HomeMy WebLinkAboutAttach 1 Appendix B~A~ 415 3970454
CHARLES M SALTER ASSOC
a.r I es M Salter Associ
Consultants in
Acoustics
Audio/Visual
System Design
and TeJecommunications
130 Sutter Street
San Francisco
California 94164
Tel: 415 397 0442
Fax: 415 397 0454
info @ cmsalter, com
www.cmsal[er.com
Charles M Sailer, PE
David R Schwind, FAES
Anthony P Nash, PE
Eva Duesler
Thomas A SchindLer, PE
Kenneth W Graven, PE
Eric L 8raadhurst PE
John C Freytag, PE
M' 3 Toy PE
T, J Cerbe'tl
D~rand R Begault, Ph.D,
Ross A Jerozal
Philip N Sanders
Jason R Duty
Crislina L Miyar
Robed P Alvarada
Joey G D'Angela
Julia A Malork
Brian Brustad
Brenda R Yea
Eric A Yea
Troy Gimbel
Paul Langer
Timothy C McLaif)
JoshtJa M Raper
Kevin M Powell
Christopher A Pellier
Randy Waldeck
Jeff Clukey
Andrew Slanley
Peter Hoist
Elhan Sailer
EJaine Y Hs[eh
Claudia Kraehe
Jesaica Jerozal
Rebecca Cowger
Kevin Frye
B
la, en
Matra D Noordzee
Candic. Husy
Dabble Gar'cia
6 January 2004
Jennifer Lin
c/o James Tong
7077 Koll Center Parkway, Suite 120
Pleasanton, CA 94566
Subject:
Dublin Ranch, Area F North - ~ Acoustical Consulting
CSA Project No: 99-004
Dear Ms. Lin and Mr. Tong:
This letter summarizes the results of our latest enviromental noise review for 1he
proposed single-family development at Area F North. With the current land plums sent
over by MacKay & Somps indicating pad elevations and lot line setbacks from roadways,
we are able to refine our noise barrier and window recommendations. Since the Year 2020
Build-out CNELsI for Gleason Drive and Fallon Road summarized in our Traffic Noise
Study for Dublin Ranch, Areas F, G and H, dated 1 April 1999, were based on :raffle
projections that are still considered current, these noise levels are used for this ~malysis
also. The following paragraphs lists our recommendations.
Outdoors: To achieve the City of Dublin's outdoor noise goal of CNEL 60 dB in
backyards of Lots 40, 41, 85 to 87, and 90 to 99 in Neighborhood F1 located al.~ng
Gleason Drive, provide 4-foot tall noise barriers along the southern lot lines as shown in
Figure 1. To achieve CNEL 60 dB in backyards of Lots 42 to 44 in Neighborhood F2,
located north of Gleason Drive, provide 6 foot-tall noise barriers along the lot lines as
shown in Figure 2. The earthen berm that would be provided east of Neighborhood F2
would acoustically shield Fallon Road traffic noise to the nearest backyards. For your
information, noise barriers would not be required for any of Area F North if the City of
DubLin chose to apply their alternative outdoor noise goal of CNEL 65 dB.
Indoors: No sound-rated windows are required to achieve the City's indoor noJ.se standard
of CNEL 45 dB for this project. However, windows located at second floors of homes at
Community Noise Equivalent Level (CNEL)--A descriptor for the 24-hou~ A-weighted average noise level.
The CNEL concept accounts for the increased acoustical sensitivity of people to noise during the evening
and mghttime hours. Sound levels during the hours from 7 pm to 10 pm are penalized 5 dB; round levels
during the hours from 10 pm to 7 am are penalized 10 dB. A 10-dB increase in sound level i, perceived by
people to be a doubling of loudness.
Jennifer Lin and James Tong
6 January 2004
Page 2
the aforementioned 18 lots and Lots 40, 41, 45 to 48, and 85 to 90 in Neighborhood F2, as
well at both floors of homes on Lots 59, 60, 61, and 89 in Neighborhood F1 that have a
line-of-sight to travel lanes would need to be in the closed position to achieve t~te indoor
noise standard. Therefore, an alternate form of ventilation (i.e., mechanical) would need to
be provided. This aspect of the project should be reviewed by a mechanical en~neer.
This concludes our latest recommendations for the subject project. Please call Mth any
questions.
Sincerely,
CHARLES M. SALTER ASSOCIATES~ INC.
/"7
Michael D. T6.3arP'E
Principal Consultant
MD T/Ch
P: 99-O04_04.~an6MDT_Dublin Ranch, /Irea F North
Enclosure as noted
CC:
Dave Chadboume
MacKay & Somps
5142 Franklin Drive, Suite B
Pleasanton, CA 94588-3355
Peter Quady
MacKay & Somps
Fax: 925.225.0698
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