Fermilab

Indian Creek results

Levels of tritium from various discharges associated with Fermilab operations into Indian Creek.

The graphs (click for larger version) show the levels of tritium from various discharges associated with Fermilab operations into Indian Creek. Monitoring the discharges has occurred continuously since November 2005, when our environmental monitoring program detected low levels of tritium in the creek for the first time in its 35-year history. State of Illinois agencies collected water samples from Indian Creek and confirmed the accuracy of Fermilab's measurements. The tritium levels are well below the federal water standards that Fermilab must meet. The detection limit is one picocurie per milliliter (see footnote below).

Fermilab monitors discharge to Indian Creek at state-permitted National Pollutant Discharge Elimination System (NPDES) outfalls and reports the results when they are flowing. Outfalls are flow-monitoring points where operational waters flow into waters of the state (such as Indian Creek). Primary Outfall 003 flows regularly, while secondary Outfalls 004, 005 and 006 rarely flow to Indian Creek. 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.

Fermilab routinely monitors 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 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.