Lift Station No. 2 Replacement

Owner:

South Coast Water District

Location:

Laguna Beach, California

Value:

$34.4 million

Completion:

Projected 2026

Contractor:

J.R. Filanc Construction Company

Butier Engineering, Inc. (Prime) is providing constructability review, construction management, and field inspection services for this project. The Lift Station 2 Replacement project is adjacent to a resort and golf course and is 100 feet north of Aliso Creek and 700 feet east of Pacific Coast Highway. Lift Station 2, which was constructed in 1953, is the largest lift station in the District’s system. All sewage is conveyed to this facility and pumped to the SOCWA Coastal Treatment Plant. Project elements include the following: constructing a new sewer lift station including all piping; demolishing the existing lift station; connecting the new Lift Station 2 to the existing sewer, including piping and manholes; constructing an equipment building; installing new electrical, power, and control interface with the District’s SCADA system; installing a SCADA control panel, PLC, and human machine interface (HMI); installing an antenna for radio communications with the SCADA panel; and constructing a retaining wall, drainage channel, and connection to existing storm drain pipeline.

Shoring Systems
The geology consists of hard bedrock and permeable sand, creating highly variable site conditions. In addition, the site is located in close proximity to the beach where groundwater is very shallow. Various forms of shoring are being considered, including Secant Pile walls, Sheet Pile, Beam and Plate, and lagging.
Each area of the excavation is being evaluated, and the best method will be selected based on the type of rock or soils that are encountered. A combination of the methods described above will be employed.

Dewatering Methods
Dewatering methods will be selected based on the subsurface features encountered. In addition, the shoring system(s) will dictate the dewatering methods. Dewatering will include several well points outside the perimeter of the excavation in addition to dewatering from within the confines of the excavation via a sump pump system.
The dewatering system will need to run 24/7.  Since the project is located in an environmentally sensitive area, precautions will be made to treat the extracted water prior to discharge into the storm drain system.