Model code for Compost and Urine Diverting Toilets

Download Model Codes from Recode

2017 WE-Stand Draft Document

Composting and Urine Diversion Toilet Model Code

Recode’s Composting Toilet Code Committee (see below)  created a site-built composting toilet code with options for urine diversion for IAPMO’s 2015 Green Supplement to the Uniform Plumbing Code.

The 2015 Green Supplement was the basis for WE-Stand 2017 Water Efficiency Standard, IAPMO’s released in May 2018 as a National Standard for water efficiency and sanitation. IAPMO is a plumbing and mechanical industry group whose codes have been adopted by jurisdictions worldwide.

WE Stand contains a chapter for composting and urine diverting toilets written by Recode’s Composting Toilet Code Committee (see below). Supplementary codes such as WE Stand are in the trial phase before the regular plumbing code. This new code language is a step towards normalizing composting toilets in commercial and residential buildings, but only if people use it.

In writing the code, our committee sought to create inspection points that assured authorities of the safety of site-built composting toilets, especially simple ones that creatively reuse common containers like wheelie bins and buckets. The next step is to see if the We Stand code helps people obtain permits for their composting toilets, whether site-built systems, foreign models, or other systems not certified to NSF-41. Documenting and sharing permitted installations will help move composting toilets into the Uniform Plumbing Code and beyond.

Beyond Uniform Plumbing Code jurisdictions

As an ANSI standard, the WE Stand code should be usable in both Uniform Plumbing Code and International Plumbing Code jurisdictions.

We released the Recode Model Code for Composting and Urine Diverting Toilets as a public domain document before submitting it our draft to WE Stand. While some language was moved and changed, the underlying content and requirements match. We hope our Model Code will aid in normalizing composting toilet standards and inspection points regardless of jurisdiction.


Questions regarding the Uniform Plumbing Code can be directed to the Composting Toilet Code Committee Chair Mathew Lippincott.

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Recode’s Composting Toilet Code Committee

Huge thanks to Committee Chair and Editor Mathew Lippincott and the entire working group that collaborated on this project:

Mathew Lippincott

A researcher and designer, Mathew co-founded the Public Laboratory for Open Technology and Science. There he develops environmental monitoring tools with a focus on involving and training non-technical participants in technology deployment. When not researching the history of technology, you can find him flying kites & balloons.

Laura Allen

Laura Allen is a founding member of Greywater Action and has been exploring low-tech, urban, sustainable water solutions for the past 15 years. Laura’s research and writing on composting toilets and urine reuse has been featured in the anthology Dam Nation: Dispatches from the Water Underground, and in the international journal Sustainable Sanitation Practice with her article Backyard Urine Recycling in the United States of America: An Assessment of Methods and Motivations. She has been featured in an Ask This Old House episode on greywater, and a Peak Moment TV episode on composting toilets. She leads workshops and presentations on composting toilets and greywater systems in California. Laura has a degree in Environmental Science from UC Berkeley, and a masters in education. She has lived with a waterless composting toilet in her own home for the past 10 years.

Mark Buehrer

Mark is the founder and director of 2020 ENGINEERING located in Bellingham, Washington. He is a registered professional civil engineer, author, and inventor with broad experience in engineering design, construction and project management. Mark has provided Master Planning, Engineering Design and/or Construction Management assistance on dozens of LEED, LID and other sustainable type projects in many parts of the U.S.A including the Bullitt Foundation building in Seattle.

Molly Danielsson

Molly Danielsson is researcher and content developer for Recode Oregon. Molly has conducted extensive interviews with installers, developers, and regulators in the onsite community both nationally and internationally in order to create educational materials about performance based codes for Recode. Molly creates visual explanations of technical information for companies ranging from IceStone durable surfaces to the Medical Reserve Corp to USA Today.  BA Environmental Science Oberlin College 2007. Molly worked with Mathew Lippincott and PNCA’s  Collaborative Design Program to create an emergency sanitation handbook called the Sewer Catastrophe Companion, which has been exhibited at the Center for Disease Control and approved by the Portland Bureau of Emergency Management. Molly also co-wrote the composting toilet code for the Oregon Reach Code.

