Blog / Our Work | Environmental Stewardship

40 Years of Seattle’s Master Composter Sustainability Stewards Program 

July 17, 2026

This year, we are celebrating a big milestone: 40 years of Seattle’s Master Composter / Sustainability Stewards  (MC/SS) program. What started as a small idea from a handful of volunteers has grown into a program that has shaped how our city handles waste for four decades.

Some of our earliest Master Composter volunteers, gathered at the demonstration site that helped start it all.
A Compost Hotline volunteer at her desk, fielding calls in the program’s very first years.

Where It All Began 

In the mid-1980s, a few volunteers at Seattle Tilth, now Tilth Alliance, saw that the city would benefit from a small but mighty change in how residents handle their yard waste. At the time, landfills in Seattle were filling and closing frequently. The city needed a new approach to handling waste. 

Seattle Tilth offered to teach residents how to make compost out of their yard waste to use in their own gardens and improve soil quality. This would not only improve backyard gardens but also keep yard waste out of landfills and prevent them from filling up too fast. 

The Department of Engineering, now Seattle Public Utilities (SPU), accepted their proposal and in 1986, a group of about 30 volunteers learned how to compost and went out to teach Seattle residents. They traveled to all of Seattle’s different neighborhoods, building compost piles and installing worm bins. This was the beginning of the world’s first Master Composter program. 

Other cities, including Portland, OR, and New York City, looked at Seattle and adopted similar volunteer-based programs to build awareness around solid waste reduction. Many relied on teaching materials from Seattle Tilth.

The very first Compost Hotline, ready to answer Seattle’s gardening questions back in the 1980s.

Growing Beyond Composting 

Today, forty years later, this SPU-Tilth Alliance partnership is still going strong. Composting is still a major part of the volunteers’ curriculum, but the scope has grown to include other solid waste topics, such as: 

  • Reducing contamination 
  • Keeping food waste out of the landfill 
  • Reducing single-use plastic waste 

By founding the Master Composter program, these grassroots visionaries from the ’80s set the stage for three programs: the compost hotline they started became today’s popular Garden Hotline, the manure composting they began at Woodland Park Zoo is still creating wonderful Zoo Doo compost, and the MC/SS program continues recruiting volunteers from all neighborhoods and communities of Seattle, keeping it a true Seattle affair. 

Forty years later, our volunteers are still showing up in Seattle neighborhoods to teach and connect.
A Master Composter Sustainability Steward helps neighbors sort their waste right, one event at a time.

A Legacy Worth Celebrating 

With the growth and changes Seattle has experienced over the past 40 years, the local culture of resource conservation and waste-free (or at least low-waste) living has only gotten stronger. We are proud that the MC/SS program has been a significant part of this cultural shift. 

Reingard Rieger, MC/SS Program Manager