeric criteria set forth in 20.6.4.900 NMAC are applicable to the designated uses, except that the following additional segment-specific criterion applies: a 6T3 temperature of 25°C (77°F).

[20.6.4.141 NMAC - N, 11/8/2025]

20.6.4.142 - 20.6.4.200 [RESERVED]