Wastewater lagoon blamed for Exit 4 odor
LONDONDERRY — Something smells rotten in Londonderry.
Whether they live in the area or are simply passing through, folks traveling around Exit 4 off Interstate 93 are keeping their windows rolled up these days, though few seem to know why.
Posters on various social media outlets vented their frustrations this week, wondering if something, anything could be done about the vexing and pungent odor wafting through their windows.
Londonderry resident Cheryl Haas, who travels the highway regularly on her commute to the Windham Town Recreation office, said the odor has gotten increasingly more potent over the past several days. “It just gets worse the closer you get to Exit 4,” Haas said. “A lot of people have been asking about it.”
Other commenters were somewhat less tactful when it came to the matter.
“The sewage smell around Exit 4 is unreal,” Sarah Pomeroy added.
“Is anything being done?” Scott Bonfanti asked. “This is getting ridiculous.”
Londonderry Town Manager Kevin Smith said the smell is from a wastewater treatment facility in nearby Derry.
“Sorry, but there’s nothing we can do about it, other than hold our noses,” Smith said this week.
Tom Carrier, deputy public works director for the town of Derry, said an oxygen deficiency in the water treatment lagoon off Fordway Street, which runs alongside I-93, is the likely culprit of this increasingly stinky spring season.
“We’ve gotten around three-dozen calls about it,” Carrier said on Wednesday.
Wastewater flows into the outdoor lagoon throughout the year, with organic waste settling in as part of the turnover process. During the spring season, as the water gets warmer, wastes in the form of a sledge are drawn to the surface, where the “fragrant” hydrogen sulfide gases are released into the air after many months of inactivity, allowing Mother Nature to do the rest.
This year, Carrier said it appears that the fluctuating climate might have led to the lower-than-average oxygen levels in the lagoon, though there’s no way to be entirely sure.
“Several weeks ago the levels dropped,” he said. “So we’ve been aerating that area to help break down the wastes faster. The lagoon is doing what it’s supposed to do, but for some reason the smell is definitely more pronounced right now.”
As of this week, oxygen levels in the lagoon have returned to normal, and town officials are hoping the air clears soon.
Carrier said the foul odors occur each year around this time, though this season has certainly been one for the record books.
“Unfortunately, the smell is making a beeline across the highway and into Londonderry and there’s not much we can do to stop it,” he said. “The good news is it’s definitely a seasonal issue, one that will hopefully pass very soon.”