Waterless toilets can be installed in homes, accessory dwelling units (ADUs), and commercial buildings, but they must be used with a septic system — not instead of one.
Even when a waterless toilet is installed, wastewater from sinks, showers, and laundry must still be directed to an approved septic system.
If adding an ADU or new building increases wastewater flow, the property owner must show that the existing septic system can handle the additional use, or modify it accordingly. In some cases, this can be offset by a bedroom swap (reducing bedrooms in the main house).
Waterless toilets are installed indoors, so septic system setback requirements do not apply to the toilet itself.