Table 3.10-6: SoundPlan Model Existing Roadway Parameters

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For each phase of construction, the equipment shown above in Table 3.10-4 and Table 3.10-5 was placed on the project site starting at the nearest locations to the sensitive receptors that they are likely to operate and each successive piece was placed 50 feet farther away.

SoundPlan Noise Modeling Software

Since noise in the project vicinity is created by multiple roadways, the SoundPlan Version 7.2 noise modeling software was used. SoundPlan’s road noise, parking lot noise, and stationary noise source algorithms are based on the FHWA Traffic Noise Model (FHWA TNM Model). The SoundPlan Model requires the input of roadways and the locations of the noise measurement receivers. Stationary noise sources with associated frequency spectrums, sound barriers, terrain contour lines, building placement, and specific ground coverage zones may be incorporated as well. The site plan and aerial photos were used to determine the placement of the roadways, parking lots, and stationary sources as well as to establish the terrain in the project vicinity. The default temperature of 20 degrees Celsius (68°F) and default humidity of 50 percent, which can vary the propagation of noise, were used in the analysis and represent reasonable assumptions, since they are near the averages experienced in the project vicinity.

Existing Roadway Assumptions

The model analyzed the noise impacts from the nearby roadways onto the project vicinity, which consists of the area analyzed in the Traffic Impact Analysis. All roadways were analyzed for a single-lane-equivalent noise source combining both directions of travel. In order to convert the peak-hour traffic volumes provided in the Traffic Impact Analysis into average daily traffic (ADT) volumes, the AM and PM peak-hour volumes were added together and multiplied by 5. The roadway parameters used for the SoundPlan modeling are presented in Table 3.10-6. The roadway classifications are based on the City of Morgan Hill General Plan Circulation Element. The roadway speed is based on the posted speed limits or the speed standards provided in the General Plan.

Table 3.10-6: SoundPlan Model Existing Roadway Parameters

Roadway Segment General Plan Classification

Vehicle Speed (miles per

hour)

Existing Average Daily

Traffic

Condit Road North of Tennant Avenue 2-Lane Collector 40 1,970

Murphy Avenue North of Barrett Avenue 2-Lane Arterial 40 1,740

Murphy Avenue South of Barrett Avenue 2-Lane Arterial 40 1,800

Murphy Avenue North of Tennant Avenue 2-Lane Arterial 40 1,660

Murphy Avenue South of Tennant Avenue 2-Lane Arterial 40 2,310

Barrett Avenue West of Murphy Avenue Local 25 10

Barrett Avenue East of Murphy Avenue Local 30 350

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Michael Brandman Associates 3.10-25 H:\Client (PN-JN)\2086\20860001\4 - Draft EIR\20860001 Sec03-10 Noise.doc

Table 3.10-6 (cont.): SoundPlan Model Existing Roadway Parameters


Vehicle Speed (miles per

hour)

Existing Average Daily

Traffic

Barrett Avenue East of High School Driveway

Local 30 350

Tennant Avenue West of Condit Road 6-Lane Arterial 45 7,410

Tennant Avenue West of Murphy Avenue 4-Lane Arterial 45 5,480

Tennant Avenue East of Murphy Avenue 4-Lane Arterial1 45 3,130

Tennant Avenue East of High School Driveway

4-Lane Arterial 45 3,130

US 101 South of Cochrane Road Freeway 65 134,300

Notes: 1 Tennant Avenue turns into a 2-lane collector east of Hill Road, however in order to provide a worst-case analysis, it

was analyzed as the louder 4-Lane Arterial for the entire length. Source: Fehr & Peers, 2013; Michael Brandman Associates, 2013.

Table 3.10-7 presents the hourly traffic flow distributions (vehicle mixes) used in this analysis. These distributions were obtained from Caltrans, from vehicle counts provided in the Traffic Impact Analysis (Fehr & Peers, 2013) and from field observations of similar local and arterial roads. The vehicle mix provides the hourly distribution percentages of automobiles, medium trucks, and heavy trucks for input into the FHWA and SoundPlan Models.

Table 3.10-7: Nearby Roadway Vehicle Mixes

Percent of Hourly Distribution

Roadway Classification Vehicle Type

Day (7 a.m. to

7 p.m.)

Evening (7 p.m. to 10 p.m.)

Night (10 p.m. to

7 a.m.) Overall

Automobiles 73.6 13.6 10.2 97.4

Medium Trucks 0.9 0.9 0.0 1.8

Local and Collectors

Heavy Trucks 0.4 0.0 0.4 0.7

Automobiles 69.5 12.9 9.6 92.0


Arterials

Heavy Trucks 2.4 0.1 2.5 5.0

Automobiles 62.8 12.9 15.1 90.8


US 101

Heavy Trucks 3.3 0.3 2.4 6.1

Source: California Department of Transportation, 2012; Michael Brandman Associates, 2013.



In order to determine the height above the road grade from where the noise is being emitted, each type of vehicle has been analyzed independently with autos at road grade, medium trucks at 2.3 feet above road grade, and heavy trucks at 8 feet above road grade. These elevations were determined through a noise-weighted average of the elevation of the exhaust pipe, tires, and mechanical parts in the engine, which are the primary noise emitters from a vehicle.

Modeling Calibration

Receivers were placed at the location of the noise measurement sites in order to assist in the calibration of the noise sources inputted into the model as well as to verify the accuracy of the SoundPlan Model. Table 3.10-8 provides a summary of the calculated results, and a comparison with the measured results is shown above in Table 3.10-1.

Table 3.10-8: SoundPlan Model Calibration to Existing 24-Hour Noise Levels

Site No. Site Description

Calculated Noise Level1

(dBA Ldn)

Measured Noise Level2

(dBA Ldn) Difference

A Located on a tree approximately 35 feet north of Barrett Avenue Centerline in front of the home at 1505 Barrett Avenue.

57.5 59.2 -1.7

B Located on a telephone pole approximately 30 feet south of Tennant Avenue Centerline in front of the home and office at 1630 Tennant Avenue.

70.9 73.0 -2.1

C Located on a tree next to Hampton Inn approximately 140 feet north of Tennant Avenue Centerline and 120 feet west of Condit Road Centerline.

65.4 64.0 1.4

D Located on a tree approximately 35 feet east of Murphy Avenue Centerline in front of the home at 16400 Murphy Avenue.

64.6 66.8 -2.2

Notes:

1 Noise level calculated from SoundPlan Version 7.2. 2 Noise measurements taken on January 24 and 25, 2013. Source: Michael Brandman Associates, 2013.

Table 3.10-8 shows the model calibration accuracy to the long-term noise measurements and found that the model is within 2.2 dBA of the measured noise levels, which is within the range of allowed tolerances as described in Section 5.4.1, Routine Model Calibration, of the Caltrans Technical Noise Supplement for the multiple range of noise sources impacting the project site. Therefore, based on the field noise measurements, the SoundPlan Model provides an accurate representation of the project area noise levels.

FHWA-RD-77-108 Traffic Noise Prediction Model

To predict existing and future noise levels due to traffic traveling 25 miles per hour or above, a computer program that replicates the FHWA Traffic Noise Prediction Model FHWA-RD-77-108 was utilized. The FHWA-RD-77-108 Model arrives at a predicted noise level through a series of



adjustments to the Reference Energy Mean Emission Level. Adjustments are then made to the reference energy mean emission level to account for the roadway active width (i.e., the distance between the center of the outermost travel lanes on each side of the roadway); the total average daily traffic (ADT) and the percentage of ADT that flows during the day, evening, and night; the travel speed; the vehicle mix on the roadway; a percentage of the volume of automobiles, medium trucks, and heavy trucks; the roadway grade; the angle of view of the observer exposed to the roadway; and the site conditions (“hard” or “soft”) as they relate to the absorption of the ground, pavement, or landscaping.

Traffic Noise Prediction Model Inputs

The roadway parameters used for this study are presented in Table 3.10-9 for the SEQ Area analysis and in Table 3.10-10 for the proposed High School analysis. The roadway classifications are based on the City of Morgan Hill General Plan Circulation Element. The roadway speeds are based on the posted speed limits. The distance to the nearby receptors was determined by measuring the distance from the roadway centerline to the nearest occupied structure. Only the roadway segments that had occupied structures in the nearby vicinity of the roadway were analyzed. Since the study area is located in a rural environment and landscaping or agriculture exists along the sides of all analyzed roadways, soft surface conditions were used to develop noise contours and analyze noise impacts to the project study area.

Table 3.10-9: FHWA Model Roadway Parameters for SEQ Area Analysis


Vehicle Speed (miles

per hour)

Distance to Receptor

(feet)

Dunne Avenue West of US 101 Southbound Ramps1

4-Lane Arterial 45 90

Dunne Avenue West of Condit Road1 4-Lane Arterial 45 110

Dunne Avenue West of Murphy Avenue2 4-Lane Arterial 45 80

Dunne Avenue East of Murphy Avenue2 4-Lane Arterial 45 80

Tennant Avenue West of US 101 Southbound Ramps3


Tennant Avenue West of Condit Road4 6-Lane Arterial 45 150

Tennant Avenue East of Murphy Avenue2 4-Lane Arterial 45 70

Tennant Avenue East of Hill Road2 2-Lane Collector 45 40

Murphy Avenue South of Dunne Avenue2 2-Lane Arterial 40 65

Murphy Avenue North of Barrett Avenue2 2-Lane Arterial 40 75

Murphy Avenue North of Tennant Avenue2 2-Lane Arterial 40 270

Murphy Avenue South of Tennant Avenue2 2-Lane Arterial 40 100



Table 3.10-9 (cont.): FHWA Model Roadway Parameters for SEQ Area Analysis


Vehicle Speed (miles

per hour)


(feet)

Murphy Avenue South of Fisher Avenue2 4-Lane Arterial 45 60

Murphy Avenue South of Maple Avenue2 2-Lane Arterial 40 65

Barrett Avenue East of Murphy Avenue2 Local 30 60

Hill Road North of Tennant Avenue2 2-Lane Arterial 40 70

Hill Road South of Tennant Avenue2 2-Lane Collector 40 40

Maple Avenue East of Murphy Avenue2 Local 30 60

Foothill Avenue South of Tennant Avenue2 2-Lane Collector 35 55

Foothill Avenue South of Maple Avenue2 2-Lane Collector 35 90

Notes: 1 Nearest structure is commercial. 2 Nearest structure is residential. 3 Nearest structure is a church. 4 Nearest structure is transient lodging. Source: City of Morgan Hill, 2010; Michael Brandman Associates, 2013.

