Virtual Materials Recycling Facility Tour

Have you ever wondered what happens to your recycling after it’s collected?  Join us on a virtual tour of our sorting facility!

When the City’s Refuse Division picks up your recycling and trash, it gets taken to a Transfer Station, where waste is transferred from the trash or recycling truck into separate semi-trucks.  Then they haul the trash to the landfill and the recycling to the Materials Recovery Facility (MRF).

Recyclables waiting to be sorted at Republic Services.

Republic Services is the MRF for the entire Saint Louis metro area (MO and IL).  They process and sort 800 TONS of recyclables every day–that’s over 1.5 million pounds!  Trucks deliver recyclables every day and they get emptied onto what is called the tipping floor.  Imagine if this is what your daily ‘to-do’ list looked like!

From the floor, the items are fed onto a conveyor belt to begin the sorting process.  Human power is the first line of defense.  Republic employs roughly 140 people and about 90 of them work on the lines.  (That’s right: recycling creates jobs!)  Workers are the first station the conveyor belt moves through.  Their job is to pull off any contamination they see like trash, food waste, plastic bags, medical/hazardous waste, hoses, ammunition, you name it. 

Workers pulling contamination off the lines at Republic Services.

That is why anything that looks like trash (e.g. recyclables in plastic bags) gets pulled off the line and put in the trash chute if it’s seen in time.  But those lines are moving quickly; they process 25 tons an hour!  So workers simply aren’t able to catch all the contamination and problematic items, like plastic bags, still slip through.

Workers cannot open bags

One reason is there simply isn’t enough time.  The conveyor belts move at high speeds and, unfortunately, there is a lot of contamination that needs to be removed.  Another reason is that not every bag has recycling in it.  Imagine slicing open a bag only to have moldy food or unknown liquids spill out.  At best, the entire conveyor belt is contaminated and must be shut down to clean it.  At worst, a worker is now covered in liquid, must leave their post to clean up and possibly be taken to a hospital (if chemicals may have been involved) to get cleared before they can return to work.  Sharps are also a hazard.  When people put needles in their recycling bin, the needles can puncture a worker’s hand through their gloves.  This type of injury requires medical testing and treatment at a hospital.

Paper being sorted at Republic Services.

After making their way through the workers, different mechanical machines sort the recyclables together by type.  Eddy currents blow the aluminum cans up, laser optical scanners sort the plastic bottles and containers by type, glass falls to the bottom and breaks and paper and cardboard continue on.  Once it is all separated, each material gets bailed together and shipped off to a manufacturer who buys them and turns them into new products!  Your recycling is not trash, it’s a valuable commodity which is why it needs to be clean.

Bales of aluminum waiting to be sold, melted down and made into new cans!


Contamination is the biggest and most costly problem facing the recycling industry today and it comes in many forms.  Recycling things you’re not sure about, but hope are recyclable, is known as ‘wishcycling’.  Those items end up being sorted improperly and can ruin an entire bale of materials because manufacturers don’t want to buy bales that are visibly contaminated like, the one pictured on the right.  For instance, because a plastic plate is flat and mimics the shape and weight of paper, it will get sorted as paper and now it contaminates that paper bale.  In addition to wishcycling, throwing items in the recycling bin that you know don’t belong, like food waste, Styrofoam or plastic bags, is another big source of contamination.

A plastic bag that managed to make it through the lines is now contaminating this paper bale.

Plastic bags are part of a category of items known at the MRF as ‘tanglers’ because they get tangled in the gears.  Gears, like the ones pictured below, are exposed and a crucial part of the sorting process.  Other tanglers include hoses, holiday lights, VHS tapes, cords and wires.  Tanglers are a big problem because they cause the MRF to shut down the lines so workers can go in and manually cut out all of the tanglers.  Between all their shifts and area facilities, our MRF loses 6.5 hours a day, primarily due to plastic bags jamming up the machines!

Workers cutting plastic bags out of the clogged gears at a MRF.

Brent Batliner is the general manager for Republic Services in St. Louis and he shared with us why contamination is such a big problem for MRFs.  “Contamination causes several issues for us.  It drives up cost by increased labor, increased investment, and increased disposal cost.  It drives down value by creating a lower grade of saleable material if it makes it through our system.  Every percentage drop in contamination will increase value, and reduce cost back to the consumer.”

That means YOU can help fight contamination!  Recycle responsibly and stick with the six items that can always be recycled: paper, flattened cardboard, plastic bottles and containers, metal food and beverage cans, glass bottles and jars and food and beverage cartons.  If it’s not on that list, it does NOT go in your Blue Bin!  To find places to donate or recycle items that do not go in your Blue Bin, visit our database:


  • Martin Raitzsch says:

    A very good description what people can/should do to minimize mistakes by recycling and it can help keep environment in better shape. As a former European “recycler” I have had learned how to recycle properly, and it work there.
    I can see you doing it equally now and it feels good to know that we are doing a very good job.

    PLEASE MAKE IT MORE PUBLIC TO ALL HOUSEHOLDS and let children in schools know how important that is to save our wonderful “Blue Planet”
    Thank you very much!!!

  • Steph van Schalkwyk says:

    Is the USA the only developed country that uses single stream recycling?
    It causes such a mess and requires so much more labour.
    In Europe, neighbours make themselves responsible for making sure the right thing goes into the right bin on the right day.
    It would we so good if we had the discipline and the lack of entitlement, to do that here.

  • Glenn May says:

    I think I’ve gotten pretty good at sticking with the 6 items. In addition I sent my food wastes to Perennial City for composting. As a result my trash can isn’t full as often and never stinks. Sometimes I can pour my trash into the trash dumpster and continue to use the same plastic bag to line my trash can. It’s a win, win.

    • Samantha Villaire says:

      That’s great! Once we start reducing the waste we send to the landfills, our trash cans and trash bags get smaller, too! Keep up the great sustainability work, Glenn!

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