Hundreds of pine trees appear to be dead or dying near the Birmingham Water Works’ Shades Mountain Filter Plant, but the utility says a chemical spill that occurred at the plant last month is not responsible.

Three weeks ago, on Feb. 27, chlorine gas was released from the plant into nearby areas, sending 55 people to the hospital and forcing U.S. Highway 280 to shut down in both directions for nearly two hours.

Nearby residents were told to stay inside their homes for several hours after the incident to avoid coming in contact with the toxic gas. Now some of those residents believe the incident is connected to the large swaths of pine trees nearby whose needles have completely turned yellow or brown instead of their normal, ever-green color.

Birmingham Water Works spokesman Rick Jackson said the Water Works has been contacted about dead trees in the area, but denied that the accident or the plant had anything to do with the situation.

“It definitely isn’t anything associated with Birmingham Water Works,” Jackson said. “That’s not our issue. It’s not because of what happened at Shades.”

UPDATE: The Water Works now says it is investigating the trees near the accident site.

Jackson said Tuesday the incident was still under investigation, but that the people taken to local hospitals were released by the next day and all Water Works employees were back at work by the Monday after the accident.

At Valley Christian Church, which borders the plant on one side, the pine trees on and around the church property appear to be in serious distress. The needles on the trees have all turned brown, and many of them have begun to fall off.

Linda Reeves, a volunteer member of the church’s property committee who tends the grounds two or three days per week, said the church has 62 pine trees on its grounds, and all of them are showing similar symptoms.

Reeves said she first noticed something was amiss on March 9, about a week and a half after the accident, when many of the needles of a stand of young pine trees across the fence on Birmingham Water Works property began turning an unusual yellow color. Within two weeks, Reeves said, the mature trees on the church property had all turned brown.

“I just wanted to break down crying when I saw it,” Reeves said.

Across a fence separating the church property from the plant, a row of young pines, 6-7 feet tall all appear to be brown and dying. On the other side of U.S. 280, several dozen pine trees closer to the road appear to be browning, while those further up the hill appear unaffected. A clear line between green and brown stands out on the hillside.

Behind the church, Cherokee Road winds through a Mountain Brook neighborhood nestled between U.S. 280 and the back side of Brookwood Mall. Several pine trees throughout that neighborhood also appear to be affected, including two on the property of Kaity Blackman.

Blackman said she first noticed the symptoms on her trees about two weeks ago, and that the trees have gotten worse since then.

Blackman, who is pregnant with her second child, says she is thankful that she was out of town when the accident occurred, but is worried now that two 60-foot pine trees looming over her house appear to be dead. She fears that she will now have to spend thousands to have the trees removed before they fall, potentially on her house.

“It would just be a nightmare to have to deal with,” Blackman said.

Chlorine gas can be harmful or fatal to trees, according to a recent publication from Kim Coder, a professor of tree biology and health care the University of Georgia’s Warnell School of Forestry and Natural Resources. The gas is absorbed through the leaves and can cause short-term and long-term impacts.

“Trees exposed to chlorine gas vary in their reaction ranges from no visible symptoms to death,” Coder writes.

Coder writes that certain species, including most pine trees, are particularly vulnerable to chlorine gas. The gas is absorbed through the needles or leaves and mixes with water inside the leaf cells, creating hydrochloric acid. This lowers the pH of the cell and can result in the total loss of the affected leaves or the death of the entire plant.

Jim Jacobi, a specialist with the Alabama Cooperative Extension System, inspected the trees at Valley Christian Church from the ground and said it’s possible some of the trees may survive. Jacobi specializes in general tree health, not specifically chemical damage, but said there is a chance some of the trees will bounce back.

“I’d say we’re in ‘wait and see’ mode,” Jacobi said. “It depends on whether they’re able to put out new growth.”

If the trees are able to grow new needles in the next three to four weeks, Jacobi said, that new growth may provide enough energy via photosynthesis to keep the tree alive. Unfortunately, Jacobi said pine trees don’t survive very long without living needles.

Reeves and Blackman are hoping that their trees recover.

The church recently cleaned out and restored a seasonal stream bed running past the church toward the highway and built a walking trail and natural area around the property. Reeves spent Tuesday afternoon planting new blueberry bushes in a garden along the walking path, next to the playground.

“We really just felt sad because we care about the outdoors, and the environment that God provides,” she said. “We love having that quiet space outside to walk or pray or just be in the outdoors.”

Blackman said the Water Works has always been a good neighbor to the church, but dealing with 62 dead pine trees would be a significant burden for the congregation.

“We don’t blame anybody,” Reeves said. “This was just human error and these things happen. We just have to figure out what to do at this point.”

*This post was updated on March 21 to reflect that the BWW is investigating the situation.