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Why Are 96,000,000 Black Balls on This Reservoir? — Transcript · YTtoTranscript

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Why Are 96,000,000 Black Balls on This Reservoir?

Veritasium · 2,438 words · 12 min read · EN

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Below is the complete, readable transcript of Why Are 96,000,000 Black Balls on This Reservoir? by Veritasium on YouTube. Read the full text, copy any part you need, or generate a transcript for any video with our free tool.

(shade balls rolling) - These are shade balls. They're being dumped into this water reservoir in Los Angeles. And contrary to what you may have heard, their main purpose is not to reduce evaporation. So what are they really for? To find out, I'm visiting the largest collection of these balls anywhere on earth, What?

at LA Reservoir. (tranquil music) 96 million shade balls. - [Man 1] That's correct. (laughing) - 96 million. It's very rare to for you to see 96 million of anything. - [Man 1] Yeah. (laughing) - This is your life vest which you are required to wear. - All right. - Throw a leg over and climb on in any way you can.

(tranquil music) There you go. - [Narrator] Thank you. Looking at this, I had so many questions. Like, why are they black? Are they safe to have in drinking water? How much do they cost? Do they actually reduce evaporation? And, what is their real purpose? (boat engine roaring) Is that hard to drive in shade balls?

- It is very hard. - Why is that? - 'Cause... (boat engine drowns James voice) - These are actually partially filled with water, and the reason they are filled with water is that, at LA Reservoir we have some really high winds and so, you know, if we didn't put water into these things,

there would be balls down bouncing on the 5 Freeway, people drive down, they'd be all over the place. So, these keep the balls in the reservoir and if they do start to roll, they kind of wobble because the water makes them uneven. - [Narrator] But that makes them significantly more difficult to push out of the way.

Especially, when they form close packed crystal-like structures. Behind the boat, the balls quickly come together in our wake. And some close to the motor are pulled along with the boat. (boat engine stopping) Wow! (wind blowing) (laughing) What did you think, the first time they suggested doing this or when it first came in?

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- Yeah, it was a little out there. - [Narrator] Did you think they were nuts? - No, not nuts. - [Narrator] Well, it just, it like looks absurd. It's like we're in the world's biggest ball pit. - Right, yeah, that's what it looks like. Yeah, you can't tell by standing here that we are actually floating

over, I think it's probably, 40 feet right here, 40, 50 feet deep below us, and you can't even seen any water. You'd think it was a joke, right? (laughing) If you didn't know, you'd go like, "No you're not, that's (laughing) a green screen or something, right? Yeah, its fake." - So like, when I switch on my tap at home,

is the water coming from here? - [Hellen] Yes. - Sometimes or always? - [Hellen] Yes, most of the time. - Most of the time? - [Hellen] Yes. - Most of the time the water is coming from here. - [Hellen] Correct, yes. - Absolutely nuts. So why is LA Reservoir covered in shade balls?

Well, the the problem all started with Bromide. - Bromide is a naturally occurring substance. It's associated with salt water and so normally places like California Aqueduct, that comes down from the Delta. You get some some salt water intrusions, so you have some Bromide in the water. Bromide's harmless and it's almost impossible to remove.

But, when you disinfect the water with Ozone, that Bromide becomes Bromate. And Bromate is carcinogenic. And so around the year 2000 they wrote regulations regulating Bromate. And the regulation basically said, if you have a treatment plant that uses Ozone, then you have to watch your Bromate formation. Be careful not to form too much.

So, the only places we ever measured Bromate was at our filter plant. - [Narrator] And the results were always within the 10 micrograms per liter limit set by regulators. So they were confused when they got a call from one of their customers, a beverage company in LA. - They said, "We have some really high levels

of Bromate showing up, are you aware of this?" And we said, "Well, we don't show anything." - [Narrator] But between the filtration plant and the customer was the reservoir. So they did some tests. - Almost immediately upon coming into to this open reservoir, the Bromate levels jumped. It turned out that Bromide with Chlorine,

which was supposed to be safe, in bright sunlight formed Bromate even more than Ozone did. And so we made the unfortunate scientific discovery that actually was not part of any regulatory scheme. And so, here we are at the reservoir, we have a water source that's got Bromide in it, harmless, we have chlorine, we have to have to disinfect the water

and we have sunlight because it's open. The only choice we have is to remove sunlight. So, we looked at all sorts of things. We looked at floating tarps across the water, and normally, you put a floating cover on the water but that's a multi-year project. And so we said, "Well, can we manufacture

these kind of trampoline with poly-like PVC pipe?" And we said, "Well, they'll just gonna become bird perches and we'll have a big water quality problem." Then we knew we had high-density polyethylene pipe, which is used in the water industry, and we know that it floats. We at one point thought about can we get float a pile of pipe across the surface.

Well, that's hard to do and very expensive 'cause it's a lot of material. So maybe we can take some pipe and we can run it through a chipper and we can make a debris field across the surface, like the back corner of a lake somewhere. But, then you have all this mushy, warm water

with plastic floating on the top and that however sounds like a Petri dish. And so low and behold, Dr. Bryan White, did some research and he found the shade ball. (tranquil music) - [Narrator] Except they weren't called shade balls at the time. (tranquil music) - This product existed and they were called bird balls

and they used it on ponds that had mine tailings, where they didn't want waterfowl to go in and get poisoned. And also around airports where there are ponds and they want to keep the waterfowl off so they didn't take off and get into jet engines. (airplane engine roaring) You know they have actually done wind tunnel testing

and they blew, you know, 50, 60 mile of winds across so they could see how they'd behave. But, they were really made to deter birds and wildlife from sitting on the water. - [Narrator] Did there used to be birds landing here more? - Absolutely, yes. - [Narrator] Yeah? - Yeah. Once we deployed these balls,

all the birds were gone. They used to just hangout, right? Loiter at the curbs. - Yeah, they'd be all over the top of the dam. - [Hellen] You could see birds dropping everywhere. - [James] They'd be down at the outlet tower, they'd be everywhere. We don't get 'em anymore like we used to.

