A large property on Washington Street has been found to be significantly contaminated with coal tar residue and former owner Central Maine Power Co. will assist with the cleanup.

The property includes a couple of run-down buildings and vacant parcels and is located across the street from Belfast Skate Park. It is currently being used as a storage area of Trustworthy Hardware but was historically the site of Belfast's power station.

A manufactured gas plant was in operation on the site from the mid to late 1800s to about 1921. Coal tar is a waste product of the gassification process. The Gas Co. property was acquired by Belfast Light and Power Co. in 1895, by Penobscot Bay Electric Co. in 1909, and by CMP in 1921.

A nine-month environmental assessment by city consultants Ransom Consulting of Portland found asbestos and lead paint in the buildings, petroleum near a former underground storage tank, and chlorinated volatile organic compounds, or VOCs, — that probably originated off-site — in soil vapor.

Coal tar residues were found in soil and groundwater in the area of a former concrete bunker that housed the manufactured gas plant, and the residues had leached beneath Washington Street. None were found in groundwater or soil at the skate park or other city properties across the street.

"It is inferred that free-phase coal tar and dissolved-phase coal tar constituents do not extend to the north of Washington Street," the Phase II assessment report states.

The coal tar does not pose an immediate risk to public health, said Tracy Kelly, a project manager at the Department of Environmental Protection's brownfields program, because the residues are located below the surface, generally at a depth of two feet. Also, homes and businesses in the area are connected to the Belfast water supply, and are not accessing groundwater. However, the soils will have to be cleaned up before redevelopment to protect construction workers.

Regarding VOCs, she said: "The concern would be that [they] might cause an indoor air issue. However, potential vapors, whether they exceed safe guidelines or not, will be addressed … by a requirement that any new buildings constructed on the property contain a vapor mitigation system."

Kelly said the other contaminants detected on the property are typical of a commercial property located in an urban area and also do not pose an immediate danger to public health.

The current owners have been planning to redevelop the site with a new building or "something more suitable for the area," but cannot move forward until the contamination is dealt with, Trustworthy Hardware owner Eunice Palmer said.

Central Maine Power has taken responsibility for the soil cleanup through the "limited soil removal" option in which the most heavily contaminated soil is removed and the rest is managed using such techniques as covering with asphalt, clean soil or a building.

CMP will remove eight to 10 feet of soil, more than was recommended by the consultant, and store it at a secure site. City Planner Wayne Marshall said the cost of the soil removal could amount to approximately $500,000. Removing all the contaminated soil would cost $1.9 million, he said.

At a meeting Oct. 21, the city council discussed the need to move utility poles to make room for remediation and redevelopment activities. Marshall told the council that CMP has the authority to move poles temporarily and will come to the council at a later date with a plan for a new arrangement of the poles.

Even with the help from CMP, the cleanup will be a great expense — approximately $450,000 — for the current owners. They will be responsible for removing asbestos and lead paint, demolishing buildings, and installing vapor barriers in new buildings. They have hired a contractor and engineering firm to estimate the cost of demolition and redevelopment, and are looking to secure a low-interest loan to carry out the work, Marshall said.

"I would like to commend the property owners for engaging in this conversation and the expense they're going to," Councilor Mary Mortier said. "It is a large property, and it is a very important piece of property in the downtown. Even though we don't treat it that way today, it was in the past and will be in the future."