Water innovations can quench our thirst – but will people buy into them?

World water supplies face growing pressure from climate change, population growth and rising domestic, industrial and agricultural demand. Innovations create alternative sources of water – but how do we persuade the public that these are safe? David Feldman reports

Countries are turning to water-supply innovations to manage pressures from drought, climate change and growing freshwater demand. The solutions include desalination, wastewater reuse and rainwater harvesting.

Poor sanitation spreads preventable waterborne diseases. According to the United Nations, more than 40 per cent of the world’s population lives in regions where contaminated water kills nearly 1,000 children every day.

A decade ago, a US Intelligence Community Assessment forecast another dire scenario. “During the next ten years, many countries... will experience water problems – shortages, poor water quality... that will risk instability and state failure,” it reported.

Clashes over communities’ shared river water and groundwater basins could lead to war. Droughts could drive mass migrations in the Middle East, sub-Saharan Africa and Central America that lead to conflict.

The World Bank believes that water-supply alternatives work and – with enough support from developed nations – can be affordable. But we need to make these solutions acceptable to people.

Safety first

The story starts with the public. People need to know that water-supply innovations are safe, secure and managed responsibly.Wastewater reuse is a great example. Advanced treatment technologies can clean wastewater to meet safe drinking-water standards.

Reverse osmosis – removing contaminants by filtering water through semi-porous membranes and using ultra-violet light to purify it – is very safe. But will people drink treated wastewater? It takes work to build public confidence and gain trust. People worry about threats to their drinking water from so-called contaminants of concern.

These complex but common chemicals come from older non-stick cookware, waterproof garments, home furnishings and other sources. These pollutants, particularly PFAS, cause cancer and endocrine disruption. They are hard to detect, let alone treat.

No wonder people may feel squeamish about reused wastewater. How do we win them over?

One way to alleviate concern is to use environmental buffers; surface waterbodies or groundwater basins to store water before it enters supply. Using buffers adds time before introducing reclaimed wastewater into drinking water. It blends this water with water from other sources – additional natural treatment – to remove remaining contaminants. It can enhance public confidence that the water is safe.

This indirect potable reuse creates water of higher quality than most drinking water treated in conventional ways, especially when it comes to contaminants such as organic carbon, dissolved solids and toxic chemicals. Australia, Cyprus, Israel, Malta, Spain and parts of southern California successfully treat water in this way.

People worry about end-uses for reused wastewater. Social psychologists say people worry most about bodily contact with recycled wastewater – ingesting, washing with or swimming in it.

But people are far more open to using recycled wastewater where they have no direct contact; for landscape and crop irrigation, firefighting, industrial manufacturing or to restore flow to drought-stricken rivers. People are far more likely to accept this kind of re-use.

The lesson for countries that see wastewater re-use as the way to tackle water shortages is to consider the benefits of indirect uses first.

Israel recycles some 90 per cent of its wastewater, mostly for farming. Singapore also recycles most of its wastewater, selling it to the semi-conductor industry, the country’s major export industry, which needs highly purified water for its processes.

Desalination

Desalination presents its own, different challenges. Around 16,000 desalination plants operate worldwide, supplying water to more than 300 million people. People worry less about desalination than about wastewater re-use.

Most countries meet World Health Organization (WHO) guidelines on desalination. The WHO prescribes environmental monitoring, advises on materials for plant construction that inhibit growth of microbes and recommends procedures to prevent chemicals such as boron and bromides entering drinking water.

Bahrain, Cyprus, Israel, Qatar, the United Arab Emirates and many US states use desalination to make seawater drinkable and take steps to tackle contaminants.

But people worry that desalination threatens marine life and the coastal environment. They worry about safe disposal of brine, noise and plant appearance, the cost of the water and where these plants will be built.

Solutions to environmental worries include fitting near-ocean diffusers to reduce release of brine concentrations into the sea and designing plants to minimise trapping of tiny marine organisms.

Aesthetics, cost, and location are a bigger challenge. Desalination plants consume large amounts of electricity, making water too expensive for customers on low incomes. The cost of desalinated water varies wildly – but it’s generally two or three times more expensive per litre than water from other sources.

Take the average desalination plant in California; an acre/foot of water – about 1.2 million litres, enough to support two families a year – costs about US$2,100. Water from a large rainwater-harvesting project costs US$580 an acre/foot. However, cost differences will narrow as desalination becomes more efficient and as other water sources dwindle.

But there are questions, too, about environmental justice. Recently, conflict emerged over a proposed desalter at Marina and Seaside in California. Many residents said the plant would increase their rates, provide little additional freshwater, threaten sensitive coastal habitats and cut access to the beach.

But last year California’s Coastal Commission, which permits project sites, approved the project, arguing that the plant meets its requirements, both for environmental quality and for water supply.

