However, it is reasonable to assume that for a large-scale distribution center, several trucks may occasionally operate simultaneously. The nighttime hour with the largest truck trip generation (6:00 a.m. to 7:00 a.m.) is estimated to result in 42 hourly truck trips (Arup, 2024). Considering the proposed building plan and the length of each loading dock, approximately one fifth of these trips would be distributed to the two southern-most buildings on Parcel 2 (see Figure 4). Hence, a total of approximately
15 Buildings would be moderate height (roughly one to two high-bay levels, or 60 feet). Up to 50 percent of buildings may reach a height of up to 90 feet to accommodate upper-level commercial or light industrial uses. This analysis conservatively assumes all buildings would be 60- feet-tall.
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8 truck trips (inward and outward) could be expected every hour. Conservatively assuming simultaneous operation of five trucks maneuvering in the loading dock area with operating TRUs, the resulting noise level at 500 feet, which is the closest receptor, would be 37 dBA which would still be below the applicable nighttime noise standard of 55 dBA.
Occasional impact noises from loading and unloading of trailers and closure of trailer doors would also occur. These noises would be of relatively short duration and would occur within the shielded truck areas and would not be expected to further contribute to the noise levels predicted in Table 13.
Back up alarms
Both trucks and forklifts would need to operate back-up alarms to ensure worker safety within the loading dock areas. Backup alarms are mandated by the Occupational Safety and Health Administration (OSHA) on all types of industrial vehicles. The Society of Automotive Engineers (SAE) and OSHA mandate the type of signal and sound level. The standard has become the audible horn or beep at a sound level of 87 to 112 dB at the source (OEM, 2007). The average noise level within this range would be 99.5 dBA. Recent developments in technology have minimized the sound level output such as programming the sound level at a designated increase over ambient levels. Given the wide range of reference sound levels and recent improvements over the years, ESA selected the average noise level of 99.5 dBA for analysis. For comparison, ESA also analyzes a higher noise level of 105 dBA for a more conservative analysis.
The nearest noise-sensitive receptors to the loading dock area are residential uses on Calle del Mundo, located approximately 20 feet from the property line of the proposed industrial buildings and an additional 500 feet from the nearest loading dock areas. It is noted, as shown in Table 1, that the existing average nighttime hourly noise level monitored at the eastern and southern property lines adjacent to receptors was 53 to 54 dBA. According to the City Noise Ordinance, if the measured ambient noise level at any given location differs from those levels set forth in City Code 9.10.040, Schedule A, the allowable noise exposure standard shall be adjusted in five dBA increments in each category as appropriate to encompass or reflect said ambient noise level. Therefore, the applicable nighttime noise standard at the nearest noise-sensitive receptors would be 55 dBA.
In addition, as discussed above, the proposed buildings would serve as a barrier to noise within the loading dock areas where trucks would back into the docks. The southernmost buildings are designed with loading docks exposed on the northern side of the buildings. In this configuration, the buildings would serve as a noise barrier for the residential uses on Calle del Mundo to the south. The Barrier Performance Module developed by the department of Housing and Urban Development was used to estimate the degree of acoustical shielding provided by the proposed 60-foot structures. Module output indicates a net noise reduction of 16 dBA, conservatively assuming an off-site receptor at a seventh story height (77 feet).
Application of stationary noise source propagation equations for the backup alarm noise results in a predicted noise level of 42 dBA at 520 feet from the source assuming a source reference noise level of the average of published noise generation (99.5 dBA) and 16 dBA of attenuation from the building structure.
If the higher noise generation reference level (105 dBA) is assumed, the backup alarm noise.
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However, it is reasonable to assume that, at times, several back-up alarms could be in operation simultaneously. As discussed above, the nighttime hour with the largest truck trip generation (6:00 a.m. to 7:00 a.m.) would result in 42 hourly truck trips (ARUP, 2024). While most of these trucks would likely be leaving the facility at this hour, it may conservatively be assumed that half of the trucks (21 trucks) would be arriving, during which backup alarms would be employed as each truck backs into loading a dock. Considering the proposed building plan and the length of each loading dock, approximately one fifth of these trips, or 4.2 trips per hour, would be distributed to the southern-most buildings on Parcel 2 (see Figure 4). This analysis conservatively assumes 5 trucks could backup simultaneously at the southern-most buildings during the busiest nighttime hour. Under this assumption, the resultant noise level would be 54 dBA at the nearest sensitive receptor, which would be just below the applicable adjusted nighttime noise standard of 55 dBA.
Using this same set of assumptions for the remainder of the buildings on Parcel 2, that approximately 5 trucks may backup simultaneously, the additional resultant noise level would be approximately 50 dBA at the nearest sensitive receptor. The combined noise of ten simultaneous backup alarms on Parcel 2 would result in an aggregate noise level of 55 dBA at the nearest sensitive receptors which would meet but not exceed the adjusted nighttime noise standard.
Noise levels at the nearest receptors to the east are predicted to be 46 dBA and also below the applicable adjusted nighttime noise standard of 55 dBA. Consequently, this program-level analysis indicates that operations under Scheme C would be able to be conducted consistent with the restrictions of the City of Santa Clara noise ordinance and not result in a new significant operational noise impact.
As described in the 2016 EIR, subsequent site development would require application for and approval of one or more Development Area Plans. Development Area Plans would include site-specific design details including building heights and configurations, number and location of truck loading dock doors, and trucking operation details.
A municipal code compliance policy is proposed as part of Scheme C that would require conformity with the City noise standards and ensure implementation of measures to reduce back up alarm noise. Each subsequent development proposal will be required to confirm its capability of compliance with the City of Santa Clara noise ordinance as well as CEQA requirements in the context of Development Area Plan review and approval.
Project-Generated Traffic Noise
Approved Project
Under the Approved Project, Parcel 1 was to be developed with 1.2 million square feet (sf) of office space while Parcel 2 was to be developed with 2.16 million sf of office space. The 2016 EIR found that while roadway noise increased for seven of the eight roadway segments analyzed, the noise level increase was significant at only one roadway segment. Specifically, because roadway noise along the segment of Lafayette Street between Tasman Drive and Hogan Drive would increase by 3.0 dBA to 74.0 dBA, the impact along this segment would be significant (see Table 14, Table 3.6-14 of the 2016 EIR).
Implementation of Mitigation Measure NOI-1.2 was identified to reduce this impact on offsite receptors along the east side of Lafayette Street between Tasman Drive and Hogan Drive to a less than significant level. While a soundwall at this location was preliminarily determined to be feasible by the City, because of future obstacles related to design of the wall could occur to make implementation infeasible, the impact was disclosed as potentially significant and unavoidable.
