Clean energy and sustainability experts share water conservation tips, debunk common myths, and explain why water is so important in the fight against climate change.
On Sunday, March 22, communities across the globe will come together for World Water Day, an annual UN observance that highlights the importance of freshwater and the sustainable management of freshwater resources. In keeping with the tradition of past years, UN-Water has selected a theme for the 2020 celebration: Water and Climate Change.
To further this conversation and learn more about the importance of our clean water supply, we sat down with two BU experts: Dr. Jacqueline Ashmore, executive director of BU’s Institute for Sustainable Energy (ISE) and a research associate professor in the Department of Mechanical Engineering and Dr. Cutler Cleveland, associate director of the ISE and Professor of Earth and Environment. Dr. Ashmore is a clean energy and sustainability expert with fifteen years of experience in technology, business, and policy. Her research now focuses on integrated water management and approaches that support sustainable and affordable water supplies. Dr. Cleveland shares many of the same research interests, with a specific concentration on climate change.
Why is it important for people to be aware of how much water they use on a day to day basis?
Ashmore: We don’t think about this often here these days, but clean water is absolutely a finite resource. It takes a lot of resources and infrastructure to convert sourcewater to a reliably drinkable state; the price of water from the faucet does not reflect the full cost of sourcing, treatment, and distribution because it is vital to life and we don’t want to restrict access. Yet there is a concerning trend: the need to replace water infrastructure and the effect of climate change on water sources is driving a notable year-over-year increase in costs — and therefore in prices too. As someone who is deeply concerned about the urgency of addressing climate change, I also believe that it is too easy to overlook the challenges we may encounter quite soon around water availability, even potentially in places where water appears plentiful right now.
Cleveland: Monitoring water use produces a number of economic, environmental, and social benefits. Less water use translates directly to lower water utility bills. In arid regions, water conservation reduces the likelihood of water shortages and water rationing. In regions that rely on groundwater, water conservation reduces the chances of underground aquifer depletion.
In recognition of World Water Day, what are some small ways that individuals can conserve water and reduce their water consumption?
Cleveland: Use a reusable water container to decrease the amount of cups that need to be washed/recycled/disposed of. Wash only full loads of laundry and/or or combine with a roommate or friend. Only run the dishwasher when there is a full load, use the shortest cycle, and do not select the heated drying option. Additionally, shifting to a plant-based diet will reduce water use because meat and dairy products are far more water intensive compared to plants.
Ashmore: Use water efficient toilets and shower heads. Wash full loads of laundry rather than a small number of items, and only run the dishwasher when it is full. Another point to consider is whether you irrigate and, if so, whether you do so in a targeted way only during extended periods of dry weather, and only early or late in the day when evaporation is minimal.
Do you think the ways in which people are mindful of their carbon footprint should translate to concern for their “water footprint” as well?
Cleveland: This works in both directions. The largest source of anthropogenic greenhouse gas emissions are from the use of fossil fuels. Producing coal, oil, and natural gas requires a lot of water at every stage of the supply chain. Using less energy, improving the efficiency of energy end use, and shifting to renewable energy sources such as wind and solar will reduce the water requirements of energy production and use. The flip side is that the supply of water requires a lot of energy to pump, purify, and deliver clean water. Reducing our water footprint thus decreases our climate footprint.
Ashmore: It is really helpful for people to be conscious of how much water is used to support different activities, and to make choices accordingly. As with our carbon footprint, some ways in which we use water are not immediately visible to us. In the US, agriculture accounts for about 80 percent of water use. Different foods vary considerably in how much water is involved in their production: a quarter pound of beef requires 461 gallons of water; an apple needs 33 gallons of water.
What happens when people use too much water; what is the larger impact on the Earth?
Ashmore: Ultimately our water is drawn from rivers, reservoirs, or underground aquifers. If human demand exceeds the natural replenishment rate of local sources, then the imbalance will ultimately lead to some form of breakdown. Cape Town came very close to “Day Zero” when faucets were projected to run dry in March 2018, largely as a result of climate change reducing the replenishment rate of water.
Cleveland: The overuse of water can deplete underground aquifers and in doing so raise the cost of pumping water from greater depth. Overuse of water from both underground and surface sources can cause utility bills to increase. Overuse of water can lead to water shortages, especially in arid regions, that can raise prices and cause water rationing. Overuse of water will make it harder to respond to changes in water precipitation and runoff caused by climate change.
With an ever-growing population, how is the world’s water supply affected?
Ashmore: I’ll start with some good news: in much of the developing world increased water efficiency is leading to reduced per capita usage of water. However, overall the increase in the world’s population and also the increase in people seeking meat-based rather than grain-based diets drive increased demand for water. (Note in the question above we discussed the difference in water intensity of beef compared to an apple.) Aside from total demand, the geographical concentration of water demand in growing cities is an additional challenge. We need thoughtful professionals to enter the water management industry to help address these challenges.
Cleveland: According to the World Health Organization (WHO), between 50 and 100 liters of water per person per day are needed to ensure that most basic needs are met and few health concerns arise. By definition, more people means more water use. But other factors affect how much water each of us uses. The higher your standard of living, the more water you use, especially water embodied in the goods and services that you purchase. Inefficient technologies in the water supply system, our kitchens and bathrooms, and in our businesses, farms, and factories lead to the inefficient use of water. Water policies that include property rights access, and pricing all affect how much and how efficiently water is used. It’s not just about population growth.
How can we work to best identify how widespread water pollution is, and are there any solutions to protect ourselves and future generations?
Ashmore: We really need to be mindful of the myriad ways in which water becomes polluted and how that propagates through our entire water cycle. Pharmaceuticals that we wash away persist; microplastics in the relatively clean waste water from baths, sinks, washing machines, and other kitchen appliances persist; PFAS are chemicals that originate from Teflon and other compounds that also persist. We need to consider: what happens to wastewater and industrial effluent? Where and when are combined sewer overflows occurring? What substances reach water bodies after being deposited on streets and then being carried to water sources via stormwater runoff? What leaches from agricultural areas into our groundwater?
Cleveland: Households have a critical role in reducing water pollution. Here are three behavioral changes to reduce pollution: First, do not flush pills, medications, or drugs down the toilet. Second, do not use the toilet as a wastebasket. Most tissues, wrappers, and other paper and plastic goods that cannot be recycled should be discarded in the solid waste stream. Third, minimize or eliminate your use of pesticides, herbicides, and fertilizers. Do not dispose of these chemicals, motor oil, or other automotive fluids in the sanitary sewer or storm sewer system, where they would end up in river, lake, and marine ecosystems.
Are there any myths about water conservation?
Cleveland: Where to begin? Here are two common myths about water.
MYTH: The Earth’s surface is 71 percent water — why worry?
FACT: Fresh surface water sources such as rivers and lakes — the sources of most of the water people use everyday — constitute just 1/150th of one percent of all water on Earth. That small fraction is diminished plagued by overuse, waste, leakage, and pollution.
MYTH: Bottled water is safer than tap water.
FACT: Both tap and bottled water are treated to improve quality, but tap water is tested more frequently than bottled water and is subject to more stringent testing in some states. About 25 percent or more of bottled water is really just tap water in a bottle. It takes 1.63 liters of water to make every liter of Dasani, and millions of tons of plastic bottles are clogging landfills and harming marine life.
For additional commentary by Boston University experts, follow us on Twitter at @BUexperts. For more research and updates from BU’s Institute for Sustainable Energy, follow @ISE_BU. Follow Dr. Cleveland @cutlercleveland and Dr. Ashmore @JacquieAshmore.