Textile Composting

Textile Composting: An Avenue for Clothing Waste Management, Mitigating Climate Change, and Regenerative Agriculture

Ericka Leigh1, Lacey Vasconcelos-Brogioli2

1Founder of Sewn Apart, Patel College of Global Sustainability Alum, USA

2Patel College of Global Sustainability, University of South Florida Alum, USA

Abstract.

The average American throws away 82 pounds (lbs.) or 37 kilograms (kgs) of clothing per year for a total of 17 billion lbs./7.7 billion kgs annually; 15% of that is donated or recycled while the other 85% is landfilled or burned, leaching toxins into the air, soil, and groundwater. A pilot project led by Ericka Leigh of Sewn Apart is generating data to explore solutions to textile waste management. Rather than landfilling fabrics or shipping them overseas, Sewn Apart in partnership with the Patel College of Global Sustainability (PCGS) at the University of South Florida (USF) started a textile composting project at Rosebud Continuum Sustainability Education Center to explore reducing textile waste by composting it instead. Textiles were composted in two methods, one used whole cotton sheets as landscape fabric, and the other method used shredded fabric pieces mixed with food scraps, shredded paper, and mulch in a compost pile. Shredded bamboo fabric decomposed the quickest in the compost heaps and the cotton landscape fabric disintegrated in three months. All research and data suggest that if scaled appropriately, unwanted textiles made of natural fibers could be composted rather than landfilled and have a net positive impact on the environment.

Keywords: textiles, composting, circular economy, regenerative agriculture, SDGs

1. Aim

As a society, we have an insatiable addiction to textiles, primarily clothing, but also bedsheets, car seats, sofas, shoes, and bags, constantly moving through a series of different fabrics. The average American throws away 82 lbs/37 kgs of clothing a year for a collective wasted 17B lbs/7.7B kgs annually; 15% of that is donated or recycled while the other 85% of unwanted garments are landfilled or burned, leaching toxins into the soil, groundwater, air, and surrounding neighborhoods, predominantly affecting low-income communities and communities of color. The answer is not to increase donations as clothing donations can do more harm than good, especially when sent overseas as secondhand American clothing markets choke out local foreign economies while also clogging their landfills. Essentially, we make our waste someone else’s problem and trash their home simultaneously.

There’s an estimated $4.5 trillion loss in value and resources for goods not reused or recycled (Stanislaus, 2019). While I don't have an exact percentage of textiles in this statistic, we know that the secondhand clothing market is valued at $28 billion (Thomas, 2020) and that roughly 15% of fabrics make it to that secondary market. Thrift stores everywhere, large and small, are overrun with clothing donations. As much as 40% of donations are sent to landfills or sold to overseas markets (Graham, personal communication, 2018).

Instead of landfilling unwanted fabrics, Sewn Apart seeks to reduce textile waste by composting it instead. This not only diverts reusable items from the waste stream but also creates soil organic carbon which pulls CO2 from the atmosphere and adds regenerative nutrients back to the Earth. With the textile composting project, we are looking for an alternative scalable solution to address our abundant clothing and fiber rejects. We believe compost is the bridge to reducing waste and restoring our topsoil, which is imperative for a healthy, sustainable planet.

The mounting issues involving textiles, fast fashion and sustainability are being addressed by the UN Sustainable Development Goals and various stakeholders in the textile industry. The UN Alliance for Sustainable Fashion was formed at the fourth UN Environmental Assembly (UNEA-4) in order to raise awareness about the impacts of the clothing supply chain and to promote circular economy solutions. There is not widespread traction on this issue yet; however, there is a growing awareness. 

1.2    Textile Composting and SDG Alignment

Composting textiles touches on a handful of the UN Sustainable Development Goals:

#9 Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation. In cities that already have municipal composting like San Francisco or Copenhagen, there is an opportunity for new partnerships and protocols to be formed that would intercept unwanted donations from thrift stores or other clothing retailers before being landfilled or shipped overseas.

#12 Responsible consumption and production. Ensuring the products we buy can be disposed of responsibly and ethically encourages a more sustainable and safer marketplace, contributing to the circular economy and cradle to cradle principles.

#13 Take urgent action to combat climate change and its impacts. By creating soil organic carbon, we’re pulling carbon out of the atmosphere and sequestering it back into the soil. According to Bossio, et al., 2020, "We show that soil carbon represents 25% of the potential for natural climate solutions," helping stabilize forests, wetlands including coastlines, and agricultural lands and grasslands.

#15 Restore terrestrial ecosystems, halt and reverse land degradation. Because compost is so nutrient-rich, it can restore damaged lands with proper application and has been used in various land restoration projects.

2. Textile Composting at Rosebud Continuum

Sewn Apart in collaboration with the Patel College of Global Sustainability (PCGS), USF GLOBE and the SDG Action Alliance aim to educate and provide alternatives to the conventional waste streams of landfill and donation. By exploring the way textiles are consumed and finding solutions for the waste generated, we aim to create a model that can scale horizontally to communities everywhere.

We were given a plot of land measuring 30 feet by 10 feet (3 meters by 10 meters) to conduct the project at Rosebud Continuum. To date, we have composted 400 lbs/181 kgs of clothes and other textiles including cotton sheets, cotton curtains, bamboo fabric, denim pants, cotton and poly-cotton blend shirts, and muslin and linen fabric. Fabrics were received from seven people and food scraps were collected from 10 households.

Methods. Textiles were composted using two different methods, in an open-air compost pile and used as landscape fabric. Decomposition varied depending on scenario.

