HomeMy WebLinkAboutCD 2025-0005; CARLSBAD DESALINATION PLANT; BRINE DISCHARGE TECHNOLOGY EMPIRICAL STUDY; Admin Decision LetterMarch 26, 2025
Ms. Michelle Peters
Chief Operating Officer
Channelside Water Resources+
4590 Carlsbad Blvd
Carlsbad, CA 92008
( Cicyof
Carlsbad
SUBJECT: CD2025-0005 (DEV2022-0139) -CARLSBAD DESALINATION PLANT; BRINE DISCHARGE
TECHNOLOGY EMPIRICAL STUDY
Dear Ms. Michelle Peters
The City Planner has competed a review of your application for Consistency Determination, CD 2025-
0005, pursuant to Planning Department Administrative Policy 35, Discretionary Permit Consistency
Determinations. Because CMC Chapter 21.89 is not in effect within the Coastal Zone at the time of this
letter's creation, Policy 35 is used to determine substantial conformance. Further, Policy 35 is
referenced in the Precise Development Plan PDP00-02(F) as the appropriate process for review of minor
modifications to the desalination plant.
CD 2025-0005 proposes temporary and minor modifications to the Carlsbad Desalination Plant to
facilitate a study on the survival rates of plankton travelling through the new desalination intake system.
The study will require: partially submerged intake and discharge sampling pipes and hoses
(approximately four inches in diameter), two barrel samplers (one each for intake and discharge
samples, each approximately four feet in diameter), a temporary mobile laboratory (within a truck
trailer), and associated appurtenances. The sampling pipes will connect study equipment to the lagoon
and discharge pond. Four to eight technicians will be needed to conduct the research associated with
the Brine Discharge Technology Empirical Study (Study). Study conclusions may result in future
adjustments to the intake and discharge systems.
Noise generated by the water pumps used during the three days of field sampling per month will
commensurate or less than existing noise generated on site and no noise is expected from the MRPC
(Marine Research Portable Container) operations. Sampling will occur 3 days per month over a 12-
month period. All associated activity with the Study will end within 13 months.
The city originally approved the desalination plant in 2006 and amended that approval in 2009. Those
applications associated with the amended approval are EIR 03-05(A), PDP 00-02(B), SP 144(J), DA 05-
0l(A), RP 05-12(A) and HMP 05-0l(A). Since the 2009 approval, PDP 00-02(B) was further amended to
PDP 00-02(F), SP 144 was repealed, and EIR 03-05 has had several addendums and a supplemental EIR.
Review of this project was aided by an Eighth Addendum supplemented by a January 2025 technical
memorandum prepared by Miller Marine Science & Consulting.
Community Development Department
Planning Division I 1635 Faraday Avenue I Carlsbad, CA 92008 I 442-339-2600
CD 2025-0002 -CARLSBAD DESALINATION PLANT BRINE DISCHARGE TECHNOLOGY STUDY
March 26, 2025
Pa e 2
As a part of the operations of the Carlsbad Desalination Plant {CDP), environmental monitoring
requirements were put into place by the California State Water Resou rces Control Board. The
desalination plant has been monitoring the environmental impacts of its operations since it began
operation in 2015 . When the plant began operations, it was designed and constructed assuming co -
location with the Encina Power Station {EPS) where the EPS seawater once-through-cooling system
would be used to supply the CDP with feedwater and dilution water for mixing with the CDP's brine. The
seawater volumes circulated by the EPS were well in excess of the CDP needs. To comply with the 2010
Statewide Policy on the Use of Coastal and Estuarine Waters for Power Plant Cooling (OTC Policy), the
EPS ceased operation in 2018. In order to continue operations without relying on EPS seawater, the CDP
installed new fish-friendly pump stations in June 2020 {CD 2019-0010, previously approved by the city)
and built a new intake structure, completed in December 2024 (Attachment l){CD 2022-0022, CUP
2022-0010, and SUP 2022-0006, all previously approved by the city). San Diego Regional Water Quality
Control Board {RWQCB) Order R9-2019-0003, amended by Order R9-2020-0004 and Order R9-2023-
0137 (collectively, the Order) requires the execution of a Study no later than 60 days following startup of
the new intake structure.
The purpose of the modifications as considered by CD 2025-0005 is to facilitate an environmental study
to assess the impacts of the new intake structure and associated outfall systems of the Carlsbad
Desalination Plant in Agua Hedionda Lagoon. Project features are generally within the boundaries of the
former EPS, are southeast of the former Carlsbad Aquafarm, and are within a small portion of the lagoon
and near the shoreline. The project street address is 4590 Carlsbad Blvd.
In order for a Discretionary Permit Consistency Determination to be approved, all of the following
findings must be made:
1) No project condition, feature, facility or amenity is changed or deleted that had been considered
essential to the project's design, quality, safety or function in that the Study and its accompanying
activity will not remove any existing equipment or change any regular operations of the CDP.
2) The request represents an upgrade in overall design features and or materials and improves upon the
project's compatibility with surrounding neighborhoods in that the Study is a permit requirement per
Order R9-2019-0003, as amended by Order R9-2020-0004 and Order R9-2023-0137, implemented by
the California State Water Resources Control Board in order to quantify plankton mortality caused by
transit through the brine dilution system. The execution of the Study will help maintain compatibility
with state regulations by fulfilling environmental monitoring requirements and ensuring impacts on
marine life are as anticipated.