Table 3.10-10: FHWA Model Roadway Parameters for the Proposed High School Analysis


Vehicle Speed

(miles per hour)


(feet)

Butterfield Boulevard North of Tennant Avenue1 4-Lane Arterial 45 120

Juan Hernandez Drive North of Tennant Avenue1 2-Lane Collector 35 50

Condit Road South of Dunne Avenue1 2-Lane Collector 40 65

Condit Road North of Tennant Avenue2 2-Lane Collector 40 85

Murphy Avenue South of Dunne Avenue3 2-Lane Arterial 40 65

Murphy Avenue North of Barrett Avenue1 2-Lane Arterial 40 75

Murphy Avenue South of Barrett Avenue1 2-Lane Arterial 40 270

Murphy Avenue South of Tennant Avenue1 2-Lane Arterial 40 100

Dunne Avenue West of US 101 Southbound Ramps2


Dunne Avenue West of Condit Road2 4-Lane Arterial 45 110

Dunne Avenue West of Murphy Avenue1 4-Lane Arterial 45 80

Dunne Avenue East of Murphy Avenue1 4-Lane Arterial 45 80

Barrett Avenue East of Murphy Avenue1 Local 30 60



Table 3.10-10 (cont.): FHWA Model Roadway Parameters for the Proposed High School Analysis


Vehicle Speed

(miles per hour)


(feet)

Tennant Avenue West of Butterfield Boulevard2 4-Lane Arterial 45 80

Tennant Avenue West of US 101 Southbound Ramps4


Tennant Avenue West of Condit Road3 6-Lane Arterial 45 150

Tennant Avenue East of Murphy Avenue1 4-Lane Arterial5 45 70

Notes: 1 Nearest structure is residential. 2 Nearest structure is commercial. 3 Nearest structure is transient lodging. 4 Nearest structure is a church. 5 Tennant Avenue turns into a 2-lane collector east of Hill Road, however in order to provide a worst-case analysis, it

was analyzed as the louder 4-Lane Arterial for the entire length. Source: City of Morgan Hill, 2010; Michael Brandman Associates, 2013.

In order to determine the offsite project-generated traffic noise impacts, the average daily traffic volumes on the study area roadways were obtained from the Traffic Impact Analysis. The peak-hour volumes were provided for the existing year without and with the development projects within the SEQ Area and with proposed High School, and year 2030 without and with SEQ Area project and proposed High School scenarios. The ADT volumes were calculated by multiplying the AM and PM peak-hour volumes by 5. The calculated ADT volumes are shown in Table 3.10-11 for the SEQ Area conditions and Table 3.10-12 for the proposed High School conditions.

Table 3.10-11: Average Daily Traffic Volumes for SEQ Area Analysis

SEQ Area Average Daily Traffic

Existing Year 2030

Roadway Segment No

Project With

Project No

Project With

Project

Dunne Avenue West of US 101 Southbound Ramps

20,740 21,770 23,150 23,950

Dunne Avenue West of Condit Road 16,870 19,700 20,700 23,400

Dunne Avenue West of Murphy Avenue 13,000 15,520 16,050 18,400

Dunne Avenue East of Murphy Avenue 13,190 13,830 17,250 17,850

Tennant Avenue West of US 101 Southbound Ramps

20,330 25,880 36,300 39,700

Tennant Avenue West of Condit Road 7,410 28,860 10,750 31,850

Tennant Avenue East of Murphy Avenue 3,130 8,890 5,300 10,700



Table 3.10-11 (cont.): Average Daily Traffic Volumes for SEQ Area Analysis

SEQ Area Average Daily Traffic

Existing Year 2030

Roadway Segment No

Project With

Project No

Project With

Project

Tennant Avenue East of Hill Road 1,220 2,410 2,150 2,850

Murphy Avenue South of Dunne Avenue 2,090 5,150 5,650 6,950

Murphy Avenue North of Barrett Avenue 1,740 4,560 4,350 5,800

Murphy Avenue North of Tennant Avenue 1,800 4,570 4,400 5,950

Murphy Avenue South of Tennant Avenue 2,310 11,610 5,250 12,100

Murphy Avenue South of Fisher Avenue 2,350 2,490 5,900 5,900

Murphy Avenue South of Maple Avenue 1,360 1,360 4,700 4,700

Barrett Avenue East of Murphy Avenue 350 850 650 1,150

Hill Road North of Tennant Avenue 3,840 4,500 5,450 6,050

Hill Road South of Tennant Avenue 1,300 1,820 1,500 2,050

Maple Avenue East of Murphy Avenue 1,090 1,230 5,350 5,350

Foothill Avenue South of Tennant Avenue 1,050 1,470 1,650 1,850

Foothill Avenue South of Maple Avenue 890 890 1,450 1,450

Source: Fehr & Peers, 2013; Michael Brandman Associates, 2013

Table 3.10-12: Average Daily Traffic Volumes for Proposed High School Analysis

Proposed High School Average Daily Traffic

Existing Year 2030

Roadway Segment No

Project With

Project No

Project With

Project

Butterfield Boulevard North of Tennant Avenue 6,240 6,680 15,930 16,370

Juan Hernandez Drive North of Tennant Avenue 1,840 1,960 8,010 8,130

Condit Road South of Dunne Avenue 2,340 2,340 3,450 3,450

Condit Road North of Tennant Avenue 1,970 1,970 3,100 3,100

Murphy Avenue South of Dunne Avenue 2,090 4,120 5,650 5,990


Murphy Avenue South of Barrett Avenue 1,800 3,760 3,150 5,160



Table 3.10-12 (cont.): Average Daily Traffic Volumes for Proposed High School Analysis

Proposed High School Average Daily Traffic

Existing Year 2030

Roadway Segment No

Project With

Project No

Project With

Project



20,740 21,300 23,150 23,680

Dunne Avenue West of Condit Road 16,870 18,670 20,700 22,460

Dunne Avenue West of Murphy Avenue 13,000 14,790 16,050 17,810

Dunne Avenue East of Murphy Avenue 13,190 13,430 17,250 17,460


Tennant Avenue West of Butterfield Boulevard 21,600 21,600 22,410 23,020


20,330 21,490 36,300 37,450



Source: Fehr & Peers, 2013; Michael Brandman Associates, 2013

The vehicle mixes used in the FHWA-RD-77-108 Model have previously been provided in Table 3.10-7.

Source Assumptions

To assess the roadway noise generation in a uniform manner, all vehicles were analyzed at the single-lane-equivalent acoustic center of the roadway being analyzed, which means that all lanes were analyzed as one lane located at the centerline of the roadway, instead of analyzing each lane in the roadway as a separate noise source. The width of each single-lane equivalent was based on the right-of-way and near-far lane lengths (i.e., the distance between the middle lines of each outside lane) as determined by the General Plan Roadway Classification. In order to determine the height above the road grade from where the noise is being emitted, each type of vehicle has been analyzed independently with autos at road grade, medium trucks at 2.3 feet above road grade, and heavy trucks at 8 feet above road grade. These elevations were determined through a noise-weighted average of the elevation of the exhaust pipe, tires, and mechanical parts in the engine, which are the primary noise emitters from a vehicle.

Stationary and Other Noise Sources Impacts

In order to determine the proposed project impacts onto the nearby sensitive receptors, the proposed High School’s onsite stationary and other noise sources without public roadway noise was analyzed



using the SoundPlan model. The analysis has been based on the SoundPlan modeling methodology presented above for the existing scenario. The following describes the anticipated stationary and other noise sources that would occur during the ongoing operations of the proposed High School. It is important to note that the Traffic Impact Analysis assumed full buildout of the High School in one phase, representing a worst-case scenario. Therefore, the corresponding noise modeling also represents a worst-case scenario analysis. As described in the Project Description section of this Draft EIR, the High School will be developed in multiple phases spanning a number of years.

Proposed High School Onsite Driveway Assumptions

The onsite driveways located on the project site have been analyzed as stationary and other noise sources, since the driveways are located on private property and thus are not exempt from local noise regulations. The Traffic Impact Analysis provided the High School peak-hour traffic volumes for each of the three proposed driveways and found that the proposed High School would generate 3,968 daily vehicular trips. Through use of the ratios of the peak-hour driveway traffic volumes to the total daily trips it was determined that the driveway off Murphy Avenue would have 2,380 trips per day, the driveway off Barrett Avenue would have 200 trips per day, and the driveway off Tennant Avenue would have 1,390 trips per day. All driveways were analyzed for a speed of 15 miles per hour.

The hourly traffic flow distributions (vehicle mixes) used for the onsite driveways have been based on the collector vehicle mix that was provided previously in Table 3.10-7. In order to determine the height above the road grade from where the noise is being emitted, each type of vehicle has been analyzed independently with autos at road grade, medium trucks at 2.3 feet above road grade, and heavy trucks at 8 feet above road grade. These elevations were determined through a noise-weighted average of the elevation of the exhaust pipe, tires, and mechanical parts in the engine, which are the primary noise emitters from a vehicle.

Proposed High School Parking Lot Assumptions

The SoundPlan model analyzed the noise impacts from the proposed High School parking lots. The parking lot emission source is based on the different tonal contents typically created from parking lots and is primarily from engine and tire noise, slamming of doors, pedestrians, and street sweepers. The movement per parking space per hour was calculated based on the High School driveway project trip from the Traffic Impact Analysis and detailed above for the onsite driveway assumptions. The parking space movements were based on the assumption that 90 percent of the trips would occur between 7 a.m. and 10 p.m. A summary of the parking lot movements is provided in Table 3.10-13.



Table 3.10-13: With Project Parking Lot Movements

Movement per Space per Hour Parking Lot

Approximate Number of Parking Spaces

Trips per Lot per Day 7 a.m. – 7 p.m. 7 p.m. – 7 a.m.

North Lot 80 200 0.19 0.02

West Lot 350 2,380 0.51 0.06

South Lot 305 1,390 0.34 0.04

Source: Fehr & Peers, 2013; Michael Brandman Associates, 2013.

In order to determine the maximum noise created by parking lots, a 24-hour noise measurement was taken at the main parking lot at an existing Catholic high school of similar size in Northern California, which measured a maximum noise level of 76.9 dBA Lmax. The maximum noise level occurred at 9:20 p.m. and was most likely created from facility maintenance or street sweeper operations.

Proposed High School Rooftop Mechanical Equipment Assumptions

The SoundPlan model also analyzed the noise impacts from the proposed rooftop mechanical equipment on the six proposed structures for the High School. The rooftop mechanical noise levels were calibrated to noise measurements of a rooftop unit on a similar size building. The noise measurement was taken 10 feet from an operational rooftop unit, which measured a noise level of 59.5 dBA Leq and 60.3 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. The reference noise measurement was also cross-checked for pure tones, which found no pure tones were created during the noise measurement of the rooftop mechanical equipment. Each rooftop mechanical equipment unit was modeled for running 50 percent of each hour between the hours of 7 a.m. and 5 p.m. Each forced air unit is anticipated to meet the energy reduction requirements provided in Title 24, which require the use of thermostats that are programmed to turn off when the buildings are not in use. Each building was modeled with rooftop mechanical equipment covering 20 percent of the roof area. Each rooftop unit was modeled as an area source located 3 feet above the roof level and calibrated to a noise level of 59.5 dBA Leq at 10 feet. The maximum noise analysis from the rooftop mechanical equipment has been based on the reference noise measurement, which captured a maximum noise of 60.3 dBA Lmax.

