UNC Analysis Finds Arsenic, Metals in North Carolina Wells

The water may look clear, but in Wake County, it might contain iron, lead, manganese, arsenic or copper.

A statewide analysis of well data for the past several years found various contaminants in private wells, an area some say needs more oversight.

While most water in cities and towns come from closely monitored municipal water systems, residents on well water are in responsible for their own testing. A state law passed in 2008 requires new wells to be tested, but prior to that there were only testing requirements in 15 out of North Carolina’s 100 counties. Wells built before 2008 have never required testing, even as they rust and age out.

The study was a joint effort between the University of North Carolina Superfund Research Program and the state Department of Health and Human Services, among others.

To complete the study, researchers examined more than 10 years of data collected from private wells. And what they found was surprising, said Rebecca Fry, assistant professor at UNC’s school of Public Heath.

“Through that study, we’re able to identify counties of concern,” she said. “The data really highlight that continued monitoring of environmental contaminants in private wells is definitely prudent. It definitely would be wise for us to be tracking these.”

But tracking private wells statewide is not something the state is funding right now.

What’s in There?
According to the data, Wake County has dozens of wells containing higher levels of copper, iron, lead and manganese.

Because the study uses data culled from multiple sources, the number of wells tested for each of 30 contaminants varies.

For manganese in Wake County, the study cites 2,570 wells, 583 of which tested with levels above the Environmental Protection Agency’s maximum containment levels.

Manganese is a metal element resembling iron. According to a 2010 study, higher levels of exposure to manganese in drinking water is associated with increased intellectual impairment and reduced intelligence quotients in school-age children. Some argue that long-term exposure to manganese in shower water puts up to 8.7 million Americans at risk.

The other metals, too, have negative health effects at certain levels of exposure.

When looking at the chart, one might guess Wake County has higher levels of mercury than anywhere else in the state.

Mercury is a chemical element used in some thermometers, dental fillings and batteries. People exposed to high levels of mercury can suffer from loss of vision, speech or hearing, have trouble walking or experience muscle weakness. In infants, mercury can cause neurological damage.

But although a map of mercury levels in North Carolina makes Wake County look bad, Fry cautions those looking at the maps, which are not based on the number of wells tested. When checking the actual data, it turns out only one well out of 2,104 was found with levels higher than the maximum levels set out by the EPA.

However, the analysis also found something interesting in North Carolina: arsenic.

Of the 63,000 wells tested statewide 1,436 exceeded the EPA drinking water standard for arsenic.

According to the study’s abstract, such numbers indicate “potential areas at increased risk for adverse health outcomes.”

Learn more about the Arsenic study
View Maps of Arsenic Concentrations in North Carolina

The EPA and the World Health Organization say arsenic amounts should be 10 ppb (parts per billion) or fewer.

“For arsenic, there actually are some high levels of exposure in North Carolina on the order of hundreds of parts per billion,” Fry said.

In Wake County, there were only 16 well with exceedingly high levels of arsenic.

Wake County water is very clean, according to Greg Bright, supervisor of Wake County’s Groundwater Program.

In 2003, it was estimated that there were 30,000 wells in the County. Bright estimates that the county has had at least another 2,000 wells installed since, although some of those are irrigation wells.

Wake County has tested 2,705 wells since 2003. In that time, they have never found mercury, and rarely find anything else of concern, Bright said.

“That’s something we just don’t find in our private wells,” he said. “We rarely get a hit on anything; the water is actually really good.”

Why Test?
Although arsenic and mercury aren’t a concern for Wake County residents, having this information is a good first step, Fry said, not only to raise awareness among private well owners, but for future research of environmental exposures, distribution of contamination, and the impact of groundwater on human health.

A well diagram.

“It’s useful as a guide for places where we may want to dig deeper,” she said. “But I don’t think I would use them to highlight areas of concern.”

Mina Shehee, of the North Carolina Department of Health and Human Services, initiated the partnership with UNC to look at arsenic and the other contaminants. She had a hunch there was more to water more than meets the eye.

“Oftentimes people will know things, but sometimes you need to go out and measure them,” she said.

She is using the data to pinpoint areas for study, to make sure something or someone in the area isn’t causing a problem.

“You have to look at each situation and determine the source. But a lot of these things will come from the piping, depending on the contaminant,” she said. “Just because it’s in the water, doesn’t mean that corporation X down the road did it.”

But keeping an eye on well water isn’t just for health officials, Sheehee said. The data demonstrate that private well owners need to be diligent about well maintenance.

More than 50 percent of U.S. households use private water sources for drinking and other uses.

In 1999 and 2000, contaminated private well water in the U.S. caused 26 percent of the drinking water outbreaks that made people sick, according to the Centers for Disease Control and Prevention.

Despite that, prior to 2008, fewer than 15 North Carolina counties, including Wake, had programs to oversee private wells for residents and businesses. The rest tested wells only by request.

A new state law in 2008 required all new wells to be tested and certified by the local health department. However, once a well is certified, testing the private water is solely the responsibility of the well owner. But most well owners don’t think to test the water regularly unless they smell or taste something odd, Bright said.

Older wells can become rusty over time and changes in nearby landscape or construction can affect the water, Bright said. Those changes may not lead to a noticeable change in the water’s taste, color or odor.

“A lot of people kind of let the well and septic go; they don’t think of it as something that’s got to be maintained. A well is somewhat like any other system you have at your house,” Bright said. “At some point in time it may need maintenance.”

More Oversight
Terry Pierce, former director of Environmental Health at the NC Department of Environmental and Natural Resources, said for him, the data highlight a need for more well oversight.

When state law began requiring new wells to be tested in 2008, DENR had a separate division to manage on-site water protection and oversee well testing.

That office was transferred last year to the Department of Health and Human Services, where cuts and attrition have led to one remaining staff member handling well testing oversight, Pierce said.

“What this did is it dumped everything back on the local level,” he said. “And in many cases, the local level is not able to pick up this workload.”

Pierce lauds local well programs, especially those with higher standards than the state, such as Wake County. But in some counties, a permit to construct a well is often issued before the testing is returned, he said.

“The oversight at the state level is lacking; it just doesn’t have staff there,” he said. “It’s not being done the way it really should be.”

Legislation has been proposed in the past to test all wells, but the cost of well testing can run between $250 and $300 per well.

“Unless there is some obvious issue with the water supply, there’s no type of enforcement,” Pierce said.

Prior to his retirement this year, Pierce was working on a database of all wells in the state. His vision was to use that information over time to pinpoint contaminated areas.

“My ultimate goal was to try to get all that test data, which ran through the state public health lab, to look at that test data, statewide to get it in a database. So each time a well was tested … it also gave us an indication of the condition of the aquifer. So when you start getting all these little dots around, you can start seeing where the contamination is.”

Pierce hopes the legislature will someday find a way to fund the program again, because most private well owners just aren’t going to do it.

“People have other uses for their money,” he said. “And even if people can afford to have the testing done, they don’t feel like it’s a priority.”

Sheehee hopes the information gathered in the study will help her prove to both health agencies and homeowners that well testing is just that: a priority.

“Doing well testing is like getting a physical,” she said. “You just can’t tell by looking or tasting that it’s OK. That’s the message we want to get out.”