INITIAL STUDY
Saratoga Creek Trail Homeridge Park to Central Park
Prepared by the
June 2016
TABLE OF CONTENTS
SECTION 1.0 INTRODUCTION AND PURPOSE ...... 1 SECTION 2.0 PROJECT INFORMATION ...... 2 2.1 PROJECT TITLE ...... 2 2.2 PROJECT LOCATION ...... 2 2.3 LEAD AGENCY CONTACT ...... 2 SECTION 3.0 PROJECT DESCRIPTION ...... 6 SECTION 4.0 SETTING, ENVIRONMENTAL CHECKLIST AND IMPACTS ...... 11 4.1 AREAS OF NO MEASURABLE IMPACT ...... 12 4.2 AESTHETICS ...... 17 4.3 AIR QUALITY ...... 20 4.4 BIOLOGICAL RESOURCES ...... 24 4.5 CULTURAL RESOURCES ...... 37 4.6 GREENHOUSE GAS EMISSIONS ...... 41 4.7 HAZARDS AND HAZARDOUS MATERIALS ...... 44 4.8 HYDROLOGY AND WATER QUALITY ...... 49 4.9 LAND USE ...... 56 4.10 NOISE ...... 58 4.11 RECREATION ...... 62 4.12 MANDATORY FINDINGS OF SIGNIFICANCE ...... 64 SECTION 5.0 REFERENCES ...... 68 SECTION 6.0 AUTHORS AND CONSULTANTS ...... 70
FIGURES
Figure 2.2-1: Regional Map ...... 3 Figure 2.2-2: Vicinity Map ...... 4 Figure 2.2-3: Aerial Map ...... 5 Figure 3.0-1: Trail Alignment and Cross-Sections ...... 7 Figure 4.4-1: Existing Biological Habitats ...... 25 Figure 4.4-2: Mitigation Sites ...... 33
TABLES
Table 4.3-1 Number of Ambient Air Quality Standards Violations and Highest Concentrations (2013-2015)……………………………………..………………………………….. 20 Table 4.4-1 Summary of Biological Habitat Impacts..………………………………………….. 30
Saratoga Creek Trail Initial Study City of Santa Clara i June 2016 TABLE OF CONTENTS
Table 4.4-2 Tree Replacement Ratios………………..………………………………………….. 31 Table 4.7-1 Hazardous Materials Sites Within ¼ Mile of the Project Site..…………………….. 45 Table 4.12-1 Noise and Land Use Compatibility (Ldn & CNEL)……………….……………….. 59
APPENDICES
Appendix A: Biological Resources Report and Wetland Delineation Appendix B: Phase I Environmental Site Assessment Appendix C: Hydraulic Analysis
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SECTION 1.0 INTRODUCTION AND PURPOSE
This Initial Study of environmental impacts has been prepared to conform to the requirements of the California Environmental Quality Act (CEQA), the CEQA Guidelines (California Code of Regulations 15000 et. seq.), and the regulations and policies of the City of Santa Clara. This Initial Study evaluates the environmental impacts which might reasonably be anticipated to result from the proposed Saratoga Creek Trail project.
The City of Santa Clara is the Lead Agency under CEQA and has prepared this Initial Study to address the impacts of implementing the proposed project.
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SECTION 2.0 PROJECT INFORMATION
2.1 PROJECT TITLE
Saratoga Creek Trail – Homeridge Park to Central Park
2.2 PROJECT LOCATION
The project is located on both sides of Saratoga Creek generally between Central Park and Homeridge Park in the City of Santa Clara.
Figure 2.2-1 Regional Map Figure 2.2-2 Vicinity Map Figure 2.2-3 Aerial Photograph and Surrounding Land Uses
2.3 LEAD AGENCY CONTACT
Vincent Luchessi, Senior Civil Engineer City of Santa Clara Public Works Department 1500 Warburton Avenue Santa Clara, CA 95050 408-615-3048 [email protected]
Saratoga Creek Trail Initial Study City of Santa Clara 2 June 2016 880
Fremont 84
Palo Alto Milpitas
101 Mountain View 237 680 280 880 82 Santa Clara
San Jose Project Site
87 Saratoga
9 85 Campbell
101
17 Morgan Hill
0 5 10 Miles
REGIONAL MAP FIGURE 2.2-1
3 Kiely Boulevard Kiely
Kaiser Drive San Tomas Expressway
Via Torino Place Las Palmas Drive Quince Avenue Pepper Tree Lane Hearth Place
Marietta Drive
Layton Street
Pomeroy Avenue Saratoga Creek
Homestead Road Bucher Avenue 4 Homestead Road Salberg Avenue
Kiely Boulevard
Alexander Avenue
Valley Way Ridge Road
Hamilton Lane
Forbes Avenue
Flannery Street
Woodhams Road Project Site 0 500 1000 Feet
VICINITY MAP FIGURE 2.2-2 Project Site
0 100 300 600 Feet
Kiely Boulevard Ki Kiely ely Boulevard ely Aerial Source: Google Earth Pro, May 5, 2016. Photo Date: Jan. 2016
e
n k a e L e Central Park r e C e r a
T
g r to e Via Siena Place a p Siena Place r
p a
e S
P Residential
Marietta Drive
Residential Commercial
Creekside Place Miles Drive Residential Commercial 5
Residential Homestead Road
Homestead RRoadoad
Residential Residential
k e re C a g Kiely BouleBoulevard Howell Avenue to Salem Drive ra a S Barcells Avenue Residential vard
Woodhams Road
AERIAL PHOTOGRAPH AND SURROUNDING LAND USES FIGURE 2.2-3
SECTION 3.0 PROJECT DESCRIPTION
3.1 OVERVIEW
The City of Santa Clara recently prepared a citywide trail network feasibility study. One of the outcomes of this study is that construction of a portion of the planned Saratoga Creek Trail from Kiely Boulevard to Homestead Road was approved to proceed. The objective of the proposed project is to complete the trail between Central Park and Homeridge Park in Santa Clara.
The trail segment addressed in this analysis is part of the County of Santa Clara’s Countywide Trails Master Plan. The proposed trail segment is identified on the County’s Existing and Proposed Regional Trail Connections Map1 and is part of a larger trail alignment referred to as the Saratoga Creek Extension Trail (Map Reference No. O12). This entire alignment, which includes both on- street and off-street segments, extends south from Benton Street to the trail’s confluence with the San Tomas Aquino/Saratoga Trail (No. C5) near Forbes Avenue. When it is fully constructed, the trail would be continuous from Prospect Road in Saratoga in the south to San Francisco Bay in the north, with connections to other trails at various locations.
[Note to Reader: Taken as a whole, Saratoga Creek is a waterway that flows in a southwest to northeast direction. Within the project limits, however, the creek is primarily in a west to east alignment. Therefore, for the purposes of descriptions in this document, directions in relation to the creek will assume the creek is oriented in a west to east direction.]
3.2 DETAILED PROJECT DESCRIPTION
3.2.1 Description of Project Features and Components
The proposed trail would include a combination of asphalt and concrete paving and would be approximately 0.4 miles in length. The description of the specific improvements are broken into the following three segments: 1) Central Park to Kiely Boulevard, 2) Kiely Boulevard to Homestead Road, and 3) Homestead Road to Homeridge Park. Please see Figure 3.0-1 for an overview of the trail project.
Central Park to Kiely Boulevard
An existing segment of the Saratoga Creek Trail, which is also used by SCVWD maintenance vehicles, runs along the north side of Saratoga Creek through Central Park and ends at the sidewalk on the east side of Kiely Boulevard. The project proposes to extend the trail to the west under Kiely Boulevard while retaining the current connection to the sidewalk on the east side of the street. The northern creek bank would be excavated to allow for installation of the 14-foot wide trail. The southern creek bank would be excavated under Kiely Boulevard to provide comparable creek capacity to offset the area taken up by the trail. The trail would be anchored into the creek bank and would be supported on the creek side by a retaining wall. On the south side of the creek, a new ramp
1 https://www.sccgov.org/sites/parks/PlansProjects/Documents/AlignmentStatus_August18_2015.pdf Accessed January 21, 2016.
Saratoga Creek Trail Initial Study City of Santa Clara 6 June 2016 D LV B LY IE KIELYK BLVD
Overcrossing A 7 B A
B Undercrossing UndercrossingUndercrossing HOMESTEADH RD OM E ST EA D RD
SECTION B-B
Source: Mark Thomas & Company TRAIL CROSS-SECTIONS FIGURE 3.0-1 approximately 100 feet in length would be constructed on the east side of Kiely Boulevard for use by SCVWD maintenance vehicles. The southern creek bank would be excavated to allow for installation of the 14-foot wide ramp.
The trail would narrow to 12 feet under Kiely Boulevard. Retaining walls would be installed on both sides of the trail. The northern wall would shore up the creek bank under the roadway and the southern wall would support the trail. There would be approximately 8.5 feet of vertical clearance between the trail and the underside of the Kiely Boulevard bridge.
Kiely Boulevard to Homestead Road
On the west side of Kiely Boulevard, the trail would expand in width to 14 feet and would include a ramp that connects to a new pedestrian bridge over Saratoga Creek parallel to Kiely Boulevard. Some excavation into the north bank of the creek would be needed at this location to accommodate the trail, ramp, and bridge abutments.
The trail would then continue to the west to Homestead Road along the south side of the creek, utilizing the existing maintenance road that is located just beyond the top-of-bank. This would require a minor reconfiguration within an existing, City-owned, parking lot located on the west side of Kiely Boulevard. The trail profile will be set to minimize excavation on the southern side of the creek for this segment of the trail.
At Homestead Road, an existing SCVWD maintenance ramp on the south side of the creek would be removed. The maintenance road located just beyond the top-of-bank on the south side of the creek will be maintained to connect to the sidewalk on the east side of the street. The maintenance road will be graded lower near its junction with the trail leading from Homestead Road undercrossing. On the north side of the creek, a new SCVWD maintenance ramp, approximately 100 feet in length, would be constructed on the north side of Homestead Road. The northern creek bank would be excavated to allow for installation of the 14-foot wide ramp.
Approximately 200 feet east of Homestead Road, the trail would split from the maintenance road and continue to the west under the roadway along the south side of the creek. The trail would narrow to 10 feet under the roadway. Retaining walls would be installed on both sides of the trail. The southern wall would shore up the creek bank under the roadway and the northern wall would support the trail. There would be approximately 8.5 feet of vertical clearance between the trail and the underside of the Homestead Road bridge.
Homestead Road to Homeridge Park
On the south side of Homestead Road, the trail would remain 10 feet in width until it connects to Homeridge Park. At this location, the proposed improvements would include an eight-foot wide pedestrian ramp that would provide a connection between the main trail and the sidewalk on the south side of Homestead Road. The southern creek bank would be excavated to allow for installation of the ramp and trail. A retaining wall would be installed on the south side of the ramp. A second retaining wall would be located between the ramp and the trail due to the difference in elevation. The existing Homestead bridge would be modified to provide connection of the ramp to Homestead
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Road. The sidewalk on the west side of Homestead Road would be widened to serve as a staging area for uses going in and out of the trail.
3.2.2 Description of Construction Methods
The proposed project would be constructed by a contractor and his subcontractors. Additional access to the site would be by staff from the City, SCVWD, and local utility companies. The contractor would utilize a construction staging area that is proposed to be located in the northern portion of Homeridge Park. The staging area would be used for a portable construction trailer as well as for the storage of vehicles, equipment, and materials.
In areas where the trail is being constructed, construction equipment, such as backhoes and hauling trucks, will be used for excavation and grading as well as for import and export of material such as earth, debris, and demolished items. Small vehicles, such as pickup trucks, will also be used for general construction needs. Once the rough grading is complete, paving operations will proceed, consisting of placement of compacted aggregate base material and then placement of the asphalt concrete pavement. Asphalt paving will be done by placement of the asphalt material in two or three stages, each being spread, smoothed and compacted with paving equipment. In most areas, 2-foot shoulders would be provided on each side of the trail, for a total of 14 feet in trail width.
Cut and fill slopes will require clearing of vegetation and debris. These areas will then be grading using construction equipment such as excavators and grading machines.
Retaining walls will be constructed using an excavated footing and concrete formwork, or by the use of soldier piles (i.e., vertical supports for retaining walls) and excavation.
The new pedestrian bridge on the west side of Kiely Boulevard will be a single-span structure supported on concrete abutments to be located at the top of the creek banks. A crane will lift the bridge structure onto the abutments from a location at the top of the creek bank or the parking lot located to the south.
Underground utilities, such as storm drain pipes will be constructed and/or relocated, as necessary, to accommodate the proposed trail.
Existing ramps and the bottom of the creek will be traversed by vehicles. In areas of the creek bottom where concrete benching exists, the contractor will use temporary fill to allow vehicles to drive in these areas.
Finishing construction activities would include landscaping and soil stabilizing with replanting. Temporary irrigation is likely. The trail will have some signs placed in appropriate locations, and the pavement will have paint striping.
3.2.3 Environmental Avoidance and Minimization Measures
The proposed trail is located within and adjacent to the ecologically-sensitive Saratoga Creek riparian corridor. Within the project limits, there is a substantial amount of mature riparian habitat along the creek, including many large trees. A key objective of the City’s trail design team was to formulate a
Saratoga Creek Trail Initial Study City of Santa Clara 9 June 2016 design that avoids and minimizes impacts to this habitat to the greatest extent practicable. As examples, during trail design, impact avoidance and minimization was implemented through the use of retaining walls, using horizontal adjustments to avoid trees, narrowing the trail width in places, switching from one side of the creek to the other to avoid impacts, and utilizing existing paths. Further, all work or construction access in the Saratoga Creek streambed would be restricted to the dry season. In addition to the above-described avoidance measures built into the design, the project will use construction measures including BMPs, water pollution prevention, erosion control, and tree root protection to further minimize impacts.
Where impacts to biological resources within the Saratoga Creek riparian corridor could not be avoided, mitigation in the form of replacement habitat is included as part of the project. This mitigation, which is described in Section 4.4, Biological Resources, would reduce the effects of the project on biological resources to a less than significant level.
