The shade balls are not necessarily a new invention to help solve our global water issues, they have been around for quite a while, but they have known by the name or “Bird Balls”, “Hallow Balls” or “Armor Balls”, and they have been used by the airports to prevent birds from nesting on the runways. The FAA approved them and it was such a good solution to their problem with wildlife that they are still using them today.
However, the novelty about these shade balls is that now, they are being used to prevent water from evaporation. The city of Los Angeles has coated its reservoirs in millions of black plastic balls, being the first city to use this type of innovation for water quality control. In a press release, the city claims shade balls are a “cost-effective way to reduce evaporation each year by nearly 300 million gallons, enough to provide drinking water for 8,100 people for a full year.” LADWP (Los Angeles Department of Water and Power) is the first utility company to use this technology and the deployment of 20,000 shade balls on August 10 marked the final phase of an effort that involved the deployment of 96 million shade balls into the 175-acre reservoir.
The balls cost 36 cents each, for a total of $34.5 million. Located in Sylmar, the reservoir holds up to 3.3 billion gallons, which is enough to supply the city with drinking water for up to 3 weeks. This project brings the LA Reservoir into compliance with new federal water quality mandates and is expected to save $250 million when compared to other tools considered to meet this goal. The shade balls will also prevent the annual loss to evaporation of about 300 million gallons of water. The utility has been testing the concept since 2008, reporting that shade balls reduce evaporation by 85% to 90%.
Shade Balls Used as a Health Prevention Method
Since this water was meant for public consumption, an emergency method was needed to reduce the amount of bromate to levels accepted by the health standards. On the other hand, the construction of another reservoir was approximated to take about four years to complete, but people could not afford living with a water shortage for such a long time. As far as the water storage facilities are concerned, the shade balls have also been used to cover the open reservoirs in LA since 2008. Because at that time the Ivanhoe Reservoir registered high amounts of bromate, they had to protect the water from the sunlight.
The solution proved to be very efficient because these shade balls, being spherical, would rotate and keep up with the water level and would also cover over 90% of the water surface, which was exactly what they were looking for.
In the midst of California’s historic drought, it takes bold ingenuity to maximize my goals for water conservation. This effort by LADWP is emblematic of the kind of the creative thinking we need to meet those challenges. Together, we’ve led the charge to cut our city’s water usage by 13%, and today we complete an infrastructure investment that saves our ratepayers millions and protects a vital source of drinking water for years to come.
Mayor Eric Garcetti
Shade Balls: Keeping Our Water Clean
Depending on their intended purpose, the shade balls have a ballast filling, which makes them weigh around 160g to 275g, and have a constant diameter of 4 inches. The amount of ballast keeps them 30% to 50% submerged, keeping them floating even on windy weather. The thick membrane cover is not affected by rain, snow or ice, and the special formula of polyethylene does not accommodate vegetarian growth on top, nor the formation of algae underneath the water.
They also serve as an air-water separation mechanism and keep the airborne dust, dirt and grime out of the water, which is another advantage of using them. If there is a lower amount of water or a lower amount of turbidity that has to be filtered, they ultimately save a lot of money out of pumping cost. Because all that water from a reservoir has to be filtered somewhere along the line and the cleaner the water is the less pressure it takes to drive it through their filters.
Shade Balls Reduce Global Water Evaporation
The 4 inches thick water cover acts as a shield against evaporation. By being used to separate the water from the heat of the sun, the average temperature of the surface water is going to be kept lower, and therefore, there is going to be less evaporation and you will save a lot of water. The manufacturers (XavierC, Artisan Screen Process, and Orange Products) say the balls should last about 25 years.
Many people have wondered why these shade balls are a heat-absorbing black instead of light-reflecting white. The purpose of those balls has nothing to do with keeping the reservoirs cool! They block sunlight, so the ultraviolet light does not catalyze bad chemical reactions. The balls are coated in carbon black, a food-safe pigment with an albedo near zero. Both these characteristics are vital in explaining why the balls are a dull light-absorbing black instead of a shiny light-reflecting white.
The balls are painted black because the color provides more protection than any translucent or opaque color would, as Sydney Chase, a spokeswoman for XavierC said.
After decades of testing, black has been deemed the color that provides the best protection. The other issue is sun protection — sunlight reflects right off the surface instead of penetrating through, like it would with translucent colors. The color concentrate is made of a certain material, and that also has to be tested to make sure it complies with drinking water standards.
Sydney Chase, spokeswoman for XavierC
Why Are Shade Balls Efficient?
It is a pretty good concept, they are inexpensive, and it surely makes a whole lot of sense to use them. The shade balls work best as air-water separation system when they are used to cover open reservoirs that have a nice concrete side to it and are of a clean geometrical shape, like a rectangular or even an oval. To learn more about how you can save water during these difficult times, contact us at 760.734.5787 and get in touch with one of our engineers.
Resources:
- http://news.nationalgeographic.com/2015/08/150812-shade-balls-los-angeles-California-drought-water-environment/
- https://gizmodo.com/why-are-drought-balls-black-instead-of-white-1724040253
- https://mashable.com/archive/los-angeles-reservoir-shade-balls
- https://www.ladwpnews.com/category/water-conservation/
