Tap water
© Eric Thayer / Reuters
Almost 2 million people in California and the Midwest live on aquifer sites which have up to 180 times the safe level of uranium, according to a recent study by US researchers.

Some 275,000 groundwater samples were taken for evaluation, and it turns out that many Americans live about a kilometer from wells that are uranium-polluted, scientists from the University of Nebraska-Lincoln discovered.

Seventy-eight percent of the pollution comes from nitrate, the contaminator deriving from chemical fertilizers and animal waste. Nitrates oxidize uranium, making it soluble in groundwater. The aquifers are under the rich soil layer, which is fertilized by nitrates. That's when they get to the aquifers.

"It needs to be recognized that uranium is a widespread contaminant.

Comment: The problem is even bigger that that. The Israeli and US militaries frequently fire uranium-containing shells in the war zones they've created, and since then uranium radiation pollution has effectively spread around the world: UK radiation jump blamed on Iraq Depleted Uranium shells. History of uranium pollution:
  • In December 1995 and January 1996, U.S. Marine Corps Harrier aircraft training near Okinawa, Japan fired about 1,520 DU - depleted uranium - rounds. The Japanese government was not notified for almost a year.
  • In February 1999, two U.S. Marine Corps Aircraft expended 263 DU rounds at the U.S. Navy firing range in Vieques, Puerto Rico, which is not licensed for DU munitions. This "accidental" release was only discovered through a Freedom of Information Act request by the Military Toxics Project.
  • In January 2003, the Navy admitted routinely firing DU from its Phalanx guns in prime fishing waters off the coast of Washington state since 1977.
The people of Iraq (1991), Bosnia (1994-1995), Kosovo (1999), Afghanistan (2001-2003), Libya (2011) and Syria (2013) experienced uranium exposure first-hand:

Immediate battlefield exposures of combat and cleanup personnel to "depleted" uranium are only the tip of the toxic and radioactive iceberg. Continuing environmental exposures present a much longer-term danger to civilians in post-conflict areas. The Royal Society (the British national academy of sciences) recently concluded that because DU may move into the environment - especially water sources - over many decades, "contaminated land might be a concern for hundreds of years" and "contamination of water supplies or other sensitive components of the environment... might only become apparent after a number of years or more likely decades."

Firing of DU munitions can immediately contaminate air, soil, and water with ingestible particles of toxic and radioactive "depleted" uranium. (Read more in the original publication: "The depleted uranium fact sheet".)

And we are creating this problem by producing a primary contaminant that leads to a secondary one," co-author Karrie Weber, assistant professor of biological, earth and atmospheric sciences at the UNL, said, as quoted in the official press release.

The concentration in Great Plains (Midwest) measured up to 89 times higher than the standards set by the Environmental Protection Agency, while California aquifers proved to be even more contaminated, with 180 times the safe amount of uranium found there.

Drinking of uranium-polluted water can lead to kidney damage, elevated blood pressure. Food crops used in nutrition could also become contaminated by accumulating uranium from the groundwater.

The High Plains aquifer is the largest in the US, and it gives water to eight states, from South Dakota to Texas. The Central Valley, in its turn, provides for the California's most fertile agricultural regions.

All in all, the two aquifers in question give water to one sixth of the US cropland. "When you start thinking about how much water is drawn from these aquifers, it's substantial relative to anywhere else in the world. These two aquifers are economically important -- they play a significant role in feeding the nation -- but they're also important for health. What's the point of having water if you can't drink it or use it for irrigation?" researcher Weber said.

The research was published in the August edition of the 'Environmental Science and Technology Letters' journal. Part of the funding came from the US Geological Survey.