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TABLE 14
EXISTING AND EXISTING PLUS-APPROVED PROJECT NOISE LEVELS AT ACTUAL DISTANCE TO OFF-SITE
RECEPTORS ALONG POTENTIALLY SIGNIFICANT SEGMENTS FOR THE APPROVED PROJECT Roadway Segment
Approx.
Distance to
Nearest
Receptor (feet)
Existing
Ldn at
Receptor
Distance
Existing plus-
Approved Project
Ldn at Receptor
Distance Difference
Tasman Drive Centennial Boulevard to Calle Del Sol 105 70.0 72.8 2.8 Great America SR-237 to Yerba Buena Way/Great 200 73.5 74.6 1.1 Parkway America Way
Great America Yerba Buena Way/Great America Way 80 73.4 75.6 2.2 Parkway Old Mountain View Alviso Road
Lafayette Street Great America Way to Future Driveway 340 72.3 72.6 0.3 Lafayette Street Calle Del Mundo to Tasman Drive 50 66.0 68.5 2.6 Lafayette Street Tasman Drive to Hogan Drive 55 71.0 74.0 3.0 Lafayette Street Hogan Drive to Hope Drive 55 71.3 74.0 2.8 Lafayette Street Agnew Road to Palm Drive 190 67.0 69.1 2.2 SOURCE: Table 3.6-14 of the City of Santa Clara certified an Environmental Impact Report for the City Place Santa Clara Project. 2016
Scheme C Project
Scheme C would replace the office land uses proposed under the Approved Project with approximately
1.6 million sf of warehouse or manufacturing uses. Overall, the square footage of development would remain the same as the Approved Project. However, the industrial/warehouse uses on Parcels 1 and 2 would generate a higher percentage of heavy trucks than what was considered in the 2016 EIR.
Additionally, the industrial/warehouse uses on Parcels 1 and 2 could operate 24 hours per day and hence increase noise levels during the more sensitive nighttime hours. Therefore, this updated analysis for Scheme C not only considers the increase over background conditions relative to the significance criteria applied in the 2016 EIR but also compares the resultant traffic noise levels to those predicted for the Approved Project in the 2016 EIR, as well as predicts the noise level increases during the 6:00 a.m. to 7:00 a.m. hour which is the nighttime hour during which the most truck trips would be generated.
First the noise generated by background vehicle trips are compared to the noise generated by background plus project vehicle trips. All truck trips of the project increment were conservatively assumed to be heavy trucks. Table 15 presents the results of this analysis. As indicated in the table, no roadways would experience an increase of 3 dBA or more and the impact would not be significant.
In addition to comparing the dBA increase, Table 16 presents the background plus Scheme C noise levels along roadway segments and compares them to the existing plus Approved Project noise levels along the same segments, as presented in the 2016 EIR. As can be seen in Table 16, modeled roadside noise levels are lower for background plus Scheme C than what was predicted for the existing plus Approved Project.
Consequently, implementation of Scheme C would not result in roadside noise levels greater than those that were predicted in the 2016 EIR and would not result in new or more severe traffic noise impacts.
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TABLE 15
TRAFFIC NOISE INCREASES ALONG ROADS IN THE PROJECT VICINITY Roadway Segment Background
Applicable
Increase
Threshold
(dB)
Background
plus Scheme
C Project
dBA
Difference
Significant
Increase?
Weekday Peak-Hour Noise Levels
Lafayette Street North of Great America Way 65.9 3 66.4 0.5 No Lafayette Street between Great America Way and Future
Driveway to Parcel 1
67.5 3 69.0 1.5 No
Lafayette Street South of Future Driveway to Parcel 1 67.5 3 67.8 0.3 No Tasman Drive west of Great America Parkway 67.6 3 69.3 1.7 No Tasman Drive between Great America Parkway and Lick
Mill Boulevard
68.7 3 70.9 2.2 No
Tasman Drive east of Lick Mill Boulevard 69.1 3 70.5 1.4 No Lick Mill Boulevard south of Tasman Drive 64.4 3 65.9 1.5 No Great America Parkway North of Great America Way 71.3 3 73.6 2.3 No Great America Parkway between Great America Way
and Mountain View-Alviso Road
70.8 3 73.0 2.2 No
Great America Parkway between Mountain View-Alviso
Road and Tasman Drive
69.8 3 71.6 1.8 No
Great America Parkway south of Tasman Drive 71.3 3 73.2 1.9 No SR 237 West of Great America Parkway 77.9 3 78.4 0.5 No SR 237 East of Great America Parkway 77.0 3 77.6 0.6 No NOTES: dB = decibels; dBA = A-weighted decibels; NA = not applicable a. There are no existing noise-sensitive land uses along these roadway segments; thus, the impact would be less than significant.
SOURCES: Traffic data compiled by ARUP in 2024, and modeling performed by Environmental Science Associates in 2024.
TABLE 16
EXISTING AND EXISTING PLUS-PROJECT NOISE LEVELS AT ACTUAL DISTANCE TO OFF-SITE RECEPTORS
ALONG POTENTIALLY SIGNIFICANT SEGMENTS FOR THE APPROVED PROJECT Roadway Segment
Approx.
Distance to
Nearest
Receptor (feet)
Existing plus-
Approved
Project L dn from
2016 EIR
Background
plus-Scheme
C Ldn Difference
Tasman Centennial Boulevard to Calle Del Sol 105 72.8 67.7 -5.1 Great SR-237 to Yerba Buena Way 200 74.6 67.6 -7.0
Great Yerba Buena Way/Great America Way to
Old Mountain View Alviso Road
80 75.6 71.0 -4.6
Lafayette Great America Way to Future 340 72.6 64.7 -7.9 Lafayette Calle Del Mundo to Tasman Drive 50 68.5 67.8 -0.7 Lafayette Tasman Drive to Hogan Drive 55 74.0 67.7 -6.3 Lafayette Hogan Drive to Hope Drive 55 74.0 67.7 -6.3
Lafayette Agnew Road to Palm Drive 190 69.1 NA NA
Note: NA = data not available for this segment for Scheme C scenario.
SOURCE: ARUP, 2024 and ESA 2024
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Because industrial/warehouse uses on Parcels 1 and 2 could operate 24 hours per day, an additional analysis was conducted to predict the increase in roadway noise that would occur during the peak nighttime hour (6:00 a.m. to 7:00 a.m.). For this analysis the noise generated by background vehicle trips are compared to the noise generated by background plus Scheme C vehicle trips. All truck trips of the Scheme C increment at this hour were conservatively assumed to be heavy trucks. Table 17 presents the results of this analysis. As indicated in the table, only one roadway (two segments of Great America Parkway) would experience an increase of 3 dBA or more. However, because there are no noise-sensitive receptors located along these two segments, the impact would not be significant.
TABLE 17
NIGHTTIME HOUR TRAFFIC NOISE INCREASES ALONG ROADS IN THE PROJECT VICINITY Roadway Segment Background
Applicable
Increase
Threshold
(dB)
Background
plus Full
Buildout
of Project
dBA
Difference
Significant
Increase?
