A majestic Siberian elm towers over the entrance to the Pleasant Hill Cohousing community tucked at the end of Lisa Lane.
The elm is one tree among a dense swath of mature oaks, redwoods, walnuts and shrubs separating the 32-unit development from the bustling Iron Horse Trail.
To the residents, this lush greenery is more than just beautiful, it's functional -- providing privacy from passers-by, cooling shade in the summer and a buffer from the noise and exhaust caused by traffic on nearby Monument Boulevard.
And that could all be lost.
Cutting down these trees is part of Pacific Gas and Electric's plan to remove vegetation and structures that block access to its vast network of natural gas pipelines.
"It's everything," said Susan Fuller, who has lived in her two-bedroom unit for five years. "We would be naked here."
The tree-cutting plan has angered residents and city leaders across the East Bay who say the utility has no right to unilaterally chop down trees without permits.
After the public outcry, PG&E backed off and agreed not to cut down trees on public property or any protected trees on private property until it reaches agreements with the cities.
But some cities aren't taking the utility at its word -- they're preparing to file lawsuits if PG&E revs up the chain saws.
It's unclear how this standoff will end.
PG&E insists the trees must go and remains unwilling to comply, so far, with local tree protection ordinances.
City leaders also refuse to bend, arguing the company hasn't demonstrated the need to chop down thousands of trees.
"Safety is number one," said Martinez Mayor Rob Schroder. "But this is kind of a slash-and-burn, scorched-earth kind of policy here and it's overreaching."
The $500 million Pipeline Pathways project is a statewide initiative to clear obstructions from the utility company's 6,750 miles of underground gas lines from Bakersfield to Eureka. PG&E says it needs to remove the trees, shrubs and structures on private and public property to ensure pipeline safety -- a top priority after the 2010 San Bruno gas pipeline explosion that killed eight people and destroyed 38 homes.
Rules vary from city to city, but permits -- and sometimes public hearings -- typically are required to remove trees from private property, often depending on their size and species.
Some speculate PG&E may balk at getting permits for fear of triggering a costly and time-consuming environmental review under the California Environmental Quality Act.
"The permitting process is different in each city. We are working with each city to understand what information they need from us prior to any removals taking place," PG&E spokeswoman Debbie Felix said.
But the utility still has not committed to following tree protection laws.
Martinez, along with Walnut Creek, Concord, Lafayette, Danville, Pleasant Hill, Clayton, Dublin, Livermore, El Cerrito, Lafayette and Brentwood have all expressed concern with PG&E's plan.
And since the rollout of Pipeline Pathways began in Contra Costa County earlier this year, PG&E seems to have changed its message about the reason for the project.
When the utility described the project to the Concord City Council in February, representatives said 730 trees in the city must be removed to improve access to the pipes.
Not mentioned in that presentation -- or in notification letters it has sent residents in several cities -- was PG&E's contention that tree roots can damage the protective coating around the gas pipelines.
The roots also didn't come up when a PG&E representative explained the reason for removing trees to the Pleasant Hill Cohousing residents, according to Fuller. She recalled the reason was so PG&E could have a helicopter come over and survey the pipeline.
By the time PG&E came to the Pleasant Hill City Council meeting on April 7 to discuss the need to cut down 180 trees there, the utility's main focus was on the threat from tree roots. The steel pipelines are wrapped in a protective coating that tree roots can damage, possibly leading to external corrosion, according to the utility.
Pleasant Hill Mayor Tim Flaherty asked whether the driving force behind the project is the danger the tree roots pose to the pipeline or gaining the ability to visually inspect the gas lines. PG&E Vice President Kirk Johnson, responded unequivocally, "It's the roots."
PG&E commissioned a study on the potential for tree roots to interfere with pipelines.
"We received the tree root study at the end of January, so the (Pipeline Pathways) program had already started. This is one part of it," Felix said. "Tree roots can cause damage to the coating of pipelines which removes a layer of protection. It's the first line of defense against corrosion."
However, the study was inconclusive about whether the presence of tree roots, in fact, leads to corrosion. The study is clear if tree roots wrap around the pipeline and the tree falls, the pipe could be damaged.
The study recommends PG&E develop a plan for trees to determine if they pose a threat to pipelines that takes into account several factors, including tree species and coating type.
"The development of a risk framework will provide a defensible approach for evaluating and prioritizing trees located along the pipeline (right of way)," the study says.
In Concord, where the City Council passed a resolution demanding the utility stop all tree removals until certain conditions are met, the staff arborist is inspecting city-owned trees to determine whether they are likely to damage the gas lines.
"If the roots are not going to extend to a location near the pipeline, it's difficult for PG&E to suggest that particular tree poses any risk," City Attorney Mark Coon said.
Walnut Creek Mayor Pro Tem Bob Simmons argued most tree roots go no more than ¿3 feet deep and, according to the PG&E study, the average depth of cover above the pipe is 4.2 feet.
"(PG&E) is focused on wanting to be able to fly their route by helicopter," Simmons said. "And to do that they need the tree canopy cleared and that's what this is about."
Some cities have begun preparing their legal arsenal. Walnut Creek and Pleasanton recently authorized their city attorneys to sue the utility should it start chopping down trees.
"PG&E and its contractors could start work any day, so we need to be able to move on a moment's notice," Walnut Creek Mayor Kristina Lawson said.
Walnut Creek leaders have asked PG&E to sign an interim agreement not to contact residents, to comply with city tree protection laws and to work with the city arborist to inspect each tree targeted for removal.
"The ball is largely in their court at this point," Lawson said.
Contact Elisabeth Nardi at 925-952-2617. Follow her at Twitter.com/enardi10.