All plumbing work must be performed either by an owner or by a journeyman plumber holding a valid certificate of competency from the State of Oregon, or a registered and indentured apprentice.  All journeyman plumbers while engaged in plumbing work must carry with them their Oregon State Certificate of Competency.  All apprentice plumbers must carry with them their apprentice registration cards and must produce them at the request of the Plumbing Inspector.  It is the duty of the Plumbing Inspector to require the journeyman plumber and apprentice plumber to show their registration card. 
In the event anyone is performing plumbing work in violation of the above regulations, a report relative to such person will be sent by Portland Permitting & Development Plumbing Section to the Oregon Building Codes Division, Plumbing Division.