3) The proposed revision does not change the density or boundary of the subject property in that the
proposed temporary facility will operate within the established boundary of the existing facility and
will include a small Marine Research Portable Container (MRPC) that will be placed approximately 200
feet from Agua Hedionda Lagoon on existing paved area. The MRPC measures approximately 53 ft 9 in
long, 9 ft 6 in wide, and 13 ft 6 in tall. The temporary operations are a fraction of the size of
permanent operations, are operationally similar to existing operations and therefore would not be
recognized as different from the perspective of the general public. The MRPC will only temporarily
take up about six parking spaces within an area that is not open to the public and has alternative
Community Deve lopment Department
Planning Division I 1635 Faraday Avenue I Carlsbad, CA 92008 I 442-339-2600
CD 2025-0002-CARLSBAD DESALINATION PLANT BRINE DISCHARGE TECHNOLOGY STUDY
March 26, 2025
Pa e 3
available space for parking for MPRC technicians as well as both the CDP and temporary city Fire
Station.
4) The proposed revision does not involve the addition of a new land use not shown on the original
permit in that the proposed temporary pilot project supports the existing land use as a desalination
plant and complies with monitoring requirements per the California State Water Resources Control
Board. The additional equipment required for this testing would not be indicative of a fundamentally
different land use. The site would be similar in appearance before, during and after the Study.
5) The proposed revision does not rearrange the major land uses within the development in that the
Study will operate without disrupting current operations. The size of development supporting the
Study is also a fraction of the size of the permanent facility. There will not be any rearrangement of
the major land uses within the development in order to accommodate the temporary operations. The
project's minor underwater components (hoses, pipes and filters used for sampling) will also not
interfere with other operations in Agua Hedionda Lagoon.
6) The proposed revision does not create changes of greater than ten percent provided that compliance
will be maintained with the applicable development standards of the Carlsbad Municipal Code in that
the temporary pilot project will only consist of a 540 square foot trailer and moveable pieces of
testing equipment, which represent about 0.2% of the estimated existing property area of over six
acres. Additionally, the activities associated with the Study are consistent with those associated with
current operations.
7) The proposed change will not result in any significant environmental impact, and/or require
additional mitigation in that the onshore container will be placed on a developed site and the footprint
of the temporary facility is small (about 540 square feet). Environmental impacts associated with
installation and operation of the Study will be less than significant as documented by Addendum 8
Supplement to EIR which includes a thorough analysis of potential environmental impacts as well as
monitoring and quality control measures consistent with Regional Water Quality Control Board Order
R9-2020-0005. The project is also consistent with the project description analyzed in the Supplement
to the Final EIR (2015091060) certified by the San Diego County Water Authority in August 2016, and
in the Eighth Addendum to the Final EIR dated January 2025.
8) The proposed change would not result in any health, safety or welfare impacts in that the temporary
trailer (MRCP) used for the Study project is largely consistent with the standard current operations of
the CDP. The project is consistent with the project description analyzed in the Supplement to the Final
EIR {SCH#2004041081 and 2015091060} certified by the San Diego County Water Authority in August
2016, and in the Eighth Addendum to the Final EIR dated January 2025. The project is also consistent
with Regional Water Quality Control Board Order R9-2020-0005.
9) There were not any major issues or controversies associated with the original project which would be
exacerbated with the proposed change in that the project is only a temporary study that would not
alter impacts to the environment or community but will instead only monitor the survival rate of
plankton passing through the intake and discharge systems.
Community Development Department
Planning Division I 1635 Faraday Avenue I Carlsbad, CA 92008 I 442-339-2600
CD 2025-0002 -CARLSBAD DESALINATION PLANT BRINE DISCHARGE TECHNOLOGY STUDY
March 26, 2025
Pa e 4
10) The proposed change would not be readily discernable to the decision makers as being substantially
different from the project as originally approved in that the temporary testing project is ancillary to the
desalination plant and is intended to monitor environmental impacts of the Brine Discharge
Technology. The pilot project is similar in appearance to existing operations, and its location and small
size mean that there will not be a noticeable change at the site from the perspective of the general
public. Furthermore, the Study will last 12 months and the MRPC and all related sampling equipment
will be removed from the site within approximately 30 days after the last field sampling event is
complete.
Therefore, the City Planner has determined that the application qualifies for a consistency
determination with the approved permit and approves the changes to the project based on Planning
Division Administrative Policy No. 35.
If you have any questions regarding this matter, please feel free to contact your project planner, Alex
Patterson, at 442-339-5149.
CITY OF CARLSBAD
Re:~-~
Principal Planner
AA:cf
Attachments:
1. Project Description
2. 8th Addendum to EIR
c: Eric Lardy, City Planner
Scott Donnell, Senior Planner
Alex Patterson, Project Planner
Laserfiche/File Copy
Data Entry
Community Development Department
Planning Division I 1635 Faraday Avenue I Carlsbad, CA 92008 I 442-339-2600