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SECTION 4.0 SETTING, ENVIRONMENTAL CHECKLIST AND IMPACTS
This section describes the existing environmental conditions on and near the project area, as well as environmental impacts associated with the proposed project. The environmental checklist, as recommended in the California Environmental Quality Act (CEQA) Guidelines, identifies environmental impacts that could occur if the proposed project is implemented.
The right-hand column in the checklist lists the source(s) for the answer to each question. The sources cited are identified at the end of this section. Mitigation measures are identified for all significant project impacts. “Mitigation Measures” are measures that will minimize, avoid, or eliminate a significant impact (CEQA Guidelines §15370). Measures that are proposed by the applicant that will further reduce or avoid already less than significant impacts are categorized as “Avoidance Measures.”
Since the project’s impacts are to be measured against a baseline that consists of the existing physical conditions, little or no physical impact would occur in many of the resource areas typically evaluated in an Initial Study. No impacts would occur because the existing functional land uses would not be physically modified, would not have a change in land use, and/or have any increase in capacity/density above their existing operation under the proposed project. Section 4.1 of this document is a checklist of those resource areas that would not experience measurable impacts from the proposed project.
The resource areas within which the proposed project may result in some impacts or changes were identified as: Aesthetics, Air Quality, Biology, Cultural Resources, Greenhouse Gas Emissions, Hazardous Materials, Hydrology, Land Use, Noise, and Recreation. Each of those resource areas are addressed separately and in greater detail in Sections 4.2-4.11 of this report.
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4.1 AREAS OF NO MEASURABLE IMPACT
4.1.1 Agricultural and Forest Resources
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Convert Prime Farmland, Unique Farmland, 1-3 or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? 2. Conflict with existing zoning for agricultural 1-3 use, or a Williamson Act contract? 3. Conflict with existing zoning for, or cause 1-3 rezoning of, forest land (as defined in Public Resources Code section 12220(g)), timberland (as defined by Public Resources Code section 4526), or timberland zoned Timberland Production (as defined by Government Code section 51104(g))? 4. Result in a loss of forest land or conversion of 1-3 forest land to non-forest use? 5. Involve other changes in the existing 1-3 environment which, due to their location or nature, could result in conversion of Farmland, to non-agricultural use or conversion of forest land to non-forest use?
4.1.2 Geology and Soils
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving: a. Rupture of a known earthquake fault, as 1-3 described on the most recent Alquist- Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? (Refer to Division of Mines and Geology Special Publication 42.)
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Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: b. Strong seismic ground shaking? 1-3 c. Seismic-related ground failure, including 1-3 liquefaction? d. Landslides? 1-3 2. Result in substantial soil erosion or the loss of 1-3 topsoil? 3. Be located on a geologic unit or soil that is 1-3 unstable, or that will become unstable as a result of the project, and potentially result in on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? 4. Be located on expansive soil, as defined in 1-3 Section 1802.3.2 of the California Building Code (2007), creating substantial risks to life or property? 5. Have soils incapable of adequately supporting 1-3 the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater?
4.1.3 Mineral Resources
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Result in the loss of availability of a known 1-3 mineral resource that will be of value to the region and the residents of the state? 2. Result in the loss of availability of a locally- 1-3 important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan?
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4.1.4 Population and Housing
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Induce substantial population growth in an 1-3 area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? 2. Displace substantial numbers of existing 1-3 housing, necessitating the construction of replacement housing elsewhere? 3. Displace substantial numbers of people, 1-3 necessitating the construction of replacement housing elsewhere?
4.1.5 Public Services
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated 1. Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, the need for new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services:
Fire Protection? 1-3 Police Protection? 1-3 Schools? 1-3 Parks? 1-3 Other Public Facilities? 1-3
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4.1.6 Transportation Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Conflict with an applicable plan, ordinance or 1-3 policy establishing measures of effectiveness for the performance of the circulation system, taking into account all modes of transportation including mass transit and non- motorized travel and relevant components of the circulation system, including but not limited to intersections, streets, highways and freeways, pedestrian and bicycle paths, and mass transit? 2. Conflict with an applicable congestion 1-3 management program, including, but not limited to level of service standards and travel demand measures, or other standards established by the county congestion management agency for designated roads or highways? 3. Result in a change in air traffic patterns, 1-3 including either an increase in traffic levels or a change in location that results in substantial safety risks? 4. Substantially increase hazards due to a design 1-3 feature (e.g., sharp curves or dangerous intersections) or incompatible land uses (e.g., farm equipment)? 5. Result in inadequate emergency access? 1-3 6. Conflict with adopted policies, plans, or 1-3 programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities?
4.1.7 Utilities and Service Systems
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Exceed wastewater treatment requirements of 1-3 the applicable Regional Water Quality Control Board?
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Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 2. Require or result in the construction of new 1-3 water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? 3. Require or result in the construction of new 1-3 stormwater drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? 4. Have sufficient water supplies available to 1-3 serve the project from existing entitlements and resources, or are new or expanded entitlements needed? 5. Result in a determination by the wastewater 1-3 treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments? 6. Be served by a landfill with sufficient 1-3 permitted capacity to accommodate the project’s solid waste disposal needs? 7. Comply with federal, state and local statutes 1-3 and regulations related to solid waste?
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4.2 AESTHETICS
4.2.1 Setting
The City of Santa Clara Parks & Recreation Department (Department) is responsible for maintaining and programming the various parks and recreation facilities, and works cooperatively with public agencies in coordinating all recreational activities within the City. Overall, the Department maintains and operates Central Park (52 acres), 25 neighborhood parks (122.67 acres), five mini parks (2.59 acres), public open space (16.13 acres of improved area and 40.08 acres of unimproved area for a total of 56.21 acres), recreation facilities (approximately 14.9 acres, excluding the Santa Clara Golf and Tennis Club and the Santa Clara Police Activities League Bicycle Motocross, recreation trails (3.7 acres), and joint use facilities (47.5 acres) throughout the City, totaling approximately 252.5 improved acres. Community parks are over 15 acres, neighborhood parks are one to fifteen acres and mini parks are typically less than one acre in size.
The proposed trail alignment is located within the existing Saratoga Creek channel, which is an engineered channel with dense riparian vegetation. The northernmost point of the project creek segment is located within Central Park. Saratoga Creek is located along the southern boundary of the park, adjacent to a surface parking lot. The lot is set back from the street frontage by a six-foot wide sidewalk and landscaping. Mature trees are located within and around the parking lot. On the park side, the creek channel is adjacent to a maintenance road, mature trees and grassland.
Currently, the area west of Saratoga Creek contains group and individual picnic facilities, playgrounds, restroom facilities, an amphitheater, two lighted tennis courts, basketball courts, the Veterans Memorial, and a Community Recreation Center. East of the creek is the George F. Haines International Swim Center, Bob Fatio Sports Center (including Tony Sanchez Field and a second lighted softball field), the Santa Clara Tennis Center with eight lighted tennis courts and a practice wall, open space, a lake, large group picnic areas, restroom facilities, a lawn bowling green, and exercise course, and the Central Park Library.
The southernmost point of the project creek segment is located within Homeridge Park, a six-acre park with a children’s play area, basketball court, picnic facilities, and restroom facilities. The creek segment is concrete lined with mature trees on each side as it passes under Homestead Road and enters the park. In this location, the creek segment is adjacent to a two-story apartment complex and a single-family house. The house has a minimal setback from the riparian corridor. A surface parking area for the apartment complex abuts the creek channel.
Between Central Park and Homeridge Park, the creek channel is surrounded by single-family houses, townhouses, an electrical sub-station, a small retail center, and the temporary staging area for the residential development on the Kaiser site. The residential neighborhood surrounding the creek segment was primarily constructed in the 1960s, and is a mix of one- and two-story houses, small apartments, and one- to two-story retail buildings in varying styles. Between Kiely Boulevard and Homestead Road, views of the creek are limited.
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4.2.1.1 Scenic Views and Resources
The project site and the surrounding area are relatively flat and, as a result, the site is only visible from the immediate area. The project area is not located within a designated scenic area or corridor based on the City of Santa Clara General Plan. While the creek itself, along with Central Park and Homeridge Park could be considered scenic, there are no formally designated scenic views or resources within the project area.
4.2.1.2 Light and Glare
Sources of light and glare are abundant in the urban environment of the project area, including, but not limited to, streetlights, parking lot lights, security lights, vehicular headlights, internal building lights, and reflective building surfaces and windows. The creek segment is not lit.
4.2.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Have a substantial adverse effect on a scenic 1-3 vista? 2. Substantially damage scenic resources, 1-3 including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? 3. Substantially degrade the existing visual 1-3 character or quality of the site and its surroundings? 4. Create a new source of substantial light or 1-3 glare which will adversely affect day or nighttime views in the area?
4.2.2.1 Aesthetic Impacts
The proposed trail alignment is within the Saratoga Creek channel which is located within an urban area of mixed uses (commercial, residential, and parkland) that has no designated scenic resources. Construction of the proposed trail would alter the visual character of this area by removing some of the existing trees in and around the creek, adding access ramps from Kiely Boulevard and Homestead Road, installing a pedestrian bridge adjacent to Kiely Boulevard, and adding a paved trail.
While there is a significant amount of development within the project area, the proposed trail would only be visible from within the creek and land immediately adjacent to the creek. The adjacent residential development would have little to no view of the trail due to existing fences and vegetation. With the planting of new trees along the trail alignment, the visual character of the project area would not change substantially with implementation of the project. (Less Than Significant Impact)
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There is no lighting proposed for the creek trail. As a result, the project would not create a new source of light or glare which would adversely impact day or nighttime views in the area. (No Impact)
4.2.3 Conclusion
Implementation of proposed trail project would have a less than significant impact on visual character of the project area. (Less Than Significant Impact)
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4.3 AIR QUALITY
4.3.1 Setting
4.3.1.1 Background Information
Air quality and the amount of a given pollutant in the atmosphere are determined by the amount of a pollutant released and the atmosphere’s ability to transport and dilute the pollutant. The major determinants of transport and dilution are wind, atmospheric stability, terrain, and for photochemical pollutants, sunshine.
The Bay Area typically has moderate ventilation, frequent inversions that restrict vertical dilution, and terrain that restricts horizontal dilution. These factors give the Bay Area a relatively high atmospheric potential for pollution.
The Bay Area Air Quality Management District (BAAQMD) monitors air quality at several locations within the San Francisco Bay Air Basin. The monitoring site closest to the project alignment is located near downtown San José. As shown in Table 4.3-1, violations of State and Federal standards at the downtown monitoring station during the 2013-2015 (the most current years that data is 2 available) period include high levels of ozone, PM10, and PM2.5. Violations of the carbon monoxide (CO) standard have not been recorded since 1992.
Table 4.3-1: Number of Ambient Air Quality Standards Violations and Highest Concentrations (2013-2015) Days Exceeding Standard Pollutant Standard 2013 2014 2015 SAN JOSÉ STATION State 1-hour 1 0 0 Ozone Federal 8-hour 1 0 2 Federal 8-hour 0 0 0 Carbon Monoxide State 8-hour 0 0 0 Nitrogen Dioxide State 1-hour 0 0 0 Federal 24-hour 0 0 0 PM10 State 24-hour 5 1 1 PM2.5 Federal 24-hour 6 2 2
The pollutants known to exceed the State and Federal standards in the project area are regional pollutants. Ozone, PM10, and PM2.5 are all considered regional pollutants because the concentrations are not determined by proximity to individual sources, but rather show a relative uniformity over a region.
2 PM refers to Particulate Matter. Particulate matter is referred to by size (i.e., 10 or 2.5) because the size of particles is directly linked to their potential for causing health problems.
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The Federal Clean Air Act (CAA) and the California CAA of 1988 require that the California Air Resources Board (CARB), based on air quality monitoring data, designate portions of the State where Federal or State ambient air quality standards are not met as “nonattainment areas”. Because of the differences between the Federal and State standards, the designation of “nonattainment area” is different under the Federal and State legislation. Under the California CAA, Santa Clara County is a nonattainment area for ozone and PM10. The County is either in attainment or unclassified for other pollutants. Under the Federal CAA, the entire Bay Area region is classified as nonattainment for the 24-hour PM2.5 standard. The U.S. Environmental Protection Agency (EPA) grades the region as in attainment or unclassified for all other air pollutants, included PM10.
4.3.1.2 Sensitive Receptors
BAAQMD defines sensitive receptors as facilities where population groups that are particularly sensitive to the effects of air pollutants (i.e., children, the elderly, and people with illness) are likely to be located. Examples include schools, hospitals, and residential areas. The nearest sensitive receptors to the project alignment are the adjacent residential properties and the school east of the project creek segment.
4.3.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Conflict with or obstruct implementation of 1-5 the applicable air quality plan? 2. Violate any air quality standard or contribute 1-5 substantially to an existing or projected air quality violation? 3. Result in a cumulatively considerable net 1-5 increase of any criteria pollutant for which the project region is classified as non-attainment under an applicable federal or state ambient air quality standard including releasing emissions which exceed quantitative thresholds for ozone precursors? 4. Expose sensitive receptors to substantial 1-5 pollutant concentrations? 5. Create objectionable odors affecting a 1-3 substantial number of people?
4.3.2.1 Operational Impacts
Use of the proposed trail by pedestrian and bicyclists would not generate any air pollutants and, as a result, would have no impact on local or regional air quality. Expansion of the trail system and enhancement of existing pedestrian facilities could result in increased trail usage which would
Saratoga Creek Trail Initial Study City of Santa Clara 21 June 2016 incrementally reduce traffic trips in the project area. Any decrease in automobile trips associated with the proposed project would be a beneficial impact. (No Impact)
4.3.2.2 Construction-Related Impacts
Construction of the proposed trail and pedestrian improvements would involve site grading, trenching, paving, support wall and bridge construction, and landscape planting. Construction activities would occur over approximately 10 months over two construction seasons (five months each during the dry season).
Construction activities have a high potential for creating air pollutants. In addition to the dust created during excavation, substantial dust emissions could be created as debris and soil are loaded into trucks for removal. After excavation, construction activities would continue to affect local air quality. Construction activities would generate exhaust emissions from vehicles/equipment and fugitive particulate matter emissions. Asphalt used in paving is a source of organic gases for a short time after its application.
