Tritium in surface water

Fermilab map

Fermilab has conducted an environmental monitoring program on site for roughly 50 years. In November of 2005, for the first time, we detected low levels of tritium in Indian Creek, one of three creeks that travel through the Fermilab site. Low but measurable levels of tritium continue to be detected in the three creeks. All tritium levels found on site are well below the corresponding federal health and environmental standards.

The Department of Energy standard for surface water is 2,600 picocuries per milliliter, and our readings at the site boundaries to date have remained in the single digits. In our ponds, the levels are typically less than 20 picocuries per milliliter. The levels of tritium detected in the creeks and ponds on site are extremely low compared to what is safe for a lifetime of continuous exposure to tritium in surface water.

The low levels of tritium in the surface water on site stem from particle beams produced in accelerator tunnels. Water with low levels of tritium is pumped out of the accelerator tunnels and used in our cooling systems and ponds. Some of that water flows into the creeks on site. Samples are collected monthly at many locations on site to monitor this water flow.

The low levels we measure where the creeks leave our site are quickly diluted to undetectable levels as the creek gathers water from other sources. For example, the amount of tritium that Indian Creek adds to the Fox River is less than that added naturally by rainwater.

Fermilab regularly samples the water from Indian Creek, Kress Creek and Ferry Creek at least once per month when there is water flowing. The results of samples taken near the property boundary (indicated on the map) are posted on this site. In addition, we also report results taken in surface water onsite to the Illinois Environmental Protection Agency in compliance with our permits for surface water flowing offsite.

While low levels of tritium are expected to remain detectable in surface water on the site, Fermilab is actively working to keep levels as low as reasonably achievable. This web page contains more information about what we've done since 2005 to keep those levels low.

If you have any questions about tritium at Fermilab, please call the Office of Communication at 630-840-3351, or submit a question online.

Footnote: A picocurie is the unit used to specify how many tritium particles in a water sample decay into helium particles each second. Standard tests can detect levels of tritium in water that are larger than about 1 picocurie per milliliter. The Department of Energy surface water standards specify a limit of 2600 picocuries per milliliter.