Weekday Peak-Hour Noise Levels
Lafayette Street North of Great America Way 64.7 3 65.0 0.3 No Lafayette Street between Great America Way and Future
Driveway to Parcel 1
65.4 3 67.9 2.5 No
Lafayette Street South of Future Driveway to Parcel 1 65.4 3 67.3 1.9 No Tasman Drive west of Great America Parkway 65.1 3 67.2 2.1 No Tasman Drive between Great America Parkway and Lick Mill Boulevard
66.9 3 68.9 2.0 No
Tasman Drive east of Lick Mill Boulevard 67.2 3 68.8 1.6 No Lick Mill Boulevard south of Tasman Drive 62.3 3 64.1 1.8 No Great America Parkway North of Great America Way 69.3 3 72.4 3.1 NAa Great America Parkway between Great America Way and
Mountain View-Alviso Road
69.5 5 72.4 2.9 No
Great America Parkway between Mountain View-Alviso Road and Tasman Drive
68.6 3 71.6 3.0 NA
a
Great America Parkway south of Tasman Drive 69.7 3 72.4 2.7 No SR 237 West of Great America Parkway 76.7 3 77.2 0.5 No SR 237 East of Great America Parkway 75.4 3 76.0 0.6 No NOTES: dB = decibels; dBA = A-weighted decibels; NA = not applicable a. There are no existing noise-sensitive land uses along these roadway segments; thus, the impact would be less than significant.
SOURCES: Traffic data compiled by ARUP in 2024, and modeling performed by Environmental Science Associates in 2024.
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Impact NOI-2/C-NOI-2: Would the Scheme C Project expose people to or generate excessive groundborne vibration or groundborne noise levels during construction or operation? / Would the Scheme C Project, when considered with other cumulative development, expose people to or generate excessive groundborne vibration or groundborne noise levels during construction or operation? Approved Project
Under the Approved Project, Parcel 1 was to be developed with 1.2 million square feet (sf) of office space while parcel 2 was to be developed with 2.16 million sf of office space. The 2016 EIR found that construction vibration impacts on off-site receptors would be less than significant. With respect to on-site receptors, the 2016 EIR found that pile driving could result in ground vibration that disturbs new residences, and this impact was identified as significant. Mitigation Measure NOI-2.1 was identified to restrict pile driving within 175 feet of receptors to be conducted prior to occupancy in order to reduce the impact to less than significant with mitigation.
Additionally, the 2016 EIR identified a potential significant impact with respect to vibration from existing UPRR rail operations potentially affecting on-site residential uses of Parcel 5. Mitigation Measure NOI-2.2 was identified to prepare and implement a Vibration Control Plan to reduce vibration from the UPRR railroad operations for proposed sensitive land uses in order to reduce the impact to less than significant with mitigation.
Scheme C
As discussed above with respect to construction noise, it is assumed that the construction footprints between the Approved Project and Scheme C would not change substantially and that, because the increase in density in Parcel 4 would likely be accommodated by building height, construction noise and vibration impacts would be similar to those indicated in the 2016 EIR with the changes primarily resulting in an increased duration of the overall construction timeline. An increased duration of less than significant vibration levels would not result in a new impact. Therefore, construction-related vibration impacts associated with Scheme C would also be less than significant with mitigation and additional quantitative analysis of construction-related vibration is not warranted.
With respect to operational vibration impacts of existing rail activity on portions of Parcel 5 that were identified in the 2016 EIR, Scheme C would not result in any changes in the development scheme for Parcel 5. Therefore, the operational vibration impact Scheme C would also be less than significant with Mitigation Measure NOI-2.2, similar to the Approved Project. It is further noted that the potential effects of the environment on the project are no longer legally required to be analyzed or mitigated under CEQA, except where the project impacts exacerbate the existing conditions.
Impact NOI-5: Would Scheme C be located within an airport land use plan area or, where such a plan has not been adopted, within 2 miles of a public airport or public use airport and would Scheme C expose people residing or working in the Project area to excessive noise levels?
As discussed above, a portion of the project site was within the 65 CNEL noise contour of San José Mineta International Airport (SJC) as designated in the 2011 CLUP. The FAA considers all land uses to be compatible when aircraft noise effects are less than 65 dB CNEL. (SCALUC, 2011). Although a new
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CLUP was approved in 2024 with updated noise contours, this analysis applies the contours of the 2011 CLUP in the analysis of airport noise, consistent with the 2016 EIR. However, an additional, non-CEQA, assessment is provided relative to the updated 2024 CLUP.
Approved Project
Under the Approved Project, proposed residential uses located within the southwestern portions of Parcels 4 and 5 were identified as within the 65 CNEL contour from operations of SJC, resulting in a significant impact. Mitigation Measure NOI-1.3 was identified to reduce interior noise levels for residential uses to 45 dB CNEL or less. However, because the Approved Project would include outdoor residential areas located within the airport’s 65 dB CNEL contour, it would result in a land use that is not compatible with the airports Comprehensive Land Use Plan and the impact was found to be significant and unavoidable.
Scheme C
Scheme C would increase the density of the approved uses in the City Center Mixed Use & Northwest Office (Parcel 4). Therefore, while there may be more residences with outdoor living space within the 65 CNEL contour under Scheme C, it would have the same significant and unavoidable aircraft noise impact described in the 2016 EIR, as Mitigation Measure NOI-1.3 would not reduce airport noise in outdoor areas. This impact would not be exacerbated building height to accommodate additional residential uses as the noise contours that are the basis for assessment in the CLUP are not affected by elevation.
It should be additionally noted that the County Airport Land Use Commission has adopted an update to its CLUP in March 2024 and this updated CLUP contains updated Noise Contours for airport operations.
Based on the 2024 contours contained in Figure 5 of the 2024 CLUP, the City Center and Parcels 1 and 2 are no longer within the 65 CNEL noise contour.
Impact NOI-1d (Non-CEQA noise impacts of the environment on the project): Operational Noise Impacts on On-Site Land Uses.
Development of the Approved Project could expose future occupants of the project site to existing sources of noise. However, CEQA does not require that potential effects of the environment on the project be analyzed or mitigated. Nevertheless, an analysis of existing noise effects on the project is included to provide information to the public and decision-makers, to comply with General Plan policies, and to be consistent with the analysis presented in the 2016 EIR.
