www.farallonconsulting.com
July 25, 2025
Nick Towstopiat
David J. Powers & Associates, Inc.
1871 The Alameda, Suite 200
San José, California 95126
RE: THIRD-PARTY REVIEW
10857, 10867, 10877, AND 10887 LINDA VISTA DRIVE
CUPERTINO, CALIFORNIA
FARALLON PN: 2481-009.001
Dear Nick Towstopiat:
Farallon Consulting, L.L.C. (Farallon) has prepared this letter to David J. Powers & Associates, Inc (Client) to provide third-party review of two due diligence environmental investigation reports.
SITE LOCATION AND BACKGROUND
The properties addressed in this review are located at 10857, 10867, 10877, and 10887 Linda Vista Drive in Cupertino, California (Santa Clara County Assessor Parcel Numbers [APNs]: 356-06-001, 356-06-002, 356-06-003, and 356-06-004), referred to herein as the Subject Property. Farallon conducted the review work in coordination with David J. Powers & Associates, Inc. The reviews are being conducted to support the California Environmental Quality Act (CEQA) project proposed to be conducted by the Client for the City of Cupertino and is intended to define appropriate mitigation actions for environmental impacts identified for the Plan Area in advance of planned redevelopment activities. The reports are consistent with Cupertino Municipal Code Sections 17.04.040 B and 17.04.050 B.
The two reports reviewed (prepared by the project applicant’s consultant) are:
• A
EI. 2024. Phase I Environmental Site Assessment: 10857, 10867, 10877, and 10887 Linda Vista Drive in Cupertino, California, 95014, AEI Project 482220.
Prepared for Roy Evulich and Angela Evulich. January 10. • AEI. 2023. Limited Phase II Subsurface Investigation Report: 10857, 10867, 10877, and 10887 Linda Vista Drive in Cupertino, California, 95014, AEI Project 482220.
Prepared for Roy Evulich and Angela Evulich. October 18.
David J. Powers & Associates, Inc.
July 25, 2025
www.farallonconsulting.com
The Subject Property contains single-story residential buildings on approximately 2.54 acres of land. The redevelopment project entails demolition of the four existing single-family residences and the development of 51 townhome condominium units across 10, three-story buildings on the Subject Property.
KEY PHASE I ESA FINDINGS
Farallon identified the following pertinent Phase I ESA findings associated with the third- party review:
Recognized Environmental Condition (REC) – Underground Storage Tanks (USTs) A total of up to four USTs were suspected to have been present on the Subject Property. The property owners reported two 560-gallon steel USTs that were installed in 1972. Both tanks were observed on-site and believed to be filled with concrete. Regulatory databases (SWRCB’s SWEEPS and HIST UST listings) indicate up to four USTs, possibly due to administrative duplication or incomplete records. However, a geophysical survey conducted in 2023 (described below) confirmed the presence of only two USTs and no additional tanks or suspected tank anomalies were identified.
The USTs are reportedly abandoned in place and filled with concrete, but no formal closure records or sampling results were found.
Other Environmental Concern (OEC) – Historical Agricultural Use The Phase I ESA noted that historical aerial photographs indicate the Subject Property was previously used for agriculture. Consequently, there is a potential for legacy organochlorine pesticides, arsenic, and lead in shallow soils.
KEY PHASE II FINDINGS
AEI conducted a limited Phase II subsurface investigation. The work included advancing 11 borings and conducting geophysical scanning for USTs and piping. The investigation included the following:
Geophysical Survey
The geophysical survey confirmed the presence of only two USTs (identified on attached Figure 2). Reportedly the geophysical survey detected no additional tanks or suspect piping; however, some buried debris (concrete/wood) was noted.
David J. Powers & Associates, Inc.
July 25, 2025
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Soil Sampling
Soil sampling was conducted near the USTs at depths of 6 and 12 feet below ground surface (bgs) to evaluate for the potential presence of fuel impacts associated with the abandoned-in-place USTs. Additionally, shallow soil sampling at depths of 1.5 feet bgs was conducted for pesticides and metals to evaluate the potential presence of impacts from historical agricultural usage. Locations of the soil samples are included on Figure 2.
A total of eight soil samples were collected from the UST areas during the Phase II investigation:
• Four borings were advanced near the two known USTs:
o SB-1 and SB-2A (adjacent to the western UST); and
o SB-3B and SB-4 (adjacent to the eastern UST).
• From each boring, two samples were collected:
o One at approximately 6 feet bgs (near the bottom of the UST); and o One at 12 feet bgs (below the UST).
