About 20% of homes in the United States use septic systems rather than being connected to a municipal sewage system to dispose of waste. However, in certain communities in New England and the southeast parts of the country, septic systems are used by nearly half of homes. Septic systems provide substantial benefits to the communities that use them. For example, septic systems are essentially individual wastewater treatment plants that reduce the need for municipal sewage treatment and the associated costs in money, clean water, and energy.
In broad terms, septic systems receive wastewater from the home into a septic tank. A septic tank can be made from steel, concrete, or plastic. A steel septic tank will not last as long (up to 20 years, on average) as a concrete or plastic septic tank (40 years or longer, on average). While the wastewater is in the septic tank, sludge sinks to the bottom, resulting in the removal of solids, and scum floats to the top. Good bacteria in the septic tank liquefy the solids and break down the scum. As more wastewater is added to the tank, an equivalent amount of effluent (wastewater excluding sludge and scum) is pushed out of the tank into distribution pipes. The distribution pipes carry the effluent to a drainfield, where the effluent percolates through rock and sand. The rock and sand naturally filter the effluent and the filtered water returns to the groundwater system.
Although septic systems are a natural form of wastewater treatment, they do require care and maintenance. For example, there are a number of ways that washing laundry can impact the effectiveness of septic systems. Here are four steps for minimizing the impact of washing laundry on septic systems:
Since wastewater flowing into a septic tank pushes effluent out of the tank and into the drainfield, less inflow logically means less outflow. A common problem with septic systems comes when the drainfield becomes saturated. A saturated drainfield cannot disperse effluent and can cause effluent to pool in the drainfield and wastewater to back up into the home.
A load of laundry can use anywhere from 14 to 20 gallons of water, depending on the size of the load and the type and age of the washing machine. All of this wastewater flows into the septic tank and pushes an equivalent amount of effluent into the drainfield. Conserving water, by spreading out laundry loads and setting the washing machine for the appropriate load size, not only reduces the water bill, but can also help avoid saturating the drainfield and causing wastewater to back up into the home.
Use Liquid Laundry Detergent
Powder laundry detergents can contain fillers that clog distribution pipes. Clogged distribution pipes cannot carry effluent to the drainfield and can cause wastewater to back up into the home. Liquid laundry detergent reduces the risk of clogged distribution pipes.
Minimize Harsh Chemicals
Harsh chemicals, like chlorine bleach and liquid fabric softeners, can cause “die off” of the good bacteria in the septic tank that are responsible for breaking down sludge and scum. After good bacteria die off, solids can accumulate in the septic tank, causing foul odors and clogged septic systems. Liquid fabric softeners also contain emulsifiers that can inhibit settling of sludge from the wastewater. Minimizing the use of bleach can reduce the chance of triggering a die off and using dryer sheets rather than liquid fabric softener can reduce the chance of interfering with settling of wastewater in the septic tank.
Clean the Washing Machine Lint Filter
Lint in the wastewater from a washing machine can cause clogs and blockages in septic systems. Some washing machines include lint filters. For those that do not include a lint filter, a lint filter can be installed in the drain line of the washing machine. Cleaning the lint filter will reduce the chance that lint will drain into the septic tank with the waste water.
Septic systems are able to handle most household wastewater. By taking a few steps, the impact of washing laundry on septic systems can be reduced.