Approved Project
Under the Approved Project, Parcel 1 was to be developed with 1.2 million square feet (sf) of office space while parcel 2 was to be developed with 2.16 million sf of office space. The 2016 EIR found that events at Levi’s Stadium, which is adjacent to the project site, are a considerable noise source in the Project area including portions of Parcels 4 and 5, which includes areas where new residential, commercial, and hotel land uses would be constructed. The 2016 EIR cited the 2009 49ers Stadium Project Environmental Impact Report which concluded that noise during sporting events at the stadium would exceed background levels by 19 to 24 dBA. Thus, residents and hotel occupants at the project site would be exposed to elevated noise levels during periods when the stadium hosts major events, resulting in a significant impact. Acoustical treatments included in Mitigation Measure NOI-1.3 (see discussion above) would not
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mitigate stadium noise at the outdoor residential recreational areas and operational noise impacts during stadium events would remain significant and unavoidable even with mitigation.
Scheme C
Scheme C would increase the density of the approved uses in the City Center Mixed Use & Northwest Office (Parcel 4). Therefore, while there may be more residences with outdoor living space within the affected by event noise from Levi’s stadium under Scheme C, it would have the same significant and unavoidable event noise impact described in the 2016 EIR, as Mitigation Measure NOI-1.3 would not reduce event noise in outdoor areas.
It is noted that noise monitoring data presented in Table 1 shows that the existing noise environment of Parcels 1 and 2 are 61 to 62 Ldn, which would be compatible with the City’s General Plan exterior noise standards for industrial uses shown in Table 8.
Cumulative Impacts
Impact C-NOI-1 Would operation of Scheme C expose persons to or generate noise levels, in combination with cumulative development, in excess of standards established in a local general plan or noise ordinance or applicable standards of other agencies? Approved Project
Under the Approved Project, Parcel 1 was to be developed with 1.2 million square feet (sf) of office space while Parcel 2 was to be developed with 2.16 million sf of office space. The 2016 EIR found four roadway segments where significant cumulative noise impacts are predicted to occur and where the Approved Project’s contribution to those impacts is cumulatively considerable. Implementation of Mitigation Measure NOI-1.2 was identified to reduce this impact. However, development of soundwalls along the other three roadway segments was found to be infeasible due to inconsistency with General Plan policies and the limitation of soundwalls to reduce noise levels for occupants of buildings above the ground floor.
Hence, the impact was disclosed as significant and unavoidable.
Scheme C
As stated above, for construction noise, the same equipment would be used and the same distance to receptors analyzed in the 2016 EIR would occur. While there could be a greater duration of construction activity, this would not affect the magnitude of the noise levels experienced at nearby receptors and would not result in a further temporary or periodic increase in ambient noise levels. Therefore, the cumulative impacts from construction would be the same as identified in the 2016 EIR. While there is existing cumulative construction occurring along Calle del Mundo that was not envisioned in the 2016 EIR, this construction will be complete by the time construction under Scheme C commences. Therefore, there would be no new cumulative construction noise impacts.
Cumulative noise impacts from operations would occur if new sources were to be developed within 800 feet of project elements. While there will be new residential land uses becoming occupied along Calle del Mundo that were not envisioned in the 2016 EIR, residential uses are generally not considered to be a noise generating use.
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Operational noise impacts of Scheme C would result primarily from increased traffic on the local roadway network. Cumulative (year 2035) plus project traffic data were used to estimate cumulative operational noise increases. The 2035 traffic data inherently include City growth projections.16 The significance of cumulative impacts related to traffic noise levels is determined using a two-step process.
If a cumulative impact is identified, the second step is to evaluate whether the contribution of the project to roadside noise levels would be cumulatively considerable. The roadway segments analyzed and the noise increases resulting from modeling are shown in Table 18 for 203540 Cumulative plus project weekday with full buildout of the Scheme C project’s mixed uses.
As shown in Table 18, although cumulative traffic noise impacts would occur along 11 of the 13 roadways analyzed, the traffic noise associated with Scheme C would only represent a cumulatively considerable contribution to these cumulative impacts (i.e., there would be an increase of 1.0 dBA or more over the cumulative without project scenario) along six of the roadways. Further, sensitive receptors are located along only two of the six roadway segments, for which a significant cumulative contribution is identified.
While there would be a cumulatively considerable contribution to the cumulative traffic noise impacts along two segments of Tasman Drive, the 2016 EIR identified significant and unavoidable cumulative traffic impacts along four roadway segments (see Table 19). Therefore, Scheme C would result in a fewer number of impacted roadways than identified in the 2016 EIR and would not result in new or more severe traffic noise impacts.
16 See the 2024 Related Santa Clara Traffic Analysis Memo prepared by Arup for the Project Applicant and peer reviewed by Hexagon for the City of Santa Clara. Per the 2024 Related Santa Clara Traffic Analysis Memo, cumulative traffic volumes are based on the latest available County of Santa Clara Travel Demand Model outputs considering current data for development projects and adjusted for 2018/19 traffic counts. 6 References
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6 References
ARUP, email communication from Joerg Tonndorf to Environmental Science Associates containing spreadsheet, July 5, 2024.
California Department of Transportation (Caltrans), Technical Noise Supplement, November 2009.
California Department of Transportation (Caltrans), Technical Noise Supplement to the Traffic Noise Analysis Protocol, September 2013.
California Department of Transportation (Caltrans), Transportation and Construction Vibration Guidance Manual, April 2020.
Cummins Power Generation, Deisel Generator Set K19 Series 600/625 kVA Specification Sheet, 2018.
Environmental Science Associates, Fresh and Easy Distribution Truck Noise Study, December 3, 2008.
Federal Highway Administration (FHWA), Roadway Construction Noise Model User Guide, 2006.
Federal Interagency Committee on Noise, Federal Agency Review of Selected Airport Noise Analysis Issues, August 1992.
Federal Transit Administration (FTA), Transit Noise and Vibration Impact Assessment, 2018.
Governor’s Office of Planning and Research (OPR), State of California General Plan Guidelines, 2017.
Illingworth and Rodkin, 550 Piercy Road Noise and Vibration Assessment, San José, California, May 2023.
Santa Clara County Airport Land Use Commission (SCALUC), Comprehensive Land Use Plan Santa Clara County, May 2011.
Trane, Engineering Bulletin, Sound Data and Application Guide for New and Quieter Air-Cooled Series R Chiller, 2002.
U.S. Environmental Protection Agency (EPA), Information on Levels of Environmental Noise Requisite to Protect Public Health and Welfare with an Adequate Margin of Safety, March 1974. Available at:
https://nepis.epa.gov/Exe/ZyPDF.cgi/2000L3LN.PDF?Dockey=2000L3LN.PDF.
World Health Organization, Guidelines for Community Noise, Geneva, Switzerland, 1999. Available at:
http://www.euro.who.int/en/health-topics/environment-and-health/noise/environmental-noise- guidelines-for-the-european-region.
