HomeMy WebLinkAboutCC 10-06-2026 Item No. 10 Approved remediation plan for soil contamination at The Rise_Written CommunicationsCC 10-06-2026
#10
Approved remediation plan
for soil contamination at
The Rise
Written Communications
From:Rhoda Fry
To:Public Comments
Cc:City Council
Subject:October 6 Public Comment #10
Date:Saturday, October 3, 2026 6:56:36 PM
Attachments:20260625_req_smp.pdf
20260916_VIMS_Design_approval.pdf
Vallco - Response to Public Inquiries - Mr Lowenthal.pdf
CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you
recognize the sender and know the content is safe.
Dear City Council,
I am grateful that in 2021, Mayor Moore and Vice-Mayor Chao supported having the County
take a look at contaminants at the Vallco site. They have saved countless residents and
workers from illnesses. I am also grateful to the County for their due diligence and for not
caving in to political pressure to rubber-stamping the project. The last attachment is one of
several letters that were directed to the County on this topic.
I hope that they will be discussing both two cases on geotracker and have attached the most
recent letters of each:
Site Cleanup Program Case No. 2022-15s
Site Cleanup Program Case No. 2021-16s
The complete history can be viewed at these sites:
https://geotracker.waterboards.ca.gov/profile_report.asp?global_id=T10000020648
https://geotracker.waterboards.ca.gov/profile_report.asp?global_id=T10000017167
Warm Regards,
Rhoda Fry
County of Santa Clara
Environmental Health
Hazardous Materials Compliance Division 1555 Berger Drive, Suite 300 San José, CA 95112-2716 (408) 918-3400 www.ehinfo.org/hazmat
Board of Supervisors: Sylvia Arenas, Betty Duong, Otto Lee, Susan Ellenberg, Margaret Abe-Koga County Executive: James R. Williams
June 26, 2026 APN 316-20-121
SENT VIA ELECTRONIC MAIL ONLY
Steve McCartt (smccartt@shpco.com)
Vallco Property Owner LLC
2600 El Camino Real, Suite 410
Palo Alto, California 94304
Re: East Vallco Mall Site (Parcel East of Wolfe Road)
10123 North Wolfe Road, Cupertino, CA
Site Cleanup Program Case No. 2022-15s
GeoTracker ID T10000020648
Dear Mr. McCartt:
Santa Clara County Environmental Health (EH) has reviewed the Site Investigation and Updated Conceptual Site
Report (Report) prepared by EKI Environment and Water (EKI) and dated May 5, 2026.
The subject site currently consists of a portion of the former Vallco Mall located east of North Wolfe Road. The
Mall is currently vacant except for the office of Vallco Property Owner, LLC, a bowling alley, an ice rink, and a
Benihana restaurant. A new development is planned for the subject site and will consist of mixed-use residential
and commercial multi-level structures, subsurface parking, and a recreational park. The Report was submitted in
response to the EH directive letter dated April 28, 2025, and includes a conceptual site model (CSM) which
describes the soil, groundwater, and soil vapor conditions at the Site. The results of the site investigation revealed
concentrations of organochlorine pesticides (OCP), volatile organic compounds (VOCs), and metals in soil and/or
soil vapor beneath the Site. The constituents of concern (COC) detected at the site above or equal to their
respective Regional Water Quality Control Board residential, commercial, and/or construction worker
environmental screening levels (ESLs) are chlordane, cobalt, lead and dieldrin in soil; and benzene in soil vapor.
The Report concludes COCs in soil vapor represent a potential vapor intrusion risk to the four planned
developments. Due to the construction timeline, the Report recommends preparation of a site management plan
(SMP) that will include a detailed approach to either mitigate or remediate identified on-site soil and soil vapor
impacts. EH concurs with the Report’s recommendations. In response, you are required to submit a SMP. The
SMP shall include a remedial action plan and mitigation measures based on recommendations presented in the
Report and address data gaps identified in the technical comments below.
TECHNICAL COMMENTS
1. Chlordane, cobalt, lead and dieldrin concentrations in soil exceed the applicable residential and
construction worker direct exposure ESLs, therefore, appropriate precautions to manage soil waste and
East Vallco Mall Site
June 26, 2026
Page 2 of 3
protect worker safety during the planned construction shall be included in the required SMP for proposed
development and as described further below.
2. Detections of chlordane in soil exceeding both residential and commercial ESLs at boring V04, located
adjacent to the active loading dock, are likely attributable to historical operations at the subject site.
Detections of lead in soil exceeding residential ESLs at boring V09, located adjacent to the former
oil/water separator near the former JC Penney, is also likely attributed to a historical release at the Site.
