93330 - BOS-2019-1 - RESOLUTION-CEQA Findings and Adopting Mitigated Negative Declaration for Foothill project

RESOLUTION NO RESOLUTION OF THE BOARD OF SUPERVISORS OF THE COUNTY OF SANTA CLARA ADOPTING A MITIGATED NEGATIVE DECLARATION AND MITIGATION MONITORING AND REPORTING PROGRAM AND MAKING RELATED FINDINGS IN ACCORDANCE yITH THE CALIFORNIA ENVIRONMENTAL QUALITY ACT ("CEQA') RELATING TO THE FOOTHILL EXPRESSWAY OPERATIONAL IMPROVEMENT PROJECT
("PROJECT")

WHEREAS, the County desires to provide operational improvements on Foothill Expressway frorn El Monte Avenue to San Antonio Road. This Project will provide auxiliary lanes in each direction of the expressway and improvements at the intersections of Foothill Expressway/El Monte Avenue and Foothill Expressway/San Antonio Road;

WHEREAS, pursuant to CEQA and Initial Study / Mitigated Negative Declaration
(collectively, "Mitigated Negative Declaration") attached hereto as Exhibit A, and a Mitigation Monitoring and Reporting Program ("MMRP") attached hereto as Exhibit B, were prepared for the Project; and

WHEREAS, at its regular meeting of January 15,2019, the Board of Supervisors conducted a public meeting and considered the Mitigated Negative Declaration and MMRP prepared for the Project. NOW, THEREFORE, BE IT RESOLVED by the Board of Supervisors of the County of Santa Clara, State of California, that the Board of Supervisors makes the following findings in accordance with CEQA based upon substantial evidence in the record:
A. The Mitigated Negative Declaration was prepared in accordance with all legal requirements, including all public notice and comment period requirements; and B. The Board has reviewed and considered the Mitigated Negative Declaration and all comments received within the public comment period, as well as written and oral comments received after the public comment period and prior to the adoption of this Resolution, and finds that the document reflects the County's independent judgment and analysis; and C. There is no substantial evidence in the record that the Project, as mitigated, will have a significant effect on the environment. The Mitigated Negative Declaration identified potential impacts to biological resources, cultural resources, andhazardous materials. As discussed in the Mitigated Negative Declaration, mitigation measures have been incorporated into the Project to avoid or reduce these impacts to less-than-significant levels. To mitigate potential impacts to raptor species associated with removal of Resolution Adopting Mitigated Negative Declaration and Mitigation Monitoring Program for Foothill Expressway ProjectPage 1 of3 trees, preconstruction surveys will be conducted by a qualified ornithologist before construction. D. A MMRP has been prepared for the Project to ensure that all mitigation measures will be implemented. All mitigation measures included in the MMRP will be implemented by the County and its contractors; and E. The Clerk of the Board and the County Roads and Airports Department are collectively designated as the location and custodian of the documents and other material constituting the record of proceedings upon which this decision is based Resolution Adopting Mitigated Negative Declaration and Mitigation Monitoring Program for Foothill Expressway ProjectPage 2 of3 NOW, THEREFORE, BE IT FURTHER RESOLVED by the Board of Supervisors of the County of Santa Clara that the Mitigated Negative Declaration, Exhibit A, and MMRP, Exhibit B, for the Foothill Expressway Operational Improvements Project are hereby adopted. PASSED AND ADOPTED by the Board of Supervisors of the County of Santa Clara, State of California on _,2019 by the following vote:
AYES:
NOES:
ABSENT:
ABSTAIN:
S. Joseph Simitian, President Board of Supervisors Signed and certified that a copy of this document has been delivered by electronic or other means to the President, Board of Supervisors. ATTEST:
Megan Doyle Clerk of the Board of Supervisors APPROVED AS TO FORM AND LEGALITY:
Christopher R. Cheleden Lead Deputy County Counsel Attachments to this Resolution:
Exhibit A - Mitigated Negative Declaration Exhibit B - Mitigation Monitoring and Reporting Program Resolution Adopting Mitigated Negative Declaration and Mitigation Monitoring Program for Foothill Expressway ProjectPage 3 of3 Initial Study Foothill Expressway Operational ImprovementsPrepared for In Consultation with September 2018 Foothill Expressway Operational Improvements 1 Mitigated Negative Declaration County of Santa Clara September 2018 County of Santa Clara Roads and Airports Department 1 Skyport Drive, San José, CA 95110 Phone: 408- 573-2488 Fax: 408- 441-0276 www.CountyRoads.org M ITIGATED NEGATIVE DECLARATION The County of Santa Clara Roads and Airports Department  (County) has reviewed the proposed project described below and determined it would not have a significant effect on the environment. “Significant effect on the environment” means a subst antial, or potentially substantial, adverse change in any of the physical conditions within the area affected by the project including land, air, water, flora, fauna, traffic, and ambient noise. NAME OF PROJECT:  Foothill Expressway Operational Improveme nts Project PROJECT LOCATION:  The 0.25-mile se gment of Foothill Expressway located between San Antonio Road and El Monte Avenue in the City of Los Altos. PROJECT DESCRIPTION:  The County proposes to modify the 0.25-mile segment of Foothill Expressway located between El Monte Avenue and San Antonio Road in the City of Los Altos for the purpose of improving traffic operations.  The proposed project was identified in the 2016 voter -approved Measure B, Expressway Program.  The primary components of the proposed project include: adding an auxiliary lane in each direction on Foothill Expressway between El Monte Avenue and San Antonio Road; adding a second right turn lane on southbound Foothill Expressway into El Monte Ave; adding a second through lane on wes tbound El Monte Avenue at the Foothill Expressway/El Monte Avenue intersection; squaring all four corners of the Foothill Expressway/El Monte intersection;  adding bike slots on Foothill Expressway;  and installing pedestrian sensors at the intersection of F oothill Expressway/El Monte Avenue.  All work would be within the existing public streets right-of -way and is anticipated to take approximately six months to complete. APPLICANT/LEAD AGENCY CONTACT INFORMATION: Santa Clara County Roads and Airports Department Attention: Christine Li, Project Manager 1 Skyport Drive / San Jose, California 95110 E mail: Christine.Li@rda.sccgov .org FINDING:  The County finds the project described above will not have a significant effect on the environment.  The attached Initial Study identifies one or more potentially significant effects on the environment for which mitigation measures are proposed to be implemented to reduce those effects to a less than significant level. The mitigation measures described in th e Initial Study and included in the proposed project are listed below. Foothill Expressway Operational Improvements 2 Mitigated Negative Declaration County of Santa Clara September 2018 A. Biological Resources In compliance with federal and State regulations and protocol, the project proposes to implement the following mitigation measure to reduce impacts to a less than significant level:

• 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 are a extends from February 1 through August 31. If it is n ot possible to schedule construction and tree removal between September 1 and January 31, then pre -construction surveys for nesting birds shall be completed by a qualified ornithologist to ensure no nests are disturbed during project implementation.  This survey shall be completed no more than 14 days prior to the initiation of grading, tree removal, or other demolition or construction activities during the early part of the breeding season
(February 1 through April 30) and no more than 30 days prior to the initiation of these activities during the late part of the breeding season (May 1 through August 31). During this survey, the ornithologist shall inspect all trees and other possible nesting habitats within and immediately adjacent to the construction area for nests.  If an active nest is found sufficiently close to work areas to be disturbed by construction, the ornithologist, in consultation with CDFW, shall determine the extent of a construction -free buffer zone to be established around the nest to ens ure that nests of bird species protected by the MBTA or Fish and Game code shall not be disturbed during project construction. B. Cultural Resources The project proposes to implement the following mitigation measures to avoid and/or reduce significant impacts to unknown archaeological resources to a less than significant level:

• Operations shall stop within 50 feet of the find and a qualified professional archaeologist shall be contacted for further review, evaluation, and recommendations consistent with CEQA and County of Santa Clara requirements.  Potential recommendations for treatment could include collection, recordation, and analysis of any significant cultural materials followed by a professional report and curation of materials with a responsible f acility. State law shall be followed in regards to the discovery of Native American burials (Chapter 92, Section 7050.5 to the Health and Safety Code, Sections 5097.94, 5097.98, and 6097.99 of the Public Resources Code).  If the remains are Native American, the Santa Clara County Medical Examiner has two working days to examine the remains and must notify the Native American Heritage Commission (NAHC) within 24 hours, if it is determined that the remains are Native American.  The NAHC will immediate ly appoint a Most Likely Descendant
(MLD)
who has 48 hours to provide recommendations to the land owner for the protection and treatment of the remains.  It is not yet known what type of recovery or treatment action might be recommended by the MLD.  If the descendent does not make recommendations within 48 hours, the County shall reinter the remains in an area of the property, secure from further disturbance.  If the County does not accept the MLD’s recommendations, the County or the MLD may request remedi ation by the NAHC. 1 California law uses the term “Most Likely Descendent” (MLD); that is, an individual recognized by the NAHC as most likely descended from the deceased Native American.  Under California law this individual can recommend appropriate treatment of Native Amer ican human remains (e.g., in situ preservation, exhumation, analyses, report, etc.) discovered during construction or other activities. Foothill Expressway Operational Improvements 3 Mitigated Negative Declaration County of Santa Clara September 2018 The project proposes to implement the following mitigation measure reduce impacts to unknown paleontological resources to a less than significant level:

• In the event that a fossil is discovered during construction of the project, excava tions within feet of the find shall be temporarily halted or delayed until the discovery is examined by a qualified paleontologist, in accordance with Society of Vertebrate Paleontology standards. The County shall include a standard inadvertent discove ry clause in every construction contract to inform contractors of this requirement.  If the find is determined to be significant and if avoidance is not feasible, the paleontologist shall design and carry out a data recovery plan consistent with the Society of Vertebrate Paleontology standards. C. Hazardous Materials The following measure would be implemented to reduce and/or avoid significant impacts related to possible soil contamination within the road alignment to a less than significant level :

