Septic rules and requirements in Johnston County, North Carolina
Septic permits in Johnston County are issued by the Johnston County Environmental Health Department. A new system permit costs $600. USDA rates most of the soil in the county Very limited for septic absorption fields — 64.3% of the rated acres. Johnston County Environmental Health — On-Site Wastewater (Septic Systems) · checked 2026-09-23
Johnston County Environmental Health
Issues the permit
checked 2026-09-23
$600
Septic system permit
checked 2026-09-23
Very limited
USDA rating, 64.3% of rated acres
checked 2026-09-11
Who issues septic permits in Johnston County?
Johnston County Environmental Health Department, at 309 E. Market Street, Smithfield, NC 27577, 919-989-5180. It is part of county government. The state writes the rules it applies.
A department of the county. It checks each lot for a septic system. It issues or denies the permit on that check. It inspects new systems, looks into complaints, and watches large and pump systems.
Open Monday to Friday, 8:00 a.m. to 5:00 p.m., except holidays. Specialists are in the office from 8:00 to 9:30 a.m.
Johnston County Environmental Health — On-Site Wastewater (Septic Systems) · checked 2026-09-23
What does a septic permit cost in Johnston County?
$600 for a septic system permit, on the county's own schedule.
Applies to systems with a design flow of 480 gallons a day or less, the schedule's smaller tier.
In effect from July 1, 2026.
| Septic System Permit (Systems 480 Gallons or less) | $600 | a system of up to 480 gallons a day |
|---|---|---|
| Large System Design (Systems >480 Gallons) | $700 | a system of more than 480 gallons a day |
| GS 130A-335(A2)only --SL 2022-11 Permit (480 gallons or less) | $600 | a system of up to 480 gallons a day the source lists as issued under GS 130A-335(A2) only, Session Law 2022-11 |
| GS 130A-335(A2)only--SL 2022-11 Permit (>480 gallons) | $700 | a system of more than 480 gallons a day the source lists as issued under GS 130A-335(A2) only, Session Law 2022-11 |
| GS 130A-335(A2)(A5)--SL 2022-11 Permit (480 gallons or less) | $240 | a system of up to 480 gallons a day the source lists as issued under GS 130A-335(A2)(A5), Session Law 2022-11 |
| GS 130A-335(A2)(A5)--SL 2022-11 Permit (>480 gallons) | $280 | a system of more than 480 gallons a day the source lists as issued under GS 130A-335(A2)(A5), Session Law 2022-11 |
Johnston County Environmental Health Fee Schedule · checked 2026-09-23
Is the soil in Johnston County suitable for a septic system?
USDA rates most of the county Very limited for septic absorption fields — 64.3% of the rated acres. A rating describes the ground, not a parcel. The county's site evaluation decides each lot.
USDA NRCS Soil Data Access (SSURGO) · checked 2026-09-11
What Johnston County sets itself
The state writes the code. Johnston County adds the rules below. They are what makes this page differ from the North Carolina requirements.
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$600
Applies to systems with a design flow of 480 gallons a day or less, the schedule's smaller tier.
Johnston County Environmental Health Fee Schedule · checked 2026-09-23
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Bring a document from the planning and zoning office first. Without it, the county will not take a septic permit application.
This is the county's own rule. The state rule, 15A NCAC 18E .0202(h)(8)(C), asks only whether other public offices must approve the lot. Johnston County wants the zoning paper itself before it takes the application.
Johnston County Environmental Health — On-Site Wastewater (Septic Systems) · checked 2026-09-23
Sources
Each figure above has a government source and a checked-on date. USDA's Soil Data Access service supplies the soil records. A script writes them, and nobody types them.
Verify before you act. Septic rules are set locally and they change. Check anything here before you spend money on it. Call the Johnston County Environmental Health Department, on 919-989-5180.