Anyone can design a waterless toilet, but every unit must be certified by the National Sanitation Foundation (NSF) to meet NSF Standard 41 – Non-Liquid Systems, tested by an ANSI-accredited third-party agency.
Only NSF-certified units are approved for use in Sonoma County, and each must also be covered under an Operational Permit (OPR) for ongoing monitoring.
A list of certified waterless toilets can be found on the NSF website.