• As part of project development, a soil investigation will be conducted to determine whether ADL and other toxins of concern have affected soils that will be excavated as part of the proposed project.  The testing shall be completed in accordance with a work plan prepare d by Santa Clara County Roads and Airports Department Environmental Health and Safety Compliance Specialist .  The work plan shall identify the sampling locations and methods and the analytical testing to be completed.  The analytical results will be compared against applicable hazardous waste criteria.  Based on analytical results, the investigation will provide recommendations regarding management and disposal of affected soils, if present. The recommendations shall be implemented by the project.  Examples of such recommendations include, but are not limited to, the preparation and implementation of a Health and Safety Plan to safeguard workers who would handle or be exposed to AD L and other toxins of concerns, BMPs to limit exposure to the public, and/or the transport of contaminated soil to an appropriate facility for disposal. Foothill Expressway Operational Improvements County of Santa Clara4Mitigated Negative Declaration September 2018 Project Site REGIONAL MAP FIGURE 1 Fremont Avenue Foothill E xpre ssway El Cami no Real North San Antonio Road Fremont Avenue Foothill Expressway E
l Camino Real North San Antonio Road Sunnyvale Cupertino Mountain View LosAltos Sunnyvale Cupertino Mountain View Los Altos Pacific Ocean Monterey Bay San JoséFremont Oakland San Francisco Santa CruzMountain View Morgan Hill San José Fremont LivermoreLivermore Oakland San Francisco Santa Cruz Mountain View Morgan Hill GilroyGilroy Project SiteProject Site San Francisco Bay Foothill Expressway Operational Improvements County of Santa Clara5Mitigated Negative Declaration September 2018 Foothill Expr essway Cuesta Drive Benvenue Avenue Hawthorne Avenue Lyell Street Glen Alto Drive Covington Road st Stree t
Pepper Drive Marvin Avenue Rosita Avenue Harrington Avenue University Avenue South El Monte Avenue South E l M onte Avenue West Fremont Road B
ur ke Road Okeefe L ane Palm Avenue Orange Avenue South San Antonio Road Giff in Road Cuesta DriveBenvenue Avenue Hawthorne Avenue Lyell Street Glen Alto Drive Covington Road st Street Pepper Drive Marvin Avenue Rosita Avenue Harrington Avenue University Avenue South El Monte Avenue South El Monte Avenue West Fremont Road Burke Road Okeefe Lane Palm Avenue Orange Avenue South San Antonio Road Giff in Road Foothill Expressway Foothill Expressway VICINITY MAP FIGURE 2 ay esswa aywaa prespresswayBase Map: ESRI, ArcGIS Project Site 500 1000 2000 Feet Foothill Expressway Operational Improvements County of Santa Clara6Mitigated Negative Declaration September 2018 AERIAL PHOTOGRAPH AND SURROUNDING LAND USES FIGURE 3 Cuesta Drive Griffin Road F
oothill Expressway Covington R oad Palm Avenue Orange Avenu e
Sheridan Street Sherman Street University Ave nue South El M onte Avenue Cuesta Drive Griffin Road Foothill Expressway Covington Road Palm Avenue Orange Avenue Sheridan Street Sherman Street University Avenue South El Monte Avenue Residential Residential Residential Residential Commerical Commerical Covington Elementary School Aerial Source: Google Earth Pro, May 22, 2018.Photo Date:  May 20180 500100 1000 Feet Project Boundary Land Uses ResidentialCommercial Foothill Expressway Operational Improvements i Initial Study County of Santa Clara September 2018 TABLE OF CONTENTS Section 1.0 Introduction and Purpose ................................................................................................  1
.1 Purpose of the Initial Study ....................................................................................................  1
.2 Public Review Period .............................................................................................................  1
.3 Consideration of the Initial Study and Project ........................................................................  1
.4 Notice of Determination .........................................................................................................  1 Section 2.0 Project Information .........................................................................................................  2
.1 Project Title ............................................................................................................................  2
.2 Lead Agency Contact and project proponent .........................................................................  2
.3 Project Location ......................................................................................................................  2
.4 Project-Related Approvals, Agreements, and Permits ............................................................ 2 Section 3.0 Project Description ..........................................................................................................  6 Section 4.0 Environmental Checklist and Impact Discussion ........................................................... 8
.1 Resources not affected by the project .....................................................................................  8
.2 Aesthetics ................................................................................................................................  9
.3 Air Quality ............................................................................................................................  14
.4 Biological Resources ............................................................................................................  19
.5 Cultural Resources ................................................................................................................  23
.6 Geology and Soils .................................................................................................................  27
.7 Greenhouse Gas Emissions ...................................................................................................  30
.8 Hazards and Hazardous Materials ........................................................................................  33
.9 Hydrology and Water Quality ..............................................................................................  37
.10 Land Use and Planning .........................................................................................................  42
.11 Noise and Vibration ..............................................................................................................  44
.12 Transportation/Traffic...........................................................................................................  49
.13 Mandatory Findings of Significance ....................................................................................  53 Section 5.0 References .....................................................................................................................  57 Section 6.0 Lead Agency and Consultants  .......................................................................................  59
.1 Lead Agency .........................................................................................................................  59
.2 Consultants ...........................................................................................................................  59 Foothill Expressway Operational Improvements ii Initial Study County of Santa Clara September 2018 TABLE OF CONTENTS Figures Figure 2.3-1: Regional Map  ...................................................................................................................  3 Figure 2.3-2: Vicinity Map ....................................................................................................................  4 Figure 2.3-3: Aerial Photo and Surrounding Uses .................................................................................  5 Figure 3.0-1: Proposed Improvement on Foothill Expressway  .............................................................  7 Figure 4.2-1: Tree Locations Map .......................................................................................................  13 Photos Photo 1: View of El Monte Aveue and Foothill Expressway looking west ......................................... 12 Photo 2: View of Foothill Expressay looking north  ............................................................................ 12 Tables Table 4.2-1: Summary of Existing Protected Trees to be Removed  .................................................... 10 Table 4.12-1: Foothill Expressway/El Monte Avenue Intersection Operations  ..................................  51 Table 4.12-2: Foothill Expressway/San Antonio Road I ntersection Operations .................................  51 Appendices Appendix A:  Noise Assessment Appendix B:  Traffic Operational Analysis Report Foothill Expressway Operational Improvements 1 Initial Study County of Santa Clara September 2018 SECTION 1.0 INTRODUCTION AND PURPOSE
.1 PURPOSE OF T HE INITIAL STUDY The San ta Clara County Roads & Airports Department  (County) as the owner and operator of Foothill Expressway , has prepared this Initial Study for the Foothill Expressway Operational Improvements in compliance with the California Environmental Quality Act (CEQA), the CEQA Guidelines (California Code of Reg ulations §15000 et. seq.) and the regulations and policies of the County of Santa Clara , California. The project proposes to implement improvements to a 0.25-mile segment of Foothill Expressway , between El Monte Avenue and San Antonio Road, in the City of Los Altos .  This Initial Study evaluates the environmental impacts that might reasonably be anticipated to result from implementation of the proposed project. Based on the findings in this Initial Study, the proposed project, with implementation of mitig ation measures, would not result in significant environment al impacts . .2 PUBLIC REVIEW PERIOD Publication of this Initial Study marks the beginning of a 20-day public review and comment period. During this period, the Initial Study will be available to loc al, state, and federal agencies and to interested organizations and individuals for review.  Written comments concerning the environmental review contained in this Initial Study during the 20-day public review period should be sent to: Christine Li Santa Clara County Roads and Airports Department 1 Skyport Drive San José, CA 95110 Christine.Li@rda.sccgov.org Based on the conclusions of the analyses contained in this Initial Study, the County intends to adopt a Mitigated Negative Declaration (MND) under CEQA. .3 CONSIDERATION OF THE INITIAL STUDY AND PROJECT F ollowing the conclusion of the public review period, the Santa Clara County Board of Supervisors, as the decision -making body for the project , will consider the adoption of the MND at a regularly scheduled meeting.  The Board of Supervisors shall consider the Initial Study together with any comments received du ring the public review process.  Upon adoption of the MND, the County may proceed with projec t approval actions. .4 NOTICE OF DETERMINAT ION If the project is approved, the County will file a Notice of Determination (NOD), which will be available for public inspection and posted within 24 hours of receipt at the County Clerk’s Office for days.  The filing of the NOD starts a 30 -day statute of limitations on court challenges to the approval under CEQA (CEQA Guidelines Section 15075(g)). Foothill Expressway Operational Improvements 2 Initial Study County of Santa Clara September 2018 SECTION 2.0 PROJECT INFORMATION .1 PROJECT TITLE Foothill Expressway Operational Improvement s .2 LEAD AGENCY CONTACT AND PROJECT PROPONENT Christine Li Santa Clara County Roads & Airports Department 1 Skyport Drive San José, CA 95110 (408) 573-2488 .3 PROJECT LOCATION The project site is located in the City of Los Altos on a 0.25-mile segment of Foothill Expressway, between El Mo nte Avenue and San Antonio Road. Foothill Expressway is operated and maintained by the Santa Clara County Roads & Airports Department. The project location is shown on Figure
.3-1: Regional Map, Figure 2.3-2: Vicinity Map, and Figure 2.3-3: Aerial Pho to and Surrounding Uses. .4 PROJECT-RELATED APPROVALS, AGREEMENTS, A ND PERMITS The project will require approval from the Santa Clara County Board of Supervisors.  Any work within adjacent right-of -way owned by the City of Los Altos will require approvals and/or encroachment permits from the City. Foothill Expressway Operational Improvements County of Santa Clara3Initial Study September 2018 Project Site REGIONAL MAP FIGURE 2.3-1 Fremont Avenue Foothill E xpre ssway El Cami no Real North San Antonio Road Fremont Avenue Foothill Expressway E
l Camino Real North San Antonio Road Sunnyvale Cupertino Mountain View LosAltos Sunnyvale Cupertino Mountain View Los Altos Pacific Ocean Monterey Bay San JoséFremont Oakland San Francisco Santa CruzMountain View Morgan Hill San José Fremont LivermoreLivermore Oakland San Francisco Santa Cruz Mountain View Morgan Hill GilroyGilroy Project SiteProject Site San Francisco Bay Foothill Expressway Operational Improvements County of Santa Clara4Initial Study September 2018 Foothill Expr essway Cuesta Drive Benvenue Avenue Hawthorne Avenue Lyell Street Glen Alto Drive Covington Road st Stree t
Pepper Drive Marvin Avenue Rosita Avenue Harrington Avenue University Avenue South El Monte Avenue South E l M onte Avenue West Fremont Road B
ur ke Road Okeefe L ane Palm Avenue Orange Avenue South San Antonio Road Giff in Road Cuesta DriveBenvenue Avenue Hawthorne Avenue Lyell Street Glen Alto Drive Covington Road st Street Pepper Drive Marvin Avenue Rosita Avenue Harrington Avenue University Avenue South El Monte Avenue South El Monte Avenue West Fremont Road Burke Road Okeefe Lane Palm Avenue Orange Avenue South San Antonio Road Giff in Road Foothill Expressway Foothill Expressway VICINITY MAP FIGURE 2.3-2 ay esswa aywaa prespresswayBase Map: ESRI, ArcGIS Project Site 500 1000 2000 Feet Foothill Expressway Operational Improvements County of Santa Clara5Initial Study September 2018 AERIAL PHOTOGRAPH AND SURROUNDING LAND USES FIGURE 2.3-3 Cuesta Drive Griffin Road F
oothill Expressway Covington R oad Palm Avenue Orange Avenu e
Sheridan Street Sherman Street University Ave nue South El M onte Avenue Cuesta Drive Griffin Road Foothill Expressway Covington Road Palm Avenue Orange Avenue Sheridan Street Sherman Street University Avenue South El Monte Avenue Residential Residential Residential Residential Commerical Commerical Covington Elementary School Aerial Source: Google Earth Pro, May 22, 2018.Photo Date:  May 20180 500100 1000 Feet Project Boundary Land Uses ResidentialCommercial Foothill Expressway Operational Improvements 6 Initial Study County of Santa Clara September 2018 SECTION 3.0 PROJECT DESCRIPTION The County proposes to implement improvements to a 0.25-mile segment of Foothill Exp ressway between El Monte Avenue and San Antonio Road in the City of Los Altos for the purpose of improving traffic operations. 1 The proposed improvements was identified in the voter-approved 16 Measure B, Express way Program. The primary components of the proposed project are as follows:

• An auxiliary lane would be constructed in each direction on Foothill Expressway between El Monte Avenue and San Antonio Road.  This would involve widening on the west side of Foothill Expressway and reducing the medi an width to accommodate the auxiliary lanes.

• At t he Foothill Expressway/El Monte Avenue intersection, the proposed improvements would include adding a 2 nd right turn lane on southbound Foothill Expressway, and a 2nd through lane on westbound El Monte Ave nue.  In addition, all four corners of the intersection would be squared.

• Bike slots on Foothill Expressway and pedestrian sensors at the intersection of Foothill Expressway/El Monte Avenue would be installed. Construction of the above -listed improvements would consist of road widening, geometric modification, modification of traffic signals, pavement resurfacing, pavement delineation, and other improvements necessary to implement the project.  All work would be within the existing public streets rights -of-way and is anticipated to take approximately six months to complete. Refer to Figure 3.0-1 for the conceptual plan of the proposed improvement s. 1 For the purposes of this Initial Study, Foothill Expressway is described as a north/south roadway. Foothill Expressway Operational Improvements County of Santa Clara7Initial Study September 2018PROPOSED IMPROVEMENT ON FOOTHILL EXPRESSWAY FIGURE 3.0-1 Foothill Expressway Operational Improvements 8 Initial Study County of Santa Clara September 2018 SECTION 4.0 ENVIRONMENTAL CHECKLIST AND IMPACT DISCUSSION This section presents the discussion of impacts related to the following environmental subjects in their respective subsections : .1 Aesthetics
.2 Air Quality .3 Biological Resources .4 Cultural Resources .5 Geology and Soils .6 Greenhouse Gas Emissi ons .7 Hazards and Hazardous Materials
.8 Hydrology and Water Quality .9 Land Use and Pl anning .10 Noise and Vibration .11 Transportation/Traffic .12 Mandatory Findings of Significance The discussion for each environmental subject includes the following subsections:

• Environmental Checklist – The environmental checklist, as recommended in the CEQA Guidelines , identifies environmental impacts that could occur if the proposed project is implemented.  The right -hand column of the checklist lists the source(s) for the answer to each checklist question.  The sources are identified at the end of this section.

