URANIUM MINING AND RECOVERY OPERATIONS INFORMATION
"We live in an unscientific age in which almost all the buffeting of communications and television - words, books, and so on - are unscientific.
As a result, there is a considerable amount of intellectual tyranny in the name of science." (R. Feynman, 1968)
The purpose of
this website is to provide scientific information regarding uranium mining.
The goal is to identify misinformation and provide accurate, scientific information.
We do NOT advocate for or against mining.
This project was
initiated in August 2007 and the information here is expected to increase as it is screened and
This page was created as an ongoing compilation of scientific research.
Since it is unusual for people to have training in radiation safety and a proposed uranium in situ
leach project is located approximately 5 miles from concentrated population areas, this webpage is
an ongoing compilation of the scientific research that has been done and is being done regarding
uranium mining. It is difficult to separate the rhetoric from the scientific information.
The Health Physics faculty, who has formal training in radiation
safety and are well aware of the radiation risks associated with uranium mining, hopes the information on this page will assist thoughtful people in this process.
This page is provided as a service of Colorado State University and is produced by the Health Physics
faculty and the Colorado State University Student Branch of the Health Physics Society.
What is ISL or ISR mining? (non-technical description)
Millions of years ago uranium was dissolved (solubalized) in water. As this water moved
underground the oxygen within the water was consumed (probably by bacteria and other organic matter),
causing the uranium to settle out (precipitate).
In situ leach mining (ISL or in situ recovery mining, ISR) reverses the process that caused the uranium to settle out. This
is done by pumping water mixed with oxygen and carbon dioxide through the uranium deposits via wells.
In order to reverse the process that caused the uranium to settle out (precipitate) the water that is
pumped into the deposit has oxygen added.
However, if only oxygen is added to the water, the same
processes that used up the oxygen in the past will use this new oxygen again, and the uranium will
not move very far before it re-settles out.
Adding CO2 suspends uranium in water
Adding CO2 (carbon dioxide) to the water in addition to
the oxygen keeps the uranium from coming out of the water. If you have ever had a soft drink,
you are familiar with carbon dioxide in water - that is what makes the bubbles in your drink!
When the water and uranium mixture is pumped to the surface, the uranium is "filtered" out
(via an ion exchanger) and the oxygen and carbon dioxide replenished so that the cycle can repeat.
The "filter" (ion exchanger) is taken away for processing once it is filled with uranium.
The removal of oxygen from the water millions of years ago also caused other metals to settle out.
These metals include arsenic and selenium. Naturally, these metals will also get into the
circulating water as well. The mining process does not generate these metals. They circulate
with the water as they remove uranium.
Miners are very careful when performing this process, since their profits rely on keeping the
uranium in the water that they remove. If there are any leaks, they would immediately begin losing
money, and with uranium worth almost $100 a pound, you can imagine the controls they have! Since
they must control the uranium in order to make a profit, the environment is also incidentally
Leaks are a major loss of profit, and also an environmental concern. Multiple tests
are performed on wells to make sure there are no leaks. Additionally, miners test nearby wells
frequently, with instruments that are so sensitive they can detect the gravity from the moon,
just like the ocean's high and low tides!
After the uranium is removed the goal is to return the ground to low oxygen conditions. This will
cause the metals, including selenium and arsenic, to settle out again, and return the ground to
In the past this was done using various methods, but today the solution that
is injected is one of the favorite food groups: Sugar! The sugar is pumped into the ground to feed
the bacteria that live there. The bacteria feed on the metals (selenium, arsenic, and any leftover
uranium) and cause them to settle out again. It is thought that these are the same type of bacteria
that used up all the oxygen millions of years ago, and are using it up again.
Next, alcohol is pumped in to assist the bacteria in removing the last of the oxygen from the
ground. Off the record, many in the mining industry say "first we feed the bacteria
and then get them drunk!" This method seems to work much better than those used in the past, and is popular because it is
very cheap and effective.
Who checks the water for cleanliness?
So who checks the water to make sure the miners cleaned it up? The state regulators verify that the
water has been restored so that it can be used for the same things as it could be prior to the mining.
The regulators must be satisfied, or the mining company will forfeit a bond, usually worth millions
of dollars. The value of the bond is set by the regulators prior to the beginning of mining operations.
