Any opening in the well seal or casing wall not less than one-quarter inch in diameter through which unobstructed access to the inside of the casing can be obtained for measuring water levels. Inspection ports shall be threaded openings temporarily sealed with a removable watertight plug.
INSPECTION PORT
Meaning of INSPECTION PORT in English
Environmental engineering English vocabulary. Английский словарь экологического инжиниринга. 2012