• Impact Discussion – This subsection discusses the project’s impact as it relates to the environmental checklist questions .  For significant impac ts, feasible mitigation measures are identified.  “Mitigation measures” are measures that will minimize, avoid, or eliminate a signi ficant impact (CEQA Guidelines Section 15370).  Each impact is numbered using an alphanumeric system that identifies the environmental issue.  For example, Impact HAZ -1 denotes the first potentially signi ficant impact discussed in the Hazards and H azardous M aterials section.  Mitigation measures are also numbered to correspond to the impact they address.  For example, MM NOI-2.3 refers to the third mitigation measure for the second impact in the Noise sub section. .1 RESOURCES NOT AFFECT ED BY THE PROJECT The project proposes operational improvements to a n existing 0.25-mile segment of Foothill Expressway , between El Monte Avenue a nd San Antonio Road, in the City of Los Altos .  Compared to existing conditions on Foothill E xpressway, the proposed project would not generate new vehicle trips, increase traffic volumes, or otherwise intensify the use of Foothill Expressway and the surrounding roadway system.  The pro je ct would not extend or increase the capacity of existing utilities, increase demand upon existing utilities or public services, or create new jobs or housing. The proposed improvements would occur within existing, develope d public right-of-way.  For these reasons, the proposed project would not result in impacts to agricultural and forestry resources , mineral resources, population and housing, public services, recreation, or utilities and service systems, and these resource areas are not discussed further in this Initial Study. Foothill Expressway Operational Improvements 9 Initial Study County of Santa Clara September 2018
.2 AESTHETICS .2.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Have a substantial adverse effect on a scenic vista? b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? 2,4 c) Substantially degrade the existing visual character or quality of the site and its surroundings? 1,2,3 d) Create a new source of substantial light or glare which will adversely affect day or nighttime views in the area? .2.2 Impact Discussion a) Have a substantial adverse effect on a scenic vista? A scenic vista is generally defined as an expanded view of an area that is visual ly and aesthetically pleasing.  The project is not located on a hill or along a ridgeline and is surrounded by existing deve lopment .  As a result, existing development and trees in the project area would limit views of the proposed improvements to the immediate vicinity. For these reasons, the proposed project would not have a substantial adverse effect on a scenic vista. (No Impact) b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? The project is not located within or visible from a designated S tate Scenic H ighway.  The near est officially designated State Scenic Highway is a segment of State Route 9, from Santa Cruz County line to the limits of the Town of Los Gatos, which is located approximately five miles south of the project. A segment of Interstate 280, which is locate d approximately 0.75 miles southwest of the project is eligible, however not officially designated as a State Scenic Highway. Therefore, the proposed project would not damage scenic resources within a state scenic highway .  (No Impact) 2 California Department of Transportation. “California Scenic Highway Mapping System.”  Accessed: March 26, 17.  Available at:  http://www.dot.ca.gov/hq/LandArch/16_livability/scenic_highways/
. 3 Ibid. Foothill Expressway Operational Improvements 10 Initial Study County of Santa Clara September 2018 c)  Substantially degrade the existing visual character or quality of the site and its surroundings? The project proposes roadway improvements to Foothill Expressway. In the project area, Foothill Expressway is a four-lane facility (two lanes in each direction) with a rai sed center median. The project area along the expressway is developed with one - and two-story single-family residences and apartment and office buildings.  Soundwalls are located along the west side and fences are located along the east side of Foothill Expressway in the project area.  Refer to Photos 1 and 2 for views of the existing roadway segment. Within the project limits, the trees and shrubs that are planted in the median and along both sides of the expressway within the ex pressway right-of-way constitute an important component of the existing visual and aesthetic environment.  Based on a 2017 tree survey undertaken by an arborist, the re are 165 existing trees along the expressway between El Monte Avenue and San Antonio Road. This number is based on a conservative definition of a “tree” as any woody plant having a trunk with a diameter of one inch or greater at a height of 4.5 feet above the ground.  The tree protection ordinances of most jurisdiction define a tree using larger diameters.  For example, the County’s Tree Preservation Ordinance definition of a tree, which is applicable to this proposed project, is a woody plant having a diameter of 12 inches or greater at a height of 4.5 above the ground.  Using the County’s definition , there are 32 trees along Foothill Expressway between El Monte Avenue and San Antonio Road.  Further, the County’s Tree Preservation Ordinance defines all trees within the expressway right -of-way as “protected.” Of the 32 existing protected trees, the project would remove a total of 17 trees .  These trees are listed in Tab le 4.2-1 and their locations are shown on Figure 4.2-1. Table 4.2-1: Summary of Existing Protected Trees to be Removed Tree ID# Common Name Diameter (inches)
9 Sweetgum 20 0 Sweetgum 18 1 Sweetgum 15 2 Sweetgum 14 4 Sweetgum 14 5 Sweetgum 13 6 Sweetgum 15 6 Sweetgum 15 7 Sweetgum 16 8 Sweetgum 14 0 Sweetgum 15 2 Monterey Pine 36 3 Sweetgum 15 4 Sweetgum 14 5 Sweetgum 20 6 Sweetgum 22 3 Deodar Cedar 13 Foothill Expressway Operational Improvements 11 Initial Study County of Santa Clara September 2018 Consistent with the requirements of the County’s Tree Preservation Ordinance, a minimum of 17 replacement trees would be planted.  The project proposes to plant 19 replacement trees, all of which would occur within the project limits along the east side of the existing Foothill Expressway right-of-way and in the median island north of San Antonio Road. Despite the above-described tree removal, the proposed roadway improvements do not include elevated travel lanes, new sources of light and glare, or other structures that would change the visual character of the project area.  Further, most of the existing vegetation would not be impacted, while the 17 trees to be removed would be replaced onsite.  Therefore, it is concluded that the proposed project would not substantially degrade the existing visual character or quality of the site and it surroundings. (Less Than Significant Impact) d) Create a new source of substantial light or glare that would adversely affect day or nighttime views in the area? The proposed roadway improvements do not include elevated travel lanes, new sources of light or glare, reflective surfaces or other features that could create substantially light or glare.  (No Impact)
Foothill Expressway Operational Improvements 12 Initial Study County of Santa Clara September 2018 Photo 1: View of El Monte Aveue and Foothill Expressway looking west Photo 2: View of Foothill Expressay looking north Foothill Expressway Operational Improvements County of Santa Clara13Initial Study September 2018
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" 15"
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TREE LOCATIONS MAP FIGURE 4.2-10 50 100 200 Feet TREES ≥ 12 INCHES EXISTING All
≥ 12 INCHES TO BE REMOVED TREES TO BE REMOVED TREES ≥ 12 INCHES TO BE REMOVED F oothill Expressway Operational Improvements 14 Initial Study County of Santa Clara September 2018
.3 AIR QUALITY .3.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project:
a)Conflict with or obstruct implementation of the applicable air quality plan? ,5 b)Violate any air quality standard or contribute substantially to an existing or proj ected air quality violation? ,6 c)Result in a cumulatively considerable net increase of any criteria pollutant for which the pr oject region is classified as non- attainmen t
und er an applicable federal or state ambient air quality standard including releasi ng e
missions which exceed quantitative thresholds for ozone precursors?
d)Expose sensitive receptors to substantial pollutant concentrations?
,6 e)Create objectionable odors affecting a substantial number of people?
.3.2 Impact Discussion The Bay Area Air Quality Management District ( BAAQMD) has adopted thresholds of significance to assist the review of projects under CEQA.  These thresholds were designed to establish the level at which BAAQMD re ports air pollution emissions would cause significant environmental impacts. The significance thresholds identified by BAAQMD and used in this analysis are summarized in Table 4.3-1. A s discussed in CEQA Guidelines Section 15064(b), the determination of whether a project may have a significant effect on the environment calls for careful judgment on the part of the Lead Agency and must be based to the extent possible on scientific and factual data.  The County has carefully considered the thresholds upda ted by BAAQMD in May 2017.  The County regards these thresholds to be based on the best information available for the San Francisco Bay Area Air Basin and conservative in terms of the assessment of health effects associated with toxic air contaminants
(TAC s) and particulate matter ( PM).  The BAAQMD CEQA thresholds used in this analysis are identified in Table 4.3-1 below. Foothill Expressway Operational Improvements 15 Initial Study County of Santa Clara September 2018 Table 4.3-1: Thresholds of Significance Used in Air Quality Analyses Pollutant Construction Operation Average Daily Emissions (pounds)  Average Daily Emissions (pounds)  Maximum Annual Emissions (tons) Reactive Organic Gases (ROG), Nitrogen Oxides (NO x) 54 Particulate Matter, 10 microns in size (PM
)  82 (exhaust) 82 15 Particulate Matter, 2.5 microns in size (PM
.5)  54 (exhaust) 54 10 Fugitive Dust
(PM
/PM2.5)  Implement Best Management Practices None None Risk and Hazards for New Sources and Receptors (Project)  Same as operational threshold

• Increased cancer risk of >10.0 in one million

• Increased non- cancer risk of > 1.0 Haz ard Index (chronic or acute)

• Ambient PM
.5 increase: > 0.3 µ/m3
(Zone of influence: 1,000- foot radius from property line of source or receptor) Risk and Hazards for New Sources and Receptors
(Cumulative)  Same as operational threshold

• Increased cancer risk of >100 in one million

• Increased non- cancer risk of > 10.0 Hazard Index (chronic or acute)

• Ambient PM
.5 increase: > 0.8 µ/m3
(Zone of influence: 1,000- foot radius from property line of source or receptor) Sources: BAAQMD CEQA Thresholds Options and Just ification Report (2009) and BAAQMD CEQA Air Quality Guidelines (dated May 2017). Note: For stationary source projects, modeling for carbon monoxide ( CO) concentrations is only required for projects emitting 100 tons per year or more of CO.  Projects emitt ing less are assumed to not exceed the CO concentration threshold. a)  Conflict with or obstruct implementation of the applicable air quality plan? The air quality plan applicable to the project is the 2017 BAAQMD Clean Air Plan (CAP).  The proposed project includes roadway improvements to a 0.25-mile segment of Foothill Expressway that would improve operations and alleviate traffic congestion.  Operation of the project would not generate new vehicle trips and associated air pollutant emissions or otherw ise result in a significant air quality impact. The proposed project would not conflict with the 2017 CAP because it would have emissions below BAAQMD impact thresholds for new development and serves existing urban Foothill Expressway Operational Improvements 16 Initial Study County of Santa Clara September 2018 infill development.  Because the project would not exceed the BAAQMD impact thresholds, it is not required to incorporate any of the project-specific control measures that are listed in the 2017 CAP. Further, implementation of the project would not inhibit BAAQMD or partner agencies from contin uing progress toward attaining state and federal air quality standards and eliminating health -risk disparities from exposure to air pollution among Bay Area communities, as described within the 17 CAP. As discussed below, the proposed project would implement the Basic Construction Mitigation Measures Recommended for All Projects identified in the BAAQMD CEQA Air Quality Guidelines and, therefore, would not result in significant construction air quality impacts.  For these reasons, the proposed project w ould not conflict with or obstruct the implementation of the 2017 CAP .  (No Impact) b) Violate any air quality standard or contribute substantially to an existing or projected air quality violation? The proposed project includes roadway improvements to a 0.25-mile segment of Foothill Expressway that would improve operations and alleviate traffic congestion.  As noted above, operation of the proposed project would not generate new air pollutant emissions.  As discussed below, the proposed project would imp lement the Basic Construction Mitigation Measures Recommended for All Projects identified in the BAAQMD CEQA Air Quality Guidelines.  For these reasons, the proposed project would not violate or contribute to the violation of an existing or projected air quality standard.  (Less Than Significant Impact ) c) Result in a cumulatively considerable net 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? The proposed project includes roadway improvements to a 0.25 -mile segment of Foothill Expressway that would improve operations and alleviate traffic congestion.  A s noted above, operation of the proposed project would not generate new air pollutant emissions and, therefore, would not result in a cumulatively considerable criteria pollutant net increase. Construction activities, particularly during ground disturbing activities, would temporarily generate fugitive dust in the form of PM and PM2.5.  Sources of fugitive dust would include disturbed soils at the construction site and trucks carrying uncovered loads of soils.  Unless properly controlled, vehicles leavin g the site would deposit dirt or mud on local streets, which could be an additional source of airborne dust.  BAAQMD conside rs these impacts to be less than significant if controlled through implementation of the Basic Construction Mitigation Measures Reco mmended for All Projects identified in BAAQMD CEQA Air Quality Guidelines . Standard Measures:  The project shall include the following standard BAAQMD construction BMPs to control dust and exhaust during construction:

• All exposed surfaces (e.g., parking a reas, staging areas, soil piles, graded areas, and unpaved access roads) shall be watered two times per day. Foothill Expressway Operational Improvements 17 Initial Study County of Santa Clara September 2018

• All haul trucks transporting soil, sand, or other loose material off -site shall be covered.

• All visible mud or dirt track -out onto adjacent public roads shall be removed using wet power vacuum street sweepers at least once per day.  The use of dr y power sweeping is prohibited.

• All vehicle speeds on unpaved surface s shall be limited to 15 miles per hour (mph).

• All roadways, driveways, and sidewalks to be paved shall be completed as soon as possible.

• Idling times shall be minimized either by shutting equipment off when not in use or reducing the maximum idling time to five minutes (a s required by the California Airborne Toxics Control M easure Title 13, Section 2485 of California Code of Regulations [CCR]).  Clear signage shall be provided for construction workers at all access points.

• All construction equipment shall be maintained and properly tuned in accordance with manufacturer’s specifications.  All equipment shall be checked by a certified mechanic and determined to be running in proper condition prior to operation.