Proposed High School Football and Track Field

The SoundPlan model also analyzed the noise impacts from the proposed High School football and track field. The football field noise levels were calibrated to a noise measurement of a high school football game at an existing Catholic high school similar in size to the proposed High School. The noise measurement was taken 70 feet from the football field during a varsity football game and measured noise levels of 63.3 dBA Leq and 77.0 dBA Lmax. The octave center frequency sound



pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. The football field was modeled as an area source 5 feet above ground level, calibrated to a noise level of 63.3 dBA Leq at 70 feet, and operational between the hours of 5 p.m. and 9 p.m., which is when high school games typically occur.

Proposed High School Multipurpose Field

The SoundPlan model also analyzed the noise impacts from the proposed High School’s multipurpose field located in the northwest corner of the project site. The multipurpose field would be used as a practice field for football, soccer, and baseball. The multipurpose field noise levels were calibrated to a noise measurement of a high school football practice at an existing Catholic high school, which is a private high school similar to the proposed High School. The noise measurement was taken at the edge of the football practice field and as near as 50 feet from activities on the field and measured noise levels of 58.7 dBA Leq and 77.4 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. The multipurpose field was modeled as an area source 5 feet above ground level, calibrated to a noise level of 58.7 dBA Leq at 50 feet, and operational between the hours of 2 p.m. and 5 p.m., which is when high school sports practice typically occurs.

Proposed High School Baseball Fields

The SoundPlan model also analyzed the noise impacts from the two proposed High School baseball fields located in the northeast corner of the project site. The two baseball fields’ noise levels were calibrated to a noise measurement of a youth softball game at an existing public park. The noise measurement was taken approximately 20 feet from third base and measured noise levels of 57.8 dBA Leq and 67.6 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. Both baseball fields were modeled as an area source 5 feet above ground level, calibrated to a noise level of 57.8 dBA Leq at 20 feet, and operational between the hours of 2 p.m. and 5 p.m., which is when High School baseball practice and games typically occur.

Proposed High School Tennis Courts

The SoundPlan model also analyzed the noise impacts from the six proposed tennis courts located in the northern portion of the project site. The six tennis courts noise levels were calibrated to a noise measurement of four-some playing in an organized tennis match at an existing tennis complex with more than six courts. The noise measurement was taken approximately 5 feet from the net and measured noise levels of 50.7 dBA Leq and 72.9 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. All six tennis courts were modeled as an area source 5 feet above ground level, calibrated to a noise level of 50.7 dBA Leq at 5



feet, and operational between the hours of 2 p.m. and 5 p.m., which is when High School tennis practice and games typically occur.

Proposed High School Basketball Courts

The SoundPlan model also analyzed the noise impacts from the five proposed basketball courts located between the tennis courts, baseball field, and football field. The five basketball courts noise levels were calibrated to a noise measurement of a youth basketball practice on six adjacent basketball courts at an existing school. The youth basketball practice was chosen since children typically produce higher noise levels than other age levels, and therefore, provides a more conservative analysis. The noise measurement was taken approximately 50 feet from the middle basketball hoop and measured noise levels of 62.2 dBA Leq and 87.8 dBA Lmax. The octave center frequency sound pressure levels were not available from the reference noise measurement, so the multipurpose field octave center frequency sound pressure levels were utilized in the SoundPlan Model. The group of three basketball courts were modeled as an area source, and the group of two basketball courts were modeled as a separate area source 5 feet above ground level, calibrated to a noise level of 62.2 dBA Leq at 50 feet, and operational between the hours of 8 a.m. and 2 p.m., which is when high school physical education courses typically occur, since the High School basketball team would utilize the indoor basketball court for practice and games.

Proposed High School Pool

The SoundPlan model also analyzed the noise impacts from the proposed High School’s pool located on the north side of the proposed gymnasium. The pool noise level was calibrated to a noise measurement of an existing high school pool of similar size to that of the proposed project in the summer when the pool was open to the general public and a variety of activities were occurring with approximately 50 people using the pool facility. The noise measurement was taken approximately 15 feet from the pool area and measured noise levels of 66.6 dBA Leq and 77.3 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to enable the Model to calculate the appropriate sound attenuation rates. The pool area was modeled as an area source at ground level, calibrated to a noise level of 66.6 dBA Leq at 15 feet, and operational between the hours of 6 a.m. and 8 a.m. and 2 p.m. and 5 p.m., which is when high school pools are typically used.

Proposed High School Plaza

The SoundPlan model also analyzed the noise impacts from the proposed High School plaza located at the center of campus, which may have pep rallies and bands during lunchtime. The plaza noise level was calibrated to a noise measurement of the plaza at an existing Catholic high school during lunchtime, when a band was playing in the plaza and a couple of hundred students were watching the band and eating lunch. The noise measurement was taken approximately 70 feet from the plaza area and measured noise levels of 55.6 dBA Leq and 70.1 dBA Lmax. The octave center frequency sound pressure levels from the reference noise measurement were inputted into the SoundPlan Model, to



enable the Model to calculate the appropriate sound attenuation rates. The plaza area was modeled as an area source 5 feet above ground level, calibrated to a noise level of 55.6 dBA Leq at 70 feet, and operational between the hours of 12 p.m. and 1 p.m.

Combined Stationary and Other Noise Sources with Public Roadway Noise Impacts

In order to determine the combined stationary and other noise sources with public roadway noise impacts created by the proposed High School onto the nearby sensitive receptors, the SoundPlan Model modeling software was utilized. The following describes the input parameters of the SoundPlan model that were modified from the existing and stationary and other noise sources scenarios for the combined stationary and other noise sources with public roadway noise impacts scenario.

Roadway Assumptions

The roadways that were analyzed in the existing scenario have been analyzed in the SoundPlan Model for the existing year without and with proposed High School project scenarios and year 2030 without and with proposed High School project scenarios. Other than the onsite roads, which have changed, the rest of the roadways analyzed in the SoundPlan model are the same as what was analyzed in the existing conditions shown above in Table 3.10-6. The traffic volumes used in the analysis are shown in Table 3.10-14.

Table 3.10-14: SoundPlan Model Roadway Parameters for Proposed High School Analysis

Average Daily Traffic Volumes

Roadway Segment Existing No

Project

Existing With High

School Year 2030 No Project

Year 2030 With High

School

Condit Road North of Tennant Avenue 1,970 1,970 3,100 3,100


Murphy Avenue South of Barrett Avenue 1,800 3,760 3,150 5,160

Murphy Avenue North of Tennant Avenue 1,660 4,890 3,150 6,380


Barrett Avenue West of Murphy Avenue 10 10 100 100


Barrett Avenue East of High School Driveway

350 350 650 650


Tennant Avenue West of Murphy Avenue 5,480 11,300 8,350 14,170




Table 3.10-14 (cont.): SoundPlan Model Roadway Parameters for Proposed High School Analysis

Average Daily Traffic Volumes

Roadway Segment Existing No

Project

Existing With High

School Year 2030 No Project

Year 2030 With High

School

Tennant Avenue East of High School Driveway

3,130 3,130 5,300 5,300

US 101 South of Cochrane Road 134,300 134,300 165,5001 165,5001

Note: 1 Based on a 1 percent per year growth rate. Source: California Department of Transportation, 2012; Fehr & Peers, 2013; Michael Brandman Associates, 2013

The hourly traffic flow distributions (vehicle mixes) used in this analysis have been provided above in Table 3.10-7, and the roadways were assigned the same vehicle mixes used for the existing conditions.

Construction-Related Vibration Level Prediction

Construction and operational activities can result in varying degrees of ground vibration, depending on the equipment used on the site. Operation of construction equipment causes ground vibrations that spread through the ground and diminish in strength with distance. Buildings in the vicinity of the construction site respond to these vibrations with varying results ranging from no perceptible effects at the low levels to slight damage at the highest levels. Table 3.10-15 gives approximate vibration levels for particular construction activities. The data in the table provide a reasonable estimate for a wide range of soil conditions.

Table 3.10-15: Vibration Source Levels for Construction Equipment

Equipment Peak Particle Velocity

(inches/second) Approximate Vibration Level

(Lv) at 25 feet

Pile driver (impact) 1.518 (upper range) 0.644 (typical)

112 104

Pile driver (sonic) 0.734 (upper range) 0.170 (typical)

105 93

Clam shovel drop (slurry wall) 0.202 94

Hydromill (slurry wall) 0.008 (in soil) 0.017 (in rock)

66 75

Vibratory Roller 0.210 94

Hoe Ram 0.089 87

Large bulldozer 0.089 87



Table 3.10-15 (cont.): Vibration Source Levels for Construction Equipment

Equipment Peak Particle Velocity

(inches/second) Approximate Vibration Level

(Lv) at 25 feet

Caisson drill 0.089 87

Loaded trucks 0.076 86

Jackhammer 0.035 79

Small bulldozer 0.003 58

Source: Federal Transit Administration, 2006.

The construction-related and operational vibration impacts have been calculated through the vibration levels shown above in Table 3.10-15 and through typical vibration propagation rates. The construction equipment assumptions were based on the equipment lists shown above in Table 3.10-4 for the development projects within the SEQ Area and in Table 3.10-5 for the proposed High School.

3.10.5 - Thresholds of Significance According to Appendix G, Environmental Checklist, of the CEQA Guidelines, noise impacts resulting from the implementation of the proposed project would be considered significant if the project would cause:

a.) 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?

b.) Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels?

c.) A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project?

d.) A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project?

e.) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? (Refer to Section 7, Effects Found Not To Be Significant.)

f.) For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels? (Refer to Section 7, Effects Found Not To Be Significant.)



3.10.6 - Project Impacts and Mitigation Measures This section discusses potential impacts associated with the development of the project and provides mitigation measures where appropriate.

Generation of Noise Levels in Excess of Standards

Impact NOI-1: Construction and operational activities associated with the proposed project would expose persons to or generate noise levels in excess of standards established in the General Plan or Noise Ordinance or applicable standards of other agencies.

Impact Analysis

The following section calculates the potential noise emissions associated with the construction and operations of the proposed development projects within the SEQ Area and proposed High School project, and compares the noise levels with city standards, since future development analyzed within this Draft EIR would occur within the City of Morgan Hill.

Noise Standards The City has developed the following noise standards for construction noise, stationary and other noise sources, and roadway noise and combined road and stationary noise, which are detailed below.

Construction Noise The City of Morgan Hill Municipal Code Section 8.28.040 generally prohibits construction activities other than between the hours of 7:00 a.m. and 8:00 p.m., Monday through Friday, and between the hours of 9:00 a.m. and 6:00 p.m. on Saturday, except for Sundays or federal holidays.

