Two recent developments regarding contaminants in private well water in Connecticut point to one uncomfortable truth:

There very well may be pesticides and naturally occurring nasty substances in private wells — which are used by 15 percent to 20 percent of Connecticut residents — but we don’t really know what’s there, and there’s nothing in state law right now that would fundamentally change that.

State and national officials concede this following recent revelations of pesticide contamination of private wells in Stamford and an unrelated examination by the U.S. Geological Survey of naturally occurring potential well water contaminants throughout New England

Connecticut’s state health code requires private wells to be tested only when they are built. And that’s only for basic drinkability covering bacteria, color and a few other factors. Local health officials can require additional tests. Some do if their areas have a history of things like farming with heavy fertilizer and pesticide use, knowledge that toxic substances were dumped, or indications of contamination from wells that are used for public supply, which are subject to federal requirements for testing and treatment.

Beyond that, said Brian Toal, an epidemiologist with the Department of Public Health: “You’re on your own.

“If you have a private well, you’re in charge of own water system,” he said. “It’s your personal responsibility to see that it’s safe.”

But despite universal and longstanding admonitions from Toal — and from just about every state and local health and environmental official plus water and geology experts — that homeowners test their wells regularly, it’s widely believed that few owners ever test their wells, let alone do it regularly. That means even though it’s easy to filter out virtually any contaminant that could turn up in drinking water, many people’s water may be tainted.

But those same officials and experts concede, even if people did test, with hundreds of potential contaminants and often little knowledge of what might have occurred in an area decades earlier, it’s not always clear what they ought to be testing for.

“You don’t know,” said Gary Robbins, a hydrogeologist at the University of Connecticut, echoing a common opinion. His solution: Just filter your water if you’re on a private well.

“It would be nice if people did testing every year,” he said. “But if you live in area where other people have water wells and septic fields, you don’t know what they’re putting down their toilets. Assume you’re vulnerable; protect yourself.”

Many contaminants can be handled by whole-house activated charcoal filters. Others require individual under-the-sink filters that use reverse osmosis to clean water. In some cases, when the contaminant is a gas, an aeration system is necessary. Filters can be expensive, and most need regular maintenance and replacement. Dirty charcoal filters can promote bacteria growth, yet another potential drinking water hazard.

“It’s risk versus expense,” Robbins said. “You’d think the public would jump on this and want to know. But they don’t want to know because of the value of their homes and real estate.”

Natural contaminants

It’s well-known in the scientific community that Connecticut’s aquifers, which feed the wells, are subject to a host of natural contaminants. Most of the region sits on what geologically is considered ancient bedrock that can emit dangerous substances such as arsenic, uranium, radon, radium, manganese, fluoride and more. All can end up in groundwater.

The new USGS data, compiled from 1995 through 2007, shows some of these substances to be more widespread and more frequently at levels higher than are safe for human consumption than was previously realized. It also shows Connecticut with fewer problems than other parts of the region.

Groundwater can also absorb any number of surface substances such as road salt and volatile organic compounds (VOCs). Among the most common VOCs here, also noted in the USGS data, is methyl tertiary butyl ether, MTBE, which was added to gasoline for many years and often spilled or leaked from underground storage tanks, compounds from dry cleaning and myriad substances from industrial operations.

And then there are an uncalculated, and pretty much incalculable, number of pesticides, herbicides, insecticides, fertilizers and other substances that were used for decades that are still in the ground.

In many cases with these, as well as VOCs, the dangers of the substances weren’t recognized until later, a situation often compounded by people applying them improperly, storing them poorly or dumping them in landfills and pouring excess onto the ground.

USGS data show pesticide contamination to be minimal, and experts agree that naturally occurring contaminants pose the greater risk to drinking water. The legacy of pesticide use, however, appears to be the source of Stamford’s problem where two substances — Dieldrin and Chlordane — were found in a high percentage of wells tested over the last couple of years.

Both were insecticides widely used to treat termites in particular, especially in agricultural areas. The north part of Stamford where they’ve been found was such an area. Both chemicals were banned by the Environmental Protection Agency in the late 1980s after being declared carcinogens some years earlier.

Both were also known to remain in soil for a long time, which is where they were typically applied around the base of wood structures. But neither was thought to be especially water soluble, so the fact that they’ve turned up in drinking water is surprising to some.

“It’s still sort of a new finding for us,” Toal said.

But not everyone.

