Deep Injection Wells

All injection wells more than 18 feet deep must have an approved injection well permit prior to use. Injection well permit duration varies based upon the well type and use, but 10 years is the maximum permit period. All permits to operate injection wells must be periodically renewed and a processing fee of $100.00 must accompany each application. All new deep injection wells must obtain an injection well permit and well construction permit prior to initiating construction of the injection well. A Notice of Completion of Construction must be submitted to IDWR upon completion of injection well construction.

Any modification to the construction, design, or operation of a deep injection well requires a permit. Typical modifications are increasing the well capacity or changing the nature of the injectate.

Injection well permits are assignable to new owners. Please notify the IDWR UIC Program regarding ownership changes for deep injection wells.

A deep injection well owner must notify IDWR following the permanent cessation of use. All deep injection wells that are to be permanently decommissioned shall be plugged with an impervious material in accordance with the Idaho Well Construction Standards to prevent movement of fluids into or between drinking water sources. Idaho law requires that decommissioning of all wells in Idaho to be completed with a permit by a well driller licensed in Idaho. A deep injection well owner must obtain approval from IDWR at least 30 days prior to the commencement of decommissioning activities, then notify IDWR within 30 days of completion of decommissioning activities.

Calculating Maximum Average Weekly Injection Rate

All deep injection well applications require the applicant to provide a maximum average weekly injection rate. The following guidance is available to assist applicants in calculating their injection rate.

Permit Processing Time

Processing a deep injection well permit normally takes a minimum of two months to complete. Please keep this in mind when developing project and construction timelines.

Permit Advertising

Public notice is required for all draft deep injection permits. This is done by posting a legal notice in a newspaper in the county in which the injection well is located. There also must be a period of at least 30 days following publication in the newspaper for any interested person to submit written comments and request a fact-finding hearing regarding the proposed injection well permit.

Ground Source Heat Pumps

Idaho Code (42-111 & 42-227) defines domestic water use and states that a water right is not required for domestic use, provided that the volume of water does not exceed 13,000 gallons per day. When permitting an injection well for a ground source heat pump, the UIC Program will determine if the use of a heat pump will cause a homeowner to exceed the 13,000 gallon per day limit for a domestic water right exemption. The following guidance is available for applicants to calculate their total domestic water use.

If domestic water use is anticipated to exceed 13,000 gallons per day, the applicant must obtain a water right as well as an injection well permit. For maximum efficiency, submit the injection well application to the UIC program at the same time the water right application is submitted to Water Allocations. UIC staff will process the injection well application, but not sign the injection well permit until the water right is approved.

Agricultural Return Water (Subclass 5F1)

Construction of new Subclass 5F1 injection wells that are likely to exceed the current ground water quality standard for coliform bacteria at the surface of a drinking water source directly below the injection well is prohibited. Applicants proposing to construct a new injection well to dispose of agriculture return water (5F1) are encouraged to discuss the project details with UIC Program staff prior to submitting an application.

Deep Injection Well Information

• Guidance for Calculating Maximum Average Weekly Injection Rate
• Guidance for Determining Total Domestic Water Use with a Heat Pump