Appendix G: Noise Modeling - PDF Free Download

Heritage Oaks Subdivison - Draft EIR Appendix G: Noise Modeling Michael Brandman Associates H:\Client (PN-JN)\2137\21370012\DEIR2\21370012_App Dividers.doc

N OISE I MPACT A NALYSIS FOR H ERITAGE O AKS S UBDIVISION PREPARED FOR: PACIFIC MUNICIPAL CONSULTANTS 585 CANNERY ROW, SUITE 304 MONTEREY, CA 93940 PREPARED BY: 1374 57 TH STREET SACRAMENTO, CA 95819 CONTACT: KURT LEGLEITER TEL/FAX: 916.456.7006 SEPTEMBER 7, 2006

NOISE INTRODUCTION This section includes a summary of applicable regulations, a description of ambient noise conditions, and an analysis of potential noise impacts of the proposed project. Mitigation measures are recommended, as necessary, to reduce significant noise impacts. EXISTING SETTING ACOUSTIC FUNDAMENTALS Noise is generally defined as sound that is loud, disagreeable, or unexpected. Sound, as described in more detail below, is mechanical energy transmitted in the form of a wave because of a disturbance or vibration. Amplitude Amplitude is the difference between ambient air pressure and the peak pressure of the sound wave. Amplitude is measured in decibels (db) on a logarithmic scale. For example, a 65 db source of sound, such as a truck, when joined by another 65 db source results in a sound amplitude of 68 db, not 130 db (i.e., doubling the source strength increases the sound pressure by 3 db). Amplitude is interpreted by the ear as corresponding to different degrees of loudness. Laboratory measurements correlate a 10 db increase in amplitude with a perceived doubling of loudness and establish a 3 db change in amplitude as the minimum audible difference perceptible to the average person. Frequency Frequency is the number of fluctuations of the pressure wave per second. The unit of frequency is the Hertz (Hz). One Hz equals one cycle per second. The human ear is not equally sensitive to sound of different frequencies. Sound waves below 16 Hz or above 20,000 Hz cannot be heard at all, and the ear is more sensitive to sound in the higher portion of this range than in the lower. To approximate this sensitivity, environmental sound is usually measured in A-weighted decibels (dba). On this scale, the normal range of human hearing extends from about 10 dba to about 140 dba. Characteristics of Sound Propagation and Attenuation Noise can be generated by a number of sources, including mobile sources, such as automobiles, trucks and airplanes, and stationary sources, such as construction sites, machinery, and industrial operations. Noise generated by mobile sources typically attenuates at a rate between 3.0 to 4.5 dba per doubling of distance. The rate depends on the ground surface and the number or type of objects between the noise source and the receiver. For mobile transportation sources, such as highways, hard and flat surfaces, such as concrete or asphalt, have an attenuation rate of 3.0 dba per doubling of distance. Soft surfaces, such as uneven or vegetated terrain, have an attenuation rate of about 4.5 dba per doubling of distance from the source. Noise generated by stationary sources typically attenuates at a rate of approximately 6.0 to 7.5 dba per doubling of distance from the source. Sound levels can be reduced by placing barriers between the noise source and the receiver. In general, barriers contribute to decreasing noise levels only when the structure breaks the "line of sight" between the source and the receiver. Buildings, concrete walls, and berms can all act as effective noise barriers. Wooden fences or broad areas of dense foliage can also reduce noise, but are less effective than solid barriers. Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 1 September 7, 2006

