4.7 NOISE. Introduction. Decibels and Frequency. Perception of the Receiver and A-Weighting

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1 4.7 NOISE Introduction This noise analysis section documents existing noise conditions in the Corridor Plan Area (including the Bay Meadows project site) and vicinity, discusses the noise regulatory context, and estimates future noise impacts to adjacent sensitive receptors due to construction and other ongoing activities (i.e., anticipated vehicular traffic increases along affected local roadways). Throughout this section, references to the Corridor Plan Area include the Bay Meadows project site unless otherwise noted. The setting discussion prepared for the Corridor Plan Area would also be applicable to the regional and local vicinity conditions of the Bay Meadows project site. Discussion of impacts and corresponding mitigation measures are provided separately for each project. Sound and noise are defined as a vibratory disturbance created by a moving or vibrating source that is capable of being detected by the hearing organs. Noise is specifically defined as sound that is loud, unpleasant, unexpected, or undesired and may therefore be classified as a more specific group of sounds. The effects of noise on people can include general annoyance, interference with speech communication, sleep disturbance and, in the extreme, hearing impairment (Caltrans, 1998). Decibels and Frequency In its most basic form, a continuous sound can be described by its frequency or wavelength (pitch) and its amplitude (loudness). Frequency is expressed in cycles per second, or hertz (Hz). Frequencies are heard as the pitch or tone of sound. High-pitched sounds produce high frequencies; low-pitched sounds produce low frequencies. Sound pressure levels (SPL) are described in units called the decibel (db). Decibels are measured on a logarithmic scale that quantifies sound intensity in a manner similar to the Richter scale used for earthquake magnitudes. Thus, a doubling of the energy of a noise source, such as doubling of traffic volume, would increase the noise level by 3 db; a halving of the energy would result in a 3 db decrease. Perception of the Receiver and A-Weighting The human ear is not equally sensitive to all frequencies within the sound spectrum. To accommodate this phenomenon, the A-scale, which approximates the frequency response of the average young ear when listening to most ordinary sounds, was devised. When people make relative judgments of the loudness or annoyance of a sound, their judgments correlate well with the A-scale sound levels of those sounds. Therefore, the A-weighted noise scale is used for measurements and standards involving the human perception of noise. Noise levels using A-weighted measurements are written db(a) or dba. Table shows the relationship of various noise levels to commonly experienced noise events. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

2 Table Typical Noise Levels COMMON OUTDOOR ACTIVITIES NOISE LEVEL (DBA) COMMON INDOOR ACTIVITIES 110 Rock Band Jet Fly-over at 300 meters (1,000 feet) 100 Gas Lawn Mower at 1 meter (3 feet) 90 Diesel Truck at 15 meters (50 feet), at Food Blender at 1 meter (3 feet) km/hr (50 mph) Garbage Disposal at 1 meter (3 feet) Noisy Urban Area, Daytime Gas Lawn Mower at 30 meters (100 feet) 70 Vacuum Cleaner at 3 meters (10 feet) Commercial Area Heavy Traffic at 90 meters (300 feet) 60 Normal Speech at 1 meter (3 feet) Quiet Urban Daytime 50 Large Business Office Dishwasher in Next Room Quiet Urban Nighttime 40 Theater, Large Conference Room (Background) Quiet Suburban Nighttime 30 Library Quiet Rural Nighttime 20 Bedroom at Night, Concert Hall (Background) 10 Broadcast/Recording Studio Lowest Threshold of Human Hearing 0 Lowest Threshold of Human Hearing Source: Caltrans, Technical Noise Supplement, Traffic Noise Analysis Protocol. October Human perception of noise has no simple correlation with acoustical energy. The perception of noise is not linear in terms of dba or in terms of acoustical energy. Two noise sources do not sound twice as loud as one source. It is widely accepted that the average healthy ear can barely perceive changes of 3 dba, increase or decrease; that a change of 5 dba is readily perceptible; and that an increase (decrease) of 10 dba sounds twice (half) as loud (Caltrans 1998). Noise Propagation From the source to the receiver, noise changes both in level and frequency spectrum. The most obvious is the decrease in noise as the distance from the source increases. The manner in which noise reduces with distance depends on the following important factors: Geometric spreading from point and line sources: Sound from a small localized source (approximating a point source) radiates uniformly outward as it travels away from the source in a spherical pattern. The sound level attenuates or drops off at a rate of 6 dba for each doubling of the distance (DD). The movement of vehicles makes the source of the sound appear to emanate from a line (line source) rather than a point when viewed over some time interval. The sound level attenuates or drops off at a rate of 3 dba per doubling of distance. Ground absorption: Hard sites (i.e. sites with a reflective surface between the source and the receiver, such as parking lots or smooth bodies of water) receive no excess ground attenuation, and the changes in noise levels with distance (drop-off rate) is simply the geometric spreading of the source. Soft sites are sites that have an absorptive ground surface such as soft dirt, grass, or scattered bushes and trees and receive an excess ground attenuation value of 1.5 dba/dd. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

