Tag: ReLoop

As part of our increasing work in recycling and recovery, Project Associate Danielle Peacock and Senior Manager Anne Bedarf continue their recycling blog series, ReLoop, which will address different recycling topics, questions, and concepts. You can check out other posts from the ReLoop series here.
There are three primary ways to collect household recycling: source separation, single stream, and no separation from trash (or “all in one”), and each of these methods provides unique benefits and trade-offs. So far in the ReLoop blog series, we have covered source separated recycling and single-stream recycling. In this blog we take a closer look at “all in one” collection, also known as mixed waste processing (MWP) or using a “dirty MRF.”
MWP is a one-bin system where the consumer places all trash and recyclables in one bin with no separation. This material then proceeds to a sorting facility to glean recyclables. In our previous blog post on single-stream recycling, we discussed how a Material Recovery Facility (MRF) works. These facilities use a combination of machinery and human hands to sort.
MWP uses what is commonly called a dirty MRF because the incoming stream is household trash (also known as Municipal Solid Waste, or MSW). See this report for profiles of different types of sorting facilities, including pictures. This report also estimates that MWP facilities make up less than 5% of all MRFs in the US.
There are varying estimates of the effectiveness of MWP facilities[1]:

• Kit Strange in Issues in Environmental Science and Technology estimates that 10-30% of waste entering a MWP facility is recovered as commodity grade recyclables, with contamination contributing to this low rate. Contamination is reduced when input comes from homogenous sources like office buildings.
•  The City of Toronto studied various waste treatment and recovery systems, including dirty MRFs. They found that success relies on a clean and dry stream, and current recovery rates rest around 5–10% with a low quality output due to contamination. They ultimately chose a different course of action.
• StopWaste.Org (Alameda County, California) calculated the average recovery rate for MWP facilities in California at 19%, compared to 85% at single-stream MRFs.
• Pinellas County, FL also studied California facilities. They found a maximum recovery rate of around 30%, with a higher rate possible when co-locating with composting. It was not recommended as the primary method of recycling.
• R3 Environmental planned to co-locate a dirty-MRF with an incinerator in New Hannover County, NC. The project ultimately failed.

As with any recycling system, there are trade-offs:
Good – MWP requires no consumer participation, education, or sorting behavior. It can also be used to recover additional recyclables from the waste stream missed in recycling separation. MWP facilities can also co-locate with single-stream recycling MRFs, waste to energy, or composting facilities to maximize their impact. The quality of materials recovered through MWP is maximized if the source is homogenous, like office waste, or has organics removed prior to disposal.
Bad – The lack of consumer participation can also be seen as a negative, as there are no educational opportunities and consumers are less likely to make the connection to the impacts of their consumption habits. In addition, compared to the other methods, the potential for contamination is very high and the recovery rate is relatively low. Pre-separating organics and investing in technology can improve this process. However, these two options revert to consumer participation and require significant investment in machinery. Use of human labor exacerbates the potential for negative human health impacts on workers. Accepting all municipal solid waste into a MWP facility increases the likelihood of worker being exposed to dirty diapers, spoiled food, sharps, medical waste, and hazardous wastes. In his book Garbage Wars, author David Pellow describes such conditions for workers in a Chicago facility in the mid 1990’s, which used a combination of technology and hand sorting.
Contamination continues to be an important factor in the recycled commodities market. Contaminated materials require extra processing or are rejected outright and sent to landfills. The export market for these lower quality materials is also shrinking. Most recently, China has begun to crack down on unwashed plastic imports and contaminated paper bales.
The Grey Area – Like both of the recycling systems previously discussed in this blog series, decision makers must weigh the pros, cons, and costs of any system. What is the primary goal of the recovery system? Are you using MWP as the sole recycling system? Are you using it to glean additional recyclables from trash after single-stream separation? Are you co-locating with energy recovery or composting? How much are you willing to invest in technology versus human labor?
One East Coast city provides a particularly salient example. In this city, which will remain nameless, transparency is lacking at the local dirty MRF, and processes and recycling rates are unknown. Advertisements from both the dirty MRF and haulers falsely promote a recycling rate of 90%[2], push the dirty MRF as a superior recycling option, and confuse residents by labeling it “single-stream recycling.”  Contamination is billed as “not a problem,” though discussions with local recyclers show significant concern regarding material from this source. Many residents adopted the dirty MRF as their primary recycling option though curbside and drop-off recycling were available.  While some robust local dialogue occurred, there is still a prevailing misconception that the dirty MRF recycles 90% of all waste and is a viable recycling option.
So where does MWP fit? In my opinion, it is not appropriate as a primary recycling option. At present, the best opportunity for MWP is co-location with a landfill or waste to energy facility to provide a final sort of municipal solid waste prior to disposal. Concurrent organics source separation would greatly decrease contamination. This catches missed items and provides a last effort in areas with no recycling ethic or options. However, it should not be billed as a significant recycling option.

