Chapter 10: Noise A. INTRODUCTION

10-1

Chapter 10: Noise

A. INTRODUCTION This chapter assesses the potential noise effects resulting from construction and operation of the proposed Route 9A Project alternatives.

The proposed project is a Type I project, as defined in 23 CFR 772, “Procedures for Abatement of Highway Traffic Noise and Construction Noise” and the NYSDOT Environmental Procedures Manual, “Noise Analysis Policy.” The Federal Highway Administration (FHWA) has established noise analysis procedures for federally aided highway projects, such as the reconstruction of Route 9A, to provide guidance and criteria for noise studies and noise abatement measures. FHWA requires (1) identification of existing activities, developed lands, and undeveloped lands for which development is planned, designed, and programmed that may be affected by noise from the highway; (2) measurement of existing noise levels; (3) prediction of existing and future traffic noise levels; (4) determination of traffic noise impacts; (5) examination and evaluation of alternative noise abatement measures to reduce or eliminate noise impacts; (6) analysis of construction noise; and (7) coordination with local officials.

B. NOISE FUNDAMENTALS AND TERMINOLOGY

• Decibel—Noise is measured in units called decibels. A 1-decibel change in noise is about the smallest change detectable by the human ear under ideal laboratory conditions. Outside a laboratory, only a change of about 3 decibels or more can be easily detected without the use of instruments. A change of more than 5 decibels is an appreciable change in a community's noise level. A 10-decibel increase is considered large and represents a doubling of loudness. (For example, 50 decibels sounds twice as loud as 40 decibels.)

• A-weighted decibel—Sound measured by scientific instruments is adjusted to correspond to human hearing; it is filtered to reduce the strength of very low- and high-pitched sounds. This adjusted unit is known as the A-weighted decibel, or dBA. Table 10-1 lists typical noise levels, in dBA, generated by different sources.

• Leq(1)—The Leq(1) is an hourly measure representing a constant noise level with the same sound energy as the actual fluctuating noise sources recorded during the same hourly period. In accordance with FHWA regulations and New York State Department of Transportation (NYSDOT) policy, the basic unit of noise used in this study is the dBA Leq(1).

Route 9A Project FSEIS

10-2

Table 10-1Common Noise Levels

Sound Source (dBA) Military jet, air raid siren 130 Amplified rock music 110 Jet takeoff at 500 meters 100 Freight train at 30 meters Train horn at 30 meters 90 Heavy truck at 15 meters Busy city street, loud shout 80 Busy traffic intersection Highway traffic at 15 meters, train 70 Predominantly industrial area 60 Light car traffic at 15 meters, city or commercial areas or residential areas close to industry

Background noise in an office 50 Suburban areas with medium density transportation Public library 40 Soft whisper at 5 meters 30 Threshold of hearing 0 Note: A 10 dBA increase in level appears to double the loudness, and a 10

dBA decrease halves the apparent loudness. Sources: Cowan, James P. Handbook of Environmental Acoustics.

Van Nostrand Reinhold, New York, 1994. Egan, M. David, Architectural Acoustics. McGraw-Hill Book Company, 1988.

C. NOISE ANALYSIS METHODOLOGY The methods used in determining noise impacts for this project are in accordance with FHWA regulations and NYSDOT policy. The following methods were used to determine existing noise levels, predict future noise levels, and assess potential noise impacts resulting from the proposed project:

• Existing land uses were established for the project area;

• A noise measurement program was conducted to determine existing noise levels;

• The proposed project for each alternative was modeled utilizing the FHWA Traffic Noise Model (TNM 2.5). The existing condition was also modeled utilizing TNM and compared to the field measurements, in order to verify the accuracy of the inputs for the noise modeling;

Chapter 10: Noise

10-3

• Predicted design-year noise levels were compared to the existing noise levels and the FHWA Noise Abatement Criteria (NAC) to determine if any noise impacts would result from each alternative; and

• Noise abatement measures were examined and evaluated at potentially impacted locations.

POTENTIALLY AFFECTED LAND USES

The land uses that may be affected by noise from the Route 9A project include community facilities and public outdoor areas, residences, and, to a lesser extent, office and other commercial buildings. All such land uses west of Route 9A to the Hudson River, and within two to four blocks east of Route 9A, were identified. Existing land uses, as well as future sites that are currently planned, designed, and programmed for construction, such as the proposed World Trade Center (WTC) Memorial, were included. (See Chapter 4, “Land Use, Public Policy, and Neighborhood Character,” for further details on the memorial).

NOISE MEASUREMENT PROGRAM

Noise levels were measured at 14 locations adjacent to the project site to determine existing conditions. The selected receptor sites are locations where the maximum changes from project-generated traffic increases or roadway alignment changes would be expected to occur and are therefore, the locations with the highest potential for project impacts. Measurements were taken at ground level, where project noise would be loudest, with a microphone height of 5 feet, representing average ear level. The measurement sites and the boundaries of the noise study area are illustrated in Figure 10-1.

All measurements were performed using Type I instrumentation. Twenty-minute noise measurements were obtained at each receptor site during the AM and PM peak periods. Precision Sound Level Meters (SLM) were used for the field measurements. The SLMs meet or exceed the requirements set forth in the ANSI S1.4-1983 Standards for Type I quality and accuracy. Acoustical calibrators were used to calibrate the SLMs before and after each measurement period. The SLMs were operated on the A-weighting network and slow-meter response, as recommended by the manufacturer. Measurements were not collected if roadway pavement was wet, or if wind speed exceeded 12 miles per hour. A porous windscreen was used on each SLM, during all measurement periods.

