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

  • Published on:  5/10/2019
  • 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 dumpEuro-Matic for bird into jet-engine footageResearched and Produced by Casey RentzAnimations by Maria RaykovaMusic 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.


  • polt 2 months ago

    Jesus christ, I finally watched it youtube are you happy?!

  • romanon5 9 hours ago

    Came for this comment

  • al7xx 15 hours ago


  • Anna Mae 2 days ago

    *It’s pretty rare to 96 million anything* Sand: am I a joke youLeaves: am I a joke you Dust: am I a joke to you Trees: am I a joke to you

  • Imperil a minute ago

    Atoms: am I a joke to you

  • david njenga a minute ago

    sperms duuu they in millions hihihi

  • Aditya More 22 hours ago

    Imagine playing golf with a black ball near this reservoir and ball falls into it

  • Nædrin an hour ago

    09:47 i dare you to attempt to say "matter of fact" faster than that.

  • Abhinav Bhardwaj 45 minutes ago

    🤣 🤣 🤣

  • Brian an hour ago

    Marty Adams - Chief Operating Officer, LADWP -- imagine if all government officials were as knowledgeable and explained problems and solutions as clearly. Very impressive. Thanks for making this video.

  • Tiznado 2 months ago

    Veritasium: It’s really rare to see 96 million of anythingSand grains: Am I joke to you?

  • lawomann 3 days ago

    @CONSPRIRACY REALIST Hey, if black balls clean our water, we use black balls. Nothing wrong with a simple solution, that's for sure.

  • SirDogeQ 22 days ago

    "It's pretty rare to see 96 million of anything"Pewdiepie : ...

  • Sharky Playz 3 days ago

    5:51 anyone else see that bird? Lol. RIP

  • Scott Mccullough 21 hours ago

    RIP Bird

  • Nædrin an hour ago

    Oh what? Shish i missed it.

  • koji kabuto an hour ago

    Wow, this was a perfect solution to a problem. Balls. LOL

  • Gabi Pina 2 days ago

    Water in L.A., keep throwing chemicals until you get cancer by drinking water. Fantastic job!Clap clap clap clap clap