According to the BAAQMD CEQA Guidelines, emissions of ozone precursors (reactive organic gases [ROG] and Nitrogen Oxides [NOx]) and CO related to construction equipment are already included in the emission inventory that is the basis for regional air quality plans and, as such, are not expected to impede attainment or maintenance of ozone and CO standards in the Bay Area. The effects of construction activities would be increased dustfall and locally elevated levels of PM10 and PM2.5 downwind of construction activity, which would be a significant temporary impact.
Impact AIR - 1: Construction of the proposed project would result in the exposure of sensitive receptors (i.e., residents and school children) to temporary air quality impacts associated with dust and particulate matter generation. (Significant Impact)
Mitigation and Avoidance Measures
BAAQMD has prepared a list of dust control measures that can reduce construction impacts to a less than significant level. The following mitigation measures shall be implemented during all phases of construction on the project site:
MM AIR – 1.1: Water all active construction areas at least twice daily or as often as needed to control dust emissions.
MM AIR – 1.2: Cover all trucks hauling soil, sand, and other loose materials.
MM AIR – 1.3: Pave, apply water twice daily or as often as necessary, to control dust, or apply non-toxic soil stabilizers on all unpaved access roads, parking areas and staging areas at construction areas.
MM AIR – 1.4: Sweep daily, or as often as needed, with water sweepers all paved access roads, parking areas and staging areas at the construction site to control dust.
Saratoga Creek Trail Initial Study City of Santa Clara 22 June 2016
MM AIR – 1.5: Sweep public streets daily in the vicinity of the project site, or as often as needed, to keep streets free of visible soil material. MM AIR – 1.6: Hydroseed or apply non-toxic soil stabilizers to inactive construction areas.
MM AIR – 1.7: Enclose, cover, water twice daily, or apply non-toxic soil binders to exposed stockpiles (dirt, sand, etc.).
MM AIR – 1.8: Limit vehicle traffic speeds on unpaved roads to 15 mph.
MM AIR – 1.9: Replant vegetation in disturbed areas as quickly as possible.
MM AIR – 1.10: Install sandbags or other erosion control measures to prevent silt runoff from public roadways.
4.3.3 Conclusion
Implementation of the proposed mitigation measures would reduce air quality impacts associated with construction of the proposed project to a less than significant level. Use of the proposed trail would not generate any air pollutants and would have no impact on local or regional air quality. (Less Than Significant Impact With Mitigation)
Saratoga Creek Trail Initial Study City of Santa Clara 23 June 2016
4.4 BIOLOGICAL RESOURCES
The following discussion is based on a biological report and wetland delineation prepared by H.T. Harvey & Associates in June 2016. Copies of these reports are provided in Appendix A of this report.
4.4.1 Setting
The proposed trail alignment is located within a riparian corridor that traverses a developed urban area. A reconnaissance-level field survey identified three general biotic habitats within the project site: developed/landscaped, riparian woodland, and stream. These habitats are described in detail below and are depicted on Figure 4.4-1.
4.4.1.1 Developed/Landscaped Habitat
Vegetation
Developed/landscaped habitat makes up approximately 1.58 acres (49 percent) of the 3.22- acre site and is found outside the riparian corridor. The habitat includes portions of both parks and the maintenance road between Homestead Road and Kiely Boulevard. Within the parks, the habitat includes maintained lawns and mature trees (redwood and coast live oak). The maintenance road is lined with trees and is comprised of a permeable gravel surface above the top of bank, on the southern side of the creek. No special-status plant species were identified.
Wildlife
Breeding birds within the developed habitat of the project site include American crow, American robin, red-shouldered hawk, Anna’s hummingbird, northern mockingbird, and mourning dove. Urban adapted mammals include raccoon, Virginia opossum, and Norway rat. A small number of reptile species, such as the western fence lizard, may also occur within these areas.
The overcrossings at Kiely Boulevard and Homestead Road contain a limited number of small crevices that could provide roosting habitat for a small number of bats, such as the California myotis. There are, however, no features capable of supporting large bat roosts, and no evidence of large swallow colonies is present on these bridges.
Saratoga Creek Trail Initial Study City of Santa Clara 24 June 2016 Sheet 1
H Matchline to Sheet 2 o m es te a d Legend R d Overview Project Site Boundary (3.22 ac) Sheet 2 Permanent Impact (1.23 ac)
Temporary Impact (1.39 ac) Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, User Community Top of Bank 100 50 0 100
25 Habitat Feet Developed/Landscaped (1.58 ac) Sheet 1
Riparian Woodland (0.92 ac)
Stream (0.72 ac)
d p lv B ly ie K Matchline to Sheet 1 Sheet to Matchline gp gp
jp Sheet 2 Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, User Community
Source: H.T. Harvey & Associates, June 2016.
EXISTING BIOLOGICAL HABITATS FIGURE 4.4-1
4.4.1.2 Riparian Woodland Habitat
Vegetation
Riparian woodland habitat makes up approximately 0.92 acres (29 percent) of the total site area. Along the project segment of Saratoga Creek, the riparian woodland is primarily an engineered system with many of the mature trees having been planted as mitigation for a Santa Clara Valley Water District (SCVWD) flood control project in 1987-88. Most trees within the riparian corridor are coast live oak, valley oak, California black walnut, blue elderberry, and western sycamore. The understory shrub vegetation includes coyote brush, toyon, coffeeberry, and California Rose. The high portion of the banks, near the shoulders, are well vegetated with native species. Lower portions of the bank, near the toe of slope, are dominated by non-native herbaceous vegetation such as Smilo grass, drug fumitory, fennel, and ivy. The low bank does not support native riparian understory herbaceous vegetation.
The overhanging outer edge of the canopy of trees rooted in the banks appears to meet the State definition for riparian jurisdiction under the California Department of Fish and Wildlife (CDFW). No special-status plant species were identified and the existing woodland does not qualify as a native stand or a natural community.
Wildlife
Riparian habitats in California generally support diverse animal communities and contribute a disproportionately high amount to landscape-level species diversity. In addition to providing breeding, foraging, and roosting habitat for a diverse array of animals, riparian communities provide movement corridors for some species, connecting a variety of habitats throughout a region.
The project creek segment has high value to wildlife. The intermittent presence of water in the creek and the streamside vegetation support abundant invertebrate fauna, which provides ample foraging opportunities for insectivores. Breeding birds include Anna’s hummingbird, dark-eyed junco, downy woodpecker, spotted towhee, Cooper’s hawk, chestnut-backed chickadee, bushtit, white-breasted nuthatch, and many others. Numerous other bird species use the site for foraging and cover during migration and winter; these include the white-crowned sparrow, yellow-rumped warbler, and ruby- crowned kinglet.
Trees on-site with cavities or loose bark may provide roosting habitat for individual bats, including the California myotis. The hoary bat and western red bat may utilize the project area during migration and winter. While a mixed understory typically supports a variety of mammals, reptiles and amphibians, the dense urban development surrounding the project site limits species diversity to those typically associated with urban environments. Species within the project site include the fox squirrel, Virginia opossum, raccoon, striped skunk, Norway rat, and house mouse. These species use
Saratoga Creek Trail Initial Study City of Santa Clara 26 June 2016 the riparian habitats along Saratoga Creek for dispersal and habitat. The Sierran chorus frog, western fence lizard and slender salamander occur here as well.
Special-Status Species3
The pallid bat is a species of special concern and occurs throughout California with the exception of the northwest corner of the state and the high Sierra Nevada. Pallid bats are typically found in oak savannah and in open dry habitats with rocky areas, trees, buildings, or bridge structures that are used for roosting. Coastal colonies commonly roost in deep crevices in rocky outcroppings, in buildings, under bridges, and in the crevices, hollows, and exfoliating bark of trees. Night roosts often occur in open buildings, porches, garages, highway bridges, and mines. Pallid bat roosts are very susceptible to human disturbance.
Small numbers of pallid bats may roost in crevices or under exfoliating bark in trees within the project site and may forage over the site; however, the absence of trees with large cavities precludes the presence of a large colonial roost or maternity colony.
4.4.1.3 Stream Habitat
Vegetation
The stream has engineered riparian banks and supports intermittent flows associated with precipitation events and seasonal groundwater rise. The stream habitat makes up approximately 0.72 acres (22 percent) of the total site area. The stream was dry during a site visit on January 12 (prior to any rain event) and had between 0.5 to 1.0 feet of water on January 20th, after a rain event.
The stream bed is approximately 15-20 feet wide with a primarily pebble and cobble bottom. Portions of the stream bed are covered in concrete. There is no vegetation within the streambed and no herbaceous wetland vegetation is present. No special-status plant species were identified.
Waters of the United States (U.S.)/State
Saratoga Creek is considered to be jurisdictional waters of the U.S. up to the ordinary high water mark. No hydrophytes (water-loving plants) were observed in the streambed and, as a result, there are no wetlands on-site.
3 The term special-status species refers to those that are candidate/listed as threatened or endangered under the Federal and/or California Endangered Species Acts. It also includes CDFW’s California Species of Special Concern, which serve as a “watch list.” Such species either are of limited distribution or the extent of their habitats has been reduced substantially, such that threat to their populations may be imminent. Thus, their populations should be monitored. They may receive special attention during environmental review as potential rare species, but do not have specific statutory protection.
Saratoga Creek Trail Initial Study City of Santa Clara 27 June 2016
Waters of the State occur along Saratoga Creek to the top of bank and up to the edge of the canopy of the trees rooted in the banks.
Wildlife
The intermittent nature of Saratoga Creek within the project segment, as well as the steep banks and lack of in-stream vegetation, greatly reduces the quality of the habitat for fish and aquatic wildlife species. Nevertheless, when water is present several native and introduced fish species are found in the creek including the Sacramento sucker and rainbow trout. Amphibians such as the Sierran chorus frog and non-native American bullfrog are also present.
Waterbirds including mallards, green heron, and belted kingfisher forage within the stream, and bats, including the Yuma myotis and big brown bat, forage aerially on insects over the creek.
Special-Status Species
The western pond turtle is a species of special concern that occurs in ponds, streams, and other wetland habitats in the Pacific slope drainages of California and northern Baja California, Mexico. Ponds or slackwater pools with suitable basking sites (such as logs) are an important habitat component for this species. Western pond turtles do not typically occur along high-gradient streams. Females lay eggs in upland habitats, in clay or silty soils in unshaded (often south-facing) areas up to 0.25 miles from aquatic habitat, and juveniles feed and grow in shallow aquatic habitats (often creeks) with emergent vegetation and ample invertebrate prey. Nesting habitat is typically found within 600 feet of aquatic habitat, but if no suitable nesting habitat can be found close by, adults may travel overland considerable distances to nest.
Within the project site, Saratoga Creek’s steep banks, mature riparian growth, lack of suitable basking sites, and proximity to dense urban development make it unsuitable for resident or breeding western pond turtles. A small number of individual turtles may, however, disperse through the project site when water flows within the creek.
No other special-status animal species are anticipated to be present within the project site; see Appendix A for details.
4.4.1.4 Tree Protection
The City of Santa Clara claims jurisdiction over all trees along public rights-of-way (Santa Clara City Code, Chapter 12.35). The City takes full authority for removal or pruning trees along public rights- of-way. Other protected trees may be pruned, but not topped without requesting authorization. However, protected trees may not be removed nor may grading be performed within a 10-ft radius of these trees unless explicit permission has been granted by the City, either via a Protected Tree Removal Permit or approval of development plans. The City may require replacement plantings or other mitigation measures as a condition of approval.
The following General Plan policies are applicable to the proposed project.
Saratoga Creek Trail Initial Study City of Santa Clara 28 June 2016
Policy 5.3.1-P10: Provide opportunities for increased landscaping and trees in the community, including requirements for new development to provide street trees and a minimum 2:1 on- or off- site replacement trees removed as part of the proposal to help increase the urban forest and minimize the heat island effect.
Policy 5.10.1-P3: Require preservation of all City-designated heritage trees listed in the Heritage Tree Appendix 8.10 of the General Plan.
Policy 5.10.1-P4: Protect all healthy cedars, redwoods, oaks, olives, bay laurel and pepper trees of any size, and all other trees over 36 inches in circumference measured from 48 inches above-grade on private and public property as well as in the public right-of-way.
As discussed subsequently in Section 4.4.2, many of the trees that will be impacted by the project qualify as those subject to the Santa Clara City Code and applicable City policies.
4.4.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Have a substantial adverse effect, either 1-3, 6 directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Wildlife or US Fish and Wildlife Service? 2. Have a substantial adverse effect on any 1-3, 6 riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations, or by the California Department of Fish and Wildlife or US Fish and Wildlife Service? 3. Have a substantial adverse effect on federally 1-3, 6 protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? 4. Interfere substantially with the movement of 1-3, 6 any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites?
Saratoga Creek Trail Initial Study City of Santa Clara 29 June 2016
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 5. Conflict with any local policies or ordinances 1-3, 6 protecting biological resources, such as a tree preservation policy or ordinance? 6. Conflict with the provisions of an adopted 1-3, 6 Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan?
4.4.2.1 Conflicts with Adopted Conservation Plans
There are no adopted habitat conservation plans, natural community conservation plans, or other conservation plans that pertain to the project site. Therefore, the proposed project would not conflict with any adopted habitat conservation plan, natural community conservation plan, or other approved local, regional, or State habitat conservation plan. (No Impact)
4.4.2.2 Impacts to Developed/Landscaped Habitat
As shown in Table 4.4-1, implementation of the proposed project would result in permanent impacts to up to 0.65 acres of developed/landscaped habitat resulting from the conversion or alteration of upland habitats to asphalt or concrete surface trails and grade modifications from cut and fill work. In addition, temporary impacts would occur to up to 0.49 acres of habitat during construction. While the composition of vegetation within the developed/landscaped habitat on-site would be altered and/or diminished, this habitat type is abundant regionally and does not represent sensitive or valuable habitat. Furthermore, the number of individual plant or animal species that could be impacted is very small and would not substantially reduce regional populations of these species. (Less Than Significant Impact)
Table 4.4-1: Summary of Biological Habitat Impacts Habitat Permanent Temporary Significant Mitigation Type Impacts Impacts Impact? Developed/Landscaped 0.65 acres 0.49 acres No n/a Riparian Woodland & Plant 306 trees; see 0.54 acres/94 trees 0.21 Yes Tree Removal Table 4.4-2 Implement construct- Stream 0.03 0.69 Yes ion BMPs; see text. Source: H.T. Harvey & Associates, 2016.
