Uranium

GENERAL INFORMATION
Most drinking water sources have very low levels of uranium if shallow wells (under oxidizing conditions). Most uranium is naturally occurring, although contamination of drinking water sources from human-made nuclear materials can also occur. Most radioactive contaminants are at levels that are low enough to not be considered a public health concern.

HEALTH EFFECTS
Some people who drink water containing uranium in excess of the MCL over many years may have an increased risk of getting cancer.

Standard value 1: 
30.00
Standard units 1: 
ppb
Input units: 
ug/L
ppb
Contaminant group: 
Radionuclide
Standard type 1: 
MCL
Action is recommended 1: 

MCL ADVISORY - ACTION IS HIGHLY RECOMMENDED
Uranium levels were detected in your water sample to exceed the maximum contaminant level (MCL).

Action is optional 1: 

ACTION IS OPTIONAL
Uranium levels were detected in your water sample but do not exceed the maximum contaminant level.

Major sources in drinking water: 
Erosion of earth materials
Treatment options: 

TREATMENT OPTIONS

  • Anion Exchange: Anion exchange is a treatment system in which the well water flows through a tank with a resin that “exchanges” uranium for a safer compound – in most cases, chloride. Periodically, a backwash pump flushes the uranium and other wastes away from the resin into the household wastewater. The clean and recharged resin is then reused.
  • Reverse Osmosis (RO): RO uses a semi-permeable membrane to capture any uranium in the water. The device uses water pressure as a force against the membrane, and only water is able to pass through, which leaves the uranium behind. The membrane is continually rinsed. The rinse water containing uranium is discarded. This method of treatment can be slow and uses several gallons of water for each gallon of household drinking water produced.
  • Ion Exchange: Ion exchange removes approximately 90 percent of radionuclides. The effluent must be regularly monitored and the resin must be frequently regenerated to ensure that breakthrough does not occur.
  • Lime Softening: Lime softening is used on large water supply systems to soften water by the addition of calcium hydroxide. Calcium hydroxide raises the pH of water causing calcium and magnesium to settle out and form a solid sludge. 80 to 90 percent of the radium in the water becomes trapped in the sludge, which is removed by sedimentation and filtration. This process typically produces about 4 cubic yards (3.1 m3) of dewatered sludge per million gallons of processed water.
  • Coagulation/filtration: Coagulation and filtration is one of the most common water treatment techniques used by larger water systems, used for removing particulates and turbidity from surface water. A coagulant (typically either iron or aluminum salts with polymeric materials) is added and mixed with the influent water. The larger particles formed by coagulation are then removed from the water by filtration (typically sand, anthracite coal, or a combination of the two). Coagulation/filtration process has been identified by EPA as a “best available technology” for uranium. It may remove up to 90 percent of uranium at pH 10 and can also remove arsenic, iron, and manganese. It may be an attractive option for systems that already have a filtration process in place.
Website resources: 

WEBSITE RESOURCES

Fact sheets: 

FACT SHEETS