Inside the Materials Recovery Facility

The annual Doors Open event has gone virtual this year, due to the pandemic, and will run from September 26 through October 11, but will still offer interesting tours, with participating, historic buildings and organizations in Milwaukee showcasing their sites through virtual content ranging from photos to videos to 360 degree-virtual reality tours. Here is the fifth of a series on the Top 5 offerings by Doors Open: 

Of all the events that grace our city’s calendar each year, Doors Open Milwaukee is my favorite. Like a slightly O.C.D. tourist, I plan my routes both by topic and geography, in order to maximize the amount of sites I’ll see each day. This year, I went for industrial locations in Milwaukee that are not normally open to the public. One of the most eye-opening sites I encountered was the City of Milwaukee & Waukesha County Materials Recovery Facility, otherwise known as our local recycling plant. It is located in the Menomonee Valley at 1401 W. Mount Vernon Ave.

In short, a materials recovery facility (or MRF, in recycling speak) is a plant to which recyclables are trucked in for sorting by material type. Once the materials are separated, they are organized into uniformly-sized bales that can be sold to any interested buyer. On the tour, our group got to see every stage of the sorting process (while the machines weren’t running).

The Milwaukee MRF is a single-stream facility, which means that all material comes into the facility in one big mixture. To handle such a hodgepodge, the plant has some ingenious methods for separating materials. First, all of the material is dumped into a giant pile, where large pieces that would jam the equipment are removed from the mix. The remaining material is sent up a sloped conveyor belt, into a room where pickers remove certain items that aren’t recyclable, including wood and resins. Then these items drop through holes in the floor, so that they fall into piles on the ground below. The remaining items continue along the conveyor belt into the next room, where the separation process continues. Tin cans and other ferrous materials are identified with magnets, while aluminum cans are found using an eddy current. Plastics are sent through an optical scanner, which can identify the component resins in each item (differentiating each plastic as a #1, 2, 4, or 5). Once identified, a puff of air pushes each plastic in the direction of its specific type. Along the assembly line, glass is gradually broken into tiny pieces. The glass is separated from tiny pieces of paper through another puff of air. The puff is strong enough that the paper shreddings will glide forward along the conveyor belt, but weak enough that the glass pieces will fall down to a compartment below. In the end, all of the materials are sent to a machine that packs them each into uniform bales, which are secured with wire.

The bales of sorted material are sold to a wide variety of companies around the country, where the materials can be turned into new products. Metal cans are sold to steel mills and foundries to be remolded into cans and other metal products. But some of the other uses for the recyclables are less predictable. Phone books are sent to Ohio to be remade into home insulation. Some of the #1 plastic bottles get a second life in Georgia as new carpets, while a portion of the #2 plastic jugs are transformed into lawn furniture in Illinois. Large laundry baskets can be made into plastic paint buckets in Alabama, while paper cartons are sent to the Fox Valley to be turned into tissue and toweling. Glass processed at the facility tends to stay in Milwaukee, with some of it being used for road paving, and another portion going towards new bottles at the local breweries. The outcomes for the recyclables from the local MRF are nothing if not varied.

The new facility came about as a joint venture between Waukesha County and the City of Milwaukee (the Milwaukee County suburbs handle their recycling elsewhere), which operated separate materials recovery facilities until the late 2010s. Both entities were dealing with aging equipment, and dual-stream recycling was falling out of favor, because dual-stream recycling requires residents to sort material by type. In a rare show of regional solidarity, the City of Milwaukee and Waukesha County decided that a shared single-stream facility would be the most efficient and economically feasible option going forward. The city and county hired a private firm called ReCommunity to design, build, and run the regional MRF, which opened in March 2015. According to a press release from the MRF, the plant can process 35 tons of recyclables per hour, and 60,000 tons per year.

Random Tips for Recycling

• The most profitable material that the MRF sells is aluminum cans.
• The MRF accepts plastics # 1, 2, 4, and 5. Don’t send in #3, 6, or 7 plastics. It is cheaper to buy virgin materials to make #3 plastics than to buy recycled #3’s, so the MRF does not accept them.
• One of the most effective things a person can do to lessen their environmental impact is to use a reusable water bottle rather than plastic bottles. While plastic water bottles are initially recyclable, the plastic degrades over time, and eventually will wind up in a landfill.
• Small items like bottle caps fall through the system when not attached to anything larger. If you would like to recycle the cap of a plastic bottle, make sure the cap is screwed onto the bottle. If you would like to recycle the plastic cap of a paper carton, the cap must be separated from the carton (since paper will be sold separately from plastics) and somehow grouped with other plastics. Beer bottle caps or metal can lids should be placed inside of a metal can, with the top rim of the can pinched together.
• The regional MRF cannot handle plastic bags, which get trapped in their equipment. A group called Wrap Recycling Action Program (W.R.A.P.) has filled this gap by encouraging local grocery stores to collect plastic bags for recycling. To find a grocery store that accepts plastic bags for recycling, check this website.
• Surprising items that the MRF accepts include metal cooking pots and pans, bulky #2 plastics including large buckets and crates, and waxed paper drinking cartons.

And now for our tour inside the Materials Recovery Facility.

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