Septic System Safe Laundry Detergents

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Nearly 25 percent of United States households use a septic system as the means of water and sewage disposal. The key to maintaining a healthy septic system is to understand how the system works and then follow practices to keep it healthy.

Doing laundry and home septic tanks can work well together. Septic tank systems are something we don't like to think about and, usually, don't until there is a problem.

A septic tank handles all of the waste water from homes that are not connected to a public sewer system.

Laundry Tips for Healthy Septic Systems

Laundry contributes a great deal of water to the system. Here are a few tips you should follow to prevent problems:

  • Try to do no more than one or two loads of laundry each day. It is better to spread out a week's worth of washing rather than run multiple loads on a single day especially if you have a standard washer that uses a large amount of water for each load.
  • If possible, purchase a new top loading or front loading high efficiency washer to replace your old standard top loading washer. High efficiency washers use around 15 gallons of water for each load verses 30 to 40 gallons of a standard machine.
  • To keep the system healthy, do not run laundry wastewater directly into the septic system drain field; it should be run into the septic tank. Soap or detergent scum can plug the soil pores in the drain field and cause the system to fail.
  • Normal amounts of detergents and bleaches can be used and won't stop or harm the bacterial action in the septic tank. However, using excessive amounts of soap or detergent can cause problems with the septic system. Many laundry detergents contain nonylphenol ethoxylate surfactants. Surfactants are the ingredients that make detergents effective in lifting soil particles off the surface of a fabric. These chemicals can be serious contaminants of ground water and surface water in the environment if not handled properly in a septic system.
  • It is possible for powdered detergent to form clogs in a septic system reducing septic tank processing speed and in severe cases even blocking a drain. Inexpensive powdered detergents may contain excessive amounts of filler or carrier. Some of the fillers can be montmorillonite clay that is used to actually seal soils. The best solution is to use a liquid laundry detergent or a single dose detergent pod without fillers that may harm a septic system.

  • Homemade laundry products are safe to use with septic systems because they do not contain soil-clogging fillers.
  • If you experience regular problems with blockages in your septic system's drainage lines to the drainage field, install a lint filter in the washer's drainage line. This should be cleaned regularly and will prevent problems with the septic system.
  • Consider installing a dry well to capture laundry greywater. If you use plant-based environmentally friendly laundry products, laundry greywater can be used for irrigation of lawns and landscape plantings. Many municipal systems in drought prone areas offer classes and discounts on hardware to install greywater irrigation systems.

Selecting a Laundry Detergent for a Healthy Septic System

The type of septic system will determine which type of laundry detergent is the safest to use.

For a conventional, gravity-powered system, use a liquid form of laundry detergents. However, for an aerated septic system, the better choice is a powdered septic tank safe laundry detergent to avoid excessive foam in the aeration chamber.

Septic tank safe detergent should have low levels of surfactants. The label should also indicate that the detergent is biodegradable. Surfactants are found in almost every laundry detergent because they help separate the body soil or oily stains from the fabric. There are two types of surfactants commonly used in laundry detergent - natural or oleochemical surfactants and synthetic or petrochemical surfactants. Oleochemical surfactants are derived from plant oils such as palm or coconut oil. Petrochemical surfactants are derived from crude oil. A detergent with natural surfactants will produce less sudsing and foaming than those with petrochemicals.

Septic Safe Laundry Detergents

After doing some research with septic system companies, including Wind River Environmental, this list of suggested detergents has been developed:

  • Arm & Hammer Laundry Detergent 
  • Charlie’s Soap Laundry Detergent 
  • Earth Friendly Laundry Products
  • Dr. Bronner’s Sal Suds
  • Equator 
  • Amway S-A-8 
  • Country Save Laundry Products 
  • Fresh Start
  • Biokleen Laundry Powder
  • Ecover Laundry Products 
  • Planet Laundry Products
  • Mrs. Meyers Laundry Detergent 
  • Mountain Green Ultra Laundry Liquid 
  • Seventh Generation Laundry Products 
  • Ultra Citra-Suds Natural Laundry Detergent

Septic tank safe laundry products can be more expensive than other detergents. If you are installing a new septic system or upgrading and prefer to use other detergents, then you should install a dry well beside the septic tank. 

While using the correct laundry detergent is a plus in keeping a system healthy, you must still be diligent in maintaining the efficiency of your septic system. The tank must be pumped out regularly and used properly.