NOISE DESCRIPTORS The selection of a proper noise descriptor for a specific source is dependent upon the spatial and temporal distribution, duration, and fluctuation of the noise. The noise descriptors most often encountered when dealing with traffic, community, and environmental noise are defined below: L max (Maximum Noise Level): The maximum instantaneous noise level during a specific period of time. L min (Minimum Noise Level): The minimum instantaneous noise level during a specific period of time. L eq (Energy Equivalent Noise Level): The energy-mean (average) noise level is typically used to represent average-hourly noise levels when evaluating environmental noise. The instantaneous noise levels during a specific period of time in dba are converted to relative energy values. From the sum of the relative energy values, an average energy value (in dba) is calculated. L dn (Day-Night Noise Level): The 24-hour L eq with a 10 dba penalty for noise events that occur during the noise-sensitive hours between 10:00 p.m. and 7:00 a.m. In other words, 10 dba is added to noise events that occur in the nighttime hours to account for increases sensitivity to noise during these hours. CNEL (Community Noise Equivalent Level): The CNEL is similar to the L dn described above, but with an additional 5 dba penalty added to noise events that occur between the hours of 7:00 p.m. to 10:00 p.m. The calculated CNEL is typically approximately 0.5 dba higher than the calculated L dn. SEL (Single Event Noise Level): The SEL describes a receiver s cumulative noise exposure from a single noise event, which is defined as an acoustical event of short duration and involves a change in sound pressure above some reference value. HUMAN RESPONSE TO NOISE The human response to environmental noise is subjective and varies considerably from individual to individual. Noise in the community has often been cited as a health problem, not in terms of actual physiological damage, such as hearing impairment, but in terms of inhibiting general well-being and contributing to undue stress and annoyance. The health effects of noise in the community arise from interference with human activities, including sleep, speech, recreation, and tasks that demand concentration or coordination. Hearing loss can occur at the highest noise intensity levels. When community noise interferes with human activities or contributes to stress, public annoyance with the noise source increases. The acceptability of noise and the threat to public well-being are the basis for land use planning policies preventing exposure to excessive community noise levels. Unfortunately, there is no completely satisfactory way to measure the subjective effects of noise or of the corresponding reactions of annoyance and dissatisfaction. This is primarily because of the wide variation in individual thresholds of annoyance and habituation to noise over differing individual experiences with noise. Thus, an important way of determining a person s subjective reaction to a new noise is the comparison of it to the existing environment to which one has adapted: the so-called ambient environment. In general, the more a new noise exceeds the previously existing ambient noise level, the less acceptable the new noise will be judged. Regarding increases in A-weighted noise levels, knowledge of the following relationships will be helpful in understanding this analysis: Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 2 September 7, 2006

INDOORS A-Weighted Decibels Perceived Loudness Relative to 60 dba OUTDOORS Threshold of Pain 140 x256 Deafening 130 x128 Military Jet Takeoff with Afterburner (at 50 feet) Rock Band Inside Subway Train, New York 120 x64 Uncomfortably Loud 110 x32 100 x16 Jet Takeoff at 200 Feet 747-100 Takeoff (4 Miles From Start of Roll) Power Lawnmower (at 50 Feet) Ambulance Siren (at 100 Feet) Noisy Cocktail Bar 90 x8 Jet Aircraft Cabin, at Cruise Shouting (at 3 Feet) 80 x4 Noisy Restaurant Vacuum Cleaner at 3 Feet 70 x2 Large Business Office Very Loud Moderately Loud Normal Conversation (at 3 Feet) 60 x1 727-200 Takeoff (4 Miles From Start of Roll) Diesel Truck, 40 mph (at 50 Feet) Automobile, 65 mph (at 50 Feet) Busy Street (at 50 Feet) 757-200 Takeoff (4 Miles From Start of Roll) Automobile, 30 mph (at 50 Feet) Cessna 172 Landing (3,300 Feet From Rwy End) Quiet Office Moderately Quite 50 x1/2 Quiet Library Concert Hall, Background 40 x1/4 Very Quiet 30 x1/8 Quiet Urban Area, Nighttime Quiet Suburban Area, Nighttime Quiet Rural Area, Nighttime Recording Studio 20 x1/16 Barely Audible 10 x1/32 Leaves Rustling 0 Threshold of Hearing x1/64 Sources: California Department of Transportation, January 2002, California Airport Land Use Planning Handbook; M. David Egan, McGraw Hill, 1972, Concepts in Architectural Acoustics; and U.S. Department of Housing and Urban Development, Office of Community Planning and Development, The Noise Guidebook. TYPICAL NOISE LEVELS EXHIBIT 1 Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 3 September 7, 2006