• A publicly -visible sign shall be posted with the telephone number and pers on to contact at the construction firm regarding dust complaints.  This person shall respond and take corrective action within 48 hours.  The BAAQMD phone number shall also be visible to ensure compliance with applicable regulations. The project, with the implementation of the above standard measures, would reduce c onstruction related emissions to a less than significant level by controlling dust and exhaust and limiting exposed soil surfaces.  (Less Than Significant Impact ) d) Expose sensitive receptors to substantial pollutant concentrations? “Sensitive receptors” ar e groups of people more affected by air pollution than others.  The California Air Resources Board (CARB) has identified the following groups of people in this category : children under 14 years of age, people over 65 years of age, athletes, and people with cardiovascular or chronic respiratory diseases.  Locations that may contain high concentrations sensitive receptors include residential areas, hospitals, daycare facilities, elder care facilities, elementary schools, and parks.  The nearest sensitive receptors to the proposed project are the residences located east and west of Foothill Expressway. Operation As noted above, operation of the proposed project would not generate new air pollutant emissions and, therefore, would not expose sensitive rece ptors in the project area to substantial pollutant concentrations. Construction Dust Construction activities associated with the proposed project c ould temporarily expose sensitive receptors fugitive dust in the form of PM and PM2.5.  As discussed abov e, however, impacts related to fugitive dust area considered less than significant with implementation of applicable measures from BAAQMD’s Basic Construction Mitigation Measures Recommended for All Projects , which are included in the proposed project. Foothill Expressway Operational Improvements 18 Initial Study County of Santa Clara September 2018 Constr uction Toxic Air Contaminants  – Diesel Particulates The exhaust from diesel -powered construction equipment contains diesel particulate matter (DPM), a known carcinogen and toxic air contaminant (TAC).  Construction of the proposed project is anticipat ed to take approximately six months to complete, during which time the use of diesel -powered equipment is anticipated.  However, g iven the short duration and relatively low intensity of construction activities associated with the proposed project, construc tion activities would not expose sensitive receptors in the project area to substantial doses or concentrations of DPM.  (Less Than Significant Impact) e) Create objectionable odors affecting a substantial number of people? The proposed project includes roadway improvements to a 0.25 -mile segment of Foothill Expressway that would improve operations and alleviate traffic congestion.  Operation of the proposed roadway improvements would not generate odors. Odors from construction equipment (e.g., diesel exhaust) and materials (e.g., asphalt) may be noticeable during construction of the proposed project.  Project construction would be temporary ;
therefore, odors generated during construction activities are not considered significant.  (Less Than Significa nt Impact)
Foothill Expressway Operational Improvements 19 Initial Study County of Santa Clara September 2018
.4 BIOLOGICAL RESOURCES .4.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Have a substantial adverse effect, either 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  (CDFW)  or United States Fish and Wildlife Service
(USFWS)? b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations, or by the CDFW or USFWS ? c) Have a substantial adverse effect on federally 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? d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, impede the use of native wildlife nursery sites? e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? 1,3 f) Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? Foothill Expressway Operational Improvements 20 Initial Study County of Santa Clara September 2018
.4.2 Impact Discussion a) Have a substantial adver se effect, either directly or through habitat modifications, on any species identified as a c andidate, sensitive, or special -status species in local or regional plans, policies, or regulations, or by the CDFW or USFWS? The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Avenue.  The project area is developed with urban uses and does not support habitat utilized by special -status plant or animal species. Tree Nesting Birds Migrator y birds and/or raptors are protected under the Migratory Bird Treaty Act  (MBTA) and State Fish and Game Codes and may nest in the trees within and adjacent to the proposed roadway improvements.  If construction takes place during the breeding season (February 1 through August
), disturbance could result in the incidental loss of fertile eggs or nestlings, or could otherwise lead to nest abandonment  – considered a “take” by the California Department of Fish & Wildlife (CDFW )
and, therefore, would constitut e a significant impact. Impact BIO -1: Construction activities and tree removal during the nesting season could result in the lo ss of fertile eggs, nesting raptors or other migratory birds, or nest abandonment . Mitigation Measure:  In compliance with federal and State regulations and protocol, the project proposes to implement the following mitigation measure to reduce impacts to a less than significant level. MM BIO -1: Construction shall be schedule d to avoid the nesting season to the extent feasi ble. The nesting season for most birds, including most raptors, in the San Francisco Bay are extends from February 1 through August 31. If it is not possible to schedule construction and tree removal between September and January 31, then pre-construction surveys for nesting birds shall be completed by a qualified ornithologist to ensure no nests are disturbed during project implementation.  This survey shall be completed no more than 14 days prior to the initiation of grading, tree removal, or other demolition or construction activities during the early part of the breeding season (February 1 through April
) and no more than 30 days prior to the initiation of these activities during the late part of the breeding season (May 1 through August 31). During this survey, the ornithologist shall inspect all trees and other possible nesting habitats within and immediately adjacent to the construction area for nests.  If an active nest is found sufficiently close to work areas to be disturbed by construction, the ornithologist, in consultation with CDFW, shall determine the extent of a construction-free buffer zone to be established around the nest to ensure that nests of bird species protected by the MBTA or Fish and Game code shall not be disturbed during project construction. Foothill Expressway Operational Improvements 21 Initial Study County of Santa Clara September 2018 The project, with implementation of the above mitigation measure, would reduce impacts to nesting birds (if present) by avoiding construction during nesting bird season or completing pre -construction nesting bird surveys to minimize and/or avoid impacts to nesting birds.  (Le ss Than Significant Impact with Mitigation Incorporated) b) Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulation s, or by the CDFW or USFWS? The proposed roadway improvements are located in the City of Los Altos in an area developed with urban uses that does not support sensitive habitat.  The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Avenue.  There are no waterways or riparian habitat located within or adjacent to the areas of the proposed roadway improvements.  The nearest waterway is Adobe Creek, which is located approximately 0.25 mile s west of the proposed project.  For these reasons, the proposed project would not have a substantial adverse effect on riparian habitat or other sensitive natural community.  (No Impact) c) Have a substantial adverse effect on federally 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? The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Avenue .  There are no water bodies or wetlands located on or adjacent to the proposed project;  therefore, the implementation of the project would not have a substantial adverse effect on wetlands .  (No Impact) d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, impede the use of native wildlife nursery sites? The setting of the proposed project i s an existing expressway located in an area developed with urban uses.  The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road.  There are no waterways located wi thin or adjacent to the proposed project.  For these reasons, the project area does not function as a wildlife corridor or wildlife nursery site, and the project would not substantially interfere with the movement of fish or wildlife or impede the use of wildlife nursery sites. (No Impact) e) Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? The project is subject to the requirements of the Santa Clara County Tree Protection and Preservation Ordinance.  A number of t rees, as defined under the ordinance, will be removed by the project and will be replaced per the requirements of the ordinance.  As discussed in Section 4.2 Aesthetics for a detailed discussion of this subject.  Based on that discussion, the project would not conflict with the Santa Clara County Tree Protection and Preservation Ordinance.  (No Impact)
Foothill Expressway Operational Improvements 22 Initial Study County of Santa Clara September 2018 f)  Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other ap proved local, regional, or state habitat conservation plan? The proposed project is not located within the boundaries of an adopted Habitat Conservation Plan, N atural Community Conservation Pl an, or other approved local, regional, or state habitat conserv ation plan and, therefore, would not conflict with such plans.  (No Impact)
Foothill Expressway Operational Improvements 23 Initial Study County of Santa Clara September 2018
.5 CULTURAL RESOURCES The following discussion is based, in part, on an archaeological resource assessment prepared by Basin Res earch Associates in February 2017.  The archaeologic al resource assessment may discuss locations of specific archaeological sites and, therefore, is confidential.  For this reason, it is not included in this Initial Study.  Qualified personnel, however, may request a copy of the report from the Santa Clara County Roads & Airports Department during normal business hours. .5.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Cause a substantial adverse change in the significance of an his torical resource as defined in CEQA Guidelines Section 064.5? 1,20 b) Cause a substantial adverse change in the significance of an archaeological resource as defined in CEQA Guidelines Section 064.5? 1,20 c) Directly or indirectly destroy a unique paleontological resource or site, or unique geologic feature? 1,20 d) Disturb any human remains, including those interred outside of dedicated cemeteries? 1,20 e) Cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code Section 074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is: . Listed or eligible for listing in the California Register of Historical Resources, or in a local register of historical resources as de fined in Public Resources Code Section 5020.1(k); or 1,20 Foothill Expressway Operational Improvements 24 Initial Study County of Santa Clara September 2018 Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: . A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant purs uant to criteria set forth in subdivision (c) of Public Resources Code Section 5024.1.  In applying this criteria, the significance of the resource to a California Native American tribe shall be considered. 1,20 .5.2 Impact Discussion a) Cause a substantial adverse change in the significa nce of an historical resource? The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road.  No structures would be removed or physically affected as a result of the proposed project.  There are no known historic resources or heritage trees located within or adjacent to the area of the proposed project.  The nearest known historic resource is the Orange University Historic District , which is located approximately 0.3 miles southeast of the proposed roadway improvements. For these reasons, the proposed project would not impact historic resources.  (No Impact ) b,d)  Cause a substantial a dverse change in the significance of an archaeological resource ? Disturb any human remains, including those interred outside of dedicated cemeteries? The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road in areas that have been repeatedly disturbed over the past 60 years during construction and maintenance of the existing expressway and related improvements including subsurface infrastructure.  As a result, most project -related construction activities would occur within areas of non-native fill and/or previously disturbed areas.  Based on the results of the Archaeological Resource Assessment completed for the project, there are no known archaeological resources located within or adjacent to the proposed project.  For these reasons, the potential for intact archaeological resources to be present in the areas of the proposed roadway improvements is low. There is always the possibility, however, that archaeological resources (including human remains)
could be uncovered during excavation.  The disturbance of these resources, if they are encountered during construction activities, could result in an impact. Impact CUL -1:  Although unlikely, unknown cultural resources could be encountered during excavation activities associated with the proposed project. 4 City of Los Altos.  Historic Resources Inventory.  October 2012. Foothill Expressway Operational Improvements 25 Initial Study County of Santa Clara September 2018 Mitigation Measures:  The project proposes to implement the following mitigation measures to avoid and/or reduce significant impacts to unknown archaeological resources to a less than significant level: MM CUL -1.1:  Operations shall stop within 50 feet of the find and a qualified professional archaeologist shall be contacted for further review, evaluation, and recommendations consistent with CEQA and County of Santa Clara requirements.  P otential recommendations for treatment could include collection, recordation, and analysis of any significant cultural materials followed by a professional report and curation of materials with a responsible facility. MM CUL -1.2:  State law shall be followed in regards to the discovery of Native American burials (Chapter 1492, Section 7050.5 to the Health and Safety Code, Sections 5097.94, 5097.98, and 6097.99 of the Public Resources Code).  If the remains are Native American, the Santa Clara County Medic al Examiner has two working days to examine the remains and must notify the Native American Heritage Commission (NAHC) within 24 hours , if it is determined that the remains are Native American.  The NAHC will immediately appoint a Most Likely Descendant (M LD)
who has 48 hours to provide recommendations to the land owner for the protection and treatment of the remains.  It is not yet known what type of recovery or treatment action might be recommended by the MLD.  If the descendent does not make recommendat ions within 48 hours, the County shall reinter the remains in an area of the property, secure from further disturbance.  If the County does not accept the MLD’s recommendations, the County or the MLD may request remediation by the NAHC. (Less Than Signi ficant Impact with Mitigation Incorporated) c) Directly or indirectly destroy a unique paleontological resource or site, or unique geologic feature? Paleontological resources are the fossilized remains of organisms from prehistoric environments found in geologic strata. There are no known unique paleontological resources or sites, or unique geologic features present within or adjacent to the area of the proposed roadway improvements. Soils onsite consist of alluvial fans, which are relatively young soil , consisting of gravel, sand, and finer sediments.  In addition, most project -related construction activities would occur within areas of non-native fill and/or previously disturbed areas.  Therefore, the potential for intact paleontological resources to be present in the areas of the proposed roadway improvements is low. 5 California law uses the term “Most Likely Descendent” (MLD); that is, an individual recognized by the NAHC as most likely descended from the deceased Native American.  Under California law this indi vidual can recommend appropriate treatment of Native American human remains (e.g., in situ preservation, exhumation, analyses, report, etc.) discovered during construction or other activities. Foothill Expressway Operational Improvements 26 Initial Study County of Santa Clara September 2018 However, the possibility of paleontological resources being uncovered during project construction cannot be entirely dismissed.  The disturbance of these resources, if they are encountere d during construction activities, could result in an impact. Impact CUL -2:  Although unlikely, unknown paleontological resources could be uncovered during excavation activities associated with the proposed roadway improvements. Mitigation Measures: The project proposes to implement the following mitigation measure reduce impacts to unknown paleontological resources to a less than significant level: MM CUL -2:  In the event that a fossil is discovered during construction of the project, excavations wi thin 50 feet of the find shall be temporarily halted or delayed until the discovery is examined by a qualified paleontologist, in accordance with Society of Vertebrate Paleontology standards.  The County shall include a standard inadvertent discovery claus e in every construction contract to inform contractors of this requirement.  If the find is determined to be significant and if avoidance is not feasible, the paleontologist shall design and carry out a data recovery plan consistent with the Society of Vertebrate Paleontology standards. (Less Than Significant Impa ct with Mitigation Incorporated) e )  Cause a substantial adverse change in the significance of a tribal cultural resource that is: 1) listed or eligible for listing in the California Register of H istorical Resources, or in a local register of historical resources, 2) determined to be a significant resource to a California Native American tribe. As a part of the archaeological resource assessmen t, the NAHC was contacted for review of the Sacred Lan ds Files.  The results of the Sacred Lands Files review was negative.  Furthermore, no known Native American villages, post -contact settlements, trails, traditional or contemporary use areas have been identified within or adjacent to the area of the propos ed roadway improvements.  For these reasons, the proposed project would not impact tribal cultural resources. (No Impact) .5.3 Conclusion With the implementation of identified mitigation measures, the project would result in less than significant cultural re sources impacts.  (Less Than Significant Impact with Mitigation Incorporated)
Foothill Expressway Operational Improvements 27 Initial Study County of Santa Clara September 2018
.6 GEOLOGY AND SOILS .6.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist S ource(s)
Would the project: a) Expose people or structures to potential substantial adverse effects, including the risk of loss, injury, or death involving:
. Rupture of a known earthquake fault, as described on the most recent Alquist -Priolo Earth quake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault (r efer to Division of Mines and Geology Special Publication 42)? 1,21,22
. Strong seismic ground shaking? 1,21,11
. Seismic-related ground failure, including liquefaction? 1,21,22
. Landslides? 1,21,22 b) Result in substantial soil erosion or the loss of topsoil? 1,2,3 c) Be located on a geologic unit or soil that is 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? 1,21 d) Be located on expansive soil, as defined in Section 1803.5.3 of the California Building Code (2016), creating substantial risks to life or property? 1,23 e) Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater? On December 17, 2015, the California Supreme Court issued an opinion in “CBIA vs. BAAQMD”
holding that CEQA is primarily concerned with the impacts of project on the environment and generally does not require agencies to analyze the impact of existing conditions on a project unless the project could exacerbate the existing environmental hazards or risks.  Except for the potential for project construction activities to exacerbate soil erosion, the proposed project would not exacerb ate existing geology and soil conditions in the project area .  The discussion below of existing geological conditions in the project area affecting the project is for information only. Foothill Expressway Operational Improvements 28 Initial Study County of Santa Clara September 2018
.6.2 Impact Discussion a) Expose people or structures to potential substantial adverse effects, including the risk of los s, injury, or death involving: 1) rupture of a known earthquake fault, 2) strong seismic ground shaking, 3 ) seismic-related ground failure, or 4 ) landslides? The project area is relatively flat with no existing slope instability or landslide-related hazard . The project area is located in a seismically -active region and as such, would likely be subject to strong to very strong earthquake -induced ground shaking during the lifetime of the proposed project.  While there are no known active faults in the project area, ground shaking from regional fault rupture could damage the proposed project. 7 The proposed roadway improvements would not, however, exacerbate the rupture of a known earthquake fault, strong seismic ground shaking, seismic-related ground failure, or landslides.  As such, there would be no CEQA impact.  (No Impact) b) Result in substantial soil erosion or the loss of topsoil? The immediate and surrounding project area is relatively flat and there are no existing slope instability, erosion, or landslide related hazards.  The proposed improvements to Foothill Expressway would require additional paving within the project limits, which would not lead to increased erosion over the long -term.  Project construction activities, however, would temporarily expose soil to the erosive forces of wind and water.  Any erosion or los s of topsoil associated with this temporary condition will be mitigated by the inclusion of water quality measures, a s listed in Section 4.9 Hydrology and Water Quality , measures are included in the proposed project to reduce erosion and associated impacts to water quality to a less than significant level.  (Less Than Significant Impact) c) Be located on a geologic unit or soil that is 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? The immediate and surrounding project area is relatively flat, and there is no existing slope instability, erosion, or landslide related hazards.  The project area is not mapped within a liquefaction zone . The roadway improvements would not, therefore, exacerbate on - or off-site landslide, lateral spreading, subsidence, liquefaction or co llapse.  (No Impact) d) Be located on expansive soil, as defined in Section 180 3.5.3 of the California Building Code
(2007), creating substantial risks to life or property? Soils at the project site have moderate to high expansion potential. Damage to th e proposed roadway improvements would be avoided using standard engineering design techniques that address expansive soils .  The roadway improvements would not , therefore, exacerbate the hazards of the existing on-site expansive soils .  As such, there would be no CEQA impact .  (No Impact) 6 California Department of Conservation.  Seismic Hazard Zone s, Los Gatos Quadrangle .  September 23, 2002.  7 California Department of Conservation.  Earthquake Fault Zones, Los Gatos Quadrangle .  November 1, 1991. 8 California Department of Conservation.  Seismic Hazard Zones, Los Gatos Quadrangle .  September 23, 2002.  9 United States Department of Agriculture. “Web Soil Survey.”  Accessed: March 28, 2018.  Available at:
https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