Stationary and Other Noise Sources The City of Morgan Hill Policies 7f and 7g state that stationary noise sources and other noise sources such as ballfields would create a significant noise impact if they would substantially exceed ambient noise levels. The City of Morgan Hill Municipal Code Section 18.48.075 specifies maximum exterior noise levels at the lot line of the adjacent use of 75 dBA for industrial uses, 65 dBA for office, retail or sensitive industries and 60 dBA for residential, park, or institutional uses.

Since Policies 7f and 7g do not quantify what is a substantial noise increase, the substantial increase standard of a 5 dB increase where the “with project” noise level is less than 60 dBA Ldn, has been utilized in analyzing stationary noise impacts in addition to the noise standards provided in Municipal Code Section 18.48.075.

Roadway Noise and Combined Road and Stationary Noise The City of Morgan Hill General Plan Policy 7e states that traffic noise increases from a proposed project shall be considered significant if: a) the noise level increase is 5 dBA Ldn or greater, with a future noise level of less than 60 dBA Ldn, or b) the noise level increase is 3 dBA Ldn or greater, with a future noise level of 60 dBA Ldn or greater.



SEQ Area (Program Level) SEQ Area Project Construction-Related Noise Noise impacts from construction activities associated with development of the Craiker Sports Retail and Restaurant Uses, Puliafico SRL Uses, Jacoby SRL Uses, Chiala Planned Development, and city-initiated land use changes, which are part of the SEQ Area program level analysis, were evaluated. Construction noise impacts would be a function of the noise generated by construction equipment, equipment location, sensitivity of nearby land uses, and the timing and duration of the construction activities.

Section 8.28.040 of the Municipal Code limits construction activities to between the hours of 7:00 a.m. and 8:00 p.m., Monday through Friday, and between the hours of 9:00 a.m. and 6:00 p.m. on Saturday, except for Sundays or federal holidays. Through adherence to the limitation of allowable construction times provided in Section 8.28.040 of the Municipal Code, the construction-related noise levels in the SEQ Area would not exceed any standards. Impacts would be less than significant.

SEQ Area Project Stationary and Other Noise Sources The SEQ Area includes the Craiker Sports Retail and Restaurant Uses, Puliafico SRL Uses, Jacoby SRL Uses, Chiala Planned Development, and city-initiated land use changes that have not yet been designed, and therefore it is unknown what, if any stationary and other noise sources would exist at each of the development sites as well as the distances of these noise sources to nearby sensitive receptors, which is required to provide a quantitative analysis of noise impacts. Although it is too speculative to quantify the SEQ Area stationary and other noise source impacts, there is a potential that the development projects within the SEQ Area could create stationary noise levels that would exceed the City standards. This would be considered a significant impact.

Mitigation Measure NOI-1a is provided that would require future development activities within the SEQ Area to submit a noise impact analysis that analyzes and quantifies each project’s potential stationary and other noise sources noise impacts to nearby sensitive receptors at the time of entitlement for each project. Several feasible mitigation measures and project design features including source placement, limitation on operational hours and sound walls are available to reduce any potential stationary noise impacts to within the City standard. Impacts would be reduced to less than significant with implementation of Mitigation Measure NOI-1a.

SEQ Area Project Roadway Noise The proposed project would generate additional vehicular trips on roadways in the project vicinity. Noise from motor vehicles is generated by engine vibrations, the interaction between tires and the road, and the exhaust system.

In order to quantify the traffic noise impacts along the analyzed roadways with nearby noise-sensitive uses, the roadway noise contours were calculated. Noise contours represent the distance to noise levels of a constant value and are measured from the center of the roadway. For analysis comparison



purposes, the Ldn and CNEL noise levels are calculated at the distance to the nearest sensitive receptor, which was determined from aerial photos of the study area. In addition, the distance from the centerline to the 55-, 60-, 65-, and 70-dBA noise levels are calculated for both Ldn and CNEL standards and are shown in the noise calculation spreadsheets provided in Appendix G. The proposed project’s offsite traffic noise impacts have been analyzed for the existing and year 2030 conditions and are discussed below.

Existing Conditions The SEQ Area’s potential offsite traffic noise impacts have been calculated through a comparison between the existing without-project scenario and the existing with SEQ Area scenario. The results of this comparison are shown in Table 3.10-16.

Table 3.10-16: Existing SEQ Area Project Traffic Noise Contributions

dBA Ldn at Nearest Structure1

Roadway Segment No

ProjectWith

ProjectProject

Contribution

Potential Significant

Impact?

Dunne Avenue West of US 101 Southbound Ramps 64.9 65.1 0.2 No

Dunne Avenue West of Condit Road 62.6 63.2 0.6 No

Dunne Avenue West of Murphy Avenue 63.7 64.4 0.7 No

Dunne Avenue East of Murphy Avenue 63.7 63.9 0.2 No

Tennant Avenue West of US 101 Southbound Ramps 56.7 57.8 1.1 No

Tennant Avenue West of Condit Road 57.0 62.9 5.9 Yes

Tennant Avenue East of Murphy Avenue 58.4 63.0 4.6 Yes

Tennant Avenue East of Hill Road 54.5 57.5 3.0 No

Murphy Avenue South of Dunne Avenue 55.6 59.5 3.9 No

Murphy Avenue North of Barrett Avenue 53.8 58.0 4.2 No

Murphy Avenue North of Tennant Avenue 45.5 49.6 4.1 No

Murphy Avenue South of Tennant Avenue 53.1 60.1 7.0 Yes

Murphy Avenue South of Fisher Avenue 58.4 58.6 0.2 No

Murphy Avenue South of Maple Avenue 53.7 53.7 0.0 No

Barrett Avenue East of Murphy Avenue 44.3 48.2 3.9 No

Hill Road North of Tennant Avenue 57.7 58.4 0.7 No

Hill Road South of Tennant Avenue 54.8 56.3 1.5 No

Maple Avenue East of Murphy Avenue 49.3 49.8 0.5 No

Foothill Avenue South of Tennant Avenue 51.7 53.1 1.4 No



Table 3.10-16 (cont.): Existing SEQ Area Project Traffic Noise Contributions


Roadway Segment No

ProjectWith

ProjectProject

Contribution


Impact?

Foothill Avenue South of Maple Avenue 47.7 47.7 0.0 No

Note: 1 Distance to nearest structure shown in Table 3.10-9. Source: Michael Brandman Associates, 2013.

Table 3.10-16 above shows that for the existing conditions, noise level contributions from future development within the SEQ Area to the study area roadways would range from 0.0 to 7.0 dBA Ldn.

For the roadway segments that would experience less than 60 dBA Ldn for the with project conditions,

a significant impact would occur if the project would contribute 5 dB or more of noise. As shown in Table 3.10-16, the project contribution would be 4.2 dB or less to those roadway segments that would experience less than 60 dBA Ldn for the with project condition, which is within the 5-dB or more threshold. Impacts would be less than significant.

For the roadway segments that would experience 60 or more dBA Ldn for the with project conditions,

a significant impact would occur if the project would contribute 3 dB or more of noise. As shown in Table 3.10-16, the project contribution to those roadway segments that would experience more than 60 dBA Ldn for the with project condition would range between 0.2 and 7.0 dB and would exceed the 3-dB increase threshold at the roadway segments of Tennant Avenue west of Condit Road, Tennant Avenue east of Murphy Avenue, and Murphy Avenue south of Tennant Avenue. This would be considered a significant impact.

The noise levels shown above in Table 3.10-16 are based only on the noise created by each roadway segment and do not consider the entire noise environment, which is often impacted by multiple roadways and stationary sources. When all noise sources are considered, the project contribution to these roadway segments would be reduced; however, it is speculative to assume that consideration of other noise sources would reduce the project impacts to less than significant levels.

Mitigation Measure NOI-1b is provided that would require the City of Morgan Hill to consider reducing the speed limits, restricting trucks, and providing other traffic calming measures such as installation of center dividers and narrowing the lane widths, or installing sounds walls or landscaped berms along the following roadway segments: Tennant Avenue west of Condit Road; Tennant Avenue east of Murphy Avenue; and Murphy Avenue south of Tennant Avenue. According to Caltrans, a 5-mile-per-hour decrease in vehicle speeds would reduce the noise level between 1 and 2 dB, and restricting truck traffic has the potential to provide even greater noise levels reductions; however, it is dependent on how many trucks are currently using these roadway segments.



Implementation of Mitigation Measure NOI-1b has the potential to reduce the roadway noise impacts to less than significant; however, the measures detailed in Mitigation Measure NOI-1b may conflict with other City safety and circulation goals and policies and may not be feasible to implement. Therefore, this would result in a significant unavoidable impact for existing plus project conditions.

Year 2030 Conditions The SEQ Area potential offsite traffic noise impacts have been calculated through a comparison between the year 2030 without-project scenario and the year 2030 with SEQ Area scenario. The results of this comparison are shown in Table 3.10-17.

Table 3.10-17: Year 2030 SEQ Area Traffic Noise Contributions


Roadway Segment No

Project With

ProjectProject

Contribution


Impact?

Dunne Avenue West of US 101 Southbound Ramps 65.3 65.5 0.2

No




Tennant Avenue West of US 101 Southbound Ramps 59.3 59.6 0.3

No

Tennant Avenue West of Condit Road 58.7 63.4 4.7 Yes

Tennant Avenue East of Murphy Avenue 60.7 63.8 3.1 Yes

Tennant Avenue East of Hill Road 57.0 58.2 1.2 No



Murphy Avenue North of Tennant Avenue 49.4 50.7 1.3 No

Murphy Avenue South of Tennant Avenue 56.7 60.3 3.6 Yes

Murphy Avenue South of Fisher Avenue 62.4 62.4 0.0 No

Murphy Avenue South of Maple Avenue 59.1 59.1 0.0 No


Hill Road North of Tennant Avenue 59.2 59.7 0.5 No

Hill Road South of Tennant Avenue 55.4 56.8 1.4 No

Maple Avenue East of Murphy Avenue 56.2 56.2 0.0 No

Foothill Avenue South of Tennant Avenue 53.6 54.1 0.5 No

Foothill Avenue South of Maple Avenue 49.8 49.8 0.0 No



Table 3.10-17 (cont.): Year 2030 SEQ Area Traffic Noise Contributions


Roadway Segment No

Project With

ProjectProject

Contribution


Impact?

Note: 1 Distance to nearest structure shown in Table 3.10-12. Source: Michael Brandman Associates, 2013.

Table 3.10-17 above shows that for the year 2030 conditions, noise level contributions from the development projects within the SEQ Area to the study area roadways would range from 0.0 to 4.7 dBA Ldn.

For the roadway segments that would experience less than 60 dBA Ldn for the year 2030 with project conditions, a significant impact would occur if the project would contribute 5 dB or more of noise. As shown in Table 3.10-17, the project contribution would be 2.5 dB or less to those roadway segments that would experience less than 60 dBA Ldn for the with project conditions, which is within the 5-dB or more threshold. Impacts would be less than significant.

