Septic permit rules and requirements in New Mexico
In New Mexico, the state issues the septic permit itself. It comes from the Onsite Wastewater Bureau, Environmental Health Bureau, New Mexico Environment Department. The smallest tank allowed is 1,000 gallons. 20.7.3.401 NMAC — Permitting; General Requirements · checked 2026-09-12
Onsite Wastewater Bureau
Writes the rules
checked 2026-09-23
The state
Issues the permit
checked 2026-09-12
Who issues a septic permit in New Mexico
The state issues the permit itself, through the Onsite Wastewater Bureau, Environmental Health Bureau, New Mexico Environment Department.
The rule requires a permit before anyone builds or changes a system. You apply at the local field office, so the state grants the permit, not a county.
20.7.3.401 NMAC — Permitting; General Requirements · checked 2026-09-12
The office's phone number is 1-800-219-6157.
This toll-free number reaches onsite wastewater program staff. Each district field office also lists its own direct line.
New Mexico Environment Department — Onsite Wastewater Bureau Contacts · checked 2026-09-23
The office publishes its own page on this: New Mexico Environment Department — Onsite Wastewater Bureau.
The page's own canonical tag names this address as its official link.
New Mexico Environment Department — Onsite Wastewater Bureau · checked 2026-09-23
What state law requires
Does New Mexico require a septic permit?
New Mexico requires a permit to build or change a septic system.
The state's rule for modify covers a design change or a swap of the tank or field.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
Does New Mexico require a percolation test?
New Mexico requires a soil evaluation, not a percolation test, before it issues a permit.
A test hole shows the soil depth and texture under the field. The state sizes the field from that profile.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
The minimum septic tank size New Mexico allows.
1,000 gallons.
Applies to a home with two or three bedrooms.
A one-bedroom home needs a smaller tank. A bigger home needs a bigger one.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
How far the drainfield must sit from a well in New Mexico.
100 feet.
Applies to a disposal field or a seepage pit, measured to a private well.
A septic tank needs less room from a well. A public well needs more room.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
How far a system must sit from the property line in New Mexico.
5 feet.
Applies to a septic tank or a disposal field, measured to a property line.
A seepage pit needs a little more room.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
Does New Mexico require an inspection when a home is sold?
The seller must have the system evaluated before the sale.
A qualified evaluator checks the tank, the field and the setbacks. The buyer gets a copy of the report.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
Must the installer be licensed in New Mexico?
New Mexico licenses installers who build, repair or change a system.
The state's construction industries division issues the credential. A trained homeowner may install a system at their own home.
New Mexico Administrative Code, Title 20, Chapter 7, Part 3 · checked 2026-09-23
New Mexico counties on this site
We have not published a New Mexico county page yet. A county earns a page when we hold facts unique to it. Until then this page is the answer for every county in the state.
Telling us your county is how we decide which one to build next.
Sources
State records only. Each figure above has a government source and a checked-on date. County figures live on the county pages.
Verify before you act. Septic rules are set locally and they change. Check anything here with the Onsite Wastewater Bureau before you spend money on it.