6 References
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TABLE 18
MODELED TRAFFIC NOISE LEVELS YEAR 2035 WITH WEEKDAY P.M. FULL BUILDOUT OF SCHEME C PROJECT MIXED USES Roadway Segment Background
Applicable
Increase
Threshold
(dB)
2035 plus
Full Buildout
of Scheme C Project
Mixed Uses
dBA Difference 2035
plus Full Buildout
of Scheme C Project Mixed
Uses from Background
Significant
Cumulative
Increase?
2035
No
Project
dBA Difference 2035
plus Full Buildout of
Scheme C Project Mixed Uses
from 2035 No Project
Cumulatively
Considerable
Scheme C Project
Increaseg?
Weekday Noise Levels
Lafayette Street North of Great America Way 65.9 3 69.2 3.3 Yes 69.0 0.2 No Lafayette Street between Great America Way and Future Driveway to Parcel 1 67.5 3 70.7 3.2 Yes 69.9 0.8 No Lafayette Street South of Future Driveway to Parcel 1 67.5 3 70.6 3.1 Yes 70.0 0.6 No Tasman Drive west of Great America Parkway 67.6 3 71.6 4.0 Yes 70.1 1.5 Yes Tasman Drive between Great America Parkway and Lick Mill Boulevard 68.7 3 72.0 4.0 Yes 70.6 1.4 Yes Tasman Drive east of Lick Mill Boulevard 69.1 3 72.2 3.2 Yes 71.3 0.9 No Lick Mill Boulevard south of Tasman Drive 64.4 3 67.6 3.2 Yes 66.6 1.0 No Great America Parkway North of Great America Way 71.3 3 74.2 2.9 No 72.2 2.0 NAa Great America Parkway between Great America Way and Mountain View-Alviso Road 70.8 3 74.7 3.9 Yes 73.2 1.5 NAa Great America Parkway between Mountain View-Alviso Road and Tasman Drive 69.8 3 73.1 3.3 Yes 71.8 1.3 NAa Great America Parkway south of Tasman Drive 71.3 3 73.5 2.2 No 72.2 1.3 NAa SR 237 West of Great America Parkway 77.9 3 78.4 0.5 No 78.0 0.4 N/A SR 237 East of Great America Parkway 77.0 3 77.6 0.6 No 77.1 0.5 N/A NOTES:
dB = decibels; dBA = A-weighted decibels; N/A = The cumulative contribution test for the roadway is not applicable because there is no cumulative impact along this roadway. a There are no noise-sensitive land uses along these roadway segments; thus, the impact would be less than significant.
Source: Traffic data compiled by ARUP in 2024; Modeling conducted by Environmental Science Associates in 2024.
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TABLE 19
CUMULATIVE YEAR 2040 AND CUMULATIVE YEAR 2040 PLUS‐APPROVED PROJECT NOISE LEVELS AT ACTUAL DISTANCE TO OFF‐SITE RECEPTORS UNDER THE 2016 EIR Roadway Segment
Approximate
Distance to Nearest
Receptor (feet)
Receptor Land Use
Type
Existing Ldn at
Nearest Receptor
Cumulative Ldn at
Nearest Receptor
Cumulative plus-
Project Ldn at
Nearest Receptor
Cumulative
Increase
(Difference
between Existing
and Cumulative
plus Project)
Significant
Cumulative
Impact?
Project
Contribution to
Noise Level
Cumulatively
Considerable
Contribution?
Tasman Drive Boulevard to Calle Del Sol 105 R 70.0 71.5 72.9 2.9 No 1.3 NA Agnew Road – De La Cruz Expressway to 50 R 65.2 70.6 71.6 6.4 Yes 1.0 Yes Great America SR‐237 to Yerba Buena America Way 200 O 70.9 73.8 74.5 3.6 Yes .7 No Great America Yerba Buena America Way to Old Mountain Road 80 O 74.6 74.1 75.8 1.2 No 1.7 NA SR‐237 to Great America Way No Existing NA NA NA NA NA NA NA NA Lafayette Street Great America Way to future driveway (south) 340 O 72.3 72.5 72.6 0.2 No .1 NA Lafayette Street Calle Del Mundo to Tasman Drive 50 O 66.0 71.8 74.9 8.9 Yes 3.0 Yes Lafayette Street Tasman Drive to Hogan Drive 55 R 71.0 72.3 75.0 4.0 Yes 2.7 Yes Lafayette Street Hogan Drive to Hope Drive 50 R 71.3 73.0 75.4 4.2 Yes 2.4 Yes Lafayette Street Hope Drive to Agnew Road 60 R 72.1 72.7 74.8 2.6 No 2.1 NA Lafayette Street Agnew Road to Palm Drive 190 R 67.0 68.0 69.6 2.6 No 1.6 NA Notes: Bold = significant impact, R = residential, O = office, NA = not applicable Traffic noise was modeled using AM or PM Peak‐Hour traffic volumes (whichever was higher); in this case, this was the PM Peak Hour, with the exception of the Great American Parkway from Yerba Buena Way to Old Mountain Road, which had much higher AM Peak‐Hour with‐Project traffic volumes.
Modeled 1‐hour Leq values were conservatively converted into Ldn values by adding 2 dBA to each Leq result (based on trends in the 24‐hour noise measurements).