FHWA regulations, and NYSDOT policy based on these regulations, require prediction of the worst hourly traffic-generated noise impacts for a project's design year. Based on noise measurements in the study area and on preliminary traffic noise computations in the AM and PM peak periods, the worst-case noise hour for the Route 9A project was determined to be the 8 to 9 AM morning peak traffic hour. This is consistent with the findings of the 1994 Final Environmental Impact Statement (FEIS).

Existing noise levels were measured once during the AM peak period and once during the PM peak period. For this study area, and in general for urban settings, it is usually not necessary to measure noise levels more than once during each peak period. This is because peak period traffic volumes are near capacity and the small day to day variation in these volumes would not be sufficient to cause a meaningful variation in noise levels. By contrast, in suburban settings, where peak period traffic volumes can vary significantly from day to day, it is sometimes necessary to measure noise levels during a given peak period more than once, until two measurements that agree within 3 dBA are obtained.

BatteryPark

VietnamVeterans

Plaza

FoleySquare

SouthbridgeTowers

CityHallPark

Battery Pl.

Whitehall St.

Broad St.

Water S

t.

South

St.

Pear

l St

.Beaver S

t.

Old Slip

Wall St.

New

St.

Pine St.

Broa

dway

Nas

sau

St.

John St.

Maiden Lane

Liberty St.

Albany St.

Thames St.

Batte

ry P

l.

Sout

h En

d Av

e.

Fulton St.Ann St.

Beekman St.

Fulton St.

Park R

ow

Chu

rch

St.

Gol

d St

.

Vesey St.

Barclay St.

Murray St.

Warren St.

Chambers St.

W. B

road

way

Reade St.

Duane St.

Thomas St.

Worth St.

Greenwich St.

Harrison St.

Leonard St.

Park Row

Route 9A / West St.

Greenwich St.

Washington St.

Chu

rch

St.

Exchange St.

First Pl.

Third Pl.

Pearl S

t.State St.

CedarSt.

Nass

au S

t.

Maiden Lane

Rector St.

St.

Spruce St.

Willi

am S

t.

Park Pl.

Vesey St.

Warren St.

Chambers St.N

orth

End

Ave

.

River Terrace

Cen

tre S

t.

Rt. 9A

HUDSON

R IV E R

55WaterStreet

NewYorkPlaza

ChaseManhattan

Plaza

Pear

l St

.

Wat

er S

t.

BatteryBatteryParkParkCityCity

BatteryParkCity

Project Area Corridor

Lower Manhattan Office Market Subarea Boundary

Noise Receptor Location

N

1

1

11

2

12

3

13

4

5

6

78

9

10

SCALESCALESCALE

1000 FEET0

FIGURE 10-1Noise Receptor Locations

14

9/30/04


10-4

TRAFFIC NOISE PREDICTION MODEL

The FHWA Traffic Noise Model, TNM 2.5, was used for traffic noise predictions.1 TNM calculates the noise contribution of each roadway segment to a given noise receptor. The noise from each vehicle type is determined as a function of the reference energy-mean emission level, corrected for vehicle volume, speed, roadway grade, roadway segment length, and source-receptor distance. Further adjustments needed to model the propagation path include shielding provided by rows of buildings, the effects of different ground types, source and receptor elevations, and effect of any intervening noise barriers. The program then repeats this process for all roadway segments, summing their contributions to generate the predicted noise level at the given receptor. The same procedure is repeated for all other receptors in the study area.

MODELING TO PREDICT IMPACTS FROM CONSTRUCTION ACTIVITIES

Noise from construction activities was estimated following the methodologies set forth in the FHWA Technical Advisory T 6160.2, “Analysis of Highway Construction Noise.” The procedure uses the following equation to calculate noise levels from operation of a single piece of construction equipment.

Leq = E.L. + 10 log (U.F.) – 20 log (D1/D2) – Ashielding

where:

Leq is the noise level at a receiver of the equipment over a specified time period;

E.L. is the noise emission level of the equipment at a reference distance of 50 feet;

Ashielding is the attenuation due to shielding;

D1 is the distance from the receiver to the piece of equipment;

D2 is the reference distance at which equipment noise level data is known; and

U.F. is a usage factor that accounts for the fraction of time that the equipment is in use over the specified time period.

The combined noise resulting from all pieces of equipment operating during the same time period was obtained by adding the Leq values for the different pieces of equipment. The 1-hour Leq(1) values were calculated assuming appropriate usage factors for the specified time periods, for each element of construction.

D. NOISE IMPACT CRITERIA

OPERATIONAL TRAFFIC NOISE IMPACT CRITERIA

In accordance with FHWA regulations and NYSDOT policy, a traffic noise impact occurs when either one of the following conditions is met: (1) the predicted traffic noise levels associated with a project alternative would approach or exceed the FHWA established noise abatement criteria; or (2) the predicted traffic noise levels would substantially exceed the existing noise levels. These criteria are discussed in greater detail below.

1 FHWA Highway Traffic Noise Prediction Model, TNM version 2.5, Federal Highway Administration,

Washington, D.C., April, 2004.

Chapter 10: Noise

10-5

FHWA NOISE ABATEMENT CRITERIA

A highway project is considered to cause a traffic noise impact if any one of five FHWA noise abatement criteria is approached (within 1 dBA) or exceeded. Each of these noise abatement criteria (designated as Category A to E) applies to a specific land use adjacent to a highway, as shown in Table 10-2. Categories A through D apply to exterior noise levels, while category E applies to interior noise levels.

Table 10-2FHWA Noise Abatement Criteria

Hourly A-Weighted Sound Levels (dBA)

Activity Category Leq(1) Description of Activity Category

A 57 Exterior

Lands on which serenity and quiet are of extraordinary significance and serve an important public need and

where the preservation of those qualities is essential if the area is to continue to serve its intended purpose.

B 67 Exterior

Picnic areas, recreation areas, playgrounds, active sports areas, parks, residences, motels, hotels, schools,

churches, libraries, and hospitals.

