129th Street Manganese Treatment Plant Project


SCH Number
Public Agency
State Water Resources Control Board
Document Title
129th Street Manganese Treatment Plant Project
Document Type
NOE - Notice of Exemption
Document Description
Golden State Water Company - Southwest proposes to upgrade its existing water system, at the specified project location listed above, to resolve issues of manganese and dissolved oxygen to help meet water quality compliance. This will be accomplished by addition of a 1,250 gallon-per-minute manganese removal treatment system, a 44,000-gallon backwash recovery tank, a 33,000-gallon baffled pressure contact vessel, a 3,000-liter liquid-oxygen (LOX) storage tank, and LOX feed system with concrete pad. The backwash water is discharged into the tank within the system and will not be discharged into any storm or sewer system. The accumulated concentrated sludge from the tank is pumped out into a truck and hauled away to a disposal facility. The purpose of the LOX is to increase the dissolved oxygen (DO) of the water to match that of the imported Metropolitan Water District surface water. The project will be constructed on an existing facility within an existing building and outer area of the building. The entire facility resides within an urbanized residential area.

Contact Information

Adrian Dela Calzada
Agency Name
State Water Resources Control Board
Job Title
Environmental Scientist
Contact Types
Lead/Public Agency


Los Angeles
Southern California
Cross Streets
2931 W. 129th Street,

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
Class 1 Existing Facilities (California Code of Regulations, Title 14, Division 6, Chapter 3, Article 19, Section 15301)
Reasons for Exemption
The Project is minor additions to an existing facility. The Project involves minimal expansion of use beyond that existing facility at the time of the lead agency’s determination.
County Clerk
Los Angeles


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.

Download CSV New Search Print