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

Share this & earn $10
Veritasium
Published at : 3 months ago
36757288 views
468492 K
21802 K

I took a boat through 96 million black plastic balls on the Los Angeles reservoir to find out why they're there. The first time I heard about shade balls the claim was they reduce evaporation. But it turns out this isn't the reason they were introduced.

Huge thanks to LADWP for arranging this special tour for me. Next time let's put the GoPro on the submersible!

The balls are made of high density polyethylene (HDPE) which is less dense than water so they float on the surface of the reservoir even if they break apart. They are 10cm (4 inches) in diameter and contain about 210ml of water. So the main reason they are on the reservoir is to block sunlight from entering the water and triggering a chemical reaction that turns harmless bromide into carcinogenic bromate. This effect occurs with prolonged exposure to bromate so regulators insist that levels be kept below 10 microgram per liter on average over a 12 month period.

Special thanks to Patreon supporters:
Donal Botkin, Michael Krugman, Ron Neal, Stan Presolski, Terrance Shepherd, Penward Rhyme and everyone who provided feedback on an early draft of this video.

Thanks to:
Las Virgenes Reservoir for footage of initial shade ball dump
Euro-Matic for bird into jet-engine footage

Researched and Produced by Casey Rentz

Animations by Maria Raykova

Music from http://epidemicsound.com "Colorful Animation 4" "Seaweed"

And from Kevin MacLeod "Marty Gots a Plan"

This is an educational video about the science of water quality.
veritasiumblack ballsballsball pitshadereservoirblackplasticwaterLAlos angelesLA reservoirLADWPbromatebromidewater qualityalgaeevaporationwater supplychlorinesunlightsciencephysicscarcinogencarcinogenic
Advanced Agriculture Machines And Ingenious Harvesting Technology

Advanced Agriculture Machines And Ingenious Harvesting Technology

35 CEMENT IDEAS THAT ARE SO EASY

35 CEMENT IDEAS THAT ARE SO EASY

Top 10 Luckiest Shots in Golf

Top 10 Luckiest Shots in Golf

The workers could not imagine what this machine could do. - Crazy Construction Machinery.

The workers could not imagine what this machine could do. - Crazy Construction Machinery.

Amazing Agricultural Technology. -  Impressive Tractor Videos.

Amazing Agricultural Technology. - Impressive Tractor Videos.

Amazing monstrous whirlpool / Чудовищный водоворот / Dvietes atvars / Torbellino / Tourbillon

Amazing monstrous whirlpool / Чудовищный водоворот / Dvietes atvars / Torbellino / Tourbillon

Bill Gates's Lifestyle ★ 2017

Bill Gates's Lifestyle ★ 2017

Gravity Visualized

Gravity Visualized

Universe Size Comparison 3D

Universe Size Comparison 3D

[FUNNIEST ANIMALS  2019] Funny and Cute Animal Videos Compilation  2019 - Try Not To Laugh 2019

[FUNNIEST ANIMALS 2019] Funny and Cute Animal Videos Compilation 2019 - Try Not To Laugh 2019

Car Painting Ideas That Are On Another Level

Car Painting Ideas That Are On Another Level

World's Lightest Solid!

World's Lightest Solid!

Best Confusing Science Toys That Will Definitely Confuse You!

Best Confusing Science Toys That Will Definitely Confuse You!

Creative People Who Are On Another Level (Amazingly Satisfying) ▶3

Creative People Who Are On Another Level (Amazingly Satisfying) ▶3

How Microwaving Grapes Makes Plasma

How Microwaving Grapes Makes Plasma

AMAZING Science Experiments With Magnets - Oddly Satisfying Video

AMAZING Science Experiments With Magnets - Oddly Satisfying Video

10 Amazing Concept Cars From  FUTURE!

10 Amazing Concept Cars From FUTURE!

Lake Berryessa and the Glory Hole during and after drought.

Lake Berryessa and the Glory Hole during and after drought.

