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The Home Depot

How to Prevent Septic Tank Overflow

Pro Referral > Home Guides > Septic Tank > How to Prevent Septic Tank Overflow
How to Prevent Septic Tank Overflow

As you use water in your home, you will need a system for treating and disposing of wastewater. One method for wastewater management is a septic system. Your septic system is not fail-proof, however, and it requires regular maintenance to work properly.


A possible situation that could occur involves untreated human waste contaminating drinking water, which carries significant threats to both health and the environment. Take steps to prevent septic tank overflow as you maintain your septic system. This will keep your family safe, protect the environment and keep your home in good condition.

  1. You can calculate the septic tank capacity you need by multiplying the number of people living in your home by 150 gallons.

    1.How Septic Systems Work

    A septic system involves a tank buried somewhere in your yard. Rising from the tank, there will be an access pipe that stops at the soil surface. There will also be a drain field buried away from the septic tank.


    When wastewater exits from your home, it travels to the septic tank in the yard. Bacteria that exists in the tank works to break down the waste. Liquids from the tank move through pipes in the drain field, releasing wastewater into the soil under your yard. The soil works to decompose the waste. It’s crucial to keep the septic system maintained properly or raw sewage may rise to the surface of the drain field, which could cause contamination of the drinking water supply and nearby bodies of water.


    The drain field should not be closer than 100 feet to any bodies of water or contamination could occur. In addition, the drain field should not be located downhill from a well.

  2. 2.Septic System Maintenance

    An important consideration is the size of your septic tank to prevent overflows. The amount of water you use will dictate the size tank you need. You can calculate the septic tank capacity you need by multiplying the number of people living in your home by 150 gallons. The answer should equal the capacity of your septic tank. If your septic tank is not this large, you run the risk of overflow.


    A septic tank should be big enough to hold an accumulation of two days of wastewater from heavy-use days. If your tank is too small, it may overflow on days that you use more water.


    With proper pumping, a septic system should last between 20 and 30 years. Hire a professional to pump your septic system every three to five years.

  4. 3.Drain Field Maintenance

    Do not allow vehicles or equipment to drive or sit on your drain field, because this could compact the soil. Compacted soil could diminish the soil’s ability to decompose waste. Do not allow trees and shrubs to grow closer than 50 feet to the drain field or roots may interfere with waste decomposition. Grass growing above the drain field will not interfere with decomposition.


    Direct gutters away from the drain field and do not allow rainwater to form puddles near the drain field.


    As long as your septic tank is the correct size for your family size and as long as you maintain a regular schedule of maintenance, you should be able to prevent septic tank overflow. If unfortunately you have already experienced an overflow problem, please consult: How to Treat Septic Tank Overflow

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