For years, Colonial Pipeline Co. was a silent neighbor to some residents of Fairfax County, many of whom were barely aware of the two underground steel pipes, part of a 5,000-mile interstate petroleum pipeline, buried beneath their yards.

Then Colonial announced plans to tear down every mature tree in the 50-foot-wide easement along three miles of pipeline that run south of Fairfax City from the tank farm on Pickett Road to the University Shopping Center.

Colonial said chopping down the trees was necessary to prevent roots from damaging the pipes the pipes and keeping the foliage from blocking the view of pilots conducting aerial inspections.

The three-mile segment is part of Colonial's overall plan to clear about 17 miles of right of way from the tank farm to Dulles airport.

The residents quickly discovered how little control they had over land they had landscaped and maintained as part of their yards and took the matter to Fairfax County Supervisor Sharon Bulova (D-Annandale). Last week she met with affected homeowners on a walk along the easement.

"In 10 years, {Colonial} has never expressed the necessity for the sudden interest in safety that would require cutting down trees," said Bruce Young, of Catterick Court. "I just felt as if I'd been personally violated by the attitude of the Colonial people who seemed to feel there was no compromise possible."

Young said he spent $15,000 landscaping the yard around his house, much of which belongs to Colonial. "If I had let {the easement} be in its natural unkempt state, you can imagine what {my lawn} would look like," Young said. If Colonial clears its easement, Young will lose nearly three dozen trees, leaving only one.

Young said he secured Colonial's permission before landscaping the easement. A Colonial representative last week denied that such permission was granted.

Colonial is required by federal law to keep its easements clear. But Colonial representative Gary Glancz said, "We haven't been clearing them as regularly as we should have, and that's why there are trees there."

Now, after about seven leaks in Virginia since 1973, Colonial is under pressure from the federal government to police its pipeline. "We have had leaks in other areas of the pipeline that have killed people," Glancz said. Such accidents "raised the profile and scrutiny on anyone who handles petroleum . . . . If there's any weakness in your system, now is the time to find it and repair it."

At an emotional public meeting last week attended by about 100 residents and local politicians, Colonial shot down residents' suggestions to save the trees, such as replacing aerial inspections with foot patrols or eliminating only trees nearest the pipeline.

Glancz said foot patrols are less practical than aerial inspections for finding signs of damage to the pipeline over a large land area. "It's impractical today for people to climb fences and look in other people's back yards. It's unsafe for them," said Glancz. "For a 5,000-mile system, you'd have to have a work force of thousands of people."

Although the easement is only 30 feet wide in some spots, Glancz said areas where the buffer is 50 feet wide needed to be kept completely clear of trees to allow easier access and maneuverability for heavy equipment to dig 24-foot-wide holes when making emergency repairs.

"I wish there was another alternative," Glancz said. "As we see it, it's a no-win situation. We have a choice of two things: Make a whole bunch of landowners unhappy and take down their trees, or not do anything and have an unsafe right-of-way."

Bulova is convinced that Colonial can find a more neighborly alternative to cutting down trees. "Not in a million years would I want to jeopardize public safety. But I'm not convinced there are not areas where {Colonial} can't leave some trees," she said. "I personally feel there's room for negotiation here, and I'm going to try to convince them."