The process of permanently disposing of fluid underground is also called Underground Injection. Wells are divided into five classes, from deep to shallow. Shallow injection wells inject or dispose of fluids into or above shallow aquifers and therefore pose a risk to water quality. Wells that are used for injection of hazardous waste are called "Class IV" wells and are prohibited. All other shallow injection wells, such as wells that are used for storm water, exterior vehicle wash water, sanitary waste, and other non-toxic fluids are included in the "Class V" category of injection wells. For detailed information on underground injection wells other than Class V, see https://www.epa.gov/uic.
Most commonly these shallow disposal systems are septic systems or dry wells, but any underground system that receives and permanently disposes waste would be considered a shallow injection well. A variety of names are used to describe shallow disposal systems including: cesspools, seepage pits, or improved sinkholes to name a few.
In 1999, EPA prohibited the use of shallow injection wells for the disposal of motor vehicle wastes. Such wastes include waste oil, fuel, brake fluid, antifreeze, soluble metals, and cleaning solvents. Even in small amounts, these substances have the potential to contaminate underground sources of drinking water. Operators of motor vehicle repair facilities, such as auto body repair shops, automotive repair shops, specialty repair shops (e.g., transmission and muffler repair shop), or any area where vehicular repair work is performed need to know where their waste flows. Fluids routed to a sewage treatment plant are not considered to be injected. Fluids routed to an oil/water separator or other device that terminates below ground surface are subject to the underground injection regulations.
For detailed information on underground injection wells other than Class V, see https://www.epa.gov/uic
Summary of Federal Requirements
Class V Injection Wells
Where the federal government directly implements the UIC program, Class V injection wells do not usually require a permit if they do not endanger underground sources of drinking water and they comply with other UIC program requirements including:
Class V injection activity may be authorized by rule, unless it violates one or more of the following standards:
- submitting basic inventory information about Class V injection, and
- constructing, operating, and closing Class V injection wells in a manner which protects underground sources of drinking water.
The owner or operator of an injection well that is authorized by rule must submit inventory information to the Director. EPA Form 7520-16 (Inventory of Injection Wells) can be downloaded here.
- it fails to comply with the prohibition of fluid movement standard in 40 CFR 144.12(a)] and described in 40 CFR 144.82(a)
- it is a Class V large-capacity cesspool or a Class V motor vehicle waste disposal well, both of which are prohibited.
Closing A Class V Well
When closing a Class V well, facilities must perform the following actions:
If the facilities' floor drains are connected to their septic system, the facility may be required to clean out the drains and the pipes running to the septic tank, seal them off using cement and have a licensed or certified septic service check the content of the septic tank to see if it needs to be pumped out to get rid of any contaminated sludge.
The facility may also be required to sample surrounding soils and ground water to insure there is no contamination. After this is done, the septic system can be used to manage wastewater from bathrooms.
Summary of State Requirements
States with UIC delegation must be as stringent as the federal regulations, thus have also prohibited motor vehicle waste disposal wells and large capacity cesspools. Industrial waste and stormwater injection are frequently required by states to obtain a discharge permit. Local onsite sewage, stormwater and ground water protection regulations may also apply.
To find out how to contact your state/federal Underground Injection Control program, please see https://www.epa.gov/uic
- notify the appropriate State or EPA UIC Director in writing 30 days prior to closure. EPA Form 7520-17 (Class V Well Pre-Closure Notification Form) can be found here.
- permanently plug or otherwise close the well in a way that ensures underground sources of drinking water are protected and is approved by your UIC Director
- dispose or otherwise manage any soil, gravel, sludge, liquids, or other materials removed from or adjacent to your well according to all Federal, State, and local regulations and requirements.
Summary of State Requirements
Some States may have more stringent requirements for motor vehicle waste disposal wells. For example:
- some States may ban motor vehicle waste disposal wells (not allowing owners or operators to apply for a waiver) while others may decide to apply the new motor vehicle waste disposal well requirements statewide, in which case, you must close your well or apply for a permit regardless of the location of your motor vehicle waste disposal well.
- If your floor drains are connected to your septic system, you may be required to clean out the drains and the pipes running to the septic tank, seal them off using cement and have a licensed or certified septic service check the content of your septic tank to see if it needs to be pumped out to get rid of any contaminated sludge.
- you may be required to sample surrounding soils and ground water to insure there is no contamination. After this is done, the septic system can be used to manage wastewater from bathrooms.
Laws and Statutes
The Safe Drinking Water Act