Why is zero discharge defined as “no discharge of process wastewater pollutants”?
Section 301 of the Clean Water Act prohibits the discharge of “any pollutant” except if the discharge of such pollutant is in compliance with a permit. Because it is impossible to achieve an analytical detection of “zero” for a pollutant, facilities are allowed to show compliance with zero discharge if each process wastewater pollutant (e.g., the specific pesticide active ingredient) is not analytically detected in the effluent. Another way to show zero discharge is to show no flow of process wastewater from the facility.
