Los Angeles Drops 400,000 Balls in Reservoir to Fight Suspected Carcinogen
by Jeremy Elton Jacquot, Los Angeles on 06.10.08
Image from Irfan Khan/LAT
Yes, only in Los Angeles, you might say. If you'll recall, I wrote a story a few months back about the discovery of a suspected carcinogen, bromate, in two large water reservoirs. The Department of Water & Power's (DWP) strategy at the time was: drain now, sweat the hard stuff later.
The new strategy, unveiled yesterday by DWP officials, is to dump hundreds of thousands of plastic balls onto the Ivanhoe Reservoir's surface (a reservoir adjacent to the Silver Lake Reservoir) to shade its water from sunlight. The reason for this rather unorthodox approach is simple: by blocking the sun, you prevent the reaction between bromide and chlorine, which forms bromate, from occurring.
The LAT's Francisco Vara-Orta has a nice account of the great ball drop (and a great set of accompanying pictures):
"At a signal from DWP General Manager David Nahai, a dozen crew members began opening dozens of white nylon bags that lined the terra cotta colored edges of the reservoir. Each bag bulged with 2,100 balls.
Resembling a slithering stream of oversized caviar, the black balls rolled thunderously down the reservoir's slopes. "Water quality doesn't get more exciting than this," Marina J.F. Busatto, a DWP biologist said, smiling, to a colleague as she helped slide ball-filled bags to the reservoir's edge.
Within 30 minutes, a portion cordoned off in Ivanhoe was blanketed with the black balls."
So why deploy these balls -- which are typically used by airports to prevent bird congregation on runways -- in particular? Some of the other alternatives, such as a large tarp or metal cover, were considered too costly or impractical. The balls, on the other hand, are (relatively) cheap -- costing 40 cents each -- and are safe for drinking water; black is also the only color able to deflect UV rays.
The DWP has ordered 6.5 million of these balls, 3 million of which it plans on using to blanket the Ivanhoe and Elysian reservoirs. So, yeah, this probably isn't the best solution for the city's water woes but, given the circumstances, maybe the only "realistic" option in the short-term.
Via ::Los Angeles Times: DWP drops 400,000 balls onto Ivanhoe Reservoir (news website)
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What happens when the balls get green with algae? They will have a nice green algae tea flavor.
Bromide and the attendant bromate are water purification items in the first place (the latter being a by-product of the former as noted in the article).
SO why are they using it? Have they stopped? And most importantly why are we adding carcinogens in the effort to make our water clean? Oxymoronic or just moronic?
probably kills all the aglea
It'll be a sad day when they find that the organic chemicals leeching from their plastic balls are as bad or worse than the bromate they are trying to get rid of.
There was an old lady who swallowed a fly?
I wonder what effect this has on evaporation. One would think it should reduce it, but probably not enough to justify the cost or it would be widely used. White balls would be better from a evaporation standpoint, less heating, but these might get lighter as water evaporates off of them and leaves calcium deposits behind.
And about the algae, if the reservoir is capable of support algae, it will have algae, balls or not.
And on the "why add bromide?"... They don't. The water already has bromide in it from its source. They just have to be careful to not let it react into bromate. That constrains what water sanitization process they can use.
Those are going to get hot hot hot
Won't the balls heat up as a result of their absorption of the sun's rays?
Won't the heat be transmitted to the water resulting in a much warmer (and therefore algae and bacteria-filled) lake?
Isn't most plastic carcinogenic...and the reason why we drink water out of our aluminum bottles rather than plastic?
Just throw some water hyacinth in it.
Remind me again how a gazillion black balls stop birds from landing on airport runways? News to be.
And yes indeedy, this sure will heat the lake up, but that doesn't seem to be the concern. Perhaps the surface coverage will negate the higher evaporation rates of warmer water? Either that or the moving balls will actually create more wet surface area and the lake will dry up lickety split. Hmm...
Birdballs prevent waterfowl from roosting in drainage ponds and waterways at airports.. thus keeping them away from low flying aircraft.
Looking at a couple of manufacturers pages, this actually looks like a well-thought-out, half-decent solution.
The bird balls apparently reduce algae growth (by blocking sunlight) and also reduce evaporation. I'd think keeping as much of the water around as possible in a place like LA would be pretty important.
The only real downside I see to this solution is that the balls are made out of plastic. Yuck.
I would have guessed the smog layer would filter most of the UV from reahcing the water ... interesting.
A little research suggests the balls are probably made of Poly Propylene, or possibly High Density Poly Ethylene, both of which are among the safer plastics out there.
You will have filamentous algal colonies on the balls - just as you would on the litoral zone rocks and sand.
...I guess someone really dropped the ball on this one.
they should use white balls to reflect the sun away, instead of black balls, which absorb more heat... lol
Thank goodness they didn't use blue balls.
when they take them out, I demand to see a ball pit consisting of 6.5 million balls!!!!
Shoulda covered it with those pontoon-based solar panels -- shade the water AND get power!
Jamie,
Most plastics are not carcinogenic. The ones we worry about are polycarbonates, and plastics that contain pthalates. Polycarbonates leach bisphenol-A, and plastics with pthalates leach the pthalates into water. Both of these are hormone mimics, not carcinogens.
As for whether the balls they dropped contain bisphenol-A, I don't think it is likely since polycarbonate is too expensive to use like that. I don't know whether they would have pthalates or not; that is a very good question.
Looks like a complete balls up however you look at it.
I've been writing about this for 3 months in my blog.
I just called the manufacturer of the balls and the NSF lab who tested the balls yesterday. According to the lab, the balls passed only one test: they won't leach into water that is 74 degrees.
No one knows if they will break down and leach from the UVF rays, the heat, cause heat and bacteria in the water, break down from age (4 years in the broiling LA sun is a pretty long time...) etc.
The HDPE plastic comes straight from the big oil companies, either Exxon or Chevron. The mfr. wouldn't tell me what grade of HDPE it is. The balls are from new plastic, and it is too expensive to recycle, so they won't be recycled.
Nice job, LA and Councilman LaBonge!
yikes! Does anyone know which parts of LA these resevoirs serve?? Filters, anyone?
Regarding the effect on evaporation, it seems to me like this would accelerate it. The balls will increase the surface area exposed to sun. As they slosh around they'll recoat themselves with water.