C 72 Exterior

Developed lands, properties, or activities not included in Active Categories A or B, above.

D None Undeveloped lands.

E 52 Interior

Residences, motels, hotels, public meeting rooms, schools, churches, libraries, hospitals, and auditoriums.

Note: Leq(1) means hourly A-weighted equivalent sound level, in dBA.

For parks and open space areas along Route 9A where lowered noise levels would be of benefit, potential outdoor noise impacts were assessed, using the FHWA Activity Category B noise abatement criterion—for the WTC Memorial, the Battery Park City Ballfields, and Washington Market Park.

For all other properties in the Route 9A noise analysis study area, outdoor uses where lowered noise levels would be of benefit are rare. Therefore, for these properties, potential noise impacts resulting from the proposed Route 9A project were assessed indoors. To facilitate this impact assessment, the interior noise abatement criterion (52 dBA Leq(1)) was translated to its corresponding exterior noise levels, as shown in Table 10-3. (See Appendix H, “Noise,” of the 1994 FEIS for further details). The exterior noise levels shown in Table 10-3 are those that would result in an indoor noise level of 52 dBA Leq(1) after the noise enters the building through its window/wall structure and is thus attenuated.

Properties with indoor uses in the Route 9A noise analysis study area generally fell into Building Type categories 2 or 4, with a few instances of Building Types 1 and 6. In most cases, closed windows were assumed because, one or more of the following criteria applied to the buildings analyzed: (1) the building's windows are designed not to open; (2) the building is centrally air conditioned; and/or (3) essentially all rooms in the building have window air conditioning units or through-the-wall units under the windows.


10-6

Table 10-3Translation of the FHWA Category E Interior Noise Abatement Criterion

To Its Corresponding Exterior Noise Levels

Building Noise Insulation

Corresponding Exterior Noise Level

Leq(1)

Building Type

Typical Building Description

FHWA Category E

Interior Noise Abatement

Criterion Leq(1) Windows

Open Windows Closed

Windows Open

Windows Closed

1 Public Schools1 52 dBA 7 dBA 15 dBA 58 dBA 66 dBA 2 Old, large apartment

buildings and hotels 52 dBA 7 dBA 20 dBA 58 dBA 71 dBA

3 Apartment buildings and hotels with exterior sliding glass doors

52 dBA 10 dBA 23 dBA 61 dBA 74 dBA

4 All other apartment buildings and hotels, plus colleges

52 dBA 10 dBA 25 dBA 61 dBA 76 dBA

5 Brownstones 52 dBA 15 dBA 23 dBA 66 dBA 74 dBA 6 Places of worship 52 dBA 15 dBA 25 dBA 66 dBA 76 dBA

Note: 1) Measurements conducted by AKRF, Inc. in April and July 2004 indicate that the actual building noise insulation with closed windows is approximately 26 dBA for Stuyvesant High School and P.S. 234, and 31 dBA for P.S. 89.

2) These exterior noise abatement criteria levels incorporate the “approach or exceed” 1 dBA reduction, e.g. 52 dBA + 7 dBA – 1dBA = 58 dBA,.

SUBSTANTIAL EXCEEDANCE OF EXISTING NOISE LEVELS

Noise impacts also occur when the predicted future traffic noise levels from a roadway project substantially exceed the existing noise levels. NYSDOT defines a substantial noise increase as an increase of 6 decibels or more above existing noise levels. Typically, such an increase could occur if traffic volumes quadrupled or the distance between the receptor and the source decreased by a factor of four. A combination of a less than fourfold traffic increase with a less than fourfold decrease in source-receptor distance could also increase noise levels by 6 decibels.

It is important to note that noise impacts could occur even when a Build alternative would result in lower noise levels than the No Build Alternative. FHWA and NYSDOT define an impact by comparison to the existing noise levels and to the noise abatement criteria discussed above—not by comparison to the No Build Alternative. Based on these impact criteria, therefore, and as a condition to obtaining FHWA funds, every effort must be made to obtain substantial noise reduction at impacted locations, regardless of No Build Alternative noise levels, provided that such noise abatement is feasible and reasonable.

CONSTRUCTION NOISE IMPACT GUIDANCE LEVELS

According to FHWA regulations and NYSDOT policy, a construction noise impact will not normally occur at levels under 85 dBA Leq(1).

Chapter 10: Noise

10-7

E. EXISTING CONDITIONS

POST-SEPTEMBER 11, 2001 BASELINE

MEASURED NOISE LEVELS

Fourteen noise receptor locations, shown in Figure 10-1, were selected for noise measurements. The range of land uses represented by these 14 noise receptors include: the future site of the WTC Memorial, Stuyvesant High School, P.S. 234, P.S. 89, residential and commercial office buildings, institutional buildings, hotels, and parks. The noise level measured at each of the noise receptors is representative of the noise level at all land uses in the immediate vicinity of that receptor.

At each receptor, measurements were made during the AM and PM peak periods. As described previously, the worst-case noise hour for the Route 9A project was determined to be 8 to 9 AM. Measured Leq(1) noise levels for the AM peak period are shown in Table 10-4. As shown in the table, all of the measured noise levels are relatively high and reflect the high level of vehicular activity in the study area.

NOISE MODEL VALIDATION

Although TNM has been shown to be an accurate predictor of noise levels for most situations, the model was validated for use in this study by comparing measured and modeled predicted noise levels.

Using the inputs for the traffic volumes, speeds, roadway alignments, ground reflections, and existing buildings, the TNM model was run to predict the AM peak hour traffic noise levels for the existing condition. A difference of 3 dBA or less between the modeled noise levels and measured noise levels indicates that the TNM model can be used with confidence. Table 10-4 shows that all of the modeled noise levels are within 3 dBA of the measured values. In general, the modeled noise levels are lower than the measured noise levels. This is to be expected since extraneous sources of noise (e.g., aircraft flyovers, car horns, construction activities, etc.) are not included in TNM model calculations.