Analytes evaluated included total petroleum hydrocarbons as gasoline (TPH-g), as diesel (TPH-d), and as motor oil (TPH-mo), and volatile fuel compounds, including benzene, toluene, ethylbenzene, and xylenes (BTEX). Results (provided in the attached tables) were compared against Environmental Screening Levels
1 (ESLs) and indicated:
• Gasoline (TPH-g): Not detected above reporting limits; • Diesel (TPH-d): Detected up to 12.3 milligrams per kilogram (mg/kg) (well below its Tier I ESL of 260 mg/kg);
• Motor Oil (TPH-mo): Detected at 7.12 mg/kg (well below its ESL of 1,600 mg/kg); and • BTEX compounds (benzene, toluene, ethylbenzene, xylene): Not detected.
AEI concluded that it does not appear that a significant release has occurred from the historical USTs at the Site.
1 Environmental Screening Levels (ESLs) are not cleanup levels, but rather conservative concentrations of chemicals in soil, soil vapor, and groundwater used as screening tools to assess potential environmental concerns at contaminated sites. ESLs help expedite the identification of sites needing further investigation and cleanup, but they are not intended as definitive cleanup goals.
David J. Powers & Associates, Inc.
July 25, 2025
www.farallonconsulting.com
Seven soil samples were collected for analysis for pesticides and metals (arsenic and lead) during the Phase II investigation. The samples were taken from shallow borings SB-5 through SB-11 (Figure 2). Each boring was sampled at a depth of approximately 1.5 feet bgs, below any fill and within the native soil likely impacted by historical agricultural use.
Samples were analyzed for arsenic, lead, and organochlorine pesticides (OCPs). Results (provided in the attached tables) were compared against ESLs and indicated:
• Arsenic: Max = 3.55 mg/kg (within background level of ≤11 mg/kg for SF Bay Area soils);
• Lead: Max = 10.5 mg/kg (well below its ESL of 80 mg/kg for residential properties); • Pesticides (DDT and DDE):
o Detected in three of seven samples;
o p,p-DDE: Max = 0.0278 mg/kg; and
o p,p-DDT: Max = 0.0107 mg/kg.
AEI concluded that arsenic and lead were not detected above the known background level concentrations (arsenic) or applicable Tier I ESL, indicating that neither arsenic nor lead appears to be a significant concern. In addition, OCPs either were not detected above laboratory limits or were detected well below the Residential Direct Exposure ESLs.
SUMMARY OF POTENTIAL CONCERNS FOR DEVELOPERS
Concern Finding Relevance to
Redevelopment
Recommended Next
Step
UST History Two USTs still in
place; unknown
closure
documentation; old
age
Could delay
city/county permits or
trigger regulatory
involvement
Remove USTs with
regulatory oversight;
document clean
closure
Groundwater Not investigated
(low likelihood
based on existing
data set)
Unknown petroleum
plume potential; could
impact vapor intrusion
Conduct limited
groundwater
sampling if local
agencies require
David J. Powers & Associates, Inc.
July 25, 2025
www.farallonconsulting.com
Soil Vapor Not investigated
(low likelihood
based on existing
data set)
Low concern due to no
VOC detections, but
might be requested for
residential reuse
Optional: soil gas
screening for VOCs
to confirm absence
of vapor risk
Buried debris Detected near
garage (likely inert)
May interfere with
development grading
or utility trenching
Include during
geotech phase;
remove if intrusive
construction occurs
Shallow Soil Metals and
pesticides detected
below screening
levels
No concern for
exposure risk or need
for mitigation based on
concentrations
detected
No action necessary
Unknown
Conditions During
Redevelopment
Potential for
encountering
unknown or
deleterious
conditions
Could delay
development if not
properly managed
Prepare a Soil
Management Plan
CONCLUSIONS
Farallon conducted a third-party review of two due diligence environmental investigation reports for the properties located at 10857, 10867, 10877, and 10887 Linda Vista Drive in Cupertino, California to define appropriate mitigations for environmental impacts identified for the Plan Area in advance of planned redevelopment activities. Farallon offers the following conclusions:
• The Phase I and Limited Phase II documents prepared by AEI are generally consistent with the state of the practice regarding environmental investigations. • Data provided in the reports did not contain detections of chemicals indicative of significant environmental impact in the areas sampled as demonstrated by:
David J. Powers & Associates, Inc.
July 25, 2025
www.farallonconsulting.com
o Absence of significant petroleum or VOC contamination in soil around the two abandoned-in-place USTs;
o No elevated lead, arsenic, or pesticide concentrations above background concentrations or screening levels that a regulator would typically require additional action.
