Septic and Well Checks Before You Buy Outside City Limits

If a home outside city limits runs on an on-site sewage facility (OSSF, usually called a septic system) and a private well, checking both is mostly up to you as the buyer. Before your option period ends, pull the septic permit, learn what kind of system it is and who maintains it, have both systems inspected, and get the water tested.

Nobody does this for you automatically. TCEQ says a septic evaluation a lender may require is not required or regulated by TCEQ.

The Texas Water Development Board notes that the state does not regulate water quality in private wells. And a TREC-licensed inspector is not required to inspect either system unless they agree to.

Who permits septic systems here

TCEQ regulates septic systems statewide, and many local governments act as its authorized agents. In Comal County, that’s the County Engineer’s Office Environmental Health Department, which reviews designs, issues permits and responds to complaints.

A permit and approved plans are required before building, altering, extending or operating a system, and Comal County requires a permit for every system regardless of acreage. After the installation inspections, the county issues a license to operate.

Start with that record. Comal County’s permit search lets you look up permits by address or subdivision. I’d compare the permitted system type and layout with what’s actually in the yard.

Buying in another county? TCEQ’s site has a search for your local permitting authority. TCEQ also has a rule revision project that includes maintenance contract requirements, so confirm the current rules with the county.

Conventional or aerobic, and the maintenance rules

A conventional system is a septic tank with a drainfield. TCEQ recommends pumping the tank every three to five years.

An aerobic treatment unit is one way to get secondary treatment, which can feed spray heads (surface application) or other disposal methods. TCEQ’s suitability table marks a septic tank with an absorptive drainfield as unsuitable in fractured rock, while surface application with secondary treatment is suitable across soil classes, with vegetation cover and disinfection. Secondary treatment must be designed by a professional engineer or sanitarian.

Aerobic maintenance follows the state rule at 30 TAC 285.7:

• A new system comes with a two-year service policy from first use. If the home sells during that period, the policy’s terms carry over to the new owner.
• After that, the owner of a single-family home can maintain the system personally or sign a contract with a licensed maintenance provider. Owner maintenance isn’t allowed for commercial, speculative residential or multifamily property.
• Under a contract, the provider reports test results to the county and to you within 14 days, and marks a weather-resistant tag on the unit at each visit. TCEQ sets reporting at least every four months, or every six months with electronic monitoring.

In Comal County, a homeowner who maintains a single-family aerobic system doesn’t need training, doesn’t file reports and doesn’t have to notify the county. If the county finds a violation that isn’t corrected within 10 days, the owner must sign a maintenance contract, and two violations within three years also require one.

For chlorine disinfection, TCEQ says to use calcium hypochlorite tablets certified for wastewater, and never swimming pool tablets. Comal County’s rules also keep the spray area at least 20 feet from the property line and keep items like picnic tables and BBQ pits out of it.

How to inspect the septic system

If your TREC inspector agrees to inspect the system, the standards of practice call for reporting its type, where the drain or distribution field is, and how close it sits to wells and property lines. The inspector flags effluent at the surface and inoperative aerators or dosing pumps, but isn’t required to dig the system up or judge whether it’s adequately sized.

For more depth, consider an evaluation by a TCEQ-licensed professional, such as an installer or maintenance provider, and a pump-out by a TCEQ-registered sludge transporter. Ask the seller:

• When the tank was last pumped, and for recent maintenance reports.
• How old the system is. TCEQ lists age as a cause of failure and says a system more than 15 years old may need to be replaced.
• Whether anything sits on top of it. TCEQ says not to build driveways, barns, storage buildings, sidewalks or patios over any part of a system.

Near Canyon Lake, the Corps of Engineers won’t allow septic tanks below the 948-foot elevation in flowage easements and requires spray zones to stay at least 75 feet from the 940-foot contour.

After closing, TCEQ advises notifying the local permitting authority that you’re the new owner of the system.

Well water: records, testing and the well itself

Start with the well’s paperwork. The Texas Water Development Board’s driller report database can be searched by map or tracking number, and reports mailed in before the database existed are on TCEQ’s Water Well Report Viewer.

Ask the seller for TREC’s Seller’s Disclosure about Groundwater and Surface Water Rights. It covers district registrations, wells shared with neighbors and any severed groundwater rights.

Know which district applies. Trinity Aquifer wells in Comal County fall under the Comal Trinity Groundwater Conservation District, and the Edwards Aquifer Authority requires every well that draws from the Edwards to be registered.

Then test the water. Texas A&M AgriLife’s Water Well Basics recommends testing at least once a year for nitrate, total dissolved solids, and E. coli or fecal coliform, through a certified drinking water laboratory.

The same guide lists minimum distances Texas law sets for a wellhead, including 50 feet from a septic tank and 100 feet from a drainfield. Compare those with the septic permit drawing.

If the inspection covers the well, TREC standards require running at least two fixtures at once, recommending or arranging a coliform test, and reporting the pump, storage equipment and any known septic system nearby. The inspector doesn’t judge whether the supply is reliable, so for the pump and well, call a driller or pump installer licensed by TDLR.

Your checklist

1. Pull the septic permit and compare it with the site.
2. Identify the system type and who maintains it.
3. Get maintenance reports and the last pump-out date.
4. Add septic and well to your inspection, or hire specialists.
5. Find the well report and the groundwater district.
6. Get the Seller’s Water Disclosure.
7. Test the water through a certified lab.
8. Check the distances between the well and the septic system.
9. After closing, notify the county and set up maintenance.

If you’re weighing a rural home

Most of these checks can start on the first day of your option period, which leaves time to act on what you find. My Hill Country Buyer’s Guide covers the rest of the rural-property list in one place.