EIR CommentsCity of Cupertino
Attn: Aly Chan., Interim City Manager
10300 Torre Avenue
Cupertino, CA 9501.4
City Manager's office
August 30, 2018
Re: Final Environmental Impact Report (EIR) (Draft and Response to
Comments) for the Vallco Special Area Specific Plan Project (File Number
EA -2017-05)
Dear Ms. Chan:
Thank you for the City of Cupertino's response to comments made in the City of
Santa Clara's (CSC) letter. dated July 9,'201.8, regarding the draft
Environmental Impact Report (FIR) for the Vallco Special,Area Specific Plan
Project ("project" ). The CSC and City,of.Cupertino also -met to review the
CSC's concerns with the EIR in terms of new sanitary sewer flows coming into
CSC's system from the project.
As stated in the CSC July 9, 2018, comment letter; "ja]n evaluation of the
sanitary sewer conveyance capacity impacts of this Project to the City of Santa
Clara's sanitary sewer system. is required and the results'of the evaluation
along with the mitigation measures need to be included in the EIR." The City of
Cupertino has yet to conduct this requested evaluation. The` CSC has reviewed
the Response to Comments in the Final EIR, and because this complete
evaluation of the sanitary sewer system has not,been performed, the CSC still
has concerns most notably the following;
1) The likelihood that future flows from the project entering the CSC will
exceed the 13.8 million gallon per day (mgd)'maximum
instantaneous rate of flow set forth in the agreement between the
CSC and the Cupertino Sanitation District (CuSD).
2) The potential that the project will be. constructed without enforceable
mitigation measures in place to address sanitary sewerflows that
exceed the 13.8 mgd maximum instantaneous rate of flow.
Because of these shortcomings in the evaluation of the sewer systems, itis
difficult to fully assess the seweIr ponveyance capacity impacts and we believe
that there could be substantial impacts to the CSC's sanitary sewer system in
the event of full project build out. The, following comments are provided. in
response to the CBC's review of the Response to Comments in the Final EIR:
1500 Warburton Avenue « Santa Clara, CA 95050>- Phone: (408) 815-2210 Fax: (408) 241-6771 � www.santaclaraca.gov
Amy Chan, City Manager
August 30, 2018
Page 2
Comment 1: The Final EIR provides. the following response to the sanitary
sewer comments in CSC's July. 9, 2018, comment letter:.
Response C.2.- The text of mitigation measure UTIL-2.3 has been revised to
clarify the mitigation measures for sanitary sewer impacts downstream of the
project, within the City of Santa Clara. Refer to Section 5.0 (revisions to pages
389-390 of the Draft EIR) and Section 6.0 (revisions to pages 255-256 of the
Draft EIR Amendment) for the text revisions.
The text revisions added (Draft EIR pages 389-390 and Draft EIR Amendment
pages 255-256) still do not adequately address the potential impacts to the
CSC's,,sanitary sewer system. The added text states that, "[t]he existing CuSD
peak wet I weather flow into the Santa Clara system is. modeled at 10.7 mgd.
However, the existing flow. used I in the model is not defined, it is not clear if it is
based on any recent flow monitoring, and whether or not it includes flow from
the recently occupied Apple Campus. The added text also states that,.
"Incorporating estimated sewer generation rates from the project and trom,other
potential projects as established by the General Plan_," however the potential
projects are not defined. Is there a list of these projects? What is the projected
incoming sanitary sewer flow to the CSC system due to these potential
projects? Does the modeled 10.7 mgd flow include the projected , flow from
these potential projects (i.e.,. cumulative impact) as well as' inflow and infiltration
projections?
Comment 2: MM UTIL-2.2 states that future development under the proposed
project shall install new mains of an adequate size determined by CuSD, or
install a parallel pipe of adequate size to the existing 27 -inch sewer main as
determined by CuSD. However, determining whether or not upsizing these
,pipes are required should be evaluated during the EIR process, as it is a
foreseeable consequence of the project. If impacts require up_sizingof these
pipes, the flow to CSC will bealtered. Furthermore, a full evaluation of the
effects of the project on the CSC's sewer system should be finalized before
completing the environmental review process so the extent of the impacts to
the CSC sewer system and necessary mitigations are known.