4.4.2.3 Impacts to Riparian Woodland Habitat and Tree Removal
Removal of up to 94 trees and permanent impacts to 0.54 acres and temporary impacts up to 0.21 acres of riparian woodland would result from Project implementation.
Saratoga Creek Trail Initial Study City of Santa Clara 30 June 2016
The project site contains both high quality and lower quality riparian habitat. The high quality habitat is a result of SCVWD tree and shrub mitigation plantings in the corridor in the late 1980s. Lower quality riparian habitat occurs around the street crossings where the overstory is absent and the understory and bank surface supports little vegetation because it is covered with riprap or gabions.
Impacts to riparian trees would occur from the removal of trees to allow for the construction of new access ramps and other project improvements. Indirect impacts to riparian woodland habitat could result from trail work that would occur immediately adjacent to, but outside the riparian corridor. The main portion of the trail between the proposed Homestead and Kiely undercrossings would, however, be installed within the existing maintenance road footprint and would not require grading or other construction activities that would impact adjacent trees. There are 189 trees within and immediately adjacent to the footprint of the proposed trail. Project implementation would result in the removal of up to 94 of the 189 trees, the majority of which are within riparian woodland, but a few of which are actually isolated from the corridor and located within the developed/landscaped habitat.
IMPACT BIO-1: Implementation of the proposed project would result in the loss of up to 94 trees within and adjacent to the riparian woodland habitat on the project site. (Significant Impact)
Mitigation and Avoidance Measures
The following mitigation measures would be implemented during project construction to reduce impacts from the loss of trees to a less than significant level.
MM BIO-1.1: The Project will comply with the City of Santa Clara General Plan policies and tree removal ordinance, and obtain a tree removal permit for all ordinance sized trees to be impacted. Trees to be removed will be replaced at the following ratios:
Table 4.4-2: Tree Replacement Ratios No. of No. of Trees to Mitigation Tree Species Replacement be Removed Ratio Trees Trees < 12 Inches in Diameter Oaks 29 5:1 145 Other Natives 40 3:1 120 Non-Natives 14 1:1 14 Trees >12 Inches in Diameter Oaks 9 3:1 27 Other Natives 0 2:1 0 Non-Natives 2 n/a 0 Total 94 306
Based upon a preliminary evaluation by the project’s restoration ecologists, the City has identified five locations along Saratoga Creek where mitigation plantings are
Saratoga Creek Trail Initial Study City of Santa Clara 31 June 2016
feasible. While none of the five locations by themselves are sufficiently large enough to provide all of the required mitigation, there is more than enough acreage if a combination of two or more of the sites are utilized. As shown on Figure 4.4-2, these five locations are as follows:
Bowers Park, where a diverse mix of native riparian tree and shrub plantings here would expand the SCVWD vegetation preserved along the west bank of Saratoga Creek; Two sites within Central Park that would expand the existing SCVWD vegetation preserve along the east and west banks of Saratoga Creek; A site along the east bank of Saratoga Creek in Homeridge Park; A site along the eastern lower banks of Saratoga Creek at Maywood Park.
At each of these five locations, there is an opportunity to strengthen the existing riparian habitat, remove invasive plant species, and add a band of oak woodland habitat to increase biological diversity and wildlife habitat area. Once the City determines which locations will be used, a Mitigation and Monitoring Plan (MMP) will be developed that will set forth the specifics regarding the layout and species of plantings, monitoring requirements (typically 10 years), and success criteria. The MMP will also specify remedial steps to be taken if the mitigation is not meeting the success criteria.4
4.4.2.4 Impacts Resulting from Damage to Trees during Construction
In addition to the 94 trees being directly impacted by the proposed trail, trees within the temporary staging areas and areas adjacent to the construction zones could be harmed during implementation of the proposed project if damage to tree canopies, roots, or trunks occurs. Such damage could result could result in the permanent loss of additional trees.
IMPACT BIO-2: Implementation of the proposed project could result in the damage or loss of mature trees located outside the project site. (Significant Impact)
Mitigation and Avoidance Measures
The following mitigation measures would be implemented during project construction to minimize the potential for tree loss due to damage from construction activities.
MM BIO-2.1: Trees that occur within the project impact area shall be protected during project construction. Protection measures shall include the establishment of Tree Protection Zones (TPZs), which at a minimum shall include the installation of a fence around the drip line of trees to remain in place, restricted construction activity within the dripline, and the posting of appropriate signage on the fence. Trees that are subject to ground-disturbing construction activities within any portion of their dripline will be
4 Compliance with this mitigation and the MMP will also be mandated by the U.S. Army Corps of Engineers, Regional Water Quality Control Board, and the CDFW as part of the conditions for obtaining permits from these agencies.
Saratoga Creek Trail Initial Study City of Santa Clara 32 June 2016 Overview
Bowers Park
Project Site
00.4
Miles EI Camino Real
San Tomas Expy Tomas San
Central Park
Homeridge Park
Maywood Park
Legend
Potential Mitigation Sites
0.2 0.1 00.2
Miles
Source: H.T. Harvey & Associates, April 2016.
MITIGATION SITES FIGURE 4.4-2
33
considered lost, unless a certified arborist determines that the tree is unlikely to be severely damaged or killed by such activities.
MM BIO-2.2: Trees outside the project area that are considered lost due to damage from project construction will be replaced consistent with the tree replacement ratios identified in MM BIO-1.1.
4.4.2.5 Impacts to Stream Habitat
Development of the project would result in permanent impacts to approximately 0.03 acres of aquatic habitat on-site from installation of the concrete undercrossings and trail construction. The trail undercrossings would be constructed from concrete poured into forms and would place permanent fill in the creek bed and banks. At the proposed undercrossing locations, the creek bed already has a concrete bottom and in several areas the crossings have concrete aprons upstream and downstream beyond the crossing itself. Therefore, while undercrossing installation would narrow the active portion of the streambed, it would not change the ecological character of the stream. Indirect permanent impacts would result from shading by the new approximately 12-foot wide pedestrian bridge on the western side of Kiely Boulevard. The bridge would be a clear-span bridge placed with abutments above the top of bank to avoid impacts to jurisdictional waters and riparian habitat. (Less Than Significant Impact)
Implementation of the proposed project would have a substantial adverse effect on water quality within Saratoga Creek due to the amount of cut/fill work on the riparian banks, placement of new structure fill within the channel, access within the streambed for construction vehicles, and riparian tree removal. In addition, approximately 0.69 acres of stream habitat would be temporarily impacted from dry season construction access in the creek bed and temporary fill placed during access.
For a discussion of impacts associated with degradation of water quality resulting from construction activities, please see Section 4.8.2.2, Water Quality Impacts.
4.4.2.6 Impacts from Invasive Weeds
Invasive weeds can occur in all habitat types and can be difficult to eradicate. One of the characteristics of invasive species that make them successful is that many non-native, invasive plant species produce seeds that germinate readily following disturbance. In addition, newly disturbed areas are highly susceptible to colonization by non-native, invasive species that occur locally, or whose propagules are brought in by personnel, vehicles, and other equipment. There are several noxious weed species currently present in the project site, including Bermuda grass, French broom, fennel, English ivy, Bermuda buttercup, ripgut brome, and Himalayan blackberry. Construction activities would result in soil disturbance over the entire project site. Areas of disturbance could serve as the source for promoting the spread of these non-native species, which could degrade the ecological value of the project site, and adversely affect native plants and wildlife that occur there.
Impact BIO-3: Construction activities could result in the introduction of invasive weeds into sensitive habitats. (Significant Impact)
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Mitigation and Avoidance Measures:
The following mitigation measures are proposed to reduce impacts from invasive species to a less than significant level.
MM BIO-3.1: During construction activities, all seeds and straw materials used on-site shall be weed-free rice straw (or similar material), and all gravel and fill material shall be certified weed-free. Construction vehicles and all equipment shall be washed (including wheels, undercarriages, and bumpers) before entering the project site. Vehicles shall be cleaned at existing construction yards or car washes.
MM BIO-3.2: Following construction of the project, a standard erosion control seed mix from a local source shall be planted within the temporary impact zones on any disturbed ground that will not be under hardscape, landscaped, or maintained.
With implementation of the listed mitigation, identified impacts from invasive weeds would be reduced to less than significant.
4.4.2.7 Impacts to Roosting Bats
The proposed project would result in the removal of trees that may be used as dayroosts by individual pallid bats. As a result, there is some probability for bats to be physically injured or killed, stressed, or to face increased predation. The project would not, however, result in the loss of high-quality roost sites, large maternity colonies, or large numbers of bats because the site does not have suitable habitat. While some bats may be impacted by implementation of the project, only a small percentage of the regionally available riparian woodland foraging and roosting habitat would be affected. As a result, implementation of the proposed project would have a less than significant impact on pallid bats. (Less Than Significant Impact)
4.4.2.8 Impacts to Western Pond Turtles
The project would not result in the loss of pond turtle nests or suitable nesting habitat, or the permanent loss of dispersal or foraging habitat. There is a very low probability that individual western pond turtles would be directly impacted by construction activities within the creek channel. As a result, implementation of the proposed project would have a less than significant impact on western pond turtles. (Less Than Significant Impact)
4.4.2.9 Impacts to Raptors and Other Migratory Birds
The mature trees and open space areas within the riparian corridor and on adjacent properties could provide nesting and foraging habitat for raptors and other migratory birds. Nesting raptors are among the species protected under provisions of the Migratory Bird Treaty Act (MBTA) and California Fish and Game Code Sections 3503, 3503.5, and 2800 et seq. While the entire area is developed, raptors (such as falcons, hawks, eagles, and owls) and other migratory birds may utilize the large trees on-site or adjacent to the site for foraging or nesting. Construction disturbance near raptor nests can result in the incidental loss of fertile eggs or nestlings, or otherwise lead to nest abandonment in the trees adjacent to the northern boundary of the project site. Disturbance that
Saratoga Creek Trail Initial Study City of Santa Clara 35 June 2016 causes abandonment and/or loss of reproductive effort is considered a take under the Fish and Game code. Any loss of fertile eggs, nesting raptors, or any activities resulting in nest abandonment would constitute a significant impact.
Impact BIO-4: Construction activities associated with the proposed project could result in the loss of fertile eggs, nestlings, if present, or nest abandonment. (Significant Impact)
Mitigation and Avoidance Measures
The following mitigation measures, in conformance with the MBTA and the Fish and Game Code, will be implemented during construction to avoid abandonment of raptor and other protected migratory birds nests:
MM BIO 4-1: Tree removal and construction shall be scheduled to avoid the nesting season to the extent feasible. The nesting season for most birds, including most raptors in the San Francisco Bay Area, extends from February 1 through August 31.
MM BIO 4-2: If it is not feasible to schedule tree removal and construction between September and January, then pre-construction surveys for nesting birds shall be completed by a qualified ornithologist to ensure that no nests will be disturbed during project implementation. This survey shall be undertaken no more than seven days prior to the initiation of construction activities. During this survey, the ornithologist will inspect all trees and other potential nesting habitats (e.g., shrubs and buildings) in and immediately adjacent to the impact areas for nests. If an active nest is found sufficiently close to work areas to be disturbed by these activities, the ornithologist will determine the extent of a construction-free buffer zone to be established around the nest (typically 300 feet for raptors and 100 feet for other species), to ensure that no nests of species protected by the MBTA and California Fish and Game Code will be disturbed during construction of the project.
MM BIO 4-3: If construction activities will not be initiated until after the start of the nesting season, it is recommend that all potential nesting substrates (e.g., bushes, trees, grasses, and other vegetation) that are scheduled to be removed by the Project be removed prior to the start of the nesting season (e.g., prior to February 1). This will preclude the initiation of nests in this vegetation, and prevent the potential delay of the project due to the presence of active nests in these substrates.
4.4.3 Conclusion
The project would have a less than significant impact on biologic resources with implementation of the proposed mitigation measures. (Less Than Significant Impact With Mitigation)
Saratoga Creek Trail Initial Study City of Santa Clara 36 June 2016
4.5 CULTURAL RESOURCES
The following discussion is based on literature review prepared by Holman & Associates in January 2015.5 A copy of the report is available at the office of Planning and Inspection at Santa Clara City Hall.
4.5.1 Setting
4.5.1.1 Prehistoric Resources
Overview
Native Americans occupied Santa Clara Valley and the greater Bay Area for more than 1,000 years. The exact time period of the Ohlone (originally referred to as Costanoan) migration into the Bay Area is debated by scholars. Dates of the migration range between 3000 B.C. and 500 A.D. Regardless of the actual time frame of their initial occupation of the Bay Area and, in particular, Santa Clara Valley, it is known that the Ohlone had a well-established population of approximately 7,000 to 11,000 people with a territory that ranged from the San Francisco Peninsula and the East Bay south through the Santa Clara Valley and down to Monterey and San Juan Bautista.
The Ohlone lived in small villages referred to as tribelets. Each tribelet occupied a permanent primary habitation site and also had smaller resource procurement camps. The Ohlone, who were hunter/gatherers, traveled between their various village sites to take advantage of seasonal food resources (both plants and animals). During winter months, tribelets would merge to share food stores and engage in ceremonial activities.
4.5.1.2 Historic Subsurface Resources
Mission Period
Spanish explorers began coming to Santa Clara Valley in 1769. From 1769 to 1776, several expeditions were made during which time the explorers encountered the local Native American tribes. These expeditions led to the establishment of the California Missions, including the first Mission Santa Clara founded in 1777 near what is today the Kifer Road/De La Cruz Boulevard intersection. After being destroyed by flooding, a second Mission Santa Clara was constructed near the present day Martin Avenue/De La Cruz intersection. The third, fourth, and fifth Missions were constructed on what is today the Santa Clara University Campus, approximately 1.7 miles east of the project site. During the Mission period, the Mission controlled much of the land (approximately 80,000 acres) in Santa Clara Valley and the Native Americans were brought into the Mission, effectively ending the Ohlone’s traditional occupation of the valley.
5 The literature review referenced in this analysis was prepared for the City of Santa Clara’s proposed International Swim Center/Community Recreation Center project in Central Park. Due to the breadth of the scope of the literature review, the data provided is sufficient to assess any potential cultural resources impacts resulting from the proposed project.
