How to Winterize Your Septic System in Texas (2026 Guide)

Texas septic tanks rarely freeze underground, but exposed pipes, lids, and aerobic components are vulnerable. Insulate pipes, mulch over the tank, and pump before winter.

Most Texas homeowners don't think about their septic system and cold weather. Then a storm like February 2021 hits, temperatures drop into the single digits for days, and suddenly frozen septic pipes are causing backups into thousands of homes.

You don't need to winterize as aggressively as someone in Minnesota. But a few hours of prep before a freeze warning can save you from expensive emergency repairs. As Nathan Glavy, Extension Program Specialist at Texas A&M's Texas Water Resources Institute, notes in the OSSF education program, the 2021 storm showed that even Texas homeowners need a basic winter prep plan for their septic systems.

Here's what to do.

Do Septic Tanks Actually Freeze in Texas?

The tank itself almost never freezes. It's buried 4-6 feet underground, and the constant flow of warm wastewater keeps the temperature above freezing. But lids, risers, shallow pipes, and drain field lines can freeze solid.

Underground temperatures in Texas stay between 50-65°F year-round at typical septic tank depth. Plus, wastewater enters the tank at near-indoor temperatures (60-80°F), generating enough heat to prevent the tank contents from freezing.

What does freeze:

• Exposed pipe connections where the sewer line exits your house
• Shallow pipes (less than 12 inches deep) between the house and tank
• Plastic riser lids and access covers at ground level
• Aerobic system spray heads and distribution lines
• Pump tank components near the surface

During the 2021 storm, most septic damage in Texas came from frozen pipes between the house and tank, not frozen tanks themselves. Homes with exposed or poorly insulated sewer connections at the foundation wall were hit hardest.

What Should You Do Before the First Hard Freeze?

Complete these steps before the first hard freeze of the season. Most take less than an hour and cost nothing.

Pump if you're due: Schedule pumping before winter if you're within a year of your regular cycle. A tank that's close to full has less room to buffer if a freeze slows drainage. Plus, pumping companies get slammed with emergency calls during storms. Getting ahead saves money and headaches.

Insulate exposed pipes:

• Wrap foam pipe insulation around any exposed sewer pipe where it exits your home. This is the most vulnerable point.
• If you have shallow pipes (common in older Texas installations), add soil or mulch on top to increase ground cover.
• For pipes in crawl spaces, standard pipe insulation sleeves from any hardware store work fine. Heat tape is an option for extreme situations but follow manufacturer instructions to avoid fire risk.

Protect the tank area:

• Pile 8-12 inches of mulch, straw, or leaves over the tank and drain field. This acts as a natural insulation blanket.
• If you have plastic riser lids, insulated riser covers are available for $30-$80. They trap heat from the tank below.
• Don't compact the material. Loose coverage insulates better than packed-down material.

Check your aerobic system:

• Confirm the aerator pump is running. A working aerator generates some heat in the tank.
• Clear any debris from spray heads before freeze season.
• Make sure your alarm panel is functional. You want to know immediately if something stops working during a storm.

Prep your home plumbing:

• Know where your main water shutoff is.
• Keep indoor temperature at 55°F or above, even in unoccupied rooms.
• Open cabinet doors under sinks on exterior walls to let warm air reach pipes.

What Should You Do During a Freeze?

Keep using your system normally. Flowing wastewater generates heat that helps prevent freezing. Don't stop using water entirely unless drains are already frozen.

Counterintuitive advice: moderate water use during a freeze actually protects your septic system. Each flush and drain cycle sends warm water through the pipes, keeping them above freezing. Going to zero water use lets pipes get cold.

Do:

• Continue normal water use (showers, flushing, dishwasher)
• Run a small trickle of water from a faucet if temperatures drop below 20°F for extended periods
• Keep heating on in your home, especially near exterior walls with sewer connections

Don't:

• Pour antifreeze or chemicals into your drains. Antifreeze kills the bacteria that treat wastewater in your tank.
• Pour boiling water down drains to "warm up" the system. Rapid temperature changes can crack cold pipes.
• Drive vehicles over the septic tank or drain field. Frozen, compacted soil offers zero insulation.

