Fears of an explosion emptied homes, shuttered stores and closed busy roads yesterday after 4,000 gallons of gasoline spilled underground at an Amoco station near a bustling intersection east of Towson.

Roads around Loch Raven Boulevard and Taylor Avenue were cordoned off until late afternoon, and dozens of residents were evacuated to a nearby high school while firefighters flushed miles of storm drains to clear the vapors. Businesses in three of the intersection's shopping centers closed for much of the day.

"There was a high concentration of gas fumes," said Battalion Chief Pat Kelly of the Baltimore County Fire Department, adding that explosion of vapors was the greatest danger posed by the spill. "You get enough fumes in a confined area for long enough, you've got a possibility of that."

It was not clear why the gas leak went undetected until thousands of gallons had spilled, but state officials said an alarm system designed to send an early warning had failed.

"There was a problem with the alarm," said Alan Williams, chief of the emergency response division of the Maryland Department of the Environment. "One drop of gas out of that tank and the alarm is supposed to sound. It didn't."

Amoco officials, investigating the leak, said they did not know whether the alarm worked.

Slightly more than half of the spilled gasoline was caught in a graveled underground containment area beneath the station, where environmental workers vacuumed it out. By late yesterday afternoon, about 900 gallons of the 4,000-gallon spill remained .. unaccounted for, according to Maryland Department of the Environment spokesman Quentin W. Banks.

He said much of the 900 gallons apparently contaminated the soil near the spill site. MDE workers said about 30 gallons flowed through drains and sewers into nearby Herring Run, where cleanup workers blocked it off and mopped it up.

No one was hurt and environmental damage appeared minimal. The risk and inconvenience to residents were another matter.

"Location, location, location," said the MDE's Williams with a sigh as he directed cleanup workers. "This affected three shopping centers and an apartment building."

One store, Greetings & Readings, reopened at 5 p.m.

"But it killed the day," said Steve Baum, the store's president. "It was a major loss for the day. I know it will be many, many thousands of dollars."

Chris Rogers, director of the Super Fresh in Loch Raven Plaza, said employees were preparing to open yesterday morning when they heard the news.

"The Fire Department told us to get out, and we left, no questions asked," he said.

Area resident Ayesha Majeed was one of those evacuated from a section of the Glenmont Apartments on Lachlan Circle, downhill from the Amoco station.

"The police officer came and said to take my belongings and come out," she said as she cradled 14-month-old Amara and kept a watchful eye on 2-year-old Amry and 7-year-old Aqmal, who romped on the sidewalk yesterday afternoon.

She and her children went to a friend's house in a nearby apartment complex. But others had to go to a temporary shelter set up at Loch Raven High School, where the Red Cross fed 57 evacuees and nearly as many fire, police and rescue workers.

"When they said we had to evacuate, I just got my medication and my important stuff and I was out of there," said Glenmont resident and evacuee Mary Brown, 70, who spent several hours at the high school.

The spill affected even those away from home. Rose Tatum and Lizzie Gathoga, both Glenmont apartment residents, were out of their homes yesterday morning when the roads were blocked off -- Tatum dropping her children off at day care and Gathoga at work. Neither was allowed back in until about 2 p.m.

Motorists who tried to turn onto Loch Raven Boulevard, which was closed from Taylor Avenue to Northern Parkway, were routed to York Road or Perring Parkway. Loch Raven Boulevard and Hillen Road were closed, police said, but no residential or commercial areas in the city were evacuated. However, buses were parked along Loch Raven Boulevard, ready to evacuate residents if necessary.

Tiauna E. Flournoy, 23, and Tamarac C. Harding, 21, tried to drive from their home on Limit Avenue, but were puzzled by the closure of many local streets.

"I though they were doing a TV show -- an episode of 'Homicide,' " Flournoy said.

State and local officials said the gasoline leak apparently began Tuesday afternoon at the Amoco station which, according to Amoco spokesman Gary Shute, is franchised to Emmitt Knight and opened three months ago.

Shute said a metal fitting on a vinyl hose connecting the underground tank with the above-ground pump split, and gas began leaking through the hose.

The leak triggered an alarm warning that the tank was getting low on fuel so station employees called Amoco and 3,500 gallons of gasoline were pumped into the tank that afternoon, Shute said.

But later Tuesday evening, attendant Gwen Nwosu noticed that the regular-grade gas pump wasn't working properly and began tests to find the problem, Shute said. By midnight, Nwosu had notified officials at Amoco that gas was leaking. Amoco alerted local and state officials.

"They told us they had an underground problem -- 4,500 gallons of gas they couldn't account for," said Banks, the MDE spokesman.

By late yesterday, the amount of gasoline spilled had been revised to 4,000 gallons, with 3,100 gallons accounted for, he said.

"The best indication we have is that there was a failure in the lines from the underground tank to the dispenser," Shute said. "Why it failed, we don't know. Everything is brand new except the tanks, and that's not where the leak occurred."

Leaks from underground storage tanks are the most common source of groundwater contamination, and gasoline is the most frequently reported contaminant, according to the Environmental Protection Agency. There are 1 million tanks in the United States and, according to EPA figures, 332,000 of them have leaked at least once in the past nine years.

In Maryland last year, 13,066 leaks occurred, most of them small. MDE officials described yesterday's spill as one of the larger ones this year but said environmental damage did not appear significant.

"To be perfectly honest, I'm not sure you could hurt that stream -- Herring Run is a hurting little stream," said Williams, MDE's emergency response chief. "It runs through Baltimore City and takes on a lot of pollution."

There were no signs of a fish kill, Banks said. However, the spill could cause delayed harm to animals that can cope with the stream's normal overdose of pollutants.

But a cleanup worker said yesterday that gasoline is light and evaporates quickly.

"I assure you that when we're done, the environment will be back to normal," said Keith Beck, general manager of A & A Environmental Services, which is handling the cleanup for Amoco.

To protect Herring Run, the company installed metal mesh fences in area storm sewers, each covered with a polyurethane pad that absorbed gasoline while allowing water to flow through, Beck said. No one could estimate the costs of yesterday's cleanup, but Banks said state law mandates that the costs be paid by the polluter.

The spill brought dozens of police and firefighters to the scene for much of the day, as well as representatives from the Coast zTC Guard, which has jurisdiction over Herring Run, and public and private environmental workers.

Accident reports from the Coast Guard, the Maryland Department of the Environment and other agencies go to the EPA's regional office in Philadelphia, where they are reviewed for potential violations of federal pollution laws such as the Clean Water Act and the rules that govern underground storage tanks, said EPA spokeswoman Bonnie Smith.

Local officials said they expect traces of the gasoline to linger at least a decade.

"We'll be getting calls up here every time it rains from now on," said Kelly, the battalion chief, as he watched workers pumping gasoline and water from under the Amoco station.

"It doesn't go away," agreed firefighter J. J. Fannon. "It never goes away."

Pub Date: 6/25/98