Oso Creek Water Reclamation Plant Improvement Project

2 Documents in Project


SCH Number
Lead Agency
Santa Margarita Water District
Document Title
Oso Creek Water Reclamation Plant Improvement Project
Document Type
MND - Mitigated Negative Declaration
Present Land Use
Water Reclamation Plant
Document Description
The proposed project will consist of demolishing the existing 3.0 million gallon a day (MGD) Oso Creek WRP, existing office and warehousing buildings and constructing a new technologically advanced WRP that is able to treat 3.3 MGD and a 1.0 MGD Oso Barrier Urban Return Water Treatment Plant (URWTP) advanced water treatment facility. Replacement offices, warehousing space, meeting space and parking will also be constructed on the site. The proposed Oso Creek WRP will treat wastewater generated within the SMWD service area and produce tertiary water that meets State of California Title 22 recycled water requirements for unrestricted reuse. The Oso Barrier URWTP will process urban runoff to be used for irrigation, lake fill, and potable reuse. The URWTP will include prescreening equipment, ultrafiltration, reverse osmosis and UV disinfection. The backwash water will be discharged to the Oso Trunk Sewer for treatment and ultimate disposal from the Latham Water Treatment Plant.

Contact Information

Don Bunts
Agency Name
Santa Margarita Water District
Contact Types
Lead/Public Agency / Project Applicant


Mission Viejo
Cross Streets
La Paz Road /Marguerite Pkwy
Total Acres
State Highways
Fred Newhart Middle School
oso creek

Notice of Completion

State Review Period Start
State Review Period End
State Reviewing Agencies
California Air Resources Board (ARB), California Department of Conservation (DOC), California Department of Parks and Recreation, California Department of Transportation, District 12 (DOT), California Department of Water Resources (DWR), California Highway Patrol (CHP), California Native American Heritage Commission (NAHC), California Natural Resources Agency, California Regional Water Quality Control Board, San Diego Region 9 (RWQCB), Department of Toxic Substances Control, Office of Historic Preservation, State Water Resources Control Board, Division of Drinking Water, State Water Resources Control Board, Division of Drinking Water, District 8, State Water Resources Control Board, Division of Water Rights, State Water Resources Control Board, Divison of Financial Assistance, California Department of Fish and Wildlife, South Coast Region 5 (CDFW)
State Reviewing Agency Comments
California Department of Fish and Wildlife, South Coast Region 5 (CDFW)
Development Types
Water Facilities (Replacement of and existing WRP)(Type WRP, MGD 3.3)
Local Actions
Project Issues
Biological Resources, Cultural Resources, Geology/Soils


Draft Environmental Document [Draft IS, NOI_NOA_Public notices, OPR Summary Form, Appx,]
Notice of Completion [NOC] Transmittal form
State Comment Letters [Comments from state reviewing agencies]

Disclaimer: The Governor’s Office of Planning and Research (OPR) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at state.clearinghouse@opr.ca.gov or via phone at (916) 445-0613. For more information, please visit OPR’s Accessibility Site.

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