A Pepco tree-trimming crew works in North Bethesda in December 2010, to clear branches overhanging lines. (Susan Biddle/FOR THE WASHINGTON POST)

For many Pepco customers, the stress relief that came with a comparatively mild winter has been replaced by consternation about trees.

In the past year, the area’s largest power company has devoted unprecedented resources to trimming and removing the kinds of trees that have compromised power lines during major storms in recent years.

But those efforts have been controversial, lauded by some residents as long overdue and loathed by others who fear the loss of natural beauty and damage to the environment.

Government leaders in Montgomery and Prince George’s counties and the District said in interviews that their constituents are largely pleased Pepco is working on improving reliability. But some residents remain concerned about how aggressively Pepco is pruning, trimming and removing mature trees near their homes.

“They set it up as a choice: power or trees?” said Darian Un­ger, a Silver Spring resident whose neighborhood has lost multiple trees at the hands of Pepco contractors in recent weeks. “But it’s a false choice.”

Interviews with elected officials in all three jurisdictions show that the volume of resident complaints has been lower in Prince George’s and the District, where Pepco contractors have done less pruning than in Montgomery.

Pepco declined to reveal the exact number of trees the company has removed in the past year.

“They fell way behind on tree trimming, and it wasn’t going to be pretty when they tried to catch up,” said Montgomery County Council member Hans Riemer (D-At Large), who lives on a block where Pepco has trimmed and removed trees. “Not only that, but they’re trying to trim now to a point where it would last longer. So I wasn’t expecting that it would be pretty, but at the same time I have heard concerns from arborists that it’s been sloppy at times or excessive.”

Pepco reports that its contractors have pruned and, in some cases, cut down trees along more than 3,400 miles of power lines in Montgomery, Prince George’s and the District since December 2010.

The intent of all the trimming and cutting, Pepco officials say, is improved reliability.

“We take very seriously our responsibilities for environmental stewardship,” said Jerry Pasternak, Pepco’s vice president of government affairs in Maryland. “We also realize that there has to be a balance between vegetation management and the environment and natural landscape.

“In the end, our primary responsibility is to provide safe and reliable electric service to our customers, and while we strive to maintain that balance, if we are faced with that choice, we have to provide safe and reliable service. That is our mandate, that is our obligation, and that’s what people expect from us.”

Pepco’s tree trimming represents a concerted effort to bolster its image after a two-year period during which the company felt a backlash because of insufficient service to its 778,000 customers. A Washington Post analysis in 2010 found that Pepco ranked as one of the worst utility companies in the nation when it came to keeping the power on and restoring it after it went out.

By this past winter, Pepco had initiated a five-year, multimillion-dollar plan to correct its reliability problems. In 2011, the company increased its annual spending on tree trimming along distribution lines by $19 million from two years earlier, according to Pepco data.

“If I were Pepco, I would feel I was being criticized no matter what I did,” Montgomery County Council member George L. Leventhal (D-At Large) said. “When the wind starts to blow and the trees tumble, they get complaints about outages. And now they’re trying to remove at-risk trees, and they’re getting complaints about that as well.”

Pepco customer Margie Gustafson’s main complaint is that she had no advance notice that a tree in her Bethesda front yard would be trimmed as drastically as it was. In August, Gustafson returned from a trip to visit family in Oregon and found that the 40-foot red cedar on the edge of her property — which she has owned for more than three decades — had been shaved to its spine on one side.

Without Gustafson’s knowledge, Pepco contractors pruned the side of the tree nearest the power line — roughly 10 feet away — until it was so lopsided it appeared to be toppling in the opposite direction. A Pepco forester acknowledged to Gustafson — in person and in an e-mail — that contractors had been too aggressive in their pruning. But by then, there wasn’t much anyone could do.

“If they want to prune trees that are on your property but where the branches are next to the wires, they can do it without your permission,” Gustafson said. “That’s what they did. But they did it very radically.”

Dan Landry, Pepco’s senior staff forester for vegetation maintenance, said the company secures written permission from homeowners before removing trees from private property. When it comes to pruning on private property, Landry said Pepco attempts to give advance notice of its intentions. But if the company receives no response after a “reasonable” amount of time, Pepco contractors proceed with the trimming, Landry said.

According to Montgomery arborist Brett Linkletter, it’s not always as simple as measuring to a certain spot on a branch and making a cut. Industry standards mandate that trees be pruned to the nearest branch union, which is often closer to a tree’s trunk than the minimum cut mark.

Linkletter, who is also Montgomery’s head of tree maintenance, said he and his staff inspect each tree in a public right of way that Pepco wants to cut down. He estimated that in the past year, Pepco has asked to cut down 2,500 trees. The county has granted permission about 80 percent of the time, he said.

But Linkletter, too, might soon be inserted into squabbles over tree cutting on private property. Two Montgomery council members introduced legislation last month that would require the county’s chief of tree maintenance to intervene when a utility company cannot gain consent from a homeowner to remove a tree the utility says is an imminent hazard to its system.

Linkletter declined to comment on the proposed legislation, which is scheduled for discussion at a public hearing June 12.

The legislation also calls for utility companies to gain homeowner or occupant consent before any vegetation management is performed and would require companies to grind the stumps of trees they remove and to fill the holes left behind.

Pepco said it is the county’s responsibility to remove tree stumps. But Montgomery does not budget for that.

Leventhal said Pepco officials have told him they do not think the county has legal standing to demand anything of a utility company. According to Leventhal, Pepco officials say the company must conform only to the mandates of the Maryland Public Service Commission.

Pasternak, the Pepco vice president, said the company would make no public comment on the proposed legislation.

Roger Berliner (D-Potomac-Bethesda), chairman of the Montgomery council’s Transportation, Infrastructure, Energy and Environment Committee, said he co-wrote the legislation with council member Marc Elrich (D-At Large) because “we get complaints every day with respect to private property owners’ interaction with Pepco in which they feel totally intimidated by Pepco and basically believe they have no rights whatsoever.”

Berliner said the legislation is intended to complement regulations the Public Service Commission adopted last month. Those regulations impose more stringent reliability standards for electric companies operating in Maryland and require them to obtain permission from homeowners before pruning on private property.

The regulations also require companies to document when homeowners deny permission for vegetation management. Maryland’s new regulations — which go into effect May 28 — will not hold electric companies responsible for stump removal on public property.

Public Service Commission Chairman Douglas R.M. Nazarian said last week that he is displeased with the Montgomery legislation because he thinks it would undo the commission’s efforts to gain uniformity in governing the electric companies in the state.

“We don’t want to have a situation where the companies end up having to deal with parallel sets of legislation and regulation that could muddy up or confuse or unduly complicate or create uncertainty around their responsibilities,” Nazarian said. “We feel like we’ve made it very clear what we expect of them.”