During excess penetrant removal of colour contrast penetrant testing waste water is generated. For conventional test products the waste water must be cleaned in waste water treatment plants, for example using activated carbon.
Already in 2014, HELLING has found evidence of the penetrant NORD TEST ROT 3000 regarding the biodegradability verified by the Eurofins institute.
The Zahn-Wellens test has proven that the test product NORD TEST ROT 3000 is biodegradable, and that the waste water can be discharged usually without any treatment into the sewer system.
Please ask the local water company for official permit.
Significant costs can be reduced with respect to the waste water treatment system and operation costs.