Except in carefully controlled laboratory experiments, a change of 1 db cannot be perceived by humans. Outside of the laboratory, a 3-dB change is considered a just-perceivable difference. A change in level of at least 5 db is required before any noticeable change in community response would be expected. An increase of 5 db is typically considered substantial. A 10-dB change is subjectively heard as an approximate doubling in loudness and would almost certainly cause an adverse change in community response. EXISTING NOISE ENVIRONMENT NOISE-SENSITIVE LAND USES Noise-sensitive land uses generally include those uses where exposure to noise would result in adverse effects, as well as uses where quiet is an essential element of their intended purpose. Residential dwellings are of primary concern because of the potential for increased and prolonged exposure of individuals to both interior and exterior noise levels. Other noise-sensitive land uses include hospitals, convalescent facilities, parks, hotels, churches, libraries, and other uses where low interior noise levels are essential. Noise-sensitive land uses located near the project site consist primarily of rural residential dwellings. nearest residences are generally located east of and adjacent to the project site, along Rea Avenue. The AMBIENT NOISE SURVEY An ambient noise survey was conducted on July 20, 2006 to document the existing noise environment at various locations within the project area. Short-term (i.e., 10-minute) noise level measurements were taken along the eastern and western boundaries of the project site. Measurements were conducted in accordance with the American National Standards Institute (ANSI) acoustical standards using a Larson Davis model 820 sound-level meter positioned at a height of approximately 4.5 feet. Ambient noise measurement locations and corresponding measured values (i.e., L eq, L max, and L min ) are depicted in Exhibit 2. Based on the monitoring conducted, daytime average-hourly noise levels in the project vicinity range from approximately 36 dba L eq near the eastern boundary to approximately 75 dba L eq along the western boundary, adjacent to San Juan Road. The dominant noise source contributing to onsite ambient noise levels was vehicle traffic on area roadways, primarily San Juan Road located along the western boundary of the project site. REGULATORY SETTING REGULATORY BACKGROUND Many governments have established noise standards and guidelines to protect citizens from potential hearing damage and various other adverse physiological and social effects associated with noise. The applicable standards and guidelines are discussed below. State of California The California Department of Health, Office of Noise Control, in Guidelines for the Preparation and Content of Noise Elements of the General Plan (February 1976), provided guidance for the acceptability of designated land uses within specific CNEL contours. Residential uses are normally unacceptable in areas exceeding 70 dba CNEL and conditionally acceptable within 60 to 70 dba CNEL. Commercial/ professional office buildings Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 4 September 7, 2006

36.4 30.7 50.1 75.4 47.4 87.2 Measured Noise Levels Leq Lmin Lmax Average-Hourly Equivalent Noise Level Minimum Noise Level Maximum Noise Level Image Source: GLS 2003 AMBIENT NOISE LEVELS EXHIBIT 2 Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 5 September 7, 2006

and businesses are normally acceptable in areas up to 70 dba CNEL and normally unacceptable in areas exceeding 75 dba CNEL. Between 67 and 77 dba CNEL, commercial uses are conditionally acceptable, depending on the noise insulation features and the noise reduction requirements. Title 24 of the California Code of Regulations establishes standards governing interior noise levels that apply to all new multifamily residential units in California. These standards require that acoustical studies be performed prior to construction at building locations where the existing CNEL exceeds 60 dba. Such acoustical studies are required to establish mitigation measures that will limit maximum CNEL levels to 45 dba in any inhabitable room. Although there are no generally applicable interior noise standards pertinent to all uses, many communities in California have adopted a CNEL of 45 as an upper limit for interior noise in residential dwellings. County of Monterey Monterey County s exterior noise-exposure standards are based on parameters established by the California Department of Health, Office of Noise Control and summarized in Table 1. Based on these standards, noise levels of 60 db CNEL or less at various noise-sensitive receptor locations, including single- and multi-family residences, schools, hospitals, churches, and nursing homes are considered normally acceptable and noise levels of 60 to 70 dba CNEL are considered conditionally acceptable with the incorporation of noise insulation and mitigation features (County of Monterey 1993). In addition, the Monterey County Noise Control Ordinance prohibits the operation of any device within 2,500 feet of any occupied residential dwelling which produces a noise level exceeding 85 dba at a distance of 50 feet from the source (County of Monterey 1988). THRESHOLDS OF SIGNIFICANCE The following significance thresholds used for the assessment of noise-related impacts are based on the California Environmental Quality Act (CEQA) Guidelines and County of Monterey noise standards. Short-term Exposure of Noise-Sensitive Receptors to Stationary-Source Noise. Short-term construction noise impacts would be considered significant if construction activities were to exceed applicable exterior and interior noise standards adopted by the County of Monterey. The County s Noise Code currently limits noise from mechanical sources to a maximum of 85 dba at 50 feet, when operated within 2,500 feet of an occupied dwelling unit. Long-term Exposure of Noise-Sensitive Receptors to Stationary-Source Noise. Long-term stationary-source noise impacts would be considered significant if the proposed project would exceed the County s noise-control standard or result in a substantial increase in ambient noise levels at nearby noisesensitive land uses. For purposes of this analysis, a substantial increase is defined as an increase of 5 dba in areas where ambient noise levels are less than 60 dba CNEL; an increase of 3 dba where ambient noise levels range from 60 to 65 dba CNEL; and an increase of 1.5 dba where ambient noise levels exceed 65 dba CNEL. Exposure of Noise-Sensitive Receptors to Traffic Noise. Long-term transportation noise impacts would be considered significant if the proposed project would result in a substantial increase in ambient noise levels that exceed the County s noise-control standards for transportation noise sources (i.e., 60 dba CNEL/L dn [Table 1]). For purposes of this analysis, a substantial increase is defined as an increase of 5 dba in areas where ambient noise levels are less than 60 dba CNEL; an increase of 3 dba where ambient noise levels range from 60 to 65 dba CNEL; and an increase of 1.5 dba where ambient noise levels exceed 65 dba CNEL. Contribution to Cumulative Noise Levels. Implementation of the proposed project would be considered significant if the proposed project would result in a substantial contribution to projected Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 6 September 7, 2006