For the roadway segments that would experience 60 or more dBA Ldn for the year 2030 with project conditions, a significant impact would occur if the project would contribute 3 dB or more of noise. As shown in Table 3.10-16, the project contribution to those roadway segments that would experience more than 60 dBA Ldn for the with project condition, would range between 0.0 and 4.7 dB and would exceed the project 3-dB increase threshold at the roadway segments of Tennant Avenue west of Condit Road, Tennant Avenue east of Murphy Avenue, and Murphy Avenue south of Tennant Avenue. This would be considered a significant impact.

The noise levels shown above in Table 3.10-17 are based only on the noise created by each roadway segment and do not consider the entire noise environment, which is often impacted by multiple roadways and stationary sources. When all noise sources are considered, the project contribution to these roadway segments would be reduced; however, it is speculative to assume that consideration of other noise sources would reduce the project impacts to less than significant levels.

Mitigation Measure NOI-1b is provided that would require the City of Morgan Hill to consider reducing the speed limits, restricting trucks, providing other traffic calming measures such as installation of center dividers and narrowing the lane widths, or installing sounds walls or landscaped berms along the roadway segments of Tennant Avenue west of Condit Road; Tennant Avenue east of Murphy Avenue; and Murphy Avenue south of Tennant Avenue. According to Caltrans, a 5-mile-per-hour decrease in vehicle speeds would reduce the noise level between 1 and 2 dB and restricting truck traffic has the potential to provide even greater noise levels reductions; however, it is dependent on how many trucks are currently using these roadway segments.



Implementation of Mitigation Measure NOI-1b has the potential to reduce the roadway noise impacts to less than significant; however, the measures detailed in Mitigation Measure NOI-1b may conflict with other City safety and circulation goals and policies and may not be feasible to implement. Therefore, this would result in a significant unavoidable impact for year 2030 conditions.

High School Site (Project Level) Proposed High School Construction-Related Noise Construction activities associated with development of the proposed High School have the potential to impact surrounding receptors. Construction noise impacts would be a function of the noise generated by construction equipment, equipment location, sensitivity of nearby land uses, and the timing and duration of the construction activities. The nearest sensitive receptor to the proposed High School are single-family homes as near as 70 feet north of the project site.

Section 8.28.040 of the Municipal code limits construction activities to between the hours of 7:00 a.m. and 8:00 p.m., Monday through Friday, and between the hours of 9:00 a.m. and 6:00 p.m. on Saturday, except for Sundays or federal holidays. Through adherence to the limitation of allowable construction times provided in Section 8.28.040 of the Municipal Code, the proposed High School construction-related noise levels would not exceed any standards. Impacts would be less than significant.

Proposed High School Stationary and Other Noise Sources The proposed High School would create stationary and other noise sources from the proposed onsite driveways, parking lots, rooftop mechanical equipment, football and track field, multipurpose field, baseball fields, tennis courts, basketball courts, pool, and plaza.

In order to determine if the proposed High School would exceed the City’s stationary and other noise sources noise standard as detailed at the beginning of this section, the proposed High School’s stationary and other noise sources were modeled separately from the transportation noise sources on public roadways. The noise modeling assumptions and methodology have been previously discussed above in Section 3.10.4 and the results are summarized in Table 3.10-18. The SoundPlan printouts are provided in Appendix G.

Table 3.10-18: Proposed High School Onsite Noise Source Levels at Nearby Sensitive Receptors

Receiver1 Description Stationary Only Noise

Level (dBA Ldn) Noise Standard2

1 Single-family home west of High School 44.9 60 dB Ldn or +5 dB

2 Single-family home northwest of High School 26.0 60 dB Ldn or +5 dB

3 Single-family home northwest of High School 47.7 60 dB Ldn or +5 dB



Table 3.10-18 (cont.): Proposed High School Onsite Noise Source Levels at Nearby Sensitive Receptors

Receiver1 Description Stationary Only Noise

Level (dBA Ldn) Noise Standard2

4 Single-family home north of High School 49.3 60 dB Ldn or +5 dB



7 Single-family home east of High School 41.5 60 dB Ldn or +5 dB

8 Single-family home southeast of High School 42.3 60 dB Ldn or +5 dB

9 Single-family home south of High School 36.8 60 dB Ldn or +5 dB

10 Hotel west of High School 39.7 65 dB Ldn or +5 dB

Notes: 1 Location of Receivers shown on Exhibit 3.10-3. 2 Noise standard based on Section 18.48.075 of the Municipal Code and Policies 7e, 7f, and 7g of the General Plan. Source: Michael Brandman Associates, 2013.

Table 3.10-18 shows that for the stationary and other noise sources scenario, the greatest noise impact would occur at Receiver 4 with noise levels of 49.3 dBA Ldn. These noise levels are within the City’s stationary and other noise sources average noise level threshold of 60 dBA Ldn . Impacts would be less than significant.

Proposed High School Project Roadway Noise The proposed High School would generate additional vehicular trips on roadways in the project vicinity. Noise from motor vehicles is generated by engine vibrations, the interaction between tires and the road, and the exhaust system.

In order to quantify the traffic noise impacts along the analyzed roadways with nearby noise sensitive uses, the roadway noise contours were calculated. Noise contours represent the distance to noise levels of a constant value and are measured from the center of the roadway. For analysis comparison purposes, the Ldn and CNEL noise levels are calculated at the distance to the nearest sensitive receptor, which was determined from aerial photos of the study area. In addition, the distance from the centerline to the 55-, 60-, 65-, and 70-dBA noise levels are calculated for both Ldn and CNEL standards and are shown in the noise calculation spreadsheets provided in Appendix G. The proposed project’s offsite traffic noise impacts have been analyzed for the existing and year 2030 conditions and are discussed below.

Existing Conditions The proposed High School’s potential offsite traffic noise impacts have been calculated through a comparison between the existing without-project scenario and the existing with proposed High School scenario. The results of this comparison are shown in Table 3.10-19.



Table 3.10-19: Proposed High School Project Traffic Noise Contributions for Existing Conditions


Roadway Segment No

ProjectWith

ProjectProject

Contribution


Impact?

Butterfield Boulevard North of Tennant Avenue 57.7 58.0 0.3 No

Juan Hernandez Drive North of Tennant Avenue 54.8 55.0 0.2 No

Condit Road South of Dunne Avenue 55.7 55.7 0.0 No

Condit Road North of Tennant Avenue 53.2 53.2 0.0 No



Murphy Avenue South of Barrett Avenue 45.5 48.7 3.2 No

Murphy Avenue South of Tennant Avenue 53.1 53.1 0.0 No

Dunne Avenue West of US 101 Southbound Ramps 64.9 65.0 0.1

No





Tennant Avenue West of Butterfield Boulevard 65.9 65.9 0.0 No

Tennant Avenue West of US 101 Southbound Ramps 56.7 57.0 0.3

No

Tennant Avenue West of Condit Road 57.0 59.6 2.6 No

Tennant Avenue East of Murphy Avenue 58.4 61.2 2.8 No

Note: 1 Distance to nearest occupied structure shown in Table 3.10-13. Source: Michael Brandman Associates, 2013.

Table 3.10-19 above shows that for the existing conditions, noise level contributions from the proposed High School to the study area roadways would range from 0.0 to 3.4 dBA Ldn. In this scenario, the with project noise levels along the roadway segments of Butterfield Boulevard north of Tennant Avenue; Juan Hernandez Drive north of Tennant Avenue; Condit Road south of Dunne Avenue; Condit Road north of Tennant Avenue; Murphy Avenue south of Dunne Avenue; Murphy Avenue north of Barrett Avenue; Murphy Avenue south of Barrett Avenue; Murphy Avenue south of Tennant Avenue; Barrett Avenue east of Murphy Avenue; Tennant Avenue west of US 101 Southbound Ramps; and Tennant Avenue west of Condit Road are below 60 dB Ldn, where a significant impact would occur if the project increased the noise level by 5 dB or more, in accordance



with General Plan Policy 7e. The project contribution to these roadway segments would be 3.4 dB or less, which is within the 5-dB or more threshold. Impacts would be less than significant.

This scenario also shows that the with project noise levels along the roadway segments of Dunne Avenue west of US 101 Southbound Ramps; Dunne Avenue west of Condit Road; Dunne Avenue west of Murphy Avenue; Dunne Avenue East of Murphy Avenue; Tennant Avenue west of Butterfield Boulevard; and Tennant Avenue east of Murphy Avenue are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more. The project contribution to these roadway segments would be 2.8 dB or less, which is within the 3-dB or more threshold. Impacts would be less than significant.

Year 2030 Conditions The proposed High School’s potential offsite traffic noise impacts have been calculated through a comparison between the year 2030 without-project scenario and the year 2030 with proposed High School project scenario. The results of this comparison are shown in Table 3.10-20.

Table 3.10-20: Proposed High School Project Traffic Noise Contributions for Year 2030 Conditions


Roadway Segment No

ProjectWith

ProjectProject

Contribution


Impact?

Butterfield Boulevard North of Tennant Avenue 61.7 61.9 0.2 No

Juan Hernandez Drive North of Tennant Avenue 61.1 61.2 0.1 No

Condit Road South of Dunne Avenue 57.4 57.4 0.0 No

Condit Road North of Tennant Avenue 55.1 55.1 0.0 No



Murphy Avenue South of Barrett Avenue 48.0 50.1 2.1 No

Murphy Avenue South of Tennant Avenue 54.0 54.0 0.0 No


65.3 65.4 0.1 No





Tennant Avenue West of Butterfield Boulevard 66.0 66.1 0.1 No



Table 3.10-20 (cont.): Proposed High School Project Traffic Noise Contributions for Year 2030 Conditions


Roadway Segment No

ProjectWith

ProjectProject

Contribution


Impact?


59.3 59.4 0.1 No

Tennant Avenue West of Condit Road 58.7 60.5 1.8 No

Tennant Avenue East of Murphy Avenue 60.7 62.5 1.8 No

Note: 1 Distance to nearest occupied structure shown in Table 3.10-13. Source: Michael Brandman Associates, 2013.

Table 3.10-20 above shows that for the year 2030 conditions, noise level contributions from the proposed High School to the study area roadways would range from 0.0 to 2.1 dBA Ldn. In this scenario, the with project noise levels along the roadway segments of Condit Road south of Dunne Avenue; Condit Road north of Tennant Avenue; Murphy Avenue north of Barrett Avenue; Murphy Avenue south of Barrett Avenue; Murphy Avenue south of Tennant Avenue; Barrett Avenue east of Murphy Avenue; and Tennant Avenue west of US 101 Southbound Ramps are below 60 dB Ldn, where a significant impact would occur if the project increased the noise level by 5 dB or more, in accordance with General Plan Policy 7e. The project contribution to these roadway segments would be 2.1 dB or less, which is within the 5-dB or more increase threshold. Impacts would be less than significant.