Comment 3: MM UTI L-2.3 states that, "no certificates of occupancy shall be
issued by the City for structures or units that would result in the permitted peak
wet weather flow capacity of 13.8 mgd through the Santa Clara sanitary sewer
system being exceeded". This language creates the potential that the entire
project will be constructed prior to any necessary mitigation being planned, let
alone installed. An EIR must provide fully enforceable mitigation measures
through permit conditions, agreements, or other legally -binding instruments. A
limitation tied to occupancy permits is inadequate and at:,a minimum, the text of
MM I UTIL-2.3 "no certificate Iof occupancy shall be issued' should be revised to
Amy Chan, City Manager
August 30, 2013
Page 3
"no building permit shall be issued". Connections should not be made into a
sanitary sewer system unless the adequate capacity has been established.
Using the potential withholding of a certificate of occupancy to delay flow that
would exceed capacity is not an adequate mitigation measure.
Comment 4 Final EIR, page 938, revisions to Impact UTL-2; Project — Under
the latest revisions to the EIR several assumptions were made regarding
existing flows and capacity within the CSC sewer system. The section indicates
that existing flows entering the CSC system are 10.7 mgd with an available
capacity of 3.1 mgd. Due to the lack of information it is not clear on how any of
these projections were arrived at and if they are accurate. Furthermore the
section states that "Because the needed capacity is less than the total available
capacity there is adequate sewage capacity between CUSD and the City of
Santa Clara to serve the project and the General Plan Buildout". The CSC has
not received any information from the City of Cupertino or the CuS® to support
this statement so this conclusion lacks the requisite substantial evidence.
This section also states that "If additional hydraulic modeling is performed on.
the CuSD system and the model indicates that the 13.8 mgd contractual limit
through the `City of Santa Clara would be surpassed by the project, the future
developer(s) would not be permitted to occupy any structures or units that
result in the contractual limit being exceeded until additional capacity is
available through the City of Santa Clara's sewer system." This defers the
necessary hydraulic modeling to evaluate the impacts, and does not commit the
City of Cupertino or the Developer to conducting the hydraulic modeling at any
specific time. In addition, as discussed previously, any such modeling should
not be tied to occupancy permits, and at a minimum; this section should be
revised to read, "the future developer(s) would not be granted building
permits...':
Comment 5: Finally, in the second paragraph on page. 939 of the Final EIR,
construction impacts are discussed. However, without an evaluation of the
impacts from the proposed development to the CSC's sanitary sewer system,
the need for improvements cannot be determined. Without this assessment it
is not clear what the construction impactswould be, how they would be
addressed as well as what the necessary mitigations would be.
The CSC maintains that a full sanitary sewer impact analysis is needed to
determine whether or not there are any sanitary sewer conveyance capacity
impacts to the CSC's sanitary sewer system with the buildout of the project.
The Final EIR contains detailed and full analyses related to
traffic/transportation, and water services, but falls short in terms of a full
analysis of the sanitary sewer impacts to the CSC system. As the CSC stated
in the July 9 comment letter and on several other occasions, a full analysis of
the potential impacts and mitigations to the CSC sanitary system is necessary
Amy Chan, City Manager
August 30, 2018
Page 4
as the potential for sanitary sewer overflows cannot be left unresolved.
Additionally the CSC has requested that the total sanitary sewer discharge
information, including the flow generated. from the project, be provided- as CSC
hasoffered to Work: with an on-call engineering sanitary sewer hydraulic
modeling consultant:to perform an analysis. To date, the requested information
has not been provided to CSC.
The City is. requesting that the comments noted above be addressed as part of
the environmental process for the project and that the City of Cupertino -defer
cons l e
'deretf ion.and. certification of the EIR UrItil these issues have'been
addressed. The CSC is available to meet with the City of Cupertinoand discuss
these.1tems further.
Should you have any questions regarding this letter, please contact Andrew
Crabtree, 'Director of Community Development, via email at
acrabtre6gsantaclaraca.gov or by phone at 408-615-2450.
Sincerely,
Deanna J. Santana
City Manager
City of Santa Clara
cc: Santa Clara City Council
Piu Ghosh
Timm Borden