Groundwater contaminants

Some of the groundwater on the Hanford site is still contaminated. The risks to residents will increase if we do not continue to remove all contamination sources.

Workers hold up containers with groundwater samples at a cleanup pilot project.
Primary contaminants of concern include:
  • Uranium
  • Technetium-99
  • Iodine-129
  • Tritium
  • Carbon tetrachloride
  • Chromium
  • Nitrates
  • Strontium-90
All radioactive contaminants have the potential to cause cancer. Chemical contaminants can cause cancer and other health effects. At Hanford's 100 Area, along the Columbia River, strontium-90 has been a serious concern. In the past, it's entered the Columbia River at unacceptable levels.

As the diagram shows, when workers inject a phosphate mineral called "apatite" into the soil, it acts as a trap and separates the strontium-90 from the groundwater. This process of using apatite as a barrier prevents most of the strontium-90 from reaching the Columbia River.
Below are descriptions, health concerns, and exposure levels of radioactive isotopes and toxic chemicals found at Hanford.

Radioactive Isotopes

Cesium-137 Iodine-129 Strontium-90 Technetium-99 Tritium Uranium-238

Toxic Chemicals

Carbon tetrachloride Chromium Cyanide Nitrates Trichloroethylene