Dormitory Authority of the State of New York Page 14-1 Section 14. Noise Introduction This section analyzes the potential noise impacts of the Proposed Project. Projectgenerated noise sources include mobile sources from increased vehicles accessing the site, and stationary sources such as ventilation equipment and operating equipment. Environmental noise is defined as the sound in a community emanating from man-made sources such as automobiles, trucks, buses, aircraft, trains, and fixed industrial sources, or from natural sources such as animals and wind. Sound levels are measured in logarithmic units called decibels ( db ). An overall measurement of sound results in a single decibel value that describes the sound environment, taking all frequencies (pitches) into account. The human ear, however, does not sense all frequencies in the same manner. The A -weighted scale (expressed in dba units) was developed to closely approximate the human sensory response from highway-related noise. The ability of an average individual to perceive changes in noise levels is well documented. Generally, an increase of less than 3.0 dba is barely perceptible to most listeners, a 5.0 dba increase is readily noticeable, and a 10.0 dba increase normally is perceived as a doubling of noise. A list of typical community sound levels is shown in Table 14-1. Table 14-1. Noise Levels of Common Sources Sound Source Sound Pressure Level (dba) Air Raid Siren at 50 feet 120 Maximum Levels at Rock Concerts (Rear Seats) 110 On Platform by Passing Subway Train 100 On Sidewalk by Passing Heavy Truck or Bus 90 On Sidewalk by Typical Highway 80 On Sidewalk by Passing Automobiles with Mufflers 70 Typical Urban Area 60-70 Typical Suburban Area 50-60 Quiet Suburban Area at Night 40-50 Typical Rural Area at Night 30-40 Isolated Broadcast Studio 20 Audiometric (Hearing Testing) Booth 10 Threshold of Hearing 0 Source: CEQR Technical Manual, 2001 Cowan, James P., Handbook of Environmental Acoustics, 1994 and Egan, M. David, Architectural Acoustics, 1988. Since an instantaneous noise measurement (measured in dba) describes noise levels at just one moment of time, and since very few noises in a community area are constant, other descriptors are used to represent varying sound levels over extended periods of time. The equivalent noise level (L eq ) represents the time-varying noise level produced over a period of time, as a single number over a specified period of time. This represents the equivalent steady noise level, which, over a given period, contains the same energy as the time-varying noise during the same period. The most common time period is the noise over one hour, represented as L eq (h). This descriptor is commonly used to express results from noise measurements, predictions and
Dormitory Authority of the State of New York Page 14-2 impact assessments. Other descriptors often used in noise analyses are L 10 and L dn. L 10 is defined as the sound pressure level exceeded 10 percent of the time and is often used to describe noise generated from traffic sources. It is also used as a noise descriptor for the CEQR Noise Exposure Guidelines described below. L dn is the day-night equivalent sound level, defined as a 24-hour continuous L eq with a 10.0 db adjustment added to all hourly noise levels recorded between the hours of 10:00 p.m. and 7:00 a.m. L dn is often used in the analysis of both aircraft and train noise. CEQR Technical Manual guidance suggests that the duration of noise measurements should be sufficient to ensure that noise measurements are reflective of ambient conditions and to determine that the duration of the measurement period is sufficiently long to encompass typical events and conditions. According to Section 331.2 of the CEQR Technical Manual, noise measurements should be made in accordance with the expected times that the proposed activity at the Project Site would be greatest, typically during the peak weekday traffic hours. 