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 “Colorful Animation 4” “Seaweed”

And from Kevin MacLeod “Marty Gots a Plan”

This is an educational video about the science of water quality.

Nguồn: https://vnecon.vn/

Xem thêm bài viết khác: https://vnecon.vn/tong-hop


  1. Redesign those ball's use Wireless energy transfer technology with Nintinol high output thermal electric generator's that generate electrical power and send it to Tesla coil's around the area to power lights and other devices used by the county to operate the facility.

  2. 🤣 in india to avoid water evopertae we plant lotus trees it will reduce evoporation and good strength to the soils..natural way..

  3. Do these balls biodegrade eventually? How will they be disposed of when they've outlived usefulness? That's a hell of a lot of plastic.

  4. I think it’s really interesting how they form crystals. In my eyes, they look like a metallic crystalline matrix! Which makes sense, because metal atoms behave pretty much the exact same way as those balls. They cling together, but are still malleable and can be manipulated. Most metals have springiness when you see them, and will spring back if you try to bend them. This is called “work hardening”, the atoms are all pushed together in a weird way from the milling or drawing process, and won’t hold a shape if bent. But if you anneal this metal by heating and quenching, it becomes what is known as “dead”. Which means the metal will just bend however you want it to and won’t spring back. Lead is a great example of a dead metal, it just bends like clay almost. These balls are definitely simulating the crystalline structure of a “dead” metal! Because they aren’t locked up in a gigantic perfect crystal, and can move however you want them to without cracking or immediately flexing back. Fascinating unintentional representation of atoms, and in my eyes it’s just another thing proving our hypothesis of what they are! A bunch of little particles that can only stack in certain ways, and will often form sloppy crystals because of external forces impacting them. If that water was perfectly tranquil, I bet they would form one giant perfect crystal! Just like keeping the beaker still when growing alum crystals at home! If you disturb it too much, the crystal gets messed up and weird looking!


Please enter your comment!
Please enter your name here