By Noelle Annonen

An essential part of home care is cleaning out the old to make room for the new. But what happens to the things we dispose of once they’ve been placed in the trash bin on the curb?

Sandwich

Aside from private contractors who pick up curbside solid waste for residents on their own terms, the official Town of Sandwich contract is with SEMASS Covanta, says Paul S. Tilton, the department of public works director and town engineer.

Sandwich’s trash goes through a drop-off at the town’s transfer station. Residents with a sticker for the station can drop off their household garbage on Route 130, where SEMASS Covanta will collect it and bring it to its waste-to-energy facility in Rochester.

Waste-to-energy facilities, like the one Covanta operates, divert waste from landfills to use for generating energy. According to the company, it takes municipal, nonhazardous solid waste, like what it gets through its contract in Sandwich, and combusts it. That combustion generates steam for electricity production. The company boasts powering 1 million homes using the energy it generates.

Covanta disposes of other materials, from liquid waste to plastic to metal. According to a 2013 report by the Center for American Progress, solid waste processes at waste-to-energy facilities reduce greenhouse gas emissions by one ton per one ton of waste. This is because the facility avoids using methane, like that produced in landfills. Additionally, it offsets emissions from fossil fuel electric production, according to Covanta.

Philip A. Goddard, manager of facility compliance and technology development at the Integrated Waste Management Facility in Bourne, said SEMASS’s waste-to-energy facility is one of the five of its kind remaining in the state. He added that the residual waste, left over from Covanta’s combustion process, comes to the landfill that he helps manage.

Bourne and Falmouth

Residents in Bourne and Falmouth do not have to drop off their household waste at their towns’ respective transfer stations. The Integrated Solid Waste Management facility (ISWM) on MacArthur Boulevard is one of 10 operational landfills left in the state, according to the Environmental Protection Agency.

Kari Parcell, a municipal waste expert for Barnstable County, said the state issued moratoriums around the building and use of waste-to-energy facilities due to concerns that the air around the facilities is not particularly clean. Meanwhile, Bourne’s ISWM has “one of the most state-of-the-art” facilities, regulating above Massachusetts Department of Environmental Protection standards, Ms. Parcell said.

“Dumps 50 years ago were just throwing [trash] in a hole in the ground,” Mr. Goddard said. “We don’t do that anymore.”

Mr. Goddard reported that the ISWM manages 600 tons of waste per day, which comes out to around 218,000 tons annually. Residents in both Bourne and Falmouth enjoy a two-cart curbside collection system; one 96-gallon cart for recyclables and another cart for garbage. Falmouth uses a contractor, Nauset Disposal, and Bourne uses its department of public works for collection.

Each trash truck drives over a scale before entering and leaving the ISWM facility and the drivers identify their company and the town they serviced for tracking waste. Recycling moves through the ISWM to a contracted processor, which separates different commodities to be sold in their respective markets, from recycled paper products to plastic and more.

Municipal trash is put through a compactor, which crushes the waste into a specially designed shape that fits into a highly engineered puzzle before it is deposited into the landfill. Mr. Goddard said an engineer directs operators on how to shape and place compacted waste into the landfill to ensure that waste is stabilized and the area is prepared for the following day’s waste.

Mr. Goddard said landfills have a footprint and vertical volume that is filled over time before it is sealed and managed forever. To use that volume strategically, engineers work to fill a theoretical shape of volume, which he described as a 1 million-cubic-yard, 3D trapezoid. Engineers work to safely densify trash while also filling the theoretical space in that trapezoid as efficiently as possible.

“Much like if you were putting your trash in your kitchen garbage bin and you step on it after a while,” Mr. Goddard compared the landfill to a typical overflowing, household garbage can: “You don’t just put (trash) in loose without trying to get more in there and bring it out to the curb.”

Each day, operators cover the daily load of garbage that was handled. The covered structure is designed to shed clean, uncontaminated rainwater from its surfaces. Rainwater is also diverted from the waste as much as possible and any contaminated water is collected, he said. Each structure is controlled entirely, from gas to odors. Emitted gasses are collected in piping and destroyed in a flare before they can reach the atmosphere, Mr. Goddard said.

“It’s a very methodical, well-planned, orchestrated and engineered process,” Mr. Goddard said.

Mr. Goddard anticipates that the ISWM in Bourne will continue filling up for another 20 years or so. He added that some waste contractors must haul municipal waste to a landfill in another state as landfills are filled up and closed.

Mashpee

Mashpee, like Sandwich, offers a drop-off at a transfer station rather than collecting at the curb. Waste Connections is contracted to collect waste from the drop-off and the company rail-hauls and trucks the waste out of state when in-state landfills reach daily capacity, Ms. Parcell said.

Ms. Parcell added that diminished capacity for solid waste has been a challenge on Cape Cod since she began working for the county seven years ago. Mashpee is not the only town with a contractor that must take its waste out of state. She said officials throughout the commonwealth hesitate to permit expansion of existing or construction of new landfills, limiting places where municipal trash can be dropped off and managed.

“We’re still generating the same amount of trash,” Ms. Parcell said. “But we don’t have anywhere to take it.”

Ms. Parcell said Barnstable County is currently in a 10-year rotation of a master plan, aimed at decreasing its solid waste of all kinds that is generated significantly over time. While the previous waste audit found that solid waste has increased in Barnstable County over the audit before, the contributing factor was contaminated soil and destruction debris, rather than municipal waste.

The county is working on outreach and education to encourage Cape Cod residents and schools to recycle and compost as much as possible, rather than adding to the solid waste tonnage, Ms. Parcell said. She added that many Cape towns are working independently on passing zero-waste initiatives, bans on single-use plastic, like nips and plastic water bottles, and other initiatives to contribute to decreasing household waste output.