• No groundwater was encountered in the borings that extended to 12 feet bgs; and • The geophysical survey did not identify additional structures or UST anomalies that would suggest significant additional contamination sources.
RECOMMENDATIONS
Farallon offers the following recommendations:
• Documented removal of the two USTs should be conducted. Now that property access is available, the formerly abandoned-in-place USTs should be removed and properly disposed of, and the surrounding soils should be assessed through sampling and analytical testing.
• A Soil Management Plan should be developed to establish response measures for addressing unknown subsurface conditions encountered during construction.
LIMITATIONS
The conclusions contained in this report/assessment are based on professional opinions with regard to the subject matter. These opinions have been arrived at in accordance with currently accepted geologic and engineering practices applicable to this location. The conclusions contained herein are subject to the following inherent limitations:
• Accuracy of Information. Farallon obtained, reviewed, and evaluated certain information used in this report/assessment from sources that were believed to be reliable. Farallon’s conclusions, opinions, and recommendations are based in part on such information. Farallon’s services did not include verification of its accuracy or authenticity. Should the information upon which Farallon relied prove to be inaccurate or unreliable, Farallon reserves the right to amend or revise its conclusions, opinions, and/or recommendations.
For the foregoing reasons, Farallon cannot and does not warrant or guarantee that the Site is free of hazardous or potentially hazardous substances or conditions, or that latent or
David J. Powers & Associates, Inc.
July 25, 2025
www.farallonconsulting.com
undiscovered conditions will not become evident in the future. Farallon’s observations, findings, and opinions can be considered valid only as of the date of the report.
This report/assessment has been prepared in accordance with the contract for services between Farallon and David J. Powers & Associates, Inc. No other warranties, representations, or certifications are made.
Reliance by third parties is prohibited. This report/assessment has been prepared for the exclusive use of David J. Powers & Associates, Inc. to address the unique needs of David J.
Powers & Associates, Inc. at a specific point in time. The City of Cupertino is recognized as an intended user of this report/assessment, subject to the same limitations as David J.
Powers & Associates, Inc.
This is not a general grant of reliance. No one other than David J. Powers & Associates, Inc. may rely on this report unless Farallon agrees in advance to such reliance in writing. Any unauthorized use, interpretation, or reliance on this report/assessment is at the sole risk of that party and Farallon will have no liability for such unauthorized use, interpretation, or reliance.
CLOSING
Farallon appreciates the opportunity to provide environmental consulting services for this project and trusts that this letter provides sufficient information for your needs. Please contact the undersigned at (714) 421-1740 if you have questions or comments.
Sincerely,
Farallon Consulting, L.L.C.
Martin Hamman P.G.
Principal Geologist
Attachment: Selected figure and table from AEI Phase II report MH:cm
wwwww
1.800.801.3224
www.aeiconsultants.com
1.800.801.3224
www.aeiconsultants.com
Limited Phase II Subsurface
Investigation Report
REPORT DATE: October 18, 2023
SITE INFORMATION
10857, 10867, 10877, and 10887 Linda Vista Drive
Cupertino, California 95014
PROJECT INFORMATION
AEI Project No. 482220
PREPARED FOR
Roy Evulich and Angela Evulich
Co-Trustees of the Evulich Living Trust dated
7-8-1980, as amended.
13616 Surrey Ln Saratoga, California 95070
Barris J Evulich and Sondrea Evulich
Co-Trustees of the Evulich 2000 Family UTD Trust
dated October 3, 2000, as amended.