future cumulative noise levels at either existing or proposed noise-sensitive receptors that would exceed applicable County noise criteria for land use compatibility (Table 1). Table 1 County of Monterey Land Use Compatibility for Exterior Community Noise Noise Ranges (CNEL/Ldn) Land Use Category I II III IV Passively used open spaces 50 50-55 55-70 70+ Auditoriums, concert halls, amphitheaters 45-50 50-65 65-70 70+ Residential low density single family, duplex, 50-55 55-70 70-75 75+ mobile homes Residential multi-family 50-60 60-70 70-75 75+ Transient lodging motels, hotels 50-60 60-70 70-80 80+ Schools, libraries, churches, hospitals, nursing 50-60 60-70 70-80 80+ homes Actively used open spaces playgrounds, 50-67 --- 67-73 73+ neighborhood parks Golf courses, riding stables, water recreation, 50-70 --- 70-80 80+ cemeteries Office buildings, business commercial and 50-67 67-75 75+ --- professional Industrial, manufacturing, utilities, agriculture 50-70 70-75 75+ --- Noise Range I Normally Acceptable: Specified land use is satisfactory, based upon the assumption that any buildings involved are of normal conventional construction, without any special noise insulation requirements. Noise Range II Conditionally Acceptable: New construction or development should be undertaken only after a detailed analysis of the noise reduction requirements is made and needed noise insulation features included in the design. Conventional construction, but with closed windows and fresh air supply systems or air conditioning will normally suffice. Noise Range III Normally Unacceptable: New construction or development should generally be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirements must be made and needed noise insulation features included in the design. Noise Range IV Clearly Unacceptable: New construction or development should generally not be undertaken. Source: Monterey County, 1988. METHODOLOGY Short-term noise impacts were evaluated based on typical noise levels associated with construction equipment, derived from existing environmental documentation. Predicted areas of potential impact were calculated assuming an average noise attenuation rate of 6 dba per doubling of distance from the source. Long-term noise impacts were evaluated based on predicted near-term and future cumulative traffic noise levels, with and without implementation of the proposed project. Traffic noise levels were predicted using the FHWA roadway noise prediction model (FHWA-RD-77-108) based on data obtained from the traffic analysis prepared for this project. To ensure a conservative analysis, predicted noise levels assume no natural or man-made shielding (e.g., vegetation, berms, walls, buildings). Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 7 September 7, 2006

IMPACTS AND MITIGATION MEASURES IMPACT 1 Short-term Increases in Construction Noise. The proposed project could result in constructionrelated noise that would exceed applicable County noise standards at nearby noise-sensitive land uses. This impact is considered significant. With mitigation this impact would be considered lessthan-significant. Construction noise typically occurs intermittently and varies depending upon the nature or phase (e.g., demolition/land clearing, grading and excavation, erection) of construction. Noise generated by construction equipment, including earth movers, material handlers, and portable generators, can reach high levels. Typical noise levels for individual pieces of construction equipment are summarized in Table 2. As depicted, individual equipment noise levels (in dba) typically range from the mid-70 s to the upper 80 s at 50 feet (FTA 2006). Typical operating cycles may involve 2 minutes of full power, followed by 3 or 4 minutes at lower settings. Depending on the activities performed and equipment usage requirements, combined averagehourly noise levels at construction sites typically range from approximately 65 to 89 dba L eq at 50 feet (EPA 1971). Table 2 Typical Construction Equipment Noise Levels Sources: FTA 2006 Type of Equipment Typical Noise Level (dba) at 50 feet Air Compressor 81 Backhoe 80 Compactor 82 Concrete Mixer 85 Concrete Pump 82 Concrete Vibrator 76 Crane, Mobile 83 Dozer 85 Generator 81 Grader 85 Jack Hammer 88 Loader 85 Paver 89 Roller 74 Saw 76 Truck 88 Noise-sensitive land uses in the vicinity of the proposed project site consist primarily of rural residential dwellings, the nearest of which are generally located along the eastern boundary of the project site, along Rea Avenue. Assuming a maximum construction noise level of 89 dba L eq and an average attenuation rate of 6 dba per doubling of distance from the source, construction activities occurring within approximately 1,500 Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 8 September 7, 2006