. Foothill Expressway Operational Improvements 29 Initial Study County of Santa Clara September 2018 e)  Have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater ? The project is limited to improvements to an existing roadway and will not generate waste.  As such, s eptic tanks or alternative wastewater disposal systems are not proposed by the project.  Therefore, this threshold is not applicable. (No Impact) .6.3 Conclusion The project would not result in signifi cant geology and soils impacts.  (Less Than Significant Impact)
Foothill Expressway Operational Improvements 30 Initial Study County of Santa Clara September 2018
.7 GREENHOUSE GAS EMISSIONS .7.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source( s)
Would the project: a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? 1,6,9 b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? 1,6,9 Greenhouse gas (GHG) emissions worldwide contribute, on a cumulative basis, to the significant adverse environmental impacts of global climate change.  No single land use project could generate sufficient GHG emissions on its own to noticeably change the global average temperature.  The combination of greenhouse gas emissions from past, present, and future projects in the County, the entire State of California, and across the nation and around the world, contribute cumulatively to global climate change and its associated environmental impacts. The following discussion foc uses on whether project emissions represent a cumulatively considerable contribution to climate change as determined by consistency with the County, City of Los Altos, and Statewide efforts to curb GHG emissions. BAAQMD Threshold of Significance The County and other jurisdictions in the San Francisco Bay Area Air Basin have used the thresholds and methodology for assessing air emissions and/or health effects in the BAAQMD CEQA Air Quality Guidelines (May 2011), which are based upon scientific and factual data prepared by BAAQMD in developing the thresholds. The County considers the BAAQMD thresholds to be based on the best information available for the San Francisco Bay Area Air Basin.  Under the BAAQMD CEQA Air Quality Guidelines, if a project will res ult in operational -related GHG emissions of 1,100 metric tons  (MT) (also referred to as the
“brightline” threshold) or 4.6 MT per service population of carbon dioxide equivalents (CO2e) 11 or 10 Service population is defined as the sum of the number of residents and the number of employees at the development. CO2e is a measurement used to account for the fact that different GHGs have different potential to retain infrared radiation in the atmosphere and contribute to the greenhouse effect.  This potential, known as the global warming potential (GWP) of a GHG, is dependent on the lifetime, or persistence, of the gas molecule in the atmosphere.  For example, one ton of methane (CH
) has the same contrib ution to the greenhouse effect as approximately 23 tons of CO
. Therefore, CH4 is a much more potent GHG than CO2.  Expressing emissions in CO2e takes the contributions of all GHG emissions to the greenhouse effect and converts them to a single unit equiva lent to the effect that would occur if only CO were being emitted.  Source:  BAAQMD.  CEQA Air Quality Guidelines. 2012. Foothill Expressway Operational Improvements 31 Initial Study County of Santa Clara September 2018 more per year, the project would make a cumulatively considerabl e contribution to GHG emissions and result in a significant impact to global climate change.12 The bright -line numeric threshold of 1,100 MT CO e/year is a numeric emissions level , below which a project’s contribution to global climate change would be le ss than cumulatively considerable.  For projects that are above this bright -line cutoff level, emissions from these projects would still be less than cumulatively significant if the annual GHG emissions from the project, as a whole, are less than or equal to 4.6 MT CO e per service population.  Such a result would indicat e that GHG emissions rates are below year 2020 targets contained in Assembly Bill 32, the California Global Warming Solutions Act, which became law in 2006. .7.2 Impact Discussion a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? Construction GHG Emissions GHG emissions during construction of the proposed roadway improvements would be the result of processing and manufact uring construction supplies, operating construction equipment, and construction-related vehicle trips (construction crews, material and equipment deliveries, off hauling demolition debris and soil, etc.).  GHG emissions will be generated at different level s throughout project construction activities.  Construction-related GHG emissions vary depending on the level of activity, duration of the construction, specific construction operations, equipment -type use, and number of construction personnel.  Currently, neither the County, City of Los Altos, nor BAAQMD have adopted GHG significance thresholds that apply to construction projects.  Given the small size of the proposed project and given that the project is located in an urban setting near construction suppl ies, equipment, and workforces, GHG emissions resulting from project -related construction activities would not contribute substantially to local or regional GHG emissions.  For these reasons and because construction GHG emissions would be a temporary condi tion and would not result in permanent ongoing emissions that would interfere with the implementing AB 32, GHG emissions during construction of the proposed project would be less than significant.  (Less Than Significant Impact) Operational GHG Emissions The proposed roadway improvements would not generate new vehicles trips.  The proposed project would reduce vehicle delays on this segment of Foothill Expressway and its intersections with El Monte Avenue and San Antonio Road, which is one of its objective s.  Improving an existing direct travel route through the City of Los Altos would reduce vehicle hours traveled (V HT).  These improvements would, in turn, result in a positive effect on GHG emissions. For these reasons, the proposed roadway improvements would not generate operational GHG emissions that would exceed the BAAQMD significance threshold.  (Less Than Significant Impact) 12 One metric ton = approximately 2,205 pounds. Foothill Expressway Operational Improvements 32 Initial Study County of Santa Clara September 2018 b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? The proposed roadway improvements would not generate new vehicle trips and would reduce vehicle delays.  The proposed operational improvements to an existing direct travel route would not increase daily VMT, and could serve to reduce VMT and associated GHG emissions .  As described above, the construction phase of the project would not generate substantial GHGs and the operational phase would result in a reduction in GHG emissions.  GHG emissions would be below BAAQMD GHG thresholds. These results are co nsistent with the goals and objectives of plans and policies that are designed to reduce GHG emissions. For these reasons, the proposed project would not conflict with an applicable plan, policy, or regulation adopted for the purpose of reducing GHG emissi ons.  (Less Than Significant Impact)
Foothill Expressway Operational Improvements 33 Initial Study County of Santa Clara September 2018
.8 HAZARDS AND HAZARDOUS MATERIALS .8.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one -quarter mile of an existing or proposed school? d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 962.5 and, as a result, will it create a significant hazard to the public or the environment? e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, will the project result in a safety hazard for people residing or working in the project area? 1,11 f) For a project within the vicinity of a private airstrip, will the project result in a safety hazard for people residing or working in the project area? g) Impair implementation of, or physically interfere with, an adopted emergency response plan or emergency evacuation plan? h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? Foothill Expressway Operational Improvements 34 Initial Study County of Santa Clara September 2018
.8.2 Impact Discussion a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? Unlike an industrial use, t he proposed operational improvements to Foothill Expressway would not involve the manufacture, use, or disposal of hazardous materials .  The expressway would, however, be used by a variety of trucks carrying such materials, as has been the case historically and as continues today.  There are no known existing conditions along the project alignment that restrict or preclude trucks and that will not change if the improvements are constructed. Therefore, the degree to which the transport of such materials will continue in the future will be unaffect ed by the project. It is worth noting that all v ehicles operating on public roads are subject to local, s tate, and federal regulations governing the t ransport of hazardous materials, including the Hazardous Materials Transportation Act .  For these reasons , the proposed project would not result in significant hazard to the public or the environment.  (No Impact) b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? Until the early 1990s , lead was commonly added to gasoline. As a result, lead was emitted as a component of motor vehicle exhaust.  Upon being emitted from the exhaust pipes of vehicles, the airborne lead would tend to settle in the soils along roadways.  As a result, s oil sampling along many roadways has found that concentrations of lead exceed applicable thresholds for classification as a hazardous material.  This phenomenon, known as aerially -deposited lead (ADL), is widespread. Because Foothill Expressway was built prior to the phaseout of lead as a gasoline additive, elevated concentrations of lead are l ikely to be present in the soil along the expressway . Impact HAZ -1:  Grading and excavation activiti es associated with the proposed roadway improvements could expose construction workers and nearby sensitive receptors to ADL . (Significant Impact) The following measure would be implemented to reduce and/or avoid significant impacts related to possible soil contamination within the road alignment to a less than significant level. MM HAZ -1:  As part of project development, a soil investigation will be conducted to determine whether ADL and other toxins of concern have affected soils that will be excavated as part of the proposed project.  The testing shall be completed in accordance with a workplan prepared by Santa Clara County Roads and Airports Department Environmental Health and Safety Compliance Specialist .  The work plan shall identify the sampling l ocations and methods and the analytical testing to be completed.  The analytical results will be compared against applicable hazardous waste criteria.  Based on 13 Lead is a heavy metal that is found in many products.  Lead is poisonous to humans.  It is especially toxic to the nervous system, although it can adversely effect many systems and organs.  Starting in the 1970s, lead has been removed from certain products such as paint and gasoline in order to reduce the potential for chronic exposure. Foothill Expressway Operational Improvements 35 Initial Study County of Santa Clara September 2018 analytical results, the investigation will provide recommendations regarding management and disposal of affected soils, if present.  The recommendations shall be implemented by the project.  Examples of such recommendations include, but are not limited to, the preparation and implementation of a Health and Safety Plan to safeguard workers who would handle or be exposed to ADL and other toxins of concerns, BMPs to limit exposure to the public, and/or the transport of contaminated soil to an appropirate facility for disposal. With implementation of the mitigation measure identified above, the potenti al for the proposed road alignment to expose construction workers and nearby sensitive receptors to ADL would be reduced to a less than significant level.  (Less Than Significant Impact With Mitigation Incorporated) c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one -quarter mile of an existing or proposed school? The southern boundary of the project at the intersection of Foothill Expressway and El Monte Avenue is approximately 0.15 miles south of Covington Elementary School and two preschools .  As discussed in Section 4.3 Air Quality , the project would temporarily generate air pollutants in the form of TACs and fugitive dust during the construction period.  I mplementation of the Basic Construction Mitigation Measures Recommended for All Projects identified in the BAAQMD CEQA Air Quality Guidelines would reduce air pollutant emissions to a less than significant level. As discussed above, shallow surface soil within the alignment could contain elevated levels of ADL. Disturbance of these soils during construction could cause lad to become airborne.  The proposed project , however, includes MM HAZ -1 to avoid potential ADL impacts to sens itive receptors. Implementation of these mitigation measure s would also reduce hazardous materials impacts to nearby s chools to a less than significant level.  (Less Than Significant Impact with Mitigation Incorporated ) d) Be located on a site which is included on a list 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? Section 65962.5 of the Government Code requires the California Environmental Protection Agency
(CalEPA) to develop and update (at least annually) a list of hazardous waste and subst ances sites. This list is used by the State, local agencies, and developers to comply with CEQA requirements. The list includes hazardous substance release sites identified by the Department of Toxic Substances Control (DTSC) and the State Water Resources Control Board (SWRCB). Based on a search of the State regulatory databases (i.e., Geotrac ker databases managed by SWRCB, a list of solid waste disposal sites identified by SWRCB, a list of “ active” Cease and Desist Orders and Cleanup and Abatement Orders managed by the SWRCB, Envirostor managed by DTSC, and a list of hazardous waste facilities subject to corrective action identifie d by DTSC), the project site is not listed on the hazardous waste or substances sites updated annually per Section 65962.5 of the Foothill Expressway Operational Improvements 36 Initial Study County of Santa Clara September 2018 Government Code.14 The proposed project , therefore, would not result in impac ts related to hazardous materials sites compiled pursuant to Government Code Section 65962.5.  (No Impact) e )  Result in a nearby airport -related safety hazard for people residing or working in the project area? The proposed project is not located in proximity to a n airport.  The nearest airport is the Moffett Federal Airfield, located approximately 4.5 miles northeast of the project site.  Palo Alto Airport, a general aviation facility, is located approximately 5.8 miles north of the site.  Norman Y. Mineta San José International Air port is located approximately 10 miles east of the project site.  The project site is n ot located within the Airport Influence Area (AIA) of any of these airports, which is a composite of the areas surrounding an airport that are affected by noise, height, and safety considerations. For these reasons, implementation of the proposed project would not result in safety hazard impacts due to airport activities.  (No Impact) f) Result in a private airstrip -related safety hazard for people residing or working in the project area ? The project area is not located near a private airstrip and, therefore, would not result i n related impacts. (No Impact) g)  Impair implementation of, or physically interfere with, an adopted emergency response plan or emergency evacuation plan? The proposed project would improve traffic operations and relieve conge stion on a 0.25-segment of Foothill Expressway, thereby improving emergency vehicle response times within the project area. Therefore, the proposed project would not impair or interfere with the implementation of any e mergency response or evacuation plan. (No Impact) h) Expose people or structures to a significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? The proposed roadway improvements are located within a developed urban area that is not designated a wild fire hazard zone.
(No Impact) .8.3 Conclusion The proposed project , with implementation of mitigation measure MM HAZ -1, would not result in significant hazards or hazardous mater ials impacts.  (Less Than Significant Impact with Mitigation Incorporated ) 14 Cal EPA.  “Cortese List Data Resources.” Accessed May 7, 2019.  Available at:
https://calepa.ca.gov/sitecleanup/corteselist/
. 15 Sources: 1) Santa Clara County Airport Land Use Commission, Moffett Federal Airfield Comprehensive Land Use Plan. November 2, 2012.  Figure 3- 17.  2) Santa Clara County Airport Land Use Commission.  P alo Alto Airport Comprehensive Land Use Plan. Figure 3-15.  3) Santa Clara County Airport Land Use Commission. Norman Y.  Mineta San José International Airport Comprehensive Land Use Plan.  November 2016. CalFire.  Very High Fire Hazard Severity Zones .  October 8, 2008. Foothill Expressway Operational Improvements 37 Initial Study County of Santa Clara September 2018
.9 HYDROLOGY AND WATER QUALITY
.9.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checkl ist Source(s)
Would the project: a) Violate any water quality standards or waste discharge requirements? b) Substantially deplete groundwater supplies or 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)? c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a st ream or river, in a manner which will result in substantial erosion or siltation on -or off- site? d) Substantially alter the existing drainage 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? 1,13 e) Create or contribute runoff water which will exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff? f) Otherwise substantially degrade water quality? g) Place housing within a 100-year flood hazard area as mapped on a Federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? 1,14 h) Place within a 100-year flood hazard area structures which will impede or redirect flood flows? 1,14 i) Expose people or structures to a significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? 1,15 j) Inundation by seiche, tsunami, or mudflow? 1 Foothill Expressway Operational Improvements 38 Initial Study County of Santa Clara September 2018 .9.2 Impact Discussion a) Violate any water quality standards or waste discharge requirements? The propos ed roadway improvements would not generate wastewat er or otherwise result in waste discharge impacts.  (No Impact) b) Substantially deplete groundwater supplies or 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)? There are no g roundwater recharge facilities (sometimes referred to as “percolation ponds”) located within the project footprint. The proposed roadway improvements would not utilize or otherwise deplete groundwater supplies . As discussed under checklist question e), the proposed project would incrementally increase impervious surfaces .  The incremental increase in impervious surfaces resulting from the project would not substantially i nterfere with groundwater recharge .  (Less Than Significant Impact) c) Substantially alter the existing drainage 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? The project area is relatively flat.  The proposed project would not include the construction of new buildings or structures and therefore would not alter existing drainage patterns in the project area. Runoff from the proposed roadway improvements would continue to enter to existing stormwater drain age system serving the project area as it does under existing conditions.  The proposed roadway improvements would occur within the existing developed right -of-way, and are not located within an area subject to the hydromodification management requirements . As noted previously, there are no creeks or waterways located within or adjacent to the project footprint. For all of these reasons, the project would not alter the existing drainage pattern of the area and would not result in substantial on- or off-site erosion or siltation.  (No Impact) d) Substantially alter the existing drainage 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 m anner which will result in flooding on-or off -site? The proposed roadway improvements would not alter existing drainage pattern s in the project area. Runoff from the proposed roadway improvements would continue to enter to existing stormwater 17 Santa Clara Valley Urban Runoff Pollution Prevention Program.  “HMP Applicability Map Cities of Los Altos and Los Altos Hills.”  Accessed: December 4, 2017.  Available at: http://www.scvurppp -w2k.com/hmp_maps.htm
. Foothill Expressway Operational Improvements 39 Initial Study County of Santa Clara September 2018 drainage system serving the project area.  As discussed under checklist question e), runoff generated by the proposed project would be treated onsite prior to discharging to the existing stormwater drainage system, reducing both the rate and volume of stormwater runof f.  For these reasons, the proposed project would not result in flooding on or off the site.  (No Impact) e) Create or contribute runoff water which will exceed the capacity of existing or planned stormwater drainage systems or provide substantial additi onal sources of polluted runoff? Construction Construction of the proposed roadway improvements would result in temporary impacts to surface water quality by generating dust, litter, oil, and other pollutants that could contaminate runoff from the site. Construction activities would also result in the disturbance of underlying soils, thereby increasing the potential for erosion and sedimentation. The proposed project would disturb more than one acre of soil and, therefore, would be subject to the Natio nal Pollutant Discharge Elimination System ( NPDES) Construction General Permit.  Per the requirements of the NPDES Construction General Permit  (CGP), the project would implement the standard measures listed below to reduce impacts to water quality from construction activities. Standard Measures: The following standard measures would be implemented in conformance with federal and State requirements: ●  The County will prepare and file Notice of Intent with the San Francisco Bay Regional Water Quality Control Board and a Storm Water Pollution Prevention Program (SWPPP) will be prepared.  The certified SWPPP shall be posted along the project a lignment and will be updated as necessary to reflect current site conditions and shall include the following: ● BMPs, as specified in the California Storm Water Best Management Practice Handbook, shall be implemented (such as silt fences/straw waddles around the perimeter of the site, regular street cleaning, temporary cover of disturbed surfaces, and inlet protection) to re duce water quality impacts from construction activities. ● Erosion- and dust -control measures shall be implemented during construction and all adjacent streets shall be kept free of dirt and mud during construction.  All vegetation in disturbed areas will b e replanted as quickly as possible, and all trucks hauling soil or other loose materials will be covered and/or at least two feet of freeboard shall be maintained. Post-Construction The 0.25- mile segment of Foothill Expressway to be improved by the propos ed project currently contains 262,700 square feet of impervious surfaces.  The proposed roadway improvements would increase impervious surfaces within the project alignment by approximately 22,770 square feet
(approximately 8.6 percent increase) to a total of 285,470 square feet of impervious surfaces, incrementally increasing the amount of stormwater runoff generated. The project would add or replace more than 10,000 square feet of impervious surfaces and, therefore, would be required to Foothill Expressway Operational Improvements 40 Initial Study County of Santa Clara September 2018 comply with NPDES Municipal Regional Permit (MRP), which provides enhanced performance standards for the management of stormwater of new development .  In conformance with the MRP, the project would implement the standard measures listed below. Standard Measures: The following standard measures would be implemented in conformance with federal and State requirements:

