Joint Regional Water Supply System Joint Transmission Main - Unit 3 Reach 5 Air-Vacuum Valve Relocations
Summary
SCH Number
2025111154
Public Agency
South Coast Water District
Document Title
Joint Regional Water Supply System Joint Transmission Main - Unit 3 Reach 5 Air-Vacuum Valve Relocations
Document Type
NOE - Notice of Exemption
Received
Posted
11/26/2025
Document Description
The South Coast Water District proposes to relocate three existing Joint Regional Water Supply System (JRWSS) air-vacuum relief valves that are currently in underground vaults, where they have the potential to flood, to aboveground locations next to or in the vicinity of the existing vaults, consistent with current JRWSS standards.
Operations staff would then be able to access the air-vacuum valves for inspection, maintenance, and replacement without entering a confined space. The existing underground vaults and air-vacuum piping connections to the water transmission mains would remain in place. The air-vacuum piping would be extended from the existing water transmission mains, penetrating each vault through a core-drilled hole, and then connected to the new aboveground air-vacuum relief valves.
Construction activities at each location would require excavation to a depth of 3 to 5 feet below ground surface and result in a total disturbed area of approximately 300 square feet. All excavation and land disturbance activities would take place within the existing right-of-way of Alicia Parkway in the City of Laguna Niguel (Figure 1, Project
Sites) and on land that was previously disturbed to construct the existing pipeline, vaults, and street improvements.
We understand that construction would likely occur sometime between April and October 2025. The three vaults would be constructed in sequence with construction periods ranging from three to five days with a maximum of eight trucks required at each site, totaling 20 trips. All three sites will require lane closures and will be scheduled to occur outside of peak commuting hours. The project sites are all within existing roadway with no impact to any trees or other biological resources and would require only shallow excavations (maximum of 5 feet) into previously disturbed soils.
Contact Information
Name
Vernon Weisman
Agency Name
South Coast Water District
Job Title
Capital Program Manager
Contact Types
Lead/Public Agency
Phone
Email
Location
Cities
Laguna Niguel
Counties
Orange
Regions
Citywide, Countywide
Cross Streets
Alicia Parkway
Notice of Exemption
Exempt Status
Categorical Exemption
Type, Section or Code
Section 15301, Existing Facilities - Class 1(b)
Reasons for Exemption
The proposed project is categorically exempt under the “Class 1” categorical exemption (CE), Existing Facilities, as outlined in Section 15301 of the California Environmental Quality Act (CEQA) Guidelines. “Class 1” exemptions consist of operation, repair, maintenance, permitting, leasing, licensing, or minor alteration of existing public or private structures, facilities, mechanical equipment, or topographical features, involving negligible or no expansion of existing or former use. The key consideration is whether the project involves an expansion of use. One of the
examples included under Section 15301 of the CEQA Guidelines is as follows: “Existing facilities of both investor and publicly owned utilities used to provide electric power, natural gas, sewerage, or other public utility services.”
The proposed project involves the minor alteration of publicly owned utility (South Coast Water District) equipment (air-vacuum relief valves) involving no expansion of use.
County Clerk
Orange
Attachments
Notice of Exemption
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