Since the regulators work for the state, there is no downside to them rejecting
anything that does not meet standards.
ISL process not complex
Overall, the ISL process appears difficult to understand, and uses language like "lixiviant" for the
water mixed with oxygen and carbon dioxide. The reality is that it’s not too complex. The
people operating ISL mines are usually cautious and careful in the job they do and have welcomed
genuinely concerned visitors to operating sites. They have been willing to show the precautions they
take, and are concerned about their workers and environment. At one mine with a staff of 100
employees, 15 people are in the environmental and safety department!
Mining using ISL does change things, but the resulting radiation doses to the public are so low that
they are difficult to measure, the underground water is locally altered but can still be used as if
the mining had not occurred, and the long term surface impact appears to be minimal.
All documents are in PDF format unless otherwise noted.
Documents and Links
- The following two links are to the University of Wyoming, Energy Resources and Produced Water Conference held in May 2010:
- Groundwater Restoration at Uranium In-situ Recovery Mines, South Texas Coastal Plain, Susan Hall, USGS (pdf)
- Hydrological, Geological and Biological Site Characterization of Breccia Pipe Uranium Deposits in Northern Arizona
- This link is to an environmental assessment at an ISL uranium mine in Wyoming in 2006 by the
USNRC. The document gives an overview of the environmental impact of ISL mining. The restoration of
the groundwater after mining is presented on pages 23 and 24. Also, page 25 presents information on
the one "excursion" that occurred during the previous years, the results of that excursion and
corrective action. The impacts to local wells is also on page 25.
- Standard Review Plan for In Situ Leach Uranium
Extraction License Applications
- Guidebook on Environmental Impact Assessment
for in Situ Leach Mining Projects
- NRC Regulatory Guide 4.15, Quality Assurance For Radiological Monitoring Programs
(Inception Through Normal Operations To License Termination) - Effluent Streams And The
- NRC Regulatory Guide 3.46, Standard Format And Content Of License Applications, Including
Environmental Reports, For In Situ Uranium Solution Mining
- Scientific evidence exists that challenges the statements made in
paragraphs 3, 4 and 7 of the Larimer County
Medical Society resolution.
Links to those scientific, peer reviewed studies are below.
Peer reviewed studies links
- The Colorado Mining Association letter
accurately represents the cited literature.
- The rights of surface owners is not an area where we have expertise, but some interesting
information is available from the state regarding these rights
at this website.
- Colorado School of Mines Office of Special Programs
and Continuing Education.
A good source for scientific information on uranium toxicity is the
ATSDR (Agency for Toxic Substances and Disease Registry, a part of the US Department of Health and Human
Services, under the Center for Disease Control.
Their complete profile for uranium is linked below. The "Public Health Statement" portion of the
document is an excellent overview of uranium. A key statement made in the document is on page
"No human cancer of any type has ever been seen as a result of exposure to natural or
ATSDT Report on Uranium toxicity 1999
Aquifer Restoration at In-situ Leach Uranium Mines: Evidence for Natural Restoration
Methods of Minimizing Ground Water Contamination from In Situ Leach
Uranium Mining NUREG/CR-3709
Uranium Mill Ore
Dust Characterization EML-384, 1980
Human Uranium Studies
During the late 1800's and early 1900's, uranium was used to treat the symptoms of diabetes. As a
result, several papers were published on the effects of uranium that was ingested (eaten) by humans.
Two of those studies are linked below. We apologize for the poor quality reproduction of some pages.
There are many additional later uranium studies that we will post as we obtain permission.
Further contribution on the treatment of
diabetes mellitus by uranium nitrate
by West, S. British Medical Journal, August 1895.
Remarks upon the value of uranium nitrate in the control of glycosuria by Bond, C.H.,
The Practitioner, September 1898.
Watch or download the video of US
NRC Generic Environmental Impact Statement Meeting on In-situ Mining and
Milling, held in Casper WY, August 7, 2007. William Von Till from USNRC provides an overview
of in-situ mining. Requires Windows Media Player.
Department Contact Information:
Environmental and Radiological Health Sciences
1681 Campus Delivery
Fort Collins, CO 80523
Phone: (970) 491-7038
Fax: (970) 491-2940