After more than two years of planning and a delay caused by the discovery of a rare plant, the Gay Head Light relocation project got under way early this week — and then encountered a new hurdle with the discovery of soil contaminated by lead.

The company Tetra Tech, along with John Keene Excavation in West Tisbury, are now working to further define the area of contaminated soil. Permanently removing all the soil is estimated to cost about $600,000, but most of the soil is expected to be removed only temporarily. The contamination is not considered a health risk, but creates another hurdle for the much-watched project to move the old lighthouse away from the edge of a rapidly eroding cliff.

Len Butler, chairman of the lighthouse relocation committee: "Everything is full speed ahead." — Timothy Johnson

The areas of highest contamination appear to be around the site of an old lightkeeper’s quarters and is likely the result of lead paint, said Richard Pomroy of Pomroy Associates who is general manager for the project.

On Monday morning, the sounds of brush cutters, chain saws and jackhammers came down from the small hill where the lighthouse stood beneath a darkening sky. Four companies were busily preparing the structure and its surroundings for the move, expected to begin in late May.

Workers from Landscope in Edgartown were clearing away brush and digging up shrubs and other plants from around the site. Much of the existing vegetation will be stored in a fenced-in area at Aquinnah Circle and replanted after the move.

Some 700 rectangular oak blocks were stacked in neat bundles along the road. The blocks will be used as cribbing to support the lighthouse while steel beams are inserted beneath the foundation. Special hydraulic jacks will slowly push the lighthouse along a bed of steel beams to its new location about 135 feet to the east.

International Chimney Corporation, which will handle the move, was preparing the structure inside and out. Loose mortar already has been replaced, and on Saturday the second level of the lighthouse, just below the light room, was fitted with a wooden corset, held tightly by cables. Inside, a worker in a white jumpsuit was pounding away at a concrete block with a jackhammer.

“It’s exciting after two and a half years of planning and testing and everything to actually be making it happen,” said Len Butler, chairman of the lighthouse relocation committee, who was on site Monday.

The lighthouse wear a wooden corset, and surrounding land is dotted with markers. — Timothy Johnson

Many wooden stakes with colored ribbons marked the boundaries of the excavation, old foundations and other features. Larger stakes marked the center of the new foundation, and an observation well that will detect groundwater. The 1856 brick and mortar lighthouse stands just 46 feet from the eroding cliffs.

Work had been delayed a few weeks this spring after the site was identified as containing habitat for the endangered broad tinker’s weed. But late last week the state Division of Fisheries and Wildlife approved a mitigation plan that involves placing nearby habitat into conservation. The town of Aquinnah will place 2.1 acres near the lighthouse into conservation, as an alternative to a site survey that would have taken place in June, when broad tinker’s weed appears.

“Everything is full speed ahead,” Mr. Butler said Monday.

Then at a selectmen’s meeting Wednesday, the new setback surfaced as the board discussed the contaminated soil issue.

The selectmen have signed an addendum to the town’s contract with Tetra Tech that includes an additional $91,800 for lead mitigation. Town administrator Adam Wilson said the Department of Environmental Protection had initially been in favor of removing all of the contaminated soil.

“We clearly argued that a high percentage of the soil is not contaminated,” he said, also noting the high cost of removal.

Another contractor, GEI Consultants Inc., which is working with Tetra Tech on a schedule of services and has oversight of soil disposal, will require another $42,600 for the mitigation work.

“The tinker’s weed was one problem but this lead soil was another animal altogether,” Mr. Wilson said.

Lighthouse keeper Richard Skidmore. — Timothy Johnson

Among the many other contractors for the project, Public Archaeology Lab of Pawtucket, R.I., has surveyed the area and mapped out the brick foundation of the former lightkeeper’s building. A member of the Wampanoag Tribe of Gay Head (Aquinnah) was present Monday to observe the excavation.

Workers in green Landscope sweatshirts were unrolling silt fencing around the site perimeter and lugging clumps of Panicum grass, wrapped in burlap, down from the hillside.

“Ultimately the landscaping is going to be minimal,” Mr. Butler said, noting that the goal was to preserve the site’s original character. He added that some of the broad tinker’s weed would likely survive the transport as well.

A time-lapse camera will be installed on a 12-foot pole just east of the new location, and a live webcam will be installed at the bottom of the Circle, looking up toward the lighthouse.

Some work had continued while the town waited for the final state approval. Two weeks ago, the U.S. Coast Guard fully extinguished the Gay Head Light, for the first time since 1989, and activated a temporary beacon near the shops at the Circle. Last week the company Radar Solutions scanned the old foundations, including one that supported a shorter brick lighthouse during World War II. That foundation will be removed, since it is within the excavation area.

Radar Solutions also investigated an underground structure just west of the Gay Head Light, which has been exposed in recent years and now protrudes from the cliff. “It turns out it wasn’t very big,” Mr. Butler said. He was still waiting for the final results.

An earlier landscaping plan called for the preservation of the original granite foundation for use as a circular bench to memorialize the 1856 location. But International Chimney now plans to move the entire foundation, which includes two courses of granite and extends about four feet underground.

A new granite bench will mark the original location, Mr. Butler said.