Septic inspection when selling a house in New Mexico
1 statewide rule and 0 local rules from official sources.
General information, not legal advice. This is our summary of the official rule as we read it. The ordinance or code and the health department decide: confirm with them before you list, sign or close.
Statewide: septic system at sale
| Question | What the official text says |
|---|---|
| What is required | Non-invasive evaluation of the liquid waste system by a qualified third-party evaluator on NMED-approved form, report provided to buyer; reports sent to NMED within 15 days Source: srca.nm.gov |
| Triggered by | transfer of a property with an established on-site liquid waste system Source: srca.nm.gov |
| Deadline | prior to transfer Source: srca.nm.gov |
| Who arranges it | transferor (seller) Source: srca.nm.gov |
| How long a report is valid | evaluation not needed if a final inspection or prior transfer evaluation was done within 180 days of transfer Source: srca.nm.gov |
| Exemptions |
Source: srca.nm.gov |
| If the system fails | Owner shall remedy failed system with NMED approval; permit or variance application within 15 days of evaluation by the party who will own on day 15 Source: srca.nm.gov |
| In force since | September 1, 2013 Source: srca.nm.gov |
Checked on November 9, 2026: read on the official site.
Private wells in New Mexico
About 292,165 of New Mexico’s 2,085,109 residents (14%) got their drinking water from a private well in 2015, by the USGS estimate.
Source: USGS county water use 2015 (Dieter et al., 2018); 33 counties in the USGS table.
Where private wells (and usually septic systems) are most common
New Mexico ranks 33 of 45 states and territories by people on private wells (USGS 2015). In 3 of its 33 counties more than half of residents drink from a private well; homes there usually also treat wastewater on site, so a septic check and a well test tend to come up together at sale. The highest shares:
- Catron County: 65% of 3,456 residents on a private well
- Cibola County: 53% of 27,329 residents on a private well
- McKinley County: 53% of 76,708 residents on a private well
- Valencia County: 42% of 75,737 residents on a private well
- Union County: 40% of 4,201 residents on a private well
- Rio Arriba County: 38% of 39,465 residents on a private well
- Hidalgo County: 38% of 4,423 residents on a private well
- Harding County: 34% of 698 residents on a private well
USGS county water use 2015 (Dieter et al., 2018). The USGS table counts well users, not septic systems; no national county count of septic systems exists.
Soils for septic drain fields in New Mexico
Across the 9 counties with USDA soil survey data, 70% of rated land is “very limited” for a conventional septic drain field. Most limited: Hidalgo County (91%), Colfax County (91%), Luna County (89%). Least limited: Roosevelt County (31%), De Baca County (58%), Guadalupe County (60%).
Source: USDA NRCS Soil Survey Geographic Database (SSURGO), via Soil Data Access, rating “ENG - Septic Tank Absorption Fields”, read November 15, 2026. County-wide ratings, not a test of one lot.
How the neighbouring states compare
New Mexico has a statewide rule. Of its 5 neighbouring states, 1 has a statewide rule at sale; a buyer moving across the line may meet a different rule. From our register of official rules:
- Arizona: statewide septic system rule at sale.
- Colorado: no statewide rule; 10 local rules (counties, cities or townships).
Testing a well? See certified well-water labs and testing advice in New Mexico.
Other states: all states.