3 Atmospheric effects: Wind speed will bend the path of sound to "focus" it on the downwind side and make a "shadow" on the upwind side of the source. At short distances, up to 50 meters, the wind has minor influence on the measured sound level. For longer distances, the wind effect becomes appreciably greater. Temperature gradients create effects similar to those of wind gradients, except that they are uniform in all directions from the source. On a sunny day with no wind, temperature decreases with altitude, giving a "shadow" effect for sound. On a clear night, temperature may increase with altitude, "focusing" sound on the ground surface. Shielding by natural and man-made features, noise barriers, diffraction, and reflection: A large object in the path between a noise source and a receiver can substantially attenuate noise levels at that receiver location. The amount of attenuation provided by this shielding depends on the size of the object and the frequencies of the noise levels. Natural terrain features such as hills and dense woods, as well as man-made features such as buildings and walls, can substantially alter noise levels. Noise Descriptors Several rating scales (or noise metrics ) exist to analyze adverse effects of noise on a community. These scales include the equivalent noise level (L eq ), the community noise equivalent level (CNEL), and the daynight average sound level (L dn ). Average noise levels over a period of minutes or hours are usually expressed as dba L eq, meaning the equivalent noise level for that period of time. The period of time averaging may be specified; L eq (3) would be a three-hour average. When no period is specified, a one-hour average is assumed. It is important to understand that noise of short duration, i.e., times substantially less than the averaging period, are averaged into ambient noise during the period of interest. Thus, a loud noise lasting many seconds or a few minutes may have minimal effect on the measured sound level averaged over a one-hour period. To evaluate community noise impacts, a descriptor was developed that accounts for human sensitivity to nighttime noise. The descriptor is called the DNL or L dn, which represents the 24-hour average sound level with a penalty for nighttime noise. The DNL computation divides the 24-hour day into two periods, daytime (7:00 a.m. to 10:00 p.m.) and nighttime (10:00 p.m. to 7:00 a.m.). Nighttime sound levels are assigned a 10 dba penalty prior to averaging with daytime hourly sound levels. For most highway noise environments, the average noise level during the peak hour traffic volume is approximately equal to the DNL. This DNL description is used to describe noise conditions in the EIR analysis. Noise Sensitive Land Uses A series of land uses have been deemed sensitive by the State of California. Many of these uses depend on low levels of sound to promote the well-being of the occupants or to enjoy the facility. These uses include, but are not necessarily limited to, schools, hospitals, rest homes, long term care facilities, mental care facilities, residential uses, places of worship, libraries, and passive recreation areas. Activities conducted in proximity to these facilities must consider their noise output and ensure that they do not create unacceptable noise levels. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

4 Existing Conditions Existing Noise Environment Major sources of noise affecting the Corridor Plan Area (including the Bay Meadows site) include vehicular traffic on US-101, SR 92, and local roadways. Other noise sources include noise from train passbys on the Caltrain rail line and aircraft flyovers from San Francisco International Airport and San Carlos Airport. To quantify the existing noise environment, nine 10 to 20-minute measurements were made throughout the project area. The measurement locations were selected to represent the location of future noise-sensitive land uses in the project area, existing noise-sensitive receptors and other points of interest in the project area, notably commercial uses along El Camino Real. See Figure for a map of the Corridor Plan Area that indicates the noise measurement locations. Noise Measurements Noise levels were measured at sensitive receptors and other points of interest within the project area during field visits on April 8, 2003 and April 9, Noise measurements were taken between the hours of 1:00 p.m. and 7:00 p.m. on both days. To capture typical noise levels of neighborhoods and traffic on area roadways, and to provide a conservative analysis, noise measurements were taken when no racing occurred at the Bay Meadows racetrack. This is considered conservative (quieter existing conditions) as few cars, if any, were present at the Bay Meadows site and ambient noise levels were not influenced by the Bay Meadows racetrack PA system or patrons of the races. Measured noise levels are shown in Table A discussion of the measured noise levels is provided below. The following discussion provides a description of each noise level measurement and characterization of each measurement location: Measurement 1 was taken within the San Mateo Expo parking area 150 feet south of the intersection of Saratoga Drive and Delaware Street and 50 feet from the east curb line of Delaware Street. This measurement is used to represent existing traffic noise conditions along Delaware Street. Noise levels along Delaware Street are typical for suburban residential neighborhoods. Measurement 2 was located within the Expo parking lot approximately 60 feet southwest of Saratoga Drive across from the Fiesta Gardens neighborhood. Measurement 2 is used to characterize existing traffic noise levels on Saratoga Drive. Measurement 3 was taken 65 feet east of the Caltrain line as it passes through the Bay Meadows site, and represents existing noise levels generated by train passby events and traffic on local roadways influencing the Bay Meadows project site. The Caltrain passby generated maximum levels of 88 dba for less than one second from whistle blasts. Measurement 4 was taken 50 feet north of Hillsdale Boulevard, and represents existing noise levels experienced by residential land uses fronting Hillsdale Boulevard in the Glendale Village neighborhood. Existing noise levels along Hillsdale Boulevard are considered very high and generally unacceptable for residential development. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

