Columbia Gas of Massachusetts Pilot Capping Project To Clean Up Connecticut River

Dec 15, 2016

The Springfield Gas Light Company, a predecessor company to Columbia Gas of Massachusetts, operated a Manufactured Gas Plant (MGP) to manufacture natural gas from coal from the mid-1800s to the early 1960s east of the railroad tracks along the Connecticut River in Springfield.  During the MGP operation, liquid tars were discharged through pipes and municipal storm drains into the Connecticut River where the exposed tars on the river bottom is hardened tar.

Over the past few years Columbia Gas, under the guidance of the Massachusetts Department of Environmental Protection (MassDEP) conducted extensive investigations in the Connecticut River to determine the most effective way to remove or contain the tar sediments. The remediation process of the affected areas in accordance with the MassDEP’s cleanup regulations began in early December.  The investigations show a two-mile stretch of tar-affected sediment in the area of Riverfront Park to south of the South End Bridge.  In consultation with MassDEP, Columbia Gas proposed to remediate the tar residuals in the river by capping this tar beneath a minimum of 12 inches of clean stone,providing a stable protective physical barrier between the tar-affected sediments and the river bed.

The investigations revealed  the source of the tar sediment is from historic pipe discharges that ceased at least 50 years ago and there is “no significant risk” to human health from the tar under current conditions.

The remediation process will be overseen by AMEC Foster Wheeler Environmental and Infrastructure Inc., and includes placing ten pilot caps in two areas in the river and monitored for effectiveness over the next few years, prior to placing a full-scale cap.  The caps will be installed by J.F. Brennan, an experienced marine contractor. The results of the Pilot Cap Project will then be used to develop a full-scale capping project in the future.

All equipment will be removed from the river before Christmas.