There are also test methods for plants that treat all domestic wastewater (small sewage treatment plants). If the plants pass, these tests allow the re-use of treated black water.
The effluent from qualified plants can be used, for example, to flush toilets or irrigate gardens.
The test methods offered for domestic small sewage treatment plants are as follows:
Full American test methods for domestic small wastewater treatment plants for water re-use with numerous possibilities for end use.
Standard for performance and approval testing of small wastewater treatment plants in Australia and New Zealand. A restricted re-use of treated wastewater is possible outdoors.