Nav: Home

Water conservation can have unintended consequences

September 13, 2017

Conventional wisdom dictates water conservation can only benefit communities affected by drought. But researchers at the University of California, Riverside have deduced that indoor residential conservation can have unintended consequences in places where systems of wastewater reuse have already been implemented, diminishing both the quantity and quality of influent available for treatment.

The researchers outlined their findings in a recent paper, which appears online in the journal Water Research, published by the International Water Association.

"Drought, and the conservation strategies that are often enacted in response to it, both likely limit the role reuse may play in improving local water supply reliability," wrote Quynh K. Tran, a UCR Ph.D. student in chemical and environmental engineering; David Jassby, associate professor of chemical and environmental engineering; and Kurt Schwabe, professor of environmental economics and policy.

In the past, recycled water was only applied to areas such as low-value crops and median strips, Schwabe said. Recently, however, it has been considered safe to drink provided it either undergoes multiple rounds of treatment to remove concentrations of salts, nutrients, and other contaminants, or is injected into the ground and pumped back out later.

The United States reuses between 10 percent and 15 percent of its wastewater. In regions like Southern California, where effluent flows from inland communities down the Santa Ana River Basin and toward the coast, indoor residential conservation can limit downstream water supplies.

"You often hear it never stops raining at a wastewater treatment plant, meaning the influent from households will continue to flow regardless of whether we're in a drought or not," Schwabe said. "It may be true that it will continue to 'rain,' but the quantity of flow can be severely impacted by drought and indoor conservation efforts, which has implications for the reliability of the system, especially when it comes to downstream or end users of the treated wastewater."

Schwabe added the problem is pervasive in linked systems of wastewater reuse.

"If people are taking fewer showers and flushing their toilets less frequently, simple water balance dictates there can be reliability issues surrounding the reuse of water in systems such as those we have in Southern California," he said.

Exacerbating the problem, as wastewater flows decrease, their levels of salinity and other pollutants increase. Higher levels of pollutants present significant challenges for treatment facilities that are not typically designed to handle "elevated concentrations of total dissolved solids, nitrogen species, and carbon," according to Tran, Jassby, and Schwabe.

However, the researchers said solutions to those problems are available.

"Cost-effective blending strategies can be implemented to mitigate the water quality effects, increasing the value of the remaining effluent for reuse, whether it be for surface water augmentation; groundwater replenishment; or irrigation of crops, golf courses, or landscapes," they wrote.

To develop an economic model by which wastewater can be treated in a more cost-effective way, thereby increasing its value, the researchers identified feasible wastewater treatment technologies and wastewater treatment trains either in use or available for potential use. A treatment train is a sequence of treatments aimed at meeting a specific standard.

"Our solution is based on a system of blending water," Schwabe said. "Traditionally, wastewater facilities have operated by the principle that all the influent is treated to the fullest extent possible. But depending on the sort of demand and regulations a treatment plant confronts for its effluent, managers may have the opportunity to be creative and achieve a much less costly outcome by treating only a portion of the influent with the most advanced technology and blending this with the remaining influent that has been treated but with a less advanced and thus lower-cost process."

Schwabe said while this research indicates indoor water conservation may affect the reliability and quality of water reuse during drought, the researchers are not suggesting people engage in less frequent conservation.

"These results highlight a central tenet of economics: that there's a cost with every action we take," he said. "Our results are intended to illustrate how different drought mitigation actions are related so agencies can plan, communicate, and coordinate in the most informed and cost-effective manner possible."
The research was funded by the United States Department of Agriculture and the Binational Agricultural and Research Development Fund, a U.S.-Israeli partnership.

The University of California, Riverside is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment has exceeded 20,500 students. The campus will open a medical school in 2013 and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.

University of California - Riverside

Related Drought Articles:

Vinegar: A cheap and simple way to help plants fight drought
Researchers at the RIKEN Center for Sustainable Resource Science (CSRS) have discovered a new, yet simple, way to increase drought tolerance in a wide range of plants.
Lending plants a hand to survive drought
A research team led by the Australian National University has found a new way to help plants better survive drought by enhancing their natural ability to preserve water.
New rice fights off drought
Scientists at the RIKEN Center for Sustainable Resource Science (CSRS) have developed strains of rice that are resistant to drought in real-world situations.
Drought linked with human health risks in US analysis
A Yale-led analysis of health claims in 22 US states found that severe drought conditions increased the risk of mortality -- and, in some cases, cardiovascular disease -- among adults 65 or over.
A basis for the application of drought indices in China
The definition of a drought index is the foundation of drought research.
Under the Dead Sea, warnings of dire drought
Nearly 1,000 feet below the bed of the Dead Sea, scientists have found evidence that during past warm periods, the Mideast has suffered drought on scales never recorded by humans -- a possible warning for current times.
Forests worldwide threatened by drought
Forests around the world are at risk of death due to widespread drought, University of Stirling researchers have found.
How much drought can a forest take?
Why do some trees die in a drought and others don't?
Pressures from grazers hastens ecosystem collapse from drought
Ecosystem collapse from extreme drought can be significantly hastened by pressures placed on drought-weakened vegetation by grazers and fungal pathogens, a new Duke-led study finds.
Molecular conductors help plants respond to drought
Salk scientists find key players in complex plant response to stress, offering clues to coping with drier conditions.

