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Septic Registry

North Carolina septic installer grade levels, explained

North Carolina does not simply certify septic installers. It grades them, and the grade decides what your contractor may legally put in the ground. Hiring the wrong grade is the one mistake here that stops a job dead.

Two grades, and only two

Since 1 January 2025 North Carolina has had two installer grades. Holders of the old Grade Level I were moved into Grade Level II, and Grade Level III holders into Grade Level IV.

Grade Level II covers single tank and multiple tank conventional gravity systems, and grease traps. This is the ordinary case: a tank, a distribution box, and a drain field that works on gravity alone.

Grade Level IV covers everything in Grade Level II and then the harder half of the trade — dual pumps or dual siphons, low-pressure dispersal, drip dispersal, flow equalisation, systems needing groundwater lowering with a pump, multiple off-site systems, industrial process wastewater, residential wastewater treatment systems, TS-I and TS-II systems, reuse systems and any pretreatment component. Grade Level IV also has no gallons-per-day ceiling.

A Grade Level IV certification requires at least two years at Grade Level II first, and six hours of continuing education a year against Grade Level II’s three.

Why this matters before you sign anything

Most homeowners never need to know this, because most repairs are conventional. It matters in exactly one situation, and it is an expensive one: your soil or your lot forces an engineered system.

If your site needs a pump — because the drain field is uphill of the tank, or the water table is high, or the soil will not take a conventional field — then the permit will specify something a Grade Level II installer may not install. A contractor who quotes you anyway either subcontracts it or cannot finish. Both are worth knowing on the day of the quote rather than the day of the dig.

Of the 4,425 companies on the board’s list, 1,315 have at least one Grade Level IV certified person and 2,968 hold Grade Level II only. Every North Carolina listing here shows which.

The board certifies people, not companies

This is the detail that confuses everyone. North Carolina certifies the individual, and the board’s published list names the company that individual works for. So a company’s real capability is the sum of its certified staff — a firm with one Grade Level IV installer can do Grade Level IV work while that person is there.

Ask which certified person will actually be on your job, and check that name against the board’s list. Company pages here show how many certified people the board records and at what grades, for that reason.

Inspector certification is separate

The board also certifies inspectors, and it is a distinct credential from the installer grade. 1,051 people on the current list hold it. If you are buying a house and need someone to assess an existing system, that is the certification to look for — certified inspectors by county.

Certification is annual, and expires 31 December

North Carolina certifications run to 31 December and renew annually with continuing education. A certification listed in this year’s file is not proof of a current one next January, which is why every listing here carries the date the board published it.

Common questions

What is the difference between Grade Level II and Grade Level IV?
Grade Level II covers single and multiple tank conventional gravity systems and grease traps. Grade Level IV covers all of that plus dual pumps or siphons, low-pressure and drip dispersal, groundwater lowering, pretreatment and reuse systems, and systems with no daily flow limit. If your permit calls for anything pumped or engineered, you need a Grade Level IV installer.
What happened to Grade Levels I and III?
North Carolina consolidated the four grades into two from 1 January 2025. Existing Grade Level I holders were moved into Grade Level II and Grade Level III holders into Grade Level IV. You may still see the old grades on older paperwork.
Is a certified inspector the same as a certified installer?
No. Inspector certification is a separate credential. Someone can hold both, and many do — this site marks it on the listing where the board records it — but an installer certification alone does not permit inspection work.
How do I check my installer's grade?
Every North Carolina listing here shows the grade the board recorded, taken from the NCOWCICB certified list published 2026-08-21. The board publishes the full list itself, and your county environmental health office will also know who is certified locally.

Sources

Last reviewed August 2026. General information about how these licensing systems work, not legal or engineering advice. Tell us if something is out of date.