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Septic on Ross Barnett Reservoir Lots

A house near the Ross Barnett Reservoir answers to two sets of rules: the Mississippi State Department of Health, which permits every on-site system, and the Pearl River Valley Water Supply District, which runs the reservoir. Here is where they overlap.

Two regulators on reservoir land

The Pearl River Valley Water Supply District adopts its regulations under Miss. Code Ann. § 51-9-127, and its purpose includes keeping the reservoir water sanitary. The District covers five counties: Hinds, Leake, Madison, Rankin and Scott. Its rules define the Reservoir Project Area as the Ross Barnett Reservoir and any land or easement the District owns, which takes in the Pelahatchie Bay side in Rankin County.

None of that replaces the Mississippi State Department of Health. MSDH still decides what kind of system a lot can have, through the Notice of Intent, the soil and site evaluation and the Permit/Recommendation described on our permit page. What the District adds is a set of steps that depend on MSDH having done its part first.

The floodplain permit needs the MSDH paperwork first

The District's Flood Damage Prevention rules, Part 208, require a development permit from its Floodplain Administrator before development starts. Rule 4.2 is specific: no floodplain development permit can be issued for a mobile, modular or permanently built residence, building or facility unless the owner, lessee or developer has a Notice of Intent from MSDH for a sewage system recommendation, or proof of compliance from the proper sewer and water district.

So on reservoir land the order is fixed. Notice of Intent to MSDH, soil and site evaluation, then the District's floodplain permit, then building. Getting the house plans drawn first and the septic answer second is the expensive way round, especially on Yazoo clay, where the evaluation may rule out a conventional trench.

Subdivision lots need room above the flood line

For platted subdivisions, District Rule 5.5 requires every lot that will be a future building site to have a minimum buildable area outside the natural, unfilled 1 percent annual chance floodplain. That buildable area has to be big enough for the house and its associated structures, and the rule names on-site sewage disposal systems and water wells among them.

MSDH applies a similar test. Its subdivision plans must show frequently flooded areas and the normal and flood elevations of lakes, and where a subdivision includes land in a water storage or flood easement, MSDH wants a letter from the easement holder. Under Rule 3.1.9, a subdivision lying wholly in a wetland or frequently flooded area cannot be approved.

How far the system has to stay from the water

MSDH treats water used for swimming, skiing or fishing as sensitive water, and the reservoir is used for all three. The distances depend on the system:

• Conventional aggregate field: 50 ft from the water's edge, for every soil texture in Table 1.
• Spray irrigation: 50 or 75 ft from the edge of the spray pattern to recreational waters, depending on slope and soil texture.
• Drip irrigation: 100 ft on slopes over 8 percent. On flatter ground, 50 or 100 ft depending on soil texture.
• Elevated sand mound: 100 ft on slopes over 8 percent.

A subsurface field also needs 100 ft from any potable water source, and slopes over 30 percent are not considered for subsurface disposal at all. The full table is on our setbacks page.

District building codes apply too

Part 205 of the District regulations adopts the 2015 International Residential, Building and Plumbing Codes for the Reservoir Project Area, with the District building inspector as the code official. The District adds a requirement that all foundation plans be stamped and signed by a design professional. Building permits and the septic approval are separate tracks, so expect both.

If central sewer is coming to your street, MSDH Rule 1.5.2 allows a temporary system through the Notice of Intent process, but only where the department has written proof from the provider that a connection will be available within 36 months. The temporary system must then be properly abandoned.

Water and sewer service from the District

District Rule 7.1 makes it unlawful to occupy a home or building in the Reservoir Project Area that is served by District water and sewer lines unless it is connected to the District's water system. MSDH Rule 1.2.1 says that where a centralized wastewater treatment system is available, all places must be properly connected to it. Ask the District what serves your lot before you budget for a septic system at all.

If a system is needed, the water meter still follows the MSDH process, which our water meter page explains.

Questions people ask

Does the Reservoir District issue septic permits?

No. MSDH decides the system through its Notice of Intent and Permit/Recommendation. The District requires that MSDH paperwork before it will issue a floodplain development permit for a home.

How close to the reservoir can a drainfield be?

A conventional aggregate field must be at least 50 ft from the water's edge under MSDH Table 1. Spray, drip and mound systems have their own, often larger, distances.

Who do I contact?

MSDH On-Site Wastewater, 1-855-220-0192, for the Notice of Intent. The Pearl River Valley Water Supply District office is at 115 Madison Landing Circle, Ridgeland, for floodplain permits and District service.