This scenario also shows that the with project noise levels along the roadway segments of Butterfield Boulevard north of Tennant Avenue; Juan Hernandez Drive north of Tennant Avenue; Murphy Avenue south of Dunne Avenue; Dunne Avenue west of US 101 Southbound Ramps; Dunne Avenue west of Condit Road; Dunne Avenue west of Murphy Avenue; Dunne Avenue East of Murphy Avenue; Tennant Avenue west of Butterfield Boulevard; Tennant Avenue west of Condit Road; and Tennant Avenue east of Murphy Avenue are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more, as outlined in General Plan Policy 7e. The project contribution to these roadway segments would be 2 dB or less, which is within the 3 dB or more increase threshold. Impacts would be less than significant.

Combined Offsite Roadway and Onsite Noise The proposed project may create potential noise impacts at the nearby sensitive receptors from the proposed onsite driveways, parking lots, rooftop mechanical equipment, football and track field, multipurpose field, baseball fields, tennis courts, basketball courts, pool, and plaza, as well as from project-generated vehicle trips on the nearby roads. The noise modeling assumptions and



methodology for the combined offsite road and onsite noise have been previously discussed above in Section 3.10.4. The project study area for this analysis was limited to the area where the onsite noise sources have the potential to exceed the ambient noise levels at the nearby sensitive receptors.

The proposed High School’s combined offsite roadway and onsite noise impacts have been analyzed using the SoundPlan Model for the existing and year 2030 conditions. The results are summarized in Table 3.10-21. The SoundPlan printouts are provided in Appendix G. Exhibit 3.10-5 shows the existing with proposed highs school noise contours. Exhibit 3.10-6 shows the year 2030 without project noise contours. Exhibit 3.10-7 shows the year 2030 with proposed High School noise contours.

Table 3.10-21: Proposed High School’s Combined Offsite Roadway on Onsite Noise Sources Contributions

Existing (dBA Ldn) Year 2030 (dBA Ldn)

Receiver1 Description No

Project With

Project IncreaseNo

Project With

Project Increase

1 Single-family home west of High School

50.5 53.7 3.2 53.0 54.8 1.8

2 Single-family home northwest of High School

59.1 61.5 2.4 62.1 62.6 0.5

3 Single-family home northwest of High School

55.8 58.6 2.8 58.4 59.8 1.4

4 Single-family home north of High School

54.0 57.0 3.0 56.2 58.2 2.0


53.1 54.3 1.2 55.3 56.0 0.7


51.8 52.8 1.0 54.1 54.6 0.5

7 Single-family home east of High School

58.9 59.0 0.1 61.1 61.2 0.1

8 Single-family home southeast of High School

65.3 65.4 0.1 67.6 67.6 0.0

9 Single-family home south of High School

54.8 55.1 0.3 55.8 56.0 0.2

10 Hotel west of High School 60.2 62.1 1.9 61.8 63.2 1.4 Note: 1 Location of Receivers shown on Exhibit 3.10-5. Source: Michael Brandman Associates, 2013.

Table 3.10-21 shows that for the existing and year 2030 conditions, noise level contributions from the proposed High School to the analyzed receivers would range from 0.0 to 3.2 dBA Ldn. In the existing scenario, the with proposed High School noise levels at Receivers 1, 3, 4, 5, 6, 7, and 9 are less than the 60 dBA Ldn where a significant impact would occur if the project increased the noise level by 5 dB or more. The project contribution to these Receivers would be 3.2 dB or less, which is within the



threshold outlined in General Plan Policy 7e. Impacts would be less than significant. The existing scenario also shows that the with project noise levels at Receivers 2, 8, and 10 are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more. The project contribution to these Receivers would be 2.4 dB or less, which is within the threshold. Impacts would be less than significant for the existing conditions.

In the year 2030 scenario, the with proposed High School noise levels at Receivers 1, 3, 4, 5, 6, and 9 are less than the 60 dBA Ldn, where a significant impact would occur if the project increased the noise level by 5 dB or more. The project contribution to these Receivers would be 2.0 dB or less, which is within the threshold. Impacts would be less than significant. The year 2030 scenario also shows that the with project noise levels at Receivers 2, 7, 8, and 10 are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more, in accordance with General Plan Policy 7e. The project contribution to these Receivers would be 1.4 dB or less, which is within the threshold. Impacts would be less than significant for the year 2030 conditions.

Level of Significance Before Mitigation

SEQ Area (Program Level) Potentially significant impact.

High School Site (Project Level) Less than significant impact.

Mitigation Measures

MM NOI-1a SEQ Area. As part of the Conditional Use Permit or Design Permit Application (whichever comes first), the City of Morgan Hill shall require applicants proposing to develop new uses within the SEQ Area to submit a noise impact analysis that analyzes each project’s potential onsite stationary and other noise sources noise impacts to nearby sensitive receptors at the time of entitlement for each project. The noise impact analysis shall demonstrate through the incorporation of mitigation, if required, that the proposed onsite stationary and other noise sources would not exceed the City’s noise standards. All mitigations identified in the noise impact analysis shall be incorporated into the permit as conditions of the project.

MM NOI-1b SEQ Area. Prior to consideration of approval of any urban development within the SEQ Area, the City of Morgan Hill shall evaluate (1) reducing the speed limits, (2) implementing truck restrictions, (3) providing traffic calming measures such as center medians or narrowing the lane widths, or (4) installing sounds walls or landscaped berms along the roadway segments of:

(A) Tennant Avenue west of Condit Road; (B) Tennant Avenue east of Murphy Avenue; and (C) Murphy Avenue south of Tennant Avenue.



Level of Significance After Mitigation SEQ Area (Program Level) Significant unavoidable impact.


Construction and Operational Vibration

Impact NOI-2: Construction and operational activities associated with the proposed project would not generate substantial groundborne vibration or groundborne noise levels.

Impact Analysis

The following section analyzes the potential vibration impacts associated with the construction and operations of the proposed development projects within the SEQ Area and proposed High School project and compares the vibration levels with City and other agency standards.

Vibration Standards Section 18.48.135 of the Municipal Code restricts any sources of vibration that is discernible without instruments at the lot line. Since the City does not provide a quantifiable vibration threshold that may be utilized to analyze the proposed projects vibration impacts, the vibration impact thresholds were based on Caltrans thresholds presented in its Transportation- and Construction-Induced Vibration Guidance Manual. The report recommends a threshold of 0.25 inch per second PPV as the significance level for continuous events, near residential structures during construction activities and a threshold of 0.04 inch per second PPV for transient sources during operational activities.

SEQ Area (Program Level) Construction-Related Vibration Construction activities can produce vibration that may be felt by adjacent uses. The construction of the development projects within SEQ Area and city-initiated land use changes would not include hillside construction, or construction in bogs that would require the use of equipment such as pile drivers, which are known to generate substantial construction vibration levels.

The primary sources of vibration during construction would be from bulldozers and graders. From Table 3.10-15, a large bulldozer would produce the largest amount of construction-related vibration on the development sites within the SEQ Area of 0.089 inch per second PPV at 25 feet.

The nearest sensitive receptor to the Craiker Sports Retail and Restaurant Uses is a hotel use as near as 100 feet south of the property. The nearest sensitive receptor to the Puliafico SRL Uses is a single-family home as near as 95 feet north of the property. The nearest sensitive receptor to the Jacoby SRL Uses is a single-family home as near as 220 feet east of the property. The nearest sensitive receptors to the Chiala Planned Development are several single-family homes located as near as 50 feet to the property.

Tennant Avenue

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-101

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Barrett A

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Michael Brandman Associates

20860001 • 11/2013 | 3.10-5_existing_w_prop_HS_NC.cdr CITY OF MORGAN HILLCITYWIDE AGRICULTURE PRESERVATION PROGRAM AND SOUTHEAST QUADRANT LAND USE PLAN

ENVIRONMENTAL IMPACT REPORT

Exhibit 3.10-5Existing With Proposed

High School Noise Contour Map

Source: SoundPlan Version 7.2

Tennant Avenue

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Proposed HighSchool Site

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Barrett A

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20860001 • 11/2013 | 3.10-6_2030_wo_proj_NC.cdr CITY OF MORGAN HILLCITYWIDE AGRICULTURE PRESERVATION PROGRAM AND SOUTHEAST QUADRANT LAND USE PLAN


Exhibit 3.10-6Year 2030 Without

Project Noise Contour Map


Tennant Avenue

US

-101

1

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34

56

7

Barrett A

venue

Murp

hy A

venue

8

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20860001 • 11/2013 | 3.10-7_2030_w_proposed_HS_NC.cdr CITY OF MORGAN HILLCITYWIDE AGRICULTURE PRESERVATION PROGRAM AND SOUTHEAST QUADRANT LAND USE PLAN


Exhibit 3.10-7Year 2030 With Proposed

High School Noise Contour Map




Based on the above four projects, the nearest offsite sensitive receptors of all four projects are the single-family homes located as near as 50 feet from the Chiala Planned Development. Based on typical vibration propagation rates, a large bulldozer would create a vibration level of up to 0.042 inch per second PPV at 50 feet. This vibration level would not exceed the 0.25-inch-per-second PPV significance threshold for continuous events, near residential structures during construction activities. This impact would be less than significant.

Operations-Related Vibration The operation of the development projects within the SEQ Area may result in the development of onsite roadways for delivery trucks. Based on the distances to the nearest receptors from each of the four projects detailed above in the construction-related vibration analysis, there is a potential that an onsite road is developed as near as 50 feet to the nearest sensitive receptor. (Note that this distance would be representative of other portions of the SEQ Area).

From Table 3.10-15, a loaded truck on an unimproved road would typically produce a vibration level of 0.076 inch per second PPV at 25 feet. Based on typical vibration propagation rates, a loaded truck would create a vibration level of up to 0.035 inch per second PPV at 50 feet. This vibration level would not exceed the 0.04-inch-per-second PPV significance threshold for transient events during operational activities. This impact would be less than significant.

High School Site (Project Level) Construction-Related Vibration Construction activities can produce vibration that may be felt by adjacent uses. The construction of the proposed High School would not require the use of equipment such as pile drivers, which are known to generate substantial construction vibration levels.

The primary sources of vibration during construction would be from bulldozers and graders. From Table 3.10-15, a large bulldozer would produce the largest amount of construction-related vibration on the proposed High School site of 0.089 inch per second PPV at 25 feet.

The nearest sensitive receptor to the proposed High School are single-family homes as near as 70 feet north of the project site. Based on typical vibration propagation rates, a large bulldozer would create a vibration level of up to 0.029 inch per second PPV at 70 feet. This vibration level would not exceed the 0.25-inch-per-second PPV significance threshold for continuous events, near residential structures during construction activities, as established in the Transportation- and Construction-Induced Vibration Guidance Manual. This impact would be less than significant.

Operations-Related Vibration The proposed High School project would not introduce any new sources of vibration into the project study area. Impacts would be less than significant.



Level of Significance Before Mitigation SEQ Area (Program Level) Less than significant impact.


Mitigation Measures

No mitigation is necessary.

Level of Significance After Mitigation SEQ Area (Program Level) Less than significant impact.


