LEWISTON – A new riverside park near the historic Gas Patch neighborhood is under construction, as crews begin converting an old industrial site into green space.

The park, tentatively called Lewiston Gaslight Park, is the result of a reclamation project to clean up the former Lewiston Gas Works site on Lincoln Street. When finished, the park will provide a four- to five-acre green space along what city planners hope becomes a primary artery in and out of the downtown.

Now owned by Northern Utilities, the plant produced gas from 1854 until it closed in 1962. Coal tar, a byproduct of the gas-making process, sat in storage tanks at the plant for decades, according to Charles Moran, spokesman for the company. Potentially thousands of gallons of coal tar leaked into the ground from the old, unused tanks and migrated toward the Androscoggin River.

“We spent a long time studying the area,” said Paul Exner, an environmental engineer for Northern Utilities. Surface and ground water tests were done, as well as soil borings “to determine where the coal tar is laying now and whether there is a public health risk.”

Unless someone were exposed to the coal tar directly, there is no public health risk, said Moran.

To collect the coal tar, a 600-foot underground collection trench will be built near the riverbank, under the park. The trench will be lined with pipes. Sump pumps installed above the ground will pump the coal tar out of the collection pipes. Construction crews are installing the walls of the trench now.

“We’ll have to monitor it for years to see how much we collect,” said Moran. All the recovered coal tar will be sent off site to be recycled into other uses, such as paving and roofing materials.

Exner said he has seen no evidence that the coal tar has actually made its way into the river.

Once the trench is finished, crews will begin the second phase of the project, which entails covering coal-tar-coated wood chips that were buried near the riverbank. The chips – used to help clean the gas – were often dumped near the river when they were no longer needed.

“You can still see wood chips in the riverbank and they stink,” said Exner. “Our plan is to pull back and regrade the whole bank, cover it with plastic and build a park over it.”

Plans for the park show parking, landscaping, benches and a walking trail. Representatives of Northern Utilities met with a small group of Gas Patch neighbors Wednesday to go over plans and a timetable for the project.

Lincoln Jeffers, deputy director of community and economic development for the city, applauded Northern Utilities’ efforts to reclaim the land. The utility entered into a voluntary agreement with the state Department of Environmental Protection to assess and then clean up pollution at the site. The $4 million cleanup will be paid by Northern Utilities ratepayers.

“It’s great that Northern Utilities is taking proactive steps to make sure the pollution doesn’t get into the river,” said Jeffers.

The park should be finished by June. Northern Utilities has been demolishing old gas plant buildings at the industrial site directly across from the park area for the past year. Once the three-acre site is clean, Northern Utilities expects to lease the property to the city. Jeffers said it could be used for surface parking in the short term, and perhaps be the site of a new parking garage on a long-term basis.

“We’re increasingly regarding that area as a gateway for the city,” said Jeffers. If plans for a new turnpike interchange at Goddard Road succeed, then Lincoln Street could become a primary route for traffic in and out of town.