It may not have been bad shrimp or dirty lettuce that kept you up all night. A recent study shows that in North Carolina, microbes in drinking water from private wells are responsible for estimated 29,200 emergency room visits for acute GI illnesses each year. That number accounts for nearly all visits of that type and cause.
This is a particularly serious problem in North Carolina, where more than a third of all residents — 3.3 million — rely on private wells for their drinking water. These wells, which can source their water from beneath the ground, a spring or a river, are largely unregulated.
(This is why contaminants from coal ash, such as arsenic, lead and chromium 6, which have even more harmful long-term health effects, are of such concern — and why widespread testing is necessary.)
An article in this month’s Environmental Health Perspectives — among its co-authors is Jacqueline MacDonald Gibson of UNC’s Gillings School of Global Public Health — concludes that people on private wells are more likely to get sick from their water than those on community systems, such as municipal utilities.
People who live in counties with high poverty rates are also more at risk, as are residents of rural mountain areas. In Columbus, Martin, Caswell, Yancey and Macon counties 20 to 27 percent of all ER visits related to GI problems were linked to contaminated private wells.
These inequities also present environmental justice issues. Residents may not have health insurance — or be underinsured. And some rural counties don’t have emergency rooms, which means some people could be forced to tough out a serious illness at home.
Total coliform and E. coli were the main bacterial culprits. Elevated levels of total coliform is a signal, like a dead canary in a coal mine, that something more serious is amiss.
From the study:
The presence of total coliforms in groundwater indicates that microorganisms from surface water have been able to reach the aquifer and a more rigorous monitoring should begin for other microorganisms (pathogenic) which might also reach the aquifer. When fecal indicators are detected, anything can happen, and will happen, with potential serious public health implications.
Nearly 36 percent of the more than 16,000 private well samples collected from 2007-2013 tested positive for total coliforms; 1.37 percent did so for E. Coli.
In comparison, only 0.4 percent of the nearly half million samples from public water systems contained total coliforms; even fewer, 0.08 percent of 72,000 samples tested positive for E. coli.
Since July 1, 2008, newly constructed private wells have to be permitted and undergo water quality testing when they are installed. However, wells built before that date have no such requirements; nor are subsequent tests for the new wells. Worse yet, the article points out, there are no requirements to treat private well water if contamination is detected.
The statewide annual cost of these ER visits is $39 million. But about 2,900 of these ER visits could be avoided if just an additional 10 percent of the state’s private well households were connected to public water systems.
And over 30 years, about the time it takes to pay off a municipal bond, the net financial savings of connecting these households is an estimated $78.1 million. That’s a lot of Pepto-Bismol.