• During the final design of the project , the County will develop details of specific BMPs, including, but not limited to, bioswales and landscaping to provide filtering and reduce impervious surface area.

• All post -construction Treatment Control Measures ( TCMs) will be hydraulically sized to tre at all runoff from the roadway, in accordance with County of Santa Clara numeric sizing criteria for pollutant remova l treatment systems.

• All TCMs will be installed, operated, and maintained by qual ified personnel.  On-site inlets will be stenciled in conformance with County requiremen ts and cleaned out a minimum of once per year, prior to the wet season. The proposed project, with implementation of the standard measures listed above and in compliance with the NPDES CGP and MRP, would not violate water quality standards or waste discharge requirements, c reate or contribute runoff water which will exceed the capacity of existing or planned stormwater drainage systems , or provide substantial additional sources of polluted runoff.  (Less Than Significant Impact) f) Otherwise substantially degrade water quality? As discussed under checklist question e), construction and operation of the proposed roadway improvements with implementation of standard measures and in compliance with the NPDES CGP and MRP , would not violate water quality standards or waste discharge requirements, create or contribute runoff water which will exce ed the capacity of existing or planned stormwater drainage systems, or provide substantial additional sources of polluted runoff.  The refore, the proposed project would not otherwise substantially degrade water quality.  (No Impact) g)  Place housing wit hin a 100-year flood hazard area as mapped on a Federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? The proposed project does not propose housing and, therefore, would not place housing within a 100-year flood hazard area.  (No Impact) h) Place within a 100-year flood hazard area structures which will impede or redirect flood flows?
Foothill Expressway Operational Improvements 41 Initial Study County of Santa Clara September 2018 Based on floodplain maps prepared by the Federal Emergency Management Agency (FEMA), t he project site is not located within a 100-year flood hazard area.  T herefore, the proposed project would impede or redirect flows within 100-year flood hazard area. 18  (No Impact) i) Expose people or structures to a significant risk of loss, injury or death involving flooding, including fl ooding as a result of the failure of a levee or dam? The proposed roadway improvements are not located within a dam failure inundation area, or area subject to flooding due to levee failure . Therefore, the proposed project would not expose people or structures to flooding as a result of the failure of a levee or dam .  (No Impact) j)  Result in inundation by seiche, tsunami, or mudflow? The project site is not located near a lake or other body of water that is subject to a seiche.  The project site is n ot subject to inundation from a tsunami, The project site is relatively flat and is not subject to mudflows.  The refore, the proposed project would not be affected by these hazards..  (No Impact) 18 Federal Emergency Management Agency.  “Flood Insurance Rate Map.”  P arcel 06085C0201H.  May 2009. Accessed: March 29, 2018.  Available at:
https://msc.fema.gov/portal/search?AddressQ uery=foothill%20expressway%20and%20el%20monte%20avenue%2 C%20los%20altos#searchresultsanchor.  19 Sources: 1) Santa Clara Valley Water District.  Anderson Dam Inundation Map.  2016.  2) Santa Clara Valley Water District.  Lenihan (Lexington) Dam Flood Indun dation Maps.  2016. Foothill Expressway Operational Improvements 42 Initial Study County of Santa Clara September 2018
.10 LAND USE AND PLANNING .10.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Physically divide an established community? 1 b) Conflict with any applicable land use plan, 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? 1,16 c) Conflict with any applicable habitat conservation plan or natural community conservation plan? .10.2 Impact Discussion a) Physically divide an established community? The proposed project includes roadway improvements to a 0.25 -mile segment of Foothill Expressway located in the City of Los Altos.  The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road.  The proposed project would not create a physical barrier that would divide an established community. (No Impact) b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project adopted for the purpose of avoiding or mitigating an environmental effect? The proposed project is identified in the voter -approved 2016 Mea sure B, Expressway Program.  The roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road and, therefore, would not conflict with existing or future land use. For these reasons , the project would not conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project adopted for the purpose of avoiding or mitigating an environmental effect.  (No Impact ) c )  Conflict with any applicable habitat conservation plan or natural community conservation plan? The proposed roadway improvements would occur within the existing developed right -of-way of Foothill Expressway and El Monte Road. The project is not located within boundaries of a habitat or Foothill Expressway Operational Improvements 43 Initial Study County of Santa Clara September 2018 natural community conservation plans. The proposed project would not conflict with an applicable habitat or natural community conservation plan.  (No Impact)
Foothill Expressway Operational Improvements 44 Initial Study County of Santa Clara September 2018
.11 NOISE AND VIBRATION The following discussion is based, in part, on an Environmental Noise Assessment prepared by Illingworth & Rodkin, Inc.  in April 2018.  A copy of this report is included in Appendix A of this Initial Study. .11.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impa ct No Impact Checklist Source(s)
Would the project result in: a) Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? 1,17,18,1 b) Exposure of persons to, or generation of, excessive groundborne vibration or groundborne noise levels? 1,17 c) A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project? 1,9,17,18
,19 d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project? 1,17,18,1 e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, will the project expose people residing or working in the project area to excessive noise levels? 1,11 f) For a project within the vicinity of a private airstrip, will the project expose people residing or working in the project area to excessive noise levels? CEQA does not define what noise level increase would be considered substantia l.  The following criteria, based on standards identified in the County’s General Plan and the City of Los Altos General Plan and Municipal Code
, were used to evaluate the significance of environmental noise resulting from the project: 20 There are various descriptors of noise used in these general plans.  Leq stands for the Noise Equivalent Level and is a measurement of the average energy level intensity of noise over a given period of time such as the peak commute ho ur.  Ldn stands for Day -Night Level and is a 24 -hour average of noise levels, with a 10 -dB penalty applied to noise occurring between 10 PM and 7 AM.  CNEL stands for Community Noise Equivalent Level; it is similar to the Ldn except that there is an additi onal 5-dB penalty applied to noise that occurs between 7 PM and 10 PM. Foothill Expressway Operational Improvements 45 Initial Study County of Santa Clara September 2018

• A significant noise impact would be identified if the project would expose persons to or generate noise levels that would exceed applicable noise standards presented in the General Plan s or Municipal Code; or

• A significant impact would be identified if the construction of the project would expose persons to excessive vibration levels.  Ground-borne vibration levels exceedin g 0.3 inches per second (in/sec) Peak Particle Velocity (PPV) wo uld have the potential to result in cosmetic damage to normal buildings ; or

• A significant impact would be identified if traffic generated by the project or project improvements/operations would: a)  result in an increase of three dBA community noise equivalent level ( CNEL) or greater at noise -sensitive land uses where existing or project noise levels w ould exceed the noise level considered satisfactory for the affected land use, or b) an increase of five dBA CNEL or greater at noise -sensitive land uses where noise levels woul d continue to be below those considered satisfactory for the affected land use ; or

• A significant noise impact would be identified if construction activities are predicted to occur more than one year at noise -sensitive receiver locations and exceed 60 dBA L eq and ambient noise levels by five dBA L eq or more. County of Santa Clara General Plan The County of Sa nta Clara’s General Plan sets forth noise and land use compatibility standards for proposed land uses in the Health and Safety section.  The Count y establishes 55 dBA Ldn as the noise level limit that is compatible with residential and 60 dBA Ldn for educational land uses.  The County also establishes 65 dBA Ldn as the noise level limit that is compatible with recreational and dBA Ldn for commerc ial land uses.  General Plan Policy C -HS(i) states that construction shall be prohibited in areas which exceed applicable interior and exterior standards, unless suitable mitigation measures can be implemented. City of Los Altos General Plan The City of L os Altos General Plan sets forth noise and land use compatibility standards for proposed land uses.  General Plan Policy 7.2 establishes 60 dBA CNEL as the maximum acceptable outdoor noise exposure level for single -family residential areas and 65 dBA CNEL or less as the maximum acceptable outdoor noise exposure level for multi -family residential areas.  General Plan Policy 7.4 requires a project to consider the potential impact on the general noise level when planning changes and improvements to the circula tion system. City of Los Altos Municipal Code The City’s Municipal Code regulates the noise levels of any fixed sources of disturbing, excessive or offensive sounds or noises on adjacent noise sensitive land uses.  Section 6.16.070 of the Municipal Code limits the operation of any tools or equipment used in construction, drilling, repair, alteration, or demolition work adjacent to residential properties to between the hours of 7:00 AM and 5:30 PM on weekdays and between 9 AM and 3 PM on Saturdays, with no noise generating construction allowed on Sundays or the City -observed holidays of New Year’s Day, Memorial Day, Independence Day, Labor Day, Veteran’s Day, Thanksgiving Day and Christmas Day.  Where technically and Foothill Expressway Operational Improvements 46 Initial Study County of Santa Clara September 2018 economically feasible, construction activities, including mobile and stationary equipment, shall be limited to a maximum of 75 dBA in residential districts all other times and days. .11.2 Impact Discussion a) Result in exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? Construction Construction of the proposed project would generate noise level exceeding the City’s 75 dBA L max criteria where nearby residential receptors are not shielded by existing noise barriers.  As discussed above, a construction noise impact would be significant if noise level standards are exceeded more than one year.  Since construction is anticipated to take approximately six months and noise levels at indiv idual receptors wo uld decrease as construction activities progress along the alignment, the project would not result in significant construction impact s.  Further, project construction activities would be limited to the hours specified in the City of Los Altos Municipal Code and the standard noise construction noise avoidance measures listed below would be implemented by the project . Standard Measures: The project shall implement the following standard construction noise reduction measures:

• Limit noise -producing signals, including horns, whistles, alarms, and bells, to safety warning purposes only;

• Equip all internal combustion engine -driven equipment with intake and exhaust mufflers that are in good condition and appropriate for equipment;

• Unnecessary idling of internal combustion engines should be strictly prohibited;

• Locate stationary noise -generating equipment, such as air compressors or portable power generators, away from sensitive receptors ;

• If stationary -noise generating equipment must be located near receptors, a dequate muffling
(with enclosures where feasible and appropriate) shall be used to reduce noise levels at adjacent sensitive receptors ;

• Utilize “quiet” air compressors and other stationary noise sources where technology exists;

• Construction staging areas shall be established at locations that will create the greatest distance between the construction -related noise sources and adjacent noise-sensitive receptors;

• Control noise from construction worker radios to a point where they are not audi ble at adjacent residences;

• Designate a “disturbance coordinator” who would be responsible for responding to construction noise complaints.  The disturbance coordinator will determine the cause of the noise complaint (e.g., bad muffler, etc.)  and will req uire that reasonable measures be implemented to correct the problem.