179 The Proposed Project, as a courthouse facility, would function similar to an office use with the majority of activity on the Project Site occurring during business hours. Since the Proposed Project would be expected to generate the most noise during the peak hours, and minimal projectrelated noise would occur during the nighttime, measurements were taken during the peak a.m., midday, and p.m. hours, and the analysis was performed for these hours. For the purposes of this analysis, the 1-hour L eq will be used to describe traffic and stationary source noise impacts, and the L 10 descriptor will be used to compare the project to the CEQR Noise Exposure Guidelines as described in Sections 123.1 and 420 of the CEQR Technical Manual. 180 Noise Standards and Criteria CEQR Noise Impact Thresholds The New York City Department of Environmental Protection ( NYCDEP ) has established standards for noise exposure at sensitive receptors resulting from the implementation of a project. 181 The impact thresholds are described below: An increase of 5.0 dba or greater over the No-Build noise level would be an impact if the No-Build noise level is 60.0 dba or less. If the No-Build noise level is 61.0 dba, a 4.0 dba increase or greater would be considered significant. If the No-Build noise level is 62.0 dba or more, a 3.0 dba increase or greater would be considered significant. A significant impact would occur during the nighttime period (defined by CEQR standards as being between 10:00 p.m. and 7:00 a.m.) if there is a change in noise levels of 3.0 dba or more. CEQR Noise Exposure Standards The NYCDEP has also promulgated standards that apply to a Proposed Project if it is also a sensitive receptor such as a residence, hospital, or school, or office. 182 The NYCDEP has established four categories of acceptability based on receptor type and land use for vehicular 179 CEQR Technical Manual, p. 3R-12. 180 CEQR Technical Manual, pp. 3R-3-3R-18. 181 CEQR Technical Manual, p. 3R-18. 182 CEQR Technical Manual, Table 3R-3, p. 3R-19.
Dormitory Authority of the State of New York Page 14-3 traffic, rail, and aircraft related noise sources. The categories include generally acceptable, marginally acceptable, marginally unacceptable, and clearly unacceptable. These guidelines are shown in Table 14-2. Table 14-2. Noise Exposure Guidelines for use in City Environmental Impact Review 1 Receptor type 1. Outdoor area requiring serenity and quiet 2 2. Hospital, Nursing Home 3. Residence, residential hotel or motel 4. School, museum, library, court, house of worship, transient hotel or motel, public meeting room, auditorium, out-patient health facility 5. Commercial or office Time period Acceptable General External Exposure L 10 55.0 dba Airport Exposure 3 Marginally Acceptable General External Exposure Airport Exposure 3 Marginally Unacceptable General External Exposure Airport Exposure 3 Clearly Unacceptable General External Exposure L 10 55.0 dba 55.0 < L 10 65.0 dba 65.0 < L 10 80.0 dba L 10 > 80.0 dba 7a.m. L 10 p.m. 10 65.0 dba 65.0 < L 10 70.0 dba 70.0 < L 10 80.0 dba L 10 > 80.0 dba 10 p.m. L 7 a.m. 10 55.0 dba 55.0 < L 10 70.0 dba 70.0 < L 10 80.0 dba L 10 > 80.0 dba ---------------------------- L dn 60.0 dba ------------ ------------------ ---------------- 60.0< L dn 65.0 dba -------- ------------------ Day (7:00 a.m. -- (I) 65.0 < L dn 70.0 dba, (II) 70.0 dba L dn ----------- 6. Industrial, public areas only 4 Note 4 Note 4 Note 4 Note 4 Note 4 Notes: (I) In addition, any new activity shall not increase the ambient noise level by 3.0 dba or more: 1. Measurements and projections of noise exposures are to be made at appropriate heights above site boundaries as given by ANSI Standards; all values are for the worst hour in the time period. 