The Big Picture
PCR Credit: Minimize Bale/Output Contamination Rate
(1-3 Points, Reciprocal)
Credit Summary
The intent of this credit is to mitigate post-sorting contamination or residue rates for the successful recirculation of recovered materials. Local governments and municipalities are expected to use a Visual Inspection or Counts of Contamination methodology to ensure the achievement of specified post-sorting contamination/residue rates.
Impact Summary
Contamination is one of the biggest push backs in the recycling industry. As it continues to grow, more people are encouraged to get involved, but it is not unusual that these people are not going through the proper steps to ensure that their waste is being recycled. This credit will help decrease the rate of which recyclable materials are sent to landfills.
Submittal Summary
Mixed waste MRFs must allow outhrows of 90% of paper, 90% metal, less than 10% metal, 10% PET & HDPE and less than 120% of other plastics. Single stream MRFs must allow outhrows of 80% of paper, 80% metal, less than 7% metal, 5% PET & HDPE and less than 80% of other plastics. Dual stream MRFs must allow outhrows of 60% of paper, 70% metal, less than 6% metal, 4% PET & HDPE and less than 70% of other plastics. These percentages decrease as higher tiers (2 and 3) are achieved.
Case Study and Benefits
As seen below, there are numerous examples of the success rate of anti-contamination systems. Allows for these programs and systems to be implemented would dispense great results regarding contamination rate as well as diversion rate.
Other Resources
Referenced Standards and Definitions
SUPPORTING MATERIALS
Intent and Requirements
Intent
To mitigate post-sorting contamination or residue rates for the successful recirculation of recovered materials.
Local Government and Industry Requirements
Demonstrate that material recovery facilities (MRFs) operated by the Local Government or Company, or operated by companies contracted by the Local Government or Company, or operated by companies subcontracted by franchise haulers, achieve the following post-sorting contamination/residue (bale quality) rates using a Visual Inspection or Counts of Contamination methodology, as well as following relevant quality and grading guidelines and material content prohibitions of the current ISRI Scrap Specifications Circular:
- Utilize contamination/residue rate calculation methodology in the SWEEP + Certification Manual.
- Material grading of inbound material
- Inbound volume metric collection (for calculation)
- Sorting on tipping floor
- Metering drums and conveyor speeds
- Film removal (vacuum)
- Manual sorting (pick line)
- Density sorting technology (ballistic separators, conventional disc screening, etc.)
- 2-D vs. 3-D sort
- Eddy Current (Aluminum)
- Magnets (Ferrous and other metals)
- Optical sorting (glass by colors, plastics by types, etc.)
- Sorted stream metrics collection
- Residual metrics collection
Why We Care
Recycling is a $6.2 billion market in the United States, but it is being slowly bottlenecked by problems like contamination. Recycling is considered contaminated when a certain percentage of non-recyclable material is found within its batch. The current average recycling contamination rate is 25 percent, so 1 in 4 items that we attempt to recycle are actually sent to the landfill due to contamination. Contamination also leads to lost revenue for recycling plants. Nearly 1000 recycling plants in California alone were closed between 2016 and 2018 due to increased contamination rates.
Improving recycling rates, by reducing contamination, is necessary to decrease the tonnage of annual waste added to landfills. According to the EPA, of the 267.8 million tons of municipal solid waste generated by Americans in 2017, only 94.2 million tons were recycled or composted. Minimizing the contamination rate will, therefore, reduce landfill waste, increase recycling revenues, and bolster the circular economy.
How to Meet the Requirements
Local governments and industries must demonstrate that material recovery facilities (MRFs) operated by the Local Government or Company, or operated by companies contracted by the Local Government or Company, or operated by companies subcontracted by franchise haulers, achieve the following post-sorting contamination/residue (bale quality) rates using a Visual Inspection or Counts of Contamination methodology, as well as following relevant quality and grading guidelines and material content prohibitions of the current ISRI Scrap Specifications Circular.
