About Pyrrhotite
The following letter was sent to the PZC before their vote on the moratorium. It has some important information and links about the pyrrhotite issue in Ashford. Pyrrhotite is the substance that cuased the crumbling foundation issue through out the area. We encourage you to learn about this issue. It should impact land use regulations in AShford going forward.
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June 9, 2023
To the Members of the Ashford Planning and Zoning Commission
Re: Public Hearing: Town of Ashford Planning and Zoning Commission Meeting June 12, 2023.
Article 1, Section 4 Moratorium on Warehouses, Distribution Centers and Research Facilities including Research and Development and Testing Laboratories or Centers.
I support the amendment to Ashford Zoning Regulations for a Moratorium on applications for, and approval of, new truck and freight terminals, warehouse/distribution centers and research and development and testing laboratories or centers throughout the Town, including the Interstate Interchange Development zone, so the Commission can pause to fairly assess and revise its regulations, in keeping with the goals in the town’s POCD.
The recent text amendment proposals in 2020 and 2023 by developers seeking to increase the size of permissible buildings and acceptable uses in the IID zone brought intense focus to the characteristics of that zone and, as a result, much more is now apparent to all about the geology, hydrology, and other aspects of the site that raise concerns about the kinds of development that would be acceptable there. Also apparent is how much is not known about the site and its characteristics. The proposed moratorium would give our town the chance to fully understand not only what kind of land we are dealing with but also how we should deal with it. It is not just “vacant land”.
The most alarming information about the IID zone that has surfaced is about the bedrock geology of the site, bedrock that contains pyrrhotite. Pyrrhotite is the mineral that was used in concrete for foundations of thousands of homes and other buildings in Connecticut and Massachusetts, foundations that cracked and crumbled and have resulted in enormous expense, heartache, and loss. Excellent information about the dangers of pyrrhotite (called a geohazard) and mapping of where this kind of bedrock is known to occur in CT (e.g., in Ashford) can be found on the following website: https://portal.ct.gov/DEEP/Geology/Pyrrhotite-and-Crumbling-Concrete
From this website, “Beyond the hazard of sulfides such as pyrrhotite in concrete, blasting and rock crushing operations involving sulfide minerals can have an impact on environmental quality by causing acid drainage, which is detrimental to drinking water quality and can have ecological impacts.”
A Guidance Document is available: Guidance Document for Evaluating Potential Hydrogeologic Impacts Associated with Blasting and Development Activities, dated December 2019.
DEEP Guidance Document- https://portal.ct.gov/-/media/DEEP/site_clean_up/potable_water/Blasting-Guidance-Dec2019.pdf
developments, road construction projects, or quarries where significant earth removal and/or blasting activities are likely to occur. Because of those types of activities, there is concern for possible negative impacts to the quality and quantity of water in neighboring drinking water wells, as well as other environmental factors such as erosion, sedimentation, and decreased surface water quality conditions.
One of the primary concerns is acid rock drainage (ARD), which is a natural process, but can be exacerbated when rock is crushed and used for fill or other purposes that expose the freshly crushed rock to precipitation. ARD is caused by the presence of bedrock containing high levels of iron sulfide (which is present in Eastern and Western Highlands and sometimes the central valley of CT), especially such rock that is freshly exposed or crushed and has been subjected to the elements/precipitation. Under these conditions, there is an elevated risk for mobilizing naturally-occurring iron, manganese, and sulfur, which may adversely affect groundwater and drinking water quality. In addition, increased mobilization of arsenic, uranium and/or radon can occur in areas where these naturally-occurring minerals are present in the bedrock formation.”
The guidance document provides specific procedures that should be followed by land use officers and by developers before, during, and after suspect bedrock is disturbed. It also lists resources for evaluative expertise. Ashford’s IID zone site is a hillside and any development for large buildings will require blasting, major disturbances to the bedrock, and likely release of the “geohazard” pyrrhotite and other sulfides if indeed they are present as suspected.
Who knew?
The fact that the IID zone is home to the pristine wetlands and watershed of a major river that supplies water to several downstream towns and neighboring wells makes the potential of pollution damage by blasting/disturbance of pyrrhotite/sulfide-containing bedrock particularly alarming. These natural resources are worthy of the best possible stewardship to protect a crown jewel of our town. Our zoning regulations must reflect the care that must be taken to develop responsibly in and around these resources. Our regulations must be informed, detailed and precise, and monitoring of development at all stages by independent experts must be done to avoid reckless construction practices.
I hope the Commission will adopt some version of this moratorium and embrace it as an opportunity to craft and hone our zoning regulations so the IID zone can be developed in a thoughtful and responsible manner.
Thank you for your work for our town, Christine Acebo
91 Perry Hill Road
Ashford, CT