By Carol Bartold, Senior Reporter
Jul. 18, 2018: A recent development in Consolidated Edison's effort to upgrade and repair aging gas mains along Midland Avenue from Winter Hill Road in Tuckahoe to Library Lane in Bronxville has raised concern among village residents who live in the Midland Avenue area.
The utility has indicated that a section of new 16-inch steel pipes, which will ultimately replace all 12-inch cast iron pipes currently in place, may not have been properly cleaned and scoured before installation. As a result, Consolidated Edison determined that natural gas flowing to residences already connected to the new main does not contain sufficient mercaptan, the chemical that lends a sulfuric odor to natural gas and allows detection of gas leaks.
According to Bob McGee, Consolidated Edison spokesperson, a section of the newly installed pipes absorbed enough mercaptan to render the gas flowing through them odorless. He stated that on June 30, the utility began a procedure, known as purging, that will allow the utility to achieve the level of mercaptan needed in the natural gas to ensure safety. Purging involves forcing an increased flow of gas through the pipes to eliminate the odorless gas and pump in a new supply while adding mercaptan to that new supply until the level needed to make the gas detectable is achieved. The natural gas eliminated by purging is continuously released into the atmosphere.
Resident Gretchen Pingel reported that the ongoing process has subjected the neighborhood to increased noise and disruption, not only from the purging itself but also from work crews and idling vehicles being onsite day and night. "It is amazingly inefficient, expensive, and wasteful," she said.
McGee stated that, while Consolidated Edison is expediting the work, there is no estimated completion date. "If there were a different way to do this, resulting in greater savings, we'd do it," he said. "What we're doing is state of the art in these regards." He cited the decreased flow of natural gas due to summer's lower demand as one factor that made purging necessary to solve the mercaptan problem.
Work on the overall project began in January at Winter Hill Road and has proceeded into Bronxville, resulting in ongoing construction work on Midland Avenue. McGee noted that initial work yielded proper mercaptan levels but that readings on the section currently undergoing purging revealed a problem. "We need to be sure the mercaptan takes hold," he said.
Bronxville Village Administrator Jim Palmer has indicated his insistence that Consolidated Edison properly prime all steel piping to be used for the next section of work so that purging can be avoided. "I will not have them start installation of the next section of 16-inch pipe until the first section can be closed up and purging is complete," he said. "They will be better prepared for the next section of pipe."
Pictured here: Midland Avenue in Bronxville during Con Ed's upgrading and repairing of aging gas mains.
Photos by A. Warner