Gazing at the crew hammering the panels onto aluminum racks at the top of the mounded landfill last week, Todd Hranicka, director of solar energy for Public Service Electric & Gas Co., marveled at how far the L&D Landfill had come. "It is the largest Superfund landfill solar project in the country," he said.

Hranicka said it had not been difficult for PSE&G, the state's largest utility company, to obtain approvals because the landfill was "in compliance with Department of Environmental Protection and Environmental Protection Agency rules." Monitoring of the site is ongoing, while harmful exposure to humans has been brought under control, according to the agencies' reports.

"We're repurposing land that has no productive use," Hranicka said. "And we're bringing renewable energy to residents of New Jersey."

Next month, a sea of solar panels is expected to be in place, standing neatly in long rows, ready to harvest the sun's rays and convert them into electricity. The solar energy will be added directly into the grid, on-site, Hranicka said.

Workers supervised by juwi, a global renewable energy company based in Germany, are erecting the panels on a 53-acre section of the landfill, off State Highway 38 and straddling Mount Holly, Eastampton, and Lumberton Townships. PSE&G also is considering using more acres of the landfill in the future, Hranicka said.

In 2012, the Christie administration established a public policy in which future solar farms would be located on landfills and brownfields, shifting away from agricultural fields. Hranicka said the decision was made to preserve farmland.

PSE&G operates three other solar farms on landfills, located in Bordentown, Deptford, and Kearney, but none of those were on the Superfund list. There are already eight landfills in New Jersey with solar projects, according to the DEP.

The L&D project will be PSE&G's largest solar farm, in terms of the number of panels and output, Hranicka said. He declined to divulge the project's cost.

The EPA says more than 25 Superfund sites across the country have solar farms. Among them is the York County Solid Waste and Refuse Authority Landfill in Stewartstown, Pa. "Superfund sites can be well suited for alternative energy production," the agency said in a report.

Waste Management of New Jersey, the parent company that owns L&D, leased the property to PSE&G for 20 years for the solar project, with an option to extend it for an additional 10 years. "Waste Management is proud to partner with PSE&G on this important project," said John Wohlrab, director of government relations, in a statement. "The former L&D landfill will have a productive new life as a solar farm."

During a visit last week to the L&D solar farm, electricians with IBEW 351 were positioning the panels on 4,600-pound concrete ballasts. "This place is a dump," Bob Giandomenico said, chuckling. He said it was his first time working atop a landfill and he called it "different and interesting work."

Al Pellegrini said he had erected solar panels on roofs and farms, but this was his first time participating in a landfill project. "This is definitely more challenging," he said. "We can't penetrate the ground because of the cap, and it's harder to get everything level and square because of the contours of the ground."

To protect the clay cap of the landfill, the concrete ballasts had to be laid on the surface first. To expedite the project, the cement was poured into the ballast shapes on-site and then the racking system for the panels was attached.

Menacing black clouds moved in that day, but Hranicka said that the rain was actually somewhat helpful to solar farms. Though the rain stops solar production, it keeps the panels clean, he said, noting that in Arizona, workers are paid to wash dust from the panels.

New Jersey, he said, is the third-ranking state in the country - behind California and Arizona - in solar-energy production.

"Ten years ago, would you have thought all this was going to be here?" said Fran Sullivan, spokesman for PSE&G, at the L&D site.

In the early 1940s, the L&D Landfill was a sand and gravel pit, according to a federal EPA report. Later, it became a dump for demolition debris and then was used for municipal trash and industrial waste. Sewage sludge also was treated on-site.

The Landfill & Development Co. acquired the property in 1971 and operated it as a landfill until 1986, when it reached capacity. After it was added to the Superfund list, the EPA ordered a collection system to be installed to capture pollutants from the runoff water and a methane gas collection system. These systems and the underground pumps are still operating.