Underground Injection Control Program Overview
- Shallow Injection Wells: less than 18 feet deep
- Deep Injection Wells: greater than 18 feet deep
Rules & Statutes
Shallow Injection Wells
Shallow injection wells (SIW) in Idaho are those less than or equal to 18-ft deep. A SIW inventory form is required for every SIW in Idaho. This inventory form is where information regarding the owner, construction type, location, and nature of the fluid to be injected can be documented. A one-time processing fee of $75 is required to be submitted with each inventory form. For proposed SIWs, this form should be submitted prior to constructing the well. For existing SIWs the inventory form can be submitted after the fact. You may contact the UIC Program to determine if your SIW has been inventoried with the State. The SIW Inventory form and processing fee should be submitted to IDWR or the appropriate MOU partner in your area listed on the last page of the form. You can find the SIW Inventory Form as well as the SIW Criteria and diagrams of common SIW types below.
A shallow injection well owner must notify IDWR following the permanent cessation of use. All shallow injection wells that are to be permanently decommissioned shall be plugged with an impervious material. A shallow injection well owner must obtain approval from IDWR at least 30 days prior to the commencement of decommissioning activity and notify IDWR within 30 days of completion of decommissioning activities. There is no fee to decommission a SIW. You can find the SIW Decommissioning form below.
Partnership Opportunities
IDWR has partnered with local entities working to protect their local groundwater quality and continues to solicit additional partnerships. The mechanism for this collaboration is a Memorandum of Understanding (MOU) through which IDWR delegates authority to receive the SIW inventory form and processing fee from the applicant and periodically submit the SIW information to IDWR. Generally, MOU partners have a regional jurisdiction. All interested parties are encouraged to contact the UIC Program to obtain additional information regarding this opportunity. You can find the IDWR MOU Summary below.
Current IDWR SIW MOU partners include the City of Boise, the City of Hailey, the Panhandle Health District, and the Central District Health Department.
Motor Vehicle Waste Disposal Wells (Subclass 5X28)
A MVWDW is a type of injection well that receives or has received fluids generated during the repair and maintenance of motorized vehicles such as automobiles, boats, airplanes, locomotives, and recreational vehicles. During repair and maintenance activities, fluids such as fuels, oils, and solvents may spill or drip onto the shop floor and enter the injection well causing a degradation of the local groundwater quality over time.
One common MVWDW configuration consists of a floor drain or drains in a repair area that discharges directly to a drywell or a drainfield. Another common MVWDW configuration consists of a vehicle washing area where engine bay and undercarriage cleaning occurs over a drain to a drywell or drainfield. Oftentimes, a physical separator to remove oils, grease, and sediment is installed in the drainage pathway; however, its presence does not exclude the well as being a MVWDW.
Construction of new MVWDWs is not allowed and existing MVWDWs must be evaluated to determine potential sub-surface impacts due to its use. Please contact the UIC Program for assistance in determining if a feature qualifies as a MVWDW. For additional information, visit the Environmental Protection Agency’s Region 10 MVWDW Information webpage.
Shallow Injection Well Information
Shallow Injection Well Forms
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, and 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. To assist in calculating the injection rate, use the guide located in the Deep Injection Well Information section on this page.
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 (Subclass 5A7)
Idaho Code §§ 42-111 & 42-227 define domestic water use and state 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.
IDAPA 37.03.03.070.03.d(i) states that heat pump injection wells meeting specific criteria do not require a draft permit, are exempt from the 30-day minimum public comment period, and are not subject to a recurring permit cycle. The specific criteria that must be met to qualify for these exemptions are:
- Subclass 5A7 injecting heat pump outflow water only
- Well depth > 18-feet below ground surface
- Maximum average weekly injection rate of 50-gpm or less
A new application form has been created and is to be used for wells that meet the criteria outlined above. In addition to information regarding the well owner, well location, and well operation that has always been required on injection well permit application forms, this new application form requires additional information regarding the heat pump flow rate and square footage of the structure served by the heat pump.
Agricultural Return Water (Subclass 5F1)
Construction of new Subclass 5F1 injection wells that are likely to exceed the current groundwater 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.
Administrative Rules
Statutes
Deep Injection Well Information
- Guidance for Calculating Maximum Average Weekly Injection Rate
- Guidance for Determining Total Domestic Water Use with a Heat Pump
Deep Injection Well Forms
UIC Program Archived Documents & Records
The Environmental Protection Agency (EPA) signed the final rule revising the Code of Federal Regulations to reflect the voluntary transfer of the Class II Underground Injection Control program from Idaho to the EPA. The final rule was published in the Federal Register and made effective on July 30, 2018.