Chapel Street MGP

The Site is the location of an old plant that operated from the 1860s to 1960. The plant, which is no longer present, made (manufactured) gas from coal and oil for use in street lighting and fuel for homes and businesses. The Site is located at 347 Chapel Street and 259 East Street in the City of New Haven, and is bound by Chapel Street to the South, the Mill River to the east, a parcel owned by others to the North, and East Street to the West.

The Site is approximately 14.6 acres and the footprint of the former MGP is comprised of two parcels, one owned by SCG. and the other owned by another party.  SCG owns the property located at 347 Chapel Street and leases it for the bulk storage of salt and aggregate supplies & materials.  The other parcel is at 259 East Street.

Since SCG formerly operated a MGP at the site, it is responsible for the environmental impacts of the operations.  In 2008 and 2014 coal tar residuals (from historical MGP operations) were discovered along the shoreline of the Mill River as a result of damage to on-site stormwater drains.  These discoveries led to SCG repairing, rerouting, and eventually plugging the storm drains, and placing containment and absorbent booms along the shoreline.  SCG subsequently entered into discussions with CT DEEP and in January of 2018 CT DEEP issued SCG a Consent Order (SRD-231) to determine the nature and extent of impacts from historical MGP operations both on the land area and within the Mill River, and to remediate impacts from the former MGP operations.  A Consent Order is a formal agreement with CT DEEP that requires SCG to conduct the investigation and remediation. 

The primary impacts found in the ground on the land side have been MGP-related and consist of coal-tar and coal tar residuals.  These impacts contain semi-volatile organic compounds (SVOCs), a subset of which are also referred to as polycyclic aromatic hydrocarbons (PAHs). Volatile organic compounds (VOCs) were also found; the primary detected VOCs have been benzene, toluene, ethyl-benzene and xylene, commonly referred to as BTEX.  Coal-tar, PAHs, and BTEX compounds are typically found on former MGP sites. Additionally, metals such as arsenic, lead, and selenium were also detected, which are commonly associated with urban fill and early industrial activity and are typical of locations that have historical industrial uses and development.

As with the land side soil samples, coal tar, PAHs, BTEX, and metals (such as lead, copper, chromium, and zinc) have been detected in Mill River sediment samples. PCBs were also detected in sediment samples. Coal-tar, PAHs and BTEX are typically observed at historical MGP sites, with PAHs and BTEX also typically observed in urban as settings, as such, a portion of the PAHs & BTEX and the PCBs are likely related to a variety of “urban background” non-point sources and other historical industrial activity.  Similarly, the detection of some metals may be related to the MGP operations as well as other industrial uses along the River.

Intermittently, sheen occurs on the water surface adjacent to the Site, particularly at low tide.  The sheen originates from coal-tar residuals in sediments along the shoreline.  SCG maintains a series of booms to help contain the sheen.  SCG has a contractor perform regular inspections, perform boom maintenance, and provide response to contain a sheen if it goes  beyond the booms. Also, SCG prepared and follows a Mill River Pollution Prevention Plan for the Site.  This plan was reviewed and approved by CT DEEP in June 2018.  

The project is currently in the investigation phase.  To date investigations, including the collection of soil, ground water, surface water and sediment samples have been completed in many areas of the Mill River adjacent to the Site and at various locations around the property (land side). Since the Site is still actively used to store bulk materials, SCG works with the tenant to identify opportunities to assess areas of the Site when they become accessible.

Yes.  Pursuant to the Consent Order SCG has Identified and hired a Licensed Environmental Professional (LEP).  The LEP is responsible to oversee the work, ensure data quality, verify that conditions of the Consent Order are being met and work with the parties involved with the Site.  The LEP for this Site is Haley & Aldrich, Inc.  (H&A).  SCG alongside of H&A will also hire subcontractors, as required to support the investigation of the site.  The subcontractors will allow both SCG and H&A to develop comprehensive investigation reports for CT DEEP review and to use as a guide to find an appropriate and feasible remediation solution.

Currently it is very difficult to determine when remediation will be finished since we are still in the investigation phase of the project.  The investigation and remediation work are being performed in cooperation with CT DEEP and follows an established, multi-step process. Following completion of the investigation, an alternatives analysis will be performed to identify possible remedial solutions.  Following selection of a remedial solution SCG will work with CT DEEP on a remedial design and clean-up plan.

The recovery from customers of any costs incurred by SCG, including the recovery of costs for environmental remediation, is determined by the Public Utilities Regulatory Authority as part of PURA’s periodic review of SCG’s rates.

At this time SCG does not have plans for the Site.  Once the remedial plan for the Site is developed and implemented, and the necessary reports and verification documents required to document the remedial actions are complete, the Current use of the property is expected to continue.

Once reports have been approved by CTDEEP, SCG will post them to the website.

Any questions or concerns should be directed to The Outreach Department at 888.303.3773 or via email: outreach@uinet.com