F. PROBABLE IMPACTS OF PROJECT ALTERNATIVES

CONSTRUCTION NOISE IMPACTS

Construction activities for the proposed Route 9A project have the potential to cause perceptible increases in existing noise levels at certain locations within the Route 9A noise study area. Construction-related noise levels would depend on several factors, including equipment and construction methods employed; distance between the construction noise source and the receptor; and time of day. Typical noise levels for construction equipment that may be used during construction of the proposed project, measured at a nominal distance of 50 feet from the noise source, are presented in Table 10-5. Using this data as a starting point, and taking into account the proposed project’s construction plan and schedule, as well as site specific conditions (e.g., building locations and acoustical shielding effects), peak hour project-generated construction noise levels were estimated, and are presented in Table 10-6.


10-8

Table 10-4Existing Noise Levels (in dBA)

Site Location Land Use(s) Represented

Measured Leq(1) Noise Level

Modeled TNM Leq(1)

Noise Level Difference

1 Memorial park at WTC Site Park 67* 73** N/A**

2 Route 9A between Carlisle and Albany Streets Hotel & Residential 75 75 0

3 Albany Street between South End Avenue and Route 9A Residential & Office 71 71 0

4 Albany Street between Route 9A and Washington Street Hotel & Residential 72 72 0

5 Route 9A between Liberty and Vesey Streets Office 69 71 2

6 Vesey Street between North End Avenue and Route 9A Hotel & Office 71 70 -1

7 Route 9A between Barclay and Murray Streets Office & Institutional 79 78 -1

8 Murray Street between North End Avenue and Route 9A Hotel & Park 72 70 -2

9 Murray Street between Greenwich Street and West Broadway Residential and Office 70 70 0

10 Warren Street between Greenwich Street and Route 9A

Institutional & Residential 67 68 1

11 Route 9A between Warren and Chambers Streets Institutional 72 74 2

12 Corner of Route 9A and Murray Street Park 73* 75 2

13 Barclay Street between Route 9A and Greenwich Street Office 66* 65 -1

14 Route 9A between W. Thames Street and Third Place Residential 70 69 -1

Note: * These measurements were conducted by The Louis Berger Group in October 2003. All other measurements were

conducted by AKRF in December 2003. ** The existing noise level at Site 1 was measured below grade in the WTC bathtub. This measurement was dominated by

extraneous noise generated by construction activities at the WTC Site, and was therefore not used to validate the existing conditions noise model. The existing modeled noise level shown for Site 1 corresponds to a future at-grade receptor located adjacent to Route 9A, in the planned Memorial Park at the WTC Site. Although the Memorial Park will not be completed until after 2006, this existing modeled noise level is presented for informational purposes.

Chapter 10: Noise

10-9

Table 10-5Construction Equipment Noise Emission Levels (in dBA)

Equipment Typical Noise Level (dBA)

50 feet from source Air compressor 81

Backhoe 80 Ballast Equalizer 82 Ballast Tamper 83

Bulldozer 85 Compactor 82

Concrete Mixer 85 Concrete Pump 82

Concrete Vibrator 76 Crane, Derrick 88 Crane, Mobile 83

Excavator1 80 Generator 81

Grader 85 Impact Wrench 85 Jack Hammer 88

Loader 85 Paver 89

Pile Driver (Impact) 101 Pile Driver (Sonic) 96 Pneumatic Tool 85

Pump 76 Rail Saw 90 Rock Drill 98

Roller 74 Saw 76

Scarifier 83 Scraper 89 Shovel 82

Slurry Desanding and Mixing Plant1 85 Spike Driver 77 Tie Cutter 84

Tie Handler 80 Tie Inserter 85

Truck 88 Welding Machine2 70

Notes: 1 Noise levels derived from similar equipment listed in Transit Noise and Vibration Impact

Assessment. 2 Noise level obtained from Croton Water Treatment Plant EIS (Month, Year). Values do not incorporate potential noise reduction measures that may be included in the Construction Noise Management Plan. (Refer to Section G, “Noise Abatement.”) Sources: Except as otherwise noted, source of equipment noise levels is the FTA guidance

document Transit Noise and Vibration Impact Assessment (April 1995).


10-10

Table 10-6Maximum Noise Levels During Route 9A Construction without Abatement Measures

(in dBA)

Receptor Site Location

NYSDOT Guidance

Level Leq(1)

At-Grade Alternative1

Leq(1)

Exceeds NYSDOT Guidance

Level?

Short Bypass Alternative1

Leq(1)


Level? 1 Memorial Park at WTC Site2 85 N/A N/A N/A N/A

2 Route 9A between Carlisle Street and Albany Street 85 84 No 83 No

3 Albany Street between South End Avenue and Route 9A 85 73 No 76 No

4 Albany Street between Route 9A and Washington Street 85 69 No 73 No

5 Route 9A between Liberty Street and Vesey Street 85 87 Yes 92 Yes

6 Vesey Street between North End Avenue and Route 9A 85 83 No 86 Yes

7 Route 9A between Barclay Street and Murray Street 85 89 Yes 86 Yes

8 Murray Street between North End Avenue and Route 9A 85 71 No 76 No

9 Murray Street between Greenwich Street and West Broadway 85 69 No 67 No

10 Warren Street between Greenwich Street and Route 9A 85 65 No 63 No

11 Route 9A between Warren and Chambers Streets 85 73 No 72 No

12 Corner of Route 9A and Murray Street 85 81 No 83 No

13 Barclay Street between Route 9A and Greenwich Street 85 76 No 73 No

14 Route 9A between W. Thames Street and Third Place 85 72 No 74 No

Notes: 1 Leq(1) is the predicted hourly-equivalent noise level during the peak construction hour. 2 Receptor 1, the Memorial Park at the WTC Site, is scheduled for completion in 2009.

