Summary of New Mexico's Water Reuse Guideline or Regulation for Centralized Non-potable Reuse

This page is part of the EPA’s REUSExplorer tool, which summarizes the different state level regulations or guidelines for water reuse for a variety of sources and end-uses.
The source water for this summary is Treated Municipal Wastewater.

On this page:

• Technical basis
• Applications of centralized non-potable reuse approved for use in New Mexico
• Water reuse category/type
• Additional context and definitions
• Centralized non-potable reuse specifications (table)
• Upcoming state law or policy
• References
• Disclaimer

---

This page is a summary of the state’s water reuse law or policy and is provided for informational purposes only. Please always refer to the state for the most accurate and updated information. 

In New Mexico, centralized non-potable reuse centralized non-potable reuse The use of recycled water for centralized non-potable reuse where the water does not derive from the same site where it is to be reused. Can include, but is not limited to, toilet flushing, dust control, soil compaction, fire protection, commercial laundries, vehicle washing, street cleaning, snowmaking, and other similar uses. Excludes on-site non-potable water reuse and the use of recycled water for agriculture or landscaping. applications include street cleaning, snow making and concrete mixing, among others. The source of water (treated municipal wastewater) treated municipal wastewater Treated wastewater effluent discharged from a centralized wastewater treatment plant of any size. Other terms referring to this source of water include domestic wastewater, treated wastewater effluent, reclaimed water, and treated sewage. is specified by the state as domestic wastewater. The write-up uses state terms when discussing sources or uses of water that may differ from the Regulations and End-Use Specifications Explorer's (REUSExplorer's) terms.

Technical basis

The New Mexico Environment Department (NMED) provides guidance for above ground reuse of reclaimed domestic wastewater to “ensure protection of public health and the environment” (NMED, 2007). All applicable provisions of the Clean Water Act (CWA) (33 U.S.C. §§ 1251 et seq.), including its implementing regulations, must be met in addition to any state water quality standards. Class 1B and Class 2 reclaimed wastewaters are approved for centralized non-potable reuse applications including, but not limited to, street cleaning, snow making, toilet flushing and dust control. Both classes of reclaimed wastewater have the same specifications for BOD and TSS (30 mg/L monthly average and 45 mg/L single sample maximum, respectively) and require regular monitoring of total residual chlorine or UV transmissivity. The specification for fecal coliform is stricter in Class 1B reclaimed water (100 organisms/100 mL monthly average and 200 organisms/100 mL single sample maximum) than Class 2 reclaimed water (200 organisms/100 mL monthly average and 400 organisms/100 mL single sample maximum). The technical basis for the removal of pathogens and chemicals is not explicitly specified.

Applications of centralized non-potable reuse approved for use in New Mexico

NMED (2007) defines the following approved centralized non-potable reuse applications:

• Street cleaning, snow making, toilet flushing (Class 1B)
• Concrete mixing, dust control and soil compaction (Class 2)

Water reuse category/type

The various classes of reclaimed water treatment are defined by their respective treatment requirements and applicable performance standards. The respective treatment requirements are briefly summarized for centralized non-potable reuse applications. 

• Class 1B reclaimed wastewater is suitable for uses in which public exposure is likely. It requires a minimum of conventional secondary wastewater treatment plus disinfection and a fecal coliform specification of 100 organisms/100 mL monthly average and 200 organisms/100 mL single sample maximum.
• Class 2 reclaimed wastewater is suitable for purposes in which public access and exposure is restricted. It requires a minimum of conventional secondary wastewater treatment plus disinfection and a fecal coliform specification of 200 organisms/100 mL monthly average and 400 organisms/100 mL single sample maximum. 

Additional context and definitions

In New Mexico, reclaimed water is defined as “domestic wastewater that has been treated to the specified levels for the defined uses set forth in this guidance document and other applicable local, state, or federal regulations” (NMED, 2007). Domestic wastewater is defined as “wastewater containing human excreta and water-carried waste from typical residential plumbing fixtures and activities, including but not limited to wastes from toilets, sinks, bath fixtures, clothes or dishwashing machines and floor drains” (NMED, 2007).

New Mexico requires all municipal reclaimed wastewater piping, valves and outlets to be colored purple to differentiate it from piping or fixtures used for potable or other water (NMED, 2007). Reclaimed wastewater systems should have no indirect or direct cross connections with potable water systems. Signs in English and Spanish stating “NOTICE – THIS AREA IS IRRIGATED WITH RECLAIMED WASTEWATER – DO NOT DRINK” must be placed at the entrance to areas receiving reclaimed wastewater and other locations where public access may occur. 

Centralized non-potable reuse specifications

Summary of New Mexico's Centralized Non-potable Reuse Specifications

Source = NMED (2007)

^* Information about sampling and monitoring requirements such as frequency, site and quantification methods not specifically listed in the table was not explicitly specified in the state-specific regulations.  

^a A “major” WWTP has a maximum design capacity of 1 million gallons or more per day. A “minor” WWTP has a maximum design capacity of less than 1 million gallons per day.

^bE. coli may be used in place of fecal coliform as an indicator organism once an equivalency has been established.
 

Upcoming state law or policy

NMED has proposed supplemental requirements for water reuse (20.6.8 NMAC) including produced water and will accept public comment through December 1, 2023. 

References:

Clean Water Act, 33 U.S.C. §§ 1251 et seq.

New Mexico Environment Department (NMED). 2007. NMED Ground Water Quality Bureau Guidance: Above Ground Use of Reclaimed Domestic Wastewater.

---

Disclaimers

Please contact us at [email protected] if the information on this page needs updating or if this state is updating or planning to update its laws and policies and we have not included that information on the news page.