100.18 CLASSES OF DISCHARGE PERMIT.
Discharge permit classifications shall be as follows:
1.   Class A Permit – Issued to users discharging 25,000 gallons per day or more of process wastewater (excludes sanitary, non-contact cooling, and boiler blowdown).
2.   Class B Permit – Issued to users discharging less than 25,000 gpd of process wastewater.