It would not be operational in 2006 and would therefore not be impacted by Route 9A construction noise.

The project-generated construction noise levels presented in Table 10-6, and discussed in greater detail in the text that follows the table, indicate that without the development and implementation of noise abatement measures, the proposed Route 9A construction operations would result in adverse noise impacts at sensitive receptors immediately adjacent to the project site. These impacts would continue for a considerable period of time, and could occur during nighttime and weekend hours, as well as during weekdays. Possible abatement measures to reduce these impacts are discussed later in this chapter. The cumulative effects of Route 9A construction taking place concurrently with construction of the other Lower Manhattan Recovery Projects is discussed in Chapter 16, “Cumulative Effects.”

The project-generated construction noise levels shown in Table 10-6 are based on the project’s current construction plan and schedule. As design of the project advances, certain details of the construction plan and schedule may be modified, e.g. construction staging, the selection of particular pieces of construction equipment, and/or their placement within the project site. Such changes are not expected to alter the magnitude and range of construction noise levels and

Chapter 10: Noise

10-11

impacts presented in Table 10-6, but rather to change where and when these impacts may occur within the project site and its immediate vicinity. To ensure that construction noise impacts are mitigated to the greatest extent possible, noise mitigation measures would be applied at all locations and during all time periods during which impacts occur. Investigation of effective and feasible noise mitigation measures, beyond those that have already been identified, would also be ongoing for the duration of the construction period.

AT-GRADE ALTERNATIVE

For the At-Grade Alternative, the project-generated construction noise levels would exceed the NYSDOT guidance level of 85 dBA Leq(1) at receptor sites 5 and 7. At receptor site 5, exceedances would occur for one and one-half months, during phase 13 of construction stage 2. At receptor site 7, exceedances would occur for 2 ½ months, during phase 15 of construction stage 2.

SHORT BYPASS ALTERNATIVE

For the Short Bypass Alternative, the project-generated construction noise levels would exceed the NYSDOT guidance level of 85 dBA Leq(1) at receptor sites 5, 6 and 7. At receptor site 5, exceedances would occur for a total of eight months, during phases 16, 17, 18, 20, 21, 24, and 29, of construction stage 2. At receptor sites 6 and 7, exceedances would occur for a total of three months, during phases 20 and 21, of construction stage 2.

CONSTRUCTION VIBRATION IMPACTS

Construction activities associated with the Route 9A project would result in varying degrees of ground vibration depending on the stage of construction, the equipment and construction methods employed, and the distance from the construction to buildings and vibration sensitive structures. Table 10-7 shows typical construction equipment and vibration levels at distances varying from 5 feet to 50 feet.

To account for potential vibration impacts that may result from construction of the project, all historic buildings or sites located within 90 feet of the construction zone, which has the same extents under both Build Alternatives as well as the No Action Alternative, were identified (see Chapter 6, “Cultural Resources”). There are seven such buildings or sites: the Barclay-Vesey Building, the WTC Site, 90 West Street, the New York Evening Post Building at 75 West Street, 40 Rector Street Building, the Frasch Building at 56 West Street, and the Crystal Building at 47-49 West Street.

Under the Short Bypass Alternative, three of these properties would be located within 90 feet of the excavation zone for the bypass—the Barclay-Vesey Building, the WTC Site, and 90 West Street.

Under the At-Grade Alternative, excavation for a bypass would not take place. However, the three properties mentioned above would be located within 90 feet of the excavation zone for other project components, such as slurry walls, and various elements of the Permanent WTC PATH Terminal Project and the WTC Memorial and Redevelopment Project to be


10-12

Table 10-7Typical Vibration Levels vs. Distance from Source

Peak Particle Velocity (inches per second) Equipment 5 feet 10 feet 20 feet 30 feet 40 feet 50 feet

Pile driver (typical impact) 7.20 2.55 0.90 0.49 0.32 0.23 Clam shovel drop (slurry wall) 2.26 0.80 0.28 0.15 0.10 0.07 Hydromill slurry wall in soil 0.09 0.03 0.01 0.01 0.00 0.00 Hydromill slurry wall in rock 0.19 0.07 0.02 0.01 0.01 0.01 Large bulldozer 1.00 0.35 0.12 0.07 0.04 0.03 Caisson drilling 1.00 0.35 0.12 0.07 0.04 0.03 Loaded trucks 0.85 0.30 0.11 0.06 0.04 0.03 Jackhammer 0.39 0.14 0.05 0.03 0.02 0.01 Small bulldozer 0.03 0.01 0.00 0.00 0.00 0.00

constructed under Route 9A. Specifically, slurry walls would be constructed in front of the Barclay-Vesey Building and 90 West Street. The PATH pedestrian concourse and a slurry wall on the west side of Route 9A would be constructed adjacent to the WTC Site. Portions of the river water intake and discharge lines, for the WTC Site, would also be constructed under Route 9A adjacent to the WTC Site.

Due to the construction activities described above, construction vibration levels at the Barclay-Vesey Building, the WTC Site, and 90 West Street are expected to be similar under the Short Bypass and At-Grade Alternatives.

To avoid damage to the historic structures described above, a construction protection plan would be developed and mitigation measures would be implemented as described in Section G, “Noise and Vibration Abatement.”

Construction vibration impact criteria will be specified in the Route 9A Special Note for Building Condition Survey and Vibration Criteria, which is currently being developed by NYSDOT in consultation with SHPO, and which will incorporate the requirements specified in the “New York City Department of Buildings Technical Policy and Procedure Notice #10/88.” Allowable vibration intensities, expressed as maximum peak particle velocities, will range from 0.5 to 5.0 cm/sec, depending on which adjacent structures are affected and their location relative to Route 9A construction activities.