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Post-Mission and American Period
In 1836, the Mission Santa Clara was officially secularized and the native population had diminished from a population peak of 10,000 in 1770 to 300. Lands previously belonging to the Mission were distributed through land grants. After the United States won the Mexican-American War (1846- 1848), Anglo-European settlers began to arrive in the Santa Clara Valley and the subsequent gold rush of 1849 further increased the local population. For most settlers, mining was not profitable and many people turned to farming. There is no documentation to indicate that the project area was utilized in any way prior to 1948 when farming is known to have occurred on-site. Farming operations continued until the late 1960’s when Central Park and the surrounding neighborhoods were constructed.
An archaeological report was completed in 1976 for the City of Santa Clara to evaluate the effects of various infrastructure projects, including a new traffic signal at the intersection of Kiely and Homestead. The report included a map that indicates that Central Park is an approximate location of an archaeological resource. No other documentation exists to determine what the resource might be or how the determination was made.
While there are no existing conditions or immediate evidence that would suggest the presence of subsurface historic or prehistoric resources on the project sites, the project is located within the riparian zone of Saratoga Creek. This is important because, based on historical records, as well as the pattern for the locations of numerous archaeological sites, such resources are frequently found along creeks in Santa Clara County. For this reason, the project alignment is considered culturally sensitive for subsurface archaeological resources.
4.5.1.3 Historic Structures
Based on available records, no structures adjacent to the creek segment are over 50 years old or listed on the City’s historic resources inventory.
4.5.1.4 Paleontological Resources
Paleontological resources are the fossilized remains of organisms from prehistoric environments found in a geologic strata. The project site is underlain by Holocene (basin) soil deposits.6 Geologic units of Holocene age are generally not considered sensitive for paleontological resources, because biological remains younger than 10,000 years are not usually considered fossils. These sediments have low potential to yield fossil resources or to contain significant nonrenewable paleontological resources; however, these recent sediments overlie sediments of older Pleistocene sediments with high potential to contain paleontological resources. These older sediments, often found at depths of 10 feet or more below the ground surface, have yielded the fossil remains of plants and extinct terrestrial Pleistocene vertebrates.
6 City of Santa Clara. Integrated Final Environmental Impact Report Draft General Plan 2010-2035. Page 323. January 2011.
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4.5.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Cause a substantial adverse change in the 1-3, 7 significance of an historical resource as defined in §15064.5? 2. Cause a substantial adverse change in the 1-3, 7 significance of an archaeological resource as defined in §15064.5? 3. Directly or indirectly destroy a unique 1-3, 7 paleontological resource or site, or unique geologic feature? 4. Disturb any human remains, including those 1-3, 7 interred outside of formal cemeteries?
4.5.2.1 Prehistoric and Historic Subsurface Resources Impacts
Prehistoric and Historic Resources
While development the project area surrounding the creek segment did not begin until 1948, creeks within Santa Clara County typically have high archaeological sensitivity because they are frequently found to contain subsurface artifacts associated with the prehistoric and historic occupation of Santa Clara. Based on this fact, development of the proposed project could result in the exposure or destruction of as yet unrecorded subsurface prehistoric and historic archaeological artifacts and/or human remains.
Impact CUL – 1: Subsurface cultural resources could be uncovered and impacted during construction of the proposed project. (Significant Impact)
Mitigation and Avoidance Measures
The following mitigation measures will be implemented during construction to avoid significant impacts to unknown subsurface cultural resources.
MM CUL-1.1: A qualified archaeologist will be on site to monitor the initial excavation of native soil once all pavement and engineered soil is removed from the project site. After monitoring the initial excavation, the archaeologist will make recommendations for further monitoring if it is determined that the site has cultural resources. If the archaeologist determines that no resources are likely to be found on site, no additional monitoring will be required.
MM CUL-1.2: In the event that prehistoric or historic resources are encountered during excavation and/or grading of the site, all activity within a 50-foot radius of the find will be stopped, the Director of Planning and Inspection will be
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notified, and the archaeologist will examine the find and make appropriate recommendations prior to issuance of building permits. Recommendations could include collection, recordation, and analysis of any significant cultural materials. A report of findings documenting any data recovery during monitoring would be submitted to the Director of Planning and Inspection.
MM CUL-1.3: In the event that human remains are discovered during excavation and/or grading of the site, all activity within a 50-foot radius of the find will be stopped. The Santa Clara County Coroner will be notified and shall make a determination as to whether the remains are of Native American origin or whether an investigation into the cause of death is required. If the remains are determined to be Native American, the Coroner will notify the Native American Heritage Commission (NAHC) immediately. Once NAHC identifies the most likely descendants, the descendants will make recommendations regarding proper burial, which will be implemented in accordance with Section 15064.5(e) of the CEQA Guidelines.
With implementation of these measures, impacts to unknown subsurface prehistoric, historic, and archaeological resources would be less than significant. (Less Than Significant Impact with Mitigation)
Historic Structures
There are no historic structures immediately adjacent to the project site. Therefore, implementation of the proposed project would have no impact on any designated historic structures. (No Impact)
Paleontological Resources
Excavation within the creek channel would not exceed 10 feet in depth and it is improbable that paleontological resources would be discovered on-site due to the distance of the site from the San Francisco Bay. In addition, no paleontological resources have been discovered in this area of Santa Clara. (No Impact)
4.5.3 Conclusion
Implementation of the proposed project would result in no impact on historic structures and paleontological resources. (No Impact)
With implementation of the identified mitigation measures described above, the proposed project would have a less than significant impact on subsurface prehistoric and historic resources. (Less Than Significant Impact with Mitigation)
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4.6 GREENHOUSE GAS EMISSIONS
4.6.1 Setting
Unlike emissions of criteria and toxic air pollutants, which have local or regional impacts, emissions of Greenhouse Gases (GHGs) have a broader, global impact. Global warming associated with the “greenhouse effect” is a process whereby GHGs accumulating in the atmosphere contribute to an increase in the temperature of the earth’s atmosphere. The principal GHGs contributing to global warming and associated climate change are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated compounds. Emissions of GHGs contributing to global climate change are attributable in large part to human activities associated with the transportation, industrial/ manufacturing, utility, residential, commercial, and agricultural sectors.
4.6.1.1 City of Santa Clara General Plan
The Santa Clara 2010-2035 General Plan includes policies that address the reduction of GHG emissions during the planning horizon of the General Plan. Goals and policies that address sustainability (see Appendix 8.13: Sustainability Goals and Policies Matrix in the General Plan) are aimed at reducing the City’s contribution to GHG emissions. As described below, the development of a comprehensive GHG emissions reduction strategy for the City is also included in the General Plan.
Climate Action Plan
The City of Santa Clara has a comprehensive GHG emissions reduction strategy (Climate Action Plan) to achieve its fair share of statewide emissions reductions for the 2020 timeframe consistent with AB 32, the Global Warming Solutions Act. The Climate Action Plan (CAP) was adopted on December 3, 2013. The City of Santa Clara CAP specifies the strategies and measures to be taken for a number of focus areas (coal-free and large renewables, energy efficiency, water conservation, transportation and land use, waste reduction, etc.) citywide to achieve the overall emission reduction target, and includes an adaptive management process that can incorporate new technology and respond when goals are not being met.
A key reduction measure that is being undertaken by the City of Santa Clara under the CAP is in the Coal-Free and Large Renewables focus area. The City of Santa Clara operates Silicon Valley Power (SVP), a publicly owned utility that provides electricity for the community of Santa Clara, including the project site. Since nearly half (48 percent) of Santa Clara’s GHG emissions result from electricity use, removing GHG-intensive sources of electricity generation (such as coal) is a major focus area in the CAP for achieving the City’s GHG reduction goals. This measure is being undertaken by SVP.
CEQA clearance for all discretionary development proposals are required to address the consistency of individual projects with reduction measures in the CAP and goals and policies in the General Plan designed to reduce GHG emissions. Compliance with appropriate measures in the CAP would ensure an individual project’s consistency with an adopted GHG reduction plan. Projects that are consistent with the CAP would have a less than significant impact related to GHG emissions.
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4.6.1.2 Bay Area Air Quality Management District
BAAQMD is primarily responsible for assuring that the National and State ambient air quality standards are attained and maintained in the Bay Area. BAAQMD is also responsible for adopting and enforcing rules and regulations concerning air pollutant sources, issuing permits for stationary sources of air pollutants, inspecting stationary sources of air pollutants, responding to citizen complaints, monitoring ambient air quality and meteorological conditions, awarding grants to reduce motor vehicle emissions, conducting public education campaigns, as well as many other activities. BAAQMD has jurisdiction over much of the nine-county Bay Area.
The adopted BAAQMD Air Quality CEQA Thresholds of Significance for operational-related GHG 7 emissions is 1,100 metric tons of CO2e per year or 4.6 metric tons of CO2e per service population per year. BAAQMD does not have an adopted threshold of significance for construction-related GHG emissions.
4.6.1.3 Existing Conditions
The project site is a creek segment with no public access and does not generate GHG emissions.
4.6.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Generate greenhouse gas emissions, either 1-3 directly or indirectly, that may have a significant impact on the environment? 2. Conflict with an applicable plan, policy or 1-3 regulation adopted for the purpose of reducing the emissions of greenhouse gases?
4.6.2.1 Greenhouse Gas Emissions Impacts
Operational Emissions
Use of the proposed trail by pedestrians and bicyclists would not generate any pollutant emissions and, as a result, would not increase GHG emissions. Expansion of the trail system would likely result in increased trail usage, which in turn could incrementally reduce traffic trips in the project area, consistent with the City adopted Climate Action Plan. Any decrease in automobile trips associated with the proposed project would be beneficial as it would assist the City and State in achieving established GHG emissions reduction goals. (No Impact)
7 Service population is the sum of projected new residents and full time workers at the project site.
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Construction Emissions
There are no established thresholds of significance for construction GHG emissions. BAAQMD does, however, encourage the analysis of GHG construction emissions when possible.
A small amount of GHG emissions would occur due to the operation of construction equipment and worker trips to and from the site. Construction emissions generated by the project would not be substantial and would be temporary in nature. In addition, the project would incorporate all feasible best management practices to reduce overall GHG emissions during construction. Construction of the proposed trail would not significantly contribute to regional GHG levels and would not impact the State’s ability to meet the GHG emissions reduction goals established by AB 32. (Less Than Significant Impact)
4.6.3 Conclusion
The project would not conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing GHGs. The proposed project would not result in a significant impact from GHG emissions. (Less Than Significant Impact)
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4.7 HAZARDS AND HAZARDOUS MATERIALS
The following discussion is based on an Environmental Site Assessment prepared by AEI Consultants in August 2015.8 A copy of the report is attached in Appendix B of this Initial Study.
4.7.1 Setting
The project site is the portion of Saratoga Creek between Central Park and Homeridge Park in the City of Santa Clara. Based on groundwater monitoring data from the State Water Resources Control Board (SWRCB) Geotracker database, it is estimated that the direction of groundwater flow beneath the project site is northeast and has a depth of 14 to 22 feet below the ground surface.
4.7.1.1 Site History
A land use history of the project area has been compiled based on aerial photographs, Sanborn fire insurance maps, and City directories. Based on a review of these sources, the area was utilized as agricultural land in 1948. There is no specific data for the area prior to 1948. Consistent with the development patterns of Santa Clara, it is assumed that the area was utilized for farm land or was undeveloped prior to 1948. The area around the creek was primarily agricultural land until 1966. The surrounding residential neighborhoods were constructed in the 1960’s and Central Park was constructed in 1967. Kaiser Hospital, which was previous located on Kiely Boulevard (north of the creek), was constructed in 1964. The hospital was demolished in 2009 and the site is now developed with housing.
4.7.1.2 On-Site Sources of Contamination
Due to the historic agricultural operations in the project area, it is possible that residual contamination from pesticides, herbicides, and fertilizers may be found in the soils around the creek.
4.7.1.3 Off-Site Sources of Contamination
Review of available regulatory databases found three listed hazardous waste sites within a quarter- mile of the project site. Off-site sources of contamination could impact the project site through contaminants in the groundwater. Since contaminants tend to dissipate with distance in the soil and groundwater, the primary concern are hazardous source sites in proximity to the project site. The three sites are listed in Table 4.8-1 below.
8 The Environmental Site Assessment (ESA) referenced in this analysis was prepared for the City of Santa Clara’s proposed International Swim Center/Community Recreation Center project in Central Park. Due to the breadth of the scope of the ESA, the data provided is sufficient to assess any potential hazardous materials impacts resulting from the proposed project.
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Table 4.7-1: Hazardous Materials Sites Within ¼ Mile of the Project Site
Business Name and Database Listing Site Description Site Address RCRA GEN, Kaiser Hospital Generated small quantities of hazardous waste FINDS/FRS (former) including barium, mercury, ignitable waste, 900 Kiely Boulevard corrosive waste, reactive waste, benzenebutanoic acid, solver, lead, spent halogenated and non- halogenated solvents, and chromium. There are no documented releases from this facility.
The facility has since been demolished and the site redeveloped with residential land uses. LUST Chevron #9-4300 Gasoline, BTEX, and fuel oxygenates contaminated 2790 Homestead Road a drinking water aquifer. Groundwater monitoring wells were installed in 1986 and three gasoline underground storage tanks (USTs) and one waste oil UST were removed from the site prior to redevelopment in 1987.
Status: Case Closed (2009) LUST Arco #2153 Gasoline and benzene contaminated the 2800 Homestead Road groundwater (not a drinking water source). Groundwater monitoring wells were installed in 1988 during the UST replacement investigation.
Status: Case Closed (2004)
4.8.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Create a significant hazard to the public or 1-3, 8 the environment through the routine transport, use, or disposal of hazardous materials? 2. Create a significant hazard to the public or the 1-3, 8 environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment?
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Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 3. Emit hazardous emissions or handle 1-3, 8 hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? 4. Be located on a site which is included on a list 1-3, 8 of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, will it create a significant hazard to the public or the environment? 5. For a project located within an airport land 1-3, 8 use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, will the project result in a safety hazard for people residing or working in the project area? 6. For a project within the vicinity of a private 1-3, 8 airstrip, will the project result in a safety hazard for people residing or working in the project area? 7. Impair implementation of, or physically 1-3, 8 interfere with, an adopted emergency response plan or emergency evacuation plan? 8. Expose people or structures to a significant 1-3, 8 risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands?
