Building permits, zoning and septic rules in Forrest County, Mississippi

Forrest County does not administer building codes or issue county certificates of occupancy in unincorporated areas¹. We could not confirm whether another authority requires residential building permits or inspections, so ask County Planning before treating a parcel as permit-free¹. Inside Hattiesburg, the city generally requires building permits for new residences and residential repairs or alterations; Petal requires its building permit to be issued and displayed before work begins^10,11. MSDH still administers onsite wastewater approval in both cities, with additional city private-sewage requirements in Hattiesburg^4,12. Mississippi's owner-builder exemption concerns residential-builder licensing for work on the owner's own residence; it does not waive a required building permit or inspection⁷.

Forrest County Planning is the first stop before any development on unincorporated land for stormwater, floodplain and subdivision compliance¹. The Planning Department is at 641 N Main Street in Hattiesburg and can be reached at (601) 545-6000¹. For land disturbance up to 0.9 acre, the published stormwater rules require notification to Planning but no stormwater permit or stormwater pollution-prevention plan¹³. Disturbing 1 to 5 acres requires a county stormwater permit, Notice of Intent and pollution-prevention plan; more than 5 acres requires filings with the Mississippi Department of Environmental Quality and a copy to County Planning¹³. Forrest County also has a floodplain development ordinance, but its permit procedure, numeric standards and exceptions remain unconfirmed; ask Planning how the ordinance affects the site¹.

The Mississippi State Department of Health Division of On-Site Wastewater handles septic regulation and approval in Forrest County³. Installing an onsite system requires a septic permit, and a permanent water meter requires an approved permanent sewage-disposal solution⁵. Public sewer has first right to serve; MSDH refers applications within 1 mile of a sewer line for connection and requires a sewer-provider rejection letter before proceeding with septic approval⁵. Household wastewater, including gray water, must go to sewer or septic rather than the ground, ditches or bodies of water⁵. Listed residential fees are $197.50 for Notice of Intent plus final approval and $100 for Notice of Intent plus exemption; fees can change, and processing or other costs may apply⁵. About 34% of Forrest County soils are rated not limited for conventional drain fields; that countywide rating does not establish suitability of a particular lot, so arrange a site evaluation early¹⁴.

1. Establish whether the address is unincorporated or inside Hattiesburg or Petal: the cities handle their own building permits, while County Planning directs applicants to contact it before unincorporated development^1,10,11.
2. Tell County Planning the disturbed acreage and ask how stormwater and floodplain requirements apply^1,13.
3. Resolve sewer availability with the provider and MSDH before applying for septic approval or arranging a permanent water meter⁵.
4. For a division into 4 or more lots outside city limits, submit the surveyed plat and improvement plans to the Board of Supervisors; agricultural divisions without new roads or streets are exempt from the subdivision ordinance only⁸.
5. Obtain an MDOT driveway permit for a new or altered connection to a state highway¹⁵.

Mississippi does not require a septic inspection solely because a home is being sold, but MSDH recommends one; lenders, utilities, local authorities or parties to the sale may request it, and separate installation or advanced-treatment requirements still apply¹⁶. MSDH lists an existing-residential inspection at $100, subject to change¹⁶. For a covered unincorporated subdivision, an existing sewer main within 500 feet requires sewer construction if acceptable to the municipality; an available water utility within 500 feet triggers certificate and contract documentation⁸. Developers also bear subdivision road-inspection costs determined by the County Engineer and approved by the Board of Supervisors⁸. A subdivision driveway crossing a drainage ditch must be at least 20 feet wide with a culvert laid to the ditch profile; this does not establish a general single-parcel driveway permit⁸. A state groundwater withdrawal permit generally applies to wells with surface casing at least 6 inches in diameter, subject to exclusions⁹.