5 Table Measured Noise Levels SITE ID* SETUP LOCATION DURATION (MM:SS) L EQ L MIN L MAX 1 A 50 feet east of nearest northbound lane of 10: B Delaware St. 10: A 60 feet southwest of nearest southbound 15: B lane of Saratoga Dr. 15: A 65 feet east of existing train tracks, in Bay Meadows parking lot 4 A 50 feet north of roadway edge of Hillsdale 15: B Ave. 15: A 50 feet south of roadway edge of Concar 15: B Ave. 15: A 50 feet west of the nearest lane of El 10: B Camino Real north of 41 st Ave. 10: A 50 west of nearest lane of El Camino Real 10: B (parking lot of Sears) 10: A 50 feet east of nearest lane of El Camino 10: B Real south of 20 th Ave. 10: A 50 feet west of train tracks centerline at Hayward Park Train Station NORMALIZED MEAN L EQ ** : : * Referenced to Figure ** After normalizing traffic counts to equivalent times and vehicle types, the normalized L eq of setups A and B are averaged to derive a mean. Source: EDAW, Inc. Measurement 5 was taken 50 feet south of Concar Avenue and represents existing traffic generated noise levels along Concar Avenue. Existing noise levels along Concar Avenue are typical for suburban residential neighborhoods. Measurement 6 was taken 50 feet from the easterly edge of El Camino Real and 100 feet north of 41st Avenue and represents traffic-generated noise levels along El Camino Real in the southern portion of the Corridor Plan Area. Measurement 7 was taken in the parking lot of the Hillsdale Shopping Center and represents existing noise levels experienced within the shopping center parking area. Measurement 8 was taken 50 feet from the nearest lane of southbound traffic on a vacant commercial property 150 feet south of 20th Avenue. Measurement 8 represents existing noise levels in the central portion of the Corridor Plan Area. Noise levels measured along El Camino Real range from 65 dba L eq to 70 dba L eq and would typically require noise abatement measures for noise sensitive land uses but are considered acceptable for the existing commercial uses. Measurement 9 was taken 50 feet west of the centerline of the northbound and southbound tracks of the Caltrain tracks in the parking lot of the Haywood Park Train Station. This measurement represents typical noise levels anticipated at 50 feet from a Caltrain station during operation. The Caltrain station stop produced similar maximum noise levels to those experienced during the Caltrain passby. The higher averaged noise levels at this location were likely due to traffic-generated noise from the nearby SR 92. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

6 Source: EDAW, Inc Noise Measurement Locations N feet Corridor Plan Study Area Bay Meadows Project Site FIGURE Noise Measurement Locations San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR February 2004

7 Traffic Counts and Speeds Concurrent with noise level measurements, traffic counts were conducted to determine traffic volumes and the vehicle mix (the percentage of automobiles, medium trucks and heavy trucks to total traffic volume) on roadways adjacent to measurement locations. Traffic counts obtained during the measurement periods were used to field validate noise level measurements and to calibrate the traffic noise prediction model, per Caltrans standards (Caltrans, 1998). Noise Regulations and Guidelines A number of government agencies have established noise standards and guidelines to protect citizens from potential hearing damage and various other adverse physiological and social effects associated with noise. State California Code of Regulations - Title 24 Title 24 of the California Code of Regulations requires that residential structures, other than detached singlefamily dwellings, be designed to prevent the intrusion of exterior noise so that the interior CNEL with windows closed, attributable to exterior sources, shall not exceed 45 dba in any habitable room. See Table for a list of California land use compatibility standards for different land uses. Local City of San Mateo The City of San Mateo has adopted a Noise Element as part of its General Plan (City of San Mateo 1990). Section C of the Noise Element identifies goals and policies for noise in the City. The City of San Mateo General Plan Noise Element contains noise-sensitive land use compatibility guidelines for community noise environments as indicated in Table These guidelines are used to evaluate the suitability of land use changes in terms of noise level exposure. Goals and policies relevant to the proposed Corridor Plan and Bay Meadows project are listed below. GOAL 1: Protect noise sensitive land uses from excessive noise levels. N 1.1: Interior Noise Level Standard: Require submittal of an acoustical analysis and interior noise insulation for all "noise sensitive" land uses listed in Table N-1 (in the San Mateo General Plan) which have an exterior noise level of 60 db (L dn ) or above, as shown on Figure N-1 (in the General Plan). Maximum interior noise level shall not exceed 45 db (L dn ) in all habitable rooms. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

8 Table California Land Use Compatibility for Community Noise Sources LAND USE CATEGORY COMMUNITY NOISE EXPOSURE L DN OR CNEL, DB Residential Low Density Single Family Homes, Duplex, Mobile Homes Residential Multiple Family Transient Lodging Motel, Hotels Schools, Libraries, Churches, Hospitals, Nursing Homes Auditorium, Concert Hall, Amphitheaters Sports Arena, Outdoor Spectator Sports Playgrounds, Neighborhood Parks Golf Courses, Riding Stables, Water Recreation, Cemeteries Office Buildings, Business Commercial and Professional Industrial, Manufacturing, Utilities, Agriculture 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. 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. NORMALLY UNACCEPTABLE New construction or development should be discouraged. If new construction or development does proceed, a detailed analysis of the noise reduction requirement must be made and needed noise insulation features included in the design. CLEARLY UNACCEPTABLE New construction or development clearly should not be undertaken. Source: State of California General Plan Guidelines, Office of Noise Control (June 1990), Illingworth & Rodkin (1990). San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

