If you have enough space on your building lot, or if you live in a rural area, a septic system is usually a popular option for treating wastewater.

Instead of being connected to a municipal sewer line, a septic system independently treats a home's wastewater. The Department of Soil Science at North Carolina State University says a septic system can usually be installed on a one-acre building lot, as long as the soil is suitable for a leaching field.

Unlike a municipal system, however, a septic system is the sole responsibility of the homeowner. Failing to maintain the system or irresponsible use of your home's plumbing can result in damage to the septic system and several thousand dollars in repairs.

How it works

According to the Environmental Protection Agency, a septic system usually consists of four main components. There is a pipe from the house, a septic tank, a leaching field, and the soil beneath the system.

The pipe guides all wastewater from the home into the septic tank. This wastewater includes not only the material flushed down a toilet but also the water that is sent down the drain from baths, sinks, and washing machines.

The septic tank, a container buried in the yard, holds the wastewater for a time and allows some materials to separate out. Solids will sink to the bottom as sludge, while oils and greases will rise to the top of the liquid as scum. Naturally occurring bacteria will work to break down these materials. An outlet pipe brings the partially treated wastewater to the leaching field, and a screen on the pipe blocks this route to any solids.

The leaching field distributes the partially treated wastewater into the soil. The Connecticut Department of Public Health says the leaching field components are based on the type of soil around the house, but are often composed of stone-filled trenches or hollow structures surrounded by stones.

As the water leaves the leaching field, the soil acts as a filtration system. Bacteria, viruses, and other harmful materials are absorbed and eventually destroyed, purifying the wastewater before it reaches the groundwater. The soil can also make use of some chemicals such as phosphorus and nitrogen.

Installation and care

Prior to installing a septic system, a homeowner should have their soil tested to see if it is suitable for a septic system. Consulting with the local health and building departments will also give you an idea of whether your site is subject to any permit requirements or other considerations.

The NCSU Department of Soil Science says the leaching field is often located on gently sloping ground that has thick, permeable soil. Deeper water tables are also ideal for leaching field. The Connecticut Department of Public Health says the bottom of a leaching field should be located a minimum of 18 inches above the water table's seasonal high point.

The size of the septic tank and leaching field are dependent on the water use in your home. The more people and water systems in your house, the bigger your system will have to be. The leaching field should also be capable of operating during peak use and during times when it might have more difficulty draining, such as after heavy rain.

The flow of wastewater out of your home should not exceed the capacity of the septic system. You might have to expand the existing system if you are planning to renovate your home. The Connecticut Department of Public Health says homes serviced by a septic system require approval from both the local health department and local building department when adding onto a building, winterizing a home, renovating an existing space, or building an additional structure.

To prevent the sludge and scum from overflowing, the septic tank needs to be pumped out regularly. Taking this step every three to five years is usually sufficient, though more frequent maintenance may be necessary if you have a large family or heavy water use. Keep a record of where the septic system is located and when maintenance is performed.

Improving your water efficiency will take some of the strain off the septic system by reducing the amount of water entering the septic tank. Make sure the toilet's reservoir isn't leaking into the bowl and consider installing high-efficiency toilets and showerheads, low-flow faucets, and more efficient water-using appliances.

Keep an eye out for potential problems with the system. These signs include slow draining of toilets and sinks, a sewage odor, patches of lush grass above the septic system, and pooling of wastewater on the ground. Flooding in the leaching field often occurs after a heavy rain, when the leaching field is heavily saturated. Slow draining and clogs may be a sign of a plumbing problem, so the home's pipes should be checked before the septic system is inspected. However, the system should be checked without delay if sewage is backing up onto the ground.

What not to do

In general, you should not put anything in the wastewater system that you wouldn't put through your digestive system. Don't flush oil, grease, kitty litter, feminine hygiene products, or other materials down the drain or toilet. These items can clog up the septic system, requiring more frequent pump-outs or causing backups.

You should also avoid putting hazardous materials such as paint, paint thinner, gasoline, and pesticides down the drain. These materials will destroy helpful bacteria and microorganisms in the septic tank and leaching field, inhibiting the septic system's ability to break down solids and harmful materials in wastewater. Some chemicals can also leach through the soil and contaminate groundwater.

Moderate use of a garbage disposal is healthier for a septic system than heavy use. Since the ground-up material will be drained to the septic tank, cutting down on the use of the disposal will limit the amount of solids that settle in the tank.

Excess water should not be drained onto the leaching field, as this will limit its ability to drain wastewater into the soil. Direct gutter spouts, sump pumps, and other drainage systems away from the leaching field. The EPA recommends draining hot tubs and swimming pools onto the ground away from the leaching field rather than into the septic system to avoid overloading it and stirring up the solids in the tank. You can also look into possibilities for rerouting freshwater treatment systems, such as water softeners, to avoid having water unnecessarily pumped into the septic system.

Only grass should be planted above the septic system. The root systems of trees and shrubs could damage or clog the system.

Do not park any vehicles or other heavy objects on the ground above the septic system. The weight can compact the soil and reduce its drainage ability. It can also damage the pipes and other components of the system.