The wetlands that circle the treatment complex and separate it from the airport runways and the rail tracks and river are regulated at least in part by the North Andover Conservation Commission. Hogan said Jennifer Hughes, the town’s conservation administrator, visited the plant after the spills began.
She did not return phone calls.
On Friday evening, a cleanup crew of five was slogging through the smelly black slop a few feet from a cascade of sludge pouring from one of the tanks, armed with a Squeegee, a water hose and a 2,500-gallon pumper truck they called “the sucker.” Crew member William Ferrier said he has seen several similar overflows since he began working at the plant when it opened about 38 years ago. He said the overflows — referred to in the industry, benignly, as “foaming” — are common at treatment plants with floating tops. The Lawrence tanks were installed in 2002.
“There’s nothing we’re doing wrong,” Ferrier said as he used a Squeegee to push pools of putrid water away from the wetlands and back toward the treatment tank, a task he said was ordered by the DEC engineers who visited. “It’s not unusual for a (treatment) process like this. It’s the nature of the beast.”
“This is the time of year it happens,” said Dan Roberge, another plant employee assigned to the cleanup Friday, who blamed the overflow on the recent hot weather. “We’re doing a really good job. We’re shorthanded.”
All five men on the crew wore gloves and one or two wore rubber boots, but none wore the masks, eyewear or other protective gear or clothing recommended by Gorn, the Lawrence Health Board chairman.
The Greater Lawrence Sanitary District has had a handful of other problems in recent years.
In 2006, the district paid a $254,000 fine and made upgrades costing $18 million to settle allegations by the EPA and DEC that it was releasing millions of gallons of untreated sewage annually to the Merrimack River.
More recently, on Feb. 28, a man working for an Atkinson, N.H., contractor broke several bones when he fell while making repairs inside one of the treatment tanks. The federal Occupational Safety and Health Administration issued two citations for unsafe working conditions against the contractor, Advanced Design Construction, and fined it $4,800.
The sanitary district was not cited or fined in the incident.