Glass Recycling The US: Challenges, & How To Increase Rates

The guide below is a case study on glass recycling in the United States.

We outline some of the main challenges with recycling glass in the US, and potential solutions for increasing glass recycling rates.

Summary – Glass Recycling In The United States

Recycling Rates In US vs Other Countries

Compared to up to a 90% glass recycling rate in some other countries, only about one third of glass is recycled in the US (as a whole) annually

Some places in the US like San Francisco have higher than average overall recycling rate, but these places are the exception right now

Potential Reasons For Low Glass Recycling Rates In The US

Some of the major reasons might include but aren’t limited to:

Limited availability of affordable glass cullet of an acceptable quality, along with inefficiencies in processing cullet

Varying cullet specifications

Contamination of glass, and challenges sorting for glass with commercial value from single stream waste collection

Size of the US, & the distance between different glass recycling parties

A lack of knowledge is not the cause – the US has the knowledge to achieve higher recycling rates

Other Potential Reasons For Low Glass Recycling Rates In The US

Some of the other general reasons for the current glass recycling rates in the US might include:

The overall economics of making and recycling glass

Differences with other countries relating to the government policy around glass recycling and waste management

Education & awareness

Potential Solutions To Increasing Glass Recycling Rates

Some of the main solutions might include:

Improving overall cullet processing, and making processing more efficient

Standardising cullet specifications where possible

Implementing multi-stream recycling in place of single stream recycling, reducing the contamination of glass, and improving the sorting of glass

Addressing distance between different parties along the glass recycling chain

Other Potential Solutions To Increasing Glass Recycling Rates

There may be a range of other potential solutions, which we’ve listed in the guide below

On wider scale, changing the way we use glass, and the use of alternative materials (other than glass) could be further options.

We’ve also previously written about potential solutions for improving overall recycling rates and systems in this guide. Some of these solution may also help with glass recycling.

Potential Benefits Of Recycling More Glass

Glass cullet is a granular material made by crushing bottles and jars usually collected from recycling programs

cen.acs.org indicates that glass cullet benefits glassmakers, the environment, and consumers in several different ways (which cen.acs.org outlines in their guide)

We outline some potential additional benefits of recycling glass in this guide

Tradeoffs With Recycling More Glass, & Choosing Different Waste Management Strategies

It’s worth noting that all waste management decisions come with tradeoffs.

Making changes to glass recycling comes with it’s own set of pros and cons over the short and long term, and changes need to be compared to the option of dumping or incinerating the glass waste.

Multi-stream recycling for example might be more expensive than single stream recycling

We’ve also previously outlined the potential pros and cons of recycling in general in this guide

A Note On The Resources Mentioned In This Guide

In the guide below, we extrapolate on, paraphrase, or use direct quotes from an existing article by cen.acs.org.

You can view the full article on glass recycling in the US cen.acs.org

We also add some of our own feedback and commentary throughout the guide below

The article listed by recyclingtoday.com is also worth a read for an explanation of how glass recycling myths can be debunked, and the capabilities of certain glass recycling equipment and facilities

Recycling Rate Of Glass In The US vs Recycling Rates In Other Places

Glass Recycling Rate In The US Nationally

[Currently, only about one third of the glass disposed of in the US gets recycled annually]

Glass Recycling Rate By US State (Or City)

Note though that specific States and cities in the US may have a recycling rate for glass that is higher (and also lower) than the national average i.e. the glass recycling rate might differ between States

As one example, although the recycling rate for glass specifically as a material isn’t listed, San Francisco currently diverts 80% of their total waste from landfill to recycling and composting.

Glass Recycling Rate In Other Countries

[In comparison to the US’ glass recycling rate …] There is a 90% recycling rate [for glass] in Switzerland, Germany, and other European countries

Reasons For Current Glass Recycling Rates In The US (Challenges For Glass Recycling)

Some of the challenges for glass recycling in the US, and some of the reasons for the current national glass recycling rates might include:

– Limited Availability Of Affordable Glass Cullet Of An Acceptable Quality (& Inefficiencies In Processing Cullet)

… glassmakers are limited by what recycled material is available to them at a manageable cost

[This is especially the case for clean, furnace-ready cullet produced from single stream processing]

[Clean, furnace ready cullet is also processed] inefficiently [in the US] compared with [other countries like] Europe