The vertical and lateral extent of soil impacted with chlordane and lead is not defined. The SMP shall
include a soil sampling plan to define the vertical and lateral extent of chlordane and lead in soil that
exceeds ESLs and a remedial excavation plan to remove and dispose of impacted site soil based on the
recommendation of the Report.
3. Based on the data from the CSM, a SMP is required to include construction of each of the four
developments.
a. The SMP shall address all COCs in soil and soil vapor that exceed their respective RWQCB
residential, commercial, and/or construction worker ESLs.
b. The SMP shall include the status of the project’s entitlement with the City of Cupertino, a current
and detailed project description, and the proposed development plan for the subject site in relation
to site-specific COCs and known areas of contamination.
c. The SMP shall include combined historical data tables and figures showing all sample locations
on site. The tables shall include the dates the samples were collected.
d. The SMP shall include proposed plans to manage, mitigate, and/or remediate potential risks
associated with known areas of contamination; for example, procedures for soil excavation and
confirmation soil sampling, dust control measures, waste management and disposal
requirements, potential soil import requirements, and required actions in the event that previously
unidentified areas of contamination and/or hazards are encountered during redevelopment. The
SMP shall include the name of the entity responsible for managing each of the mitigation and/or
remediation measures, requirements, and/or actions.
e. The SMP shall include an evaluation of the need for a VIMS; and if necessary, a conceptual
VIMS design. Following EH concurrence of a conceptual VIMS design, a separate and detailed
VIMS Design and Construction Quality Assurance Plan will be required.
REQUIRED SUBMITTALS
Please submit the following technical documents to EH (Attention: Ms. Shalom Marquardt) according to the
following schedule.
Site Management Plan – Due by September 28, 2026
Technical reports are required pursuant to our authority under Section 101480 of the California Health and Safety
Code. Each report shall include conclusions and recommendations for the next phases of work required to protect
water resources, human health and safety, and the environment at the site. All required work shall be performed
in a prompt and timely manner. Revisions to the schedule shall be requested at least two (2) weeks prior to the
due date in writing with appropriate justification for the anticipated delays and a proposed revised schedule.
East Vallco Mall Site
June 26, 2026
Page 3 of 3
The California Business and Professions Codes (Sections 6735,7835, and 7835.1) require work plans and
technical or implementation reports containing geologic or engineering evaluations and/or judgments must be
performed under the direction of an appropriately registered or certified professional.
PERJURY STATEMENT
All proposals and reports submitted to this office must be accompanied by a cover letter from the Responsible
Party which states, at a minimum, the following:
"I declare, under penalty of perjury, that the information and/or recommendations contained in
the attached proposal or report is true and correct to the best of my knowledge."
This letter must be signed by an officer or legally authorized representative of the Responsible Party. Future
submittals without the required Responsible Party perjury statement may be denied as insufficient.
ELECTRONIC DATA SUBMITTAL REQUIREMENTS
The Electronic Reporting Regulations (Chapter 30, Division 3 of Title 23 & Division 3 of Title 27, CCR) require
electronic submission of any report and data required by a regulatory agency for a cleanup site. You are required
to complete electronic data submittal over the Internet to the case file established for the subject site in the State
Water Resources Control Board (SWRCB) GeoTracker database. Once a report and data are successfully
uploaded, as required, you have met the reporting requirement (i.e., the compliance measure for electronic data
submittal are the actual uploads themselves).
Analytical data (including geochemical data) for all soil, vapor, and water samples that are collected for the
purpose of subsurface investigation or remediation are required to be submitted in specified EDF format to
GeoTracker. Groundwater, soil, and vapor samples include, but are not limited to, monitoring well samples,
borehole samples, gas and vapor samples, groundwater grab samples, piezometer samples, stockpile samples, and
samples from drinking water wells. Other electronic data submittal requirements include boring logs and well
screen intervals, depth to water data, locational data, elevation data, and site maps. For additional details, please
visit please visit the following GeoTracker Reporting Requirements webpage:
www.waterboards.ca.gov/water_issues/programs/ust/electronic_submittal/report_rqmts.
Future reports submitted without accompanying electronic data submittals will be considered incomplete and may
be denied. Please be advised that EH may not close your case without this complete information. If you have any
questions, please feel free to contact me at (408) 918-1943 or via email.
