SAN DIEGO -- They're being called rolling bombs: trucks carrying combustible, pressurized gas. Some residents are concerned that trucks hauling methane are scheduled to be driven through a busy part of San Diego.

Methane is a major bi-product of waste water treatment and the City of San Diego has a lot of it. Leaders call the solution to get rid of it "green," but others say it could be deadly.

The city clearly knows the dangers of methane gas. They have a warning sign posted about it on the front gate of the waste water facility.

But potential dangers, including explosion and asphyxiation, haven't detoured a private company called Biofuel Energy. It's agreed to get rid of the city's methane.

They'll transport it on a 45-foot, 38-ton flatbed filled with more than 183,000 cubic feet of compressed methane gas.

The proposed route is on Catalina Boulevard. The trucks would rumble past the homes there with the equivalent of about 4,000 pounds of TNT.

Eventually they'll repackage the methane and sell it as a power source. Of course, Biofuel Energy will keep most of the profits. Homeowners aren't happy.

"All you need is a single accident to develop into a catastrophe itself," one resident told 10News.

"I saw that we're taking on all the risk and somebody else is getting all the reward," homeowner John Pedersen said.

We found the risk won't fall to the city. According to the contract, Biofuel Energy assumes all risk of transportation. And they're prepared for it, insured for the worst-case scenario - a $5 million policy every time something goes wrong.

"The elected officials that we have in office have a responsibility to make sure we're safe. That's one of their prime responsibilities and in this particular case I felt that the elected officials let us down," said Pedersen.

The city council voted unanimously to approve the methane transport project. Now more than 300 residents have signed a petition to stop the trucks.

"This one doesn't bother me at all and I applaud the city," chemical expert Dr. Neal Langerman said. Langerman knows a lot about methane and said the city's solution is a good one and a green one.

But experts have also said that in a worst-case scenario the truck's contents could explode with a blast radius of up to a mile.

"An event, an explosion of some sort that includes the tube trailer... that will be ugly," Langerman said.

What's more likely, they say, is that a tank ruptures and its safety system vents the gas. Since methane is lighter than air, the gas and the danger simply float away.

10News called councilmember Kevin Faulconer, who represents Point Loma. He agreed to meet on Friday with the concerned neighbors who spoke with us.