Is My Town Affected?

About pyrrhotite in New England

Pyrrhotite is an iron sulfide mineral found in certain aggregate quarries. When used in concrete foundations and exposed to water and oxygen, it slowly expands and causes the concrete to crack and crumble — a process that can take 10 to 30 years to become visible.

The primary source of pyrrhotite-contaminated concrete in Connecticut was the Becker's Quarry in Willington, CT, which supplied aggregate to concrete producers serving much of northeastern Connecticut from roughly 1983 to 2015. Homes within a 20-30 mile radius of the quarry are at highest risk, but pyrrhotite-affected foundations have been reported across the state.

Connecticut — Confirmed Hot Spots

Connecticut has the most well-documented cases, tracked by the Connecticut Coalition Against Crumbling Basements (CRCOG) and the Connecticut Foundation Solutions Indemnity Company (CFSIC). As of mid-2026, thousands of homes have been identified with pyrrhotite-related foundation deterioration.

Heavily affected towns include: Ashford, Bolton, Brooklyn, Columbia, Coventry, Ellington, Mansfield, Somers, South Windsor, Stafford, Tolland, Union, Vernon, Willington, and surrounding communities in Tolland, Windham, and Hartford counties.

Case counts are from CRCOG data. Verify specific town counts via the interactive map above. Last updated: June 2026.

Massachusetts — Confirmed, No Public Count

Massachusetts has confirmed pyrrhotite cases, particularly in Hampden and Worcester counties near the Connecticut border. However, Massachusetts does not maintain a centralized public case count, so precise numbers are unavailable. If your Massachusetts home was built with concrete sourced from northeastern Connecticut between 1983 and 2015, it may be at risk.

Watch areas: Brimfield, Holland, Monson, Palmer, Southbridge, Sturbridge, Wales, and surrounding towns in southern Worcester and eastern Hampden counties.

Rhode Island & New Hampshire — Watch Zones

Rhode Island and New Hampshire share the same geological formations that produced pyrrhotite-bearing rock in Connecticut. As of this writing, neither state has confirmed residential hot spots. These are designated watch zones — areas where homeowners should be aware of the issue and include a pyrrhotite check in any foundation inspection, but where confirmed residential cases have not been publicly documented.

What to do if your town is on the map

1. Don't panic. Pyrrhotite damage takes years to develop. Early detection gives you options.
2. Look for signs. Read our 7 warning signs guide and inspect your foundation.
3. Get tested. Learn how to test your foundation for pyrrhotite before you take any action.
4. Stay informed. Sign up for our newsletter below — we track policy changes, funding updates, and deadlines.