9 Table City of San Mateo General Plan Noise Sensitive Land Use Compatibility Guidelines for Community Noise Environments (Day/Night Sound Level (DNL), db) LAND USE CATEGORY NORMALLY ACCEPTABLE CONDITIONALLY ACCEPTABLE NORMALLY UNACCEPTABLE Single-family residential Greater than 70 Multi-family residential Greater than 70 Hotels, Motels and Other Lodging Houses Greater than 70 Long-Term Care Facilities Greater than 70 Hospitals Greater than 70 Schools Greater than 70 Multi-Family Common Open Space Intended for the Use and Enjoyment of Residents Greater than 67 1 These guidelines are derived from the California Department of Health Services, Guidelines for the Preparation and Content of the Noise Element of the General Plan, 6/87. The State Guidelines have been modified to reflect San Mateo s preference for distinct noise compatibility categories and to better reflect local land use and noise conditions. It is intended that these guidelines be utilized to evaluate the suitability of land use changes only and not to determine cumulative noise impact. Land uses other than those classified as being noise sensitive are exempt from these compatibility guidelines. 2 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. 3 Conditionally Acceptable -- New construction should be undertaken only after a detailed analysis of the noise reduction requirement is made and needed noise insulation features included in the design. 4 Normally Unacceptable -- New construction should 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. Source: Charles M. Salter Associates, Inc 1996a. N 1.2: Exterior Noise Level Standard: Require an acoustical analysis for new parks, play areas, and multifamily common open space (intended for the use and the enjoyment of residents) which have an exterior noise level of 60 db (L dn ) or above, as shown on Figure N-1 (in the General Plan). Require an acoustical analysis which uses L eq for new parks and play areas. Require feasibility analysis of noise reduction measures for public parks and play areas. Incorporate necessary mitigation measures into residential project design to minimize common open space noise levels. Maximum exterior noise should not exceed 67 db for residential uses and should not exceed 65 db (L eq ) during the noisiest hour for public park uses. GOAL 2: Minimize unnecessary, annoying or unhealthful noise. N 2.1: Noise Ordinance: Continue implementation of the City s existing noise control ordinance: a) which prohibits noise which is annoying or injurious to neighbors of normal sensitivity, making such activity a public nuisance, and b) restricts the hours of construction to minimize noise impact. N 2.2: Minimize Noise Impact: Protect all "noise sensitive" land uses listed in Tables N-1 and N-2 (in General Plan) from adverse impacts caused by the noise generated on-site by new developments. Incorporate necessary mitigation measures into development design to minimize noise impacts. Prohibit long-term exposure increases of 3 db (L dn ) or above at the common property line, or new uses which generate noise levels of 60 db (L dn ) or above at the property line, excluding ambient noise levels. N 2.3: Minimize Commercial Noise: Protect land uses other than those listed as "noise sensitive" in Table N-1 (in General Plan) from adverse impacts caused by the on-site noise generated by new developments. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

10 Incorporate necessary mitigation measures into development design to minimize noise impacts. Prohibit new uses which generate noise levels of 65 db (L dn ) or above at the property line, excluding ambient noise levels. N 2.4: Traffic Noise: Recognize projected increases in ambient noise levels resulting from traffic increases, as shown on Figure N-2 (in General Plan). Promote the installation of noise barriers along highways where "noise sensitive" land uses listed in Table N-1 (in General Plan) are adversely impacted by unacceptable noise levels [60 db (Ldn) or above]. Require adequate noise mitigation to be incorporated into the widening of SR 92 and US 101. Accept noise increases on El Camino Real (SR 82) for existing development, and require new multi-family development to provide common open space having a maximum exterior noise level of 67 db (Ldn). N 2.5: Railroad Noise: Promote the installation of noise barriers along the railroad corridor where noise sensitive land uses are adversely impacted by unacceptable noise levels [60 db (DNL) or above]. Promote adequate noise mitigation to be incorporated into any rail service expansion or track realignment. Study the need for depressing the rail line or other mitigation measures to decrease noise levels prior to substantial expansion of the rail service. Noise guidelines for outdoor activities provided for in the General Plan establish that for parks and playgrounds, 50-65dB (L eq ) is Normally Acceptable and greater than 65dB (L eq ) is Normally Unacceptable. The City of San Mateo Municipal Code does not have specific noise level limits for construction. The City does, however, limit hours of construction. According to Section of the Municipal Code, no work regulated by the code shall be permitted between the hours of 7:00 p.m. and 7:00 a.m., Monday through Friday, nor prior to 10:00 a.m. or after 6:00 p.m. on Saturday, nor prior to noon or after 4:00 p.m. on Sundays. The code does not contain restrictions for holidays. These hours do not apply to construction work that takes place inside a completely enclosed building and does not exceed the exterior ambient noise level as measured ten feet from the exterior property lines. Although the City has no noise level standard for construction noise impacts, a noise level exceeding 80 dba L eq over an 8-hour period at exterior sensitive noise receptors, such as residential yards and patios/balconies, is often considered as the level of significance (FTA, 1995). Sensitive Receptors Corridor Plan Area The Corridor Plan Area is generally bordered on all sides by residential land uses. The majority of the noisesensitive land uses surrounding the project area to the west are not substantially affected by traffic noise within the El Camino Real Corridor as they are generally shielded from major roadways by commercial land uses. Existing noise sensitive land uses located within the proposed Corridor Plan Area include single-family and multiple-family residential land uses located north and south of SR 92 between the Caltrain tracks and El Camino Real in the northwestern portion of the Corridor Plan Area; single family residential land uses located south of 19 th Avenue and west of Delaware Street; and the Fiesta Gardens School located north of Bermuda Drive and south of SR 92. Noise levels at these land uses are predominately influenced by traffic-generated noise on SR 92 and Caltrain operations. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

