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8 Common Septic Tank Problems & How To Fix Them

Septic tanks are a common way for residential and commercial properties to manage their wastewater in Marin County. However, when they are not maintained properly, septic tanks can suffer from problems that require professional attention. From poor drainage to overflowing sewage, there are numerous issues that can affect your septic tank’s performance.

In this article, we’ll discuss 8 common septic tank problems and how to fix them. We’ll also explain the benefits of regular septic pumping, so you can rest assured that your system is functioning properly. With these tips in mind, you’ll be able to prevent or mitigate the most common septic tank problems.

Let’s dive in.

Solid Buildup

When a septic tank works as it should, all solid materials settle at its base, and the effluent floats to the surface. If you do not have your septic tank pumped regularly, the solids in it will accumulate causing the pipe leading from the house to become blocked. When this happens, your appliances that use water drain at a slow pace or may not drain at all depending on the extent of the blockage. To prevent costly repairs, have a professional pump your septic tank every three to five years.

Septic Tank Overflow

It is not uncommon for septic tanks to overflow after an extreme rain event. Clogged drain lines, solid waste flushed recklessly down the drain, lack of septic tank maintenance, and declining bacterial population in the tank can also cause it to overflow. If your septic tank is overflowing, stop using your plumbing fixtures and contact L.J. Construction immediately.

Strong Odors

When your septic system is functioning properly, it shouldn’t produce any foul smells. A rotten egg odor either inside or outside, indicates potential issues with the septic system. If you smell a rotten egg odor inside your house, sewage may be reversing into a house drain. A strong odor outside (close to the septic tank or drain field) usually occurs when sewage escapes the system before being treated.

A couple of other common problems that can cause septic tank odors include an issue with the soak-away area and solid waste buildup. Harsh chemicals in drain cleaning products can kill the beneficial bacteria in your tank. As the bacteria population in your tank declines, there are not enough bacteria to break down solid waste. Undecomposed solid waste produces strong odors. It is important to not ignore the problem and have a professional inspect your septic tank as soon as possible.

Damage From Tree Roots That Have Infiltrated Your Sewer Lines

Tree roots naturally seek out moisture and nutrients and are often drawn to sources of moisture. If trees are situated close to your septic tank, their roots might penetrate any existing fissures in the tank. Though they might seem innocuous, tree roots can inflict severe, sometimes irreversible damage on septic tanks. Tree roots close to your septic tank can block the inlet pipes and enter the main tank, causing septic tank failure.

Trimming tree roots is not a long-term solution to the problem, as they will regrow over time. To permanently address this issue, septic tank specialists use environmentally friendly chemicals that kill invasive roots without harming the environment.

Instead of waiting for tree roots to enter your septic tank and then address the problem, take a proactive approach. Have your professional perform a comprehensive inspection and check for any infiltrating roots.  If you are looking for a Marin County septic pumping expert, look no further than L.J. Construction.

Collapsed Baffle

The baffles of a septic tank route wastewater through it, while ensuring that solids remain segregated, preventing them from entering the septic tank soak-away system. If a baffle fails, the solids (effluent) might enter the soak-away system, causing blockages. This could result in wastewater reversing into your home. Repairing a baffle (unless it’s a hanging baffle) is almost impossible as it involves digging the septic tank out of the ground and breaking it into two halves. So, if your baffle is damaged, contact a professional immediately.

Broken Drain Lines 

If you park heavy vehicles on your drain field regularly, your drain lines can break. You know your drain lines are damaged if your appliances aren’t draining properly, but the water level in the septic tank remains unchanged. Have a professional address the problem sooner rather than later.

Septic Tank Blockages

Septic tank blockages are arguably the most common septic tank problem. Blockages are caused by solid waste such as vegetable fats, cat litter, and feminine hygiene products flushed down the toilet.

Another common cause of septic tank blockages is infiltrating tree roots. Minor blockages caused by solid waste can usually be fairly easily cleared using plumbing equipment. A major blockage caused by infiltrating tree roots is an emergency that needs attention from an expert.

Soak-away Problems

If the sludge and scum in a septic tank aren’t periodically removed from it– ideally every 3 years – they might build up and flow into the soak-away, clogging the perforated distribution drain pipe or the pores in the earth wall of the soak-away.

Some common signs your soak-away is clogged include wet spots, odors, and unusually lush grass growing near your septic tank. Also over time, your waste plumbing can become less inefficient, and sewage water can back up in your bathtub.

Tips to Prevent Septic Tank Problems

Why wait for septic tank problems to occur and then take remedial action when you can prevent them in the first place? Have a professional inspect and maintain your septic system at regular intervals. Periodic professional septic tank maintenance addresses current problems before they snowball into major issues and prevents potential problems.

Here are some other tips to prevent septic tank problems.

  • Do not drive over the area above your drain field
  • Avoid throwing solid waste down your drain
  • Steer clear of drain cleaning products that contain harsh chemicals


Whether you want to have a new septic system installed or an existing one maintained, L.J. Construction can help. Our septic tank specialists know how different types of septic tanks work. To learn more, call (707) 823-0247