If you are like the majority of Americans, you don’t think much of the water you use to drink, bathe, and do other basic necessities. For the approximately two billion people who live in places where water sources are contaminated with feces, it can be a matter of life and death: contaminated drinking water is estimated to cause 485,000 diarrheal deaths each year, most of them children, according to the World Health Organization.
Jenna Davis, director of Stanford’s Program on Water, Health and Development is one of several Stanford water experts in New York City this week for the United Nations 2023 Water Conference – the first major UN water summit in nearly 50 years. The conference is expected to result in commitments from governments, civil society and private sector groups on ways to "accelerate our progress towards water-related goals and targets." On March 22, World Water Day, Davis discussed surprising freshwater challenges and potential solutions in the U.S. and abroad. (Read about and watch livestreams of conference panels and meetings featuring Stanford researchers.)
Although most Americans have great water and sanitation services, recent failures such as lead contamination of water supplies in Flint, Michigan, remind us that not all communities have that luxury. People might also be surprised to know that contaminants like lead are regulated one at a time. For example, having a low concentration of copper in my water supply is not known to be a health risk. But we don’t know much about my health risk if my water also contains below-threshold levels of nitrates, cyanide, and chromium. Bill Mitch, a professor of civil and environmental engineering at Stanford, has been looking at this issue for chemical contaminants that are created during water treatment processes. Only a handful of these are regulated so far. Bill’s work is showing that many unregulated chemicals may have larger health risks than the ones we regulate (listen to a podcast episode about Mitch’s work, “recycled water purity and fears of a fungal future” ). Going forward it will also be important to consider how regulatory approaches can better reflect the cumulative risk associated with having many low-level contaminant exposures at the same time.
I think many people don’t realize that the lowest income households often pay some of the highest prices for water supply per unit volume. The reason why is the same reason that the price for a bottle of water in the U.S. is 1,000 times higher than the same amount of water from a piped connection. Folks who don't have access to piped water supply have to fetch it or have it delivered one container at a time, also with unit prices that are much higher than piped water. So it’s not that these household can’t afford the day-to-day costs of higher service. The challenge is that it takes a big up-front investment to transition from this lower level of service to a piped system where you can start to benefit from economies of scale. We still have about a billion people to go in that regard.
I think most people in the U.S. would be surprised to learn how much energy you can get out of wastewater. Some European countries are far ahead of us on this. Stanford researchers like Meagan Mauter, Craig Criddle and Dick Luthy, professors in civil and environmental engineering, are working to advance these kinds of technologies and demonstrate their potential to scale. In addition to generating energy and recovering water and other valuable resources that we can use, wastewater recycling is essential for transitioning toward more decentralized and modular water supply infrastructure. That kind of flexible design will be critical as a climate change adaptation strategy.
I think it’s pretty clear that the definition of good water engineering is no longer about long-lived assets and highly centralized systems. We also don’t have the luxury of continuing to manage water supply as if it were independent of our wastewater. At the same time, some of the radically decentralized solutions that have been developed—particularly with regard to water quality management in low- and middle-income countries—have both practical and normative challenges. If we’re going to ask every household to manage their own water quality we need technologies that require a lot less time and effort than the ones we’ve tried so far. I also think we need to ask ourselves if we are OK with asking lower-income households to shoulder this responsibility while wealthier households just rely on a service provider or utility to make their water safe.
A lot of the obstacles have nothing to do with technology and very little to do with money or knowledge. They have to do with professional incentives, institutional inertia, and constraints that make it hard for us as a society to take more risks. In the freshwater field this risk aversion means we have many promising technical, financial, and policy innovations that haven’t been tested at a meaningful scale. But timing is everything—opportunities to make meaningful change can arise at any time, such as in the form of a crisis or a change of leadership. If you keep working to refine your solution and get clear about the conditions under which it’s likely to work, you’ll be ready when that window of opportunity opens.
Engineers are trained to see our job pretty narrowly, but if we think something is a solution we need to look at it from all sides. We can’t just ask if it works technically. We also need to ask who's going to use it? Why would they prefer it to what they've got now? Who's going to pay for it? Who's going to maintain it? We can’t just assume that somebody else will figure all that out. Let’s ask the questions and start the conversations about those other issues, even if we're ultimately not going to be responsible for tackling them. Even better, we should be including those questions as part of the design process from the start. I think we’ve embraced that ‘360-degree approach’ with our Lotus Water project, which envisions a new water treatment paradigm centered on passive chlorination of water supplies. We’re not just trying to solve poor microbiological quality of drinking water from an engineering perspective—there are already plenty of technologies that can do that effectively. But often they only work in a lab, or they work in very short field trials when researchers come by to check on households and be sure they’re using them correctly. That’s not ‘real world.’ A truly sustainable solution has to work over the long term, day in and day out, in both the rainy and the dry season, without needing repeated ‘injections’ of support from external actors. For us that means having a technology that doesn’t require electricity and has no moving parts. For the business model that means delivering a service that households want at a price they’re willing and able to pay, while also allowing their service provider to make a decent living. If any one of those facets doesn’t work, can we really claim to have a solution?
I’m surprised at how little collaboration is occurring between people who think of themselves as freshwater specialists and people who think of themselves as climate specialists. The way that most people in the world experience climate change is through water—having too little or too much, getting it at the wrong time, or dealing with declining water quality. These experiences should be informing policy and program development for climate change adaptation. We should also see them as an opportunity to stimulate learning and civic engagement around climate change. In my own family, three months of unprecedented flooding has done more to shift some relatives’ climate change beliefs than years of my lecturing at them ever did!