Introduction: What is an Abandoned Septic Tank?
A septic tank is a sewage treatment system used for both domestic and industrial use. Household septic tanks are traditionally located outside the building’s main sewer line, while waste water from industrial facilities is typically piped to a septic tank. The tank can be used as a primary or secondary (back-up) wastewater treatment process depending on its size and design. Septic tanks are commonly used for residential purposes in the United States, Mexico and Australia, but are also used in the United Kingdom, Canada and New Zealand. Septic tanks may also be used as secondary wastewater treatment systems for water supply networks. 
A diagram of a conventional septic system, showing the large underground tank. Note that the size of the tank is not to scale.
A conventional septic system consists of an underground tank for holding wastewater, and a cover for protection from outside influences (such as dust, or vehicles driving on top). The tank is generally a concrete or plastic cylindrical silo with an inlet in its bottom. On top of this is a filtering layer and drainage layer. Either a concrete sump pumping station, or a lift station, is positioned on top of the tank. The discharge pipe can be connected to the drain in the home, or directly to a septic tank truck.
What You Need To Know About Buying A House With An Abandoned Septic Tank
A septic tank is not a home’s only source of wastewater disposal. The property may also have a drywell, a leach pit, and/or an absorption field. If these other components are present on the property, they could help to reduce the burden on the septic system. However, these other areas may also be overloaded as well. Overloads in septic systems may also come from extreme weather conditions and increase the chances of backup into the main sewage lines. 
A septic tank is a deep, vaulted, bowl shaped container that contains wastewater in the form of leachate. The general purpose of a septic tank is to store and treat human sewage before it is eventually disposed of by the surrounding soil or water. In some cases, septic tanks are used to store animal waste as well. According to the EPA, a septic system should be designed properly so that it can handle all wastewater being sent into it when it is in good operating condition (i.e. room for all the fluid in the tank and an effective way to get rid of it safely). 
Conclusion: Resources To Find Out If There Is An Abandoned Septic Tank On Your Property
In order to find out if your property has an abandoned septic system, it is recommended that you first check for a well in the backyard. If you do have a well on your property, it is important to check with the local government to see what plans have been made. In some cases, all of the homes in the area and the septic system must be checked before they can be drained. If you know of other homes in your area that have a septic tank, there are places that can help you check if they are still functioning. These places include the local health department, the state health department, and local search engines. Depending on where you live in the country, there may also be an organization that can provide you with further information about your septic tank.
The resources that are available in your area will also be very important. If you do have an abandoned septic system in your backyard, it is recommended that you first contact a local health department to see what they recommend. Some counties will be able to provide information about who to contact and how to proceed. For example, there might be a place like a state health department that can provide you with information about who is responsible for the septic system.