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 am visiting the largest collection of these balls anywhere on Earth
at L.A. reservoir.
96 million shade balls?!
It’s very rare for you
to see 96 million of anything.
This is your life vest which you are required to wear.
Throw your leg over and climb on in anyway you can.
There you go.
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?
James Tilch 洛杉矶水电局 维护与建设人员
Is it hard to drive in shade balls?
It is very hard.
Why is that?
These are actually partially filled with water.
And the reason they’re filled with water is that
in L.A reservoir we have some really high winds.
And so, you know, if we didn’t put water in these things,
there’d be balls 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 kinda wobble
because of water makes them uneven.
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.
Did you… what did you think the first time
they suggested doing this or when they first came in?
Yeah, it was a little out there.
Did you think they were nuts?
No, not nuts.
Well, it just… it like, it looks absurd.
It’s like we are in the world’s biggest ball pit.
Right, yeah, that’s what it looks like.
Yeah, you would, you can’t tell
by standing here that we’re actually floating
over I think it’s probably 40 50 feet right here, 40 50 feet deep below us.
And you can’t even see any water.
You’d think it was a joke, right?
If you didn’t know,
you would be like, no you’re not,
that’s a green screen or something, alright?
Yeah, it’s fake.
So like when I switch on my tap at home,
is the water coming from here?
– Sometimes, or always? – Most of the time.
– 偶尔是 还是大部分时间都是？ – 大多数时候都是来自这里
– Most of the time? – Yes.
– 大部分时间？ – 没错
Most of the time the water is coming from here.
So why is LA reservoir covered in shade balls?
Well the problem all started with Bromide.
Bromide is a naturally occurring substance associated with salt water.
And so normally places like the California aqueduct that comes down from the Delta
you get some salt water intrusions
usually has some bromide in the water.
Bromide is harmless
and it’s almost impossible to remove.
And but when you disinfect the water with ozone,
that bromide becomes bromate.
And bromate is carcinogenic.
And so around year 2,000
they wrote regulations regulating bromate.
And the regulations 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 place we ever measured bromate was at a filter plant,
and the results were always within the 10 μg/L limit set by regulators.
So they were confused
when they got a call from one of their customers,
a beverage company in L.A..
“We have some really high levels of bromate showing up.
Are you aware of this?”
And we said, “Well, we don’t show anything.”
But between the filtration plant and the customer was the reservoir.
So they did some tests.
Almost immediatly upon coming into this open reservoir,
the bromate levels jumped.
It turned out that bromide with chlorine which was supposed to be safe
in bright sunlight form bromate even more than ozone.
And so we made this unfortunate scientific discovery
that actually was not part of any regulatory scheme.
And so, here we are at the reservoir.
We have water source that’s got bromide in it. Harmless.
We have chlorine, we have to have disinfected water.
And we have sunlight because it is 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 put a floating cover on the water,
but that’s a multi-year project.
And so we said, well,
can’t we manufacture this kind of trampoline with poly,
like PVC pipe.
And we said, well, they’re just gonna become bird perches,
it’ll have a big water quality problem.
And so, 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 to float a pile of pipe across the surface.
Well, that’s hard to do and very expensive,
because it’s a lot of material.
So maybe we can take some pipe and run it into chipper.
We can make it a debris field across the surface,
like the back corner of a lake somewhere.
But anyhow all this mushy warm water with plastic floating on the top
that sounds like a petri dish.
And so lo and behold
Dr Brian White did some research
and he found the shade ball.
Except they weren’t called “shade balls” at the time.
This product existed
and they were called “bird balls”.
And they will use 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 were ponds
and they wanted to keep the waterfowl off
so that they didn’t take off and get into the jet engines.
You know they’d actually done wind tunnel testing,
and we had… we blew you know 50 or 60 mile hour wind’s across,
see how they’d behave.
But they are really made to
deter birds or wild life from sitting on the water.
Did there used to be birds landing here more?
– I feel like… – Absolutely!
– 我感觉…… – 绝对有很多的
Yeah, once we deployed these balls, all the birds were gone.
是的 放进这些球后 所有鸟都不见了
They used to just hang out, right?
Loiter at the curbs.
