On the morning of Sept. 9, an inspector with the Alabama Surface Mining Commission was performing a routine monthly check of an old coal mine in Shelby County when he noticed "a strong odor of gasoline" as well as a sheen on the surface of one of the retention ponds.

The gasoline he was smelling came from Colonial Pipeline's Line 1, an underground pipeline three feet in diameter that normally pushes 1.3 million barrels of gasoline per day from refineries in Houston to distribution centers across the Southeast and along the eastern seaboard.

That 36-inch line, built in 1963, has been estimated to supply the east coast of the United States with up to 40 percent of its gasoline supply. Colonial Pipeline initiated a shutdown of Line 1 within 20 minutes of receiving the report about a potential leak.

That section of pipeline remains closed. Eight days later, official estimates climbed to 336,000 gallons of lost gasoline. More than 700 people were working around the clock to dig up the pipe, plug the leak, clean up the old mining property south of Birmingham and restore supply.

With the flow of gasoline interrupted, the governors of six states have declared a state of emergency to allow truck drivers to work longer shifts to head off shortages at the pumps.

Gasoline is now being shipped by alternate routes throughout the southeast. Alternate pipelines are being used, and gasoline is even being shipped by tanker ship from Houston to New York.

Colonial announced Saturday the company will construct a temporary pipeline to bypass the spill site in hopes of restoring gasoline flows more quickly. No timetable was given for completing the bypass line."

Gas stations in Alabama and Tennessee have reported outages of some or all grades of gasoline, and fears of outages sparked long lines at the pump in Nashville and other locations.

A Minit Man Shell station in West Huntsville had already run out of the least expensive gasoline by Thursday afternoon. And shortages were spreading in North Alabama.

A Raceway gas station on South Broad Street in Scottsboro ran out of gas around 2 p.m. on Friday, and the Wavaho gas station in Lacey's Springs in Morgan County ran out of gas around 6 p.m. Prices have begun creeping up throughout the region, although Alabama law limits how much gas stations can increase prices during declared states of emergency.

And Gov. Robert Bentley earlier this week had already issued a warning against price gouging. He warned on Thursday "it is unlawful for any person within the State of Alabama to impose unconscionable prices for the sale of any commodity during the period of a declared State of Emergency."

Hub and spoke system

Colonial Pipeline spokesman Bill Berry said it is hard for the company to get a clear picture of the supply chain since it only distributes petroleum products for its customers and does not own the fuel. The company does not know how much its customers have in reserve or whether they can access alternate sources to keep gas pumps operating.

Because of the footprint of its distribution system, Berry said Colonial expects the worst of the gasoline shortages to be felt in Tennessee, Georgia, parts of Alabama and the Carolinas.

Colonial operates two parallel pipelines through Alabama: Line 1, normally used for gasoline; and Line 2, normally used for distillate products like diesel fuel, jet fuel, and home heating oil.

Both lines are operating in west Alabama, meaning that part of the state could have easier access to gasoline than places north and east of the leak. Line 1 is taking limited shipments of gasoline from Houston to west Alabama, but stopping before the leak site in Shelby County.

Line 2 is now alternating between its usual distillate products and regular gasoline from Houston to Atlanta. Colonial would not say how much gasoline is making it through the detour system to points in Atlanta and beyond.

From Atlanta, Colonial operates seven "stublines," or shorter pipelines that transport gasoline to places like south Georgia, Nashville and Knoxville. Those appear to be areas experiencing the most outages.

The dig begins

Crews began excavating the leaking pipeline at around 3:30 p.m. on Friday, but the cause and status of the leak is still unknown.

Colonial Pipeline and U.S. Environmental Protection Agency personnel on the scene say most of the gasoline from the spill is believed to be contained in a mining retention pond and does not pose a risk to the nearby Cahaba River or to local residents in nearby towns, including Helena and Alabaster.

For more than three days after the leak was discovered, pipeline workers were unable to access the site due to high levels of hazardous benzene and gasoline vapors that exceeded safe working conditions standards set by the U.S. Occupational Safety and Health Administration.

