Independent Study Proposal

The Future of Sustainable Sanitation, Agriculture, and Energy: Humanure Toilets and Biogas Digesters

Mirella Kades

Primary Content Advisor

Leyf Starling

Driving Questions

  • How can humanure toilets and biogas digesters be used as a sustainable sanitation, agriculture, and energy solution?
  • How can we generalize this system to achieve several of the United Nations’ 17 Sustainable Development Goals listed below?
    • #2 Zero Hunger
    • #3 Good Health and Well-Being
    • #6 Clean Water and Sanitation
    • #7 Affordable and Clean Energy
    • #9 Industry, Innovation and Infrastructure
    • #11 Sustainable Cities and Communities
    • #12 Responsible Consumption and Production
    • #13 Climate Action
    • #15 Life on Land

Preliminary Resources and Activities

  • I have been fascinated by and researching humanure toilets and biogas digesters for many years
    • I am interested in how combining the use of humanure toilets with biogas digesters can create a sustainable and innovative system
      • Throughout my research I have found no systems that combine the use of humanure toilets and biogas digesters
  • I recently did a deep dive on this topic in my chemistry class as a passion project resulting in an infomercial promoting the system in podcast form (linked below)


  • Research
    • Review previous research
    • Do additional research as needed
  • Design
    • Working through engineering design process
      • Using what I learned in STEAM by Design, Intro to Engineering, and DARC SIDE
  • Prototype
    • Testing variables such as function and easy of use
      • Ability to transport toilet contents
        • Need to develop system for transport
      • User interface
        • Industry innovation and applying universal design principles
  • Build
  • Use & test
    • Testing easy of use
    • Testing how many usable products of the system are produced and the amount produced (biogas, compost, liquid fertilizer, etc.)
    • Testing success criteria


  • First semester of senior year (2021-2022 school year) with the intention of extending the independent study to the second semester

Mechanism for Showing Progress

  • Engineering notebook
    • With audio clips, video, etc.
    • OneNote Notebook

Expected Final Products 

  • Humanure toilet 
  • Biogas digester
  • Demonstration of how to use the toilet and digester
  • Demonstration of cooking with the biogas produced by the digester


I have been planning this independent study since the end of my freshman year. Humanure toilets and biogas digesters have been a fascination of mine since middle school, and I have spent many hours exploring them. I first learned about these systems through my other fascination, tiny houses and sustainable living. I am extremely excited to be pursuing this project and would greatly appreciate any support. 

Thank you for your time and consideration!

Jack Linger Explorer Grant

This independent study is supported by a Jack Linger Explorer Grant. Thank you to the Linger family for believing in my project!