11 Other potential noise sensitive land uses include the San Mateo Glendale Village Neighborhood (Glendale Village) located to the north and south of Hillsdale Drive between US 101 and El Camino Real; the 19 th Avenue Park Neighborhood (19 th Avenue) located north of Concar Drive between Grant and Delaware Streets; the Fiesta Gardens Neighborhood (Fiesta Gardens) located west of Saratoga Drive, between Delaware Street and the Bay Meadows Phase I project; and the Bay Meadows Phase I neighborhood located south of the Fiesta Gardens neighborhood and north Franklin Drive, east of US-101. The majority of the residences in these neighborhoods consist of single-family dwelling units. A notable exception is the multiplefamily residential properties in the Fiesta Gardens neighborhood that front Delaware Street. Some of the residential neighborhoods have noise abatement barriers constructed due to previous projects in the area, such as the Bay Meadows Phase I development. The residential properties within the Fiesta Gardens neighborhood have noise abatement barriers that are common to all receptors along Saratoga Avenue. The Bay Meadows Phase I neighborhood has noise abatement barriers for properties along US-101. The residential properties within the Glendale Village neighborhood that front McLellan Avenue, and back the proposed Franklin Parkway extension, have an eight-foot masonry wall to the north. There are no existing noise abatement barriers common to all residences within the 19 th Avenue Park neighborhood. Bay Meadows Specific Plan At the western end of the Bay Meadows project site along Saratoga Drive, the main noise source is traffic on US-101. The major noise source at the northern end of the site is traffic on SR 92. At the eastern end of the site, the main noise is from distant traffic on El Camino Real and Caltrain operations, which consist of a train passing in approximately 15-minute intervals. The only major noise source in the southern end of the site is Hillsdale Boulevard. However, due to intervening residential land uses located north of Hillsdale Drive, noise in this area is predominately generated by traffic on US-101. There are no sensitive receptors on the Bay Meadows site; however, residences are located immediately to the south of the site that front McLellan Avenue as well as to the northeast in the Fiesta Gardens neighborhood. Impacts and Mitigation Measures Introduction The impact analysis investigates whether the proposed Corridor Plan and the Bay Meadows project could result in temporary (or intermittent) noise impacts associated with demolition/construction activities or longterm impacts that are anticipated to be primarily due to on-site noise sources or an increase in the number of vehicle trips traveling on local and regional roadways. Significance Criteria Based on the California Environmental Quality Act (CEQA), the proposed project would result in a significant noise impact if it would result in: San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

12 Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies. Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels. A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project. A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project. For the purposes of this EIR, significant noise impacts are determined as follows: Construction Noise Impacts Project impacts would be considered significant if construction activities occur outside the hours of 7:00 a.m. to 7:00 p.m., Monday through Friday, 10:00 a.m. to 6:00 p.m. on Saturday, and noon to 4:00 p.m. on Sundays, as provided by Section of the City s Municipal Code. Stationary Noise Impacts According to Policy N 2.2 of the San Mateo General Plan Noise Element, project stationary impacts would be considered significant if noise generated on-site by new developments would generate noise levels of 60 db (DNL) or above, and increase background noise levels by 3 db (DNL) or more at property lines of existing noise sensitive development. For other than noise sensitive land uses, the noise level at common property lines should not exceed 65 db (DNL) or result in an increase in background noise levels of 3 db (DNL). Roadway Traffic Noise Impacts According to Policy N 2.4 of the San Mateo General Plan Noise Element, project impacts may be considered significant if project-related increases in roadway traffic would result in noise levels that exceed those considered Normally Acceptable (as indicated in Table 4.7-4). In areas where the Normally Acceptable standard is currently exceeded under Baseline or General Plan 2020 conditions, impacts are evaluated based on the project-related increase in traffic noise levels, with a significant impact occurring where an increase of 3 dba or more would result. Railway Noise Impacts A significant impact would be considered to occur if existing railway (i.e. Caltrain) noise levels would exceed 60 db (DNL) for incompatible land uses such as single and multiple family dwellings, trailer parks, schools of standard construction, hospitals, and childcare facilities built as a result of the project. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

