You already know that winter temperatures can freeze plumbing pipes. But did you know that frost can freeze your septic system, too? Yikes!

Depending on the depth of septic pipes and depth of frost, your septic pipes, tank, or soil treatment system can freeze. Dirty water and sludge can backflow in your home’s plumbing, filling your tub, toilet, and faucets. Talk about a mess!

Septic outside

How Does It Happen?

Generally, a septic system has four main components where freezing can occur:

  • The pipe running from the house to the septic tank
  • The septic tank
  • The pipe from the septic tank to the soil treatment system (the drain field)
  • The soil treatment system

Snow acts as an insulator for soil, but driving vehicles or equipment over your septic system location can compact snow and send frost deeper into the soil.

If your septic tank is filled to capacity, its frozen liquid contents can freeze and push back up into your pipes -- yuck! It’s important to have a professional check the tank before winter to ensure it has enough space to handle the amount of water flushed during freezing months.

When a home is left unoccupied for long weekends, a septic system struggles to maintain high enough temperatures to avoid freezing. During extreme cold, it’s important that your septic system gets frequent use, warmer water temperatures, and greater water use overall.

My Septic System Froze -- What Should I Do?

A frozen septic system is NOT something you can fix with a simple Google search! If your septic system freezes, your first step should be to call a professional. If you have a pump and hear water running, shut off your pump to prevent costly water leaks.

Avoid these common homeowner mistakes:

  • Do not add antifreeze, salt, or a septic system additive into the system
  • Do not pump sewage onto the ground surface
  • Do not start a fire over the system to attempt to thaw it out
  • Do not run water continually to try to unfreeze system
     

How Professional Plumbers Handle Frozen Septic Systems

Septic systems have many factors that can lead to ice formation. Before a plumber can address the specific problem, they will need to de-ice your frozen septic line and re-open the system.

A professional plumber will conduct an on-site evaluation of your septic tank symptoms. A plumber may use heat tape and tank heaters to keep your system at a regulated temperature if it has not frozen yet. If it has frozen, professionals have access to steamers and high-pressure jetters to try to unfreeze system piping. However, the cause of freezing must still be corrected to prevent piping from refreezing. Cameras can be sent down pipes to determine where freezing is occurring and if repairs are needed.

In some cases, the system cannot accept liquid until the area is thawed in spring. If it is simply too cold, options are limited and you may have to use the tank in the system as a holding tank until the system thaws naturally. A septic pumper will have to empty out the tanks when they are full. This is a costly option, so it’s essential to prevent your septic system from freezing in the first place!

Prevent a Frozen Septic System

There are several steps you can take to prevent a frozen septic system. Talk to your Benjamin Franklin plumber to determine the most effective steps. Some steps, such as insulating your system, will require a professional.

  • 1. Place a 12 inch layer of mulch, straw, leaves, hay or other loose material over pipes, tank and soil treatment system to provide extra insulation (if your system is currently frozen, ignore this step so it does not interfere with thawing in warmer temperatures).
  • 2. Let lawn grass grow longer in late summer/fall over the tank and soil treatment area to help provide extra insulation.
  • 3. Use warm water more frequently during extreme cold spells. Spread out your laundry schedule throughout the week, use your dishwasher, and take hot showers.
  • 4. If you know you are going to be gone for an extended period, plan ahead. This could include asking someone to use quantities of water in the home regularly or emptying your tank before leaving.
  • 5. Fix leaky plumbing fixtures and appliances in your home before winter hits. This helps prevent freezing problems and helps your system work better year round.
  • 6. Keep vehicles off of the ground above the system to avoid compacting snow and frost.
  • 7. Ask your plumber to add covers and insulation to all risers, inspections pipes, and manholes.
  • 8. Add more insulation to your system: ask a plumber to replace regular pipe with insulated pipe, add styrofoam over septic tanks, and add more soil cover.