Low-flow water systems in buildings are designed to conserve water, but they pose potential health hazards because they may cause an increase in disease-causing organisms and harmful chemicals.

A new Environmental Protection Agency-funded project led by Andrew Whelton, assistant professor of civil engineering, aims to help solve the problem.

“The increasing occurrence of low flows in water distribution systems and building plumbing presents an emerging health concern. Opportunistic pathogens more easily multiply under low-flow conditions,” Whelton says. “Building designers, managers, and health officials need better information and models to predict health risks in plumbing systems found in all sorts of buildings, from schools, to homes, to healthcare facilities.”

The organisms include the bacterium Legionella pneumophila, which causes Legionnaires disease; the brain-eating amoeba Naegleria fowleri; Pseudomonas aeruginosa, an antibiotic-resistant pathogen associated with serious illnesses; and Mycobacterium avium, which causes respiratory illness, especially in immunocompromised people.

“These opportunistic pathogens continue to cause waterborne disease outbreaks across the country,” Whelton says. “In fact, Legionella remains the most identifiable cause of waterborne disease in the U.S.”

Purdue will work with researchers at Michigan State University (MSU) and San Jose State University (SJSU) to better understand and predict water quality and health risks posed by declining water usage due to water conservation fixtures, reduced water usage and low flows. The group is funded with a $2 million grant from the EPA. The three-year project, which began in January 2017, also will be funded with $1.1 million from non-federal sources, including Whirlpool Corp., Citizens Energy Group and the Avon Community School Corporation.

“The research announced today will guide decision makers as they design, renovate or manage plumbing systems to provide safe and clean drinking water,” says Thomas Burke, agency science adviser and deputy assistant administrator of EPA’s Office of Research and Development.

The grant application from the Purdue-SJSUMSU team included numerous letters from people who have benefited from the advice of researchers. Letters of participation and support were submitted by the American Society of Plumbing Engineers, the United States Green Building Council, Indiana Rural Water Association, water utilities, architectural and engineering firms, and researchers from Canada, Denmark, Israel and the United States. Support also was expressed by the American Water Works Association, Healthy Building Network, National Institute of Standards and Technology, and the National Environmental Health Association.

“We designed our project based on drinking water safety concerns from the public, industry and government agencies. Our approach harnesses world-class expertise from industry and other academics,” Whelton says. “We have an amazing team and are eager to start working more closely with our project collaborators and supporters.”