OPERATIONAL TRAFFIC NOISE IMPACTS (2025)

Operational traffic noise levels at the 14 receptors shown in Figure 10-1 were modeled using TNM for the No Action Alternative, the At-Grade Alternative, and the Short Bypass Alternative, for the project design year, 2025. Using the modeled noise levels for these 14 receptors, noise levels were predicted for all properties within the noise study area. Potential noise impacts were assessed based on the FHWA and NYSDOT impact criteria described in Section D of this chapter.

A comparison of the number of noise impacts expected to occur under the different alternatives is presented in Table 10-8. It should be noted that for the majority of the additional dwelling units that would be impacted under the At-Grade Alternative as compared to the No Action or Short Bypass Alternatives, the difference in noise levels between the three alternatives is

Chapter 10: Noise

10-13

Table 10-8 Number of Properties Approaching or Exceeding the Noise Abatement Criteria

Operational Traffic Noise (2025) No Action Alternative At-Grade Alternative Short Bypass Alternative

FWHA Activity Category B (Outdoor uses) 6 6 6

FWHA Activity Category E (Indoor uses)

Existing Dwelling Units 77 272 52

Future Dwelling Units 103 103 103

Commercial and Institutional Buildings 10 11 4

between 0.3 and 1.8 dBA. Due to the rounding of noise levels to the nearest decibel, many of these dwelling units are impacted under the At-Grade Alternative, but not under the No Action and Short Bypass Alternatives. Figures and tables showing predicted noise levels at all properties within the noise study area are included in Appendix G, “Noise Analysis.”

NO ACTION ALTERNATIVE

Although noise impacts do not, by definition, apply to the No Action Alternative, future predicted noise levels for the No Action Alternative are provided for informational purposes. Table 10-9 shows a comparison of Leq(1) noise levels for the No Action Alternative with Existing Leq(1) noise levels. The maximum increase in noise level at any of the 14 modeled receptors under the No Action Alternative relative to existing conditions will be 3 dBA.

Table 10-9 No Action Noise Levels (in dBA)

Site TNM Modeled Existing Leq(1)

TNM Modeled No Action Leq(1) Increment

Substantial Exceedance?

1 73 73 0 0 2 75 76 1 No 3 71 71 0 No 4 72 73 1 No 5 71 72 1 No 6 70 72 2 No 7 78 79 1 No 8 70 72 2 No 9 70 70 0 No 10 68 70 2 No 11 74 75 1 No 12 75 76 1 No 13 65 68 3 No 14 69 70 1 No

Note: Site 1 is a future noise receptor located adjacent to Route 9A, in the at-grade portion of the planned Memorial Park at the WTC Site. Although the Memorial Park will not be completed until 2009, the existing modeled noise level at this location is presented for informational purposes.


10-14

The increase in noise level at any of the properties within the noise study area under the No Action Alternative relative to existing conditions is expected to be 3 dBA or less, based on the calculated maximum increase of 3 dBA for the 14 modeled receptors.

AT-GRADE ALTERNATIVE

Table 10-10 shows a comparison of Leq(1) noise levels for the At-Grade Alternative with existing Leq(1) noise levels. The maximum increase in noise level at any of the 14 modeled receptors under the At-Grade Alternative, relative to existing conditions, would be 4 dBA; therefore, the NYSDOT substantial exceedance impact threshold of 6 dBA would not be met at any of the 14 modeled receptor locations.

Table 10-10 At-Grade Alternative Noise Levels (in dBA)


TNM Modeled At-Grade Alternative Leq(1) Increment

Substantial Exceedance?

1 73 73 0 0

2 75 76 1 No

3 71 72 1 No 4 72 72 0 No 5 71 72 1 No 6 70 72 2 No 7 78 79 1 No 8 70 72 2 No 9 70 70 0 No

10 68 72 4 No 11 74 76 2 No 12 75 76 1 No 13 65 68 3 No 14 69 71 2 No


The increase in noise level at any of the properties within the noise study area under the At-Grade Alternative relative to existing conditions is expected to be 4 dBA or less, based on the calculated maximum increase of 4 dBA for the 14 modeled receptors. Therefore, it is expected that the NYSDOT substantial exceedance impact threshold of 6 dBA would not be met at any property within the noise study area for the At-Grade Alternative.

SHORT BYPASS ALTERNATIVE

Table 10-11 shows a comparison of Leq(1) noise levels for the Short Bypass Alternative with Existing Leq(1) noise levels. The maximum increase in noise level at any of the 14 modeled receptors under the Short Bypass Alternative, relative to existing conditions, would be 4 dBA; therefore, the NYSDOT substantial exceedance impact threshold of 6 dBA would not be met at any of the 14 modeled receptor locations.

Chapter 10: Noise

10-15

The increase in noise level at any of the properties within the noise study area under the Short Bypass Alternative, relative to existing conditions, is expected to be 4 dBA or less, based on the calculated maximum increase of 4 dBA for the 14 modeled receptors. Therefore, it is expected that the NYSDOT substantial exceedance impact threshold of 6 dBA would not be met at any property within the noise study area for the Short Bypass Alternative.

Table 10-11 Short Bypass Alternative Noise Levels (in dBA)


TNM Modeled Short Bypass

Alternative Leq(1) Increment Substantial

Exceedance? 1 73 70 -3 No 2 75 73 -2 No 3 71 70 -1 No 4 72 70 -2 No 5 71 68 -3 No 6 70 72 2 No 7 78 75 -3 No 8 70 70 0 No 9 70 70 0 No 10 68 72 4 No 11 74 76 2 No 12 75 74 -1 No 13 65 66 1 No 14 69 69 0 No


It should be noted that the Short Bypass Alternative would include ventilation fans operating inside the bypass structure. These fans were analyzed to determine if they would contribute significantly to project-generated noise levels. Based on calculations that are detailed in Appendix G, the combined noise level of all the proposed fans was estimated to be approximately 57 dBA. This noise level is low compared to that generated by traffic on Route 9A. As a result, the ventilation fan noise would be masked by the Route 9A traffic noise, and the fans would not materially contribute to project-generated noise levels.

