The following Product Service Codes (PSCs) are commonly associated with NAICS 221320, Sewage Treatment Facilities

PSC S222 Housekeeping—Waste Treatment/Storage

Services
Federal Category 4.4: Facilities & Construction Facility Related Services

PSC H346 Inspection—Water Purification and Sewage Treatment Equipment

Services

PSC S216 Housekeeping—Facilities Operations Support

Services