2. Tracts of land where serenity and quiet are extraordinarily important and serve an important public need and where the preservation of these qualities is essential of the area to serve its intended purpose. Such areas could include amphitheaters, particular parks or portions of parks or open spaces dedicated or recognized by appropriate local officials for activities requiring special qualities of serenity and quiet. Examples are grounds for ambulatory hospital patients and patients and residents of sanitariums and old-age homes. 3. One may use FAA-approved Land contours supplied by the Port Authority, or the noise contours may be computed from the federally approved INM Computer Model using flight data supplied by the Port Authority of New York and New Jersey. 4. External Noise Exposure standards for industrial areas of sounds produced by industrial operations other than operating motor vehicles or other transportation facilities are spelled out in the New York City Zoning Resolution, Sections 42-20 and 42-21. The referenced standards apply to M1, M2, and M3 manufacturing districts and to adjoining residence districts (performance standards are octave band standards). Source: New York City Department of Environmental Protection (adopted by NYCDEP for use in CEQR-1983) Since this project is a courthouse, the new facility would be classified as a sensitive receptor, and requires analysis of the Noise Exposure. New York City Noise Code The New York City Noise Code establishes ambient noise quality zone ( ANQZ ) criteria and standards based on existing zoning designations (Refer to Table 14-3). 183 The Airport Exposure 3 ------------------- L dn 75.0 dba ----------- ----------------
Dormitory Authority of the State of New York Page 14-4 Proposed Project is located in an area zoned as a C4-2 General Commercial District. Commercial zones are designated as noise quality zone N-3 in the New York City Noise Ordinance. These standards apply to noise emitted directly from stationary activities due to regular use within the boundaries of a project. The standards do not apply to noise occurring off the site, such as traffic noise and aircraft noise, and also do not apply to construction noise. Refer to Section 19, Construction Impacts for applicable standards related to construction noise. Table 14-3. New York City Noise Code Standards for Use and Noise Daytime standards (7:00 a.m. - Ambient Noise Quality Zone Noise quality zone N-1 (Low density residential RL; landuse zones R-1 to R-3) Noise quality zone N-2 (High density residential RH; land-use zones R-4 to R-10) Noise quality zone N-3 (All Commercial and manufacturing land-use zones) L eq =60.0 db(a) measured for any one hour L eq =65.0 db(a) measured for any one hour L eq =70.0 db(a) measured for any one hour Source: New York City Department of Environmental Protection Noise Code, revised July1, 2007. Existing Conditions Nighttime standards (10:00 p.m. - 7:00 a.m.) L eq =50.0 db(a) measured for any one hour L eq =55.0 db(a) measured for any one hour L eq =70.0 db(a) measured for any one hour The area surrounding the Project Site is predominantly characterized by mixed commercial and residential land uses with public facilities near the north end of the site. Land uses adjacent to the roadways anticipated to be used to access the new garage include multifamily residential, mixed residential/commercial, commercial, parking, and public facilities and institutions. Noise sensitive resources in the vicinity of the Project Site include residences on St. Marks Place, Central Avenue, Slosson Terrace, Bay Street, and Victory Boulevard, and the St. George Library on Central Avenue. These resources are represented by the four noise analysis locations shown on Figure 14-1. The locations include: Site 1, St. Marks Place Residences; Site 2, St. George Library Center and North of Garage Entrance; Site 3, South of Garage Entrance; Site 4, Slosson Terrace Residences. These noise analysis locations were chosen to represent the areas containing sensitive resources anticipated to have the greatest percentage increase in traffic volumes, and thus the greatest increase in sound levels. 2007. 183 New York City Department of Environmental Protection, New York City Noise Code. Revised July 1,
