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Home My WebLink AboutCT 2017-0005; GRAND WEST; NOISE IMPACT ANALYSIS; 2017-10-11-------- ----... -----... ----------------- Prepared by: /IQ®&.~ Hans D. Giroux Senior Analyst Giroux & Associates 1800 E. Garry A venue #205 Santa Ana, Calif. 92705 Project No.: Pl 7-043 N NOISE IMPACT ANALYSIS 972 and 988 GRAND A VENUE CARLSBAD, CALIFORNIA NOV 21 2017 c:r ·/ ._ P! i Prepared for: CCI Attn: Terry Mathew 160 Industrial St., #200 San Marcos, CA, 92078 Date: October 11, 2017 ------------... ------------------------.. INTRODUCTION The City of Carlsbad has adopted noise guidelines for new development in the City. The City's guidelines, as articulated in the "City of Carlsbad Noise Guidelines Manual" (September 1995), focus on residential noise protection. The City's guidelines, however, also incorporate noise standards for non-residential use. Noise compliance requirements vary with land use sensitivity, and differentiate between whether a given use is more of a noise generator, or more of a receptor. City noise requirements include the following: Exterior Guidelines: Designed to insure that proposed land uses are built within an environment where exterior noise levels are compatible with the noise sensitivity of the proposed use. The siting guidelines are incorporated in a noise land use matrix entitled "Land Use Compatibility for Community Noise Environments." The City standard for exterior residential space is 60 dB CNEL except in close proximity to McClellan-Palomar Airport where the standard is relaxed by 5 dB CNEL. Interior Guidelines: Designed to insure that structural noise reduction achieves an acceptable interior noise level compatible with the intended use. Interiors of commercial uses are considered less noise sensitive than school, churches or similar non-residential uses, but less noise-sensitive than industrial operations. The interior noise standard for new residential development is 45 dB CNEL. If exterior fa;:ade noise levels exceed the ability for unmitigated structural noise attenuation to meet this standard, upgraded structural features (better windows, thicker insulation, supplemental ventilation, etc.) may be required Non-Land-Use Issues: Noise from animals, loud gatherings, construction, motor vehicle testing, etc. are regulated by ordinance. They are not discussed in this noise report. The City's Noise Guidelines Manual requires consideration of construction activity noise under certain conditions. In the absence of residential uses in very close proximity to the proposed project site, and with elevated background levels due to nearby freeway, train track and power plant sources, construction noise is not an issue for this project. AIRCRAFT NOISE The City's guidelines also address aircraft noise exposure relative to McClellan-Palomar Airport. The project site is well outside the airport noise "footprint." Airport noise is not considered a constraint for the proposed project. NOISE DESCRIPTORS Noise is generally defined as unwanted or annoying sound that is typically associated with human activity and which interferes with or disrupts normal activities. Although exposure to high noise levels has been demonstrated to cause hearing loss, the principal human response to environmental noise is annoyance. The response of individuals to similar noise events is diverse and influenced by the type of noise, the perceived importance of the noise and its appropriateness in the setting, C:IUsers\Terry Mathew\AppData\Local\Microsoft\WindowslINetCache\Content. Outlook\TVLB3D 19\F 17-043 Carlsbad Noise V l .docx -------------------... -----------.. ---... -- the time of day, the type of activity during which the noise occurs, and the sensitivity of the individual hearing the sound. Airborne sound is a rapid fluctuation of air pressure above and below atmospheric pressure. Sound levels are expressed as a ratio of the ambient sound pressure level compared to the sound faintly detectable by a young person with good auditory acuity. Because the human ear can hear over a very wide range ofloudness, this ratio is expressed as a logarithm in system of units called decibels ( dB). Most of the sounds we hear in the environment do not consist of a single frequency, but rather a broad band of frequencies differing in sound level. The intensities of each frequency add to generate the sound we hear. The method commonly used to quantify environmental sounds consists of determining all of the frequencies of a sound and weighting them according to the average human sensitivity in each portion of the noise spectrum. This is called "A-weighting", and the decibel level measured is called the A-weighted sound level ( or dBA). Although the A-weighted sound level may adequately indicate the level of environmental noise at any instant in time, community noise levels vary continuously. Most environmental noise includes a mixture of noise from distant sources that create a relatively steady background noise in which no particular source is identifiable. A single descriptor called the Leq ( equivalent sound level) is normally used to describe average noise levels of a stated time period. Leq is the 'equivalent' constant sound level that would have to be produced by a given source to equal the energy content of the fluctuating level measured. Another sound descriptor known as the Community Noise Equivalent Level ( or CNEL) is defined as the sensitivity-weighted average sound level for a 24-hour day. It is calculated by adding a 5-decibel penalty to sound levels in the evening (7:00 p.m. to 10:00 p.m.), and a IO-decibel penalty to sound levels in the night (10:00 p.m. to 7:00 a.m.) to compensate for the increased sensitivity to environmental noise during "quiet hours." Land use compatibility is generally expressed using the CNEL descriptor, particularly for residential