Climate-driven flooding poses well water contamination risks

 

Stefanie Johnson's farmhouse in Blandinsville, Illinois, was without safe drinking water for nearly two months after a record-setting Midwestern downpour that devastated thousands of houses and businesses.

 

Floodwaters flooded Johnson's well, turning the water a dirty brown and forcing her, her husband, and their two small children to rely on store-bought supplies. Testing revealed microorganisms, including E. coli, which can cause diarrhea, even after the silt was gone. Water was boiled for drinking and cooking in the family. Showers were a welcome sight at the YMCA.

 

“I was pretty strict with the kids,” said Johnson, who works with a private well protection program at the local health department. “I’d pour bottled water on their toothbrushes.”

 

Though estimates vary, roughly 53 million U.S. residents — about 17% of the population — rely on private wells, according to a study conducted in part by Environmental Protection Agency researchers. Most live in rural areas. But others are in subdivisions near fast-growing metro regions or otherwise beyond the reach of public water pipes.

 

While many private wells supply clean water, investigations have discovered that the lack of oversight and treatment provided by bigger municipal systems may expose some users to health concerns such as bacteria, viruses, toxins, and lead.

 

Risks are elevated after flooding or heavy rainfall, when animal and human feces, dirt, nutrients such as nitrogen and other contaminants can seep into wells. And experts say the threat is growing as the warming climate fuels more intense rainstorms and stronger and wetter hurricanes.

 

“Areas that hadn’t been impacted are now. New areas are getting flooded,” said Kelsey Pieper, a Northeastern University professor of environmental engineering. “We know the environment is shifting and we’re playing catch-up, trying to increase awareness.”

 

Pieper is one of the scientists checking wells and educating people in storm-prone areas. She claimed that when Hurricane Harvey flooded the Texas coast, sampling of more than 8,800 wells in 44 counties revealed average E. coli levels nearly three times higher than normal.

 

Following Hurricane Ida in Mississippi in 2021, a sampling of 108 wells revealed a similar increase in E. coli tests. After Hurricane Florence in 2018, other studies found higher levels in North Carolina.

 

The next year, Nebraska was flooded due to above-average snowfall and a March storm. Dams and levees were breached. When the surrounding Platte and Elkhorn rivers overflowed, Fremont, a community of more than 25,000 people, became an island.

 

The municipal system continued to supply drinking water but some nearby private wells were damaged or contaminated. Julie Hindmarsh’s farm was flooded for three days, and it took months to make the well water drinkable again. At times, the cleanup crew wore protective suits.

 

“They didn’t know what was in that floodwater,” she said.

 

CONTAMINATION RISK

 

Groundwater is often a cleaner source than surface supplies because soil can provide a protective buffer, said Heather Murphy, an epidemiologist at the University of Guelph in Canada. But she said that can give well owners a false sense of security, leading them to forgo testing, maintenance and treatment.

 

“There’s a big misconception that it’s underground, therefore it’s safe,” said Murphy, who estimates 1.3 million cases of acute gastrointestinal illness in the U.S. are caused annually by drinking untreated water from private wells.

 

Old, poorly maintained wells are especially vulnerable to floodwaters entering through openings at the top. “It just runs right in and it’s full of bacteria,” said Steven Wilson, a well expert at the University of Illinois.

 

It doesn’t always take a flood or hurricane to pollute wells. Industrial contamination can reach them by seeping into groundwater.

 

Around 1,000 residential wells in Michigan’s Kent County were tainted for decades with toxic per- and polyfluoroalkyl substances, or PFAS, in landfill sludge from footwear company Wolverine World Wide. The pollution, discovered in 2017, spurred lawsuits and a $69.5 million settlement with the state that extended city water lines to affected houses.

 

“We thought we were getting this pristine, straight-from-nature water and it would be much better for us,” said Sandy Wynn-Stelt, who has lived across from one of the dump sites since the early 1990s.