(top) Santa Monica Councilmember Kevin McKeown holds a plunger during the Colorado Ocean Relief Sewer Project's dedication ceremony at the former RAND site directly west of City Hall on March 26, 2009. (center) Councilmember McKeown cuts the ribbon during the Colorado Ocean Relief Sewer Project's dedication ceremony on Thursday. Alongside of Councilmember McKeown are (left to right) Lee Swain, Director of Public Works; Jennifer Phillips, Assistant City Manager;Laurel Rosen, President/CEO of Santa Monica Chamber of Commerceand Don Smith, FEMA public assistance officer. (above) Councilmember McKeown (holding the plunger) and other civic leaders look into the Colorado Ocean Relief Sewer. This $11 million project was designed and completed by city staff, Black & Veatch, Steve Bubalo Construction Co. and Tetra Tech, Inc. It was funded by wastewater funds and a grant from the Federal Emergency Management Agency.
Purpose: Over two-thirds of the city’s sewage passes through the sewer main at Colorado and Ocean, making it a critical section of the city’s wastewater management. The original 1950’s era sewer main was damaged in the 1994 Northridge earthquake, and the city was unable to repair it due to the constant high volume and location under the 10 Freeway. The Colorado Ocean Relief Sewer Project increases the capacity of the sewer system to accommodate current and anticipated future flows, and provides an additional redundant line for maintenance and emergencies
Construction: Major components of the Colorado Ocean Relief Sewer include large junction structures under Colorado Avenue, additional structures at each end of the 108” diameter tunnel that runs under the 10 Freeway and Holiday Inn property (This tunnel contains two 42” and one 18” high density polyethylene (HDPE) inverted siphon carrier pipes), and all connecting sewer lines. An inverted siphon design works like the u-shaped drain trap under a typical bathroom sink, many times enlarged. Gravity maintains the flow of wastewater downhill under the Freeway, which pushes the sewage uphill on the other side. This does not require a pumping station, lowering energy consumption and reducing construction and maintenance costs.
Timeline: Staff began planning for the project in 2004. Initially, ten different alignments were considered. The selected alignment was chosen because it provides the greatest benefit to the city with lower construction costs and public impacts, as well as lower operational costs. On February 28, 2006, Council approved a contract with Black and Veatch to design the project. Later that year, on December 5, Council authorized the acquisition of a sewer easement below the Holiday Inn property. Construction contracts were awarded on October 23, 2007 after a competitive bid process. Major construction took place from December 2007 to December 2008. Substantial completion was attained when the new lines were in use in December 2008, after which the original lines were repaired and structurally lined for use as a redundant system.
Funding: Total budgeted cost of the project, including design, construction, property acquisition and project management were under $12 million. The Federal Emergency Management Agency provided funds for numerous upgrade projects throughout the City as a result of the 1994 Northridge Earthquake. In 2006 those projects were 95% complete with balances remaining. City staff received authorization from FEMA to utilize a portion of the remaining balance for the Colorado/Ocean Avenue Relief Sewer Project.