feet of noise-sensitive receptors could reach levels of approximately 60 dba L eq. Based on typical noise levels associated with construction equipment (refer to Table 2), construction-generated noise levels could potentially exceed the County s noise standard of 85 dba. In addition, construction activities occurring during the more noise-sensitive nighttime hours may result in increased levels of annoyance and potential sleep disruption to occupants of nearby residential dwellings. Construction-generated noise would, therefore, be considered to result in a potentially significant short-term noise impact to nearby noise-sensitive land uses. Mitigation Measure 1: Short-term Increases in Construction Noise Noise-generating construction operations shall be limited to the hours between 7 a.m. to 6 p.m. Monday through Friday and between 8 a.m. to 5 p.m. on Saturdays. Construction activities shall be prohibited on Sundays. Construction equipment and equipment staging areas shall be located at the furthest distance possible from nearby noise-sensitive land uses. Stationary equipment, such as power generators and compressors, located within 500 feet of nearby existing residential dwellings shall be shielded from direct line-of-sight of the residence by use of engine shrouds or portable barriers. The location of equipment staging areas shall be shown on all improvement and grading plans. Construction equipment shall be properly maintained and equipped with noise-reduction intake and exhaust mufflers and engine shrouds, in accordance with manufacturers recommendations. Equipment engine shrouds shall be closed during equipment operation. When not in use, motorized construction equipment shall not be left idling. Significance After Mitigation Implementation of the above mitigation measures would reduce short-term noise impacts to nearby residential land uses to a less-than-significant level. IMPACT 2 Increased Exposure of Noise-Sensitive Receptors to Stationary-Source Noise. The proposed project would not result in exposure of nearby existing or proposed residential land uses to noise levels that could exceed applicable County noise standards. This impact would be considered less than significant. No mitigation is required. The proposed project includes planned development of a total of approximately 31 residential use lots ranging in size from approximately 1 to 16 acres. The proposed project site is located within the community of Aromas, approximately 600 feet south of the intersection of San Juan Road and Aromas Road (refer to Exhibit 2). No existing stationary sources of noise were identified in the project area that would adversely affect proposed onsite residential land uses. Stationary-source noise associated with the proposed residential development would be primarily associated with the operation of central air conditioning units. To a lesser extent, noise from people talking, amplified music, and use of landscape maintenance equipment may also contribute to intermittent increases in ambient noise levels. However, increases in ambient noise levels from such sources are often sporatic and are typically limited to the less noise-sensitive daytime hours. Noise generated by residential-use central air conditioning units typically averages approximately 60 dba L eq at 3 feet from the source. Given the relatively low density of proposed residential land uses and anticipated distances between residential structures, noise generated by central air conditioning units would not be anticipated to exceed the County s noise standards nor result in a substantial increase in ambient noise levels Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 9 September 7, 2006