2451 Fairway Village Drive, Park City, Utah, 84060
PREPARED BY
AEI Consultants
2500 Camino Diablo
Walnut Creek, California 94597
LEGEND
SITE MAP
FIGURE 2
Project No. 482220
10857; -67; -77; and -87
LINDA VISTA DRIVE
CUPERTINO, CALIFORNIA 95014
Approximate Site Boundary
Abandoned UST
Soil Boring Location
Shallow Soil Sample Location
0 30 60
SCALE: 1” ~ 60’
Temporary Well Point
Monitoring Well
Soil Boring
SB-1
Proposed Soil Gas Sample Location
Hydraulic Lift
Oil/Water Separator
Floor Drain
UST
Estimated Groundwater Flow Direction
STREET AVENUE ROAD BOULEVARD
SB-9
SB-10
SB-11
SB-4
SB-6
SB-7
SB-5
SB-8
SB-1
SB-2
SB-3
SB-1
10857
10877
10887
10867
TABLE 1: SOIL SAMPLE DATA SUMMARY - TPH AND VOCS
10857; -67; -77; and -87 Linda Vista Drive, Cupertino, California 95014 Total Remaining
Location Depth TPH-g TPH-d TPH-mo Benzene Toluene Ethylbenzene Xylenes VOCs ID Date (feet bgs) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) SB-1 9/19/2023 5-6 <100 12.3 <5.0 <0.0098 <0.0098 <0.0098 <0.0186 <RL SB-1 9/19/2023 11-12 <100 3.07 <5.0 <0.018 <0.018 <0.018 <0.036 <RL SB-2 9/19/2023 5-6 <100 4.84 <5.0 <0.014 <0.014 <0.014 <0.028 <RL SB-2 9/19/2023 11-12 <100 3.22 <5.0 <0.013 <0.013 <0.013 <0.026 <RL SB-3 9/19/2023 5-6 <100 6.26 7.12 <0.013 <0.013 <0.013 <0.026 <RL SB-3 9/19/2023 11-12 <100 4.83 <5.0 <0.0090 <0.0090 <0.0090 <0.018 <RL SB-4 9/19/2023 5-6 <100 2.66 <5.0 <0.011 <0.011 <0.011 <0.022 <RL SB-4 9/19/2023 11-12 <100 5.53 <5.0 <0.014 <0.014 <0.014 <0.028 <RL Comparison Values:
ESL- Tier 1 100 260 1,600 0.025 3.2 0.43 2.1 Various
Notes:
mg/kg milligrams per kilogram
<RL less than the laboratory reporting limit
bgs below ground surface
TPH-g Total Petroleum Hydrocarbons as Gasoline
TPH-d Total Petroleum Hydrocarbons as Diesel
TPH-mo Total Petroleum Hydrocarbons as Motor Oil
VOCs Volatile Organic Compounds
Comparison Values:
ESL Tier 1: Environmental Screening Levels (ESLs) showing Tier 1 (most conservative) exposure risks from July 2019 (Rev. 2) ESL Summary Tables, prepared by the San Francisco Bay Regional Water Quality Control Board AEI Project No. 482220 Page 1 of 1 AEI Consultants
TABLE 2: SOIL SAMPLE DATA SUMMARY - ARSENIC, LEAD, AND PESTICIDES 10857; -67; -77; and -87 Linda Vista Drive, Cupertino, California 95014 Remaining
Location Depth Arsenic Lead p,p-DDE p,p-DDD p,p-DDT Dieldrin Pesticides ID Date (feet bgs) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) SB-5 9/19/2023 1-1.5 2.75 6.85 0.00645 <0.0020 0.00563 <0.0020 <RL SB-6 9/19/2023 1-1.5 3.55 10.2 <0.0020 <0.0020 <0.0020 <0.0020 <RL SB-7 9/19/2023 1-1.5 3.16 7.05 <0.0020 <0.0020 <0.0020 <0.0020 <RL SB-8 9/19/2023 1-1.5 2.89 10.5 <0.0020 <0.0020 <0.0020 <0.0020 <RL SB-9 9/19/2023 1-1.5 2.58 7.40 <0.0020 <0.0020 <0.0020 <0.0020 <RL SB-10 9/19/2023 1-1.5 3.19 8.25 0.0278 0.00240 J 0.0107 0.00129 J <RL SB-11 9/19/2023 1-1.5 2.67 8.55 0.00469 <0.0020 0.00272 <0.0020 <RL Comparison Values:
ESL- Tier 1 0.067 1
32 0.33 2.7 0.0011 0.00046 Various
ESL Direct Exposure - R 0.067 1
80 1.8 1.8 1.9 0.037 Various
Notes:
mg/kg
<RL
bgs
DDE
DDD Dichlorodiphenyldichloroethane
DDT
1 Arsenic concentrations from Establishing Background Arsenic in Soil of the San Francisco Bay Region, December 2011 study indicate background levels of arsenic in California Bay Area soil typically range between 1.2 and 11 mg/kg.
J Indicates a value between the method MDL and PQL and that the reported concentration should be considered as estimated.
Comparison Values:
ESL Tier 1: Environmental Screening Levels (ESLs) showing Tier 1 (most conservative) exposure risks from July 2019 (Rev. 2) ESL Summary Tables, prepared by the San Francisco Bay Regional Water Quality Control Board ESL Direct Exposure - R: Environmental Screening Levels (ESLs) showing Direct Exposure Human Health Residential (R) Use exposure risks from July 2019 (Rev. 2) ESL Summary Tables, prepared by the San Francisco Bay Regional Water Quality Control Board milligrams per kilogram
less than the laboratory reporting limit
below ground surface
Dichlorodiphenyldichloroethylene
Dichlorodiphenyltrichloroethane
AEI Project No. 482220 Page 1 of 1 AEI Consultants