Appendix A
Noise Monitoring Data, Stationary
Source Calculations and Traffic
Noise Level Calculations
Appendix NOI
Noise Appendix
ESA / D201901172.02 Related Santa Clara Noise Study
May 2024
Traffic Noise Model
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2020 Baseline AM
Source of Traffic Volumes: ARUP; and Caltrans for SR 237 Auto MT HT Auto MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 759 20 10 65.6 65.9 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 1,104 29 14 67.2 67.5 Lafayette Street South of Future Driveway to Parcel 1 Hard 50 40 40 40 1,105 29 14 67.2 67.5 Tasman Drive west of Great America Parkway Hard 50 40 40 40 1,144 27 14 67.3 67.6 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 1,597 25 13 68.4 68.7 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 1,700 31 15 68.8 69.1 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 841 15 8 64.1 64.4 Great America Parkway North of Great America Way Hard 50 40 40 40 1,644 143 70 71.0 71.3 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 1,481 129 64 70.5 70.8 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 1,273 94 46 69.5 69.8 Great America Parkway south of Tasman Drive Hard 50 40 40 40 1,793 132 65 71.0 71.3 SR 237 West of Great America Parkway Hard 160 65 65 65 8,352 87 261 77.6 77.9 SR 237 East of Great America Parkway Hard 160 65 65 65 6,912 72 216 76.7 77.0 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Roadway Segment Ground
Type
Distance from
Roadway to
Receiver (feet)
Speed (mph) Peak Hour Volume Peak Hour
Noise Level
(Leq(h) dBA)
Noise Level
dBA CNEL
Traffic Noise Baseline AM 1 of 1 5/29/2024
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2020 Baseline AM + Project
Source of Traffic Volumes: ARUP
Auto MT HT Auto MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 855 20 12 66.1 66.4 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 1,410 29 34 68.7 69.0 Lafayette Street South of Future Driveway to Parcel 1 Hard 55 40 40 40 1,233 29 24 67.5 67.8 Tasman Drive west of Great America Parkway Hard 50 40 40 40 1,884 27 14 69.0 69.3 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 2,917 25 13 70.6 70.9 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 2,562 31 15 70.2 70.5 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 1,299 15 8 65.6 65.9 Great America Parkway North of Great America Way Hard 50 40 40 40 3,880 143 86 73.3 73.6 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 3,513 129 66 72.7 73.0 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 2,535 94 48 71.3 71.6 Great America Parkway south of Tasman Drive Hard 50 40 40 40 3,736 132 67 72.9 73.2 SR 237 West of Great America Parkway Hard 160 65 65 65 9,550 87 269 78.1 78.4 SR 237 East of Great America Parkway Hard 160 65 65 65 7,950 72 224 77.3 77.6 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Roadway Segment Ground
Type
Distance from
Roadway to
Receiver (feet)
Speed (mph) Peak Hour Volume Peak Hour
Noise Level
(Leq(h) dBA)
Noise Level
dBA CNEL
Traffic Noise Baseline AM + Project 1 of 1 5/29/2024
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2020 Baseline Nighttime
Source of Traffic Volumes: ARUP
Auto MT HT Auto MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 435 15 22 64.7 65.0 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 664 23 11 65.4 65.7 Lafayette Street South of Future Driveway to Parcel 1 Hard 50 40 40 40 682 23 11 65.4 65.7 Tasman Drive west of Great America Parkway Hard 50 40 40 40 639 20 10 65.1 65.4 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 1,081 23 11 66.9 67.2 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 1,123 26 13 67.2 67.5 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 521 13 6 62.3 62.6 Great America Parkway North of Great America Way Hard 50 40 40 40 951 110 54 69.3 69.6 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 988 115 56 69.5 69.8 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 898 87 43 68.6 68.9 Great America Parkway south of Tasman Drive Hard 50 40 40 40 1,160 113 55 69.7 70.0 SR 237 West of Great America Parkway Hard 160 65 65 65 6,780 71 212 76.7 77.0 SR 237 East of Great America Parkway Hard 160 65 65 65 5,099 53 159 75.4 75.7 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Peak Hour
Noise Level
(Leq(h) dBA)
Noise Level
dBA CNELRoadway Segment Ground
Type
Distance from
Roadway to
Receiver (feet)
Speed (mph) Peak Hour Volume
Traffic Noise Baseline Nighttime 1 of 1 5/29/2024
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2020 Baseline Nighttime + Project
Source of Traffic Volumes: ARUP
Auto MT HT Auto MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 461 15 24 65.0 65.3 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 706 23 64 67.9 68.2 Lafayette Street South of Future Driveway to Parcel 1 Hard 50 40 40 40 719 23 46 67.3 67.6 Tasman Drive west of Great America Parkway Hard 50 40 40 40 921 20 32 67.2 67.5 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 1,517 23 36 68.9 69.2 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 1,405 26 39 68.8 69.1 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 675 13 19 64.1 64.4 Great America Parkway North of Great America Way Hard 50 40 40 40 1,643 110 184 72.4 72.7 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 1,664 115 179 72.4 72.7 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 1,646 87 138 71.6 71.9 Great America Parkway south of Tasman Drive Hard 50 40 40 40 1,750 113 172 72.4 72.7 SR 237 West of Great America Parkway Hard 160 65 65 65 7,114 71 222 76.9 77.2 SR 237 East of Great America Parkway Hard 160 65 65 65 5,457 53 169 75.7 76.0 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Peak Hour
Noise Level
(Leq(h) dBA)
Noise Level
dBA CNELRoadway Segment Ground
Type
Distance from
Roadway to
Receiver (feet)
Speed (mph) Peak Hour Volume
Traffic Noise Baseline Nighttime + Project 1 of 1 5/29/2024
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2040 Cumulative AM
Source of Traffic Volumes: ARUP
Auto MT HT Au to MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 1,495 43 21 68.7 69.0 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 1,880 54 26 69.6 69.9 Lafayette Street South of Future Driveway to Parcel 1 Hard 50 40 40 40 1,887 54 26 69.7 70.0 Tasman Drive west of Great America Parkway Hard 50 40 40 40 2,047 50 25 69.8 70.1 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 2,360 48 24 70.3 70.6 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 2,901 51 25 71.0 71.3 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 1,388 25 12 66.3 66.6 Great America Parkway North of Great America Way Hard 50 40 40 40 2,288 159 78 71.9 72.2 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 2,904 201 99 72.9 73.2 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 2,468 115 57 71.5 71.8 Great America Parkway south of Tasman Drive Hard 50 40 40 40 2,667 125 61 71.9 72.2 SR 237 West of Great America Parkway Hard 160 65 65 65 8,519 89 266 77.7 78.0 SR 237 East of Great America Parkway Hard 160 65 65 65 7,050 73 220 76.8 77.1 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The
peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For
soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Roadway Segment Ground
Type
Distance from
Roadway to
Rec
eiver (feet)
Speed (mph) Pe ak Hour Volume Peak Hour
Noise Level
(L
eq(h) dBA)
Noise Level
dBA CNEL
Traffic Noise Cumulative AM 071324 1 of 1 7/16/2024
TRAFFIC NOISE ANALYSIS TOOL
Project Name: Related Santa Clara
Analysis Scenario: 2040 Cumulative AM + Project
Source of Traffic Volumes: ARUP
Auto MT HT Au to MT HT
Lafayette Street North of Great America Way Hard 50 40 40 40 1,597 44 22 68.9 69.2 Lafayette Street between Great America Way and Future Driveway to Parcel 1 Hard 50 40 40 40 2,194 67 33 70.4 70.7 Lafayette Street South of Future Driveway to Parcel 1 Hard 50 40 40 40 2,200 64 31 70.3 70.6 Tasman Drive west of Great America Parkway Hard 50 40 40 40 3,127 50 25 71.3 71.6 Tasman Drive between Great America Parkway and Lick Mill Boulevard Hard 50 40 40 40 3,527 48 24 71.7 72.0 Tasman Drive east of Lick Mill Boulevard Hard 50 40 40 40 3,687 51 25 71.9 72.2 Lick Mill Boulevard south of Tasman Drive Hard 50 35 35 35 1,863 25 12 67.3 67.6 Great America Parkway North of Great America Way Hard 50 40 40 40 4,604 170 83 73.9 74.2 Great America Parkway between Great America Way and Mountain View-Alviso Road Hard 50 40 40 40 5,008 202 100 74.4 74.7 Great America Parkway between Mountain View-Alviso Road and Tasman Drive Hard 50 40 40 40 3,851 117 57 72.8 73.1 Great America Parkway south of Tasman Drive Hard 50 40 40 40 4,260 126 62 73.2 73.5 SR 237 West of Great America Parkway Hard 160 65 65 65 9,760 89 274 78.1 78.4 SR 237 East of Great America Parkway Hard 160 65 65 65 8,125 73 228 77.3 77.6 Model Notes:
The calculation is based on the methodology described in FHWA Traffic Noise Model Technical Manual (1998).
