Official sources checked August 31, 2026

Johnston County, North Carolina septic permits and requirements

Johnston County Environmental Health is the local permitting office

Johnston County Public Health’s Environmental Health Department administers well and septic permits. The county’s current staff directory identifies an On-Site Wastewater supervisor, soil specialists, and On-Site Wastewater program specialists at the Smithfield Environmental Health office.

New systems require an application, site plan, zoning document, and fee

Johnston County’s septic application instructs applicants to submit a completed application, site plan, zoning document from the appropriate zoning district, and the required fee for each lot. The form provides separate application paths for a new system, repair, replacement, and an open-permit revision requiring a site visit.

Prepare the property for the site and soil evaluation

The county’s septic-application instructions require a completed site plan and, for new-system evaluations, accessible site conditions and flagged property corners. The guidance warns against disturbing or reshaping the soil in the proposed septic or repair area because site disturbance can affect suitability or an existing permit.

Current county septic fees are published

Johnston County’s Environmental Health fee schedule is effective July 1, 2025. It lists $500 for a septic-system permit at 480 gallons or less, $575 for large-system design above 480 gallons, $250 for an existing-system upgrade or replacement, $175 for an open-permit revision requiring a site visit, $50 for a revision not requiring a site visit, $150 for Existing System Approval, and $100 for installation or reinspection. The schedule lists septic repair as no charge. Applicants should still confirm the current category before filing.

Existing systems have a separate approval path

Johnston County publishes a separate Application for the Approval to Use an Existing Wastewater System. That application requires a site plan and fee and identifies Local Health Department, AOWE, and Certified Inspector pathways, so reuse of an existing system for a new project should not be assumed without the applicable approval.

Inspection and permit status can be checked online

Johnston County provides a public Environmental Health search for septic and well inspection status by address or permit number. The county directs owners who cannot locate a septic permit through the search to contact Environmental Health for a copy.

Official sources

• Johnston County Environmental Health
• Johnston County — septic system and well application
• Johnston County — approval to use an existing wastewater system
• Johnston County Environmental Health — current fee schedule
• Johnston County — septic and well permit / inspection status search
• Johnston County Environmental Health — staff directory
• NCDHHS — On-Site Wastewater Program

SepticScope summarizes public-agency information for planning purposes. The permitting agency's current instructions control if they differ from this guide.