“If you look at Stamford, with a very high density of houses; all have wells; all have septic fields at shallow depth,” Robbins said. “It’s not surprising that we have this type of problem.”

And it’s especially unsurprising to Joseph Kuntz, a chemist by training who for 33 years has been with Stamford’s Health Department lab where he handles environmental issues.

Test every well?

Dieldrin and Chlordane turned up in a couple of water samples taken by the Department of Environmental Protection in the mid-1990s. Those homes were given filters, but no further investigating was done. Water contamination monitoring tended to focus on the old Scofield dump, at which Kuntz found high levels of PCBs and DDT, but no Dieldrin or Chlordane.

Kuntz is something of a lone voice in believing that the Stamford situation portends a statewide problem from these substances, so he suggests testing every well in the state for them.

“There’s no way for us to go back in time 30 years ago and see what happened,” he said. “We are dealing with an issue of what we used to use it for, how we used to use it, and how we disposed of it.”

What’s at risk, he said: “I think the whole world is.”

But not everyone does.

“At some point you have to give people a reasonable list of things to test for,” said Toal, who confirmed the state is evaluating whether to begin widespread Dieldrin and Chlordane testing. “If we find pesticides that are a problem, we have to make recommendations judiciously.”

Bill Warzecha, a supervising environmental analyst at the Department of Energy and Environmental Protection, said he recommends testing in the most vulnerable areas. “Do that,” he said. “Rather than steps like telling everybody to go out test their well water for pesticides.”

Geologists and hydrologists point out that the depth of Connecticut’s aquifers varies and that shallower ones — like those in Stamford — tend to be most prone to surface contaminants. They also point out that if the bedrock is solid, substances don’t move much.

But in many places, including Stamford, the bedrock is vertically fractured, opening up fissures that act like pipes and can easily move undesired contaminants directly into groundwater. The depth of the layer of glacial deposits and the types of soils also affect whether and how contaminants move.

“You need a source and you need the right conditions,” said Joseph Ayotte, a New Hampshire-based USGS hydrologist and co-author of the study. And he noted that the concentrations of contaminants that end up in groundwater do not correlate to their concentrations in rocks.

On the other hand, he said: “The fact that Dieldrin shows up long after it’s banned doesn’t surprise a groundwater hydrologist.”

Issues elsewhere

Dieldrin and Chlordane problems have come up before. In Union they were found in a well in 2008 that served a school. Dieldrin contamination in Florida well water brought out environmental activist Erin Brockovich last year.

Local health officials in Connecticut universally and prominently recommend water testing, with easily accessible information on their websites. Most are vigilant about what could be a problem in their area.

In the North Central Health District, which covers the tobacco-farming region of Enfield and Windsor, new wells have to be tested for ethylene dibromide (EDB), a pesticide used on tobacco before its ban in 1983, and for VOCs. The Farmington Valley District requires VOC testing, and the Eastern Highlands District requires arsenic testing. All said they had found very little contamination.

A uranium problem in a public supply well in Madison did not result in additional testing recommendations.

But there is no statewide database of contamination information and tepid legislative efforts to have more testing — mainly for VOCs — have never gained traction. Lending institutions sometimes require tests when they finance purchases of homes with wells, but even though there is a provision in the health code to collect that data, it’s not clear that’s actually happening.

Many point to New Jersey as a model Connecticut should consider. For the last 10 years, New Jersey has required extensive private well water testing whenever property with a well is sold. The information is posted online, making it easy for well owners in those areas to get an idea of whether they’re at risk.

“I think it makes a lot of sense to do that,” said David Brown, a former Centers for Disease Control and Connecticut health official now with the consumer advocacy group Environment and Human Health Inc. He favors a “more rational” system and recommends testing aquifers instead of individual wells.

If he had a well. “I would test every six months if I could find a way to test cheaply,” he said. “If I could find a really good reliable filtering system, I would put it on anyway and drink it.


Jan Ellen is CT Mirror's regular freelance Environment and Energy Reporter. As a freelance reporter, her stories have also appeared in The New York Times, The Boston Globe, Yale Climate Connections, and elsewhere. She is a former editor at The Hartford Courant, where she handled national politics including coverage of the controversial 2000 and 2004 presidential elections. She was an editor at the Gazette in Colorado Springs and spent more than 20 years as a TV and radio producer at CBS News and CNN in New York and in the Boston broadcast market. In 2013 she was the recipient of a Knight Journalism Fellowship at MIT on energy and climate. She graduated from the University of Michigan and attended Boston University’s graduate film program.

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