The
peak hour noise level at 50 feet was validated with the results from FHWA Traffic Noise Model Version 2.5.
Accuracy of the calculation is within ±0.1 dB when comparing to TNM results.
Noise propagation greater than 50 feet is based on the following assumptions:
For hard ground, the propagation rate is 3 dB per doubling the distance.
For
soft ground, the propagation rate is 4.5 dB per doubling the distance.
Vehicles are assumed to be on a long straight roadway with cruise speed.
Roadway grade is less than 1.5%.
CNEL levels were obtained based on Figure 2-19, on page 2-58 Caltran's TeNS 2013.
Roadway Segment Ground
Type
Distance from
Roadway to
Rec
eiver (feet)
Speed (mph) Pe ak Hour Volume Peak Hour
Noise Level
(L
eq(h) dBA)
Noise Level
dBA CNEL
Traffic Noise Cumulative AM + Project 071324 1 of 1 7/16/2024 Appendix NOI
Noise Appendix
ESA / D201901172.02 Related Santa Clara Noise Study
May 2024
Stationary Source Noise
Modeling
HVAC Noise Analysis
Determination of noise at nearest receptor
Noise Specification: 69 dBA at 20 feet Source: Illingworth and Rodkin, 2023 Assume 5 industrial HVAC Packages operated simula 76 dBA at 20 feet Ni = No - 20(log Di/Do)
where:
Ni= attenuated noise level of interest
No= reference noise level
Di= distance to receptor
Do= reference distance
Receptor 2: Shorewood Lane Residences
Receptor 1: Calle del Mundo Residences
Source : HVAC
Source : HVAC
No= 76 dBA
No= 76 dBA Di= 750 ft
Di= 500 ft Do= 20 ft
Do= 20 ft Ni= 44.52 dBA
Ni= 48.04 dBA
Generator Noise Analysis
Determination of noise at nearest receptor
23 feet Source: Cummins 2018
83 dBA at 23 feet
Noise Specification: 75 dBA at
Assume 6 generators tested simultaneously
Ni = No - 20(log Di/Do)
where:
Ni= attenuated noise level of interest
No= reference noise level
Di= distance to receptor
Do= reference distance
Receptor 2: Shorewood Lane Residences
Receptor 1: Calle del Mundo Residences
Source : Generator
Source : Generator
No= 83 dBA
No= 83 dBA Di= 750 ft
Di= 500 ft Do= 3 ft
Do= 3 ft Ni= 35.04 dBA
Ni= 38.56 dBA
Truck Manuevering Analysis
Determination of noise at nearest receptor
Ni = No - 20(log Di/Do)
where:
Ni= attenuated noise level of interest
No= reference noise level
Di= distance to receptor
Do= reference distance
Receptor 2: Shorewood Lane Residences
Receptor 1: Calle del Mundo Residences
Source : Truck Maneuvering into Loading Area with Operating TRU Source : Truck Maneuvering into Loading Area with Operating TRU No= 65.9 dBA
No= 65.9 dBA Di= 750 ft
Di= 500 ft Do= 50 ft
Do= 50 ft Ni= 42.38 dBA
Ni= 45.90 dBA
Source : TRU On with Engine at Idle
Source : TRU On with Engine at Idle
No= 65.5 dBA
No= 65.5 dBA Di= 750 ft
Di= 500 ft Do= 50 ft
Do= 50 ft Ni= 41.98 dBA
Ni= 45.50 dBA
Source : TRU On with Engine Off
Source : TRU On with Engine Off
No= 61.7 dBA
No= 61.7 dBA Di= 750 ft
Di= 500 ft Do= 50 ft
Do= 50 ft Ni= 38.18 dBA
Ni= 41.70 dBA
Maximum noise level = 42.38
Maximum noise level = 45.90
Attenuation from structure = 16 dBA (as calculated by HUDs Barrier Performance Module) Resultant noise level = 26.38
Resultant noise level = 29.90
Multiple operations (5) = 33
Multiple operations (5) = 36.9
Calculation of Back-up Alarm Noise Levels from Industrial Loading Areas Site Location: Parcel 2 Northernmost building Related Santa Clara Distance from loading dock to property line of site = 800 feet per site plan Distance from property line of site to property line of nearest residence = 20 feet per Google Earth Total distance between source and receiver = 820 feet
Published noise level at source: 87 -112 dBA Source: OEM 2007 Average documented noise level = 99.5
Working assumed Noise level : 105 dBA Reasoning: source data wide and old. Per article improvements made by manufacturers over time Select upper end but not top end
Attenuation of noise with distance
Ni = No - 20(log Di/Do) (Caltrans, 2013)
where:
Ni= attenuated noise level of interest
No= reference noise level
Di= distance to receptor
Do= reference distance
No= 105 dBA
Di= 820 ft
Do= 4 ft
Ni= 59 dBA
Attenuation by 60-foot structure = 16 dBA (As calculated using HUD's Barrier Performance Module) Realized noise level at receptor w/ shielding = 43 dBA
Noise Source 43 43 43 43 43
Remove LOG 18901.3262 18901.33 18901.33 18901.33 18901.33 Adding Noise Sources 49.8
(5 Trucks)
Calculation of Back-up Alarm Noise Levels from Industrial Loading Areas Site Location: Parcel 2 Northernmost building Related Santa Clara Distance from loading dock to property line of site = 800 feet per site plan Distance from property line of site to property line of nearest residence = 20 feet per Google Earth Total distance between source and receiver = 820 feet
Published noise level at source: 87 -112 dBA Source: OEM 2007 Average documented noise level = 99.5
Working assumed Noise level : 105 dBA Reasoning: source data wide and old. Per article improvements made by manufacturers over time Select upper end but not top end
Attenuation of noise with distance
Ni = No - 20(log Di/Do) (Caltrans, 2013)
where:
Ni= attenuated noise level of interest
No= reference noise level
Di= distance to receptor
Do= reference distance
No= 105 dBA
Di= 820 ft
Do= 4 ft
Ni= 59 dBA
Attenuation by 60-foot structure = 16 dBA (As calculated using HUD's Barrier Performance Module) Realized noise level at receptor w/ shielding = 43 dBA
Noise Source 43 43 43 43 43
Remove LOG 18901.3262 18901.33 18901.33 18901.33 18901.33 Adding Noise Sources 49.8
(5 Trucks)
Home (/)>Programs (/programs/)>Environmental Review (/programs/environmental- review/)>BPM Calculator
Barrier Performance Module
This module provides to the user a measure on the barrier's e ectiveness on noise reduction. A list of the input/output variables and their de nitions, as well as illustrations of di erent scenarios are provided.
