Turning Tucson Green: UA Student-Run Composting Program Partners With City
Compost Cats, a UA student-run organization, has partnered with the city of Tucson to reduce food waste in area landfills, improve local air quality, address climate change and help improve food safety.

By Shelley Littin, University Communications
March 4, 2014


Madeline Ryder, Compost Cats member and UA senior double majoring in natural resources and environmental studies, operates a tractor at San Xavier Co-op Farm as she turns one of the windrows of compost.
Madeline Ryder, Compost Cats member and UA senior double majoring in natural resources and environmental studies, operates a tractor at San Xavier Co-op Farm as she turns one of the windrows of compost. (Photo: Braelyn Jane Smith)

A single person can't make a difference in the world? The 14 University of Arizona undergraduate and graduate students in Compost Cats don’t believe that.

From a humble beginning as a student-run composting program for restaurants in the UA Student Union Memorial Center, the organization – under the umbrella of the Associated Students of the University of Arizona – has grown to serve a number of Tucson businesses and the greater Tucson community.

And now it has partnered with the city of Tucson.

The intergovernmental agreement was written by Compost Cats project director and UA Arid Lands Resource Sciences doctoral candidate Chet Phillips and City of Tucson Environmental Manager Francis LaSala.  The Tucson City Council approved the agreement in January and Mayor Jonathan Rothschild signed it in February. The agreement went into effect on Feb. 24.

“It’s amazing that this is happening now,” said Madeline Ryder, a UA senior double majoring in natural resources and environmental studies and a member of Compost Cats. “This agreement is something we’ve worked hard to achieve and will enable us to serve a much larger portion of the Tucson community.”

According to the agreement, the city will provide a central food scrap station for Compost Cats, as well as transportation of compost to the San Xavier Co-op Farm, which allocates some of its fields for Compost Cats in return for 20 percent of the compost produced.

The city also will provide Compost Cats with manure from herbivores at Reid Park Zoo and all landscaping waste from the maintenance of city parks.

“It’s going to be an order of magnitude larger than what we already collect,” Ryder said.

In just two years, Compost Cats has saved over 1.5 million pounds of food waste from being dumped into landfills by collecting from the campus and Tucson businesses every day. The uneaten scraps are turned into valuable organic compost that is given back to the Tucson community for agriculture and residential gardening, and donated to Tucson schools for gardening projects.

Compost Cats’ dedication to the community and the environment was recently recognized with the Arizona Recycling Coalition’s 2013 Recycler of the Year Award.

The group is also working to become a financially self-sustaining organization. The UA Green Fund has supported it so far. Phillips and five undergraduate staff members have written a five-year business plan that provides a map to eventual economic sustainability through composting services and compost sales.

Compost Cats is collaborating with two groups of students in the UA’s Eller College of Management for help with its business plan. Assistance has also come from Todd Millay, assistant director of Arizona Student Unions, who independently approached the students and offered to help them with the details of writing a formal business plan.

The group expects to have compost available for sale to the general public from its website in the early fall.

“All of the nutrients that are in food waste and green waste are still in the compost even after the waste is broken down,” Ryder said. “So if you add the compost to soil, plants can take up those nutrients again, which helps them to grow. It’s recycling at its best.”

Compost is especially beneficial for agriculture and gardening in Arizona’s soils, which are often lacking in the nutrients and water that compost can provide.

“Adding compost means the soil can store water longer,” Phillips said. “And we will need that even more in the face of climate change.”

Ryder, who is graduating in December, hopes to continue working with local businesses and nonprofits to help solve environmental and food security issues in the Tucson area. 

“At the end of my work shift at Compost Cats I feel like I’ve contributed and I’ve done something good for more than just myself,” she said. “It’s a very holistic approach toward making Tucson better and making the world better.”


Resources for the media


Chet Phillips

Compost Cats Project Director



Madeline Ryder

Compost Cats member



UANews Contact:

Shelley Littin