13 Aircraft Impacts A significant impact would be considered to occur if existing aircraft noise levels would exceed 65 CNEL for incompatible land uses such as single and multiple family dwellings, trailer parks, schools of standard construction, hospitals, and childcare facilities built as a result of the project. Methodology Because the proposed Corridor Plan does not define specific future development activities within the plan area, but rather allows for and encourages specific types of development, impacts were determined based on the minimum and maximum potential development allowed under the proposed plan, known as Scenarios A and Z, respectively. Additionally, as development would occur over the entire planning period (i.e., no opening year), assessments are made based on future conditions, which for the Corridor Plan is defined as To assess impacts, the Corridor Plan is evaluated against General Plan 2020 conditions. The Bay Meadows project is evaluated against Baseline conditions (existing conditions plus approved projects) for existing plus project impacts. To determine cumulative impacts associated with the Bay Meadows project, Corridor Plan Z conditions were compared to General Plan 2020 conditions because this scenario would result in more intensive development and related impacts than would the Bay Meadows plus Corridor Plan Z scenario, which replaces Corridor Plan Z s assumptions for the Bay Meadows site with the less intensive Bay Meadows project. Because Corridor Plan Z would represent a worst-case scenario for cumulative impacts of the Bay Meadows project, Corridor Plan A and Bay Meadows Project plus Corridor Plan A are not assessed here. For locations where noise levels under Existing, Baseline or General Plan 2020 conditions exceed City noise level standards, impacts are evaluated against a 3 dba noise level increase criterion. For the Corridor Plan, impacts were modeled at 50 feet from the nearest lane of traffic flow and assessed for El Camino Real, Hillsdale Boulevard, Delaware Street, Concar Avenue, Grant Avenue, Saratoga Drive, and Franklin Parkway. Based on a review of the Bay Meadows Phase II and Transportation Corridor Plan Transportation Impact Analysis prepared in August 2003, no significant increases in traffic volumes are anticipated on local streets as a result of the proposed Corridor Plan, and as a result, local streets were not analyzed for noise level increases. The proposed Bay Meadows project would eliminate existing Bay Meadows racetrack operations and could result in the complete redevelopment of the site with a maximum of 2.1 million gross square feet (gsf) of office space, 1,500 residential units, 100,000 gsf of retail space, and 29.5 acres of open space (of which 15.6 acres would be devoted to parks and public plazas). Similar to the Corridor Plan, the residential units, office space, and retail space represent the maximum that could be built; depending on market conditions, fewer, if any, of these uses could be built. For the purposes of analysis in this EIR, the maximum figures are assumed to be the proposed project. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

14 For the Bay Meadows project, impacts were modeled at known receivers, based on aerial photographs and information obtained from the site survey. For planned roadways, noise levels were modeled at 50 feet from the nearest lane of traffic flow. Noise impacts were assessed for Hillsdale Boulevard, Delaware Street, Saratoga Drive, and Franklin Parkway. Additionally, freeway traffic noise has been estimated for future conditions to assess potential impacts to the project from traffic on US-101. Impacts for the Corridor Plan and the Bay Meadows project are provided below separately. Corridor Plan Impacts and Mitigation Measures Construction Noise Impact Noise-CP1: Construction activities related to development associated with the Corridor Plan (Scenarios A and Z) would potentially result in temporary increases in noise levels at nearby sensitive land uses. This would be a significant impact. Noise impacts from construction are a function of the noise generated by the construction equipment, the location and sensitivity of nearby land uses, and the timing and duration of the noise-generating activities. Noise levels within and adjacent to the specific construction sites would increase during the construction period. Construction would not cause long-term impacts since it would be temporary and the hour of daily construction would be limited by the City s construction noise Municipal Code (Section ). In general, construction activities are carried out in phases and each phase has its own noise characteristics based on the mix of construction equipment in use. Typical noise levels at a distance of 50 feet from the noise source for each of the major phases of construction are shown in Table Even though the noise levels in the table represent typical values, there can be wide fluctuations in the noise emissions of similar equipment. Table Typical Noise Level Ranges at Construction Sites CONSTRUCTION PHASE AVERAGE NOISE LEVEL AT 50 FEET MINIMUM REQUIRED EQUIPMENT ON-SITE ALL PERTINENT EQUIPMENT ON-SITE Clearing 84 dba 84 dba Excavation 78 dba 89 dba Foundation/Conditioning 88 dba 88 dba Pile Driving 93 dba 93 dba Paving 78 dba 79 dba Finishing and Cleanup 84 dba 84 dba Source: Bolt, Beranek and Newman, Noise from Construction Equipment and Operations, Building Equipment, and Home Appliances, prepared for the U.S. Environmental Protection Agency, San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

