Compared to NJ Transit's contractor toppling a 550-ton bridge into the Rancocas Creek, hacking away at some shrubbery might seem like a small slip.

But the mayor and some residents of this borough are incensed nonetheless at the way workers building the South Jersey light rail line last week lopped off about a quarter- mile of forsythias and yews bushes that had stretched from Palmyra through Riverton.

An NJ Transit spokesman said the workers were trying to make room for machinery that was needed to dig a 2-foot- wide by 2-foot-deep ditch.

"We take pride in those bushes," said Palmyra Mayor Bob Leather. "They promised us they wouldn't be touched."

But the sound coming from the future site of the South Jersey light rail line on Friday morning wasn't what some local residents along Broad Street expected. Instead of the clang of metal spikes being driven into railroad ties, they heard the buzz of power saws.

"I looked out my kitchen window and saw men carrying what looked like roots and putting them into a shredder," said Phyllis Blackeby, who lives in the 600 block of Highland Avenue.

NJ Transit spokesman Charles Ingoglia said the transit agency ordered a halt to the "pruning" as soon as it heard about it.

By that time, however, its contractor, Bechtel, or one of Bechtel's subcontractors, had trimmed the long green line of bushes along Broad Street almost to Riverton. The bushes were planted in the early 1970s by Palmyra and Riverton residents as a barrier between the track and homes backing to the rail line.

Ingoglia said the workers wanted to dig a trench for a duct that would hold wiring.

"We've asked them to look at alternate ways to solve the problem," said Ingoglia, such as tying the branches back.

"They may have to go back to pruning, but for now it's stopped," he said, adding that "we're not happy that we had to be told about this by the mayor."

Mayor Leather said he was first told that the cutting was necessary "for safety reasons," but that the distance quoted kept changing, from eight to 12 to 15 feet from the rail line.

"My impression of NJ Transit," the mayor said, "is they'll tell you anything to get you off their backs."

A spokesman for Bechtel did not respond to telephone calls Wednesday, but according to Leather and Blackeby, the company has promised to replace any bushes that die.