Five months after state environmental regulators first warned Coastal Maine Botanical Gardens and its contractors of violations found at the site of a $30 million expansion of the Boothbay attraction, the state has issued a formal Notice of Violation of four federal environmental laws.

[Neighbors fight Coastal Maine Botanical Gardens’ expansion]

In a June 29 notice, Lucien Langlois of the Maine Department of Environmental Protection notified gardens executive director William Cullina, site contractor Crooker Construction, LLC, and construction manager Wright-Ryan Construction, of violations observed by an inspector on multiple occasions even after the department issued a Jan. 23 warning about the environmental impacts of the expansion work.

[Coastal Maine Botanical Gardens announces plans for major expansion]

According to Langlois’ letter, on at least four occasions, a third-party inspector saw instances of unclean water in protected wetlands and significant vernal pools; inadequate steps being taken to prevent erosion; and the unlicensed construction of a “plunge pool” in a freshwater wetland area, which is also within critical terrestrial habitat of a significant vernal pool.

The DEP notice goes on to say that sets of the contractor’s construction plans for the project, dated April 17 and May 20, were never approved by the state.

The notice alleges violations of the Natural Resources Protection Act, the Erosion and Sedimentation Control Law, the Protection and Improvement of Waters Act and the Site Location of Development Act.

“The nature and circumstances surrounding the violations discovered has led the department to conclude that final resolution of this matter should include monetary penalties as part of a civil penalty action,” the letter states. “The necessary next steps to finally resolving this matter will be discussed once you contact me within the timeframe provided for in the [notice of violation].”

But in a June 30 reply to the DEP, Jan Wiegman, project manager for Wright-Pierce, wrote that as of June 28, the third-party inspector had found erosion controls were now in compliance, and said Wright-Pierce and CMBG “are preparing a restoration plan” for one wetland area in question.

Cullina, of Coastal Maine Botanical Gardens, did not respond to emails and phone calls Thursday and Friday. But during a meeting Wednesday at the organization’s Boothbay office, Cullina pointed to months of satisfactory environmental inspections and said CMBG addressed each violation immediately after it was noticed. He noted that the May 26 violated resulted from a sinkhole forming after it rained more than two inches. The other violation, where a contractor cut down more trees than were approved, Cullina said “is the kind of thing that realistically happens in construction projects all the time.”

The controversial project has been criticized by neighbors and others, including the Boothbay Region Water District, since it was first announced in April 2016.

Most notably, Vaughn and Jodie Anthony, whose Gaecklein Road farmhouse abuts land clearcut for the expansion, spoke out in February about the loss of vernal pools and the ongoing blasting.

When the expansion is complete, the garden complex will include a new visitor center and gift shop, a restaurant in the existing visitor center, a 16,000-square-foot horticulture research and production facility, and a nearly six-story conservatory, along with expanded parking, formal gardens and trails.

But to make that happen, large swaths of wetlands — including 6.2 acres of “critical terrestrial habitat of eight significant vernal pools” — will be “permanently altered,” according to a permit from the Maine Department of Environmental Protection approving the project.

But Cullina said Wednesday that the language of the permit implies more damage than will occur, and said that in some cases, “permanently altered” will mean improved.

After working with the U.S. Army Corps of Engineers, he said, the project will only fill in “insignificant wetlands created by previous construction,” and “will not fill in or impact any vernal pools or ‘significant wetlands.’”

The overwhelming success of the gardens’ annual holiday light show, Gardens Aglow, which this year drew 75,000 visitors, has generated buzz about the gardens and fed plans for growth that executive director William Cullina said in February is necessary to accommodate those crowds — and the economic boon they bring to the region.

Despite objections — which included fiery letters to the local weekly newspaper, a boycott effort and an unsuccessful attempt to block the project with a restraining order — that the project would compromise nearby Knickerbocker Lake, one of two public water supplies for the area and that the permits were granted based on “faulty science,” the Botanical Gardens obtained local, state and federal approval.

The Boothbay Region Water District and the Anthony family filed separate appeals of the project, and the water district dropped its appeal after the gardens revised plans to move its septic system.

A June 26 public hearing held by the Boothbay Board of Appeals was continued to July 27.

In the January warning, Langlois wrote to Cullina, “At this time, the department is willing to resolve these violations without formal enforcement action provided that CMBG continues to inspect and maintain erosion and sedimentation controls to prevent any future sediment discharges.”

CMBG and its consultants must take immediate action on the violations: by Tuesday, they must install and maintain temporary erosion and sedimentation controls according to plans approved by the DEP; create and maintain a daily erosion and sedimentation control maintenance log; and submit either an after-the-fact NRPA permit application or a restoration plan, with restoration to be completed by Aug. 1.