• Post the telephone number for the disturbance coordinator at conspicuous locations on the construction site and include the telephone notice sent to neighbors regarding the construction schedule. Foothill Expressway Operational Improvements 47 Initial Study County of Santa Clara September 2018 Based on the applicable noise thresholds, project -generated construction noise would not be significant.  In addition, l imiting construction hours as s pecified in the Municipal Code and implementing the standard measures described above would further reduce construction-related noise impacts.  (Less Than Significant Impact ) Operation The proposed roadway improvement s include adding one auxil iary lane to Foothill Expressway in each direction between San Antonio Road and El Monte Avenue, a second right -turn lane on southbound Foothill Expressway , and a second through lane on westbound El Monte Avenue.  The project would also square the northeast, northwest, and southwest corner of t he El Monte Avenue intersection and add pedestrian sensors a t the intersection. There is an existing nine foot t all noise barrier on the west side of Foothill Expressway. Noise measurements were taken along the alignment to determine ambient noise levels. The primary noise source at all measured locations was traffic utilizing Foot hill Expressway. Based on the noise measurements, ambient noise levels along the project alignment range from 56 to 69 CNEL. According to the City’s General Plan, a significant impact would occur if the permanent noise level increase due t o project-generated noise was three dBA CNEL or greater at noise -sensitive land uses where existing or project noise levels exceed 60 dBA CNEL.  Based on estimated future traffic volumes, the noise level increase attributable the proposed roadway improveme nts is calculated to be approximately one dBA CNEL .  The noise level increase would be less than the City’s three dBA CNEL threshold.  (Less Than Significant Impact) b) Result in exposure of persons to, or generation of, excessive groundborne vibration or gr oundborne noise levels? Vibration generated from vehicle traffic along the proposed roadway improvements is anticipated to be below 0.01 in/sec PPV, which is below the threshol d of 0.3 in/sec PPV at nearby structures. Project construction, which is anti cipated to take approximately six months, may generate perceptible vibration during heavy equipment or impact tool  (e.g., jackhammers, hoe rams, etc.) use.  At a distance of 20 feet, however, vibration levels from the various types of equipment anticipated to be used during construction of the proposed roadway improvements would be below the 0.3 in/sec PPV threshold.  In addition, vibration levels at individual receptors would decrease as construction activities progress along the alignment and project cons truction activities would be limited to the hours specified in the City of Los Altos Municipal Code.  For these reasons, vibration levels during construction of the proposed roadway improvements would not result in a significant impact.  (Less Than Signifi cant Impact ) c) Result in a substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project? Based on noise measurements taken along Foothill Expressway in the project area, ambient noise levels alo ng the project alignment range from 56 to 69 CNEL.  Based on estimated future traffic volumes, the noise level increase attributable to the proposed roadway improvements is calculated to be approximately one dBA CNEL.  This noise level increase would be less than the threshold of Foothill Expressway Operational Improvements 48 Initial Study County of Santa Clara September 2018 three dBA CNEL and, therefore, is not considered a substantial permanent noise increase.  (Less Than Significant Impact) d) Result in a substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project The improvements would generate noise exceeding the City’s 75 dBA L max criteria where nearby residential receptors are not shielded by existing noise barriers.  As discussed above under checklist question a), constructi on of the proposed roadway improvement s is estimated to take less than one year (approximately six months) to complete, and construction noise levels at individual receptors would decrease as construction progresses along the roadway alignment.  With imple mentation of the standard measures listed under checklist question a ), the project would not result in a substantial temporary increase in ambient noise levels in the project vicinity.  (Less Than Significant Impact) e) For a project located within an airpor t land use plan, or where such a plan has not been adopted, w ithin two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels ? As discussed in Section 4.8 Hazards and Hazardous Materials , the proposed project is not located with in an airport land use plan or within two miles of an airport .  (No Impact) f) For a project within the vicinity of a private airstrip, would the project expose people residing or working i n the project area to excessive noise levels ? As discussed in Section 4.8 Hazards and Hazardous Materials , the proposed project is not located in the vicinity of a private airstrip.  (No Impact)
Foothill Expressway Operational Improvements 49 Initial Study County of Santa Clara September 2018
.12 TRANSPORTATION/T RAFFIC The following discussion is based on an Operational Analysis prepared by Iteris, Inc. in August 18.  A copy of this report is included in Appendix B of this Initial Study. .12.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
Would the project: a) Conflict with an applicable plan, ordinance or 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? 1,9,16 b) Conflict with an applicable congestion 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? 1,9,16 c) Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks? 1,11 d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible land uses (e.g., farm equipment)? 1,9,16 e) Result in inadequate emergency access? 1,9,16 f) Conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities? 1,9,16 Foothill Expressway Operational Improvements 50 Initial Study County of Santa Clara September 2018
.12.2 Impact Discussio n a)  Conflict with an applicable plan, ordinance or 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 co mponents of the circulation system, including but not limited to intersections, streets, highways and freeways, pedestrian and bicycle paths, and mass transit? The proposed project, which is identified in the voter-approved 2016 Measure B, Expressway Pr ogram, proposes improvements to a 0.25-mile segment of Foothill Expressway between El Monte Avenue and San Antonio Road in the City of Los Altos .  As stated previously, the objective of the project is to improve pedestrian, bicycle, and traffic operations.  The proposed improvements include the following:

• Adding an auxiliary lane in each direction on Foothill Expressway between El Monte Avenue and San Antonio Road.

• Adding a 2 nd right turn lane on southbound Foothill Expressway at the Foothill Expressway/ El Monte Avenue intersection.

• Adding a 2 nd through lane on westbound El Monte Ave nue.