at adjacent residential uses. As a result, increased noise levels associated with proposed residential land uses would be considered less than significant. IMPACT 3 Increases in Traffic Noise. Implementation of the proposed project would not contribute to a substantial increase in ambient noise levels. As a result, increases in traffic noise attributable to the proposed project would be considered to have a less-than-significant impact. No mitigation is necessary. The increase in daily traffic volumes resulting from implementation of the proposed project would generate increased noise levels along nearby roadway segments. The FHWA roadway noise prediction model was used to predict traffic noise levels along affected roadway segments. Predicted noise levels were calculated for both background and general plan buildout conditions, with and without implementation of the proposed project, based on traffic volumes obtained from the traffic analysis prepared for this project (Kimley-Horn & Associates, Inc. 2006). Predicted traffic noise levels for near-term conditions, with and without implementation of the proposed project, are summarized in Table 3. Table 3 Predicted Increases in Near-Term Traffic Noise Levels Roadway Segment Near-Term Without Project Predicted Noise Level at 50 ft from Centerline of Near Travel Lane (dba CNEL/Ldn) 1 Near-Term With Project Increase With Project Substantial Increase? 2 San Juan Road, Aromas Road to Carpenteria Road 67.81 67.83 0.02 No San Juan Road, East of Carpenteria Road 67.85 67.91 0.06 No Carpenteria Road, North of Carr Avenue 56.46 56.85 0.39 No Carpenteria Road, Carr Avenue to Rea Road 58.31 58.68 0.37 No Carr Avenue, Rea Road to San Juan Road 63.03 63.27 0.24 No Rea Avenue 46.26 47.48 1.22 No 1. Traffic noise levels were predicted using the FHWA roadway noise prediction model (FHWA-RD-77-108) based on traffic data obtained from the traffic analysis prepared for this project (Kimley-Horn & Associates, Inc. 2006). Predicted noise levels assume no natural or man-made shielding (e.g., vegetation, berms, walls, buildings). 2. Based on increase of 5 dba in areas where ambient noise levels are less than 60 dba CNEL/Ldn; an increase of 3 dba where ambient noise levels range from 60 to 65 dba L dn /CNEL; and an increase of 1.5 dba where ambient noise levels exceed 65 dba L dn /CNEL As noted in Table 3, implementation of the proposed project would result in predicted increases in traffic noise levels ranging from approximately 0.02 dba along San Juan Road to approximately 1.2 dba along Rea Avenue. Implementation of the proposed project would not result in a substantial increase in near-term traffic noise levels in the project area. In future years, with continued development within the area and associated increases in traffic volumes along area roadways, the project s contribution to future cumulative traffic noise levels would decrease. As a result, increases in traffic noise resulting from implementation of the proposed project would be considered less-than-significant. Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 10 September 7, 2006

IMPACT 4 Compatibility of Proposed Land Uses with Projected Ambient Noise Levels. The proposed project could result in the development of residential land uses in areas where predicted noise levels would exceed County noise standards. This impact is considered significant. Mitigation has been incorporated that would reduce traffic noise levels at the proposed residential land use to within acceptable levels. With mitigation, this impact would be considered less than significant. For determination of land use compatibility, predicted traffic noise contours (in dba CNEL/L dn ) for area roadways were modeled for future cumulative-plus-project conditions. Traffic noise contours were modeled using the FHWA roadway noise prediction model, based on data obtained from the traffic analysis prepared for this project. Distances to the 60 and 65 dba CNEL contours for nearby roadways are summarized in Table 4. The predicted noise contour distances do not take into account shielding of noise from existing terrain or existing/future structures. Actual noise levels would vary from day to day, depending on factors such as local traffic volumes, shielding from existing structures, variations in attenuation rates resulting from changes in surface parameters, and meteorological conditions. Table 4 Predicted Traffic Noise Contours Future Cumulative Plus Project Conditions Distance from Roadway Centerline (feet) to Predicted CNEL/Ldn Contour Roadway Segment 60 dba 65 dba San Juan Road, Aromas Road to Carpenteria Road 301 140 Carpenteria Road, Rea Avenue to San Juan Road 227 106 Rea Avenue WR WR Traffic noise levels were calculated using the FHWA roadway noise prediction model (FHWA-RD-77-108) for future cumulative plus project conditions, based on data obtained from the traffic analysis prepared for this project (Kimley-Horn & Associates, Inc. 2006). Assumes no natural or man-made shielding (e.g., vegetation, berms, walls, buildings). WR = Within Roadway Right-of-Way The County s normally acceptable exterior noise standard for residential land uses is 60 dba CNEL. Exterior noise levels of up to 65 dba CNEL may be allowed provided that available noise reduction measures have been implemented to reduce interior noise levels to within acceptable levels. Acceptable noise levels for residential land uses are typically considered to be 45 dba CNEL, or less. Based on the modeling conducted, the 60 dba CNEL contour for nearby Carpenteria Road would extend to approximately 227 feet from the roadway centerline. The projected noise contours for Rea Avenue, located adjacent to the project site s eastern boundary would not extend beyond the roadway right-of-way. Predicted noise levels at the eastern-most project site boundary, which is located in excess of approximately 1,900 feet west of Carpenteria Road, would not be projected to exceed the County s normally acceptable exterior noise standard of 60 dba CNEL. However, both the 60 and 65 dba CNEL contours for nearby San Juan Road, located adjacent to the western boundary of the project site, would be projected to extend onto the project site at distances of approximately 301 and 140 feet from the roadway centerline, respectively. Parcel 31, which is located adjacent to the western boundary of the project site, would be located within the 60 and 65 dba CNEL contours of this roadway (refer to Exhibit 3). Predicted noise levels at Parcel 31would, therefore, exceed the County s normally acceptable exterior noise standard of 60 dba CNEL. As a result, the compatibility of proposed residential land use located on Parcel 31 with predicted onsite noise levels would be considered a potentially significant impact. Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 11 September 7, 2006

