Groundwater contaminants

Much of the groundwater on the Hanford site is still contaminated. Risks to workers and the public will be reduced by continued remediation activities.

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 and chromium have been a serious concern. In the past, these contaminants have entered the Columbia River at unacceptable levels.

As the diagram shows, when workers inject a phosphate mineral called "apatite" into the aquifer, 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

Toxic Chemicals

Carbon tetrachloride Chromium Cyanide Nitrates Trichloroethylene