Main Street in Durham is about as quintessential small-town Connecticut as it gets. Colonial-era homes, churches, schools and town buildings are neatly arranged along Main Street in much the same way as they have been for a century or more.
Flags line the street for summertime.
What is not plain to the eye is that the entire area is a federal Superfund site: an area that has been designated for cleanup of toxic materials by the federal Environmental Protection Agency. A pair of factories on Main Street — Durham Manufacturing, founded in the 1920s, and Merriam Manufacturing, which dates back to the 1850s — manufactured metal boxes and at one time improperly disposed of chemical contaminants into nearby streams and lagoons. (Durham Manufacturing is still in operation, while the Merriam Manufacturing building burned down in 1998.)
When the Superfund site was declared in the late 1980s, the original target of the cleanup was a chemical solvent called 1,1,1-trichloroethane. As testing methods have become more sophisticated in recent years, a new culprit has emerged. A potentially cancer-causing chemical compound used in the degreasing of industrial machines, 1,4-dioxane, has become a focus not only at the Durham site, but at sites all over Connecticut.
The compound has been part of industrial processes for decades, and the EPA has classified it as a “likely carcinogen,” though not enough testing has been done on the health effects it has on humans. Because the EPA has not set a federal safety level for 1,4-dioxane in drinking water, it falls to states to set their own standards.
What is 1,4-dioxane? A colorless, odorless synthetic chemical compound used in industrial degreasing operations. Because it doesn’t bind well to soil, it can migrate in groundwater and doesn’t biodegrade easily, according to environmental analysts. There is no federal maximum contaminant level.
Where is it? In wells and water systems across the country. The two most prominent concentrations in Connecticut are at the federal Superfund site in Durham and the state Superfund site in the Tylerville section of Haddam.
What are the health effects? In short, not enough is known. The compound is known to cause cancer at high doses in mice and rats, but relatively little is known about the health effects on humans. The EPA classifies it as “likely to be carcinogenic.”
Though the compound has been used in industrial-degreasing operations — such as those used in the fabrication of metal boxes — the compound’s chemical properties make it difficult to detect. Unlike oil, which remains separate from water, 1,4-dioxane is completely soluble in water, making containment difficult. It is also “relatively resistant to biodegradation in the subsurface” and in groundwater, according to the EPA.
As part of the cleanup process, 54 homes with affected wells received granular activated carbon (GAC) filters, meant to address the presence of 1,1,1-trichloroethane. The discovery of 1,4-dioxane in 2003 and 2004 in certain wells presented a new difficulty, as it is not sufficiently filtered by GAC devices.
As the culmination of a nearly 30-year cleanup and remediation process at the Durham Superfund site — which contains some 50 homes, 10 of which receive a bottled-water allocation from the EPA — plans are underway to install a water main to pipe in clean water from Middletown to Main Street. The EPA still regularly monitors water at some 17 homes within the site.
Lynn and Gene Riotte, who have lived for 23 years just a few doors from the former Merriam Manufacturing site, say no testing has been done at their Main Street home for at least 10 years. They have been aware of TCE since moving in, and their well was tested for it, they say, but they had been unaware of 1,4-dioxane until being informed by a reporter for this story. Jim McLaughlin, who has lived across the street from the Riottes since 1968, was also unaware of 1,4-dioxane. George Gorton, who lives on the other side of the Merriam site from the Riottes, says he has his water tested routinely for 1,4-dioxane. “It makes me want to have the water tested again,” says Lynn Riotte. Both the Riottes and McLaughlin live within the area that has been selected for the water main, they live outside the Superfund site itself.
The town of Durham had its first public information session on 1,4-dioxane back in 2004, when various state and federal departments presented and the water main project was first proposed. According to Durham First Selectman Laura Francis, it was at this point that a planning team came together involving the state departments of Public Health and Energy and Environmental Protection, the town of Durham and the city of Middletown. “We have met, either by phone or in person, pretty much once a month since then,” she says. Jing Chen, an environmental analyst at DEEP and the case manager for the Durham site, says there is no effective treatment method for 1,4-dioxane at the household level.
While the water main will provide a permanent solution by providing regularly monitored and treated water to Durham, 1,4-dioxane is a problem in many parts of the state. The other major site for the compound in Connecticut is the state Superfund site in the Tylerville section of Haddam. Shannon Pociu, another DEEP environmental analyst and a project manager at Tylerville, is working on getting a public water main extended into the Tylerville area from Chester. According to Pociu, there are some nine homes in Haddam that receive bottled water.
Since 2013, the DPH has maintained an action level (the point at which action must be taken to address the issue) for drinking water at 3 parts per billion (ppb); DEEP, which monitors groundwater levels, adopts the same standard. According to an email from Christopher Stan in the DPH’s communications department, the most recent data on the carcinogenicity of the compound was a 2009 study that shows cancerous effects on the liver in mice and rats. “The epidemiology literature on the health effect of 1,4-dioxane is inadequate to evaluate effects in human populations,” he writes.
Connecticut’s drinking-water action level of 3 ppb is based on a 1-in-100,000 cancer risk, according to Stan. Some states, such as Massachusetts and New Jersey, regulate the compound at a more-stringent .35 ppb, which is based on a 1-in-1 million risk level for cancer. Each state regulates 1,4-dioxane levels in its own way, which means that levels vary state to state and trigger different procedures.
While no federal standard exists, 1,4-dioxane was included in the EPA’s third round of nationwide testing of public water systems for a battery of as-of-yet-unregulated contaminants across several years, the results of which were released in January of this year. According to an analysis of the data published in the journal Science of the Total Environment in April, 6.9 percent of the nearly 5,000 public water systems tested registered levels of 1,4-dioxane above the .35 ppb level.
In Connecticut, water systems in Wallingford, Manchester, Meriden, Southington and Cromwell contained 1,4-dioxane. All but Wallingford tested below the state action level. The Wallingford water treatment station at Oak Street measured 3.6 ppb in July 2013. According to Stan, the source of 1,4-dioxane in the Wallingford system is still unknown, but “Wallingford was able to readjust the operation of the wells and maintain the levels of 1,4-dioxane near 2 ppb at the entry point to the system for the past three years,” he writes.
A clarification has been added about the location of the homes of the Riottes and Jim McLaughlin, as well as the frequency of testing of George Gorton's Well.