November 25, 2024
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Operating a landfill a complex job Proposed West Old Town site to mimic Hampden’s ‘well-oiled machine’

HAMPDEN – At the Pine Tree Landfill in Hampden, things run much like clockwork. The landfill has been in operation since 1975, and nearly 30 years of experience has resulted in a well-oiled machine, according to its operators.

Officials say the proposed West Old Town Landfill, if approved, will run in much the same way.

The state purchased the West Old Town Landfill from Georgia-Pacific Corp. on Feb. 5 in an attempt to help maintain jobs at the company by lowering its operating costs.

Casella Waste Systems Inc., which operates the Pine Tree Landfill, has been selected by the state to run the proposed West Old Town facility. Last week Casella and the state completed details of their operating agreement.

Casella gave the state the $26 million to purchase the landfill from G-P, which in turn agreed to use that money to build a biomass plant to cut energy costs. The mill also will get a reduced tipping fee from Casella.

“We’re going to be substantially improving the design of that facility,” said Don Meagher, manager of planning and development for Casella.

Meagher didn’t want to imply that G-P had done a poor job of operating the landfill, “but Casella is in the dump business,” he said. The landfill previously was used to dispose only of waste generated by G-P and Lincoln Pulp and Paper. Under the state’s ownership, Casella has applied to the Department of Environmental Protection to have the landfill’s purpose expanded to include in-state household waste, construction and demolition debris and incinerator ash.

Before trucks carrying waste are allowed into the Pine Tree Landfill in Hampden, they are weighed at the scale house.

“All waste that goes into the landfill has got to come by the scales,” Meagher said. “It’s weighed on the way in and out and the difference is what the trucks are charged.”

Drivers must present a pre-approved manifest to the scale master before they are allowed to enter the landfill.

“It’s essentially all pre-approved,” Drew said. “Without the proper information when you get to the window, you don’t get in.”

All incoming waste streams must be tested by a certified lab and approved by landfill officials before it is allowed to be transported. A representative sample of the waste stream to be disposed of is sent to the lab and tested for a variety of chemicals.

The waste generator is responsible for the testing, and must sign a statement saying that the tested sample is representative of the waste stream they want to dispose of.

“If it tested out to be toxic, we could not take it,” Meagher said. There is no facility in Maine that can legally accept toxic waste.

The lab tests for the presence of a variety of chemicals. If even one of those chemicals is above the allowed threshold, the entire load is rejected.

“Nothing comes through the doors until I’ve looked at it,” Tom Gilbert said.

An average set of lab tests can cost anywhere from $1,000 to $1,200, he said.

“This gets a lot more complicated than most people would give us credit for,” Drew said. “If you want to come into this landfill with any kind of special waste, you have to call and obtain a manifest.”

Special waste is any discarded refuse that is not typically found in household, commercial or municipal waste. Special waste includes institutional waste, animal manure, ash, incinerator residue, waste treatment plant sludge, asbestos and other waste that requires special handling or approval from the DEP. It does not include mill waste or biomass ash.

Although Casella officials have said that all waste going to the West Old Town site will be generated in-state, residents are concerned that other waste also may be deposited there. The only waste that may come from out of state would be residue from out-of-state waste burned at the PERC or MERC plants. Once the waste has been burned in an in-state facility, it is considered in-state waste, Meagher said.

Drew said transporters of all waste, including construction and demolition refuse, must show legitimate manifests at the proposed site.

A state-certified scale master is in the scale house 24 hours a day, seven days a week for security purposes, and also to handle any complaints regarding the landfill, such as odor. Pine Tree receives about four odor complaints per year, Drew said. Those complaints come mainly during the hot summer months.

Pine Tree Landfill has a misting system in place that helps to minimize odors and when a complaint is received, officials do their best to determine the source of the odor and control it if possible.

In Hampden, a town official is trained to classify odors so they can assist with complaints that come in during the day. The system has worked effectively in Hampden, Drew said, and the company would like to mimic it in West Old Town.

“That way it’s not just us that’s making the determination; it’s the municipality as well,” Meagher said.

Once through the gates, covered trucks remove their tarps and proceed to the unloading site.

Operators at the site monitor what comes out of the trucks as they move trash around with backhoes and excavation equipment in order for large compactors to compress the waste.

Casella has the right to make a truck reload and take back waste if operators don’t like what they see. Drew said that there have been a few occasions when he has asked drivers to reload their trucks and leave the site. He did not have an exact number.

“Overall, all the generators that are hauling in here are pretty reliable,” Gilbert said.

“They have too much to lose,” agreed Drew.

Universal waste, such as fluorescent light bulbs and computer equipment, can contain mercury, lead and other harmful metals and pose the biggest problem right now because there are very few places you can legally dispose of it, Drew said. It is not accepted at Pine Tree and will not be accepted in West Old Town. There are still a few places in the state where universal waste can be disposed of, and a complete list is available on the DEP’s Web site at www.maine.gov/dep.

The business has changed a lot since the landfill first opened in 1975, Drew said, and more improvements are still to come. By this fall, officials plan to be generating electricity using the gases released from the landfill.

“What we have here at Pine Tree and what we are proposing to install at West Old Town is called an active gas management system,” Meagher said. The system would utilize the methane and hydrogen sulfide that is currently collected from the landfill via a pipe system pumped to a central location and burned off. The new system would convert the gas to electricity.

The power generated is a green source of power, meaning it is renewable, and is being heavily promoted by the state.

Original estimates reported that the flame would produce 1 megawatt of electricity. The company that Casella plans to sell the gas to has recently upgraded the size of the system they are planning to install and those initial estimates have increased, Meagher said.

“We sell them the gas at a pre-determined rate and they then market the electricity on their own,” he said.

At its busiest, the Pine Tree Landfill takes in about 25,000 tons of waste a day. The winter months are a little slower because not as many people are building. That in turn lowers the amount of construction and demolition waste coming in, decreasing the overall amount of waste to about 13,000 tons per day.

“The whole secret here is to get it compacted as tightly as you can,” Drew said. PERC ash is one of the best materials to fill landfill space because of its high density.

The recent high winds and cold temperatures have made it difficult for landfill officials to take care of waste – mostly loose paper, plastic bags and cardboard – that has blown around the site. Litter fences trap as much of the blowing debris as possible, but plastic bags hang in surrounding trees like parachutes stranded by the wind.

West Old Town is a far different configuration, and officials said they don’t expect as much wind at the site.

Casella officials also plan to make several changes to the existing West Old Town site, which they say will greatly improve the efficiency and environmental safety of the landfill.

The most significant of those changes is to get rid of the existing leachate pond and replace it with a leachate storage tank like the one used at Pine Tree. Meagher said this will significantly cut down on odors emitted from the site, in addition to adding further protection against leaking.

Pending DEP approval of the amendment application, Meagher said construction will begin at the West Old Town site as soon as possible. The application would make it possible for additional waste streams, other than just mill waste, to be accepted at the landfill. It also requests permission to increase the height allowance of the landfill to 390 feet above sea level, which would make it about as tall as the Hampden landfill. The Old Town site, at capacity, would be 180 feet above ground level.

A new cell needs to be built, the entrance road has to be paved and scales must be installed before full operation can begin, Meagher explained. He did not estimate a time frame in which all changes and modifications would be complete.


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