– Varying Cullet Specifications

Another reason is that costs of recovering cullet are impacted by cullet specifications that vary between manufacturers [because different suppliers need to meet the needs of different manufacturers]

– Contamination Of Glass, & Challenges Sorting For Glass With Commercial Value From Single Stream Waste Collection

… US municipalities manage residential recycling primarily via single-stream curbside collection

… non recyclables [are incorrectly] thrown in the recycling bin … [and the result is glass gets contaminated from mixing with this other waste]

[Not only is glass contamination a problem, but, having multiple types of waste in recycling bins makes it more difficult and time consuming to sort through the waste to find material that has commercial value and that] manufacturers will pay for

[Roughly 40% of glass put in single stream recycling gets recycled compared to about 90% of glass put into multi stream recycling … and this mainly comes down to] the difference in the quality of glass from the two streams

[Multi stream recycling] is simpler on the processing end [than single stream recycling because glass is separated by consumers from other recyclables into glass only bins]

[A con to multi stream recycling is] a high level of consumer education [is usually required] and [it] is considerably more expensive than single-stream collection.

[But, a couple of pros of multi stream recycling are that] the glass is much cleaner than what comes out of the single-stream supply, [and] glass can go straight to cullet processors [and skip sorting facilities]

Single stream recycling is ultimately an inherently inefficient and expensive recycling method. But most municipalities in the US stick with single stream because the collection costs are lower than those with multi-stream systems

– Size Of The US, & The Distance Between Different Glass Recycling Parties

The size of the US [can be an issue because of the] distance between a materials recovery facility and a cullet supplier, or a cullet supplier and a buyer …

… [the distance tends] to be greater [than in European nations] … [and this presents an economic issue because transport is costly]

* A Lack Of Knowledge Of How To Recycle Is Not The Reason

A lack of knowledge is not the reason glass recycling rates are what they are

The US has the knowledge achieve higher glass recycling rates

Other Potential Reasons For The Current US Glass Recycling Rates

– The Overall Economics Of Making & Recycling Glass

The production of glass and recycling glass both have economic challenges to consider.

A few examples outlined above are affordability of cullet, and, the costs of single stream vs multi stream recycling.

We’ve previously written about the economic feasibility of recycling in general in this guide.

– Differences With Other Countries Relating To The Government Policy Around Waste Management & Recycling Glass

Some other countries may have policy in place that supports recycling financially in a different way than what different States in the US do.

– Education & Awareness

Like for example the education and awareness around sorting and disposing of glass.

How The US Might Increase Glass Recycling Rates

Some of the potential solutions might include:

– Improving Cullet Processing Overall, & Making Processing More Efficient

The processing of cullet ideally results in clean, affordable cullet that is available to recyclers and manufacturers when they need it

Ideally, it’s also processed in an efficient way.

– Standardising Cullet Specifications Where Possible

Ideally, manufacturers and suppliers are able to work together to find practical ways to standardise cullet specifications where possible (instead of having varying specifications)

– Implementing Multi-stream Recycling In Place Of Single Stream Recycling, Reducing The Contamination Of Glass, & Improving The Sorting Of Glass

This would involve the implementation of multi stream recycling that separates glass from other materials (both recyclable and non recyclable), and also reduces glass contamination, as well as helping recyclers have a less time consuming way of sorting commercially valuable glass (that manufacturers will accept) from less valuable glass

Cleaner glass may even go straight to cullet processors without being sorted

Multi stream recycling would replace single stream recycling in some instances

Multi stream recycling can ultimately lead to ‘large quantities of high-quality cullet that are essential to further increase the recycled content in products’

There may be a tradeoff to multi stream recycling though – it will likely be more expensive in the form of higher collection and handling/hauling fees, taxes, or subsidies. Most municipalities might be reluctant to do this. Cost is often a barrier to upgrading from single stream

Multi stream programs can also require more consumer education

– Addressing Distance Between Different Parties Along The Glass Recycling Chain

Transporting glass waste and cullet between waste pickup locations, material recovery facilities, cullet suppliers, and buyers needs to be addressed.

Centralized or more local processing centers may be a solution i.e. local and state based glass recycling systems and facilities might help (recycling programs, cullet processors, suppliers, manufacturers, etc.)

If economic feasibility can be established, the distance to transport glass across existing distances may be supported by public funding.