4.7.2.1 On-Site Hazardous Materials Impacts
Soil and Groundwater Contamination
A discussed in Section 4.7.1.2, there are no regulatory agency records or evidence of hazardous materials usage immediately adjacent to the creek. The project area was, however, used as agricultural land until approximately 1967 when the area was developed with the existing parks and residential neighborhoods. Because of the past agricultural uses, it is reasonable to assume that pesticides and other agricultural chemicals were used as part of the normal agricultural operations. It is common to find arsenic, lead, and dichlorodiphenyltrichloroethane (DDT) residue in the soils in Santa Clara County from historic farming operations.
Development of the proposed project would require excavation for the trail installation and trenching to reroute utility lines which could result in impacts to construction workers from exposure to soil contamination related to historic agricultural operations.
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Impact HAZ-1: Implementation of the proposed project could expose construction workers to contaminated soil. (Significant Impact)
Mitigation and Avoidance Measures
The project proposes to implement the following mitigation measures:
MM HAZ-1.1: Prior to excavation, shallow soil samples shall be taken along the proposed trail alignment and other areas of disturbance outside the creek channel to determine if contaminated soil from previous agricultural land uses is located on-site with concentrations above established construction/trench worker thresholds. The soil sampling plan must be reviewed and approved by the Santa Clara Fire Chief prior to initiation of work.
MM HAZ-1.2: Once the soil sampling analysis is complete, a report of the findings will be provided to the Santa Clara Fire Chief, Director of Planning and Inspection, and other applicable City staff for review. If no contaminates are found above established thresholds, no further action is required.
MM HAZ-1.3: If contaminated soils are found in concentrations above established thresholds a Site Management Plan (SMP) will be prepared and implemented (as outlined below) and any contaminated soils found in concentrations above established thresholds shall be removed and disposed of according to California Hazardous Waste Regulations. The contaminated soil removed from the site shall be hauled off-site and disposed of at a licensed hazardous materials disposal site.
A SMP will be prepared to establish management practices for handling impacted soil material that may be encountered during site development and soil-disturbing activities. Components of the SMP will include: a detailed discussion of the site background; preparation of a Health and Safety Plan by an industrial hygienist; notification procedures if previously undiscovered significantly impacted soil or free fuel product is encountered during construction; on-site soil reuse guidelines based on the California Regional Water Quality Control Board, San Francisco Bay Region’s reuse policy; sampling and laboratory analyses of excess soil requiring disposal at an appropriate off-site waste disposal facility; soil stockpiling protocols; and protocols to manage ground water that may be encountered during trenching and/or subsurface excavation activities. Prior to issuance of grading permits, a copy of the SMP must be approved by the City’s Director of Planning and Inspection, and the Santa Clara Fire Chief.
Future Operations
Operation of the proposed trail would not include the use and storage of hazardous materials. (No Impact)
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4.7.2.2 Off-Site Hazards
Soil and Groundwater Contamination
Based on a review of available regulatory databases, none of the identified off-site sources of contamination pose a significant hazardous materials threat to the project site. While the two LUST sites are up-gradient of the project site, the sites have been remediated and granted case closure status. The former Kaiser Hospital did not have any documented releases and the site has since been developed with housing. Any contamination that may have been found on the hospital site would have been remediated prior to construction of the new housing development. (Less Than Significant Impact)
4.7.2.3 Other Hazards
The project site is not located near any public airport or private air strip. The nearest airport is the San José International Airport, approximately 2.8 miles east of the creek segment. Therefore, implementation of the proposed project would not result in safety hazard impacts due to airport activities. (No Impact)
The project site is located within one-quarter mile of three schools, but would not use or store hazardous materials. As a result, implementation of the proposed project would not result in a hazardous materials impact to schools in the project area. (No Impact)
The project site is in a highly developed urban area and it is not adjacent to any wildland areas that would be susceptible to fire. Therefore, the proposed project would not expose the proposed building and future site users to wildland fires. (No Impact)
The City has evaluated the proposed project design and operations and determined that the project would not interfere with any adopted emergency response plan or emergency evacuation plan. (No Impact)
4.7.3 Conclusion
With implementation of the proposed mitigations, the project would not result in significant impacts related to hazardous materials. (Less Than Significant Impact with Mitigation)
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4.8 HYDROLOGY AND WATER QUALITY
The following analysis is based in part on a Hydraulic Analysis completed by Schaaf & Wheeler in June, 2016. A copy of the report is provided in Appendix C.
4.8.1 Setting
4.8.1.1 Flooding
The project site is designated as a 100-year flood hazard area. According to the Federal Emergency Management Agency (FEMA), the project site is located in Zone A which is an area with an annual one percent chance of flood with floodwaters contained within the channel.9
4.8.1.2 Dam Failure
Based on the Santa Clara Valley Water District dam failure inundation hazard maps, the creek segment is located outside the Lexington Reservoir and Andersen Dam failure inundation hazard 10 11 zones.20F
4.8.1.3 Seiches, Tsunamis, and Mudflows
The creek is not landlocked and would not generate a seiche12. The creek segment is located too far 13 from San Francisco Bay to be affected by a tsunami.21F The project area is flat and there are no mountains or hills near the site that would affect the creek segment in the event of a mudflow.
4.8.1.4 Water Quality Regulatory Setting
The water quality of Saratoga Creek is directly affected by pollutants contained in stormwater runoff from a variety of urban and non-urban uses. Stormwater from urban uses contains metals, pesticides, herbicides, and other contaminants, including oil, grease, asbestos, lead, and animal wastes. Based on data from the California Environmental Protection Agency (CalEPA),14 Saratoga Creek is currently listed on the California 303(d) list15 for exceeding the Total Daily Maximum load (TMDL) for Diazinon and trash.16
9 Federal Emergency Management Agency. Map 06085C0228H. May 18, 2009.
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Nonpoint Source Pollution Program
The Federal Clean Water Act and California’s Porter-Cologne Water Quality Control Act are the primary laws related to water quality. Regulations set forth by the U.S. Environmental Protection Agency (EPA) and the State Water Resources Control Board (SWRCB) have been developed to fulfill the requirements of this legislation. EPA’s regulations include the National Pollutant Discharge Elimination System (NPDES) permit program, which controls sources that discharge pollutants into the waters of the United States (e.g., streams, lakes, bays, etc.). These regulations are implemented at the regional level by the water quality control boards, which for the Santa Clara area is the San Francisco Regional Water Quality Control Board (RWQCB).
Statewide Construction General Permit
The SWRCB has implemented a NPDES General Construction Permit for the State of California. For projects disturbing one acre or more of soil, a Notice of Intent (NOI) and Storm Water Pollution Prevention Plan (SWPPP) must be prepared prior to commencement of construction.
Municipal Regional Stormwater NPDES Permit (MRP)/C.3 Requirement
The San Francisco Bay RWQCB also has issued a Municipal Regional Stormwater NPDES Permit (Permit Number CAS612008) (MRP). In an effort to standardize stormwater management requirements throughout the region, this permit replaces the formerly separate countywide municipal stormwater permits with a regional permit for 77 Bay Area municipalities, including the City of Santa Clara. Under provisions of the NPDES Municipal Permit, redevelopment projects that disturb more than 10,000 square feet are required to design and construct stormwater treatment controls to treat post-construction stormwater runoff. Amendments to the MRP require all of the post- construction runoff to be treated by using Low Impact Development (LID) treatment controls, such as biotreatment facilities. The Santa Clara Valley Urban Runoff Pollution Prevention Program (SCVURPPP) assists co-permittees, such as the City of Santa Clara, with implementing the provisions of the Municipal NPDES Permit.
Hydromodification
In addition to water quality controls, the Municipal Regional Stormwater NPDES permit requires all new and redevelopment projects that create or replace one acre or more of impervious surface to manage development-related increases in peak runoff flow, volume, and duration, where such hydromodification is likely to cause increased erosion, silt pollutant generation or other impacts to beneficial uses of local rivers, streams, and creeks. Projects may be deemed exempt from the permit requirements if they do not meet the size threshold, drain into tidally influenced areas or directly into the Bay, drain into hardened channels, or are infill projects in subwatersheds or catchments areas that are greater than or equal to 65 percent impervious (per the Santa Clara Permittees Hydromodification Management Applicability Map).
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Based on the SCVUPPP Watershed Map for the City of Santa Clara, the project site is within a subwatershed that drains into a hardened channel or tidal area. As a result, the project is not subject 17 to the NPDES hydromodification peak runoff requirements. 25F
4.8.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Violate any water quality standards or waste 1-3 discharge requirements? 2. Substantially deplete groundwater supplies or 1-3 interfere substantially with groundwater recharge such that there will be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre-existing nearby wells will drop to a level which will not support existing land uses or planned uses for which permits have been granted)? 3. Substantially alter the existing drainage 1-3, 12 pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which will result in substantial erosion or siltation on-or off-site? 4. Substantially alter the existing drainage 1-3, 12 pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner which will result in flooding on-or off-site? 5. Create or contribute runoff water which will 1-3 exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff? 6. Otherwise substantially degrade water 1-3 quality? 7. Place housing within a 100-year flood hazard 1-3, 13 area as mapped on a Federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map?
17 Santa Clara Valley Urban Runoff Pollution Prevention Program. http://www.scvurppp-w2k.com/hmp_maps.htm Accessed September 9, 2015.
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Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 8. Place within a 100-year flood hazard area 1-3, 13 structures which will impede or redirect flood flows? 9. Expose people or structures to a significant 1-3, 10, risk of loss, injury or death involving 13 flooding, including flooding as a result of the failure of a levee or dam? 10. Inundation by seiche, tsunami, or mudflow? 1-3, 11
4.8.2.1 Flooding and Channel Capacity
The proposed project would place a bicycle/pedestrian trail in a designated flood zone; no housing or other structures are proposed. The trail and access ramps would be located within the flood channel, but would be installed on existing maintenance roads and/or within excavated areas.
A hydraulic analysis was undertaken to determine the effect of the project on the water surface elevation level (WSEL) during a 100-Year Storm. The analysis, a copy of which is found in Appendix C of this Initial Study, determined that a majority of the cross sections within the project limits exhibit either no impact or a decrease in WSEL’s due to the project. There are some locations downstream of both Homestead Road and Kiely Boulevard that do show an increase in WSEL. These increases are typically on the order of 0.3 feet or less. None of the increases in WSEL would increase or induce flooding in the overbanks, which is consistent with the SCVWD’s design goals. The increase is typically caused by a slowing of the channel velocity due to increases in cross sectional area and wetted perimeter. Since the energy grade line is not significantly changing from existing conditions due to the project, the decrease in channel velocity correlates to an increase in WSEL. (Less Than Significant Impact)
The project would not permanently place people or structures in a flood or dam inundation zone and would not expose people to significant risk of loss, injury, or death due to flooding. The proposed project would have a no flooding impact. (No Impact)
4.8.2.2 Water Quality Impacts
Construction Impacts
Implementation of the proposed project will require grading and excavation of the site, which could increase erosion and sedimentation that could accumulate in Saratoga Creek. Because the project will disturb more than one acre of land, the project would be required to comply with the general stormwater permit and prepare a SWPPP for construction activities.
In addition, per City requirements, the following measures (based on RWQCB recommendations) have been included in the project as a condition of project approval to reduce potential construction- related water quality impacts:
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Construction Measures
Burlap bags filled with drain rock will be installed around storm drains to route sediment and other debris away from the drains. Earthmoving or other dust-producing activities would be suspended during periods of high winds. All exposed or disturbed soil surfaces would be watered at least twice daily to control dust as necessary. Stockpiles of soil or other materials that can be blown by the wind would be watered or covered. All trucks hauling soil, sand, and other loose materials would be covered and all trucks would be required to maintain at least two feet of freeboard. All paved access roads, parking areas, staging areas and residential streets adjacent to the construction sites would be swept daily (with water sweepers). Vegetation in disturbed areas would be replanted as quickly as possible. All work in the streambed will be restricted to the dry season (April 15 – October 15), which may be temporarily extended each year with written RWQCB permission if the stream bed is dry prior to April 15 or after October 15. To the maximum extent practicable, all grading within 100 ft of riparian habitat will occur during the dry season (15 April – 15 October). If grading is to occur during the rainy season or late-season rain events occur during construction the primary BMPs selected will focus on erosion control. End-of-pipe sediment control measures (e.g., basins and traps) will be used only as secondary measures. Any temporary fills to be used during dry season streambed access will be materials that allow for complete and total temporary fill removal prior to exiting the channel at the end of the dry season. This requires that fine materials such sands and soils would be bagged or contained in such a way that they may be entirely removed. No equipment will be operated in the live channel during the wet season. Silt fencing will be installed between any activities conducted within 100 ft of the top-of- bank and the edge of the streams to prevent dirt or other materials from entering the channel. Environmentally Sensitive Area fencing will be installed where work is to occur adjacent to riparian habitats further than 100 ft from the stream crossings. No debris, soil, silt, sand, bark, slash, sawdust, cement, concrete, washings, petroleum products or other organic or earthen material will be allowed to enter into or be placed where it may be washed by rainfall or runoff into aquatic habitat. During construction activities, equipment maintenance and refueling areas shall be located at least 60 ft from any aquatic habitat. Conduct refueling behind a contaminant barrier that prevents spilled or leaked fuel from entering any drainage. All equipment servicing will be conducted with designated areas with appropriate setbacks from the top-of-bank. All motorized equipment used during construction will be checked for oil, fuel, and coolant leaks prior to initiating work. All vehicles and equipment will be kept clean. Excessive build-up of oil and grease will be prevented. Maintenance, repairs, or other necessary actions will be taken to prevent or repair leaks, prior to use on the site.
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Incoming vehicles and equipment (including delivery trucks, and employee and subcontractor vehicles) will be checked for leaking oil and fluids. Vehicles or equipment visibly leaking operational fluids will not be allowed onsite. The construction site manager will prevent the accidental release of chemicals, fuels, lubricants, and non-storm drainage water into channels following these measures: o All construction personnel will be appropriately trained in spill prevention, hazardous material control, and cleanup of accidental spills. o Equipment and materials for cleanup of spills will be available on site and spills and leaks will be cleaned up immediately and disposed of according to applicable regulatory requirements. o The construction site manager will ensure that hazardous materials are properly handled and natural resources are protected by all reasonable means.
