The Idaho Water Resource Board’s Aquifer Stabilization Committee heard a presentation Tuesday from Idaho Department of Water Resources on the current permitting process of injection well programs in Idaho.
Officials said there is much work ahead, and revisions to the permitting process are potential outcomes from working groups with the Environmental Protection Agency.
Background
Injection wells are sites where surface water is injected into an aquifer, currently seen as a viable option for recharge of the Eastern Snake Plain Aquifer.
As previously reported by the Post Register, groundwater districts including the Bingham Groundwater District have sought to utilize them to offset required pumping reductions. Residents within the district have voiced concerns on the safety of these injection wells — as surface water itself can contain contaminants harmful to drink.
According to an email from IDWR officials, they have recharged over 2.9-million acre-feet — just under 2.5 Palisades Reservoirs’ worth of water — through canals, basins and wells over the past 10 years. With extensive monitoring, data has not shown any negative water quality impacts to the aquifer.
Last month, the Idaho Water Resource Board placed a “pause” on any additional applications for injection wells because of concerns from the public, to hear a presentation on the permitting process.
Current recharge injection wells not using agricultural runoff
During Tuesday’s Aquifer Stabilization Committee meeting, Erik Boe, water compliance bureau chief for IDWR, presented on the permitting process for injection wells.
Boe explained that IDWR has regulatory primacy of Class V injection wells — defined as sites that inject “non-hazardous fluids into or above underground sources of drinking water.”
Boe said managed aquifer recharge injection wells are classified as 5R21, and under this classification they can inject fluids from a variety of sources such as lakes, streams, domestic wastewater treatment plants, other aquifers, etc. Boe said an important distinction with these injection wells is they are essentially using river water routed through canals.
Boe said agricultural waste runoff injection wells, classified as 5F1, are not being considered for managed aquifer recharge. This injection well type would include drainage from fields, animal yards, feedlots, dairies, etc. While these injection wells were common years ago, Boe said they have not been permitted since around 2000.
“The reality is we do not allow agricultural waste runoff to be injected,” Boe said.
Boe said there are existing 5F1 injection wells, and they are allowed to be re-permitted with injection rate restrictions “to ensure there’s no points of re-diversion in the area of influence.”
Permitting process
Boe then detailed the lengthy permitting process for 5R21 injection wells. Applicants must adhere to both state and federal rules and laws.
During the process, the applicant is asked to demonstrate that the injection well will not endanger the underground source drinking water and will need to complete a monitoring plan. Upon review, IDWR will need to determine an area of influence — the area that could potentially be impacted by the injection well — and identify domestic wells within the area, which he said can be quite large at high injection rates.
The area of influence is determined based on the flow rate.
“It’s a very conservative calculation that we determine the area of influence related to that flow rate,” Boe said. “It’s not perfect but it’s actually quite conservative.”
Boe said IDWR requires domestic wells within the area of influence to be tested, though testing of certain wells can be waived if there are many wells in close proximity. In the monitoring plan, it will identify monitoring locations, frequency, contingency plans in case of a catastrophic event, and other items.
Testing frequency at wells is typically around two weeks, as it takes some time to collect and test samples.
Looking ahead
Boe said IDWR currently has a technical working group with EPA and the Idaho Department of Environmental Quality.
“We have formed a technical working group with EPA just to touch base, ensure that the permits for managed aquifer recharge injection wells are in compliance with federal code, and just to make sure that we’re all aware of the best-known practices,” Boe said.
Boe said outcomes may include changing how 5R21 applications are processed, updating permit conditions, implementing new spatial tools to determine whether managed aquifer recharge projects will impact source drinking water, and requiring applicants to provide site-specific information to demonstrate how it will not harm the aquifer.
“The public has reached out with a number of concerns related to managed aquifer recharge and injection wells that inject directly into the aquifer,” Boe said. “The EPA and the department of water resources take all these concerns very seriously.”
Boe said there have been few meetings for the working group. A board member asked Boe when outcomes might be expected working with EPA. Boe said he doesn’t have a timeline.
“How long it’s going to take depends on how long we have people still working at EPA,” said Albert Barker, another board member.
In recent days, as reported by many news outlets, the EPA has had staff changes following Trump Administration promises to overhaul federal agencies and spending.
“I don’t know if I’m going to have my EPA meeting this week,” Boe said. “It might be on hold a little bit. I have not heard from them over the last couple weeks.”
A press release from IWRB Wednesday stated “this will likely take several months.”