MCU16/0079 Appendix F - Environmental Noise Imact Assessment

4.1.2    Continuous Noise Associated With Activities (E.G. Mechanical Plant)
Section 10 of the Environmental Protection (Noise) Policy 2008 provides the following guidance for
control of “background creep”1:




Based upon the measured background noise levels presented in Table 1 the “Background Creep”
criterion equates to the following levels.

    Time Varying Noise Source                                                          Noise Limit, SPL dB(A) Leq
    Day 7am to 6pm                                                                   46 (Measured L90 level 41 + 5 dB)
    Evening 6pm to 10pm                                                              46 (Measured L90 level 41 + 5 dB)
    Night-time 10pm to 7am                                                           39 (Measured L90 level 34 + 5 dB)
    Continuous Noise Source                                                            Noise Limit, SPL dB(A) L90
    Day 7am to 6pm                                                                   41 (Measured L90 level 41 + 0 dB)
    Evening 6pm to 10pm                                                              41 (Measured L90 level 41 + 0 dB)
    Night-time 10pm to 7am                                                           34 (Measured L90 level 34 + 0 dB)

                                Table 4: Noise limit criterion for “Background Creep”.




1
  “Background creep” is the effect of assessing continuous noise such as air conditioners at levels above background conditions.
The new plant will raise background noise levels, therefore, if extra plant is added, a higher noise limit results from the effect of
the existing plant. As more plant is added, the noise limits increase, thereby increasing the allowable level of noise from plant.


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