15 Construction noise levels at and near locations on a project site would fluctuate depending on the particular type, number, and duration of use of various pieces and types of construction equipment. Redevelopment envisioned throughout the Corridor Plan Area would not occur entirely simultaneously. Improvements, renovations, and new construction would occur in response to market forces. The effect of construction noise would depend upon the amount and type of construction planned under each phase, the distance between construction activities and the nearest noise-sensitive receptor, and the existing noise levels at those uses. The assessment of construction noise is based upon maximum noise levels due to construction equipment at a reference distance of 50 feet (Table 4.7-5). With the exception of pile drivers, construction equipment would generate maximum noise levels of approximately 89 db at 50 feet. Pile drivers would produce noise levels of approximately 93 db at a distance of 50 feet. Using a typical noise attenuation rate of 6 db per doubling of distance, the predicted maximum noise level at residences within 1,250 feet of construction sites are expected to be between 89 dba (50 feet) and 61 dba (1,250 feet), due to equipment other than pile drivers. If pile drivers are used for construction, the predicted maximum noise level at residences is expected to be between 93 dba (50 feet) and 61 dba (2,000 feet). While construction noise levels would be temporary in nature at any individual construction site, due to a lack of a defined construction schedule or phasing plan identifying proposed construction hours and the potential for noise levels in excess of 80 dba Leq at nearby residences, construction impacts are considered significant. Similar impacts, although with potentially fewer occurrences, would occur under Corridor Plan A, and similar mitigation would be required for Corridor Plan A. Mitigation Measure Noise-CP1: The following measures would be required to reduce potential noise impacts to a less than significant level: All diesel equipment shall be operated with closed engine doors and should be equipped with factory-recommended mufflers. Pile-driving activities shall be restricted to between 8:00 a.m. to 5:00 p.m., Monday through Friday, to limit the intrusiveness of pile driving during the morning and evening hours. This measure is suggested only for construction sites that would use pile drivers within 2,000 feet of residential or sensitive land uses. Proposed walls or barriers shall be installed as early as possible to help reduce noise from construction activities. Stationary construction equipment shall be kept beyond 100 feet of existing residences. Noise attenuation techniques will be employed as needed and feasible to reduce noise levels below 100 dba L eq in commercial/industrial areas and below 80 dba L eq at exterior locations in residential areas. Such techniques may include the use of sound blankets on noise generating equipment and the construction of temporary sound barriers between construction sites and affected uses. Noise attenuation techniques will be verified through measurement of noise levels. Whenever feasible, electrical power should be used to run air compressors and similar power tools. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

16 Contractors shall use "quiet" models of any conventionally noisy construction equipment such as air compressors, jackhammers and other impact tools, as feasible. Contractors shall designate an employee as the construction noise coordinator and provide an on-site sign that will identify the person and provide a contact number. The coordinator would be responsible for receiving calls from residents or businesses regarding specific construction noise-related complaints. The coordinator would then be responsible for taking appropriate measures to reduce or eliminate noise levels as appropriate. Complaints and the response should be logged and kept on file for review by the City. The construction noise coordinator would act as a liaison between the residents in the vicinity of the construction and the contractor, so perceived noisy activities are addressed as soon as possible. Significance After Mitigation: Less than significant. Stationary Source Impacts Impact Noise-CP2: Stationary noise related to development associated with the Corridor Plan (Scenarios A and Z) could impact new and existing sensitive land uses. This would be a significant impact. Truck deliveries and mechanical equipment related to development associated with the Corridor Plan (Scenarios A and Z) may be a source of elevated noise levels at local residences. 1 Noise generated by early morning truck deliveries is generally related to back-up alarms and loading and unloading activities. Mechanical equipment noise is typically associated with compressors, vent-fans and pumps. Since truck deliveries and mechanical equipment may be audible and could exceed the City's threshold of 60 db DNL at nearby noise receptors, this impact may be considered potentially significant. Mitigation Measure Noise-CP2: The City shall require noise control measures for any mechanical equipment within the Corridor Plan Area as needed to reduce mechanical equipment noise to DNL of 60 db at the property line of adjacent or nearby residences, per the City s Noise Element. At a minimum, the following measures shall be implemented: All proposed projects shall be designed so that loading areas face away from the residences to minimize potential noise levels at the nearby residences. All proposed developments, as feasible, shall specify equipment that meets the City s noise standard of 60 db at the nearest receptor without special enclosures or mufflers. Mechanical equipment shall be located as far away from nearby residential land uses as feasible. As necessary, a separate noise barrier or enclosure shall be constructed around mechanical equipment to block line-of-sight between the equipment and nearby residences. 1 During delivery activities trucks are considered stationary noise sources due to the limited movement for backing up and maneuvering within parking areas, similar to construction activities. San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

17 Significance After Mitigation: Less than significant. Compatibility of Proposed Land Uses with the Noise Environment Impact Noise-CP3: The Corridor Plan (Scenarios A and Z) would result in the development of sensitive new land uses that could potentially be impacted by existing noise levels. This would be a significant impact. While future development would be required to conform to the City s General Plan regarding the location of proposed land uses and noise evaluation requirements, including detailed acoustical studies for noise sensitive developments to be located in areas with exterior noise levels in excess of 60 dba DNL, the proposed Corridor Plan does not propose specific land uses at any particular location and does not specify noise attenuation features. Due to the uncertainty of future land use location, it is not possible to determine if future land uses would be compatible with the future noise environment at this time. Therefore, it is concluded that the proposed project could potentially result in a significant impact related to noise compatibility. Estimated distances from the centerline of studied roadways to the 60 dba DNL contour are presented in Table to assist in determining which developments are likely to be exposed to excessive noise levels. Mitigation Measure Noise-CP3: All proposed noise sensitive developments, as defined by the City s General Plan (residential, schools, and medical care facilities, etc.) proposed to be located in areas where exterior noise levels exceed 60 dba DNL shall have a detailed acoustical report prepared that shows interior noise levels would not exceed 45 dba DNL in all habitable rooms and that exterior noise levels in habitable areas would not exceed 67 dba as per the City s Noise Element Policies N 1.1 and N 1.2, respectively. The acoustical analysis shall be prepared as part of the final design. Noise control measures shall be designed according to the type of building construction and specified sound rating for each building element. Significance After Mitigation: Less than significant. Traffic Noise Impact Noise-CP4: Additional vehicular traffic resulting from development associated with the Corridor Plan (Scenarios A and Z) would result in increases in project area noise levels. This would be a less than significant impact. In order to determine the future noise levels on local roads, a combination of noise measurements and noise models were used. For existing noise levels, the measured data were used. For future noise levels, the noise impacts were evaluated with the Federal Highway Administration s traffic noise prediction model (FHWA- RD ). The FHWA model uses hourly traffic volumes, travel speeds, and the vehicle mix to predict the peak hour noise level (L eq ) along a roadway. Assuming 85% of the daily traffic in the project area would San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

