How Long Has Baltimore Had Steam Pipelines?

BALTIMORE (WJZ)-- Miles of steam pipes are still working beneath Baltimore streets as investigators try to pinpoint what caused one section of the 30-year-old system to explode Tuesday afternoon.

RELATED: Steam Explosion Under Investigation In Baltimore City

Beneath Baltimore's busy streets lies a hidden labyrinth of pipes that pushes steam and hot water to the City's office buildings.

It's a complex process that meets basic needs of the City.

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"A lot of systems can use the water for their laundry or heating needs," said energy efficiency expert Anne Hampson.

Hampson said it all starts inside plants, like the ones owned by the company Veolia.

The pipes, which are scattered around downtown Baltimore and Harbor East, burn household trash and heat water. The steam can be as hot as 200 degrees Celsius.

"In steam terms, that's not that hot," Hampson said.

The 30-year-old system was a mystery to many in the City. That all changed Tuesday.

A similar incident happened last month in St. Louis and in 2007, when a massive and deadly explosion rocked Manhattan.

Veolia isn't saying if the incident can happen again.

Hampson said this is a rare occurrence. The risks of steam pipe systems are low and the benefits are  high.

"While accidents can happen, I would hate for there to be a negative stigma on these systems because they are so beneficial," she said.

The company's website said about half of the steam that goes to customers is recycled, making it a green type of energy.

Veolia has similar underground pipelines in other major east coast cities, including Philadelphia and Boston.