Fear at the tap: Uranium contaminates water in the West

[WhiteTara]

http://news.yahoo.com/fear-tap-uranium-contaminates-water-west-051313046.html#

FRESNO, Calif. (AP) — In a trailer park tucked among irrigated orchards that help make California's San Joaquin Valley the richest farm region in the world, 16-year-old Giselle Alvarez, one of the few English-speakers in the community of farmworkers, puzzles over the notices posted on front doors: There's a danger in their drinking water.

Uranium, the notices warn, tests at a level considered unsafe by federal and state standards. The law requires the park's owner to post the warnings. But they are awkwardly worded and mostly in English, a language few of the park's dozens of Spanish-speaking families can read.

"It says you can drink the water — but if you drink the water over a period of time, you can get cancer," said Alvarez, whose working-class family has no choice but keep drinking and cooking with the tainted tap water. "They really don't explain."

Uranium, the stuff of nuclear fuel for power plants and atom bombs, increasingly is showing in drinking water systems in major farming regions of the U.S. West — a natural though unexpected byproduct of irrigation, drought, and the overpumping of natural underground water reserves.

An Associated Press investigation in California's central farm valleys — along with the U.S. Central Plains, among the areas most affected — found authorities are doing little to inform the public at large of the risk.

[Agnosticsherbet]

1. 100% natural uranium Umm-boy.

The real question is what can be done about the risk.
People must drink water.

[WhiteTara]

2. It's really a catch 22

drink water and die of uranium poisoning...don't drink water and die of dehydration. What a choice.

[Xithras]

3. The problem here is simple.

FYI, I grew up in Modesto. We were taught this stuff in our junior high science classes. While it's not exactly a secret, it's not widely discussed and more recent immigrants probably know nothing about it.


The problem is a simple one: The Sierra Nevada mountains are radioactive. All of them. Those pretty granite domes in Yosemite will set off even the cheapest geiger counter. The natural radiation levels are sufficiently low that they aren't an immediate health hazard, but there are spots with exposed uranium deposits that put even that assumption to the test.

The true floor of the Central Valley sits several thousand feet below the soil level we see today, and todays "ground level" is simply the result of millions of years of erosion washing those radioactive Sierra soils down toward the sea. The entire Central Valley is built on eroded uranium-tainted soil.

Historically, most California agricultural and drinking water came from surface diversions. There have always been wells in California, but until relatively recently (the past few decades) they were seen as an inferior water source and were typically only used in areas where surface water was unavailable. In places like Westport, well water has been used far longer, but shallow water tables (historically under 10 feet) meant that the water pulled from those wells had only been underground a short time and was still relatively clean.

Between population growth and drought, surface water has become increasingly unavailable over the past few decades and our dependence on well water has increased dramatically. Water tables have plunged hundreds of feet in some areas, and the water being pulled now is "deep water". The article blames it on leaching from agriculture, which certainly plays a role, but the simple truth is that many in the Valley are now drinking deep water that has been sitting in that radioactive soil for thousands...or even tens of thousands...of years. Because uranium is a heavy element, uranium tainted water has tended to settle deeper into the soil over the eons. Every winter, for millions of winters, the flood cycles have rinsed the uranium deeper and deeper into the soil...into the deep aquifiers that we're increasingly coming to depend on in this area. That water carries all sorts of natural minerals (including uranium) that simply aren't present higher up.

There is no real solution to this problem short of eliminating wells completely. You can educate people about it, but then what? The prices for uranium removal systems START at around $70,000 and climb into the millions. You can still buy entire houses in parts of the Valley for less than $70,000, and nobody is going to put in a water filter that costs more than the house its protecting. This is one of the poorest areas in the nation, and there are hundreds of thousands of water wells sitting behind houses and out in fields that would need to be retrofitted. Having the state subsidize the construction of filters for privately owned wells is going to be a political nonstarter.

Ultimately, the problem can only be avoided by finding new water sources for the Central Valley, and building the infrastructure to pipe those sources where it is needed. When the need for well water is eliminated, the dangers that come along with using our wells will be eliminated too.

[KamaAina]

4. "The entire Central Valley is built on eroded uranium-tainted soil."

That would be the Central Valley where much of the country's fruits, nuts and veggies are grown, right?

[Igel]

5. Very low concentrations.

We're talking about the uranium concentrations in igneous rock. It's going to be leached out of the weathered particles that form the inorganic base of the soil and then concentrated in the lower strata of the soil, far from the prying roots of small, herbaceous plants. So the drinking water is much more dangerous than the soil. Even then, it's not a huge problem unless that's really your only source of drinking water.

Probably not a huge uptake by those plants, even if the concentrations were higher. It's the metal's toxicity has a heavy metal that's at issue here, not really any radiation.

[Xithras]

6. The very same.

Whether or not its a problem depends on the source of the water used to grow it. The biomass of a plant is mostly made up of water and of carbon structures built with CO2 pulled from the air. While some nutrients are sapped from the soil, the amounts are trivial in comparison to the size of the edible fruits. The amount of uranium in the soil is low, and the amount of that soil pulled into a plants biomass is also low, so the soil itself is going to contribute an immeasurably small amount of uranium to the food grown here.

Water is a different story though. The article mentions Westport school, which I'm actually familiar with (I used to drive down Carpenter road past that school every day). The water at Westport is considered unsafe for human consumption. Across the street from it is an orchard that is irrigated via a local canal, filled with surface water diverted from the nearby Tuolumne River. The water in those canals, and going into those trees, is much safer than the well-sourced tapwater in that elementary school. The fruit and vegetables grown with that water is going to be clean and healthy.

The same can't be said for other orchards and farms a hundred miles south that are 100% dependent on wells for their survival. Most of the Valley well water is still within safe limits, but not all of it. If a farm is pumping well water that contains uranium levels that exceed what you can safely consume, and they're putting that water into their crops, the crops will end up containing unsafe uranium levels too. It's unavoidable.

Nearly all food grown here is safe to eat, but some is not. The problem for you, the consumer, is that there's no real way to tell the difference.

[closeupready]

7. This must be part of why cancer rates are so high in California.

Or rather, higher in comparison with polluted cities on the East Coast. I always thought that was weird; I think this sheds some light on that.