Sincerely,
Shalom Marquardt, PG
Senior Hazardous Materials Specialist
Site Cleanup Program
shalom.marquardt@deh.sccgov.org
cc: Frank Stillo (fstillo@ekiconsult.com)
File – GeoTracker
County of Santa Clara
Environmental Health
Hazardous Materials Compliance Division 1555 Berger Drive, Suite 300 San José, CA 95112-2716 (408) 918-3400 www.ehinfo.org/hazmat
Board of Supervisors: Sylvia Arenas, Betty Duong, Otto Lee, Susan Ellenberg, Margaret Abe-Koga County Executive: James R. Williams
September 16, 2026 APN: 316-20-122
Vallco Property Owner, LLC SENT VIA ELECTRONIC MAIL ONLY
c/o Reed Moulds (rmoulds@shpco.com)
2600 El Camino Real, Suite 410
Palo Alto, CA 94304
Re: Vallco Town Center, 10123 North Wolfe Road, Cupertino, CA
Site Cleanup Program Case #2021-16s
Parcel West of Wolfe Road
GeoTracker ID No. T10000017167
Dear Mr. Moulds:
Santa Clara County Environmental Health (EH) has received the Basis of Design Report for the Vapor
Intrusion Mitigation System Design The Rise – Block 5 (VIMS Design and CQA Plan) prepared by West
Environmental Services & Technology, Inc., (West) and dated September 11, 2026. The VIMS Design and
CQA Plan was submitted in support of the planned mixed-use development at Block 5 only.
A vapor intrusion mitigation system (VIMS) is currently planned to be installed under the footprint of the
building to mitigate potential vapor intrusion from a volatile organic compound soil vapor plume located
on the subject site. The VIMS consists of a vapor intrusion barrier and a sub-slab ventilation layer to be
installed below the concrete slab of the planned development which includes a multi-story mixed-use
residential and commercial building with slab-on-grade construction. The eight-story building will have
commercial use on floors 1 -3 and residential units on floors 4-8. The building will not include any
belowground structures (e.g., subsurface parking) other than elevator pits. The vapor barrier will be sealed
at all foundations and utility penetrations to create an air‐tight seal beneath those portions of the building.
The VIMS Design and CQA Plan includes design plans to construct the VIMS, general construction notes
and specifications, a quality assurance/quality control program to be implemented during construction of
the proposed VIMS, and a description of verification sampling and controls to maintain the long-term
integrity of the VIMS. EH conditionally accepts the VIMS Design and CQA Plan with the following
conditions and requirements.
CONDITIONS OF APPROVAL
1. This letter does not modify or relieve any additional requirements specified for this project by the
City of Cupertino.
2. EH conditional approval of the VIMS design plans applies only to the proposed redevelopment
project as shown in the VIMS Design and CQA Plan. If there are changes to the proposed
Vallco Town Center, 10123 North Wolfe Road, Cupertino, CA
September 16, 2026
Page 2 of 4
redevelopment project or to the VIMS design plans, you are required to notify EH in writing, and
you may be required to submit updated VIMS design plans to EH for approval.
3. EH understands that the City of Cupertino is the lead agency responsible for approving the final
building design plans, which shall incorporate the VIMS design plans. EH understands that the City
of Cupertino will not approve the hazardous materials or soil vapor intrusion mitigation aspects of
the VIMS design plans but will review and approve the VIMS design plans as they relate to
applicable building code, fire code, etc. as part of the overall building design plans. Documentation
of the City of Cupertino’s approval of the VIMS design plans as part of the final building design
plans shall be submitted to EH prior to construction of the building foundation. EH understands
that the proposed building design plans, which include a VIMS, were submitted to the City of
Cupertino, prior to EH review. Typically, VIMS design plans are submitted to EH for review and
approval prior to a city’s review. Please be aware that if the VIMS design plans change during the
City of Cupertino’s review process, EH may require updated plans, which may then require
additional approval from the City of Cupertino.
4. In addition to the VIMS Design Engineer (currently, West), any deviations or modifications from
the EH-approved VIMS design plans must be submitted to and accepted by EH and by the City of
Cupertino prior to proceeding with VIMS construction, with the exception noted in Technical
Comment #5.
5. All selected VIMS products and materials shall be compatible with known constituents of concern
identified for the subject site. It is acceptable to select alternate vapor barrier products at a later date
if needed, provided that the alternate vapor barrier products are designed to provide protection from
potential soil vapor intrusion and have similar physical properties as those described in the VIMS
Design and CQA Plan (ex. product thickness, permeation rate or diffusion coefficient, ASTM
testing data, etc.) to achieve the design objectives and design elements described in the VIMS
Design and CQA Plan. Verification of material compatibility shall be provided to EH in the final
completion report. The final completion report and the final VIMS Design and CQA Plan shall
include a detailed description and technical justifications for the final VIMS products selected and
installed.
