Public Water Supply Well 429-W1 for the La Mirada System (PWSID: CA190059)

2 Documents in Project


SCH Number
Public Agency
City of La Mirada
Document Title
Public Water Supply Well 429-W1 for the La Mirada System (PWSID: CA190059)
Document Type
NOE - Notice of Exemption
Document Description
Suburban Water Systems (Suburban) is a Public Utility, (California Public Utilities Code Section 216) that owns the La Mirada Water Water System (PWSID: CA190059). Suburban meets water demands in the La Mirada Water System by utilizing multiple sources of supply including groundwater pumped from wells in the Main San Gabriel Basin, the Central Basin, and from purchased water connections from multiple agencies that include local groundwater and imported water sources. Having multiple sources provides reliability for Suburban to meet customer demands in La Mirada if one or more sources is out of service and to change the water supply mix from purchased water or groundwater to reduce cusrnmer costs. The proposed Well 429 W-1 is located within a City of La Mirada Public Works Yard, south of Stage Road behind an established thick hedge that acts as a visual barrier between Stage Road, the Public Works Yard, and the adjacent railroad. The Plant 429 W-1 facilities will consist of a well drilled to 1,400 feet below ground surface with a buried 20-inch diameter stainless steel casing and screen. The surface facilities will include a small concrete well pedestal and pad, a 12-foot by 12-foot chemical storage building for sodium hypochlorite, and a motor control center. A pump-to-waste pipeline for intermittent flushing will be constructed from Well 429-W1 to an existing stormwater inlet that is located along Stage Road, directly northwest of the project site. The raw water from Well 429-W1 will be conveyed via a buried raw water pipeline to Plant 409 to be treated prior to distribution. A very small portion of piping will be exposed to the surface, including but not limited to, the flush line pipe, gate valve, and piping support. Approximately 15 linear feet of ductile iron or steel pipe will be exposed above ground. Construction of Well 429 W-1 will benefit the public in the City of La Mirada by providing Suburban the flexibility to manage water supplies and reduce the use of more expensive imported water. This helps keep water rates more affordable and reduce the amount of greenhouse gases embedded in the treatment and delivery of the water. The public will also benefit from Suburban's ability to fully utilize the existing capacity of the Plant 409 Treatment Plant by treating water from both Plant 409 W-3 and the proposed Plant 429 W-1, which helps spread the cost of this treatment plant over the water produced at the facility which also helps keep water rates more affordable to the public. Suburban's Plant 409, in La Mirada, includes one well, Plant 409 W-3, and a treatment plant for removing inorganic color and arsenic. The Plant 409 Treatment Plant is sized to treat approximately twice the amount of water from the well 409 W-3. Suburban has enough Central Basin Groundwater Rights to extract and treat to the full capacity of the existing Plant 409 treatment plant and is currently unable to utilize all of these rights, and Plant 429 W-1 will help Suburban to use all of its existing water rights. Plant 409 is approximately one third of a mile from Plant 429.

Contact Information

Manuel Munoz
Agency Name
Lead Agency
Job Title
Community Development Director
Contact Types
Lead/Public Agency


La Mirada
Los Angeles
Cross Streets
Stage Road and Castellon Road

Notice of Exemption

Exempt Status
Categorical Exemption
Type, Section or Code
15302. Class 2 (C) and 15303. Class 3
Reasons for Exemption
This project will not result in an expansion of production capacity because the new well, Plant 429 W-1, needs to be treated and will be treated with the existing, unused water rights and unused existing capacity of the Plant 409 Treatment Plant and which, in turn, will offset the existing capacity of imported purchased water connections. The new well facilities will consist of a small number of new small facilities and small structures in and a short distance of water mains and electrical utility extensions and Plant 429 is located in an existing City Public Works Yard located adjacent to an active railroad line.
County Clerk
Los Angeles


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