Israel uses desalination to supply water to many of its towns. It is not always popular. Residents opposed plans to build a plant near Haifa. A former Knesset member called it “an absurd plan that will cause intense harm to [a] rapidly disappearing pastoral area”. The Israel Water Authority is determined to press ahead.

Both examples raise questions about how to address public concerns. They show how much it matters to engage local stakeholders. In both cases, the opponents have lost, leaving a legacy of animosity and ill-will that may jeopardise future projects, drive costly lawsuits, and erode people’s trust in water agencies.

Compromise may be difficult. But these examples highlight how host communities are most open to innovations that match their values and cultural norms. People are more likely to accept new water sources that they believe are legitimate, trustworthy and affordable.

Perceived mismanagement of water in places such as Flint, Michigan has eroded people’s confidence in government. Agencies may feel their proposed innovation benefits people and planet – but they must also understand end users’ concerns.

Let it rain

Communities have harvested rainwater for millennia, even in the arid Dead Sea valley. It does rain sometimes in the world’s driest regions.

We do this worldwide today. Wetlands, urban parks, rain gardens and ponds capture and store rainfall to irrigate fields and gardens and sometimes – after thorough treatment – for drinking water. Storing rainwater tackles local flooding and runoff pollution, too.

Melbourne, Australia and Singapore are among world leaders in rainwater harvesting and illustrate how to make it acceptable to people.

Melbourne aggressively adopted rainwater harvesting after a major drought in 1997-2009. Australia’s second-largest city turned to distributed harvesting and use to make its water supply more resilient and less vulnerable to climate change. People flush their toilets and irrigate parks and landscaping with harvested rainwater.

The state of Victoria has passed laws to use harvested rain more widely, designating stormwater – defined as runoff from streets and parking lots – as city property to use to irrigate public landscape and parks.

The city stores rainwater in large ponds. But householders have the legal right to capture and store rain falling on their own roof or driveway. Rainwater-storage tanks are now a familiar site in Melbourne’s neighborhoods and suburbs. Residents use rainwater to wash clothes and cars and to water their yards.

Singapore has comparatively ample rainfall. The challenge for this city state is how to store and protect rainwater to re-use. Singapore has strengthened its land-use regulations and transformed many catchment areas into recreation sites. These bring Singaporeans closer to water, encouraging citizens to appreciate, value and protect it.

Limiting development in these catchments supports safer, more effective storage in retention ponds and floating wetlands and protects reservoirs from polluting activities. It’s why Singapore is one of the few countries that can harvest urban stormwater on a scale to supply drinking water.

Talk less; listen more

Water innovations can meet communities’ needs, while being economical, safe and resilient. But project advocates need clear, consistent messaging and must work with the public to address people’s concerns. One project that did this well is the Groundwater Replenishment System in Orange County, California.

This wastewater-reuse enterprise recycles sewage to replenish groundwater. From the outset, in 2008, project manager Orange County Water and Sanitation Districts consulted local people and solicited local providers’ water needs.

A multi-pronged outreach campaign canvassed public opinion, holding community meetings and creating a citizens’ advisory committee to address concerns about the risks. The campaign explained what made the project more effective than other options, creating a reliable, secure and drought-proof water supply.

Critically, the local water district worked with under-represented groups – including recent immigrants worried about water purity and reliability – and sought endorsements from public-health officials. Today, the system supplies 100 million gallons of high-quality water daily, supporting some 850,000 residents – nearly a third of the county’s population.

In a follow-up study, the water district found that it had been critical to identify “the issues key stakeholder groups may have with a proposed project... developing talking points and collateral materials that can answer any questions”.

Concern about drinking-water safety is non-negotiable. We have to trust those who provide it. Most people worry about water sourced using complex technologies whose workings they only dimly understand.

And these are not idle concerns. People remember what happened in Flint, Michigan, where it emerged in 2015 that lead in the distribution pipes was contaminating the drinking water. This threatened public health. But worse, the public authorities denied there was a problem, claiming to have taken steps to prevent lead leaching into the water supply.

Investigations proved they had not – that Flint had a long-term problem with underinvestment in water treatment. Flint is a Black-majority community. Campaigners called out racism and neglect.

Jackson, Mississippi has faced similar problems – it’s another minority community suffering chronic poverty, a low tax base and years of water-infrastructure neglect. The city’s problems with drinking water supply date back more than a decade. Last summer, heavy flooding forced the authorities to provide emergency bottled water.

Little wonder people lose trust. We must address their concerns. Our ability to meet our future water needs depends on it.

David Lewis Feldman is professor of urban planning and public policy and political science and director of Water UCI in the School of Social Ecology, University of California, Irvine: feldmand@uci.edu