Calculator
View Day/Night Noise Level Calculator (/programs/environmental-review/dnl-calculator/) View Descriptions of the Input/Output variables.
Note:
Tool tips, containing eld speci c information, have been added in this tool and may be accessed by hovering over the Input and Output variables with the mouse.
WARNING: If there is direct line-of-sight between the Source and the Observer, the module will report erroneous attenuation. “Direct line-of-sight” means if the 5’ tall Observer can see the noise Source (cars, trucks, trains, etc.) over the Barrier (wall, hill/excavation, building, etc.), the current version of Barrier Performance Module will not accurately calculate the attenuation provided. In this instance, there is unlikely to be any appreciable attenuation.
Note: Barrier height must block the line of sight
Input Data
H
60 R 20
S 12 D 500
O77 α 180
Calculate Output
Output Data
h 45 R 26
D497 FS159971
1 1
7/11/24, 5:20 PM BPM Calculator - HUD Exchange
https://www.hudexchange.info/environmental-review/bpm-calculator/ 1/6 Home (/)>Programs (/programs/)>Environmental Review (/programs/environmental- review/)>BPM Calculator
Barrier Performance Module
This module provides to the user a measure on the barrier's e ectiveness on noise reduction. A list of the input/output variables and their de nitions, as well as illustrations of di erent scenarios are provided.
Calculator
View Day/Night Noise Level Calculator (/programs/environmental-review/dnl-calculator/) View Descriptions of the Input/Output variables.
Note:
Tool tips, containing eld speci c information, have been added in this tool and may be accessed by hovering over the Input and Output variables with the mouse.
WARNING: If there is direct line-of-sight between the Source and the Observer, the module will report erroneous attenuation. “Direct line-of-sight” means if the 5’ tall Observer can see the noise Source (cars, trucks, trains, etc.) over the Barrier (wall, hill/excavation, building, etc.), the current version of Barrier Performance Module will not accurately calculate the attenuation provided. In this instance, there is unlikely to be any appreciable attenuation.
Note: Barrier height must block the line of sight
Input Data
H
60 R 200
S 12 D 800
O77 α 180
Calculate Output
Output Data
h 35 R 203
D799 FS131038
1 1
7/9/24, 10:19 AM BPM Calculator - HUD Exchange
https://www.hudexchange.info/environmental-review/bpm-calculator/ 1/6 Appendix NOI
Noise Appendix
ESA / D201901172.02 Related Santa Clara Noise Study
May 2024
Noise Monitoring
Calculated Ldn from Long-Term Noise Monitoring Data
Meter 0004435
4/3/2024
Wednesday 10 dBA 5 dBA
TIME dBA Numbers... More
Numbers...
Midnight 0 / 24 47.3 53558 535576 169364 Leq Nighttime 10:00 p.m.-7:00 a.m. (not penalized) am 1:00 100 48.1 64139 641385 202824 52 dBA
2:00 200 50.4 109531 1095307 346367
3:00 300 48.4 69104 691041 218526 Leq Daytime 7:00 am-10:00 p.m. 4:00 400 49.3 84615 846149 267576 59 dBA
5:00 500 50.5 111259 1112592 351833
6:00 600 56.9 486370 4863702 1538038 Leq 24-Hour
7:00 700 58.9 772129 7721292 2441687 57 dBA
8:00 800 59.2 825433 8254333 2610249
9:00 900 58.8 761404 7614037 2407770 Ldn: 10 dBA penalty for noise between 10:00 p.m. and 7:00 a.m. 10:00 1000 58.6 729169 7291687 2305834 60 dBA
11:00 1100 57.0 500781 5007812 1583609
12:00 1200 58.6 723046 7230461 2286473 CNEL: 5 dBA penalty for noise between 7:00p.m. and 10:00 p.m., pm 1:00 1300 58.1 651998 6519976 2061797 60 dBA and 10 dBA penalty for noise between 2:00 1400 59.6 905361 9053615 2863004 10:00 p.m. and 7:00 a.m. 3:00 1500 58.1 651876 6518760 2061413
4:00 1600 57.4 555605 5556048 1756977
5:00 1700 57.9 621096 6210964 1964079 CNEL - Ld 0.4233725 6:00 1800 60.4 1084931 10849307 3430852
7:00 1900 57.6 575578 5755778 1820137
8:00 2000 55.6 360279 3602790 1139302
9:00 2100 52.2 167442 1674422 529499
10:00 2200 48.6 73063 730634 231047
pm 11:00 2300 54.6 289587 2895870 915754
Calculated Ldn from Long-Term Noise Monitoring Data
Meter 0004337
4/3/2024
Wednesday 10 dBA 5 dBA
TIME dBA Numbers... More
Numbers...
Midnight 0 / 24 50.3 108012 1080120 341564 Leq Nighttime 10:00 p.m.-7:00 a.m. (not penalized) am 1:00 100 48.6 72234 722339 228424 54 dBA
2:00 200 47.6 57967 579672 183308
3:00 300 47.0 50318 503182 159120 Leq Daytime 7:00 am-10:00 p.m. 4:00 400 50.1 102128 1021283 322958 61 dBA
5:00 500 50.9 121892 1218919 385456
6:00 600 58.5 709062 7090617 2242250 Leq 24-Hour
7:00 700 57.6 570363 5703625 1803645 58 dBA
8:00 800 55.8 384447 3844475 1215730
9:00 900 57.9 610724 6107240 1931279 Ldn: 10 dBA penalty for noise between 10:00 p.m. and 7:00 a.m. 10:00 1000 57.6 574874 5748744 1817913 62 dBA
11:00 1100 59.1 815609 8156090 2579182
12:00 1200 60.1 1028897 10288972 3253659 CNEL: 5 dBA penalty for noise between 7:00p.m. and 10:00 p.m., pm 1:00 1300 59.9 980490 9804896 3100580 62 dBA and 10 dBA penalty for noise between 2:00 1400 60.5 1117509 11175089 3533874 10:00 p.m. and 7:00 a.m. 3:00 1500 61.0 1264043 12640434 3997256
4:00 1600 60.6 1148159 11481589 3630797
5:00 1700 60.9 1231448 12314478 3894180 CNEL - Ld 0.7961024 6:00 1800 62.2 1667497 16674968 5273088
7:00 1900 61.9 1534239 15342389 4851690
8:00 2000 60.1 1012097 10120967 3200531
9:00 2100 58.7 733542 7335420 2319664
10:00 2200 56.3 430357 4303571 1360909
pm 11:00 2300 56.1 405736 4057364 1283051