Despite that link, city and railroad officials said it was too soon to conclude that the 1,000 gallons of tripropylene that mysteriously appeared in Inner Harbor sewers came from the train, in part because the city’s sewer system is extremely old, complex and, in some cases, poorly mapped.
“It looks like a maze,” Michael Sharon, chief of the Maryland Department of the Environment’s emergency response division.
“The city is 200 years old, and there’s a whole network of tunnels down there,” he said. “It’s not uncommon to find tunnels that don’t show on maps. … So many things occurred under these streets. It’s very complex, and there are things out there sometimes that people don’t expect.”
Using tools as simple as fishing rods and as powerful as 2 million gallons of gushing water, Baltimore emergency workers worked through the night Saturday to remove all but the faintest whiff of the chemical by yesterday morning.
Downtown streets reopened to traffic by late yesterday morning, and officials expected to have three traffic signals that were darkened by the blasts working for today’s morning rush hour.
The main task ahead is detective work, as officials try to determine what caused three 300-pound manhole covers near the intersection of Pratt and Light streets to shoot up to four feet in the air about 5:15 a.m. Saturday.
No one was injured, and officials said the chemical did no environmental harm to the Inner Harbor. A boom and absorbent pads contained and collected any tripropylene that flowed into the water.
City Public Works Director George L. Winfield said it is not clear how the tripropylene ignited or how it wound up in the sewers in the first place.
On Saturday, Public Works Department spokesman Robert Murrow said the train tunnel’s drainage system was separate from the city’s sewer system. But yesterday, Murrow said CSX officials had informed the city of a connection.
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“There is a link from the tunnel to the storm drain,” Murrow said. “CSX told us.”
Robert L. Gould, a CSX spokesman, said the tunnel’s drainage system connects to the sewers about 600 feet to 700 feet south of the intersection of Lombard and Howard streets.
“We and the state had tested [the connection area] during the [train] incident and yesterday tested again to see if there was a presence of that product, and none was noted,” Gould said. “Obviously, we’re going to continue to cooperate to try to get to the source of it.
“Obviously that’s one logical source that officials would be looking at, but as expansive as the city sewer system is and as common as the chemical is, it’s extremely premature to jump to any conclusions,” Gould said.
“You do have industry in the area that uses this chemical” for the manufacture of plastics and petroleum products, added Gould, who said he did not know the companies by name.
Some forms of the chemical have a flash point as low as 75 degrees, meaning its vapor can explode when exposed to flame at that temperature, Baltimore Fire Department spokesman Michael M. Maybin said.
Winfield said it is possible that Baltimore Gas and Electric Co. electrical lines running through the sewer could have caused a spark, but he said that had not been determined.
“We’re going to take a look to see if our equipment could have been involved,” said Karl Neddenien, a spokesman for BGE.
Winfield also said it was possible that recent rains played a role, because the water washes through storm drains. On Friday, Baltimore received 0.64 inches of rain, which at that point was most substantial single rainfall since the train accident.
Baltimore firefighters, along with workers from MDE and the city’s public works department, pried open 30 to 40 manholes looking for the chemical. Using ordinary fishing rods supplied by MDE, they dangled specialized sponges that will not soak up water but will sop up chemicals such as tripropylene, Sharon said.
The sponges turned up soggy in about five spots, all centered at Pratt and Light streets, he said. Winfield described that area as “the [geographic] low point in the storm drain system.”
Workers used pumper trucks to draw off 1,000 gallons of the chemical, which floats on water. They also pumped out more than 10,000 gallons of contaminated sewer water, public works spokesman Murrow said.
Then, early yesterday morning, when there were few Baltimoreans awake to complain about low water pressure, workers flushed out the sewers by opening 48 fire hydrants for an hour to 90 minutes, Sharon said. Each one gushed 750 gallons a minute, creating a 2-million-gallon flood that drowned city streets in several inches of water before washing into the sewers. The boom and absorbent pads trapped traces of tripropylene as water washed into the harbor, Coast Guard Cmdr. Quain Kahler said.
Officials said their investigation could take weeks or longer.
Sharon said officials will pore over maps of the city sewer lines, tracing all of the connections. They will also inject a harmless fluorescent dye into parts of the system to trace its flow.
“We’re going to do a painstaking analysis,” Sharon said. “It’s a little like detective work.”
Regardless of whether the train and manhole accidents turn out to be connected, Inner Harbor visitors will probably recall the strange disruptions both caused in the hub of the city’s tourist district.
“I’m starting to get a little nervous about Baltimore,” joked Rick Kennedy, 50, who had traveled from Milton, Mass., to see the Red Sox play the Orioles.
Kennedy and his 14-year-old son, who were staying at a downtown hotel, were taking the police tape and detours in stride.
Even Winfield, who emphasized that there was no known link between the train derailment and exploding manhole covers, said the two incidents have him bracing for the next emergency.
“It’s gotten to the point now where I just wait for the next event,” he said.