Noise Abatement Ordinance
(NAO)

The en­force­ment au­thor­it­ies shall in­spect the new or mod­i­fied in­stall­a­tion with­in one year of its be­ing put in­to ser­vice to check wheth­er the emis­sion lim­it­a­tion and sound­proof­ing meas­ures ordered have been taken. In the event of any doubt, they carry out tests to as­sess the ef­fect­ive­ness of the meas­ures.