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Why are there 96 million black balls in this reservoir?

This reservoir in Los Angeles has been given the nickname "the world's biggest ballpit" as it now houses 96 million black balls. But what do they do? Why are they black? Surprisingly, the answer isn't to reduce evaporation!

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OK,   ill bite DREW,    i have NO idea,    WHY are there   90 millon black balls,  /?

Cats hit the play arrow -- it a bit long to explain in words

well, now i know,   thanks Plan B,  

The shade balls prevent bromate, a carcinogen, from forming in the water.

Back in 2007, the LA Department of Water and Power discovered it had a troubling water-quality problem. Its reservoirs contained a fair amount of bromide, which occurs naturally in groundwater. They also contained chlorine, which was being added to disinfect drinking water. When bromide and chlorine react with sunlight, they form bromate, a suspected human carcinogen. Not good.

Elevated bromate levels had been detected at the Silver Lake, Ivanhoe, and Elysian reservoirs. Mulling its options, the city decided it would shield some of its reservoirs from the sun. And shade balls were a low-cost option.

Next step: The city is also building a new indoor reservoir to replace Silver Lake and Ivanhoe — both of which had lots of contamination issues beyond bromate which include birds, runoff, and algae.

But what do you do when the rivers run dry ???

The Namoi River in north western NSW stopped flowing at the end of last year. It is unusual for the Namoi, but sadly the Namoi not alone in Australia.

I had one thought -- MORE PLASTIC

Also what about all the other water storage areas in the world?

You would think the blackness would drive up the water temperature making the puddle an organasmic eden.

 

OT.

All the photos of dry Australian river beds which all seem so shallow. I wonder how all the supposed megalitres get where they go.

Tests have shown the water temperature is actually cooler with the balls.

 

How about that, thanks Greg. Perhaps the sealed air volumes are providing significant insulation.

(Can't imagine swimming amongst them.)

You would think the blackness would drive up the water temperature making the puddle an organasmic eden.

 

OT.

All the photos of dry Australian river beds which all seem so shallow. I wonder how all the supposed megalitres get where they go.

Very interesting. Less Chlorine sounds good.

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