6. A copy of the VIMS Design and CQA Plan must be reviewed by all applicable contractors prior to
initiating construction activities and must be kept on site and available at all times throughout the
project. The Responsible Party is responsible for ensuring the VIMS Design and CQA Plan is
reviewed and acknowledged by all applicable contractors prior to construction activities.
7. You are required to notify EH at least two weeks prior to the VIMS Preconstruction Meeting with
the general contractor, VIMS installer and VIMS quality assurance/quality control (QA/QC)
inspector so that EH may be present to observe the VIMS Preconstruction Meeting. The VIMS
QA/QC inspector shall provide a list of required inspections to the VIMS Installer and to EH that
must be conducted to ensure the VIMS is installed in substantial accordance with the VIMS design
plans.
8. You are required to notify EH at least two weeks prior to VIMS quality assurance/quality control
(QA/QC) testing so that EH may be present to observe the QA/QC tests.
9. The previous requirement for a land use covenant shall be deferred, pending results of post-
occupancy verification monitoring.
Vallco Town Center, 10123 North Wolfe Road, Cupertino, CA
September 16, 2026
Page 3 of 4
10. Please refer to the EH letter dated July 9, 2026, for a detailed description of all previously assigned
deliverables, which are summarized below. Please note the required submittals which shall be
submitted to and approved by EH prior to building occupancy.
REQUIED SUBMITTALS
You are required to submit the following reports to EH (Attention: Ms. Shalom Marquardt) via GeoTracker
according to the following schedule. EH is providing a list of anticipated future deliverables for planning
and scheduling purposes.
1. Prior to installation of the building foundation:
a. Confirmation of City Approval of Final VIMS Design – Prior to construction of the building
foundation.
b. VIMS Preconstruction Meeting - Two weeks prior to commencement of VIMS Installation
notify EH of VIMS Preconstruction meeting.
c. Notification to EH VIMS QA/QC – Two weeks prior to VIMS Installation notify EH of
VIMS quality assurance/quality control inspection schedule.
2. Following VIMS installation and building construction:
a. VIMS Completion Report – Due within 60 days following completion of all earthwork
activities, VIMS installation, and building envelope construction activities.
b. VIMS OM&M Plan – Following VIMS installation.
c. Pre-Occupancy Verification Sampling Report (Sampling Events 1 and 2) – Following
building completion and prior to building occupancy.
d. Long-Term Verification Sampling Report (Sampling Events 3 and 4) – Within 12 months
following building occupancy.
e. Long-Term Verification Sampling Report (Sampling Event 5) – Within 24 months
following building occupancy.
Technical reports are required pursuant to our authority under Section 101480 of the California Health and
Safety Code. Each report shall include conclusions and recommendations for the next phases of work
required to protect water resources, human health and safety, and the environment at the site. All required
work shall be performed in a prompt and timely manner. Revisions to the schedule shall be requested at
least two (2) weeks prior to the due date in writing with appropriate justification for the anticipated delays
and a proposed revised schedule.
The California Business and Professions Codes (Sections 6735,7835, and 7835.1) require work plans and
technical or implementation reports containing geologic or engineering evaluations and/or judgments must
be performed under the direction of an appropriately registered or certified professional.
PERJURY STATEMENT
Vallco Town Center, 10123 North Wolfe Road, Cupertino, CA
September 16, 2026
Page 4 of 4
All proposals and reports submitted to this office must be accompanied by a cover letter from the
Responsible Party which states, at a minimum, the following:
"I declare, under penalty of perjury, that the information and/or recommendations
contained in the attached proposal or report is true and correct to the best of my
knowledge."
This letter must be signed by an officer or legally authorized representative of the Responsible Party.
ELECTRONIC DATA SUBMITTAL REQUIREMENTS
The Electronic Reporting Regulations (Chapter 30, Division 3 of Title 23 & Division 3 of Title 27, CCR)
require electronic submission of any report and data required by a regulatory agency for a cleanup site. You
are required to complete electronic data submittal over the Internet to the case file established for the subject
site in the State Water Resources Control Board (SWRCB) GeoTracker database. Once a report and data
are successfully uploaded, as required, you have met the reporting requirement (i.e., the compliance
measure for electronic data submittal are the actual uploads themselves).
