Gas prices in metro Atlanta kept rising Friday as hundreds of workers struggled to fix an Alabama pipeline leak.

Colonial Pipeline, the Alpharetta-based company that operates the pipeline, said it expects to restart the broken line next week. Excavation around the damaged area began Friday after conditions allowed for safe work, the company said.

Colonial also raised the estimated size of the spill to as much as 336,000 gallons, up from 250,000 gallons earlier.

The average price of regular gas in metro Atlanta on Friday afternoon was up 13 cents a gallon from Tuesday, according to GasBuddy, which tracks gas prices across the country. Gasoline in this region averaged $2.29 a gallon, vs. $2.16 a gallon on Tuesday, before news of the pipeline leak emerged.

Gov. Nathan Deal has declared a state of emergency, but for the "limited purpose" of suspending caps on the hours fuel truck drivers can work. The move is intended to "ensure the uninterrupted supply" of gas while the pipeline is fixed, according to the order.

The leak shut down delivery of fuel through one of the two main lines running from the refineries of the Texas Gulf Coast to Atlanta and the northeast.

It remains uncertain how long the effects of the spill on prices will last.

GasBuddy listed a Texaco in Stockbridge as the most expensive gas in the area: $2.79 a gallon.

However, a number of gas stations are still selling gasoline for less than $2 a gallon. Several stations are still at $1.89, including a RaceTrac in Milton.

While Atlanta prices escalated, national prices have barely budged.

The spill is in an isolated area south of Birmingham.

More than 500 workers were working on the Colonial pipeline, but the company had not given a cause for the leak.

The longer the outage continues, the greater the effect in Atlanta, said Laskoski.

Colonial is one of two companies operating large pipelines from Gulf refineries, and the other company has not reported a problem, Laskoski said. “But the Colonial pipeline is the primary supplier to the metro Atlanta area,” he said.

After Hurricane Katrina’s hammering of the Gulf Coast, pipelines stopped functioning and gasoline prices soared.

Two Colonial pipelines carry fuel from refineries near Houston east through Atlanta and then up the coast to New York. The second line is undamaged and Colonial says it has shifted some gasoline into that line.

“But that gas is being pumped along with diesel and jet fuel,” said Laskoski. “By definition, that has to reduce the capacity of that line for gasoline.”