Picture this with more balls: Nice, huh?
Picture this with more balls: Nice, huh?Courtesy Echo_29
Southern California is ball-crazy! Sure, everyone loves balls, from babies to seniors, but SoCal has brought it to a whole new level.

Los Angeles, in particular, is doing things with balls I’d never even thought of. They’re putting them in the water… by the millions! Millions of balls in the water, I guess, will make it better to drink.

The issue here is cancer. Or carcinogens—materials that can cause cancer. So the issue here is cancer.

Bromide, a naturally occurring ion of the element bromine, happens to be found in Los Angeles’ reservoirs. Bromine isn’t much to worry about on its own, but it turns out that the ion interacts with chlorine and sunlight (both of which are also found in the LA reservoirs) to form bromates, a group of chemicals that contain carcinogens. I couldn’t find a reference that explains it fully, but it looks like this is how it (basically) works: chlorine dioxide, the form of chlorine we use to treat drinking water, breaks down in sunlight into chlorine and oxygen. The bromide ions end up grabbing on to some oxygen to form BrO3, the bromate anion (“anion” just means that it’s a molecule with a negative charge). When that negatively charged bromate anion combines with a positively charged ion, a bromate is formed. And those are, as we’ve established, often bad. The combination of sunlight, bromide, and chlorine in LA’s reservoirs means that their water sources are becoming contaminated with bromates.

So thank goodness for balls, lots of balls. The Los Angeles Department of Water and Power means to solve the problem by removing sunlight from the situation. In about five years a huge underground reservoir should be finished, but until then LA has decided that the best way to block sunlight from the water is to cover it with millions and millions of black, plastic balls. They’ll float, and allow most things, but not sunlight, to pass through them. And they’ll look super crazy.

As we all know, however, you don’t just fill up a couple 10-acre reservoirs with balls in a weekend. Plus, the ball-making company can only produce about 100,000 balls a day, and there’s no doubt a great demand for balls beyond LADWP’s 6.5 million ball order. So this going to be a lengthy project. Over the next four years the Ivanhoe and Elysian reservoirs will be filled with about 3 million balls each. And then the underground reservoir will be ready. I expect there may be some spare balls around LA at that point.

Here’s more on the trouble with Bromates in drinking water.

And here’s more on balls.

Your Comments, Thoughts, Questions, Ideas

dlzc's picture
dlzc says:

This bromate photoproduction did not involve chlorine dioxide, but "liquid chlorine".

The US-EPA decided that bromate anion was a carcinogen based on potassium bromate studies:


... some of the target organisms were tested against potassium carbonate, and had the same cancer response. But "carbonate" is hardness and is present in all waters, so it was not called a carcinogen, nor did the US-EPA see fit to question their fiat against bromate et al.

Sodium bromate has been extensively tested, and has shown no carcinogenic behavior:


(Its a little dense... sorry.)

posted on Wed, 10/08/2008 - 2:33pm
JGordon's picture
JGordon says:

Thanks, dizc!

The article wasn't very clear, and I had to make some leaps. I wondered about that—I saw that potassium bromate is a carcinogen, but it was never mentioned if that was actually forming in the reservoirs. It's not, I guess? I appreciate the extra info.

Interesting, interesting...

posted on Wed, 10/08/2008 - 4:13pm

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