The gas leaked from a tank car breached in the derailment Nov. 30 and readings of it in the air persisted until the remaining vinyl chloride, which was in liquid form, was neutralized and removed Wednesday evening.
While most evacuees were allowed to return Friday, residents of 10 houses closest to the bridge cannot go home yet, officials said.
U.S. Sen. Robert Menendez (D., N.J.), visited the unified command overseeing the cleanup and said the wreck on a bridge dating from 1873 underscored the dire state of the nation's transportation infrastructure.
The bridge is owned and operated by Conrail, and Menendez said the railroad was going to find itself on the hook for costs related to derailment far beyond providing hotel rooms and assistance to those who were evacuated.
"Just as BP learned its lesson in the Gulf, Conrail is going to learn its lesson here," he said, referring to the Deepwater Horizon oil spill, which has cost BP billions, including a $4 billion fine to the federal government.
In a lawsuit filed against Conrail and its parent companies, apparently the first linked to the derailment, a Paulsboro mother of three who does not live in the evacuation zone is seeking more than $150,000 in compensation for injuries and at least $10 million in punitive damages.
Returning residents were encouraged to accept an offer to have the air quality in their houses tested by experts on hand. Any home with any readings for vinyl chloride was to be ventilated for two hours and tested again before residents would be allowed to return.
"We get to go home! We get to go home!" C.J. Jefferson, 24, chanted with a smile as he entered the Paulsboro Volunteer Fire Association to file paperwork.
Jefferson, who was evacuated Tuesday, said the last few days were "terrible" without access to his belongings. "Would you like to be blocked outside your house?" he asked.
Marie Killmer, 44, had her house checked for air quality, and the readings showed it was safe. But Killmer, who was evacuated the night of the derailment, said the last week of living in a crowded hotel with two children and three grandchildren had been "hell."
Joseph Wood, 28, who lives with his girlfriend in one of the 10 houses still under the evacuation order, said authorities were "not telling us anything" about when they could expect to return home.
He credited officials for "trying to take care of us as best they can," but said a hotel is "still not home."
Paulsboro Police Chief Chris Wachter said at least one home was burglarized during the evacuation.
Coast Guard Capt. Kathy Moore, whose agency is heading the unified command, said the coming days would be dedicated to preparing to lift two tank cars carrying vinyl chloride from their resting places in the creek.
She said divers working during daylight slack tides will inspect the water around the partially submerged cars for any possible obstacles or equipment that might damage the tanks.
"These diving operations are incredibly risky," she said, adding that removing the cars will involve a "series of scripted and coordinated events."
Moore said the cars are designed and made to be lifted and have lift points on them.
Riggers will prepare the cars to be lifted from the water by a crane, which will then place them on a barge on the other side of the bridge.
She said the risk to public health "is extremely limited" compared with what crews faced in dealing with the breached car.
Suppression equipment is in place and the evacuation order would not have been lifted if a serious threat remained, Moore said. But she raised the possibility that residents might have to stay inside their homes - shelter in place - in case of a mishap.
A website, www.paulsbororesponse.com, has been set up to keep residents informed.
The suit against Conrail and its parent companies, Norfolk southern Railway Corp. and CSX Transportation Inc., was filed by Alice Breeman in U.S. District Court in Camden on Thursday.
Breeman claims she and her three minor children suffered physical and mental injuries and the loss of current and future income because of the accident, which the suit blames on negligence by Conrail and its employees.
The suit claims that Conrail failed to properly inspect and maintain the swing bridge and that its employees negligently operated the train against a red signal, causing the derailment and chemical spill.
Michael Hotra, a Conrail spokesman, said, "We will respond to this lawsuit at an appropriate time and in an appropriate place. Our focus today is on . . . helping residents get the help that they need, and helping them return safely to their homes."
On another front, the National Transportation Safety Board said its investigators had wrapped up their initial on-scene investigation of the derailment and are expected to issue a preliminary report in two weeks.
An NTSB "go team," led by agency chair Deborah Hersman, arrived in Paulsboro hours after the wreck but was hampered in getting to the crash site until Wednesday night because of the lingering presence of vinyl chloride.
The NTSB said in a statement that its investigators had "collected hundreds of photos, videos, data, reports, and records; completed mechanical inspections of the locomotives and cars that have been removed from the accident scene; interviewed Conrail employees, witnesses and first responders; and documented the accident site."
Investigators will return later to the bridge where the train derailed for follow-up work, the agency said.
During the on-scene investigation, Hersman had said the agency was paying particular attention to the operation and condition of the swing bridge over the creek.
Contact Joseph Gambardello at 856-779-3844 or firstname.lastname@example.org