How do I get a permit for a composting toilet?

Some terms to help you understand how many jurisdictions approve composting toilets:

  • NSF/ANSI 41 certified – NSF is a US based public health and safety organization that creates standards and tests products to see if they meet those standards. NSF Standard 41 is a standard developed in the 1970s for composting toilets it tests both the product and does an evaluation of the manufacturing facility. NSF 41 is for “non-liquid saturated treatment systems,” which means it is used to test and evaluate incinerating toilets as well as composting toilets. Composting toilets can be evaluated by several different ANSI-approved third party organizations to meet the NSF 41 standard, including CSA (the Canadian Standards Association). NSF has certified Clivus Multrum and Sun-Mar composting toilets (look in NSF’s product listing under 41). CSA has certified (look in their certified product listing under “composting toilet”) Envirolet and Blooloo. 


  • Manufactured non-NSF 41 certified – Manufacturers of composting toilets pay for their product to be tested to the NSF Standard 41. The testing can around $20,000 per product for the first year with annual renewal fees. Since NSF standards are primarily specified in regulations in the US and Canada, foreign manufacturers often do not pay for NSF certification unless they are sure they can regain the cost of the testing.



Because regulations for the installation of composting toilets vary widely across the country, consulting your local building codes and environmental health authority are good first steps. Greywater Action’s page on composting toilet codes and regulations also has good basic information on the state of composting toilet policies.

DEQ’s Fact Sheet on Composting Toilets

Oregon Department of Environmental Quality Fact Sheet: Considerations for Installing a Composting Toilet System

In Oregon, NSF 41 certified toilets have been allowed in residential homes since 1978 according to the residential plumbing code ORS 918 770-0080. Oregon has also approved the installation of manufactured non-NSF 41 certified and site built composting toilets under the 2011 Reach Code. The Reach Code additions are subject to fecal coliform and moisture content testing after their first operational period, the same testing that is required of NSF 41 certified toilets.

In Oregon, a code appeal is required to use composting toilets for commercial projects because composting toilets are not outlined in the current commercial plumbing code. For a fee the Portland’s Alternative Technology Advisory Committee (ATAC) can assist you in crafting your appeal. One hundred percent of all building code appeals that ATAC has put forward have been approved. To appeal with ATAC’s help you will need to provide evidence that the proposed technology can meet the building code, and will have a positive impact to the earth’s natural systems. In 2015 Lewis and Clark College was granted an appeal to install a NSF-41 certified composting toilet (a Clivus Multrum stand alone unit) at their campus. Read the Lewis and Clark case study about their code appeal process at the Code Innovations Database.  

Locations in Oregon with permitted composting toilets:

Info about Permitted Composting Toilet Precedents in Oregon
  • Sandy Beach campground/boatdock in Troutdale, OR
  • East Multnomah Soil and Water Conservation District Office in Portland, Or (Phoenix composting toilet installed in 2009)
  • Government Island State Recreation Area in the Columbia River northeast of Portland, Oregon (2 Phoenix composting toilets installed in 2011)





How do I make sure my compost is safe for use in my garden?

Compost from toilets should undergo fecal coliform and moisture content testing to ensure safety, the same biological testing that NSF-certified manufactured composting toilets must undergo. Testing depends on the lab, but usually costs between $35-70. Oregon State provides a useful list of soil testing facilities that serve Oregon. If the lab conducts fecal coliform testing for water they can also do it for compost. Most labs can also do a moisture test. Instead of a lab test one can also squeeze the compost to see if moisture beads up. If the compost is dripping wet, it’s too wet. If a bit of moisture beads up when it’s squeezed it probably has less than 40% moisture.