From hated neighbor to community contributor Haverhill landfill captures enough methane to power 2,000 homes

HAVERHILL — For years, it was an eyesore on the banks of the Merrimack River that gave off an intolerable stench.

Neighbors marched on City Hall, demanding the owners of the Ward Hill landfill be ordered to control the trash mountain. Families said it forced them to close their windows during the summer to avoid its foul odor.

That was in the 1970s and 1980s. Now, the landfill is covered and the trash rotting underneath quietly provides enough energy to power more than 2,000 homes.

The Covanta energy company, which bought the landfill and adjacent trash incinerator from Refuse Fuels, has installed a system to capture the methane gas produced by decomposed trash in the landfill and convert it to energy.

Covanta covered the landfill with a layer of plastic to stop the escape of methane gas into the atmosphere. The company then installed a piping system that draws the gas out of the landfill. The gas is filtered and burned in a methane gas generator that produces about 1.6 megawatts of power.

"As the waste decomposes, it creates methane, which is the same gas as natural gas," said James Lynch, facilities manager for Covanta. "It's clean renewable energy, and it should be producing methane for at least 10 or 15 years or more."

Covanta officials said the old landfill dates back to the 1970s when Refuse Fuels, which then owned the property, began dumping raw, shredded trash. It grew into a small mountain covering about 70 acres.

Covanta's main method of producing energy is by burning trash in its incinerator at the edge of the Ward Hill Business Park. That produces electricity, which is fed into the National Grid.

Besides the power generated by methane gas and burning trash, Covanta is also testing whether enough wind blows through the area consistently to provide power for windmills, known as turbines. A small wind-turbine was installed on the company's roof two years ago. It generates about 10,000 watts of electricity when the wind is blowing steadily — enough to illuminate 100, 100-watt light bulbs.

That power output pales in comparison with the power that would be generated by a larger turbine Covanta hopes to build on its site. Paul Bergman, president of Bergman and Associates in Haverhill, said his company plans to erect a wind-monitoring tower on Covanta's old landfill in a month or so. The study would continue for about a year.

"A large wind turbine would be erected on the ash cell, which is where Covanta dumps its incinerator ash," he said. "The economics of wind energy is directly tied to the average wind speed at a given site."

Bergman said Covanta's total annual power output would be equal to that needed to power the entire city.

Ken Nydam, business manager for Covanta, said his company is always looking at new technology to increase its electrical power output.

"This may include using the landfill as a site for a 1.5- to 2.5-megawatt windmill, which would be much larger than the one we have now," he said. "We're currently studying wind speeds at our site."

Nydam said all three power generation sources at Covanta help reduce greenhouse gas emissions.

"The windmill does not use any fossil fuel," he said. "The landfill gas, or methane, is 23 times a more powerful contributor to global warming than carbon dioxide if it is released into the air. And for every ton of trash we process, we avoid the need to import one barrel of oil or mine one ton of coal."

*The company has one small wind turbine and is considering installing a larger one on top of its landfill.

Photos

James Lynch, facility manager for Covanta energy company in Haverhill, checks the filtration system that filters methane gas produced by the landfill. The gas is then converted to electricity. Staff photo

Covanta energy company in Haverhill has installed a system that captures methane gas from the Ward Hill landfill and converts it to energy. Staff photo