As part of our increasing work in recycling and recovery, Project Associate Danielle Peacock and Senior Manager Anne Bedarf continue their recycling blog series, ReLoop, which will address different recycling topics, questions, and concepts. You can check out other posts from the ReLoop series here.
There are three primary ways to collect household recycling: single stream, source separation, and no separation from trash (or “all in one”). Each of these methods poses unique benefits and trade-offs. In the last ReLoop blog, we covered single-stream recycling. This month we take a closer look at source separated recycling.
Recycling is a process in which valuable materials flow from collection to an end user, who makes the materials into new products. This flow of materials is often called the recycling “stream.” In single-stream recycling, mixed recyclable materials travel together (separately from trash) in one stream to a sorting facility, or Material Recovery Facility (MRF).
Source separated recycling is “separating materials by type at the point of discard so they can be recycled.” For example, there may be separate streams of metal, glass, paper, and plastic; or there may be one stream for paper and one for mixed containers. Source separated recycling may also be called sorted stream recycling or dual stream recycling. These terms are used synonymously and all mean that the consumer sorts their recyclables.
Items collected may still go to a MRF for further sorting. For example, North Carolina has a network of “Dual Stream MRFs,” where two or more streams of recycling are fed separately into the facility. In this example, mixed paper is one stream and mixed containers are a second.

GreenBlue’s Source Separated Recycling Bins
(Plastics, Metal, Glass, Paper)

The primary methods to collect source separated recycling are drop-off centers and curbside collection. In our office, we separate our recyclables into multiple bins, which are then taken to a local drop-off recycling center. At this drop-off, there are separate bins for each material. Our items are pre-sorted in the office, but sorting can also be done at the drop-off site if you bring a bin of mixed recyclables and hand sort them into the appropriate bins. These bins can then go directly to a buyer.
Source separated recycling can also be collected at curbside. Trucks collecting these materials have multiple chambers, one for each stream of materials. Programs may use multiple recycling bins or large carts with a center divider, creating two chambers. Materials are then dumped into the corresponding chamber. This contrasts to single-stream recycling, where the bin of mixed recyclables goes directly into a collection truck with no additional sorting.
Good – Materials from source separated recycling are generally higher in quality and can be sold at a higher price than materials collected as a single stream. There is also less potential contamination of recyclables (for example, left over liquids do not spill on paper and broken pieces of glass do not mix in with other items). Source separated recycling also does not rely as heavily on expensive sorting technology or manual labor.
Bad – Source separated recycling requires more effort by the consumer to either leave sorted items at their curb or take them to a drop-off site. In an area with a low recycling ethic, this can negatively impact participation in recycling, making collection volumes low.
The Grey Area – When it comes to recycling, many communities must make tough decisions between ease of use, quality of recyclables, and quantity of collection. Source separated requires more effort, but single stream (and all-in-one to a greater degree) results in more contamination, making a certain amount of materials unsuitable for sale and the processing of recyclables more difficult. Both programs require effective communication to consumers. Placing the wrong items in the recycling stream makes the materials less desirable, less valuable, and more difficult to manufacture into new products. Cost is another important factor in analyzing different types of recycling programs. The cost of a program is heavily dependent upon existing infrastructure, local markets for materials, and community goals.
We encourage you to explore your own recycling options, and let us know what you find!

As part of our increasing work in recycling and recovery, Project Associate Danielle Peacock and Senior Manager Anne Bedarf are debuting a new recycling blog series, ReLoop, which will address different recycling topics, questions, and concepts. Danielle kicks the series off with a primer on single stream recycling. If you have a specific recycling topic you would like covered here in the future, let us know!

There are three primary ways to collect household recycling: single stream, source separation, and no separation from trash (or “all in one”). Each of these methods poses unique benefits and trade-offs for recycling. This first installment of ReLoop tackles single stream recycling, which is quickly becoming a national trend.
Single stream recycling requires households to use two separate collection bins for their waste, one for trash and one for recycling. Residents place all of their recyclable materials in one bin, separate from their trash container.¹ On collection day, the materials are transported to a Material Recovery Facility, or MRF. The MRF will use a combination of hand sorting, sensors, magnets, and gravity to sort the materials. You can find a great animation of how a MRF works here. After sorting, the materials are baled and sold to market.
Many communities are transitioning to recycling carts that are of equal size to trash bins. This enables and encourages residents to collect more recycling than they could fit into a small tote bin or bag. Communities may even use the same trucks to collect trash and recyclables, minimizing any additional transportation or operating costs. The same truck may pick up your trash one week and recycling the next. Trucks can also be designed with dividers, so that trash goes in one section and recycling in another.
The Good: Putting all recyclable materials into one container makes recycling easier for households. Ease of use, and the prevalence of large bins, allows high collection volume. Participation in recycling is also incentivized when communities reduce trash collection to twice a month and provide increased recycling collection to compensate.
The Bad: While volume is increased, the quality of the materials that are recovered can suffer. When recyclable materials are lower in quality, they fetch a lower price at market and may be used in lower quality products. For example, if a glass jar full of sauce breaks during the recycling process, the sorting equipment may not catch the glass and the sauce will contaminate other materials, like paper. Sorting is also an imperfect science, though the technology continues to evolve.
It is important to place empty and clean materials into your bin, and follow all recycling instructions provided by your community. If you have any questions or comments about single stream recycling, leave us a comment below!