Tritium at Fermilab

Indian Creek results

The graphs (click for larger version) show the levels of tritium in Indian Creek between operational waters and the site boundary since November 2005, when our environmental monitoring program detected low levels of tritium in Indian Creek for the first time in its 35-year history. The tritium levels are well below the federal water standards that Fermilab is required to meet. The detection limit is one picocurie per milliliter (see footnote below).

State of Illinois agencies have taken water samples from Indian Creek in the past and confirmed the accuracy of Fermilab's measurements. Fermilab monitors discharge of operational waters to Indian Creek at permitted National Pollutant Discharge Elimination System (NPDES) outfalls. Monthly results are reported to Illinois EPA and have been included in the graphs. Outfall discharges combine with non-operational flow from tributaries before leaving Fermilab, further lowering the concentration (click on graphic).

Fermilab continues to monitor Indian Creek and the results are displayed on this page. A frequently-asked-questions page provides more information, and we have posted an aerial view of Indian Creek as well.

About the graphs: A solid dot appears on every day in which a sample has been taken and analyzed. Samples with no detectable level of tritium are represented by a solid dot on the line at the limit of detection (1 pCi/ml).

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.