Permanent Increase in Noise Levels

Impact NOI-3: The operation of the proposed project would create a substantial permanent increase in noise levels.

Impact Analysis

The operation of the proposed development projects within the SEQ Area and proposed High School project may create onsite stationary and other noise sources noise impacts, roadway noise impacts, or a combination of roadway and onsite noise impacts in the immediate vicinity of the project site.

Noise Standards The City has developed the following noise standards for onsite stationary and other noise sources, and roadway noise and combined road and stationary noise, which are detailed below.

Onsite Stationary and Other Noise Sources The City of Morgan Hill Policies 7f and 7g state that stationary noise sources and other noise sources such as ballfields would create a significant noise impact if they would substantially exceed ambient noise levels. The City of Morgan Hill Municipal Code Section 18.48.075 specifies maximum exterior noise levels at the lot line of the adjacent use of 75 dBA for industrial uses, 65 dBA for office, retail or sensitive industries and 60 dBA for residential, park, or institutional uses.

Since Policies 7f and 7g do not quantify what is a substantial noise increase, the substantial increase standard of a 5 dB increase where the with project noise level is less than 60 dBA Ldn, which has been provided in Policy 7e has been utilized in analyzing stationary noise impacts in addition to the noise standards provided in Municipal Code Section 18.48.075.



Roadway Noise and Combined Road and Stationary Noise The City of Morgan Hill General Plan Policy 7e states that traffic noise increases from a proposed project shall be considered significant if: a) the noise level increase is 5 dBA Ldn or greater, with a future noise level of less than 60 dBA Ldn, or b) the noise level increase is 3 dBA Ldn or greater, with a future noise level of 60 dBA Ldn or greater.

SEQ Area (Program Level) SEQ Area Project Stationary and Other Noise Sources The analysis provided above in Impact NOI-1 found that the SEQ Area development plans have not yet been designed; therefore, it is unknown what, if any, stationary and other noise sources would exist at future development sites, as well as the distances of these noise sources to nearby sensitive receptors, which is required to provide a quantitative analysis of noise impacts. Although it is too speculative to quantify the SEQ Area project stationary and other noise source impacts, there is a potential that the SEQ Area project could create stationary noise levels that would create a substantial permanent increase in noise levels. This would be considered a significant impact.

Mitigation Measure NOI-1a is provided that would require applicants proposing to develop within the SEQ Area in the future to submit a noise impact analysis that analyzes each project’s potential stationary and other noise sources noise impacts to nearby sensitive receptors at the time of entitlement for each project. Several feasible mitigation measures and project design features, including source placement, limitation on operational hours, and sound walls are available to reduce any potential stationary noise impacts to within City standards. Impacts would be reduced to less than significant with implementation of Mitigation Measure NOI-1a.

SEQ Area Roadway Noise The development projects within the SEQ Area would generate additional vehicular trips on roadways in the project vicinity. Noise from motor vehicles is generated by engine vibrations, the interaction between tires and the road, and the exhaust system. The SEQ Area offsite traffic noise impacts have been analyzed for the existing and year 2030 conditions and are discussed below.

Existing Conditions The development projects within the SEQ Area potential offsite traffic noise impacts have been calculated above in Impact NOI-1 for the existing conditions. The results of this comparison are shown in Table 3.10-16.

The analysis provided above in Impact NOI-1 shows that for the existing conditions, noise level contributions from the development projects within the SEQ Area to the study area roadways would range from 0.0 to 7.0 dBA Ldn. For the roadway segments that would experience less than 60 dBA Ldn for the with project conditions, a significant impact would occur if the project would contribute 5 dB or more of noise. As shown in Table 3.10-16, the project contribution would be 4.2 dB or less to



those roadway segments that would experience less than 60 dBA Ldn for the with project condition, which is within the 5-dB or more threshold. Impacts would be less than significant.

For the roadway segments that would experience 60 or more dBA Ldn for the with project conditions,

a significant impact would occur if the project would contribute 3 dB or more of noise. As shown in Table 3.10-16, the project contribution to those roadway segments that would experience more than 60 dBA Ldn for the with project condition would range between 0.2 and 7.0 dB and would exceed the 3-dB increase threshold at the roadway segments of Tennant Avenue west of Condit Road, Tennant Avenue east of Murphy Avenue, and Murphy Avenue south of Tennant Avenue. This would be considered a significant impact.

The noise levels shown above in Table 3.10-16 are based only on the noise created by each roadway segment and do not consider the entire noise environment, which is often impacted by multiple roadways and stationary sources. When all noise sources are considered the project contribution to these roadway segments would be reduced; however, it is speculative to assume that consideration of other noise sources would reduce the project impacts to less than significant levels.

Mitigation Measure NOI-1b is provided above in Impact NOI-1 that would require the City of Morgan Hill to consider reducing the speed limits, restrict trucks, provide other traffic calming measures such as installation of center dividers and narrowing the lane widths, or install soundwalls or landscaped berms along the roadway segments of Tennant Avenue west of Condit Road; Tennant Avenue east of Murphy Avenue; and Murphy Avenue south of Tennant Avenue. According to Caltrans, a 5-mile-per-hour decrease in vehicle speeds would reduce the noise level between 1 and 2 dB, and restricting truck traffic has the potential to provide even greater noise levels reductions; however, it is dependent on how many trucks are currently using these roadway segments.

Implementation of Mitigation Measure NOI-1b has the potential to reduce the roadway noise impacts to less than significant; however, the measures detailed in Mitigation Measure NOI-1b may conflict with other City safety and circulation goals and policies and may not be feasible to implement. Therefore, this would result in a significant unavoidable impact for existing conditions.

Year 2030 Conditions The development projects within the SEQ Area potential offsite traffic noise impacts have been calculated above in Impact NOI-1 for the year 2030 conditions. The results of this comparison are shown in Table 3.10-17.

The analysis provided above in Impact NOI-1 shows that for the year 2030 conditions, noise level contributions from the development projects within the SEQ Area to the study area roadways would range from 0.0 to 4.7 dBA Ldn. For the roadway segments that would experience less than 60 dBA Ldn for the year 2030 with project conditions, a significant impact would occur if the project would contribute 5 dB or more of noise. As shown in Table 3.10-17, the project contribution would be 2.5



dB or less to those roadway segments that would experience less than 60 dBA Ldn for the with project conditions, which is within the 5-dB or more threshold. Impacts would be less than significant.

For the roadway segments that would experience 60 or more dBA Ldn for the year 2030 with project conditions, a significant impact would occur if the project would contribute 3 dB or more of noise. As shown in Table 3.10-16, the project contribution to those roadway segments that would experience more than 60 dBA Ldn for the with project condition, would range between 0.0 and 4.7 dB and would exceed the project 3-dB increase threshold at the roadway segments of Tennant Avenue west of Condit Road; Tennant Avenue east of Murphy Avenue, and Murphy Avenue south of Tennant Avenue. This would be considered a significant impact.

The noise levels shown in Table 3.10-17 are based only on the noise created by each roadway segment and do not consider the entire noise environment, which is often impacted by multiple roadways and stationary sources. When all noise sources are considered the project contribution to these roadway segments would be reduced; however, it is speculative to assume that consideration of other noise sources would reduce the project impacts to less than significant levels.

Mitigation Measure NOI-1b is provided above in Impact NOI-1 that would require the City of Morgan Hill to consider reducing the speed limits, restrict trucks, provide other traffic calming measures such as installation of center dividers and narrowing the lane widths, or install soundwalls or landscaped berms along the roadway segments of Tennant Avenue west of Condit Road; Tennant Avenue east of Murphy Avenue; and Murphy Avenue south of Tennant Avenue. According to Caltrans, a 5-mile-per-hour decrease in vehicle speeds would reduce the noise level between 1 and 2 dB and restricting truck traffic has the potential to provide even greater noise levels reductions; however, it is dependent on how many trucks are currently using these roadway segments.

Implementation of Mitigation Measure NOI-1b has the potential to reduce the roadway noise impacts to less than significant; however, the measures detailed in Mitigation Measure NOI-1b may conflict with other City safety and circulation goals and policies and may not be feasible to implement. Therefore, this would result in a significant unavoidable impact for year 2030 conditions.

High School Site (Project Level) Proposed High School Stationary and Other Noise Sources The proposed High School would create onsite noise sources from the proposed onsite driveways, parking lots, rooftop mechanical equipment, football and track field, multipurpose field, baseball fields, tennis courts, basketball courts, pool, and plaza that would have the potential to create a substantial permanent increase in noise levels at the nearby residential uses in the project vicinity. The noise impacts to the sensitive receptors at the proposed High School were not analyzed because the setback of the proposed High School’s structures from Tennant Avenue and Murphy Avenue would be sufficient to preclude the potential of an exceedance of a noise standard at the proposed High School structures.



The analysis provided above in Impact NOI-1 analyzed the potential increases in average noise level from onsite activities at the proposed High School and the results are shown above in Table 3.10-18. Table 3.10-18 shows that the greatest noise impact would occur at Receiver 4 with a noise level of 49.3 dBA Ldn. These noise levels are within the City’s stationary and other noise sources average noise level threshold of 60 dBA Ldn . Impacts would be less than significant.

Proposed High School Project Roadway Noise The proposed High School would generate additional vehicular trips on roadways in the project vicinity. Noise from motor vehicles is generated by engine vibrations, the interaction between tires and the road, and the exhaust system. The proposed High School offsite traffic noise impacts have been analyzed for the existing and year 2030 conditions and are discussed below.

Existing Conditions The proposed High School’s potential offsite traffic noise impacts have been calculated above in Impact NOI-1 for the existing conditions. The results of this comparison are shown in Table 3.10-19.

The analysis provided above in Impact NOI-1 shows that for the existing conditions, noise level contributions from the proposed High School to the study area roadways would range from 0.0 to 3.4 dBA Ldn. In this scenario, the with project noise levels along the roadway segments of Butterfield Boulevard north of Tennant Avenue; Juan Hernandez Drive north of Tennant Avenue; Condit Road south of Dunne Avenue; Condit Road north of Tennant Avenue; Murphy Avenue south of Dunne Avenue; Murphy Avenue north of Barrett Avenue; Murphy Avenue south of Barrett Avenue; Murphy Avenue south of Tennant Avenue; Barrett Avenue east of Murphy Avenue; Tennant Avenue west of US 101 Southbound Ramps; and Tennant Avenue west of Condit Road are below 60 dB Ldn, where a significant impact would occur if the project increased the noise level by 5 dB or more. The project contribution to these roadway segments would be 3.4 dB or less, which is within the 5-dB or more threshold outlined in General Plan Policy 7e. Impacts would be less than significant.

This scenario also shows that the with project noise levels along the roadway segments of Dunne Avenue west of US 101 Southbound Ramps; Dunne Avenue west of Condit Road; Dunne Avenue west of Murphy Avenue; Dunne Avenue East of Murphy Avenue; Tennant Avenue west of Butterfield Boulevard; and Tennant Avenue east of Murphy Avenue are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more. The project contribution to these roadway segments would be 2.8 dB or less, which is within the 3-dB or more threshold. Impacts would be less than significant.