G. NOISE AND VIBRATION ABATEMENT

CONSTRUCTION NOISE AND VIBRATION ABATEMENT MEASURES

Construction contractors would also be required to comply with local laws and regulations regarding construction-related noise, including the Sections 103.02 and 107.1 of the NYSDOT Standard Specifications.

For the At-Grade Alternative, implementation of the construction noise abatement measures listed in Table 10-12 would eliminate all project-generated construction noise impacts. For the Short Bypass Alternative, implementation of the measures listed in Table 10-13 would eliminate all project-generated construction noise impacts. Table 10-14 shows project-generated construction noise levels with these abatement measures in place. The mitigated levels would not exceed the NYSDOT Leq(1) guidance level at any of the 14 receptor sites.


10-16

Table 10-12Summary of Construction Noise Abatement Measures

At-Grade Alternative

Phase Equipment Causing

Impact Mitigation Measures Potential Noise

Reduction (dBA) 13 Baur BG 12H Drill Place drill inside acoustical enclosure 18 1

15 Pickup Truck Driver Vibratory

Feasible Noise Control 10' - 12' temporary shielding barriers

13 2

9-103 Notes: 1 Engineering Section Report, Workers Compensation Board of British Columbia, Stuart Eaton, February 2000. 2 Noise Control, Measurement, Analysis and Control of Sound and Vibration, Charles E. Wilson, Krieger

Publishing Company, 1994 3 Noise Control & Research Laboratories, www.ncrl.net/bigdig.htm, measured noise reductions achieved with

acoustical curtain panels installed for the Central Artery Tunnel project in Boston, Massachusetts.

Table 10-13Summary of Construction Noise Abatement Measures

Short Bypass Alternative

Phase Equipment Causing

Impact Mitigation Measures Potential Noise

Reduction (dBA) 16 Concrete Mixer Truck Use quieter available equipment 10 2 17 Baur BG 12H Drill Place drill inside acoustical enclosure 18 1 18 Truck Dump - Semi Use quieter available equipment 13 2 20 Baur BG 12H Drill Place drill inside acoustical enclosure 18 1 21 Baur BG 12H Drill Place drill inside acoustical enclosure 18 1 24 Crane 35T Use quieter available equipment 13 2 29 Truck Dump - Semi Use quieter available equipment 13 2

Notes: 1 Engineering Section Report, Workers Compensation Board of British Columbia, Stuart Eaton, February 2000. 2 Noise Control, Measurement, Analysis and Control of Sound and Vibration, Charles E. Wilson, Krieger

Publishing Company, 1994

Although not required to eliminate construction noise impacts under either of the proposed alternatives, additional construction noise mitigation measures may be implemented as part of the Environmental Performance Commitments (EPCs) being developed and refined by the Lower Manhattan Construction Coordination Group (LMCCG), whose members include NYSDOT and sponsors of the other major Lower Manhattan Recovery Projects (LMDC, MTA NYCT, and PANYNJ). Table 10-15 shows the EPCs that relate to construction noise and vibration. Where relevant, references to the Route 9A Special Notes for (1) Building Condition Survey and Vibration Control, and (2) Noise Control are included. Additional site-specific noise abatement measures are discussed in Chapter 16, “Cumulative Effects.”

As described in Section F, “Construction Vibration Impacts,” seven historic buildings or sites are located within 90 feet of the construction zone under both proposed alternatives. To address potential vibration impacts to these structures, NYSDOT, in consultation with the State Historic Preservation Officer (SHPO) would develop a Construction Protection Plan based on the requirements specified in the “New York City Department of Buildings Technical Policy and Procedure Notice #10/88.” The following are potential measures to be implemented as part of the Construction Protection Plan.

Chapter 10: Noise

10-17

Table 10-14Maximum Noise Levels During Route 9A Construction with Abatement Measures

(in dBA)

Receptor Site Location

NYSDOT Guidance

Level Leq(1)

At-Grade Alternative1

Leq(1)


Level?

Short Bypass Alternative1

Leq(1)


Level? 1 Memorial Park at WTC Site2 85 N/A N/A N/A N/A

2 Route 9A between Carlisle Street and Albany Street 85 84 No 76 No

3 Albany Street between South End Avenue and Route 9A 85 72 No 69 No

4 Albany Street between Route 9A and Washington Street 85 69 No 65 No

5 Route 9A between Liberty Street and Vesey Street 85 84 No 84 No

6 Vesey Street between North End Avenue and Route 9A 85 83 No 79 No

7 Route 9A between Barclay Street and Murray Street 85 83 No 81 No

8 Murray Street between North End Avenue and Route 9A 85 68 No 69 No

9 Murray Street between Greenwich Street and West Broadway 85 67 No 60 No

10 Warren Street between Greenwich Street and Route 9A 85 63 No 56 No

11 Route 9A between Warren and Chambers Streets 85 72 No 65 No

12 Corner of Route 9A and Murray Street 85 77 No 76 No

13 Barclay Street between Route 9A and Greenwich Street 85 72 No 67 No

14 Route 9A between W. Thames Street and Third Place 85 72 No 67 No

Notes: 1 Leq(1) is the predicted hourly-equivalent noise level during the peak construction hour. 2 Receptor 1, the Memorial Park at the WTC Site, is scheduled for completion in 2009. It would not be operational in 2006 and would therefore not be impacted by Route 9A construction noise.

