Recycling Committee tours Reworld Incinerator

Chelmsford’s solid waste is delivered to the Reworld waste-to-energy incinerator facility in Haverhill MA. On June 9, 2025, Chelmsford Recycling Committee members and associates visited Reworld Haverhill to learn more about how our solid waste is handled. Here is a summary of our visit.

Information Session

We first met in a small lobby where each member of the tour had to sign a waiver. Our first stop was a conference room for an information session, where we met Chris and Dave. They began by offering a short video: a three-minute virtual tour providing a broad overview of the facility, the process by which waste is converted into energy, and how byproducts of this process are dealt with. After the video, they allowed us to ask questions about anything we would like. An informal discussion followed, during which they answered each of our questions in a remarkable level of technical detail. This discussion lasted about an hour.

They receive 100-200 trucks per day.  It takes about 1 to 2 hours for an item to travel through the system, which reaches 2000°F.  10 tons of trash reduces to 1 ton of ash.  After the material is burnt, magnets capture the ferrous metals and an eddy current system separates the non-ferrous metals (aluminum, copper, nickel, etc.).  The metal is sent to a buyer.  Some metals (mercury, arsenic, etc.) will vaporize in the heat and cannot be captured, so it’s very important not to put these materials in the trash.  Other items that should never be put in the trash include:  tree trunks and limbs (get stuck in the machinery),  yard waste (creates nitrogen oxide), tires (toxic when burnt), latex paint that has not solidified (makes a mess), large 5-gallon propane canisters (explodes, empty or not, and damages the equipment), white goods like washers and water heaters, non-alkaline batteries, hazardous waste, recyclables, and waste-ban items like mattresses and textiles.

Tipping Floor

Then the tour began, with Dave as our guide. He first took us to what is called the "tipping floor," where garbage is delivered to the facility. We were warned that there would be an odor, and it was indeed impressive, although not altogether unbearable. A single bulldozer was actively working the floor, pushing garbage into piles that were multiple stories high. A green laser projected onto the floor demarcated the boundary beyond which the piles were to be contained. Dave explained that occasionally a truck may get its rear tires stuck in a pile during the delivery process, which is one of the reasons they try to enforce the green line. A section to the side of the piles was designated for the separation of bulky metal items. Some birds could be seen pecking at a few things scattered around the floor; Dave was open with us about the presence of various animals. He indicated that while the animals aren't some kind of secret, one of the reasons they disallow photography during the tour is because a simple picture of a rat on the tipping floor is all it takes to make something go viral on social media.

Combustion Intake

We next took an elevator to the area by the top of the piles, where a large crane drops the garbage into a hopper that feeds the combustion chambers. Dave explained that, among other things, the crane operator needs to make sure that garbage gets spread out across the full horizontal dimension of the hopper intake, and that the mix of garbage going in is always equal parts wet and dry; too much of one or the other changes the rate of combustion and becomes more difficult to control. An interesting topic during this part of the tour had to do with the disposal of sensitive materials or controlled items by law enforcement and other government agencies or institutions. Reworld is compelled to comply with special procedures and realtime supervisory oversight whenever this occurs. One memorable example involved a load of casino chips and the accidental spillage of a crate of them while it was being loaded into the hopper; every last chip had to be individually located and disposed of.

Control Room

Dave then took us to our final stop in the tour, which was the control room. Chris happened to be running the control room today, filling in for its usual operator, and so we got to see him again. The control room somewhat resembles the flight deck of a spaceship in a Sci-Fi movie, with gauges, buttons, switches, knobs, and screens adorning the walls and consoles at each desk. Much of the instrumentation is for routine monitoring and control. Various digital readouts assist the control operator in identifying whether certain data measurements related to temperatures and emissions are within their ideal thresholds, and whether they are stable or trending in a particular direction. Cameras provide a live feed of each of the facility's processes, including the combustion chamber. Chris also spoke with some of us about his journey to becoming an engineer. He mentioned that the standards in Massachusetts are very high, and that this is excellent to ensure safety but also means he/Reworld often cannot hire applicants from other states. He said boilers are a waning expertise among young people and will be very valuable knowledge in a certain number of years; therefore anyone who doesn't know what to do with themselves but is willing to work hard can study boilers and have a very solid career in this area.