Analytical data (including geochemical data) for all soil, vapor, and water samples that are collected for the
purpose of subsurface investigation or remediation are required to be submitted in specified EDF format to
GeoTracker. Groundwater, soil, and vapor samples include, but are not limited to, monitoring well samples,
borehole samples, gas and vapor samples, groundwater grab samples, piezometer samples, stockpile
samples, and samples from drinking water wells. Other electronic data submittal requirements include
boring logs and well screen intervals, depth to water data, locational data, elevation data, and site maps. For
additional details, please visit the following GeoTracker Reporting Requirements webpage:
https://www.waterboards.ca.gov/water_issues/programs/ust/electronic_submittal/report_rqmts.html.
If you have any questions, please feel free to contact me at (408) 918-1943 or via email.
Sincerely,
Shalom Marquardt, PG
Senior Hazardous Materials Specialist
Site Cleanup Program
shalom.marquardt@deh.sccgov.org
cc: Peter Krasnoff, WEST (peterk@westenvironmental.com)
Sharon Squire, WEST (sharon@westenvironmental.com)
File – GeoTracker
From:Gaddi, Rochelle
To:Richard Lowenthal
Cc:Kaahaaina, Jennifer; O"Regan, Gerald
Subject:RE: [EXTERNAL] Vallco is stuck
Date:Tuesday, January 25, 2022 3:46:42 PM
Good afternoon Mr Lowenthal,
Thank you for your email below on this important project. To clarify, the application that we received from Vallco
Property Owner, LLC is an application requesting regulatory oversight which mentions soil removal as a possible
option for addressing onsite contamination at the Vallco project. It is not an application to remove soil, as you
indicate below.
The County Department of Environmental Health (DEH) approved this application for regulatory oversight when
we entered into a remedial action agreement last June 2021 with Vallco Property Owner, LLC. We have been
actively working with the Developer since then to establish a comprehensive understanding of the contaminants on
the site that may pose a threat to future residents, workers and visitors. This process takes time to complete
accurately. We need to establish this understanding of the contamination to ensure the proposed abatement and
mitigation plans will be adequate to protect human health. We have completed our review of the most recent data
submitted by the Developer in late December 2021. Last week, we had multiple conversations with the Developer’s
representative to confirm our understanding of the data and their conclusions. We also presented our conclusions
and proposed next steps. A formal directive letter identifying those next steps is in process and due to be issued
within a couple of days. All records related to our oversight of the Vallco Town Center development, including the
anticipated letter upon issuance, are made available on the publicly accessible GeoTracker website – Global ID
T10000017167. They are in the section entitled Site Maps / Documents.
We reviewed the Developer’s documents when we received them, which were not fully submitted until December
22, 2021. We needed these documents to complete our review and the directive letter is forthcoming.
Please let me know if you need additional information.
Regards,
_________________________________
Rochelle Y Gaddi, REHS
Interim Director
Department of Environmental Health
County of Santa Clara
phone: 408 918-3449
fax: 408 258 5891
mail to: rochelle.gaddi@deh.sccgov.org
For More Information on Environmental Health Guidance for Coronavirus visit us at: http://EHinfo.org/coronavirus
NOTICE: This email message and/or its attachments may contain information that is confidential or restricted. It is
intended only for the individuals named as recipients in the message. If you are NOT an authorized recipient, you
are prohibited from using, delivering, distributing, printing, copying, or disclosing the message or content to others
and must delete the message from your computer. If you have received this message in error, please notify the
sender by return email.
-----Original Message-----
From: Richard Lowenthal <richard@lowenthal.com>
Sent: Saturday, January 22, 2022 12:07 PM
To: District1 <District1@bos.sccgov.org>; Chavez, Cindy <Cindy.Chavez@bos.sccgov.org>; Supervisor.Lee
<Supervisor.Lee@BOS.SCCGOV.ORG>; Ellenberg, Supervisor <supervisor.ellenberg@BOS.SCCGOV.ORG>;
Supervisor Simitian <Supervisor.Simitian@bos.sccgov.org>; DEHWEB <DEHWEB@deh.sccgov.org>
Subject: [EXTERNAL] Vallco is stuck
Dear Supervisors and Department of Environmental Health,
I’m writing today because the Vallco soil removal application has been in front of the Department of Environmental
Health for nine months, there has been no action taken, and we need your help to get this project going. Soil
removal is a routine process and this approval has taken far too long, having been initially filed on April 15, 2021.
This prolonged delay is holding up the largest affordable housing project in Northern California as well as the
vibrant community spaces, green space, and destination retail the will be built along with it. On behalf of the
Cupertino community, I urge the Board of Supervisors and DEH to move this application along immediately so that
the contaminated soil can be removed and construction can begin at Vallco.
Thank you for your consideration,
Richard Lowenthal
Former Mayor of Cupertino
Founding CEO of ChargePoint