In New Mexico, no permit is required for greywater systems when the flow is less than 250 gallons per day.
Regulatory overview:
Excerpt from New Mexico House Bill 711, passed in 2005, related to water:
...shall not require a permit for applying less than two hundred fifty gallons per day of private residential gray water originating from a residence for the resident's household gardening, composting or landscape irrigation if:
- a constructed gray water distribution system provides for overflow into the sewer system or on-site
wastewater treatment and disposal system;
- a gray water storage tank is covered to restrict access and to eliminate habitat for mosquitos or other
vectors;
- a gray water system is sited outside of a floodway;
- gray water is vertically separated at least five feet above the ground water table;
- gray water pressure piping is clearly identified as a nonpotable water conduit;
- gray water is used on the site where it is generated and does not run off the property lines;
- gray water is applied in a manner that minimizes the potential for contact with people or domestic pets;
- ponding is prohibited, application of gray water is managed to minimize standing water on the surface and to ensure that the hydraulic capacity of the soil is not exceeded;
- gray water is not sprayed;
- gray water is not discharged to a watercourse; and
- gray water use within municipalities or counties complies with all applicable municipal or county
ordinances enacted pursuant to Chapter 3, Article 53 NMSA 1978;
More details:
The full version of the New Mexico greywater regulation can be found here.