Do I need a permit for well or septic work in Mississippi?

Short answer: for anything beyond routine service, yes. In Mississippi, as in every state, this work is regulated because it touches the groundwater your neighbors drink.

Work that needs a permit or approval

• Installing or replacing a septic system: always permitted, and the design must match a soil evaluation of your site.
• Septic repairs that alter the system: replacing a tank or drainfield needs approval; fixing a broken lid or baffle usually doesn't.
• Drilling a new well: permitted and logged, so the state knows what is going into the aquifer.
• Deepening or hydrofracturing an existing well: typically treated like new construction.
• Decommissioning: sealing an abandoned well or septic tank is regulated too; an open one is a direct contamination path.

Work that usually doesn't

• Routine septic tank pumping and cleaning
• Like-for-like well pump or pressure tank replacement (some jurisdictions still want a notice; ask)
• Water testing and inspections

Mississippi agency resources

• Mississippi MSDH - Private Water Wells

Who pulls the permit?

Usually your contractor. Licensed installers and drillers handle permitting as part of the job, and in many jurisdictions only a licensed contractor can pull the permit at all. Confirm the quote includes permits and the final inspection. 539 licensed pros are listed for Mississippi; browse by county or request free quotes and ask each one how they handle permitting.