Fort Hill Circle Hudson County Richmond County New York City Boundary 1. St. Marks Place Residences 2. St. George Library Center / 3. 4. Slosson Terrace Residences Richmond St. Marks Place Terrace Westervelt Avenue Webster Avenue Jersey Street York Avenue Ely Street Jersey Street Stanley Avenue Castleton Avenue Victory Boulevard Cleveland Street Beechwood Avenue Cebra Avenue Egmont Place Layton Avenue Taft Avenue Hendricks Avenue Bismark Avenue Curtis Place Crescent Avenue Benzinger Avenue Winter Avenue Scribner Avenue Corson Avenue Brook Street Hamilton Avenue Westervelt Avenue Sherman Avenue Ward Avenue Vine Street Fort Place Low Terrace Nixon Avenue Belmont Place Academy Pl. Monroe Avenue Victory Boulevard Tompkins Circle Wall Street Montgomery Avenue St. Pauls Street 1 Hyatt Street St. Marks Place Stuyvesant Place Richmond Terrace Central Avenue Van Duzer Street Hannah Street Swan Street Grant Street Clinton Street Brewster Street 2 3 Bay Street 4 Borough Place Slosson Terr. Van Duzer Street Bay Street Project Site Interim Construction-Period Parking Borough Boundary Area Lots 0 0.25 0.5 Miles Source: NYC Department of City Planning; Field Inspection Primary Study Area Secondary Study Area Noise Analysis Locations Figure 14-1: Noise Analysis Locations Staten Island Supreme Courthouse Project
Dormitory Authority of the State of New York Page 14-6 Data Collection To assess existing sound levels, noise monitoring was performed during the traffic peak periods in the a.m., midday, and p.m. Following procedures outlined in the CEQR Technical Manual, a 20-minute measurement, representative of a 1-hour L eq, was taken at street level. 184 A Bruel & Kjaer Type 2236 Precision Integration Sound Level meter was used to measure existing sound levels. This meter is microprocessor-based and measures noise levels in accordance with all current noise exposure criteria. During the noise-monitoring period the meter was tripod-mounted and equipped with a windscreen to eliminate noise associated with wind blowing across the microphone. The sound meter was calibrated with an acoustical calibrator before and after each measurement. Weather conditions on the days of monitoring were noted. The recommended meteorological conditions for noise monitoring are: Wind speed under 12.0 miles per hour ( mph ); Relative humidity under 90 percent; Temperature above 14 o Fahrenheit ( F ) and below 122 o F. The weather conditions during noise monitoring fell within these parameters. Traffic and classification counts were conducted concurrently with the noise monitoring. Traffic and classification counts are used to calculate the maximum hourly Passenger Car Equivalents ( PCEs ). Passenger Car Equivalents are used to account for the different types of motor vehicles (i.e., cars, trucks etc.) and their varying levels of sound. According to the CEQR Technical Manual, the relationships used for calculating PCEs are as follows: 1 automobile is equivalent to 1 PCE; 1 medium truck is equivalent to 13 PCEs; 1 bus is equivalent to 18 PCEs; and 1 heavy truck is equivalent to 47 PCEs. In other words, the noise level produced by a medium truck would be the same as that from 13 cars and, the noise level from a heavy truck would be equivalent to that of 47 cars. The results of the noise monitoring program are shown in Table 14-4. Table 14-4. Noise Monitoring Data Site Location Time PCEs L eq (dba) L 10 (dba) A.M. 237 63.3 66.8 1 St. Marks Place Residences 2 3 Midday 261 63.6 66.5 P.M. 414 62.9 66.5 A.M. 231 59.9 62.5 Midday 270 63.7 66.5 St. George Library Center and North of Garage Entrance P.M. 315 60.7 63.6 South of Garage Entrance 4 Slosson Terrace Residences Source: Jacobs Edwards and Kelcey, 2007 A.M. 520 64.5 67.7 Midday 273 63.5 66.0 P.M. 244 61.3 65.1 A.M. 411 63.7 65.8 Midday 153 61.9 64.5 P.M. 329 62.3 64.9 184 CEQR Technical Manual, p. 3R-12-3R-13.
