How to Clean Up After a Septic Tank Overflow

A septic tank overflow can create a hazardous and unpleasant mess, both inside your home and in your yard. Cleaning up after an overflow requires proper handling to ensure the safety of your family, prevent contamination, and protect your property.

Here’s a step-by-step guide on how to safely clean up after a septic tank overflow, whether the issue occurred indoors or outdoors.

Safety First: What to Do Immediately After an Overflow

Before beginning any cleanup, prioritize safety:

Avoid direct contact with sewage: Septic waste contains harmful bacteria, viruses, and pathogens. Wear protective gear such as gloves, rubber boots, and a face mask to prevent exposure.
Keep children and pets away: Limit access to the affected area to prevent illness or contamination.
Stop using water: If the septic tank is overflowing, stop using water in your home to avoid adding more wastewater to the system.

Step-by-Step Cleanup for Indoor Overflows

1. Block Off the Affected Area

Seal off rooms or areas where the overflow occurred to prevent the spread of contamination. Avoid using the plumbing system until the septic tank is serviced by a professional.

Tip: Use towels, plastic sheeting, or barriers to block doorways and limit the spread of sewage to other areas.

2. Remove Standing Water

Use a wet/dry vacuum or a pump to remove any standing water or sewage. Dispose of the water in a safe and sanitary manner by following local regulations, as this water is considered hazardous.

Tip: If the overflow is significant, call a professional restoration company with equipment designed to handle biohazard cleanup.

3. Dispose of Contaminated Items

Items that have been soaked in sewage, such as carpets, rugs, furniture, and mattresses, may need to be thrown away. Fabrics and porous materials can harbor harmful bacteria even after cleaning.

Tip: Bag contaminated items in heavy-duty trash bags and follow local disposal regulations.

4. Clean and Disinfect Hard Surfaces

Hard surfaces like tile, concrete, and hardwood floors can be cleaned and disinfected thoroughly:

Use a non-ammonia soap or detergent to wash the surfaces.
Disinfect with a solution of 1 cup of bleach to 1 gallon of water. Apply to all hard surfaces and let it sit for at least 15 minutes before rinsing.
Tip: Ensure proper ventilation when using bleach or disinfectants.

5. Dry and Dehumidify the Area

After cleaning, dry the area completely to prevent mold and mildew growth. Use fans, dehumidifiers, and open windows to increase air circulation.

Tip: If moisture is trapped, it can lead to mold growth, which can cause long-term damage and health problems.

6. Clean and Disinfect Plumbing Fixtures

Flush and clean toilets, sinks, and other affected plumbing fixtures. Make sure the septic system is functioning correctly before using them again.

Tip: Use a plumbing-safe disinfectant to thoroughly clean the fixtures.

Step-by-Step Cleanup for Outdoor Overflows

If your septic tank overflowed into your yard, it’s important to clean up the area carefully to avoid contaminating the soil, water, and nearby areas.

1. Contain the Spill

If sewage is pooling on your lawn, use barriers like sandbags or soil to prevent the waste from spreading further. This is particularly important if the overflow is near gardens, wells, or water bodies.

Tip: Make sure rainwater or irrigation water is diverted away from the contaminated area.

2. Remove Solids

Using a shovel, carefully scoop and bag any visible solid waste. Double-bag the waste in heavy-duty trash bags to prevent leakage, and follow your local hazardous waste disposal guidelines for proper disposal.

Tip: Wear protective gloves and boots to avoid direct contact with sewage.

3. Disinfect the Area

After removing solids, use garden lime to neutralize and disinfect the affected soil. Sprinkle a generous amount of garden lime over the contaminated area and let it sit for 24 hours. The lime helps to kill bacteria and neutralize odors.

Tip: Once the lime has been applied, restrict access to the area for pets and children.

4. Rake and Aerate the Soil

After the lime has sat for 24 hours, rake the treated soil to help it absorb the disinfectant. Water the area lightly to help the lime penetrate deeper into the soil.

Tip: If the contaminated area is large, you may need to aerate the soil to restore proper drainage.

5. Monitor for Plant and Grass Health

Contaminated soil can lead to dead grass and plants in the affected area. Monitor the area to see if plants need to be replaced or the soil needs additional treatment. In some cases, you may need to remove and replace the top layer of soil.

Tip: If the area shows signs of lasting contamination or plant death, consult a landscaping professional.

Disposing of Contaminated Waste

All waste collected during the cleanup (e.g., contaminated clothing, carpets, soil, and sewage) should be treated as hazardous waste. Check with your local health department or waste management facility for guidelines on how to safely dispose of these materials.

Tip: Do not throw contaminated items in the regular trash, as this can spread harmful bacteria.

Professional Cleanup Services

If the septic tank overflow is severe, or if you’re unable to handle the cleanup yourself, it’s best to call a professional cleanup and restoration company. These companies specialize in biohazard cleanup and can handle large-scale cleanups safely and efficiently.

Tip: Look for a company certified by the Institute of Inspection Cleaning and Restoration Certification (IICRC) for biohazard and sewage cleanup.

Preventing Future Overflows

Once the immediate cleanup is completed, take steps to prevent future overflows:

Schedule regular septic tank pump-outs (every 3-5 years).
Conserve water usage to avoid overloading the system.
Avoid flushing non-septic-safe items, such as wipes, diapers, or feminine products.
Inspect your system regularly to catch early signs of failure.
Divert rainwater and runoff away from the septic system.

Table: Septic Overflow Cleanup Steps

Cleanup Step	Action
Stop water usage	Minimize water usage to prevent further overflow or backups.
Remove standing water	Use a wet/dry vacuum or pump to remove sewage and standing water.
Dispose of contaminated items	Safely bag and dispose of sewage-soaked items according to local regulations.
Disinfect hard surfaces	Use bleach or disinfectant on affected floors, walls, and fixtures.
Apply garden lime outdoors	Neutralize bacteria in the soil by applying garden lime to the contaminated area.
Dry and dehumidify	Use fans and dehumidifiers to dry indoor spaces to prevent mold growth.
Call a professional if necessary	Hire certified biohazard cleanup services if the damage is extensive.

Conclusion

Cleaning up after a septic tank overflow requires thorough attention to safety and sanitation. Whether the overflow happens inside your home or in your yard, it’s crucial to remove contaminated water and waste, disinfect affected areas, and dispose of hazardous materials correctly. If the cleanup seems too extensive or hazardous, professional biohazard cleanup services are a safe and effective option. To prevent future overflows, maintain your septic system regularly and be mindful of water usage and proper disposal habits.