Why does my septic backup when it rains?

Asked By: Sergio Abramenkoff | Last Updated: 14th February, 2020
Category: business and finance green solutions
4.7/5 (413 Views . 23 Votes)
It is common to have a septic back up after or even during a heavy rain. Significant rainfall can quickly flood the ground around the soil absorption area (drainfield) leaving it saturated, making it impossible for water to flow out of your septic system.

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Correspondingly, can too much rain affect my septic tank?

Yes! Heavy rain and other water sources that oversaturate the soil around your septic tank can cause your tank to flood. This can be a serious and delicate issue, so be sure to contact a septic tank professional when your system is flooded. In simple terms, septic tanks have three primary units.

One may also ask, will a flooded septic tank fix itself? Most septic tanks are not damaged by flooding since they are below ground and completely covered. However, septic tanks and pump chambers can fill with silt and debris, and must be professionally cleaned. If the soil absorption field is clogged with silt, a new system may have to be installed.

Moreover, can heavy rain cause sewer backup?

During heavy rains, combined sewer systems can become overwhelmed with water. This can cause sewer water to back up in the system and sometimes into homes. Sewer backups can be caused by individual service lines being plugged by grease, waste, tree roots, breaks in pipes or saturated ground.

How do I stop my septic tank from backing up?

Septic Tank Backup Prevention

  1. Make sure your septic tank is always biologically active. Don't use antibacterial soaps and cleaners that drain to the tank.
  2. Never put garbage or any foreign objects into the system.
  3. Avoid planting trees anywhere near your septic lines.
  4. Do not run heavy machinery over sewer lines.

35 Related Question Answers Found

Is Dawn dishwashing liquid safe for septic systems?

Re: Dawn difference to others dish soap
All surfactants are readily biodegradable. These products are safe for septic tanks. There is a reason it's used during ecological disasters like the accident with the Exxon Valdez.

Why is my septic tank filling up so fast?

A stubborn tank that keeps filling up may signal a problem with your drainfield. But if your drainfield is clogged or failing, it won't be able to properly drain wastewater. The liquid waste will have nowhere to go! In turn, the water will back up into the tank, causing it to quickly fill up.

How many loads of laundry can I do with a septic tank?

Spread it out and do one load a day for several days. A typical washing machine uses 30 to 40 gallons of water per load. If you do 5 loads of laundry in one day, that pumps at least 150-200 gallons of water into your lateral lines. Most septic systems 10 years old or older have a 600-900 square-foot absorption area.

How long does it take for a flooded septic tank to drain?

Except for mound systems, most drainfields are 2 to 4 feet below ground surface. It will take time for the groundwater to recede to the level of the bottom of the drainfield. This could happen within a week or two, or require a couple months.

Why do I smell my septic tank when it rains?


Why It Smells
Inside your septic tank is methane gas, which produces an extremely strong odor. When it rains, the air becomes heavier and prevents the methane gas from rising up and through the septic tank's vent. As a result, the methane remains low to the ground, resulting in that all too familiar rotten egg smell.

How do you fix a flooded septic tank?

If you suspect flooding of your septic system, here are four things you should do.
  1. Check the Groundwater Level. Drainfields for septic tanks are normally between 2 to 4 feet from the top of the soil.
  2. Wait to Pump Until the Ground Dries.
  3. Reduce Water Sent Down the Drain.
  4. Make Changes to Help Your Newly Pumped Septic System.

What to put in septic tank to break down solids?

Yeast helps keep bacteria alive and actively breaks down waste solids when added to your septic system. Flush ½ cup of instant dry baking yeast down the toilet, the first time. Add ¼ cup of instant yeast every 4 months, after the initial addition.

How long will a septic system last?

Typically, a steel septic tank will last between 15 and 20 years. Tanks made of concrete or plastic are usually preferable in terms of longevity. A properly maintained septic system with a concrete tank can last well over 40 years.

Is city responsible for sewer backup?

When the subject of sewer backups comes up, City representatives have consistently stated that the law holds a municipality responsible for sewer backups only if the problem is caused by a defect, and not if “the sewage backup was caused by a rain event greater than what the sewage system was designed to carry.”

How do I fix water seeping through my basement floor?


Here are eight strategies to keep water out of your basement.
  1. Add Gutter Extensions.
  2. Plug Gaps.
  3. Restore the Crown.
  4. Reshape the Landscape.
  5. Repair Footing Drains.
  6. Install a Curtain Drain.
  7. Pump the Water.
  8. Waterproof the Walls.

Why is water coming up through the floor?

Common causes are leaks in the ceiling or a crack in the exterior of the home which both permit water to enter. If the water is seeping up through the floor, it could be a result of insufficiently-sealed foundations or there could be cracks in the foundation floor.

Can water come up through concrete basement floor?

Ground Water
The most probable explanation for why water is coming up from your basement floor is groundwater. This can include cracks in your floor, cracks in the wall, and yes even through the floor. Your basement floor is made of concrete, and concrete is porous allowing water to soak through it.

What causes sewer line to back up?

Sewer Backup Caused by Clogs
The most common type of sewer backup is from clogged pipes. The combination of toilet paper, hair, soap scum and grease (as well as a two-year-old's fascination with what will and will not flush) are common causes of sewer backups.

How do you reduce hydrostatic pressure?

The only way to relieve hydrostatic pressure around your foundation is to divert water away. You will need to restructure your drainage system or add supplemental drains to direct water in a way that it does not seep into the ground surrounding your basement walls, regardless of their concrete strength.

Does rainwater go into the sewer?


Most rainwater falling on properties drains into public sewers owned by the ten water and sewerage companies in England and Wales. If rainwater does not drain from your property into a public sewer, because you have a soakaway or similar, you may be entitled to a surface water drainage rebate.

Can Rain Cause toilet problems?

If you are tied into the city sewer system, a backed-up toilet, during heavy rain, can be due to a cracked sewer pipe somewhere outside of your home.

How do you know if your main drain is clogged?

Warning Signs of a Main Sewer Line Clog
  1. Clogged drain or toilet. The most common red flags, sewer main cleaners say, are water backing up out of a drain or the toilet plumbing, or a gurgling sound coming from the drains.
  2. Tree roots.
  3. Release the pressure.
  4. Request a camera inspection.