Mixed Waste MRFs
| Paper/Paperboard < 10 Percent Moisture | Metal | “MRF Glass” | Plastic Bale Contamination | |
| Tier 1: (1 point) | Outhrows + Prohibited: 90 percent of maximum allowed for each grade | 90 percent of maximum allowed for each grade | Non-glass residue & Fines < 10 percent | – PET & HDPE bottles: 10 percent – Other Plastics: < 120 percent of recommended maximum contamination for each grade |
| Tier 2: (+1 point) | 70 percent of maximum | 70 percent of maximum | < 7 percent | – PET & HDPE bottles: 7 percent – Other Plastics: < 100 percent of recommended maximum contamination |
Tier 3: (+1 point) | 50 percent of maximum | 50 percent of maximum | < 4 percent | – PET & HDPE bottles: 5 percent – Other Plastics: < 80 percent of recommended maximum contamination |
Single Stream MRFs
| Paper/Paperboard < 10 Percent Moisture | Metal | “MRF Glass” | Plastic Bale Contamination | |
| Tier 1: (1 point) | Outhrows + Prohibited: 80 percent of maximum allowed for each grade | 80 percent of maximum allowed for each grade | Non-glass residue & Fines < 7 percent | – PET & HDPE bottles: 5 percent – Other Plastics: < 80 percent of recommended maximum contamination |
| Tier 2: (+1 point) | 60 percent of maximum | 60 percent of maximum | < 5 percent | – PET & HDPE bottles: 4 percent – Other Plastics: < 60 percent of recommended maximum contamination |
Tier 3: (+1 point) | 40 percent of maximum | 40 percent of maximum | < 3 percent | – PET & HDPE bottles: 3 percent – Other Plastics: < 40 percent of recommended maximum contamination |
Dual Stream MRFs
| Paper/Paperboard < 10 Percent Moisture | Metal | “MRF Glass” | Plastic Bale Contamination | |
| Tier 1: (1 point) | Outhrows + Prohibited: 60 percent of maximum allowed for each grade | 70 percent of maximum allowed for each grade | Non-glass residue & Fines < 6 percent | – PET & HDPE bottles: 4 percent – Other Plastics: < 70 percent of recommended maximum contamination |
| Tier 2: (+1 point) | 50 percent of maximum | 50 percent of maximum | < 4 percent | – PET & HDPE bottles: 3 percent – Other Plastics: < 50 percent of recommended maximum contamination |
Tier 3: (+1 point) | 30 percent of maximum | 30 percent of maximum | < 2 percent | – PET & HDPE bottles: 2 percent – Other Plastics: < 30 percent of recommended maximum contamination |
Required Documentation
Case Studies & In-Depth Information
AMP Robotics is developing robots for sorting recycling in order to improve the efficiency, accuracy, and speed of the process. 100 of the robots are now operational across 40 facilities in the United States. Each robot costs approximately $300,000. These robots not only sort recycling, they also flatten it to ensure compact shipping. Robotics is a growing industry, with revenue for AMP doubling annually.
Bezner Waste Management Solutions
Bezner has created a 2D/3D sorting facility that can output 1.9 tonnes of 3D waste and 3.5 tonnes of 2D waste an hour. The 3D material is transported elsewhere for the separation of ferrous and non-ferrous material, while the 2D material is sorted into SRF and RDF material. The sorted material is then baled and film wrapped for transportation to a processing facility. This system suggests potential for middle-men sorting facilities to streamline the recycling process and reduce contamination.
Referenced Standards
The previous information references the contamination/residue rate calculation methodology in the SWEEP + Certification Manual and in the How to Meet the Requirements section of this chapter.
Definitions
Bale
PRM Waste Systems Definition: Baling is a process that compresses material into a block (bale) which is secured by plastic or wire strapping. The process reduces the volume of the material which:
- Reduces loose waste on site
- Reduces transportation/waste disposal costs
- Turns waste into a revenue generating product
- Ballistic Separators
MSW Management
MSW Management Definition: The elliptical ballistic separator is designed for the need to separate two or more fractions having different physical characteristics and coming from a continuous stream of wastes from municipal single-stream or a dirty MRF. A series of parallel paddles applies a strong shaking to all of the waste to achieve separation before conveying the various material types to intended destinations.
Conventional Disc Screening
Recycling Product News Definition: The disc screen is a simple piece of equipment that is ideal for screening woody biomass. It consists of a series of driven shaft assemblies mounted in a frame. Each rotor shaft assembly has profiled discs mounted at regular spacings. The discs from one shaft interleaf with those on the adjacent shafts, creating open areas between the discs and the shafts.
Counts of Contamination
Eddy Current
Walker Magnet Definition: Eddy current separation is based on the use of a magnetic rotor with alternating polarity, spinning rapidly inside a non-metallic drum driven by a conveyor belt. As non-ferrous metals pass over the drum, the alternating magnetic field creates eddy currents in the non-ferrous metal particles repelling the material away from the conveyor. While other materials drop off at the end of the conveyor, the non-ferrous metals are propelled forward over a splitter for separation.
HDPE
SWANA Definition: High-Density Polyethylene, a plastic used to make a variety of products including milk jugs and landfill liners. HDPE containers are often identified by the number “2” inside the recycling arrows stamped on the container.
ISRI Scrap Specifications Circular
ISRI Definition: The Scrap Specifications Circular provides guidelines for buying and selling a variety of processed scrap commodities, including ferrous, nonferrous, paper, plastics, electronics, rubber, and glass.
Metering Drums
Environmental Expert Definition: Metering drum feeders provide a constant even feed rate into your sorting system.
PET
SWANA Definition: Acronym for Polyethylene Terephthalate: plastic commonly used to make containers such as soft drink bottles. PET containers are often identified by the number “1” inside the recycling arrows stamped on the container.
Residue
WM Definition: Trash, or “residue,” contaminates recyclable materials, turning the whole bin into trash.
Visual Inspection
Inspectioneering Definition: Visual Inspection, or Visual Testing (VT), is the oldest and most basic method of inspection. It is the process of looking over a piece of equipment using the naked eye to look for flaws. It requires no equipment except the naked eye of a trained inspector.