For the Subaitani family, the choice came to this: Pay tens of thousands of dollars to replace the aging underground storage tanks at their Brentwood gas station or risk stiff fines from the federal government. It didn't turn out to be much of a choice at all. After eight years of pumping gas at their small station on Bladensburg Road, Cathy Subaitani and her husband, Fahed, closed their business for good on Dec. 19, joining hundreds of mom-and-pop station owners here and across the country who say they were forced out of business by the new environmental regulations. "We have no idea what we're going to do," Cathy Subaitani said one recent evening as she and her husband cleaned out the station. "Especially at Christmas time, I think it's really crummy. It's a disaster." The Subaitanis closed their station three days before the Environmental Protection Agency's Dec. 22 deadline for replacing or upgrading old underground storage tanks that hold gasoline or other fuels. The EPA rules were approved a decade ago but were not enforced until now to give station owners time to improve or replace their tanks. The Subaitanis, however, said they were not told of the coming regulations when they bought their station eight years ago and didn't learn of the new rules until four years later. They wanted to upgrade their tanks, but EPA officials told them that they needed new tanks to meet the regulations. And so, with some bitterness, the Subaitanis are getting out of the business.

The EPA rules are the result of increasing concern that gas station tanks across the nation are leaking fuel and contaminating ground water. The cost of replacing three tanks -- which is how many a typical station has -- can be as much as $150,000. Federal officials said that there have been about 360,000 documented underground tank leaks nationwide and that half of those have contaminated ground water. The regulations require the use of tanks that are more durable and less susceptible to leaks and have overflow areas to handle any spills. Large corporations such as Mobil, Exxon and Shell have upgraded thousands of tanks nationwide over the last several years, but many small, independent gas station owners have struggled to comply with the regulations. Faced with expensive replacements or fines of up to $11,000 a day, some, like the Subaitanis, are closing shop, unable to come up with the cash to make the changes. Nationwide, the EPA estimates that 40 percent of the approximately 1 million underground storage tanks in use are in violation of the new standards. In Virginia, officials say, about one-third of the state's 18,000 tanks are in violation; about 15 percent of Maryland's approximately 18,000 tanks have not been upgraded or replaced. Although many states have instituted programs to help station owners improve or replace their tanks, the financial strain on small service stations has been great. For example, Maryland has provided more than $5 million in low-interest loans to operators and helped to fund leak cleanups, but some businesses still haven't been able to stay afloat. Virginia and Maryland officials haven't kept track of how many service stations have had to close or scale back because of the regulations, but said those in rural areas have been hardest hit. "In the metropolitan area, if you have a good corner location, you can make it," said Herb Meade, chief of compliance for the Maryland Department of the Environment's oil control program. "The ones we're seeing going out of business are those in Western Maryland or on the Eastern Shore." Since the regulation was developed in 1988, Meade said, the number of tanks in Maryland has dropped from 40,000 to about 18,000. Federal officials have said they are going to give small operators and local and state governments a break in enforcing the new rules, initially concentrating enforcement on sites with multiple tanks and on environmentally sensitive areas such as those near lakes or wetlands. But the reprieve is only temporary, and many owners are rushing to upgrade their tanks. "The EPA recognized that this might be a financial burden and gave people 10 years to comply," said Ruth Podems, an EPA spokeswoman. "Now the deadline has come, and we're going to start enforcing. We're not backing off on the mom-and-pops. We're just looking at the big guys first." For CBM Construction Co., of Fredericksburg, Va., the tank replacement operation has more than doubled in just the last six months. Some of the company's clients, such as a Crown gas station on Centreville Road in Manassas, got a late start and now sit vacant as construction crews tear through the cement and carve space for 10,000-gallon tanks out of the ground. A CBM spokesman said much of the construction has been in Northern Virginia. The work is underway at several large oil company locations as well as smaller independent stations, some of which will be closed for more than a month. Several industry groups have been pushing the EPA to be equally tough on all violators, saying that any forgiveness in enforcement is unfair to station owners who have suffered financial hardships in order to comply with the rules, said Roy Littlefield, executive director of the Lanham-based Service Station Dealers of America. "Those people who took the EPA seriously had to close down for weeks to upgrade," Littlefield said. "It's unfair that some people had a setback and their competition didn't, and they aren't having it held against them. "It wasn't a rule that we were all excited about, but we {lobbied} to make it easier for the small guy by giving a 10-year lean-in period," he said. The owners of Propp's Grocery on Route 234 in Prince William County replaced the three tanks at their gas station less than three years ago, and they said the disruption nearly toppled the small business. Shelling out more than $120,000, the Shumate family had to close down the most lucrative part of their business for five weeks to have "three perfectly fine tanks ripped out of the ground," said Tony Shumate, 34, who manages the store his mother and father have owned since 1985. Shumate said the family had to take out a small-business loan to pay for the replacement, adding that the 90,000 gallons of gas the store sells each month account for more than half the store's profits. "It devastated us at the time," he said. "If we hadn't been really successful for the 10 years before we did it, there is no way that we would have made it through. I can see how this could shut a lot of mom-and-pops down." CAPTION: Fahed Subaitani stands in front of the Brentwood gas station, which was closed because environmental regulations requiring new tanks were too costly. ec