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Why Is My Septic System Overflowing? Treating Your Overflowing Septic Tank

In areas without municipal sewer systems, septic systems are how households process waste. Wastewater exits the home through a series of pipes until it reaches the septic tank, where solid waste settles to the bottom and the remaining water passes into the drain field. The process keeps your home free of wastewater and any issues it may bring, but an overflowing tank causes big problems. There are many factors that cause a septic tank to overflow and figuring out what is causing yours to overflow helps you determine the best possible solution.

What Causes Septic Overflow?

Septic overflow can be caused by multiple things. Some of the most common causes include:

  • Bacterial deficiency: The waste in a septic tank is broken down by bacteria, allowing water and other liquid waste to pass through to the drain field. But if your bacteria levels are low, the solids won't break down and your system fills up quickly, causing overflow. Try to avoid putting bleach, chemical cleaners, and other disinfectants down your waste piping to keep from killing the bacteria.
  • Clogs and design flaws: Wastewater passes through a series of pipes before entering the tank and then another series of pipes into the drain field. If these pipes become clogged, nothing can pass through properly, leading to overflow. Plants near the drain field can also cause issues, as the roots may disrupt the piping. Improper design is also a major cause of overflow, because if the drainage pipes do not have the proper slope, nothing moves through properly. In this case, the pipes need to be replaced.
  • Heavy rains: It is not uncommon to experience septic issues after heavy rain or major storms. This excess water often floods the ground around the drain field, making it impossible for wastewater to exit your septic system. A flooded drain field causes the water to travel backward through your system, into the drains of your home.
  • Inadequate maintenance: It is incredibly important that your septic system receives adequate and proper maintenance, a big part of which is pumping the septic tank. If the tank is not pumped when it should be (two to four years is the average), overflow is bound to happen.

Fixing Overflow

Septic overflow is something you want to avoid entirely. Beyond bringing intense odors, it often causes major damage to the septic system as a whole and leads to costly repairs. But when overflow does occur, there are things you can do to fix it.

  • Avoid pumping the tank: Pumping your septic tank is definitely a way to fix overflow if the problem is in the tank. However, it should never be your go-to solution. If the drain field is flooded, the weight of the solid waste in the tank is what keeps it in place. Emptying the tank may cause it to move toward the surface, which leads to damaged or dislodged pipes. If that happens, now you have a whole new problem to worry about.
  • Inspect the tank: When flooding or overflow occurs, tank inspection is important. This does not necessarily mean that it needs to be pumped, but any time septic overflow happens it's a good idea to check the tank. This should be done by a professional after the ground dries. If there is any damage to the tank, you can handle the problem faster.
  • Watch your water use: If the drain field is flooded, there is a high possibility that the water is going to flow back into the septic tank and cause overflow. Because of this, it is recommended that you limit your water use. Keep time spent in the shower down and avoid running your dishwasher or washing machine until the flooding has been resolved.

How Much Does Septic System Maintenance Cost?

Preventive maintenance costs center around pumping the septic tank and replacing parts as required.

  • It costs between $75 and $150 on average to pump a small septic tank
  • It costs around $200 to $400 to pump a mid-sized septic tank
  • Pumping a large septic tank costs between $500 and $750
  • A new, high-quality filter averages around $200 to $300
  • New PVC pipes and fittings range from $50 to $200
  • If you need a new pump, expect it to cost between $300 and $4500
  • An entirely new septic system starts at around $3,000 for smaller properties but upwards of $20,000 for larger properties and tanks

Failure to properly maintain your septic tank has enormous costs beyond replacing your system. If it backs up, you likely face repairs to your landscaping and may have plumbing costs and even household repairs if the backup was severe enough.

Be Proactive with Your Septic System

Nobody wants to experience septic overflow; the issues it brings are often costly and almost always odorous. Your septic tank has a limited capacity and is only able to hold so much. Have your system regularly serviced and pump the tank whenever necessary. Conserving water is also a great way to prevent overflow, since you limit the amount of water pushing through the system. And remember that you should not flush anything down the toilet or wash anything down the drain that isn't meant to be there.

Septic overflow is always preventable. You just have to consider what must be done to keep your septic system healthy. Talk to a professional with experience in working with septic systems, not just to service your system, but to see what you can do to keep it running well.