18 occur between the hours of 7:00 a.m. and 10:00 p.m. and 15% would occur between the hours of 10:00 p.m. and 7:00 a.m. the following day, the Peak Hour L eq is approximately 0.1 dba lower than the equivalent DNL. As a result, the L eq has been used to conservatively evaluate traffic noise impacts. The Corridor Plan s contribution to future traffic conditions was determined by comparing Corridor Plan Z conditions to General Plan 2020 conditions. Table summarizes future noise levels due to the General Plan and Corridor Plan. Table Future Traffic Noise Levels (in dba) (50 feet from the Roadway Centerline) ROADWAY AND SEGMENT GENERAL PLAN 2020 CORRIDOR PLAN Z (2020) DIFFERENCE DISTANCE TO 60 DB DNL (IN FEET) El Camino Real North of Crystal Springs Crystal Springs to 3rd Ave rd Ave to Barneson Ave Barneson Ave to 17th Ave ,094 17th Ave to 20th Ave ,618 20th Ave to 25th Ave ,227 25th Ave to 28th Ave ,199 28th Ave to 41st Ave ,545 South of 41st Ave ,409 Delaware Street 9th Ave to Concar Ave Concar Ave to Saratoga Saratoga to 25th Ave th Ave to 28th Ave th Ave to Pacific Ave Saratoga Drive Delaware to Franklin Ave Franklin to Hillsdale South of Hillsdale Concar Avenue West of Delaware Delaware to Grant West of Grant Hillsdale Avenue Norfolk to 110 NB Ramp NB Ramp to SB Ramp SB Ramps to Saratoga Saratoga to Curtis ,094 Saratoga to El Camino Real Franklin Parkway US-101 to Saratoga Saratoga to Curtis Curtis to Delaware/Pacific N/A 46 Tenths are only for the purpose of showing the calculated magnitude of the change, rounding should otherwise be applied. N/A = No roadway exists with which to compare future noise levels. Source: EDAW, Inc., 2003 San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.

19 As shown in Table 4.7-6, noise levels within 50 feet of the centerline of all of the studied roadways, except for Franklin Parkway, where it borders the Glendale Village Neighborhood, would exceed Normally Acceptable city standards (60 dba) for noise sensitive land uses with or without the implementation of Corridor Plan Z. Noise levels along Franklin Parkway, where it borders the Glendale Village Neighborhood, would be consistent with the City standards. The Corridor Plan would not cause noise levels along local roadways to exceed City standards or contribute to increases of 3.0 dba or more in areas already exceeding City s standards. Therefore, project-generated noise impacts would be considered less than significant. Mitigation Measure Noise-CP4: None required. Other Noise Impacts Impact Noise-CP5: The Corridor Plan (Scenarios A and Z) would result in the introduction of additional development within the Corridor Plan Area that would be exposed to aircraft noise levels projected to be less than the State standard of 65 CNEL. This would be a less than significant impact. Land uses within the Corridor Plan Area would be exposed to minor aircraft noise. According to the San Mateo General Plan, aircraft operation and approach at the San Francisco International Airport does not impact the project area. Small general aviation aircraft from the San Carlos Airport are audible in the project area, however. According to the County s Airport Planning Department, a departure path from San Carlos Airport called the Bay Meadows departure takes general aviation aircraft over the City under certain unusual weather conditions. The approach path is used infrequently. Noise contours for the San Carlos Airport are shown in the San Mateo County Airport Land Use Plan. According to the Plan, the project area is outside the CNEL 65 contour. Since on-site aircraft noise levels are projected to be less than the State standard of 65 CNEL, aircraft noise is considered to be a less than significant impact. Mitigation Measure Noise-CP5: None required. Impact Noise-CP6: The Corridor Plan (Scenarios A and Z) would result in the introduction of additional development within the Corridor Plan Area that would be exposed to train-related noise levels. This would be a significant impact. Land uses within the Corridor Plan Area would be exposed to train noise. According to the City of San Mateo's noise contours and the Caltrain Short-Range Transit Plan, future train usage would produce noise levels in excess of the City's threshold of 60 db (DNL) for properties located within 530 feet of the centerline of the Caltrain Tracks. Currently, 60 Caltrain passages occur each day. Existing train activity is audible throughout the Plan area. According to the City s existing noise contours, the DNL from existing train activities is 65 dba at 210 feet San Mateo Corridor Plan and Bay Meadows Specific Plan Amendment EIR EDAW, Inc.