– Yeah they’d be all over the top of the dam. – You see bird droppings everywhere.
– 没错 鸟原来都在那边 或是水坝上 – 到处都能看见鸟粪
They’d be down at the outlet tower.
They’d be everywhere,
but we don’t get them anymore like we use to.
But before being added to the reservior,
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,
one we put shade balls on.
And amazingly the shade balls knocked out the problem immediately.
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 are made out of 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 milk carton,
except that they wouldn’t last in the sun.
And so they have a material called “carbon black” in there,
and that’s what makes the plastic last for at least 10 years out in this sun.
We did test to see
if there is any other colour 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 is the magic powder in this,
that really makes this product last in the sunlight.
One of the concerns that people raise with me when we first put these on
was that are they gonna get hot and then leach material out.
And they don’t. They’re totally inert.
I mean theoretically, you can cut off a piece of ball, and you can chew it.
理论上 你可以切下一片 然后咀嚼它
No harm comes to you, this is totally food-grade.
Nothing wrong with it whatsoever.
What’s it like driving through these things?
As you can see,
we’ve been sitting here for a while, how long?
Quite a while.
And there is a breeze, and we haven’t moved.
I mean anybody that knows that’s been on a boat in a lake,
if there is a slight breeze and you are on a boat, you’re drifting, right?
如果有微风 船会漂动的 对吧？
Not here. This thing, they are just… stable. They don’t move.
在这里不会发生 船很稳定 不会动
It’s interesting when you try to pilot the boat through these things.
It’s just difficult.
– It’s like driving through peanut butter or something? – Something, I guess, yeah.
– 有点像在花生酱里开船吧？ – 我猜是有点像吧
Not that I’ve ever done that.
Blocking sunlight from the reservoir also provided additional benefits.
You know, one of the reasons that we put so much chlorine in
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 algae outbreak,
you might actually, if you filled the bath up,
you might have a slight tinge drink.
It may be healthy to drink,
but it might have a slight tinge green from the algae.
You can see a bit of the algae.
Yeah, and just discolouring 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 put on in LA reservoir,
they’ve added any chlorine at all.
And we used to do half of the chlorine in the whole water system within that reservoir,
just to control the algae growth.
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 enery 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 surface
continually removing the layer of moist air
and replacing it with dryer air,
Now, the shade balls do absorb more energy
and get hotter on top,
but the bottom of the balls stays cool.
Plus the balls contain mostly air,
which is a good thermal insulator,
and so not much of the heat is transferred through the water.
It’s almost like double pane 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 is actually cooler around the shade balls,
even though it is black
than it is without the balls just with the sun itself.
So, the balls actually have a slight cooling effect.
So for all of these reasons,
shade balls reduce evaporation by 80 to 90 percent.
That’s pretty significant for a dry climate like Los Angeles.
How much do they cost?
These run about around three for a dollar.
I think we paid 33, 34 cents a piece, something in that range.
So… and they actually have a salvage value,
not that much,
but if we go to remove them,
they are recyclable material.
So… but we figure that over the life of the balls
between the savings and chlorination, is the chemical savings
and savings in evaporation,
probably at least half of the cost of the balls would be paid for.
And so, I mean of course the water quality benefit is immeasurable,
but even the balls themselves
would save money doing what they do.
Do you ever bring people out here for tours? or…
You’re the first one.
Why am I the first one to get to go on a tour here?
To get this level of detailed tour, yes.
This is so cool!
I’ve heard something about hexagonal balls.
Have you ever thought about the hexagonal balls?
Oh my Gosh, so we had these shade balls of course,
天啊 当然听说过了 我们用上遮阳球后
everyone in the world came up with another product.
I have once I called “ravioli”, it’s a small hex.
We had large hex, we had all sorts of pieces,
and people say would 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’s gonna go up and down.
And so it’s 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 spread out completely to cover the water as best as possible.
I mean I just can’t get over what I am seeing.
It’s just so nuts.
I’m waiting for you to say
it looks like a pool of boba.
I feel like that’s the line that’ll go in.
But you got it, that is…
– Do you like boba? – I love boba.
– 你喜欢珍珠奶茶吗？ – 超喜欢的
I might get some after this.
These are shade balls.