Mitigation Measure 4: Compatibility of Proposed Land Uses with Projected Ambient Noise Levels. The residential dwelling proposed for construction on Parcel 31 shall comply with the following provisions: Residential dwelling shall be located no closer than 140 feet from the centerline of San Juan Road; If proposed within 301 feet of the centerline of San Juan Road, the residential dwelling shall be: o oriented to shield outdoor activity areas from direct line-of-sight of San Juan Road; o equipped with central heating and air conditioning; o designed to achieve an interior acoustical requirement of 45 dba CNEL. Within exterior environments of less than approximately 65 dba CNEL, incorporation of central heating and air conditioning, as specified above, and use of exterior windows and doors that have a minimum sound transmission class (STC) rating of 25 is typically sufficient to achieve acceptable interior noise levels. Significance After Mitigation With mitigation, predicted traffic noise levels within the exterior activity areas of the proposed residential dwelling would not exceed the County s conditionally acceptable exterior noise standard of 65 dba CNEL. Incorporation of central heating and air conditioning would allow windows to remain closed during inclement weather conditions to reduce exposure to exterior noise levels. Assuming an average exterior-to-interior noise reduction of 25 dba, with windows closed, predicted interior noise levels would not be anticipated to exceed normally applied interior noise criteria of 45 dba CNEL. For these reasons, this impact is considered less than significant, with mitigation incorporated. Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 12 September 7, 2006

Predicted Noise Contours 60 dba CNEL 65 dba CNEL Note: Predicted noise contours depicted in this exhibit are for land use planning purposes and do not take into account intervening terrain/structures or potential changes in future site conditions. As a result, predicted noise contours should not be interpreted as absolute lines of demarcation. Image Source: GLS 2003 PREDICTED FUTURE CUMULATIVE PLUS PROJECT NOISE CONTOURS EXHIBIT 3 Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 13 September 7, 2006

REFERENCES California, State of. Department of Transportation. January 2002. California Airport Land Use Planning Handbook. California, State of. Governor s Office of Planning and Research. 2003. State of California General Plan Guidelines. County of Monterey. 1988. Monterey County Noise Control Ordinance. County of Monterey. 1993. Monterey County General Plan, Noise Element. Federal Transit Administration (FTA). May 2006. Transit Noise and Vibration Impact Assessment. Goetz Land Surveys (GTS). 2003. Tentative Map of Heritage Oaks. Kimley-Horn and Associates, Inc. (KHA) 2006. Heritage Oaks EIR Traffic Impact Analysis. M. David Egan, McGraw Hill. 1972. Concepts in Architectural Acoustics. U.S. Department of Housing and Urban Development, Office of Community Planning and Development. 1980. The Noise Guidebook. United States Environmental Protection Agency (US EPA). 1971. Noise from Construction Equipment and Operations, Building Equipment, and Home Appliances. United States Environmental Protection Agency (US EPA). March 1974. Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety. Heritage Oaks Subdivision AMBIENT Air Quality & Noise Consulting Noise Impact Analysis 14 September 7, 2006

TRAFFIC NOISE PREDICTION MODELING AVERAGE-DAILY TRAFFIC VOLUMES Near-Term Cumulative No Project (NTNP) With Project (NTWP) No Project (CNP) With Project (CWP) San Juan Road, Aromas to Carpenteria 7,460 7,490 15,500 15,530 San Juan Road, East of Carpenteria 7,520 7,630 16,810 16,920 Carpenteria Road, North of Carr Ave 2,440 2,670 11,460 11,690 Carpenteria Road, Carr Ave to Rea Ave 2,580 2,810 10,520 10,750 Carpenteria Road, Rea to San Juan Rd 2,480 2,620 10,020 10,160 Rea Avenue 1,140 1,510 1,140 1,510 Assumes k-factor of.10 for conversion from peak-hour to ADT. Source: Kimley-Horn and Associates, Inc. 2006 RUN NAME: San Juan Road, Aromas to Carpenteria NTNP RUN DATE: 083006 ADT: 7460 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 67.81 0.0 85.9 184.7 397.8 RUN NAME: San Juan Road, Aromas to Carpenteria NTWP RUN DATE: 083006 ADT: 7490 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 67.83 0.0 86.2 185.2 398.8 RUN NAME: San Juan Road, Aromas to Carpenteria CNP RUN DATE: 083006 ADT: 15500 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 70.99 65.1 139.7 300.6 647.5

