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Our INL Oversight Program (INL OP) conducts air, water, and terrestrial (soil and milk) sampling for a variety of radiological and nonradiological contaminants.

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Common Ions and Nutrients

Naturally occurring elements and compounds makeup 99% of all dissolved constituents in ground water or surface water, elements. These elements and compounds include calcium, magnesium, sodium, potassium, chloride, fluoride, sulfate, nitrate, phosphorus, and dissolved carbon dioxide. They also make up the vast majority by weight of dissolved contaminants disposed in wastewater at the INL. The ions allow an assessment of the overall health of the ground water.

Trace Metals

Trace metals are present at very low concentrations in ground water. These elements appear naturally but at very low levels. Chromium, zinc, and barium, were also disposed of in INL wastewater.


This man-made isotope is produced only in nuclear reactors and was historically released into the environment when wastewater was disposed of in ponds or wells. Technicium-99 decays with beta radioactivity.

Iodine-129 and Chlorine-36

Monitored in ground water, these are radioisotopes occur naturally at a very low level but were also produced during worldwide nuclear weapons testing. These isotopes are characteristic of INL wastewater and travel quickly with ground water. Tested for as part of special studies, these isotopes are generally present at very low levels (a million times lower than drinking water standards) and require special testing methods to see them at these atoms-per-liter levels.

Gross Alpha and Beta Radioactivity

The test for these types of natural or man-made radioactivity is a screening test, measuring contaminants or naturally occurring radionuclides that emit alpha and beta radiation. If measured radioactivity exceeds expected background levels or historic INL operations, then further analyses are done to identify specific radioactive isotopes.


A radioactive isotope of hydrogen that is most often found taking the place of nonradioactive atoms in water molecules. It is monitored in precipitation, water vapor in the air, and ground water. Tritium is made naturally in the atmosphere, can be created in nuclear reactors, and is present in spent nuclear fuel. This isotope gives off a low-energy beta particle and is not seen in a gross beta analysis.


One of the many isotopes created when uranium or plutonium undergo fission in a nuclear reactor. It decays with beta radiation.

Transuranic Radionuclides

Created in a nuclear reactor as a result of nuclear fission, transuranic radionuclides have more protons in their nuclei than uranium.  These radionuclides are monitored as particles captured on air filters and dissolved in ground water. Plutonium and americium are among the specific transuranic radionuclides that are monitored. Transuranic elements typically emit alpha-particle radiation and may also be seen with screening for gross alpha radiation or by gamma-spectroscopic analysis.

Gamma-Emitting Radionuclides

Monitored in air, precipitation, water, soil, and milk by examining the energy spectrum of gamma radiation given off by a sample. Cesium-137, Iodine-131, and naturally occurring Potassium-40 are a few isotopes specifically identified by their unique gamma-radiation energies.

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