Underground Injection Well Registration in EPA's Pacific Southwest (Region 9)
EPA’s Pacific Southwest (Region 9) implements and enforces federal environmental laws in Arizona, California, Hawaii, Nevada, the Pacific Islands, and 148 Tribal Nations.
How to Register Injection Wells
If you own, operate or plan to construct one or more injection wells, you are required to register those features, also known as injection wells, with the Underground Injection Control program. This requirement applies to deep and shallow subsurface disposal systems as defined in 40 CFR part 144. Compliance with the federal Underground Injection Control (UIC) regulations includes fulfilling two basic requirements: (1) - register injection well(s) and (2) - do not use injection wells in a manner that will contaminate underground sources of drinking water.
These instructions and e-Form were developed to assist injection well owners in Arizona, California, Hawaii, and Indian Tribes of the desert southwest comply with the federal UIC regulations. Other state and local regulations may apply. See the regulations at 40 CFR part 144 for more information, at the U.S. Government Printing Office.
Frequently Asked Questions
My runoff discharges to a swale, pond or ditch. Is this injection?
If there is no subsurface (buried) discharge component to the system, then it is not subject to UIC requirements, however it may be subject to Clean Water Act requirements or other water protection regulations.
The injection well serves a single family home. Do I have to register the well?
Injection wells serving single family homes do not have to submit inventory information unless they are used by a home-based business, such as car repair, pet boarding, medical services or other businesses that generate a liquid waste stream that is to be disposed underground.
I have a septic system with multiple leachfield lines. Does each leachfield pipe count as a different injection well?
No, if all of the leachfields receive effluent from the same septic tank or other treatment device, they count as components of one injection well or subsurface fluid distribution system.
Is registering the injection well my only obligation?
Some injection activities are subject to state and local requirements and/or permits. Single-family onsite sewage systems are generally regulated by county environmental health agencies. Large capacity sanitary waste disposal and industrial discharges may be regulated by local or state water quality agencies. If your injection well(s) are subject to a discharge permit from the state, please list that permit number in the comments box to help reduce duplicative requirements.
Depending on multiple factors, such as your location in relation to drinking water supply wells or the type of injectate, your injection well(s) may be subject to additional federal requirements. These requirements may include sampling, characterization, permitting or closure of injection wells. Shallow injection of hazardous waste, untreated sewage and motor vehicle repair fluids is prohibited except in ongoing remedial actions overseen by regulatory agencies. See the regulations for more information. IMPORTANT: You must notify EPA if the ownership, well operating status or injectate changes.
How does EPA use the information?
EPA will use this information to notify you of applicable regulatory requirements or best management practices to prevent contamination. EPA shares the data with other water quality agencies, public water supply agencies, and in response to Freedom of Information Act requests for the data.
Do you need to register a drywell in Arizona with EPA?
Yes. EPA Region 9 directly implements the UIC program in Arizona. Drywells are shallow Class V injection wells and are authorized by rule as long as basic inventory information is submitted (see 40 CFR §144.26). ADEQ’s Drywell Registration Program ended on September 24, 2022 and new drywells in Arizona must be registered directly through EPA. To register a new drywell, fill out and submit the below Injection Well Inventory Form. ADEQ is transferring all existing ADEQ drywell registration data to EPA. If you have any changes to an existing ADEQ drywell registration, please fill and submit the below Injection Well Inventory Form; in addition, please select “Change” under the Transaction Type and note in the Comment section that the drywell has previously been registered with ADEQ. For more information on this transition, review the ADEQ Rulemaking FAQ Sheet (pdf).
For more information, contact your EPA or state UIC program or email R9iWells@epa.gov.
Injection Well Inventory Form
After submitting this form, a confirmation email with the submitted form data will be sent to the address provided.