Thousands of Connecticut residents whose homes are threatened by failing concrete foundations got some encouragement this week with the visit of U.S. Housing and Urban Development Secretary Ben Carson, who expressed hope that federal assistance might be possible.

As many as 34,000 homes in eastern and north central Connecticut could be at risk because aggregate used in the concrete contained a pyrrhotite, a mineral that in time causes the concrete to crack and degrade. Homeowners face bills of as much as $200,000 to repair the damage, and until now help has been slow in coming.

But on Monday, Carson toured the home of a couple in Willington, Connecticut, whose basement began developing cracks three years ago. Damage has since spread upstairs, and now Maggie and Vincent Perracchio fear the house could collapse, The Associated Press reported.

The Perracchios and other Connecticut families facing the same problem have been largely turned away by insurance companies. Although the state has started a fund to help homeowners that will generate $10 million a year, the federal government until now hasn’t offered to help; the Federal Emergency Management Agency has turned down the governor’s request for a disaster declaration more than once, according to The Hartford Courant.

Carson had a different message Monday.

“As compassionate individuals, we all should care about our neighbors,” Carson said, according to the AP. “That was one of the reasons that this country succeeded early on, because people cared about each other. As long as we adopt that feeling of truly caring, we will solve this problem.

“I can’t imagine what it’s like for the homeowners,” he said. “By working together with the other federal agencies, with Congress, with the state and with the local officials as well as the private sector — I can’t emphasize enough the fact that this is something that impacts a lot of people — and the solution really needs to be relatively comprehensive and involve all those different entities.”

Members of the state’s congressional delegation and Lt. Gov. Nancy Wyman, a Democrat, accompanied Carson on the tour of the couple’s home. U.S. Sens. Chris Murphy and Richard Blumenthal, both Democrats, are sponsoring legislation that would provide $200 million in aid over five years, half of which would come from Housing and Urban Development.

A long-simmering problem

The rock aggregate bearing pyrrhotite, an iron sulfide, was mined in a Willington, Connecticut, quarry and used in ready-mix concrete supplied by the J.J. Mottes Company for homes built in the 1980s and 1990s, according to the Connecticut Coalition Against Crumbling Basements (CCACB). The state estimates that as many as 30,000 houses could be affected, although the number of homeowners who have filed formal complaints is far lower.

It can take years for the problem to surface. The cost of replacing a foundation can exceed the value of the house, leaving homeowners with crippling financial problems. Insurance claims by many homeowners have been rejected.

The J.J. Mottes company, which supplied the concrete, has said the problem is “an installation issue.”

In addition to the cluster of pyrrhotite-induced problems in Connecticut, more than a thousand buildings in Quebec near Trois-Rivières showed similar structural issues. The provincial government has established a website explaining the problem to homeowners and set aside more than $50 million to help pay for repairs.

The American Geosciences Institute says that structural damage to buildings due to pyrrhotite or pyrite, another iron sulfide, have been observed globally since the mid-1950s. In the U.S., “pyrite-induced swelling” has been observed in Ohio, West Virginia, Pennsylvania, Missouri, and Kansas, according to the institute.

Ben Mandler, a researcher and program supervisor at AGI, said in an email that many of the problems associated with pyrrhotite occur because the mineral is present in backfill used around new foundations, not because it’s found in the construction materials themselves. This is the case with most of the examples mentioned on the AGI website.

“But there are some cases similar to the Connecticut case, where concrete damage has been linked to the presence of pyrrhotite in the aggregate mix used to make concrete,” he added. “This has been observed in some dams in Spain, for example, and likely elsewhere to some extent. I’m not aware of this being a major problem in concrete used for foundations elsewhere in the United States.”

Reports from Massachusetts

The ready-mix plant where the Connecticut concrete was made is close to the Massachusetts state line. Eighteen months ago, the Massachusetts attorney general’s office had not received any consumer complaints about faulty concrete in the area. But this week, the office said it has received two complaints about concrete provided by the J.J. Mottes company. The office didn’t provide any further details.

In addition, the Massachusetts state senator whose district includes a number of communities in the south central part of the state sponsored an amendment to the Senate budget calling for the establishment of “a commission on crumbling concrete foundations.”

Lesser said in a tweet last month that the budget amendment had passed. A similar amendment was offered in the House, but apparently was not approved, so the fate of the study commission rests with the conference committee working on a compromise budget bill.

New interest from the concrete industry

There are currently no known national standards limiting the amount of pyrrhotite that can safely be included in concrete, but the American Concrete Institute, an industry trade group, says that it is focusing new attention on the problem.

In an email, Matthew Senecal, the institute’s director of engineering, said that an ACI committee has received approval to write a technical note about pyrrhotite, a process that could take a year to complete. Separately, he said, there have been attempts to write an article about the issue for the institute’s magazine, Concrete International, but there hasn’t been enough technical data on file to support it.

“I think the failure mechanism is fairly well understood,” Senecal said. “What seems to be less understood is the accuracy in detecting pyrrhotite; what environmental conditions lead to activation of the mechanism; and what material properties or environmental conditions control the rate of the mechanism. I have not seen any research in the U.S., but Canada has had similar problems in the regions around Quebec.”