uses exposed to noise on a 24-hour basis. CNEL-based standards are generally applied to noise from on-road vehicles, trains, or aircraft because local jurisdictions are preempted from directly-regulating noise generation from such sources. Since the City cannot regulate the noise generation, it controls the land use exposed to such noise. LEQ-based standards are typically applied to sources that are amenable to direct control. Such standards are commonly included in municipal or development codes. For uses not occupied for 24 hours, the noisiest single hour of the day is often more relevant than the 24-hour weighted average (i.e., CNEL). The City of Carlsbad interior noise standards for non-residential uses are therefore based upon the peak hour LEQ. Residential uses are typically not noise generators that would be affected by code requirements. BASELINE NOISE LEVELS The perceived possible noise constraint upon the proposed project is the proximity of 1-5 traffic. However, the freeway is over 500 feet from the project site and several intervening buildings uch C:\Users\Terry Mathew\AppData\L0<:al\Microsoft\Windows\INetCache\Content. Outlook\TVLB3Dl 9\P 17-043 Carlsbad Noise V l .doc,c 2 ---------------... --------------------- as the Extended Stay Hotel and Denny's Restaurant create only a narrow unobstructed field of view. See Figure 1 On-site noise measurements were made on July 31, 2017 on the project site. An additional measurement was made at the second story of the Motel 6 with a similar partial view of I-5. To compare upstairs and downstairs readings the freeway traffic was clearly audible, but not at levels that were perceived as intrusive. Recorded mid-afternoon levels were as follows: Location Leq Lmax Lmin L50 Site-Downstairs 60 73 54 57 Motel 6 2nd storv 61 73 61 58 One story higher did not measurably increase traffic noise. Caltrans guidance suggests that weighted 24-hour CNELs are typically 2-3 dB higher than mid-afternoon Leq readings. These readings suggest that noise levels in the proposed private yards and private patios may marginally exceed the most stringent City of Carlsbad residential standard by 2-3 dB CNEL. It is anticipated that a perimeter privacy wall will be constructed along the property line on all sites except the driveway. The noise attenuation from a solid barrier that is 6-feet above grade is typically around 6 dB. The City's outdoor recreational noise standard would be met with such a barrier with a substantial margin of safety. Peak building fa9ade noise levels of 64 dB CNEL would require 19 dB of structural attenuation to achieve the City's 45 dB CNEL interior noise standard. With typical code-compliant construction, the following hierarchy of noise reduction is achieved in practice: Partially open windows -12 dB Closed single pane and supplemental ventilation -20 dB Low-end dual pane and supplemental ventilation -25 dB High-end dual pane and supplemental ventilation High-end dual pane and supplemental ventilation and added insulation -30 dB -35 dB Even closed single pane windows and supplemental ventilation would achieve the 45 dB CNEL requirement. However, the current CalGreen code almost always mandates use of dual-paned windows. This energy conservation requirement will insure that noise control standards are readily met so long as a supply of supplemental fresh air is provided. CONCLUSION Freeway proximity is not a noise constraint with the adoption of only minor noise control measures. C:\Users\Terry Mathew\AppData\Local\Mkrosoft\Windows\INetCache\Content. Outlook\TVLBJD 19\P 17-043 Carlsbad Noise V l .docx 3 FIGRUE l: PROJECT SITE LOCATION C.\Usen\Terry Mathew\AppOata\Loca~MierosoR\Windows\lNetC1che\Content.Outlook\TVLBJO 19\P 17-043 Carlsbad Noise VI docx 4 FIGURE 2 -SUMMARY OF NOISE GUIDELINES -CITY OF CARLSBAD Noise Guidelines Manual CITY OF CARLSBAD FIGURE -Ill LAND USE COMPATIBIUlY FOR COMMUNITY NOISE ENVIRONMENTS MATRIX Land U.e Category. R11ldentlel • (all) Single Family, Duplex, Mobllehome, Multi-Family, etc. Tranolent Lodging • Mot•I, Hotel School, Library, Church. Hotpitel, Nurting Home Auditorium. Concert Hall, A"'11hi1h•at•r Sport• Aron.a, Outdoor Sp•ctetor Spotto PlaY11round, Neighborhood Park Golf Couroo, Riding Steble. Watet Recr•atlon, Cemetery Office Building. eu,;,,.,.. Commercial Planned Industrial end Profe11lonal Ge-el lnduotriat, Manufacturing, Utifitle1, Agriauhut• Community Noise Exposure CNEL, dB 55 60 65 70 75 Summary vi 80 INTERPRETATION: Normally A_,,.., .. ~HH~ Sp•cified land ute II H tl1factory. bNad up<>n tM Hl~tian that any buildlnge Involved ar• of normal conv1ndonlll conatruction, without any epeclel noiH lneulatlon requiremento. Conftonaly Acoeptable Naw oonetNotlon or d•velopment 1hould b• undetta.,, only ett11 • d•tellad analvei• of the noi•• ,eduction ,.qu;,ementa 11 med• end needed nol•• inllUledon luturoa included Int.,. dulgn. Conwndon.al conllNCtlon, but with clooed window• and fr•oll lir tupply •veteme ot air condllloning will normellV auffice. No,INly °"-tllli. Naw ooMINOtion or development thoulcl gantrelly ba dlacouragad. II ntw oonatn,ction o, dewlopmont doH procoad, • H~~ ... detailed 1nelyei1 of Illa nolH reduction r•quiramanta mutt ba made tnd needed noiN lnoulation fHrur11 lnciucled In t.,. daalgn. L-U.. Die-, .. ~ New conatruc•on or dewlopmant lhcK,kf oa-•v not .,. undartak•n. NOff: McCle .. n ,.,_ Airport NoiA la regulated by the Airport Compre.,.,.elw Land U.a Plan ICLUPI. Sea tha CLUP for alrport nolH compatibility guldalin ... C.\Usen\Tcrry MalhcwlAppOata\Local\Miaosoft\Windows\JNctCache\Conlcnt Outlook\TVLBJDl9\PI 7-043 Carlsbad Noise VI docx 5 FIGURE 3 -SITE PLAN I I I I I I I GRANO AVENUE SHEET SP.2 Slff Pl.AN SCAl.f. 1· • 10'4' ----~ 0 10 20 JO nu 140&.001 J ca.09 2011 \\CCI-DISKST A TION\cc~CCI\Active Projects\Dejong-Carlsbad\6 ) Envuonmenral Repons\PI 7-043 Carlsbad Noise VJ .docx