American microbiologist wins Lee Kuan Yew Water Prize for work to measure risk of drinking water

SINGAPORE - A microbiologist who transformed the science of measuring risk posed by harmful microbes in water is the recipient of the 2026 Lee Kuan Yew Water Prize.

American scientist Joan Bray Rose, 72, was named the winner on April 16 as a key pioneer of an approach that safeguards the quality of water reuse systems like NEWater, and shaped water management here and beyond.

Her accolade, which honours outstanding contributions to solving global water challenges, was announced by national water agency PUB’s chief executive Ong Tze-Ch’in at a press conference.

“By enabling the mathematical quantification of infection risks, Professor Rose has provided the world a global approach for defining, managing and regulating water safety,” Mr Ong told the media.

“Her work ensures communities worldwide have access to safe drinking water and water for reuse.”

Professor Rose gained prominence from the late 1980s when she led a team to investigate a microscopic parasite, Cryptosporidium, responsible for a spate of waterborne disease outbreaks.

This included a 1993 outbreak in the American Midwestern city of Milwaukee that killed at least 69 people and caused more than 400,000 people to fall ill.

Prof Rose was the first to demonstrate that the parasite was the cause of these outbreaks, and that the transmission of the disease had occurred because of inadequately filtered and disinfected drinking water supplies.

At the time, tests for water safety gave results only after water had been consumed, and also offered limited protection against non-bacterial waterborne contaminants.

To plug this critical gap, Prof Rose and her collaborators pioneered quantitative microbial risk assessment, a method that gauges risk through factors like the concentration of microbes, exposure pathways and potency.

More than four decades after she began her research into the unseen world of disease-causing microbes, Prof Rose is now the Homer Nowlin Chair in Water Research at Michigan State University and director of the university’s Water Alliance. She has also authored more than 300 scientific publications.

In 2016, she was awarded the Stockholm Water Prize, considered by some to be the Nobel Prize of water, and more recently, the International Water Association Global Water Award 2024.

As the 11th recipient of the Lee Kuan Yew Water Prize, Prof Rose will receive an award certificate, a gold medallion and $300,000.

The medallion will be presented to her during the official opening of the Singapore International Water Week 2026 on June 16 by Singapore’s Deputy Prime Minister and Minister for Trade and Industry Gan Kim Yong.

Apart from helping policymakers quantify the tolerable health risk for water sources, Prof Rose’s quantitative microbial risk assessment also strengthens global confidence in relying on recycled water as a viable and sustainable supply of water, the Singapore International Water Week said in a statement.

Singapore has benefited from her expertise over more than two decades as she was instrumental in evaluating the safety of NEWater as part of panels consulted for the Republic’s third tap that turns used water into ultra-clean reclaimed water.

PUB’s former deputy chief executive for operations, Mr Harry Seah, had met Prof Rose during a 1998 study trip to the US that started NEWater. He said she had recognised early on the strategic importance of recycled water to Singapore as a water-stressed nation.

Mr Seah, who was also the project manager of the NEWater study team, described her as a good friend to Singapore who has gone beyond the call of duty to contribute to the Republic’s water story.

Now a PUB senior consultant, he said: “I still remember putting in a request for her to attend a public event in the lead-up to us launching NEWater, and she flew here on short notice just for a few days to lend her support despite her many commitments.”

Prof Rose said Singapore’s water monitoring and wastewater treatment system will prove to be a model for the rest of the world, where awareness about water stress is mounting.

She counts such collaborations that advance science and translate it into policy as the greatest achievement of her career.

In 2015, Prof Rose was named an honorary citizen of Singapore for her contributions to strengthening water quality and safety.

Reflecting on the Lee Kuan Yew Water Prize, she said the award reflects the collective progress in advancing microbial risk science and its role in protecting public health.

“Safe water is one of the world’s most fundamental yet unevenly distributed resources critical to sustaining human life,” she said.

“As microbial risks continue to evolve, strengthening the robustness of our water systems remains an ongoing endeavour to ensure they remain dependable and resilient; safeguarding both water quality and people’s lives.”

This includes the risk posed by mixtures of per- and polyfluoroalkyl substances or PFAS, which stay in the environment for a long time, microplastics and antibiotic-resistant bacteria, she added.

The Singapore International Water Week 2026 is expected to gather 2,500 leaders, experts and practitioners from governments, cities, utilities and industry, and more than 25,000 trade visitors

Previous recipients of the Lee Kuan Yew Water Prize include Dutch microbiologist Gertjan Medema, who pioneered the use of wastewater surveillance to curb the spread of the coronavirus during the Covid-19 pandemic.

Correction note: An earlier version of the story described Milwaukee as a state instead of a city.