Master Composter/Sustainability Stewards

MC/SS Training

Interested in learning more about compost and preventing waste, and then teaching others? Become a Master Composter/Sustainability Steward!

Seattle residents are invited to apply to participate in the Master Composter/Sustainability Stewards course – a volunteer training program with a community outreach component.

Each Master Composter/Sustainability Steward participates in 30 hours of classroom learning (combined online and hands on learning) followed by 35 hours of volunteer outreach, which could include projects such as helping reduce waste at community events, giving composting classes at schools and civic associations, helping community gardens set up a compost system and teaching Seattle residents about waste prevention at in-person and online events.

The training course covers the following topics:

  • preventing waste
  • improving soil health and building soil life
  • understanding the small-scale composting process
  • using finished compost
  • sorting your compostable and recyclable waste
  • managing stormwater and protecting water quality
  • teaching others about composting and resource conservation practices

Class Dates and Times

The training is an in-depth educational experience with online Zoom sessions and hands-on training at each of our demonstration gardens.

6 Wednesdays (7-9 p.m.)

  • March 13, 20 and 27
  • April 3, 10 and 17

5 Saturdays (10 a.m.-3 p.m)

  • March 23 and 30
  • April 6, 13 and 20

Training Location


Community outreach is an essential component of the MC/SS program and a powerful form of environmental action! Following your MC/SS training, you will become part of a select team of Seattle residents empowered to share what you have learned with friends, neighbors and the community at large. We’ll make sure you have the support you need to be successful at teaching others.


  • Residency. Only Seattle residents are eligible. Live outside of Seattle? Find out about our Soil and Water Stewardship training offered in King County.
  • Vaccination. Vaccination for COVID-19 is highly recommended, but not required for participation in the program.

We are no longer accepting applications for 2024.


Find out more about the Master Composter/Sustainability Stewards program or contact us at or (206) 633-0097.

This program is co-managed by Tilth Alliance and Seattle Public Utilities.