In compost pile: We shredded the fabric and layered it in the compost with food scraps and shredded paper, and covered it with cedar mulch. Materials were cut into pieces the size of the palm of a hand. We have four different compost piles with four different types of fabric: one of cotton jersey, one of cotton linens, one of bamboo fabric, and one of mixed cotton, including some polyester-cotton blends. Poly-cotton blends consist of 5% polyester-95% cotton to 40% polyester-60% cotton. All piles consist of equal parts shredded fabric and food scraps.

All compost heaps were covered with grass clippings when available and a layer of cedar mulch to help insulate the pile aiding in the decomposition. Once every two to three weeks, compost piles were aerated by being raked out and raked back into a heap.

As landscape fabric: We lined the whole area with whole cotton sheets and covered it with two inches of cedar mulch. After three months, the cotton sheets were wholly decomposed. Other fabrics used as landscape fabric include whole cotton tee shirts, a curtain valance, one 50%-50% poly-cotton blend sheet, denim pants, and cotton sweat shorts. All of these items were also covered with two inches of much.

This project was conducted in Florida at the beginning of summer, creating favorable conditions for composting. Hot, sunny weather coupled with high humidity and weekly rains aided the compost piles in retaining moisture and encouraging the breakdown of organic materials. It is presumed that textile composting piles started in the fall or winter will take longer to decompose due to the cooler temperatures and intermittent rainfall. Some of the challenges encountered were scarcity of green matter, rodents digging in a pile, and no proper sifter to separate items not breaking down. We used traditional green matter in the compost heaps with no meat or dairy, mainly using fruits and vegetables, lots of eggshells, coffee grinds, and small paper waste and cardboard egg cartons. Brown matter included the paper waste, shredded paper, cedar mulch, and fabrics.

Results: The bamboo fabric decomposed the fastest. Some pieces are wholly deteriorated in three months, and the rest of the scraps are still in the process. The bamboo fabric contained 5% spandex; the spandex did not break down but did leave behind a thin netting material that was easy to pull out of the pile, and would be easily caught in a sifter.

Regarding the compost piles, it is evident that the integrity of all fabrics – cotton, bamboo, poly-cotton blends – is compromised. The color is fading in many cases and the materials are very easily torn by hand. Some fabrics are also starting to separate as is the case with the bamboo-spandex blend, where the bamboo has disintegrated and the spandex remains in the heap. As for the cotton piles, we have fished out polyester thread from the hem of the tee shirts. It is presumed that the cotton compost piles will need another three to six months to decompose fully.

At the time of this writing, we have composted 400 lbs/181 kgs of textiles and 650 lbs/295 kgs of food and created over 275 lbs/125 kgs of soil organic carbon. The composted clothing soil was tested and showed high levels of calcium, magnesium, and zinc. More testing needs to be done to determine carbon sequestration levels.

Discussion. Disposal of spandex remnants requires further consideration. Testing of other natural fabrics which includes wool, cashmere, silk, and Tencel, is necessary to expand the fashion circular economy. Other experiments in textile composting would include the incorporation of certain microbes to aid in the breakdown process.

It is necessary to test the soil for heavy metals, pigments, or compounds that might leach out from the dyes.

3. Conclusion

Composting textiles proves to be an innovative way to minimize waste, restore depleted soils, and create more jobs. It is proven that textiles can be composted based on this project. Previous projects support this theory, as well, including the USDA's Soil Your Undies Challenge (Soil Your Undies, 2018), research from soil scientist Oliver Knox (Knox, 2020) who participated in that challenge, and experiments from two universities (Muslin Composting Project Underway, 2015) (Staff, 2017). All studies emphatically state that YES, composting textiles as a waste management tool can be done with enough time and properly managed.

Previous studies share that compost has been used in land restoration projects (Henry & Bergeron, 2005) and pulls carbon from the atmosphere (Key Messages, 2021; Composting, 2020; Griscom et al., 2017). Increasing composting efforts in general also proves to be a promising climate solution. Since municipal composting was implemented in San Francisco, they've been able to divert 80% of their waste from landfills (Trickey, 2019). Composting more organic matter, including natural fiber textiles, could reduce landfill input by 50% (US EPA, 2013) and pull Gigatons of CO2 from the atmosphere a year (Bossio et al., 2020) while creating jobs in the process and building community. Scaled appropriately, this model can be implemented in cities everywhere, composting more waste and creating healthy soil worldwide.

Acknowledgement

Thank you to Rosebud Continuum for the plot of land and mulch. Additionally, this pilot project would not have been possible without the help from the PCGS students and faculty, USF GLOBE, and the SDG Action Alliance.

References

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Henry, C., & Bergeron, K. (2005). COMPOST USE IN FOREST LAND RESTORATION. https://archive.epa.gov/wastes/conserve/tools/greenscapes/web/pdf/compost-uw.pdf

Key messages | Global Symposium on Soil Erosion | Food and Agriculture Organization of the United Nations. (n.d.). Www.fao.org. https://www.fao.org/about/meetings/soil-erosion-symposium/key-messages/en/

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Staff. (2017). Textile Student’s Project Looks at Composting Cotton Waste From Campus Labs. North Carolina State University; Wilson College News. https://textiles.ncsu.edu/news/2017/04/textile-students-project-looks-composting-cotton-waste-campus-labs/

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Thomas, L. (2020, June 23). Resale market expected to be valued at $64 billion in 5 years, as used clothing takes over closets. CNBC. https://www.cnbc.com/2020/06/23/thredup-resale-market-expected-to-be-valued-at-64-billion-in-5-years.html

Trickey, E. (2019). San Francisco’s Quest to Make Landfills Obsolete. POLITICO. https://www.politico.com/news/magazine/2019/11/21/san-francisco-recycling-sustainability-trash-landfills-070075

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