Melora Golden

Melora has provided vision and project management for Recode since 2008. Before becoming an environmental activist, Melora was a social worker for 12 years. Melora Golden believes that bringing more intention and tools to group interaction will significantly increase the effectiveness of those groups. Melora has visited 37 countries learning about sustainable design and visiting intentional communities. She has attended the last two international permaculture conferences and convergences. She is active in the international permaculture community and was the lead organizer of the second and third Women’s Permaculture Gatherings.  She is a seventeen-year resident of Portland OR, she is dedicated to her wonderful city and to the sustainable evolution of the world.

Colleen Mitchell

Colleen is a civil engineer with five years experience, specializing in water and wastewater systems design, technical report writing, and LID site design. Her educational background includes a B.S. Degree in Civil Engineering with a focus in water resources including courses in “Green Engineering”, LEED Rating System and Low Impact Development (LID) site design. Colleen is a LEED Accredited Professional (LEED AP) and a Certified Erosion and Sediment Control Lead (CESCL). Colleen has completed the LID Technical Training Program certified by Washington State University and the Puget Sound Partnership. Colleen uses stormwater modeling on small and large scale projects using LID techniques to meet and exceed jurisdictional requirements.

Kim Nace

Kim Nace is a co-founder and administrative director of the Rich Earth Institute. She holds an M.A. in International Administration from World Learning and an M.A. in Educational Leadership from Keene State College. She was a Peace Corps volunteer in Botswana, has coordinated educational research funded by the MacArthur Foundation, and also served as an Elementary School Principal in rural Vermont and in Chennai, India. She has been passionate about sustainable sanitation alternatives ever since creating an educational video about composing toilets for her 1989 master’s thesis project. Kim and her family use a urine diverting composting toilet.

Glenn Nelson

Glenn Nelson founded Advanced Composting Systems in the mid-1980s creating the Phoenix composting toilet. Prior to that he was a licensed manufacturer of Clivus toilets (one of two in the U.S.) and played a key role in improving the Clivus design. Through working on the Clivus design, he gained a great deal of insight into the workings of composting toilets then, with the Phoenix, he designed a very different product.

Abe Noe-Hayes

Abraham Noe-Hays has been working with dry sanitation systems since 1990. He is the research director at the Rich Earth Institute, where he oversees the Urine Nutrient Reclamation Project, the nation’s first community scale urine collection and recycling program. The Institute develops and disseminates methods and technologies for urine recycling, and is conducting USDA and EPA funded studies to evaluate the fertilizer value of source-separated urine. Abraham also operates Full Circle Compost Consulting, founded in 2001, providing complete design, manufacture, and maintenance services to individual and institutional owners of dry toilet systems. He is the eco-sanitation expert for Sustainable Harvest International, and has helped initiate urine-diversion projects in Nicaragua, Honduras, Belize, and Panama. He holds a B.A. in Human Ecology with concentrations in agroecology and compost science from the College of the Atlantic.

David Omick

David Omick does sustainable system design and consulting with individuals and organizations in the U.S. and Mexico. in the early 2000’s, in conjunction with BorderLinks, a Tucson-based NGO, he designed a large composting toilet facility at Casa Misericordia in Nogales, Sonora to serve border education delegations from the United In 2005, as the representative of a composting toilet stakeholder group, he contributed rule language to the composting toilet section of the Aquifer Protection Rules administered by the Arizona Department of Since 2011, he has worked closely with the Watershed Management Group (WMG), a Tucson-based NGO. In that capacity, he has led composting toilet workshops for WMG. He has also been instrumental in facilitating a 2-year composting toilet pilot project led by WMG and funded by a grant from the Environmental Protection Agency. This project has involved 23 site-built composting toilets of two designs, one of which is his. The project has been in collaboration with the Arizona Department of Environmental Quality and the University of Arizona’s School of Microbiology and School of Anthropology. He serves on the advisory committee for this pilot project.

John Scarpulla

John Scarpulla is a member of the Urban Watershed Management Program at the San Francisco Public Utilities Commission, where he specializes in green infrastructure, non-potable reuse systems, and ecological sanitation. Before coming to the San Francisco Public Utilities Commission, he worked at the Sierra Club teaching integrated water resource management strategies to planners, elected officials, and developers in San Mateo and Santa Clara counties. He also has worked in the commercial construction sector as a project manager for mechanical and plumbing contractors. John received his master’s degree in Environmental Planning from San Jose State University.

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