Dormitory Authority of the State of New York Page 14-7 The Noise Exposure Guidelines recommended by the New York City Department of Environmental Protection ( NYCDEP ) and identified in Table 12-2, are expressed in terms of L 10 for vehicular noise. 185 In order to apply these guidelines, identified in Table 12-2, L eq noise levels were converted to L 10 by adding an adjustment factor of 3.0 dba to L eq per FHWA suggested guidance. 186 Noise exposure levels at the St. Marks Place residences and Central Avenue residences south of the garage entrance are in the marginally acceptable range. The St. George Library Center and Central Avenue residences located north of the garage entrance are at an acceptable level for noise during the a.m. and p.m. peak periods and at a marginally acceptable level during the midday peak period. Noise exposure levels at the Slosson Terrace residences fluctuate from marginally acceptable during the a.m. peak hour to acceptable during the midday and p.m. peak periods (refer to Table 14-2 for noise exposure guidelines). No-Build Condition Under the No-Build Condition, the Proposed Project would not occur and the day-to-day operations at the Project Site would remain unchanged. An increase in background traffic would influence future noise levels in the area without the Proposed Project. No new stationary sources of noise would be introduced to the Project Site under the No-Build Condition. Noise levels for the No-Build Condition, calculated based on CEQR Technical Manual methodologies, and presented below in Table 14-6. Under the No-Build Condition, noise exposure levels would remain similar to the existing condition with all noise sensitive resources in the marginally acceptable range with some levels in the acceptable range during the a.m. and p.m. peak periods. Build Condition Mobile Source Impact Analysis The noise impact assessment for the Proposed Project was performed in accordance with the CEQR Technical Manual guidelines to identify whether the potential exists for the Proposed Project to generate a significant noise impact at a receptor, or be significantly affected by high ambient sound levels. 187 For vehicular noise, if the PCE values are at least doubled (i.e., a 100 percent increase) between the No-Build and Build conditions along any affected roadway link, then a detailed noise analysis must be performed. A doubling of PCEs would increase sound levels by 3.0 dba. Consequently, if a doubling of PCEs does not occur, there would be no potential for significant adverse impacts, and further analysis would not be required. 185 CEQR Technical Manual, p. 3R-4. 186 U.S. Department of Transportation, Federal Highway Administration. FHWA Roadway Construction Noise Model User s Guide Final Report. January 2006. p.27. http://www.fhwa.dot.gov/environment/noise/rcnm/rcnm.pdf (February 11, 2008). 187 CEQR Technical Manual, p. 3R-18.
Dormitory Authority of the State of New York Page 14-8 The traffic anticipated to pass each receptor was calculated for the Existing, No-Build, and Build Conditions to determine the expected increase in PCE values (Refer to Table 14-5). The associated sound levels predicted for each time period at each site are shown in Table 14-6. Changes to the sound level are calculated using the following equation: Change in level (dba) = 10 log (PCE2/PCE1) where PCE 1 = the PCE total counted during noise monitoring, and, PCE2 = the PCEs calculated for the Existing, No-Build, or Build conditions (as shown in Table 14-5). This increase (or decrease) is then added to the sound level obtained during monitoring to estimate the Existing, No-Build, and Build sound levels associated with the respective traffic numbers described in Section 11, Traffic and Parking. Site Location Time 1 St. Marks Place Residences 2 3 Table 14-5. Predicted Peak-Hour PCEs Existing PCEs No-Build PCEs Build PCEs Percentage (%) Increase Between No- Build and Build A.M. 253 264 266 1% Midday 312 329 329 0% P.M. 376 397 459 16% A.M. 301 316 317 0% Midday 278 293 295 1% St. George Library and North of Garage Entrance P.M. 305 321 375 17% South of Garage Entrance A.M. 376 469 616 31% Midday 271 396 414 5% P.M. 384 437 580 33% A.M. 468 494 641 30% Midday 321 337 355 5% 4 Slosson Terrace Residences P.M. 299 315 458 45% Source: Jacobs Edwards and Kelcey, 2007 Table 14-6. Predicted Peak-Hour Sound Levels (L eq, dba) Site Location Time Existing Sound Level No-Build Sound Level Build Sound Level 1 St. Marks Place Residences 2 3 Increase Between No- Build and Build A.M. 62.9 63.1 63.2 0.1 Midday 63.8 64.1 64.1 0.0 P.M. 62.0 62.3 63.0 0.7 A.M. 60.5 60.7 60.8 0.1 Midday 63.2 63.5 63.5 0.0 St. George Library and North of Garage Entrance P.M. 60.0 60.3 61.0 0.7 South of Garage Entrance A.M. 62.7 63.7 65.0 1.3 Midday 62.8 64.7 64.9 0.2 P.M. 62.8 63.5 64.8 1.3 A.M. 63.9 64.2 65.4 1.2 Midday 64.6 64.8 65.1 0.3 4 Slosson Terrace Residences P.M. 61.3 61.6 63.4 1.8 Source: Jacobs Edwards and Kelcey, 2007