RUN NAME: San Juan Road, Aromas to Carpenteria CWP RUN DATE: 083006 ADT: 15530 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 71.00 65.1 139.9 301.0 648.3 RUN NAME: San Juan Road, East of Carpenteria NTNP RUN DATE: 083006 ADT: 7520 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 67.85 0.0 86.4 185.7 399.9 RUN NAME: San Juan Road, East of Carpenteria NTWP RUN DATE: 083006 ADT: 7630 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 67.91 0.0 87.2 187.5 403.8 RUN NAME: San Juan Road, East of Carpenteria CNP RUN DATE: 083006 ADT: 16810 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 71.34 68.6 147.4 317.3 683.5

RUN NAME: San Juan Road, East of Carpenteria CWP RUN DATE: 083006 ADT: 16920 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 71.37 68.9 148.1 318.7 686.4 RUN NAME: Carpenteria Road, North of Carr Ave NTNP RUN DATE: 083006 ADT: 2440 SPEED: 30 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 56.46 0.0 0.0 0.0 69.9 RUN NAME: Carpenteria Road, North of Carr Ave NTWP RUN DATE: 083006 ADT: 2670 SPEED: 30 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 56.85 0.0 0.0 0.0 74.2 RUN NAME: Carpenteria Road, North of Carr Ave CNP RUN DATE: 083006 ADT: 11460 SPEED: 30 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 63.18 0.0 0.0 90.8 195.3

RUN NAME: Carpenteria Road, North of Carr Ave CWP RUN DATE: 083006 ADT: 11690 SPEED: 30 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 63.26 0.0 0.0 92.0 197.9 RUN NAME: Carpenteria Road, Carr to Rea NTNP RUN DATE: 6 ADT: 2580 SPEED: 35 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 58.31 0.0 0.0 0.0 92.7 RUN NAME: Carpenteria Road, Carr to Rea NTWP RUN DATE: 6 ADT: 2810 SPEED: 35 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 58.68 0.0 0.0 0.0 98.1 RUN NAME: Carpenteria Road, Carr to Rea CNP RUN DATE: 6 ADT: 10520 SPEED: 35 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 64.41 0.0 51.2 109.7 236.1

RUN NAME: Carpenteria Road, Carr to Rea CWP RUN DATE: 6 ADT: 10750 SPEED: 35 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 64.51 0.0 52.0 111.3 239.5 RUN NAME: Carpenteria Road, Rea to San Juan NTNP RUN DATE: 6 ADT: 2480 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 63.03 0.0 0.0 88.8 191.0 RUN NAME: Carpenteria Road, Rea to San Juan NTWP RUN DATE: 6 ADT: 2620 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 63.27 0.0 0.0 92.1 198.1 RUN NAME: Carpenteria Road, Rea to San Juan CNP RUN DATE: 6 ADT: 10020 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 69.09 0.0 104.5 224.9 484.2

RUN NAME: Carpenteria Road, Rea to San Juan CWP RUN DATE: 6 ADT: 10160 SPEED: 55 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 69.15 0.0 105.5 226.9 488.7 RUN NAME: Rea Avenue NTNP RUN DATE: 083006 77.69 12.66 9.59 ADT: 1140 SPEED: 20 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 46.26 0.0 0.0 0.0 0.0 RUN NAME: Rea Avenue NTWP RUN DATE: 083006 77.69 12.66 9.59 ADT: 1510 SPEED: 20 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 47.48 0.0 0.0 0.0 0.0 RUN NAME: Rea Avenue CNP RUN DATE: 083006 77.69 12.66 9.59 ADT: 1140 SPEED: 20 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 46.26 0.0 0.0 0.0 0.0

RUN NAME: Rea Avenue CWP RUN DATE: 083006 77.69 12.66 9.59 ADT: 1510 SPEED: 20 ACTIVE HALF WIDTH (FT): 6 CNEL AT 50 FT FROM NEAR TRAVEL LANE CENTERLINE = 47.48 0.0 0.0 0.0 0.0