• Squaring all corners of the intersection. Similar to existing conditions, t he project would include bike slots and pedestrian sensors at the intersection of Foothill E xpressway/El Monte Avenue. Traffic Operations Impact Methodology Local street performance is measured using the “level of service” (LOS) concept, whereby traffic demand is evaluated in the context of capacity. Since intersections are a key factor in determining the capacity of local streets, local plans focus on AM and PM peak-hour operations at intersections.  The methodology, which is based on the Transportation Research Board’s Highway Capacity Manual , computes a LOS taking into account factors such as the demand for each traffic movement (i.e., left turns, straight, right turns), the number of lanes, and (where applicable) signal timing. Based on these factors, the methodology computes the average delay per vehicle at the intersection using software known as TRAFFIX, to which a corresponding LOS is assigned. LOS can range from “LOS A”, representing free -flow conditions, to “LOS F”, representing jammed/over -saturated conditions.  The City of Los Altos and the County of Santa Clara have established peak-hour LOS goals of D and E, respectively Traffic Operations Impact As shown in Table 4.12-1, Foothill Expressway and El Monte Avenue intersection operations would improve under the proposed project.  T he average delay per vehicle would decrease and inte rsection LOS would improve from LOS E+ to LOS D- during the AM peak-hour and from LOS E- to LOS E during the PM peak-hour. As shown in Table 4.12-2, Foothill Expressway and San Antonio Road intersection operations would improve under the proposed projec t.  The average delay per vehicle would decrease and intersection Foothill Expressway Operational Improvements 51 Initial Study County of Santa Clara September 2018 LOS would improve from LOS E- to LOS E during the PM peak-hour.  The change during the AM peak -hour would be negligible. By adding features such as crosswalks and sensors, as well as squari ng the intersections (which reduce vehicular speeds for turning traffic, enhance pedestrian visibility, and reduce intersection crossing distance ), the proposed project would improve pedestrian, bicycle, and traffic operations in the project area. (No Impact) Table 4.12-1: Foothill Expressway/El Monte Avenue Intersection Operations Peak Hour Scenario Average Delay Per Vehicle Level of Service AM Existing
.2 E+
Existing + Project 53.4 D-PM Existing
.2 E-Existing + Project 63.4 E
Source: Iteris, Inc.  Foothill Expressway Operational Analysis Report.  August 2018.. Table 4.12-2: Foothill Expressway/San Antonio Road Intersection Operations Peak Hour Scenario Average Delay Per Vehicle Level of Service AM Existing
.5 A
Existing + Projec t 9.4 A
PM Existing
.7 E-Existing + Project 71.8 E
Source: Iteris, Inc.  Foothill Expressway Operational Analysis Report.  August 2018. Foothill Expressway Operational Improvements 52 Initial Study County of Santa Clara September 2018 b)  Conflict with an applicable congestion management program, including, but not limited to level of se rvice standards and travel demand measures, or other standards established by the county congestion management agency for designated roads or highways? The Santa Clara Valley Transportation Agency oversees the Congestion Management Program
(CMP) for Santa Clara County.  As discussed above under checklist question a), th e proposed project woul d improve pedestrian, bicycle, and traffic operations in the project area , which is consistent with the goals and objectives of the CMP .  (No Impact) c) Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks? The proposed project would improve the operation of the existing roadway, and would not change or interfere wi th air traffic patterns.  (No Impact) d )  Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible land uses (e.g., farm equipment)? A ll roadway improvement s under the jurisdiction of the County, including the proposed project, are required to adhere to its applicable roadway design standards and regulations , the primary purpose of which is ensuring safe travel for all modes of transportation.  For these reasons, the proposed project would not increase hazards.  (No Impact) e) Result in inadequate emergency access? The proposed roadway improvement s would alleviate congestion and improve the operation of a .25-mile segment of Foothill Expressway, which would improve emergency response times in the project area. (No Impact) f) Conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities? As discussed above under checklist questions a) and d), the proposed project would improve pedestrian, bicycle, and traffic operations and safety along a 0.25-mile segment of Foothill Expressway.  Therefore, the project would not conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities.  (No Impact)
Foothill Expressway Operational Improvements 53 Initial Study County of Santa Clara September 2018
.13 MANDATORY FINDINGS O F SIGNIFICANCE
.13.1 Environmental Checklist Potentially Significant Impact Less Than Significant With Mitigation Incorporated Less Than Significant Impact No Impact Checklist Source(s)
a) Does the project have the potential to degrade 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 pr ehistory? 1-19 b) Does the project have impacts that are individually limited , but cumulatively considerable  (“cumulatively considerable”
means that the incremental effects of a pro ject 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)? 1-19 c) Does the project have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? 1-19 .13.2 Impact Discussion a) Does the project have th e potential to degrade 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 n umber 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? The project would result in temporary impacts to air quality, water quality, and noise during construction.  I mplementation of standard measures identified in the respective sections of this Initial Study, would reduce these temporary construction -related impacts to a less than significant level. Project construction, including tree removal, has the potential to impact nests, eggs, or protected bird species.  I mplementation of mitigation measure MM BIO-1 would avoid impacts to nesting migratory birds and raptors , and trees removed would be replaced consistent with the County’s T ree Preservation Ordi nance. Foothill Expressway Operational Improvements 54 Initial Study County of Santa Clara September 2018 Although unlikely, project construction activities also have the potential to impact unrecorded archaeological and paleontological resources.  Implementation of mitigation measure s MM CUL-1 and MM CUL -2 would reduce these impacts to a less than s ignificant level. The proposed project, with i mplementation of standard measures and mitigation measure s, would not result in significant biological or cultural resource impacts.  (Less Than Significant with Mitigation Incorporated) b) Does the project have impacts that are individually limited, but cumulatively considerable? The potential environmental impacts from the proposed roadway improvement project are primarily limited to the construction period.  Construction of the proposed project is estimated to take up to six months.  Standard measures and m itigation measures are included in the proposed project to reduce impacts to air quality, biology, cultural resources, hydrology and water quality, and hazardous materials impacts during project constructi on to a less than significant level.  Therefore, the proposed project would not contribute to cumulative impacts upon these resources.  (Less Than Significant with Mitigation Incorporated) c) Does the project have environmental effects which will cause subst antial adverse effects on human beings, either directly or indirectly? The proposed project would improve pedestrian, bicycle, and traffic operations and safety along a congested segment of Foothill Expressway.  In addition, with implementation of standard measures and mitigation measures included in the proposed project and described in air quality, biological resources, cultural resources, hydrology and water quality, and hazardous materials sections of this Initial Study, the proposed roadway improvement would not cause significant adverse effects on human beings, either directly or indirectly. Foothill Expressway Operational Improvements 55 Initial Study County of Santa Clara September 2018 Checklist Sources
. Professional Judgement and expertise of the environmental specialist preparing this assessment, based upon a review of the site and surrounding conditions, as well as a review of the project plans.
. Santa Clara County.  Charting a Course for Santa Clara County’s Future: 1995-2010 General Plan.  December 1994.
. Santa Clara County.  Municipal Code.  Available at:
https://library.municode.com/ca/santa_clara_county/codes/code_of_ordinances. . California Department of Transportation.  “California Scenic Highway Mapping System.” Accessed: March 26, 2017.  Available at:
http://www.dot.ca.gov/hq/LandArch/16_livability/scenic_highways/.
. Bay Area Air Quality Management District.  Clean Air Plan 2017.  April 19, 2017.
. Bay Area Air Quality management District.  California Environmental Quality Act Air Quality Guidelines.  May 2017.
. Santa Clara County Roads & Airports Department.  San Tomas Expressway Widening Project Initial Study/Mitigated Negative Declaration.  April 2014.
. County of Santa Clara Roads & Airports Department.  Comprehensive County Expressway Planning Study 2008 Update.  March 2009.
. Iteris, Inc.  Foothill Expressway Operational Analysis Report.  August 23, 2018.
. CalEPA.  “Cortese List Data Resources.” Accessed May 7, 2019.  Available at:
https://calepa.ca.gov/sitecleanup/corteselist/.
. 1) Santa Clara County Airport Land Use Commission, Moffett Federal Airfield Comprehensive Land Use Plan.  November 2, 2012.  Figure 3-17.  2) Santa Clara County Airport Land Use Commission.  Palo Alto Airport Comprehensive Land Use Plan.  Figure 3-
.  3) Santa Clara County Airport Land Use Commission.  Norman Y. Mineta San José
International Airport Comprehensive Land Use Plan.  November 2016.
. CalFire.  Very High Fire Hazard Severity Zones.  October 8, 2008. . Santa Clara Valley Urban Runoff Pollution Prevention Program.  “HMP Applicability Map Cities of Los Altos and Los Altos Hills.”  Accessed: December 4, 2017.  Available at:
http://www.scvurppp-w2k.com/hmp_maps.htm.
. Federal Emergency Management Agency.  “Flood Insurance Rate Map.”  Parcel 085C0201H.  May 2009.  Accessed: March 29, 2018.  Available at:
https://msc.fema.gov/portal/search?AddressQuery=foothill%20expressway%20and%20el%2 monte%20avenue%2C%20los%20altos#searchresultsanchor. . 1) Santa Clara Valley Water District.  Anderson Dam Inundation Map.  2016.  2) Santa Clara Valley Water District.  Lenihan (Lexington) Dam Flood Inundation Maps.  2016.
. Santa Clara County.  “Expressway Plan 2040 Study.”  Accessed: April 17, 2018.  Available at: https://www.sccgov.org/sites/rda/PnS/PS/Expy2040-study/Pages/Expy2040-Study.aspx. . Illingworth & Rodkin, Inc.  Environmental Noise Assessment for Foothill Expressway Operational Improvements Project.  April 4, 2018.
. City of Los Altos.  City of Los Altos General Plan.  November 2002.
. City of Los Altos.  “Code of Ordinances.”  Accessed April 17, 2018.  Available at:
https://library.municode.com/ca/los_altos/codes/code_of_ordinances?nodeId=TIT14ZO. . Bain Research Associates.  Archaeological Resources Assessment – Foothill Expressway between El Monte Avenue and San Antonio Road, Los Altos, Santa Clara County.  February
, 2017. Foothill Expressway Operational Improvements 56 Initial Study County of Santa Clara September 2018
. California Department of Conservation.  Seismic Hazard Zones, Los Gatos Quadrangle . September 23, 2002.
.  California Department of Conservation. Earthquake Fault Zones, Los Gatos Quadrangle . November 1, 1991.
.  United States Department of Agriculture.  “Web Soil Survey.” Accessed: March 28, 2018. Available at:  https://websoilsurvey.nrcs.usda.gov/app/WebSoilS urvey.aspx
. Foothill Expressway Operational Improvements 57 Initial Study County of Santa Clara September 2018 SECTION 5.0 REFERENCES Bain Research Associates.  Archaeological Resources Assessment – Foothill Expressway between El Monte Avenue and San Antonio Road, Los Altos, Santa Clara County.  February 7, 2017. Bay Area Air Quality Management District. California Environmental Quality Act Air Quality Guidelines. 2012. Bay Area Air Quality Management District.  Clean Air Plan 2017.  April 19, 2017. CalEPA.  “Cortese List Data Resources.” Accessed May 7, 2019.  Available at:
https://calepa.ca.gov/sitecleanup/corteselist/. CalFire.  Very High Fire Hazard Severity Zones.  October 8, 2008. California Department of Conservation.  Earthquake Fault Zones, Los Gatos Quadrangle. November 1, 1991. California Department of Conservation.  Seismic Hazard Zones, Los Gatos Quadrangle.  September
, 2002. California Department of Transportation.  “California Scenic Highway Mapping System.”  Accessed:
March 26, 2017.  Available at:
http://www.dot.ca.gov/hq/LandArch/16_livability/scenic_highways/. City of Los Altos.  City of Los Altos General Plan.  November 2002. City of Los Altos.  “Code of Ordinances.”  Accessed April 17, 2018.  Available at:
https://library.municode.com/ca/los_altos/codes/code_of_ordinances?nodeId=TIT14ZO. City of Los Altos.  Historic Resources Inventory.  October 2012. County of Santa Clara Roads & Airports Department.  Comprehensive County Expressway Planning Study 2008 Update.  March 2009. Federal Emergency Management Agency.  “Flood Insurance Rate Map.”  Parcel 06085C0201H. May 2009.  Accessed: March 29, 2018.  Available at:
https://msc.fema.gov/portal/search?AddressQuery=foothill%20expressway%20and%20el%2 monte%20avenue%2C%20los%20altos#searchresultsanchor. Illingworth & Rodkin, Inc.  Environmental Noise Assessment for Foothill Expressway Operational Improvements Project.  April 4, 2018. Iteris, Inc.  Foothill Expressway Operational Analysis Report.  August 23, 2018. Santa Clara County.  Charting a Course for Santa Clara County’s Future: 1995-2010 General Plan. December 1994. Foothill Expressway Operational Improvements 58 Initial Study County of Santa Clara September 2018 Santa Clara County.  “Expressway Plan 2040 Study.”  Accessed: April 17, 2018.  Available at:
https://www.sccgov.org/sites/rda/PnS/PS/Expy2040-study/Pages/Expy2040-Study.aspx
. Santa Clara County.  Municipal Code.  Available at: https://library.municode.com/ca/santa_clara_county/codes/code_of_ordinances
. Santa Clara County Airport Land Use Commission, Moffett Federal Airfield Comprehensive Land Use Plan.  November 2, 2012.  Figure 3-17. Sant a Clara County Airport Land Use Commission.  Norman Y. Mineta San José International Airport Comprehensive Land Use Plan.  November 2016. Santa Clara County Airport Land Use Commission.  P alo Alto Airport Comprehensive Land Use Plan.  Figure 3-15 Santa C lara County Roads & Airports Department. San Tomas Expressway Widening Project Initial Study/Mitigated Negative Declaration.  April 2014 Santa Clara Valley Urban Runoff Pollution Prevention Program.  “HMP Applicability Map Cities of Los Altos and Los Alt os Hills.”  Accessed: December 4, 2017.  Available at:
http://www.scvurppp-w2k.com/hmp_maps.htm
. Santa Clara Valley Water District.  Anderson Dam Inundation Map.  2016. Santa Clara Valley Water Dis trict.  Lenihan (Lexington) Dam Flood Indundation Maps.  2016. United States Department of Agriculture.  “Web Soil Survey.” Accessed: March 28, 2018. Available at:  https://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
. Foothill Expressway Operational Improvements 59 Initial Study County of Santa Clara September 2018 SECTION 6.0 LEAD AGENCY AND CONSULTANTS .1 LEAD AGENCY Santa Clara County Roads and Airports Department Harry Freitas, Director Christine Li, Project Manager .2 CONSULTANTS David J. Powers & Associates, Inc. Environmental Consultants and Planners John Hesler, Principal Project Manager Demetri Loukas, Princi pal Project Manager Amy Wang, Assistant Project Manager Mott McDonald Engineering Services Teferi Abere Basin Research Associates Cultural Resource Services Colin I. Busby Illingworth & Rodkin, Inc. Acoustica l Consultant Manasi Biwalka r Iteris, Inc. Traffic Cons ultants Exhibit B MITIGATION MONITORING AND REPORTING PROGRAM Foothill Expressway Operational Improvements Project County of Santa Clara Roads & Airports Department November 2018 Foothill Expressway Operational Improvements November 2018 Mitigat ion Monitoring and Reportin g Program Page 1 P R E F A C E Section 21081 of the California Environmental Quality Act (CEQA) requires a Lead Agency to adopt a Mitigation Monitoring and Reporting Program whenever it approves a project for which measures have been required to mitigate or avoid significant effec ts on the environment.  The purpose of the monitoring and reporting program is to ensure compliance with the mitigation measures during project implementation. The Foothill Expressway Operational Improvements Initial Study/Mitigated Negative Declaration concluded that the implementation of a project to make improvements to a 0.25- mile segment of Foothill Expressway, between El Monte Avenue and San Antonio Road, in the City of Los Altos, California, could result in significant effects on the environment.  Mitigation measures were incorporated into the proposed project to avoid/reduce these impacts. This document list s all of the mitigation measures, and describes:

• How the measures will be implemented

• Who will implement the m easures

• When the measures will be implemented This document does not discuss those subjects for which the Initial Study concluded that the impacts from implementation of the project would be less -than- significant and for which no measures were incorporated to avoid or minimize impacts. Foothill Expressway Operational Improvements November 2018 Mitigat ion Monitoring and Reportin g Program Page 2 MITIGATION MONITORIN G AND REPORTING PROGRAM FOOTHILL EXPRESSWAY OPERATIONAL IMPROVEM ENTS PROJECT Description of Measure Timeframe for Implementation Responsibility for Implementation Oversight for Implementation BIOLOGICAL RESOURCES : Construction activities and tree removal during the nesting season could result in the loss of fertile eggs, nesting raptors or other migratory birds, or nest abandonment. MM BIO-1: 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 are extends from February 1 through August 31. If it is not possible to schedule construction and tree removal between September 1 and January 31, then pre -construction surveys for nesting birds shall be completed by a qualified ornithologist to ensure no nests are disturbed during project implementation.  This sur vey shall be completed no more than 14 days prior to the initiation of grading, tree removal, or other demolition or construction activities during the early part of the breeding season (February 1 through April 30) and no more than 30 days prior to the in itiation of these activities during the late part of the breeding season (May 1 through August 31). During this survey, the ornithologist shall inspect all trees and other possible nesting habitats within and immediately adjacent to the construction area for nests.  If an active nest is found sufficiently close to work areas to be disturbed by construction, the ornithologist, in consultation with CDFW, shall determine the extent of a construction-free buffer zone to be established around the nest to ensure that nests of bird species protected by the MBTA or Fish and Game code shall not be disturbed during project construction. Prior to construction Roads and Airports Department Roads and Airports Department Foothill Expressway Operational Improvements November 2018 Mitigat ion Monitoring and Reportin g Program Page 3 MITIGATION MONITORIN G AND REPORTING PROGRAM FOOTHILL EXPRESSWAY OPERATIONAL IMPROVEM ENTS PROJECT Description of Measure Timeframe for Implementation Responsibility for Implementation Oversight for Implementation CULTURAL RESOURCES : Although unlikely, unknown cultural resources could be encountered during excavation activities associated with the proposed project. MM CUL-1.1:  Operations shall stop within 50 feet of the find and a qualified professional archaeologist shall be contacted for further review, evaluation, and recommendations consistent with CEQA and County of Santa Clara requirements.  Potential recommendations for t reatment could include collection, recordation, and analysis of any significant cultural materials followed by a professional report and curation of materials with a responsible facility. MM CUL -1.2:  State law shall be followed in regards to the discovery of Native American burials (Chapter 1492, Section 7050.5 to the Health and Safety Code, Sections 5097.94, 5097.98, and 6097.99 of the Public Resources Code).  If the remains are Native American, the Santa Clara County Medical Examiner has two working da ys to examine the remains and must notify the Native American Heritage Commission (NAHC)
within 24 hours, if it is determined that the remains are Native American. The NAHC will immediately appoint a Most Likely Descendant (MLD)
who has 48 hours to provi de recommendations to the land owner for the protection and treatment of the remains.  It is not yet known what type of recovery or treatment action might be recommended by the MLD.  If the descendent does not make recommendations within 48 hours, the County shall reinter the remains in an area of the property, secure from further disturbance.  If the County does not accept the MLD’s recommendations, the County or the MLD may request remediation by the NAHC. During all phases of construction Contractor Roads and Airports Department 1 California law uses the term “Most Likely Descendent” (MLD); that is, an individual recognized by the NAHC as most likely descended from the deceased Native American. Under California law this individual can recommend appropriate treatment of Native American human remains (e.g., in situ pres ervation, exhumation, analyses, report, etc.)
discovered during construction or other activities. Foothill Expressway Operational Improvements November 2018 Mitigat ion Monitoring and Reportin g Program Page 4 MITIGATION MONITORIN G AND REPORTING PROGRAM FOOTHILL EXPRESSWAY OPERATIONAL IMPROVEM ENTS PROJECT Description of Measure Timeframe for Implementation Responsibility for Implementation Oversight for Implementation HAZARDS AND HAZARDOUS MATERIALS:  Grading and excavation activities associated with the proposed roadway improvements could expose construction workers and nearby sensitive receptors to ADL. MM HAZ-1:  As part of project development, a soil investigation will be conducted to determine whether ADL and other toxins of concern have affected soils that will be excavated as part of the proposed project.  The testing shall be completed in accordance with a workpl an prepared by Santa Clara County Roads and Airports Department Environmental Health and Safety Compliance Specialist.  The work plan shall identify the sampling locations and methods and the analytical testing to be completed.  The analytical results will be compared against applicable hazardous waste criteria.  Based on analytical results, the investigation will provide recommendations regarding management and disposal of affected soils, if present.  The recommendations shall be implemented by the project .  Examples of such recommendations include, but are not limited to, the preparation and implementation of a Health and Safety Plan to safeguard workers who would handle or be exposed to ADL and other toxins of concerns, BMPs to limit exposure to the publi c, and/or the transport of contaminated soil to an appropriate facility for disposal. Prior to construction Roads and Airports Department Roads and Airports Department SOURCE: Initial Study/Mitigated Negative Declaration: Foothill Expressway Operational Improvements County of Santa Clara Roads & Airports Department September 2018