Year 2030 Conditions The proposed High School’s potential offsite traffic noise impacts have been calculated above in Impact NOI-1 for the year 2030 conditions. The results of this comparison are shown in Table 3.10-20.



The analysis provided above in Impact NOI-1 shows that for the year 2030 conditions, noise level contributions from the proposed High School to the study area roadways would range from 0.0 to 2.1 dBA Ldn. In this scenario, the with project noise levels along the roadway segments of Condit Road south of Dunne Avenue; Condit Road north of Tennant Avenue; Murphy Avenue north of Barrett Avenue; Murphy Avenue south of Barrett Avenue; Murphy Avenue south of Tennant Avenue; Barrett Avenue east of Murphy Avenue; and Tennant Avenue west of US 101 Southbound Ramps are below 60 dB Ldn, where a significant impact would occur if the project increased the noise level by 5 dB or more, as outlined in General Plan Policy 7e. The project contribution to these roadway segments would be 2.1 dB or less, which is within the 5-dB or more increase threshold. Impacts would be less than significant.

This scenario also shows that the with project noise levels along the roadway segments of Butterfield Boulevard north of Tennant Avenue; Juan Hernandez Drive north of Tennant Avenue; Murphy Avenue south of Dunne Avenue; Dunne Avenue west of US 101 Southbound Ramps; Dunne Avenue west of Condit Road; Dunne Avenue west of Murphy Avenue; Dunne Avenue East of Murphy Avenue; Tennant Avenue west of Butterfield Boulevard; Tennant Avenue west of Condit Road; and Tennant Avenue east of Murphy Avenue are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more. The project contribution to these roadway segments would be 1.8 dB or less, which is within the 3-dB or more increase threshold. Impacts would be less than significant.

Combined Offsite Roadway and Onsite Noise The proposed project may create potential noise impacts at the nearby sensitive receptors from the proposed onsite driveways, parking lots, rooftop mechanical equipment, football and track field, multipurpose field, baseball fields, tennis courts, basketball courts, pool, and plaza as well as from the project generated vehicle trips on the nearby roads. The project study area for this analysis was limited to the area where the onsite noise sources have the potential to exceed the ambient noise levels at the nearby sensitive receptors.

The proposed project’s combined offsite roadway and onsite noise impacts have been analyzed above in Impact NOI-1 for the existing and year 2030 conditions. The results of this comparison are shown in Table 3.10-21.

The analysis provided above in Impact NOI-1 shows that for the existing and year 2030 conditions, noise level contributions from the proposed High School to the analyzed receivers would range from 0.0 to 3.2 dBA Ldn. In the existing scenario, the with proposed High School noise levels at Receivers 1, 3, 4, 5, 6, 7, and 9 are less than the 60 dBA Ldn where a significant impact would occur if the project increased the noise level by 5 dB or more. The project contribution to these Receivers would be 3.2 dB or less, which is within the threshold established in General Plan Policy 7e. Impacts would be less than significant. The existing scenario also shows that the with project noise levels at Receivers 2, 8, and 10



are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more. The project contribution to these Receivers would be 2.4 dB or less, which is within the threshold. Impacts would be less than significant for the existing conditions.

In the year 2030 scenario, the with proposed High School noise levels at Receivers 1, 3, 4, 5, 6, and 9 are less than the 60 dBA Ldn where a significant impact would occur if the project increased the noise level by 5 dB or more. The project contribution to these Receivers would be 2.0 dB or less, which is within the threshold. Impacts would be less than significant. The year 2030 scenario also shows that the with project noise levels at Receivers 2, 7, 8, and 10 are 60 dB Ldn or greater, where a significant impact would occur if the project increased the noise level by 3 dB or more, in accordance with General Plan Policy 7e. The project contribution to these Receivers would be 1.4 dB or less, which is within the threshold. Impacts would be less than significant for the year 2030 conditions.


SEQ Area (Program Level) Potentially significant impact.


Mitigation Measures

SEQ Area (Program Level) Implement Mitigation Measures NOI-1a and NOI-1b.

High School Site (Project Level) No mitigation is necessary.

Level of Significance After Mitigation SEQ Area (Program Level) Significant unavoidable impact.


Temporary Increase in Noise Levels

Impact NOI-4: Construction and operation of the proposed project would not create a substantial temporary increase in ambient noise levels in the project vicinity above levels existing without the project.

Impact Analysis

The proposed development projects within the SEQ Area and proposed High School project may create a substantial temporary increase in noise levels above ambient noise levels from construction-related activities.



Noise Standards The City of Morgan Hill Municipal Code Section 8.28.040 generally prohibits construction activities other than between the hours of 7:00 a.m. and 8:00 p.m. Monday through Friday and between the hours of 9:00 a.m. and 6:00 p.m. on Saturday. Construction activities may not occur on Sundays or federal holidays. However, the City construction noise standards do not provide any limits to the noise levels that may be created during construction activities at the nearby sensitive receptors and even with adherence to the City standards, the resultant construction noise levels may result in a significant substantial temporary noise increase at the nearby sensitive receptors.

In order to determine if the proposed construction activities would create a significant substantial temporary noise increase, the OSHA agency limits for noise exposure have been utilized. The use of a significance threshold using an OSHA standard is considered conservative. The OSHA standard limits noise exposure of workers to 90 dB or less over 8 continuous hours and this standard has been utilized to analyze the construction noise impacts to the sensitive receptors located at the nearby offsite residences.

SEQ Area (Program Level) Noise impacts from construction activities associated with development of the Craiker Sports Retail and Restaurant Uses, Puliafico SRL Uses, Jacoby SRL Uses, Chiala Planned Development, and city-initiated land use changes, which are part of the SEQ Area program level analysis, were evaluated. Construction noise impacts would be a function of the noise generated by construction equipment, equipment location, sensitivity of nearby land uses, and the timing and duration of the construction activities.

The nearest sensitive receptor to the Craiker Sports Retail and Restaurant Uses is a hotel use as near as 100 feet south of the property. The nearest sensitive receptor to the Puliafico SRL Uses is a single-family home as near as 95 feet north of the property. The nearest sensitive receptor to the Jacoby SRL Uses is a single-family home as near as 220 feet east of the property. The nearest sensitive receptors to the Chiala Planned Development are various single-family homes located as near as 50 feet to the property.

The construction activities are anticipated to include demolition of the existing structures on the Puliafico SRL property and some existing structures on the Chiala Planned Development property as well as site preparation, grading, building construction, paving of new parking lots and internal roadways and application of architectural coatings on all four development sites. These sites provide a representation of construction noise impacts at other properties within the SEQ Area.

Construction noise impacts to the nearby sensitive receptors have been calculated according to the equipment lists for each phase, noise level, and usage factor listed in Table 3.10-4 and using the RCNM Model. Since Table 3.10-4 provides a construction equipment list based on the development projects within the SEQ Area being built simultaneously, it is unknown how many pieces of



equipment would be working on each individual site. Therefore, in order to provide a conservative analysis, it was assumed that one piece of each type of equipment would operate at each site and would be placed 50 feet apart. A summary of the results of the noise impacts associated with development projects within the SEQ Area is provided in Table 3.10-22.

Table 3.10-22: SEQ Area Construction Noise Impacts at Nearby Receptors

Receptor Description

Distance from Nearest Receptor to

Activity (feet)

Construction Noise Level

(dBA Leq)

Demolition Single-family home north of Puliafico SRL 250 70 Single-family home south and west of Chiala Planned Development

90 78

Site Preparation Hotel south of Craiker Sports Retail and Restaurant 100 74 Single-family home north of Puliafico SRL 95 75 Single-family home east of Jacoby SRL 220 68 Single-family home west of Chiala Planned Development 50 79 Grading Hotel south of Craiker Sports Retail and Restaurant 100 75 Single-family home north of Puliafico SRL 95 76 Single-family home east of Jacoby SRL 220 70 Single-family home west of Chiala Planned Development 50 80 Building Construction Hotel south of Craiker Sports Retail and Restaurant 100 73 Single-family home north of Puliafico SRL 95 76 Single-family home east of Jacoby SRL 220 70 Single-family home west of Chiala Planned Development 50 80 Architectural Coatings Hotel south of Craiker Sports Retail and Restaurant 100 68 Single-family home north of Puliafico SRL 95 68 Single-family home east of Jacoby SRL 220 61 Single-family home west of Chiala Planned Development 50 74 Source: FHWA Roadway Construction Noise Model (RCNM), Version 1.1; U.S. Department of Transportation, 2006.

Table 3.10-22 shows that the greatest noise impacts would occur during grading and building construction activities, with noise levels as high as 80 dBA Leq at the nearest offsite residential uses, and Table 3.10-23 shows that the noise levels from each phase of construction activities would be within the 90 dB threshold detailed above. SEQ Area construction noise impacts would be less than significant.



High School Site (Project Level) Construction activities associated with development of the proposed High School have the potential to impact surrounding receptors. Construction noise impacts would be a function of the noise generated by construction equipment, equipment location, sensitivity of nearby land uses, and the timing and duration of the construction activities. The nearest sensitive receptor to the proposed High School are single-family homes as near as 70 feet north of the project site.

The construction activities for the proposed High School are anticipated to include demolition of the existing structures, site preparation, grading, building construction, paving of new parking lots and internal roadways and application of architectural coatings. Construction noise impacts to the nearby sensitive receptors have been calculated according to the equipment lists for each phase, noise level and usage factor listed in Table 3.10-5 and using the RCNM Model. A summary of the results of the noise impacts associated with the construction of the proposed High School project is provided in Table 3.10-23.

Table 3.10-23: Proposed High School Construction Noise Impacts at Nearby Receptors

Construction Phase

Distance from Nearest Receptor to

Activity (feet) Calculated

Construction Noise Level

(dBA Leq)

Demolition 250 71 75

Site Preparation 70 78 75

Grading 70 78 75

Building Construction 600 64 75

Architectural Coating 600 52 75 Source: FHWA Roadway Construction Noise Model (RCNM), Version 1.1; U.S. Department of Transportation, 2006.

Table 3.10-23 shows that the greatest noise impacts would occur during site preparation and grading activities for the Proposed High School, with noise levels as high as 78 dBA Leq at the nearest offsite residential uses. Table 3.10-23 shows that the noise levels from each phase of construction activities would be within the 90 dB threshold detailed above. The Proposed High School construction noise impacts would be less than significant.


SEQ Area (Program Level) Less than significant impact.




Mitigation Measures SEQ Area (Program Level) No mitigation is necessary.

High School Site (Project Level) No mitigation is necessary.

Level of Significance After Mitigation SEQ Area (Program Level) Less than significant impact.


Table 3.10-6: SoundPlan Model Existing Roadway Parameters

Documents

Transcript of Table 3.10-6: SoundPlan Model Existing Roadway Parameters