September 21, 2016

The state of North Carolina could prevent an estimated 2,920 annual emergency department visits by extending community water service to 10 percent of the population that currently relies on private wells. This finding comes from a recent study co-authored by three researchers linked with the UNC Gillings School of Global Public Health.

Dr. Jackie MacDonald Gibson

Dr. Jacqueline MacDonald Gibson

Jacqueline MacDonald Gibson, PhD, associate professor of environmental sciences and engineering, is senior author of the paper. Her co-authors, both alumni of the Gillings School’s environmental sciences and engineering department, are Nicholas DeFelice, PhD, postdoctoral research scientist in the Department of Environmental Health Sciences at Columbia University’s Mailman School of Public Health, and Jill Johnston, PhD, assistant professor in the Division of Environmental Health at the University of Southern California.

The full article, titled “Reducing Emergency Department Visits for Acute Gastrointestinal Illnesses in North Carolina (USA) by Extending Community Water Service,” was published online by the journal Environmental Health Perspectives.

Approximately 35 percent of the N.C. population currently relies on private wells for their drinking water. Previous studies of water quality suggest that private wells carry a higher risk of exposure to microbial contamination compared with regulated community water systems, but the health impact associated with these unregulated drinking water sources was unknown.

To better frame the issue, the researchers estimated the total number of emergency department visits across N.C. each year related to severe gastrointestinal illness that was attributable to microbial contamination in private wells. They also analyzed the costs of those visits and the potential public health benefits of extending regulated water service to households that currently rely on private wells for drinking water.

The investigators used 2007-2013 data from all 122 N.C. emergency departments, along with microbial contamination data for all 2,120 community water systems and for 16,138 private well water samples.

The results showed that an estimated 29,400 emergency department visits per year for acute gastrointestinal illness were attributable to microbial contamination in drinking water. Of these cases, 99 percent were associated with private wells. The estimated statewide annual cost of the visits arising from private well contamination was $39.9 million.

Extending community water service to 10 percent of the population that now relies on private wells would prevent an estimated 2,920 emergency department visits annually, the study found. This research provides new evidence that extending regulated community water service could decrease the population burden of acute gastrointestinal illness.

“While most households relying on private wells for their drinking water are in rural areas, some live in urbanized areas on the fringes of cities and towns and could be connected to nearby municipal water lines, hence decreasing their risk of gastrointestinal illness,” said MacDonald Gibson. “Our research also has shown that in some counties, African-American neighborhoods in urbanized areas are particularly at risk of lacking a connection to a municipal water system that could provide a better quality of water than the households currently receive from their wells.”

MacDonald Gibson’s future research will assess the costs and feasibility of connecting municipal water lines in some of these urbanized areas.


Gillings School of Global Public Health contact: David Pesci, director of communications, (919) 962-2600 or



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