INTERESTING ROAD INVENTIONS THAT ARE ON AN ENTIRELY NEW LEVEL

INTERESTING ROAD INVENTIONS THAT ARE ON AN ENTIRELY NEW LEVEL

Woman Wears $13 Ring For 30 Years, Looks Again And Realizes She’s A Millionaire

Woman Wears $13 Ring For 30 Years, Looks Again And Realizes She’s A Millionaire

Street Food Vietnam - Fried Sticky Rice - Street Food

Street Food Vietnam - Fried Sticky Rice - Street Food

What's The Largest Thing To Ever Live On Earth?  DEBUNKED

What's The Largest Thing To Ever Live On Earth? DEBUNKED

Balls on escalator

Balls on escalator

Video shows moment dam gate collapsed at Lake Dunlap

Video shows moment dam gate collapsed at Lake Dunlap

10,000 Pennies Searched - What Did We Find?

10,000 Pennies Searched - What Did We Find?

Why Machines That Bend Are Better

Why Machines That Bend Are Better

This Mysterious Boat Washed Up On Ireland’s Coast, And There Wasn’t A Single Trace Of Any Crew

This Mysterious Boat Washed Up On Ireland’s Coast, And There Wasn’t A Single Trace Of Any Crew

Top 5 Underwater Discoveries YOU WONT BELIEVE EXIST!

Top 5 Underwater Discoveries YOU WONT BELIEVE EXIST!

Spotting at Robin Hood Airport - Then a Surprise! (PLEASE READ THE DESCRIPTION)

Spotting at Robin Hood Airport - Then a Surprise! (PLEASE READ THE DESCRIPTION)

SLIME BALL SHREDDING! SATISFYING VIDEO!

SLIME BALL SHREDDING! SATISFYING VIDEO!

Amazing Artificial Turf Machines That Are Next Level of Productivity

Amazing Artificial Turf Machines That Are Next Level of Productivity

Farmer’s Ancient 2 Ton Discovery Leads to Scientific Breakthrough

Farmer’s Ancient 2 Ton Discovery Leads to Scientific Breakthrough

After Largest Dam Removal in U.S. History, This River Is Thriving | National Geographic

After Largest Dam Removal in U.S. History, This River Is Thriving | National Geographic

Is Glass a Liquid?

Is Glass a Liquid?

The Most Extreme Black Holes In The Universe

The Most Extreme Black Holes In The Universe

Scientists have created edible water

Scientists have created edible water

Magnetic Micro-Robots

Magnetic Micro-Robots

Die 8 größten und TEUERSTEN Edelsteine, die je gefunden wurden

Die 8 größten und TEUERSTEN Edelsteine, die je gefunden wurden

Ancient Temple Of Crystal Skull Found In India?

Ancient Temple Of Crystal Skull Found In India?

Visiting the Royal Family of Dubai !!!

Visiting the Royal Family of Dubai !!!

World's Roundest Object!

World's Roundest Object!

Amazing THANOS gauntlet made out of 1,728 magnets

Amazing THANOS gauntlet made out of 1,728 magnets

The Discovery Of 'Vimana' secret 5000 years flying machine

The Discovery Of 'Vimana' secret 5000 years flying machine

Darker Than Vantablack—Absorbs 99.9923% of Light

Darker Than Vantablack—Absorbs 99.9923% of Light

11 REAL HOUSES Inspired by Cartoons | LIST KING |  10 real houses inspired by cartoons

11 REAL HOUSES Inspired by Cartoons | LIST KING | 10 real houses inspired by cartoons

I TOOK THE $3,000,000 LAMBO TO CARMAX! They offered me......

I TOOK THE $3,000,000 LAMBO TO CARMAX! They offered me......

14 Unique Proofs Asia is a New World

14 Unique Proofs Asia is a New World

Hoover Dam Will Be A Dead Cesspool By 2021 - The Coming Disaster Is Real

Hoover Dam Will Be A Dead Cesspool By 2021 - The Coming Disaster Is Real

What's inside Juggling Balls?

What's inside Juggling Balls?

Jared Leto Tour Guides Alaska's Melting Glaciers in 360°: Ready For 100

Jared Leto Tour Guides Alaska's Melting Glaciers in 360°: Ready For 100