In-Situ Recovery (ISR) is a form of resource recovery that is less intrusive than open-pit mining. ISR operations require specific geologic conditions, and also have different requirements for restoration after mining operations are complete.
Please see the FAQ below for some common questions regarding ISR, or visit our About ISR page for an in-depth explanation of the ISR process.
An aquifer is a geologic formation, group of formations, or part of a formation that is capable of yielding usable amounts of water to a well, spring, or other point of discharge. There are two basic types of aquifers: unconfined and confined. In unconfined aquifers, the groundwater only partially fills the aquifer and the upper surface of the groundwater (the water table) is free to rise and decline. A confined aquifer is sandwiched between two confining beds (layers of impermeable materials such as clay which impede the movement of water into and out of the aquifer). Because of the confining beds, groundwater in these aquifers is under high pressure. The high pressure causes the water level in a well to rise to a level higher than the top of the confined aquifer.
Uranium is one of the most abundant elements found in Earth’s crust, and it can be found almost everywhere – from soils and rocks to rivers and oceans. It is slightly more abundant than tin and 40 times more abundant that silver. Uranium was originally deposited on land by volcanic action over time, before being dissolved by rainwater and carried into underground formations. Eventually, the flow of underground water concentrates the uranium into ore bodies.
The goal of the mining process is to remove uranium from the aquifer and bring it to the surface for processing. The mining fluids must be kept in a confined area to prevent contamination of drinking water. Therefore, a confined aquifer is necessary to keep the fluids from migrating vertically. The facility must also demonstrate that it maintains hydraulic control on its wellfields to keep the mining fluids from migrating horizontally. To do this, facilities operate on a very slight “bleed”, meaning they pump out more fluid than is injected. This process creates a cone of depression around the mining area, in which groundwater within a certain area (determined by how strong the “bleed” is) changes direction to flow towards the well from every direction. This ensures that water flows towards the well and is pumped out, thereby preventing the spread of injection fluid beyond wellfield boundaries.
In order to operate an ISR uranium facility in Wyoming, a company is required to obtain up to 29 permits and exemptions from various federal, state and local agencies.
Nuclear Regulatory Commission (NRC) – Source and 11e.(2) Byproduct Material License
Environmental Protection Agency (EPA) – Delegates authority over Underground Injection Control (UIC) permits to the State Department Environmental Quality (WDEQ), final approval of Public Water Supply System permit
Bureau of Land Management (BLM) – Approval of the Plan of Operations, right of way permit for roads, and notice of intent to explore.
U.S. Army Corps of Engineers (USACE) – Verification of wetlands delineation and proposed mitigation measures
Wyoming State Land & Farm Loan Office – Uranium Minerals Mining Lease
Wyoming Department of Environmental Quality/Air Quality Division (WDEQ/AQD) – Air Quality Permit
WDEQ/Land Quality Division (WDEQ/LQD) – Permit to Mine, UIC Class III Permit and Aquifer Exemption, Wastewater Pond Construction Permit for the retention and sediment ponds, and the Mineral Exploration Permit/Drilling Notification.
WDEQ/Water Quality Division (WDEQ/WQD) – UIC Class I Permit and Aquifer Exemption, Permit to Construct Public Water Supply System, Permit to Construct Domestic Wastewater System, WYPDES Permit for surface discharge of excess permeate, Stormwater WYPDES Permit (industrial/mining), Stormwater WYPDES Permit (construction)
Wyoming State Engineer’s Office (WSEO) – TemporaryWYPDES Permit for discharge during well testing, Permit to Appropriate Groundwater for Monitor Wells, Permits to Appropriate Sufrace Water for Lined Retention Ponds and Sediment Pond
Crook County – County Development Permits for access road approach and emergency services agreeement