Spill prevention kits will always be in close proximity when using hazardous materials (e.g., at crew trucks and other logical locations). All construction personnel will be advised of these locations. The construction site manager will routinely inspect the worksite to verify that spill prevention and response measures are properly implemented and maintained. Prior to the start of construction activities within or near Saratoga Creek, the limits of the construction zone will be clearly marked and fenced (under the supervision of a qualified biologist and/or qualified ecological monitor) to protect vegetation outside of the established construction zone. An ecological monitor will make regular site inspections to ensure that the fence remains in place and that construction activities are confined to the delineated impact areas. Areas of temporary, construction-related impacts will be restored in accordance with a Project Erosion Control Plan. The Erosion Control Plan will include components for erosion control, such as designating areas of disturbance, designating restricted-entry zones, diverting runoff away from disturbed areas, and providing for revegetation. The Erosion Control Plan will also include seeding with a native erosion control seed mix at the fill prism and other associated Project disturbances where vegetation has been disturbed. These seed mixtures used for revegetation of the impacted habitats will not contain invasive non-native species but will be composed of native or sterile non-native species. If sterile non-native mixtures must be used for temporary erosion control, native seed mixtures will be used in subsequent treatments to provide long-term erosion control and prevent colonization by invasive non-native species.
With implementation of the identified construction measures and compliance with the NPDES General Construction Permit, construction of the proposed project would have a less than significant impact on water quality. (Less Than Significant Impact)
Post-Construction Impacts
Implementation of the proposed project would result in an increase in impervious surfaces along the project alignment. Specifically, the paved trail and access ramps would add approximately 31,630 square feet of impervious surface area within the creek channel.18 Increases in impervious surfaces reduce areas available for infiltration of stormwater into the ground and, therefore, result in an increase in stormwater runoff. Increases in runoff, in turn, have the potential to degrade water
18 Personal Communication – Joe Streeper, Mark Thomas & Company. March 2, 2016.
Saratoga Creek Trail Initial Study City of Santa Clara 54 June 2016 quality by causing erosion or siltation. In addition, stormwater runoff frequently contains pollutants from a variety of sources.
To address the above-described effects, and in accordance with the Municipal Regional NPDES permit, impervious trails that are greater than 10 feet wide or are within 50 feet of the top of bank of any creek are required to comply with Provision C.3 of the permit. While the proposed trail would be a minimum of 10 feet wide, the Municipal Regional NPDES permit identifies specific exclusions to Provisions C.3.b.ii.(4)(a)-(c). Specifically, impervious trails built to direct stormwater runoff to adjacent vegetated areas, or other non-erodible permeable areas, preferably away from creeks or towards the outboard side of levees are exempt from the Municipal Regional NPDES permit.
As proposed, the trail would generally be sloped approximately 1.5 percent to allow stormwater runoff to flow from the impervious surfaces of the trail to vegetated areas. For the pedestrian bridge adjacent to Kiely Boulevard, stormwater would collect on the composite concrete deck and flow to the concrete abutments. The areas surrounding the abutments would be permeable and planted with vegetation which would filter any water not readily absorbed. As a result, the project would have a less than significant operational stormwater impact. (Less Than Significant Impact)
4.8.3 Conclusion
The project would not be subject to inundation by seiche, tsunami, or mudflow. (No Impact)
The project would not significantly diminish the capacity of the creek channel to effectively carry flood flows. (Less Than Significant Impact)
The project would comply with the Nonpoint Source Pollution Program and the Municipal Regional Stormwater Permit, and therefore would not violate any water quality standards or waste discharge requirements. (Less Than Significant Impact)
While construction activities could temporarily increase pollutants loads in stormwater runoff, implementation of the identified construction measures would reduce construction-related impacts to water. (Less Than Significant Impact)
Saratoga Creek Trail Initial Study City of Santa Clara 55 June 2016
4.9 LAND USE
4.9.1 Setting
The City of Santa Clara Parks & Recreation Department (Department) is responsible for maintaining and programming the various parks and recreation facilities, and works cooperatively with public agencies in coordinating all recreational activities within the City. Overall, the Department maintains and operates Central Park (52 acres), 25 neighborhood parks (122.67 acres), five mini parks (2.59 acres), public open space (16.13 acres of improved area and 40.08 acres of unimproved area for a total of 56.21 acres), recreation facilities (approximately 14.9 acres, excluding the Santa Clara Golf and Tennis Club and the Santa Clara Police Activities League Bicycle Motocross, recreation trails (3.7 acres), and joint use facilities (47.5 acres) throughout the City, totaling approximately 252.5 improved acres. Community parks are over 15 acres, neighborhood parks are one to fifteen acres and mini parks are typically less than one acre in size.
The proposed trail alignment is located within the existing Saratoga Creek channel, which is an engineered channel with dense riparian vegetation. The northernmost point of the project creek segment is located within Central Park. The creek segment is located along the southern boundary of the park, adjacent to a surface parking lot. On the park side, the creek channel is adjacent to a maintenance road, mature trees and grassland. A school is located immediately east of the parking lot and an apartment complex is located to the south.
Currently, the area west of Saratoga Creek contains group and individual picnic facilities, playgrounds, restroom facilities, an amphitheater, two lighted tennis courts, basketball courts, the Veterans Memorial, and a Community Recreation Center. East of the creek is the George F. Haines International Swim Center, Bob Fatio Sports Center (including Tony Sanchez Field and a second lighted softball field), the Santa Clara Tennis Center with eight lighted tennis courts and a practice wall, open space, a lake, large group picnic areas, restroom facilities, a lawn bowling green, and exercise course, and the Central Park Library.
The southernmost point of the project creek segment is located within Homeridge Park, a six-acre park with a children’s play area, basketball court, picnic facilities, and restroom facilities. In this location, the creek segment is adjacent to a two-story apartment complex and a single-family house. The house has a minimal setback from the riparian corridor. A surface parking area for the apartment complex abuts the creek channel.
Between Central Park and Homeridge Park, the creek channel is surrounded by single-family houses, townhouses, an electrical sub-station, a small retail center, and the staging area for the residential development on the Kaiser site. The creek is separated from the surrounding land uses by wood, chain link and concrete fences.
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4.9.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project: 1. Physically divide an established community? 1-3 2. Conflict with any applicable land use plan, 1-3 policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? 3. Conflict with any applicable habitat 1-3 conservation plan or natural community conservation plan?
4.9.1.2 Land Use Impacts
The proposed project would result in a bicycle/pedestrian trail being constructed within a segment of the Saratoga Creek channel. The trail would extend pedestrian and bicycle access along Saratoga Creek and connect the surrounding residential neighborhoods to Central Park and Homeridge Park, enhancing the alternative transportation network in the City of Santa Clara. The trail would be within the existing creek channel and would not impact any adjacent land uses.
Due to the nature and location of the proposed project, the project would not physically divide an established community, would not conflict with any applicable land use policies, and would not conflict with any applicable habitat conservation plan or natural community conservation plan. (No Impact)
4.9.3 Conclusion
Implementation of the proposed project would not result in any land use impacts. (No Impact)
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4.10 NOISE
4.10.1 Setting
4.10.1.1 Background Information
Acceptable levels of noise vary from land use to land use. In any one location, the noise level will vary over time, from the lowest background or ambient noise level to temporary increases caused by traffic or other sources. State and Federal standards have been established as guidelines for determining the compatibility of a particular land use with its noise environment.
There are several methods of characterizing sound. The most common in California is the A- 19 weighted sound level or dBA.30F This scale gives greater weight to the frequencies of sound to which the human ear is most sensitive. Because sound levels can vary markedly over a short period of time, a method for describing either the average character of the sound or the statistical behavior of the variations must be utilized. Most commonly, environmental sounds are described in terms of an average level that has the same acoustical energy as the summation of all the time-varying events. This energy-equivalent sound/noise descriptor is called Leq. The most common averaging period is hourly, but Leq can describe any series of noise events of arbitrary duration.
Although the A-weighted noise level may adequately indicate the level of environmental noise at any instant in time, community noise levels vary continuously. Most environmental noise includes a conglomeration of noise from distant sources which create a relatively steady background noise in which no particular source is identifiable. To describe the time-varying character of environmental noise, the statistical noise descriptors, L01, L10, L50, and L90, are commonly used. They are the A- weighted noise levels equaled or exceeded during 1, 10, 50, and 90 percent of a stated time period.
Sound level meters can accurately measure environmental noise levels to within about plus or minus one dBA. Since the sensitivity to noise increases during the evening hours, 24-hour descriptors have been developed that incorporate artificial noise penalties added to quiet-time noise events. The Day/Night Average Sound Level, Ldn, is the average A-weighted noise level during a 24-hour day, obtained after the addition of 10 dB to noise levels measured in the nighttime between 10:00 PM and 7:00 AM. The Community Noise Equivalent Level, CNEL, is the average A-weighted noise level during a 24-hour day, obtained after the addition of 5 dB to noise levels measured in the evening between 7:00 PM and 10:00 pm and after the addition of 10 dB to noise levels measured in the nighttime between 10:00 PM and 7:00 AM. Thus, the CNEL descriptor is slightly more conservative than the Ldn descriptor because it includes the penalty for noise occurring during the evening hours.
The most widespread and continual source of noise in Santa Clara is transportation and transportation-related facilities. Freeways, local arterials, the Norman Y. Mineta San José International Airport, railroads, and Light Rail Transit are all major contributors to noise in Santa Clara.
19 The sound pressure level in decibels as measured on a sound level meter using the A-weighting filter network. All sound levels in this discussion are A-weighted, unless otherwise stated.
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4.10.1.2 Regulatory Background – Noise
The State of California and the City of Santa Clara have established guidelines, regulations, and policies designed to limit noise exposure at noise sensitive land uses. Appendix E of the State CEQA Guidelines, the State of California Building Code, and the City of Santa Clara’s Noise Element of the General Plan present the following applicable criteria:
State CEQA Guidelines. CEQA contains guidelines to evaluate the significance of effects resulting from a proposed project. These guidelines have been used in this Initial Study as thresholds for establishing potentially significant noise impacts and are listed under Thresholds of Significance.
City of Santa Clara General Plan. Based on the City’s General Plan Noise Element, Table 4.12-1 shows the noise levels considered compatible with specific land uses. Recreational land uses are considered compatible with Ldn noise levels up to 65 dBA and acceptable with design and insulation techniques in areas with Ldn noise levels up to 75 dBA.
Table 4.12-1: Noise and Land Use Compatibility (Ldn & CNEL) Land Use 50 55 60 65 70 75 80 85 Residential
Educational
Recreational
Commercial
Industrial
Open Space Compatible Require Design and insulation to reduce noise levels Incompatible. Avoid land use except when entirely indoors and an interior noise level of 45 Ldn can be maintained Source: City of Santa Clara 2010-2035 General Plan
4.10.1.3 Existing Noise Environment
Portions of the project site are located adjacent to Kiely Boulevard and Homestead Road. Noise in the project area is generated primarily from vehicular traffic along the adjacent roadways. The City of Santa Clara General Plan shows the existing noise levels along the adjacent roadways at 65 to 75 20 dBA CNEL and the creek segment below 65 dBA CNEL.31F The creek segment is outside the 60-dB CNEL noise contour for the Norman Y. Mineta San José International Airport.
There are noise sensitive land uses (i.e., residences) along the creek segment.
20 City of Santa Clara. 2010. City of Santa Clara 2010-2035 General Plan, Section 5.10.6 Noise Goals and Policies, Figure 5.10-4.
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4.10.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated Would the project result in: 1. Exposure of persons to or generation of noise 1-3 levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? 2. Exposure of persons to, or generation of, 1-3 excessive groundborne vibration or groundborne noise levels? 3. A substantial permanent increase in ambient 1-3 noise levels in the project vicinity above levels existing without the project? 4. A substantial temporary or periodic increase 1-3 in ambient noise levels in the project vicinity above levels existing without the project? 5. For a project located within an airport land 1-3 use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, will the project expose people residing or working in the project area to excessive noise levels? 6. For a project within the vicinity of a private 1-3 airstrip, will the project expose people residing or working in the project area to excessive noise levels?
4.10.2.1 Noise Impacts From the Project
Long-Term Noise Impacts
Implementation of the proposed project would not increase traffic noise levels along any roadway in Santa Clara because no new traffic trips would be generated by the project. Use of the trail by pedestrians and bicyclists would not increase ambient noise levels in the project area. Therefore, the project would not have a long-term noise impact. (No Impact)
Construction Noise and Vibration Impacts
Construction activity would require the use of heavy equipment during grading and construction that would temporarily increase noise levels within the project area. Typical noise levels generated by construction equipment range from 75 to 80 dBA at a distance of 100 feet from the noise source. Construction activities would be most noticeable at the residential land uses located along the boundaries of the creek segment. Construction noise would also be noticeable to persons within the
Saratoga Creek Trail Initial Study City of Santa Clara 60 June 2016 nearby St. Justin Parish Community School, but to a slightly lesser extent due to the distance between the school buildings and the project alignment (i.e., more than 300 feet).
Noise generated during construction has the potential to disturb nearby residents, especially if heavy equipment were to be used during the evening and nighttime hours when homes are occupied and sleep is occurring. However, compliance with City Code requirements for construction (Chapter 9.10, listed below) will reduce impacts from construction activities on the project site.
Construction and demolition activities shall be limited to the period between 7:00 AM and 6:00 PM Monday through Friday and 9:00 AM to 6:00 PM on Saturdays. No construction or demolition activities are permitted on Sundays or holidays.
Construction crews will be required to use available noise suppression devices and properly maintain and muffle internal combustion engine-driven construction equipment.
The City shall designate a disturbance coordinator and post the name and phone number of this person at easy reference points for the surrounding land uses. The disturbance coordinator shall respond to and address all complaints about noise.