What Should You Do If Septic Pipes Freeze?

Stop using water immediately to prevent backup, then call a licensed septic professional. Don't attempt to thaw septic pipes yourself.

Signs of frozen septic pipes:

• Toilets won't flush or flush very slowly
• Drains stop working in multiple fixtures
• Gurgling sounds from drains when no water is running
• Sewage odor from drains

Step-by-step response:

1. Stop water use throughout the house. Every gallon you send down the drain has nowhere to go and will back up.
2. Keep the house heated. Warmth traveling through the foundation can slowly help the pipe where it exits the house.
3. If the frozen section is visible (like an exposed pipe in a crawl space), you can carefully wrap it with warm towels or use a hair dryer on low. Never use an open flame.
4. Call a septic professional. They have pipe-thawing equipment designed for this. Cost for professional thawing: $200-$500 depending on accessibility.
5. After thawing, add insulation to prevent a repeat. Foam sleeves plus heat tape on the trouble section typically cost under $50 in materials.

Don't try to thaw buried pipes yourself. You can't access them safely, and digging in frozen ground near septic components risks damaging the system further.

Why Do Aerobic Systems Need Extra Winter Attention?

Aerobic systems have more freeze-vulnerable components than conventional systems: spray heads, distribution lines, aerator pumps, and control panels can all be affected by hard freezes.

If you have an aerobic system in Texas (TCEQ permit data shows over 500,000 statewide), take these extra steps:

• Spray heads: These sit above ground and freeze first. Some systems have a "recirculate" or "winter mode" setting that keeps effluent in the tank instead of spraying during freezes. Check your owner's manual or ask your maintenance provider.
• Distribution lines: The shallow pipes running to spray heads are vulnerable. Cover the spray field area with mulch before freeze season.
• Aerator pump: If it dies during a freeze and you don't notice, the system loses its oxygen supply. Bacteria start dying within 2 weeks, and treatment quality drops. Make sure your alarm works.
• Power outages: The 2021 storm knocked out power to millions. Without electricity, aerator and effluent pumps stop. If you lose power, minimize water use. The system can handle short outages (24-48 hours) if you conserve water, but extended outages require professional attention.

When Should You Call a Septic Professional?

Call a septic professional if:

• Your drains stop working during or after a freeze
• Your septic alarm goes off during cold weather
• You notice sewage smell or wet areas near the system after a thaw
• Your aerobic spray heads haven't worked since the freeze
• Pipes have been frozen for more than 24 hours

Need winter septic service in Texas? Get free quotes from licensed Texas septic professionals

Frequently Asked Questions

How cold does it have to get to freeze septic pipes in Texas?

Sustained temperatures below 25°F for 12+ hours can freeze shallow or exposed septic pipes. Buried pipes at normal depth (18-36 inches) typically require several days of below-freezing temperatures to freeze. The 2021 storm was so damaging because temperatures stayed below freezing continuously for 4-5 days, long enough to freeze even deeper pipes.

Should I pump my septic tank before winter?

If you're within a year of your regular pumping schedule, yes. A less-full tank gives you a buffer if cold weather slows drainage. It also means one less emergency call during a storm when wait times for septic companies spike to days. If you pumped within the last 2 years, you're probably fine.

Will my septic system work during a power outage?

Conventional gravity-fed systems work fine without power. Aerobic systems and any system with a pump will stop processing once power goes out. You can continue minimal water use for 24-48 hours, but extended outages require drastically reducing water use to avoid overflow. A backup generator for the septic panel ($300-$800 for a portable unit) prevents pump failure during outages.

Can I use salt or de-icer near my septic system?

Avoid it. Salt and chemical de-icers can infiltrate the soil around your tank and drain field, killing the bacteria that treat wastewater. Keep de-icing products away from any area above or near your septic components. Use sand for traction instead.

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Last updated: February 2026 Reviewed by: Texas Septic Guide Editorial Team, TCEQ regulatory research