Private Wells Should Be Sited Far from Septic Tanks and Field Lines

Most rural homes use some types of septic system to treat household wastewater. These systems generally are economical and effective in treating these wastes. However, a septic system must be properly designed, installed, and maintained to reduce possible harmful impacts to the groundwater that supplies drinking water, neighbors' drinking water, or to surface waters such as a nearby stream.

What is a septic tank?

Septic tank is a tank typically underground, in which sewage is collected and allowed to decompose bacterial activity before draining by means of a leaching field. It safely treats and disposes of wastewaters produced in the bathroom, kitchen, and laundry. The system is used when sewage treatment plants are not accessible. The solids must be periodically cleaned from the tank to prevent blockage of field lines and subsequent overflow. With proper maintenance, a septic system can work efficiently for many years. The size of your tank, volume of your wastewater, and the amount of solids in your wastewater are factors that determine how often your tank will need to be pumped.

septic tank

Although a well-functioning septic system poses little risk to drinking water, a poorly operating system is a potential source of disease-causing bacteria, viruses, household chemicals, and nitrates. If significant amounts of any of these enter into drinking water, it could create health problems to you, your family, your pets and livestock, and even to your neighbors. A properly designed and functioning septic system breaks down harmful bacteria. In some cases, local conditions may keep a septic system from performing as designed.

As wastewater flows into the tank, the heavier solid materials settle to the bottom and form a sludge layer. The lighter greases and fats float to the top forming a scum layer, and the liquid flows out of the tank. Liquid in the septic system may flow to an area where water frequently pools near the surface, or the soil under the septic drain field may drain poorly. If this happens, the system may not completely treat wastewater and you may unknowingly "recycle" poorly treated wastewater into your home with your drinking water. An outlet prevents solids from flowing out with the liquids. The tank’s primary purpose is to retain the solids while releasing sewage effluent (liquid) to the drain field.

To avoid problems, install your septic system in an approved location and maintain it properly. Install a new or replacement septic system in well-drained sandy soil and as far as possible from your well, trees and plants. Pump out your septic tank regularly to keep it working smoothly and extend the life of the system. Your septic system will work better and need less maintenance if you reduce the amount of wastewater and solids, such as food wastes, paper towels, and other wastes, entering the system. Throw away these solid wastes in your household garbage.

What should not be flushed through a septic system?

  • Cooking grease, oils, or fats
  • Pesticides
  • Paints, paint thinners
  • Solvents
  • Disinfectants and other household chemicals

To protect your drinking water quality, locate your septic system and all potential contamination sources as far as possible from your well. Department of Health in many States requires that new septic tanks or human-waste lagoons to be installed at least 50 feet from a well. Septic tank drain fields must be at least 100 feet from a well. However, many health departments have different regulations so check your local health department for requirements applicable to your location. Although an existing septic system closer to a well may be safe, it is important to maintain these systems properly. Additionally, a septic system should also be far away from large trees and shrubs that can cause damage. State health laws also require all household wastewater, including sink, tub, shower, and wash water, to enter the septic system. Discharging household wastewater off your property violates state health laws. Before installing a new septic system, check with your county health department for any additional requirements.

As a general guidance, private wells which provide drinking water should have a minimum horizontal distance of 50 to 100 feet from such potential sources of groundwater contamination. It is recommended and sometimes required (depending on the state) that all wells providing drinking water be checked at least once a year for bacteria.

If a man’s home is his castle, then the surrounding land is his kingdom. It makes sense for people to care for their environment and nature in order to ensure that future generations will inherit a better world. Our planet is marvelous in its infinite beauty; the least we can do is to become a better caretaker!

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