Crews finally received clearance on Tuesday to begin removing gasoline and water from the retention ponds and transporting it back to Colonial's Pelham tank farm facility for treatment.

Local authorities, including the Pelham Fire Department, continue to monitor air quality conditions at the site to protect response workers. Pelham Fire Chief Danny Ray said the vapors do not constitute a threat to nearby residents, with the nearest dwelling about 2.5 miles away.

Temporary blockages were installed on either side of the leaking section on Thursday, and crews began siphoning gasoline from the leaking pipeline itself.

According to a preliminary report released by federal regulators from the Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA), the suspected leak site is about 460 feet south of the pond.

PHMSA will have to approve the restart of the pipeline and has personnel on scene to investigate the cause of the leak. Also on the scene are representatives from the U.S. Environmental Protection Agency, which is enforcing the Clean Water Act, and the Alabama Department of Environmental Management, which will supervise the remediation of the site after the leak is stopped.

Environmental catastrophe likely averted

If the leak had developed in a slightly different location, the concern for Alabamians may have nothing to do with long lines at the pump.

The leak is located in the William R. Ireland Sr. Cahaba River Wildlife Management Area, near the intersection of Coalmont Road and Lindsey Road. It's a relatively remote section of Shelby County, about 30 miles south of Birmingham.

The Cahaba River is home to 135 known species of fish, according to the Alabama Department of Conservation and Natural Resources, as well as 35 snail species, 10 of which are not found anywhere else in the world. Ten species of fish and freshwater mussel in the Cahaba are listed as threatened or endangered under the Endangered Species Act.

A few miles downstream from the leak location lies the Cahaba River National Wildlife Refuge, which is known nationally as a viewing spot for the Cahaba Lily in the spring. A major drinking water intake for the Birmingham Water Works is upstream.

"It's really pretty fortunate where it is," said Cahaba Riverkeeper David Butler, who has been actively working with Colonial and government agencies during the spill response. "It's in pretty contained area, and it's been so dry here that most of the little perennial streams are pretty dry right now so there's not really a lot of potential at this point for it to migrate towards the river."

Cahaba Riverkeeper is a clean water advocacy group that is part of the larger Waterkeeper Alliance, whose members frequently file law suits against large corporations who are involved in spills.

The Riverkeepers are often left out of emergency response situations and treated as adversaries by the companies involved, but Butler said that has not been the case in this incident.

"They've been very open in terms of keeping us updated and allowing us access and taking suggestions and all those sorts of things," Butler said. "In terms of protecting the river, they certainly seem genuine in their desire to do as much as they can to prevent it from reaching the river."

Butler worked with Colonial employees to point out potential sources of infiltration, and where to monitor to ensure that gasoline does not reach stream beds that could carry it to the Cahaba. It's a level of cooperation he's not used to.

"I keep shaking my head and thinking 'Am I still in Alabama?'" Butler said. "It's certainly unusual in this type of situation to have that kind of cooperation."

Some residents concerned

Despite the assurances of Colonial Pipeline and state and local officials, people living near the site of the spill are concerned about possible impacts to their drinking water, or to wildlife in the Cahaba.

Billy McDanal lives less than 500 yards from the edge of the Wildlife Management Area in the small community of Maylene. He and his son have hunted, hiked and ridden four-wheelers throughout the management area and its surroundings for over a decade.

McDanal says he is nervous leaked gas could enter the water table and end up in his basement, where water often collects when it rains.

"What's got me worried with the gas is that it's going to go ... underneath my house and am I going to get gas coming under my house?" he said.

Colonial began distributing fliers to local residents explaining that residents can expect to see more trucks and equipment than usual on County Road 91 (Coalmont Road), and that there might be "higher than normal" noise levels due to clean-up and repair operations.

The flier goes on to say: "There are no public safety concerns at this time and the situation has been contained to the strip mining area where the release occurred."

AL.com reporters Connor Sheets, Leada Gore and Jonece Starr Dunigan contributed to this report.