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The Science and Hysteria of California’s Shade Balls

Did you catch that news story a few weeks ago about how Los Angeles is combatting its historic drought with 96 million black plastic balls? The idea is prevent excess water evaporation in the city’s main reservoir by blanketing the surface with lightweight plastic balls that are partially filled with water. In addition to preventing evaporation, they also block sunlight and ultraviolet rays that would otherwise cause excess algae growth. It’s an environmental two-fer.



The Los Angeles Reservoir has a capacity of 3.3 billion gallons, about a three-week supply for the city, and it loses about 300 million gallons to evaporation each year, an annual supply for 8,100 people. Thus, in a drought this severe, those 300 million gallons is worth fighting for.

The balls cost 36 cents each for a total cost of $34.5 million dollars. I hope the city got a bulk discount. To be fair, the $34.5 million investment helps offset the cost of treating the water to remove algae and other bacteria that accumulate in the presence of direct sunlight, which is estimated to be about $250 million.

Source: XavierC.

Source: XavierC.

Bonus: The balls were manufactured by the company XavierC, which calls them “conservation balls.” XavierC is a California-based, woman-owned start-up business that employs disabled vets.  Thus, the balls are made in the USA and as American as Bruce Springsteen.

This is what you get when you Google “Bruce Springsteen balls.” Source:

This is what you get when you Google “Bruce Springsteen balls.” Source:

The city of Los Angeles has been experimenting with the balls for a few years and determined that they reduce evaporation by up to 90 percent. Additionally, they are not expected to release toxic materials into the environment. The balls are made of high-density polyethylene (like your garden-variety gallon milk jug), which is fairly impervious to degradation; supposedly they will last for 25 years. Let’s hope the drought is over before then.

The idea for the shade balls came from Bird Balls, which are marketed by the EnQuip Company of Pennsylvania as having all the benefits of shade balls and the additional benefit of preventing unwanted birds from mucking about in a given body of water. This is especially important if the given body of water is toxic, such as a mining tailings pond.




The Inevitable Naysayers

According to Matt MacLeod, founder of the biotech start-up Modest Moon Farms, going with black balls “will form a thermal blanket speeding evaporation as well as providing a huge amount of new surface are for the hot water to breed bacteria. . . . It’s going to be a bacterial nightmare.” News source: Other experts agreed with MacLeod on the poor color choice. Naysayers believe that white or chrome-colored balls would be much better, due to their reflective properties.

Other experts believed that the whole “saving water” angle is a smokescreen for the real reason for the massive ball drop: Complying with new EPA guides that require public utilities to cover open-air reservoirs.

Sydney Chase, the president of XavierC, maintains that the balls are black due to the use of pure black carbon in the polyethylene. It won’t leach into the water, it’s non-toxic, and it blocks UV rays. Other colors would have required possibly more toxic dyes.

Hmmm. . . . pure black carbon. That doesn’t sound like anything I’d want mingling in my drinking water. Black carbon is the main ingredient in fine particulate matter; i.e., soot, produced when fossil fuels and organic matter are burned. It’s also “associated with premature mortality” and disrupts “global and regional climate.”

Okay. This gives me pause. Please, someone—don’t let me succumb to Fox News!

Science to the Rescue

Thank you, Bethania Palma Markus of Raw Story for providing a Daily Show-worthy smackdown to Fox News that fights hysteria with facts:

For perhaps the first time in its 113-year history, the Los Angeles Department of Water and Power has dedicated a press release to debunking the “bizarre theories” laid out in a Fox News story Thursday criticizing the department’s water conservation efforts.

The entire story, according to LADWP, was totally wrong.

I feel better already. Let’s continue:

The balls are keeping the water cooler, LADWP says. The “carbon black” surface makes them more structurally and thermally sound, and the air inside the balls acts as insulation, preventing any heat transfer from the sun to the water.

“Furthermore, the reservoir’s size and depth and flow-thru operations are able to keep the water cool,” LADWP responded. “In fact, our staff has verified that the temperature of the water flowing out of LA Reservoir is half a degree cooler than the water that goes into it after filtration and UV disinfection.”

I still didn’t quite understand how carbon black is supposed to be safe, so I dug up this reasonable explanation from Mika McKinnon at Carbon black is a

nearly-pure elemental carbon produced by burning hydrocarbons in an air-poor environment. . . . Carbon black can pose a health risk when it’s a powder by irritating lungs, but as a pigment it’s locked safely away. It is used worldwide in food packaging, and meets the NSF/ANSI 61 standards for materials that come in contact with drinking water. This means the balls won’t do anything nasty to the water supply they are protecting.

Thank you!

Furthermore, McKinnon says the balls are black because their purpose is “to provide shade, not to prevent evaporation. They block sunlight, so the ultraviolet light doesn’t catalyze nasty chemical reactions. . . . Cheap, thin-walled black balls still provide actual shade while lighter colours permit sunlight to penetrate into the water.”

I highly recommend reading the entire post. McKinnon’s explanation is a breath of fresh air and just one more reason why I love the Internet: For every crackpot out there, you can find a voice of reason. The crackpots may have the loudest voices, but reason speaks with a calmer voice of truth.

“Lone Ball Surveys His Domain.” Source:

“Lone Ball Surveys His Domain.” Source:





Posted on: September 18, 2015, 12:53 pm Category: Admin

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