Related Drought Reading:

Droughts (Blastoff! Readers: Extreme Weather) (Blastoff! Readers, Level 4: Extreme Weather)
by Anne Wendorff (Author)

The Midwestern United States was nicknamed The Dust Bowl in the 1930s because years of drought devastated the region. This book teaches why droughts happen, how they affect living things, and the importance of conserving water. View Details

Droughts (Pogo: Disaster Zone)
by Cari Meister (Author)

In Droughts, early fluent readers learn about the conditions that lead to and result from catastrophic water shortage. Vibrant, full-color photos and carefully leveled text will engage young readers as they learn about the deadliest droughts and how to help prevent them. An infographic illustrates areas of the world at risk for drought, and an activity offers kids an opportunity to extend discovery. Children can learn more about droughts using our safe search engine that provides relevant, age-appropriate websites. Droughts also features reading tips for teachers and parents, a table of... View Details

Droughts (Let's-Read-and-Find-Out Science 2)
by Melissa Stewart (Author), Andre Ceolin (Illustrator)

The earth—and everything on it—needs water. But lately, it’s been unusually sunny, warm, and dry. The weather anchor announces that your area is experiencing a drought! Where do droughts happen? How do we know that we are in a drought? Why is rainfall important? Do droughts just affect people? Can scientists keep track of rainfall? Read and find out!

This book is full of activities, like how to measure rainfall, how to visualize how much of the world’s water is freshwater, and how to create a cloud in a jar. It’s also full of graphic features perfect for visual learners,... View Details

The Drought: A Novel
by J. G. Ballard (Author)

An apocalyptic dystopia like no other, one whose "originality and power [of] vision can be felt" (Times Literary Supplement).

Weird and mesmerizingly grotesque, The Drought tells the chilling story of the world on the brink of extinction, where a global drought, brought on by industrial waste, has left mankind in a life-or-death search for water. Violence erupts and insanity reigns as the human race struggles for survival in a worldwide desert of despair. View Details

The Drought-Defying California Garden: 230 Native Plants for a Lush, Low-Water Landscape
by Greg Rubin (Author), Lucy Warren (Author)

A must-have for every gardener in California looking for a new way to garden in a changing climate

In recent years California has been facing extreme drought, and in 2015 they passed state-wide water restrictions that affect home owners. Unfortunately the drought is only going to get worse, and gardeners who aren’t willing to abandon their beloved pastime entirely are going to have to learn how to garden with the absolute minimum of water. The Drought-Defying California Garden highlights the best 230 plants to grow, shares advice on how to get them established,... View Details

Drought Season Over: The Sequel
by Keith L. Bell (Author)

Ready to find out what happened to Kilo and Kenya? Slim and Ivonne? Fresh and all his pieces? Cant forget about Quick. Ready to find out how they escaped the cartel? Or if they escaped? Get ready because its about to go down in the streets of Youngstown, Ohio, once again. View Details

Drought (Natural Disasters)
by Terry Jennings (Author)

The wind, rain and sea are powerful forces with the potential to cause devastation. Natural Disasters introduces children to nature at its most powerful, showing not only the damage that can be done to people and property but also ways in which we are able to forecast weather to minimise damage. Each book begins with an introduction describing the forces of nature, how they begin and what makes them grow stronger. The books then go on to show how and where disasters occur, other weather phenomena associated with the same natural forces, and how we track and respond to them. Each book contains... View Details

Drought-Adapted Vine
by Donald Revell (Author)

"Donald Revell writes with a drunken equipoise among the weedy flowers and bees of roadside museums and vacant churches. . . .[Here] are poems that border the hereafter and revive the child's play of prophecy. What miraculous assistance they provide!"—Dean Young

Donald Revell pushes boundaries between words and music, transcending our current notion of beauty and innocence. Personal memory, the visionary, the eccentric, and the divine intertwine between networks of stories that connect past and present through paint strokes, composition, and pastoral lyric. Pure of heart poems lie... View Details

Droughts: Be Aware and Prepare (Weather Aware)
by Martha E. H. Rustad (Author)

It hasn’t rained in weeks. Crops are wilting, and the grass is dry. Rivers run low. Is it a drought? How do you know? And how can you prepare for what’s to come? Droughts: Be Aware and Prepare has the answers. View Details

Waterwise Plants for Sustainable Gardens: 200 Drought-Tolerant Choices for all Climates
by Scott Ogden (Author), Lauren Springer Ogden (Author)

“I can't imagine a designer or avid gardener who wouldn't want this on their bookshelf.” —Garden Design Online

Waterwise Plants for Sustainable Gardens is a practical guide to the best 200 plants guaranteed to thrive in low-water gardens. Plant entries provide the common and botanical name, the regions where the plant is best adapted, growth and care information, and notes on pests and disease. This practical and inspiring guide includes a variety of plants, from trees to succulents, perennials to bulbs, all selected for their wide adaptability and... View Details

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

The Consequences Of Racism
What does it mean to be judged before you walk through the door? What are the consequences? This week, TED speakers delve into the ways racism impacts our lives, from education, to health, to safety. Guests include poet and writer Clint Smith, writer and activist Miriam Zoila Pérez, educator Dena Simmons, and former prosecutor Adam Foss.
Now Playing: Science for the People

#465 How The Nose Knows
We've all got a nose but how does it work? Why do we like some smells and not others, and why can we all agree that some smells are good and some smells are bad, while others are dependant on personal or cultural preferences? We speak with Asifa Majid, Professor of Language, Communication and Cultural Cognition at Radboud University, about the intersection of culture, language, and smell. And we level up on our olfactory neuroscience with University of Pennsylvania Professor Jay Gottfried.