Tritium at Fermilab

Ferry Creek results

This graph (click for larger version) shows the levels of tritium in water between operational waters and flowing into Ferry Creek near the Fermilab site boundary since 2005. The detection limit is one picocurie per milliliter (see footnote). During droughts, Ferry Creek can be dry at the Fermilab site boundary, and we cannot take water samples.

Increased monitoring began on Ferry Creek following the detection of low levels of tritium in Indian Creek in November 2005. State of Illinois agencies have taken water samples from Indian Creek in the past, and comparing those results with Fermilab's results for Indian Creek confirmed the accuracy of Fermilab's measurement system. Fermilab monitors discharge to Ferry Creek at a state-permitted National Pollutant Discharge Elimination System (NPDES) outfall. Outfalls are flow-monitoring points where operational waters flow into waters of the state (such as Ferry Creek). Monthly results are reported to Illinois EPA and have been included in the graphs. Outfall discharges combine with non-operational flow into Sea of Evanescence before leaving Fermilab, slightly lowering the concentration.

The levels of tritium in the Fermilab cooling ponds and in Ferry Creek are well below the federal water standards for tritium. Fermilab continues to monitor the ponds and creeks on its site and take steps to keep the levels of tritium as low as reasonably achievable.

Fermilab will continue to display Ferry Creek monitoring results on this page. A frequently-asked-questions page provides more information, and we have posted an aerial view of Ferry Creek as well.

About the graph: A symbol appears on every day in which a sample has been taken and analyzed. Samples with no detectable level of tritium are represented by a symbol 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.