- [Narrator] But before being added to the reservoir, the shade balls had to be tested. Would they actually reduce the formation of Bromate? - And we bought three kiddie pools, three little inflatable kiddie pools. And we filled them all with the reservoir water. One was in the sunlight, one we put a tarp on

and one put shade balls on. And amazingly, the shade balls knocked out the problem immediately. - [Narrator] So the reason shade balls are black is to block all light from reaching the water and triggering the Bromate reaction. The black pigment is also safe for contact with drinking water and it's stable even exposed to the elements for years.

- They're black for a reason so, you know, they're made out of a high-density polyethylene. It's the same material that like a gallon milk jug is made out of. It's a food grade plastic and they would be clear like a milk carton, except that they wouldn't last in the sun. And so, they have a material called carbon black in them

and that's what makes the plastic last for at least 10 years out in the sun. We did test to see if there is any other colors we could use. So we actually had the company make three different shades of blue, but the dyes were so unstable they said, "We can't guarantee it's gonna last more than a year."

And so, it's that carbon black that's the magic powder in this that really makes this product last in the sunlight. One of the concerns that people raised to me when we put first these on, it was that, are they gonna get hot and then bleach the material out? And they don't. They're totally inert.

I mean, theoretically, you could cut off a piece of this ball and you could chew it, no harm comes to you. This is totally food grade, nothing wrong with it whatsoever. - [Narrator] What's it like driving through these things? - It's difficult. As you can see we've been sitting here for, well, I don't know how long, quite a while,

and there's a breeze and we haven't moved. I mean anybody that knows, that's been on a boat in a lake, if there's a slight breeze and you're on a boat, you're drifting, right? Not here. This thing, they're just stable. They're (indistinct) It's interesting when you try to pilot the boat through these things, its difficult.

- [Narrator] It's like driving through peanut butter or something? - Or something, I guess, yeah. Not that I've ever done that but... (laughing) - [Narrator] Blocking sunlight from the reservoir also provided additional benefits. - You know, one of the reasons we put so much Chlorine was to control the algae growth. But sometimes you still couldn't control it.

There were times years ago, in the summer, where if we had an algae outbreak, you might actually, if you filled a bath tub up, you might have a slight tinge of green. I mean, it maybe healthy to drink, but it might have a slight tinge of green from the algae. - [Narrator] You'd see a bit of algae.

- Yeah, and it's just discoloring the water. That no longer occurs. So, with the sunlight gone, the algae problem is gone. We put in, basically, no Chlorine. We've only had a few times since the shade balls have been on LA Reservoir, that we've added any Chlorine at all. And we used to do half the Chlorine

and the whole water system went into that reservoir just to control algae growth. - [Narrator] But the big concern I had was evaporation. When I first heard about these black plastic balls reducing evaporation, it didn't seem to make any sense. I mean, wouldn't they absorb more energy and so heat up the water, leading to faster evaporation?

It turns out the answer is, no, for a number of reasons. In an open reservoir, there is more exposed surface area where water molecules can escape into the air. Plus, there is greater air flow over the water's surface continually removing the layer of moist air and replacing it with dryer air, increasing evaporation.

Now the shade balls do absorb more energy and get hotter on top, but the bottom of the balls stays cool. Plus the balls mostly contain air, which is a good thermal insulator and so not much of the heat is transferred through to the water. - It's almost like a double-paned window, you know, you get that air gap in there

and the air acts as an insulator, and so the sun never hits the water. Matter of fact, we've actually done some measurements and it's actually cooler under the shade balls, even though they're black, than it is without the balls, just with the sun itself. - [Narrator] Huh? - [Marty] So, the balls actually have a slight

cooling effect. - [Narrator] So, for all of these reasons, shade balls reduce evaporation by 80 to 90%. That's pretty significant for a dry climate like Los Angeles. - [Narrator] How much do they cost? - These run about, around three for $1. I think we paid 33, 34 cents a piece, something in that range.

And they actually will have a salvage value, not that much, but if we go to remove them, they are recyclable material. But we figured that over the life of the balls, between the savings in chlorination, is chemical savings, and the savings in evaporation, probably at least half the cost of the balls will be paid for.

I mean, of course, the water quality benefit is immeasurable, but even the balls themselves will save money doing what they do. - [Narrator] Do you ever bring people out here for tours? - You're the first one. (laughing) - [Narrator] Why am I the first one to get to go on a tour here?

- To get this level of detailed of tour, yes. - [Narrator] This is so cool! I've heard something about hexagonal balls, have you heard anything about hexagonal balls? - Oh, my gosh! So, we have the shade balls, and of course, everyone in the world came up with another product. I have ones I call se ravioli, it's a small hex.

We've got large hexes, we have all sorts of pieces. And people said, "Well, they lock together." But the problem is, they need to not stack up and they need to not sit on the bank of the reservoir. The reservoir is gonna go up and down. And so it was really the shape of the ball

that makes them not perch on the side because we need to make sure that these, when the water goes up and down, that they spread up, or they, you know, either spread out completely to cover the water as best possible. - [Narrator] I mean, I just can't get over what I'm seeing, it's just so nuts.

- I'm waiting for you to say it looks like a pool of boba. (laughing) - [Narrator] I feel like that's the line that'll go in, but you got it. Like, that is, that's awesome. Do you like boba? - I love boba. (laughing) I might get some after this. (laughing) (techno sound) (boat engine roaring)