Dormitory Authority of the State of New York Page 14-9 The percentage increases in PCEs ranges from 0 to 45 percent, with the greatest increase occurring during the p.m. peak hour at the Slosson Terrace residences, with an increase of 45 percent. The Build Condition sound levels range between 60.8 and 65.4 dba, with increases of 0 to 1.8 dba. The highest sound levels of 64.8 to 65.4 dba occur at Central Avenue south of the garage entrance during all peak periods, and at Slosson Terrace during the a.m. and midday peak periods. The greatest increase, 1.8 dba, occurs during the p.m. peak period at Slosson Terrace. Since the greatest increase in PCEs would be less than the 100 percent increase threshold and the increase in sound levels would be less than 3.0 dba, the proposed courthouse would not have the potential for a significant noise impact. 188 Therefore, further detailed noise analyses are not required and no significant adverse mobile source noise impacts are expected as a result of the Proposed Project. Sound levels under the Build Condition would fall within the marginally acceptable category with acceptable sound exposure levels at the St. George Library and Central Avenue residences north of the garage entrance during the a.m. and p.m. peak periods. The parking garage is anticipated to cause minimal increases in sound levels over the existing use as surface parking. The monitored sound levels range from 59.9 to 64.5. The increase in vehicle movements on site would be approximately 35 percent, increasing this lowest monitored sound level to 61.2 dba and the highest monitored sound level to 65.8. This increase of 1.3 dba would be less than the 3.0 dba impact criteria for the highest-monitored sound level and less than the 5.0 dba impact criteria for the lowest monitored sound level. Additionally, the sound levels of 61.2 and 65.8 would be less than the New York City Noise Code standard of 70 dba. No significant mobile source noise impacts are expected from the proposed parking garage. Stationary Source Impact Analysis The lowest existing daytime sound levels of residences near the proposed courthouse is 59.9 dba. According to the CEQR Technical Manual, at this sound level an increase of 5.0 dba or more, to 64.9 dba would be considered a significant impact. Under the New York City Noise Code, the average hourly noise level emanating from the Project Site cannot exceed 70.0 dba (Leq). To satisfy both of these standards, sound levels emanating from the Project Site should not exceed 64.9 dba. Stationary source noise sources associated with the courthouse would include heating, ventilation and air conditioning ( HVAC ) equipment on the roof of the 5-story building. A quantitative analysis of HVAC equipment was not performed because detailed manufacturing specifications for this equipment would not become available until construction documents are finalized. However, the HVAC equipment would be positioned to minimize sound levels at the neighboring residences and ensure New York City Noise Code compliance. Therefore, no significant stationary source noise impacts are expected from the proposed courthouse. 188 CEQR Technical Manual, p. 3R-8.
Dormitory Authority of the State of New York Page 14-10 Noise Exposure To assess the impact to the proposed courthouse from the neighboring noise sources, the sound levels are compared to the Noise Exposure Guidelines described in Table 14-2 above. These guidelines analyze sound levels using the L 10 descriptor. The existing daytime sound levels near the Project Site range between 62.5 and 66.8 dba (L 10 ). These sound levels fall within the marginally acceptable range of 65.0 to 70.0 dba (L 10 ) for General External Exposure. These sound levels are made up of noise from existing noise sources including vehicular traffic, pedestrian noise, and HVAC equipment associated with neighboring buildings. The window design of the proposed courthouse was not quantitatively assessed because manufacturing specifications are not available until the construction documents for the project are finalized. Mitigation The Proposed Project would not result in significant adverse mobile source noise impacts. Sound levels associated with traffic noise would also not cause a significant noise impact, as levels would not increase above the CEQR standards of 3.0 dba. Therefore, no significant adverse noise impacts from the Proposed Project are predicted and no mitigation is required.