UBLIC HEARING: Director of Development ... - City of Glendale

35
4. 4. Noise
made acceptable for sound critical uses with proper design. The "normally unacceptable"
threshold at an industrial site as established by the City of Glendale, is specified as a CNEL of
75 dB. 35
Construction noise on the project site could range anywhere from 70 to 105 dBA at a
distance of 50 feet from the source, depending on the type of equipment used. Construction
noise impacts on the project site are anticipated to be less than significant, due to the lack of
sensitive land uses in the vicinity of the site. The nearest sensitive land use is a residential
neighborhood, located approximately 1,200 feet away, which due to distance and a dense array
of intervening industrial buildings acting as sound barriers would not experience any significant
noise impact due to construction actiVities.
As indicated in Section 2. of this document, Project Overview, the project site has been
active since 1958 in the operation of helicopters. The site was used by Helicopters, Inc. from
1958 to 1964, by the Los Angeles Police Department from 1964 to 1983, by the Glendale
Police Department from 1972 to 1992, and by the Burbank Police Department from 1978 to
1988. 36
A noise study analyzing historical and future helicopter noise levels associated with the
proposed project was performed by Arup Acoustics and is attached as Appendix B to this
document. A letter describing the history of helicopter operations at the project site was
prepared by Heliport Consultants and is included as Appendix B to this document. Helicopter
flight information for the years 1974 through 1992 was made available by the Los Angeles,
Glendale, and Burbank police air support units. Based on this information, past and future
noise levels generated by helicopter operations were estimated for the project site and four offsite
receptor locations. These receptor locations, depicted in Figure 5 on page 44, Noise
Monitoring· Locations" consist of single- and multi-family residential areas and represent the
noise sensitive land uses that are closest to the project site. As indicated on Figure 5, these
locations, numbered one through four, are approximately 1,200, 1,900, 1,600, and 1,900 feet
away, from the project site, respectively.
Table 7 on page 46 shows that the CNEL generated by helicopter operations at the four
receptor locations ranged from as low as 49 dB in the years 1974 through 1977 to as high as
62 dB in the years 1978 through 1983. During the entire 18 year period identified on Table
7, an average of 67 percent of these flight events (landing or take off) occurred between the
City of Glendale. General Plan. Noise Element. Figure 5. page 36.
36 Letter from Helipon Consultants. March 7. 1996. page 2.
PlaMing Consullants Research
Glrndalr Rfdevelopment Agency
Page 43
DreamWorks Animation Campus AddeoolllJJ EIR
June 1996