• NYSDOT, or its designee, would inspect and report on the current foundation and structural condition of the historic resources within the project’s APE.

• NYSDOT, or its designee, would establish a vibration monitoring program to measure vertical and lateral project-generated vibrations at historic structures within 90 feet of the construction zone. Technical and scheduling details of the vibration monitoring program would be developed as part of the project’s ongoing consultation with SHPO.

• NYSDOT, or its designee, would specify construction methods and monitor their implementation to ensure that project-related vibration levels do not cause structural damage to historic structures located within 90 feet of the proposed project’s construction zone.


10-18

Table 10-15EPCs and Proposed Implementation Plan

Technical Area Proposed Commitments Implementation Plan

Where practicable, schedule individual project construction activities to avoid or minimize adverse impacts.

As specified in the construction noise specifications currently being developed for the Route 9A Project by NYSDOT, where practicable, construction activities will be scheduled to avoid or minimize any adverse noise and vibration effects on sensitive receptors.

Coordinate construction activities with projects under construction in adjacent and nearby locations to avoid or minimize impacts.

Under the NYSDOT/NYCDOT Traffic Management Plan being developed in coordination with the LMCCG, adverse noise and vibration effects on sensitive receptors will be minimized through scheduling and routing of deliveries, coordination of street closures, and placement of truck/equipment staging areas.

Consider condition of surrounding buildings, structures, infrastructures, and utilities where appropriate.

Construction would comply with all provisions of the Route 9A Special Note for Building Condition Survey and Vibration Criteria currently being developed by NYSDOT, in consultation with SHPO. Issues to be addressed include:

• Identification of potentially affected buildings

• Scope and procedures for pre-construction building condition surveys

• Vibration criteria for affected structures • Contractor reporting requirements to

NYSDOT EIC

Noise and Vibration

Prepare contingency measures in the event established limits are exceeded.

Construction would comply with all noise control and enforcement provisions of the Route 9A Special Note for Noise Control currently being developed by NYSDOT. These include:

• Construction equipment noise emission limits and related certification

• Periodic noise compliance testing of construction equipment

• Operational requirements for construction equipment

• Provision of acoustic sheds, when required

• Spot noise level testing by the NYSDOT EIC

• Corrective actions in the event of non-compliance

• NYSDOT, or its designee, would issue “stop-work” orders to the construction contractor, as required, to prevent damage to historic structures, if any lateral or vertical vibration levels exceed the design criteria. Work would not restart until the steps proposed to stabilize and/or prevent further damage to the affected building were approved by SHPO.

Additional vibration control measures and practices may include routing project-related trucks and heavy equipment to avoid sensitive receptors, properly securing street decking over cut-and-cover excavation, and scheduling tasks to minimize the duration of vibration impacts.

Chapter 10: Noise

10-19

OPERATIONAL TRAFFIC NOISE ABATEMENT MEASURES

The measures described below were considered for abating the noise impacts expected to result from each of the Build Alternatives. Since none of these measures were found to be reasonable and feasible in the context of the goals and objectives of the proposed project, project-related noise impacts would remain unabated.

TRAFFIC MANAGEMENT

Traffic management measures that can reduce noise levels include prohibition of certain types of heavy vehicles, time restrictions on such vehicles, and reductions in roadway travel speed.

Prohibition of heavy vehicles, such as trucks or buses, or time restrictions on such vehicles, would require these vehicles to use adjacent local streets. This is not a feasible or reasonable noise abatement measure because it would be contrary to one of the major goals of the proposed project, i.e. to reduce heavy vehicle traffic on local and residential streets.

Reduction of travel speeds on Route 9A would not reduce project-related noise levels substantially. This is because lowering travel speeds substantially reduces noise levels on roadways that have relatively high speeds and low heavy vehicle percentages. On such roadways, the dominant noise source is tire-pavement noise, which is related to travel speed. In contrast, Route 9A has relatively low travel speeds and high heavy vehicle percentages. As a result, the dominant source of noise on Route 9A is not tire pavement noise, but truck and bus engine noise, as well as exhaust and cooling fan noise from these vehicles. These sources of noise are not sensitive to travel speed and would not be substantially reduced by lowering travel speeds.

CHANGES TO ROADWAY ALIGNMENT AND NOISE BUFFER ZONES

Large changes in the horizontal alignment of roadways can provide noise abatement by increasing distances to receptors, thus providing a noise buffer zone between the roadway and the affected receptors. However, distances must be increased by a factor of three to obtain five decibels of abatement. Such large shifts in the horizontal alignment of Route 9A are not possible within its constrained corridor. Lesser shifts would not produce substantial noise abatement.

NOISE INSULATION

FHWA regulations and NYSDOT policy allow the use of funds to improve the noise insulation of public schools. Within the noise study area, this would apply to Stuyvesant High School, P.S. 234 and P.S. 89. However, since these schools have been built to insulate against traffic noise, additional insulation would not be required.

FHWA regulations also allow use of federal funds for the noise insulation of public use or nonprofit institutional buildings. However, NYSDOT does not have the legal authority to provide noise insulation for such buildings. Neither FHWA nor NYSDOT allow the use of funds to insulate private residences, apartment buildings, condominiums, or hotels from noise.

NOISE BARRIERS

Noise barriers could provide approximately 8 to 10 decibels of noise abatement at certain receptor sites located close to Route 9A. To be acoustically effective, these barriers would have to be continuous, of sufficient length, and at least 8 to 10 feet tall. However, because such


10-20

barriers would be incompatible with two major objectives of the project—(1) to minimize physical barriers between the city and the river and (2) and to preserve to the fullest extent possible visual corridors to the waterfront—they are not considered a feasible and reasonable noise abatement measure.

Documents

Chapter 10: Noise A. INTRODUCTION