Important reason 96 million black plastic balls were released into reservoir

Have you ever wondered how many plastic balls it would take to cover the surface of a reservoir? Well now you don't have to.

Over the past decade authorities in Los Angeles have been adding black plastic balls into various reservoirs across the state.

Now before you get too excited, it's important to point out that the state of California isn't attempting to create a giant ball pit with this venture.

In fact, the project actually has its roots in water conservation and environmentalism.

First being implemented back in 2009, the Los Angeles Department of Water and Power deposited around 400,000 of these balls into a reservoir, with the project originally scheduled to last around five years.

This looks like it would be fun to jump in. (YouTube/ Veritasium)

Are shade balls safe to put in sources of drinking water?

In a video uploaded to YouTube by Veritasium's Derek Muller, he explained that shade balls were originally created to prevent the creation of a carcinogen (which can cause cancer) called bromate.

Muller explained that bromide - a natural substance found in sources of salt water - can often find its way into sources of drinking water.

Bromide on its own isn't harmful to humans, but once it comes into contact with the ozone treatment used in US drinking water it makes the carcinogenic bromate.

This process is also intensified when the water comes into contact with sunlight.

Taking a boat out into a sea of plastic balls does look pretty fun. (YouTube/ Veritasium)

Are there other benefits to shade balls?

While the original use of the balls was to prevent creation of bromate in the water, LA officials soon discovered there were also environmental benefits to having water sources shaded from the intense sunlight often found in California. "Shade balls reduce evaporation by 80 to 90 percent," Muller explained. "That's pretty significant for a dry climate like Los Angeles."

It has since been reported that the shade balls have led to savings of around 1.1 billion litres of water a year.

Why are the shade balls coloured black?

Now you may be wondering if black - a colour which is notorious for absorbing heat - was decided upon by researchers, and there is an exact reason for this.

The balls get their colour from a dye called carbon black and is not only safe to come into contact with drinking water but also stable to leave in the reservoirs for several years.

"[Carbon black] is what makes the plastic last for about 10 years out in the sun," Marty Adams, Chief Operating Officer for the LADWP explained, adding that tests of other colours were tested but found to be too 'unstable' to use alongside drinking water.

So if you've ever been confused by the sight of millions of plastic balls floating in the baking LA sunlight there you go.

Just don't jump into them thinking it's a giant ball pool.