Journal ‐ American Water Works Association最新文献

Although it's often claimed otherwise, the beverage industry is not the enemy of the water industry. In fact, bottled water is often the backstop when tap water is not available or acceptable. Common emergencies that can cause a surge in bottled water sales include service outages lasting any longer than a day, incidents that are becoming more common because water systems designed decades ago are facing new stresses from climate extremes. Maybe more common, though, are limited aesthetic events, often seasonal, in which the local tap water just tastes or smells bad.

Bottled water makes a nice Band-Aid, and it can be a lifesaver during emergencies and short-term quality challenges. But continued reliance on bottled water or water kiosks is a budget-killer, and it's often the communities that can least afford it that find themselves paying for packaged water. In fact, bottled water can cost upward of a thousand times more than tap water—but bad-tasting, bad-looking water drives consumers to use more expensive alternatives.

Besides the exorbitant cost compared with tap water, reliance on bottled water has many other downsides. The amount of energy and plastic materials that go into the production and transportation of packaged water is staggering. Plastic bottles are hopefully recycled, but reports are that less than 10% are made from recycled materials. Recently, questions have been raised about how microplastic particles from water bottles can affect human health, and how plastic debris and microplastic particles affect the environment.

Part of the challenge is that bottled water producers have advertising budgets, and in comparison, utilities more often struggle to establish good communication with their communities. Commercial operations can attack the quality of local services, instilling doubt and making you feel richer, sexier, or that you’ve made the better choice if you drink commercial water products.

Manny Teodoro (an author of this month's cover story) and his coauthors explain in The Profits of Distrust (Cambridge University Press 2022) that distrust of tap water doesn’t just reflect a purchasing decision—it's also an indicator of a citizen-consumer's political activity and societal expectations. Consumers who purchase bottled water or use drinking water kiosks tend to have less trust in government, while those who use tap water in their normal day-to-day lives show they have faith that their water is safe and they trust the agencies that produce and regulate it.

Reliability and transparency strengthen an organization's reputation, and it's up to all water professionals to reinforce the reputation of safe, great-tasting tap water—while keeping a case of bottled water in the closet, just in case. Please consider writing an article for Journal AWWA to share your water industry experiences and solutions by contacting me at [email protected].

Having recently published an article in AWWA Water Science, Karl Zimmermann answered questions from the publication's editor-in-chief, Kenneth L. Mercer, about the research.

Design Considerations for Biological Ion Exchange Drinking Water Filters: Resin Selection, Backwash, and Regenerations

Karl Zimmermann, William Szu-Wei Chen, Jaycee Wright, and Madjid Mohseni

I recently completed my PhD with Madjid Mohseni at the University of British Columbia (Vancouver), and I’m now heading into the world of consulting engineering. My PhD focus was to understand biological ion exchange (BIEX), a strategy to operate IEX drinking water filters for the removal of natural organic matter. Typically, IEX filters are regenerated about once weekly with a salt brine to keep them in chloride mode. But at the point when most people regenerate their filters, it's true that they’ve run out of chloride, but what wasn’t understood was that organics removal could continue through ion-exchanging with sulphate. There's also biology going on. Our research looked at describing each of these three mechanisms for organics removal and their relative contributions to overall filter performance.

Karl Zimmermann's research focuses on biological ion exchange filters. Photo by Karl Zimmermann

Karl lives in Vancouver, B.C., with his wife, Bri, and their dog, Ossa. Photo by Karl Zimmermann

During COVID, I helped run a weekly seminar called WESTalks, which grew to be a worldwide event. I met and learned from dozens of water researchers and practitioners around the world, and I learned about the diverse range of water challenges facing society as well as the ways people are addressing these challenges. I became particularly interested in the WASH sector (WAter, Sanitation, Hygiene) and in water projects in developing communities.

Much of the research findings on biological ion exchange water filters come from long-term pilot tests. Here, Karl is taking a sample from a community-scale pilot system. Photo by Karl Zimmermann

In Rajasthan, India, Karl (center, facing away from camera) listens to stories about fluoride-infected waters from local health workers. Photo by Karl Zimmermann

We’re trying to understand more about how BIEX filters can be designed to fit into treatment trains. This article is our group's first attempt to inform the design of BIEX filters, building off our past works describing the underlying science. Now we can confidently move into more industry-relevant work to inform the design and operations of BIEX filters. We’re at a stage to engage further with water practitioners.

Our study was trying to load the BIEX filters totally with natural organic matter. But in the summer months, the river source's dissolved organic carbon would drop way down, which prolonged the time we needed to collect weekly water samples. We also had a huge washout after a November rainst

Every drought begins with a sunny day, and for water utilities facing broader changes in precipitation combined with more weather extremes, these forces magnify the challenges of water management. Beyond tracking regional conditions, utilities must fully understand when their water supplies could be reduced past the point where they can support existing demands. Regardless of the cause of water shortages (natural forces, system component failures, or regulatory actions), utilities around the globe must account for larger variability affecting services that rely on an already-fickle Mother Nature.

As this was written at the start of May 2024, the North American Drought Monitor website showed drought areas were mostly in Mexico, while around the globe conditions ranged from wetter than normal to states of severe drought. These conditions will change, though, and water professionals today must be part meteorologist and part climatologist to understand and communicate issues such as changes in groundwater recharge, lake and reservoir levels, runoff, and snowpack.

In North America, July and August are the season of peak water use. Most utilities are busy with regular operations and warm-weather projects, but if water stress is currently low, it's also a good time to evaluate drought and water shortage response plans to ensure they’re ready for drier times. This is the time to consider operational evaluations of local codes, policies, procedures, and programs; use models to better understand local demand management and supply-side options; and connect with other systems to understand how they are promoting efficient use and managing water resources in their communities.

Risk and uncertainty are increasing as a result of forces beyond local control, so utilities need to enhance their resilience and adaptability to remain sustainable. Staff and local stakeholders must understand locally specific characteristics that may prioritize some responses over others. As decision makers consider a widening range of scenarios, they need to coordinate with other agencies to adopt and implement efficient water use practices and land use policies. As stewards of public health and local resources, water professionals must ultimately understand and address any changes in the quantity, quality, and reliability of local and regional water supplies.

Perhaps most critically, communication between utilities and their customers must be timely and transparent. For guidance, AWWA's 2022 report Designing and Evaluating Effective and Ongoing Drought Communication describes how water systems can customize their drought campaigns on the basis of size, resources, audience, purpose, and message. Continuing forward, utilities must help their customers adapt, even as they respond to the challenges of today and address the threats of tomorrow.

Journal AWWA provides examples and guidance to address these areas; thanks for sharing your experi