Programmatic and Historic Consulting, Former PSNH Manufactured Gas Holdings

Northeast Utilities (NU) retained GEI to provide historic and programmatic consulting services on the former Public Service of New Hampshire (PSNH) manufactured gas holdings in New Hampshire.

Working closely with environmental managers and attorneys at NU and PSNH, GEI staff conducted detailed reviews of the historical operations of a number of properties and gas works located in Laconia, Nashua, Dover, Keene, and other towns.

The objective of the reviews was to provide documentation of the dates and operations at the individual plants including episodic events that would be useful in negotiations with regulators and previous site owners.

GEI’s work included:

• Review of Sanborn Insurance Maps, Brown’s Directory of American Gas Companies, and Moody’s Investors Manual
• Review of plant records at the Public Utility Commission
• Review of aerial photographs, historic society archives, and community records of the individual facilities
• Interviews with former employees knowledgeable with the plants
• Interviews with town officials
• Historical film and photograph analysis and interpretation
• Summary reports
• Presentation of findings at negotiations

The historic analysis for many of the sites was used to provide a basis for the eventual Phase II site investigations at the gas plants.

At the request of NU and PSNH, GEI presented a half-day seminar to the New Hampshire Department of Environmental Services (NHDES) on the history, investigatory aspects, and remediation of former manufactured gas plant sites. The seminar was well received by the regulators and provided them with a high level of confidence in PSNH’s ability to conduct environmental investigations at the New Hampshire sites. Site investigation based on historical records and land use is now becoming a more widely accepted and required approach to all site investigation in New Hampshire.