Featured Video: Why Are 96,000,000 Black Balls on This Reservoir?

By Jill Wallitschek

In 2015 the Los Angeles Department of Water and Power went viral when it unleashed 96 million shade balls into the Los Angeles Reservoir. The 175 acre reservoir served to store 3.3 billion gallons of treated drinking water. Shade balls were previously introduced to three other reservoirs in the LA area between 2008 and 2012. Releasing the 96 million balls marked the end of a 8 year project.

The project was first instigated when the Department of Water and Power was notified of high bromate levels in their water. Bromate (BrO₃^- ) is a disinfection byproduct regulated at 0.01 mg/L. High levels can increase risk of cancer. The chemical forms when bromide (Br ^- ), an otherwise harmless ion, reacts with ozone (O₃). For this reason treatment plants that use ozone are required to monitor for bromate monthly. Qualifying plants can reduce their monitoring to quarterly.

The LA Department of Water and Power determined that while they were finding low levels at the treatment facility, levels were elevated at the reservoirs. Upon investigation the facility realized that bromate can form under chlorination as well. When chlorinated water containing bromide reacts with sunlight, it forms bromate at even higher concentrations than ozonation. This realization prompted the facility to look toward a solution.

Removing the naturally occurring bromide wasn’t an option. Chlorination residual was necessary to protect public health. Ultimately the Department determined that sunlight was the only variable left to control.

After brainstorming for affordable and effective covers that could block sunlight across 175 acres, the Department discovered a product called “bird balls”. At the time, bird balls were used to deter waterfowl from swimming in contaminated water bodies or ponds near airport runways. These balls were made from high density polyethylene, a floatable, food grade plastic. The addition of carbon black gives them a black color and increases their life expectancy to approximately 10 years without sun bleaching. After consulting the manufacture, the balls were put through a small-scale test to access their bromate reduction abilites. The shade balls passed with flying colors.

Shade balls not only reduce bromate formation in the reservoir, but they deter birds, control algae, and reduce evaporation by 80 to 90%. Having been implemented under historical drought conditions, the innovation was applauded for its water saving results. According to the Massachusetts Institute of Technology these shade balls will have to be used for roughly 2.5 years to compensate for the water required to produce them. Since less chlorine is required to control algae formation with the adoption of shade balls, the treatment facility is experiencing significant cost savings as well. Over the course of their life span the reduction in chlorine use and evaporation will have paid for roughly half the shade balls.

Shortly after their installation, one of the reservoirs was removed from service and two of the remaining reservoirs transitioned to floating covers. Federal law requires that all drinking water bodies open to the air be covered. Transitioning the final Los Angeles Reservoir would have been too cost prohibitive based on its size. So given the effectiveness of the shade balls in such a large area, they shall remain in the Los Angeles Reservoir to prevent bromate formation, evaporation, and algae for the Los Angeles people.

Featured Video: Infusing Innovation into the DNA of Our Culture

There are many factors that drive the current utility model for wastewater operations. With traditional values in play, we have reached difficult economic and operational challenges. In order to address these challenges, we must adapt a new mindset and new utility model to push affordability for water customers, better equipment management, and increased compliancy.

Adapting a more innovative approach and mindset:
Our current utility practices suggest that our societal and business values coincide with "extraction, use, and waste disposal". This creates a motivation that is, at bare minimum, driven by public engagement, capital investment, and operations & maintenance. As a result our current water resources are being utilized inefficiently and ultimately running low. We must instead adapt a Resource Recovery business model for a circular economy. Focus must be shifted from regulatory compliance, utility impact, and traditional utility models to pivot toward ecological uplift, collective impact, and a transformative entrepreneurial business model. This new business model should include focus on resource recovery and watershed health as well as pump, plant, and pipe health.

The start of a new, innovative, and effective approach might be slow but can grow exponentially. Water organizations must start with efficiency and work their way to optimization, which will lead into investments for bigger ideas and new intellectual property such as smart meters, efficient pumps, proper monitoring equipment, better facilities, and so forth. Collective cooperation and corresponding mindsets will keep the industry on the same track with the addition of new water personnel and management turnover.

In this week’s featured video by the Water Research Foundation, Diane Taniguchi-Dennis, Deputy General Manager at Clean Water Services, presents a case study for how her organization is improving utility functionality through a culture of innovation.

Featured Video: Sewer Cleaning in Los Angeles California with Kent Carlson

For roughly 30 years Kent Carlson worked for the City of Los Angeles to bring innovation and new technology to the Department of Public Works’ Bureau of Sanitation. When the Bureau observed that new technology was falling behind on their collections side, Kent was brought over to assist with tool development and the standardization of sewer cleaning procedures. Under the mission to reduce sewer overflows and recognize increasing drought in southern California, one of his favorite inventions featured a sewer nozzle designed to reduce water use and save time during cleaning.

In his article with CWEA Water News he offers his predictions on the future of the sewer profession asserting, “I think it’s an exciting future – technology is exploding in this sector – CCTV, GIS, computers on the trucks. Sewer workers of the future will be much better with technology. Rather than using rudimentary brute force for cleaning we’ll get smarter, more strategic and more efficient at what we do.”

Kent’s enthusiasm for tool development is demonstrated in this week’s featured video. The 5-minute video highlights the history of sewer cleaning in Los Angeles as well as a demonstration of how his team tests and develops their sewer cleaning tools. Back in the day, sewer cleaning featured manual removal of clogged pipes and sewer mains. Today, his team takes advantage of high-pressure tools and robotics. Kent says the best tools for sewer cleaning are designed or personally modified by the facility staff. These tools ultimately help the Bureau of Sanitation affordably maintain approximately 6,500 miles of pipe, some of which was originally installed as far back as 1883. We hope this week's featured video inspires your system to find new and innovative ways to help your utility operate more efficiently.