A gasoline spill in Woods Cross Thursday afternoon forced about 50 families to evacuate their neighborhood after fumes backed up through drains and into homes.

A Woods Cross police spokeswoman said about 200 gallons of gasoline were "accidentally released" from a line at Crysen Refinery, 2355 S. 1100 West, at about 1:30 p.m. The spokeswoman, who declined to give her name, said the gasoline "swept away" into the sewers.Crysen plant manager Harry McSwain, however, said the 200-gallon estimate is probably high and it appears very little gasoline actually leaked into the line.

"We think now it was a very small amount. When I reported it, I had to guess and I guessed big, 200 gallons, because I didn't want more to show up later," McSwain said.

The plant manager said a line used to test the meters on the pumps in front of the refinery, where the gasoline is sold, apparently leaked. The line is only used every two or three months to test the meters, McSwain said, and may have developed a pinhole leak or frozen.

The leaking gasoline trickled into a discharge box and then into the sewer system, McSwain said.

The refinery began flushing the lines, putting up to 500 gallons of fresh water a minute into the sewer to dilute the spill, a move recommended by the health department and other hazardous materials response teams at the site.

McSwain said they then went downstream to the sewage treatment plant and waited for the gasoline to arrive.

"Hardly anything came through at the plant. It was almost instantaneous. It was just there and gone," McSwain said, causing no problems at the treatment plant.

"We waited until almost 7 p.m., but nothing more came through. That's why we think the spill was actually smaller than 200 gallons," he said.

McSwain said the ground around the leaking pipe is frozen and will be difficult to dig up, so the meter testing line won't be used until it can be repaired.

Within an hour of the spill, people living in the neighborhood north of the refinery began to call the Woods Cross police and South Davis Fire District to report the smell of gasoline in their homes.

Mountain Fuel emergency workers went into the homes and turned off natural gas pilot lights. Many of the neighborhood residents had already left their homes. Those who hadn't were evacuated, the spokeswoman said.

An emergency center was set up in a nearby church.

Emergency crews tested each home for the presence of the dangerous fumes, and as the homes tested safe, the residents were allowed to come home. By 7 p.m., all of the families were able to return, the spokeswoman said.