An islander’s concerns about herbicide use at the Maury Island Marine Park have prompted changes in the use of chemicals in King County’s restoration efforts there.

Now, when workers deem herbicides necessary, they will not spray herbicides but instead will use a more targeted application technique, and county officials will improve public information at the site and conduct a soil and water test for the herbicide. These changes came about after islander Frank Jackson, who is the chair of Vashon-Maury Island Groundwater Protection Committee, went for a walk at the park recently and found workers there spraying blackberries.

The park is a 300-acre expanse that features stunning views of Puget Sound and Mount Rainier, but was a former mining site, and until the county began restoration efforts there last fall, it was overrun with invasive plants. The county purchased the park to benefit the shoreline, the near shore and the upland habitat, according to Tina Miller, who oversees the project through King County’s Department of Natural Resources and Parks.

While Jackson has high praise for the extensive restoration work completed so far, he is concerned about chemicals in the environment and sounded an alarm, talking to county officials and bringing the issue to a July meeting of the groundwater committee.

“I felt that they are leaving a toxic chemical legacy for everyone unnecessarily,” he said in a recent phone interview. “Is that going to have a zero effect on the marine environment right down the steep slope? I don’t think so.”

The product in question is Garlon 3A, a broad-spectrum brush and broadleaf herbicide with the active ingredient triclopyr. Jackson said in his research about the herbicide, he found a report from the state of Oregon, indicating that in tests, triclopyr has been found to increase the incidence of breast cancer in mice and rats and negatively affected fish, frogs and birds.

Miller, on the other hand, said she believes the use of the herbicide is safe and that it is being used judiciously. Workers at the park have removed the bulk of the blackberry and Scotch broom manually, she said, and have resorted to chemical use to eradicate blackberries in a limited area. She also said the goal is an important one: a forested, restored area.

“Unless you use chemicals, blackberries come back,” she said. “We would lose our planting effort we had completed.”

Miller attended the recent groundwater protection meeting at Jackson’s invitation and shared with the group the scope of the project and the efforts there.

Since the project began last September, workers have cleared 37 acres, including 10 acres of blackberries and 21 acres of Scotch broom, mostly by hand, Miller said. On roughly 9 and a half acres, workers sprayed 3.3 gallons of the herbicide on the blackberries, and on another 2 acres they relied on the more conservative cut and wick method and used roughly one-third of a gallon. Additionally, she said, they have used the product in the weakest possible dilution and at a fraction of the legal limit allowed.

A 37-acre project is a large one for restoration efforts, she added, and while mulching is doing a fairly good job of controlling the Scotch broom, the blackberries that had been removed are starting to come back, she said.

Miller also stressed that the use of herbicides is intended as a short-term measure.

“It’s not like you are going to have to be treating blackberries forever,” she said.

At last month’s groundwater committee meeting, some members asked for more signage and for more information to be put on the county’s website, and she said she expects those requests will be fulfilled without trouble.

“We’ll work on it,” she said. “That is very easy to do.”

She also noted that the county will now do sampling of the site to test for triclopyr and its breakdown products — a step it had not planned on. Staff will take a composite soil sample and a water sample this fall after what is called the “first flush” of rain.

“It is not required, but I think it is a reasonable thing to ask of us,” she said.

While Jackson said he appreciates the steps Miller and the county are taking, he remains concerned about the consequences of using herbicides and noted the history and tasks of the groundwater protection committee, which advises King County on issues related to groundwater.

“We work pretty hard to make people aware that when they use an herbicide or pesticide … it’s not going away. Many times it persists in the environment, in the groundwater or Puget Sound. It tends to be cumulative and irreversible,” he said.

Puget Sound, he added, is said to be dying a death by 1,000 cuts.

“We are administering yet another cut,” he said.

Jack Barbash, an islander who has worked for the federal government as an environmental chemist, including with pesticides and groundwater, called the restoration efforts at the park heroic and impressive, but spoke to the complexity of the questions herbicide use raises — and the importance of paying attention at the Maury Park.

“We should be attentive about it,” he said.

If chemicals are deemed necessary, he said, then questions need to be raised about their potential harm. It is not just the active ingredient that might cause harm, he noted, but so-called “inert ingredients” in a product, which sometimes make the active ingredient more toxic than it is on its own.

He noted he was pleased that the county will test at the site, but he cautioned that it is very difficult to test for the inert ingredients. He also noted that triclopyr has a half life of 39 days, and it has been found in Puget Sound.

Scientists are beginning to understand more about individual pieces of information regarding toxins in the environment, but, he said, it is not yet possible to provide concrete answers that would be helpful to know in instances such as this one.

“We still need to connect more dots,” he said.

For Jackson, the lack of concrete, scientific answers is part of what is so disturbing about introducing toxins to a natural environment while restoring it.

“The most worrisome thing is how many things are unknown,” he said.