The Skeptical Environmentalist #1: Are “shade balls” the last hope for California’s water?

Image by Amber Case |

Image by Amber Case |

'The Skeptical Environmentalist' is a series dedicated to the critical analysis of specific environmental initiatives, projects, and ideas to evaluate the associated benefits, setbacks, and optimal solutions for the issues at hand. 

When we think about large-scale geo-engineering, we likely imagine the more permanent (or at least virtually irreversible) methods of changing the environmental features of our biosphere, such as shooting aerosol particles high into our atmosphere to mitigate the effects of a warming climate. Such initiatives strike much controversy, even among prominent environmentalists – and understandably so. There are dozens of potential unintended consequences that could occur, not to mention the ‘unknown unknowns’ – adverse events we are not even able to fathom and thus cannot account for in the planning phase of such projects. 

But what about temporary and reversible means of modifying the environment for our direct benefit? That’s exactly what has been happening in California. 

In response to the severe ongoing drought, California has settled on an unorthodox approach to help protect the water remaining in the Los Angeles Reservoir: releasing a plethora of plastic balls into the water bodies. And by plethora, I mean 96 million of these ‘shade balls’, as they are dubbed.  (See video here).

Why I’m skeptical:  On one hand, this is pretty innovative. (Fun fact: these balls were previously used to keep birds away from airport runways; it is fairly obvious that birds and planes don’t mix).  But considering our society’s mixed environmental ethics, how exactly should we morally interpret this initiative? 

Certainly, releasing tens of millions of plastic balls into a body of water is not expected to have the same appalling shock value as permanent geo-engineering initiatives (plastic balls in water can be removed when desired; aerosol particles shot into space cannot).

Regardless, this remains an anthropogenic modification of a natural environment, which raises a big question: What degree of ecological intervention is acceptable, particularly in such desperate times? Water levels are alarmingly low and at risk of evaporation and contamination, but will human intervention really make things better in the long run? In cases like this, are short-term ‘Band-Aid’ fixes acceptable and effective? Given that these shade balls can be removed at any point (albeit likely at a very slow rate), should we maintain the same level of skepticism about manually manipulating our environment to sustain human demand? Do projects like this become less taboo if they can be reversed just as quickly as they were put into place? 

In addition, we know that certain types of plastic can cause some undesirable health effects in humans and wildlife. I’m skeptical that there are no health risks associated with tossing 96 million plastic balls into a reservoir.  

Well, the science behind this decision appears to check out. All of the shade balls are black, which prevents (or at minimum, decreases) evaporation of the valuable remaining water by denying the sun the ability to turn the liquid water from the reservoir to water vapour (or gas).  The balls are also designed to protect the water from dust and toxic chemicals (including carcinogens), the harmful effects of which may be amplified without the contribution of dilution from a larger reservoir (We know that the phrase ‘dilution is the solution to pollution’ is no longer considered effective environmental management, but dilution can still play some role in water quality).

The most pressing question for me is: What happens to 96 million polyethylene balls after they are removed from reservoirs? Are they delivered and reused elsewhere? What if we find there to be unintended consequences of these seemingly harmless objects? How do we dispose of them properly? (One source claims that after 10 years of use, the balls are recycled, but it is unknown to what degree they are recycled, and what can be done with the remaining materials).

We know that plastic is not easily degradable. Polyethylene is considered a ‘safe’ plastic, unlikely to release carcinogens or other harmful chemicals into the environment, though this is not to say that the amount of polyethylene used to cover the total surface area of 96 million balls does not pose any risk, particularly given that they are in direct contact with water that Californians rely on for drinking. It would be quite ironic to learn that shade balls pose health risks of their own, while one of their main purposes is to eliminate carcinogens from the water.   

This also is not the first time California has used this technique to protect its water. In 2007, the Ivanhoe Reservoir was covered with 400,000 shade balls. However, the imminent threat in this case was high bromate concentrations, the result of bromide, chlorine, and sunlight – the latter of which was eliminated from the equation by releasing black polyethylene balls into the reservoir.   

Skeptic’s final thoughts: Though I am not fully convinced that there is no chance of potentially harmful toxicants leaching into the water from the vast quantities of plastic used, I understand the need for this degree of anthropogenic manipulation of the environment on the basis that the means are temporary and reversible when no longer necessary. That being said, there may also be unintended, long-term consequences of even temporary environmental management practices, and these should be noted. Given the planet’s changing climate, we are likely to see more of these eyebrow-raising projects in the near future. In terms of inefficient water use practices, though, California could very well take the cake. An abundance of luscious lawns and water-intensive almond orchards are just two examples of things that maybe shouldn’t be happening in an area with limited water to begin with. 

Some skepticism will help keep us in check and hopefully prevent us from going overboard on climate mitigation, though too much of it may hinder our abilities to use creative and innovative ideas to help deal with the inevitable changes that lie ahead. Balance is key.