Compliance with City Code requirements during construction activities on the project site will result in a less than significant construction noise impact. (Less Than Significant Impact)
Vibration will occur during various construction activities, primarily during the installation of bridge supports and retaining walls. However, since pile driving would not be used and there are no buildings immediately adjacent to the trail, vibration-related impacts are anticipated to be minimal. (Less Than Significant Impact)
4.10.3 Conclusion
Compliance with City Code requirements would reduce temporary construction noise impacts to a less than significant level. (Less Than Significant Impact)
Implementation of the proposed project would have no long-term noise impact. (No Impact)
Saratoga Creek Trail Initial Study City of Santa Clara 61 June 2016
4.11 RECREATION
4.11.1 Setting
The Department is responsible for maintaining and programming the various parks and recreation facilities, and works cooperatively with public agencies in coordinating all recreational activities within the City. Overall, the Department maintains and operates Central Park (52 acres), 25 neighborhood parks (122.67 acres), five mini parks (2.59 acres), public open space (16.13 acres of improved area and 40.08 acres of unimproved area for a total of 56.21 acres), recreation facilities (approximately 14.9 acres, excluding the Santa Clara Golf and Tennis Club and the Santa Clara Police Activities League Bicycle Motocross, recreation trails (3.7 acres), and joint use facilities (47.5 acres) throughout the City, totaling approximately 252.5 improved acres. Community parks are over 15 acres, neighborhood parks are one to fifteen acres and mini parks are typically less than one acre in size.
Central Park is a community park. Currently, the area west of Saratoga Creek contains group and individual picnic facilities, playgrounds, restroom facilities, an amphitheater, two lighted tennis courts, basketball courts, the Veterans Memorial and a Community Recreation Center. East of the creek is the George F. Haines International Swim Center, Bob Fatjo Sports Center (including Tony Sanchez Field as well as a second lighted softball field), the Santa Clara Tennis Center with eight lighted tennis courts and practice wall, open space, a lake, large group picnic areas, restroom facilities, a lawn bowling green, an exercise course, and the Central Park Library. Homeridge Park is a six-acre neighborhood park and contains picnic facilities, a basketball court, a children’s play area, and restroom facilities. The proposed extension of the Saratoga Creek Trail would connect Central Park and Homeridge Park in the City of Santa Clara.
Currently, an existing segment of the Saratoga Creek Trail, which is used by SCVWD maintenance vehicles, runs along the west side of Saratoga Creek through Central Park and ends on the east side of Kiely Boulevard. The existing maintenance road that is located beyond the top of bank on the south side of the creek would be utilized and would require a minor reconfiguration within an existing, City-owned, parking lot located on the west side of Kiely Boulevard. The existing maintenance ramp at Homestead Road would be removed and a new maintenance ramp would be constructed on the north side of Homestead Road.
The proposed project is part of a larger trail alignment referred to as the Saratoga Creek Extension Trail which extends south of Benton Street to the trail’s confluence near Forbes Avenue.
4.11.2 Environmental Checklist and Discussion of Impacts
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated 1. Would the project increase the use of existing 1-3 neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility will occur or be accelerated?
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Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated 2. Does the project include recreational facilities 1-3 or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment?
The proposed project would complete a segment of the planned Saratoga Creek Trail between Central Park and Homeridge Park. The extension would make the use of the entire trail more convenient for pedestrian and bicyclists, which is intended to increase overall usage of the entire trail. Usage of Homestead Park and Central Park would also likely increase due to the improved pedestrian and bicycle access from the surrounding residential areas and between the parks. This effect is consistent with the objective of the project, which is to increase recreational opportunities by providing new and improved facilities in Santa Clara.
The project would expand and enhance the City’s trail facilities and would further the City’s recreational service goals. Increased use of the Saratoga Creek Trail and nearby parks due to the project would not be a detriment because providing additional recreational opportunities is a key project objective. To summarize, the project would result in a beneficial impact to passive recreation facilities in the City of Santa Clara. Therefore, the project’s effect would not be adverse. (No Impact)
4.11.3 Conclusion
Implementation of the proposed project would have no adverse impact on existing recreational facilities. (No Impact)
Saratoga Creek Trail Initial Study City of Santa Clara 63 June 2016
4.12 MANDATORY FINDINGS OF SIGNIFICANCE
Less Than Potentially Significant Less Than Checklist Significant With Significant No Impact Source(s) Impact Mitigation Impact Incorporated 1. Does the project have the potential to degrade 1-13 the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? 2. Does the project have impacts that are 1-13 individually limited, but cumulatively considerable? (“Cumulatively considerable” means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? 3. Does the project have the potential to achieve 1-13 short-term environmental goals to the disadvantage of long-term environmental goals? 4. Does the project have environmental effects 1-13 which will cause substantial adverse effects on human beings, either directly or indirectly?
4.12.1 Findings
4.12.1.1 Natural Environmental and California History
The project would result in a new creek trail, primarily along an existing maintenance road, within an urban area. As discussed in Section 4.4, the project would have temporary construction related biological impacts, as well as permanent impacts to 0.54 acres of riparian habitat. However, permanent impacts would be offset by the creation of replacement habitat and therefore the project would not permanently degrade the quality of the natural environment (i.e., substantially reduce natural habitats or wildlife/fish populations). In addition while there is the potential for subsurface resources to be found on-site, the identified mitigation measures would ensure that the project would not eliminate important artifacts associated with California history or prehistory.
4.12.1.2 Short-Term Environmental Goals vs. Long-term Environmental Goals
The proposed trail would be located within an existing creek channel that has been modified over time (installation of rip-rap and concrete), and which has a riparian corridor comprised of both native
Saratoga Creek Trail Initial Study City of Santa Clara 64 June 2016 and non-native vegetation. While installation of the trail may facilitate alternative modes of transportation through the immediate project area and increase park usage, it would also result in short-term air quality and biological impacts due to construction. The trail would not, however, have a detrimental effect on long-term environmental goals.
4.12.1.3 Cumulative Impacts
Due to the nature of the proposed project, the project would have no measurable effect on agricultural or forest resources, geology and soils, mineral resources, population and housing, public services, transportation, or utilities. Because there would be no measureable effect at the project level, the project would not have a cumulatively considerable impact to these resources areas. The project would also have no impact or a less than significant impact on aesthetics, GHG emissions, hydrology, land use, noise and recreation. In the immediate vicinity of the project site, the City of Santa Clara has proposed construction of a new International Swim Center and community recreation center (ISC/CRC) within Central Park. Due to the size of this project, it is reasonable to assume that it would result in impacts to many of the aforementioned resources area. Nevertheless, the effect of the proposed trail project is minimal and, when combined with the ISC/CRC project, the net effect on these resources areas would not be cumulatively significant. There are no other pending projects in the project area or on the adjacent segments of the creek trail which, when combined with the proposed project, would result in a cumulative impact to these resources area.
The project would result in air quality impacts during construction. Compliance with City Codes and BAAQMD dust control mitigation measures would reduce construction-related impacts to a less than significant level. It is not known if the ISC/CRC project and the trail project would be constructed at the same time. The main site for the ISC/CRC project is located approximately 700 feet north of the trail project, and the combined effects of construction would not be cumulatively significant. The ISC/CRC project does, however, propose a parking structure on the parking lot adjacent to the northernmost portion of the project creek segment. The existing parking lot would be utilized as a staging area for the trail project and, as such, those projects could not occur at the same time. Therefore, because the construction impacts from both projects would be temporary and would be mitigated, and because of the distance between the construction activities, these projects combined would not have a cumulatively significant impact and the proposed project would not have a cumulatively considerable air quality or noise impact.
The impacts to biological resources from the proposed project would be a direct result of construction within the creek channel. The ISC/CRC project does not propose any construction within the creek channel. It is reasonable to assume that the ISC/CRC project would result in the removal of some trees which, when combined with the trail project, would reduce the overall habitat available for nesting or migratory birds in the immediate project area until such time as trees are replanted and grow to sufficient size. The project includes extensive replanting at various mitigation sites to mitigate for the loss of trees. The ISC/CRC project would also be required to mitigation for the loss of trees consistent with the City’s tree replacement policy.
The cumulative effect of these projects on trees within the park and along the creek trail would be localized. There would still be abundant trees within the riparian corridor on the adjacent creek segments, in the undisturbed areas of the park, and within the greater project area. Further, the 94 trees to be impacted by the project will be mitigated by the planting of up to 306 replacement trees,
Saratoga Creek Trail Initial Study City of Santa Clara 65 June 2016 resulting in no net loss of trees. As such, the overall loss of trees would not be cumulatively significant and the proposed project would not have a cumulatively considerable impact on biological resources in the project area.
Because there is documentation indicating that Central Park is an approximate location of archaeological resources and the project would be within a creek channel, the project site has the potential for buried historic and/or prehistoric resources. If there are resources found during construction of the trail, those resources would likely be archaeologically linked to any artifacts found during construction of the ISC/CRC project. Both projects would be required to mitigate impacts to subsurface resources consistent with State law and local regulations. As the City is the applicant for both projects, artifacts found on either site would be recorded, collected, and curated using the same methodology and patterns of occupation and use would likely be more apparent, creating a greater understanding of the history and/or prehistory of this area. Therefore, the overall net effect of these projects on cultural resources would not be cumulatively significant and the proposed project would not have a cumulatively considerable impact on cultural resources in the project area.
Due to the historic agricultural operations in the project area, it is possible that residual contamination from pesticides, herbicides, and fertilizers may be found in the soils around the creek. As a result, construction workers may be exposed to contamination in the soils. This impact is very localized and mitigation measures are proposed to reduce this impact to less than significant. The main construction site for the ISC/CRC project is located approximately 700 feet north of the trail project, and the combined effects of exposure to contaminated soils would not be cumulatively significant and the proposed project would not have a cumulatively considerable hazardous materials impact.
4.12.1.4 Direct or Indirect Adverse Effects on Human Beings
As discussed in the respective sections, the proposed project would have no impact or a less than significant impact on aesthetics, agricultural and forest resources, geology and soils, GHG emissions, hydrology and water quality, land use, mineral resources, noise, population and housing, public services, recreation, transportation, and utility and service facilities.
Air quality and hazardous materials impacts related to construction would be temporary and reduced to a less than significant level. Biological impacts would be fully mitigated so that there would be no net loss of sensitive habitat. Cultural resources impacts would also be reduced to less than significant with implementation of the identified mitigation measures. As a result, the project would have not have substantial adverse effect on humans.
4.12.2 Conclusion
Implementation of the proposed project would not result in any significant unavoidable impacts, impacts that are cumulatively considerable, or directly or indirectly cause substantial adverse effects on human beings. (Less Than Significant Impact)
Saratoga Creek Trail Initial Study City of Santa Clara 66 June 2016
Checklist Sources
1. CEQA Guidelines - Environmental Thresholds (professional judgment and expertise and review of project plans). 2. City of Santa Clara. Santa Clara General Plan and City Code. 3. City of Santa Clara. General Plan EIR. 4. Bay Area Air Quality Management District. CEQA Guidelines. June 2010 5. Bay Area Air Quality Management District. Annual Bay Area Air Quality Summaries. 2009. 6. H.T. Harvey & Associates. Biological Resources Report. June 2016. 7. Holman and Associates. Archaeological Literature Search. January 2015. 8. City of Santa Clara. Santa Clara 2010 Climate Action Plan. September 2013. 9. AEI Consultants. Phase I Environmental Site Assessment. August 2015. 10. Santa Clara Valley Water District. Flood Inundation Maps. 2009. 11. Association of Bay Area Governments (ABAG). Tsunami Inundation Emergency Planning Map for the San Francisco Bay Region. 2009 12. Schaaf & Wheeler. Draft Saratoga Creek Trail Hydraulic Analysis. June 2016. 13. FEMA. Flood Insurance Rate Maps.
Saratoga Creek Trail Initial Study City of Santa Clara 67 June 2016
SECTION 5.0 REFERENCES
Association of Bay Area Governments. Tsunami Inundation Emergency Planning Map for the San Francisco Bay Region.
Bay Area Air Quality Management District. Annual Bay Area Air Quality Summaries.
Bay Area Air Quality Management District. CEQA Guidelines. June 2010. < http://www.baaqmd.gov/Divisions/Planning-and-Research/CEQA-GUIDELINES/Updated- CEQA-Guidelines.aspx>
City of Santa Clara. City of Santa Clara 2010-2035 General Plan Integrated Final Environmental Impact Report. 2010.
City of Santa Clara. Santa Clara City Code. Web Site. http://www.codepublishing.com/ca/santaclara/
City of Santa Clara. Santa Clara 2010-2035 General Plan. 2010.
City of Santa Clara. Smart Permit Information System.
Federal Emergency Management Agency. Flood Maps.
Holman & Associates. Archaeological Literature Review for the International Swim Center. January 2015.
H.T. Harvey & Associates. Saratoga Creek Undercrossings, Bridge and Trail Extension Project – Biological Resources Report. June 2016.
IPCC, 2007, Summary for Policymakers, In “Climate Change 2007: The Physical Science Bases. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change” [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. Available at: http://ipcc.ch/
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Saratoga Creek Trail Initial Study City of Santa Clara 68 June 2016
Santa Clara Valley Water District. Lexington Reservoir 2009 Flood Inundation Maps. 2009. http://www.valleywater.org/Services/LexingtonReservoirAndLenihanDam.aspx
State of California Energy Commission. 2009 California Climate Adaptation Strategy Discussion Draft. Frequently Asked Questions. August 3, 2009. Schaaf & Wheeler. Draft Saratoga Creek Trail Hydraulic Analysis. June, 2016. U.S. Environmental Protection Agency. California 303(d) Listed Waters. http://ofmpub.epa.gov/waters10/attains_impaired_waters.impaired_waters_list?p_state=CA&p _cycle=2010 Saratoga Creek Trail Initial Study City of Santa Clara 69 June 2016 SECTION 6.0 AUTHORS AND CONSULTANTS Lead Agency City of Santa Clara Public Works Department Dennis Ng, Acting Assistant Director Falguni Amin, Principal Engineer – Design Division Vincent Luchessi, Senior Civil Engineer Consultants David J. Powers & Associates, Inc. Environmental Consultants and Planners San José, CA John Hesler, Principal Shannon George, Senior Project Manager Zach Dill, Graphic Artist H.T. Harvey & Associates Biological Consultant Los Gatos, CA Saratoga Creek Trail Initial Study City of Santa Clara 70 June 2016