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

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. Receive SMS online on sms24.me

TubeReader video aggregator is a website that collects and organizes online videos from the YouTube source. Video aggregation is done for different purposes, and TubeReader take different approaches to achieve their purpose.

Our try to collect videos of high quality or interest for visitors to view; the collection may be made by editors or may be based on community votes.

Another method is to base the collection on those videos most viewed, either at the aggregator site or at various popular video hosting sites.

TubeReader site exists to allow users to collect their own sets of videos, for personal use as well as for browsing and viewing by others; TubeReader can develop online communities around video sharing.

Our site allow users to create a personalized video playlist, for personal use as well as for browsing and viewing by others.

@YouTubeReaderBot allows you to subscribe to Youtube channels.

By using @YouTubeReaderBot Bot you agree with YouTube Terms of Service.

Use the @YouTubeReaderBot telegram bot to be the first to be notified when new videos are released on your favorite channels.

Look for new videos or channels and share them with your friends.

You can start using our bot from this video, subscribe now to Why Are 96,000,000 Black Balls on This Reservoir?

What is YouTube?

YouTube is a free video sharing website that makes it easy to watch online videos. You can even create and upload your own videos to share with others. Originally created in 2005, YouTube is now one of the most popular sites on the Web, with visitors watching around 6 billion hours of video every month.