Emergency Response In Compton

April 2014, Vol. 69 No. 4
Lightweight pipes were easily handled onsite, even with limited workspace.

When the Sanitation Districts of Los Angeles County (LACSD) were formed in the 1920s, the agency embarked on its first major project – the construction of the backbone trunk sewer of the Joint Outfall System (JOS).

Since then, the Sanitation Districts have completed many challenging projects, providing environmentally sound, cost-effective wastewater and solid waste management services to over five million people in Los Angeles County.

The JOS of the LACSD is a large regional sewerage system consisting of 17 sanitation districts, serving 73 cities and unincorporated areas within Los Angeles County. The economies of scale and efficient operation of the large system have kept sewer rates in the Districts among the lowest of all California and U.S. sewerage agencies.

The Sanitation Districts own, operate and maintain approximately 1,400 miles of sewers that range in size from eight to 144-inches in diameter. They convey approximately 500 million gallons per day of wastewater to 11 wastewater treatment plants. Maintaining this enormous system is an ongoing challenge.

LACSD has been actively repairing sections of Joint Outfall “G” since 2009 with several phases previously rehabbed. The next phase of rehab was scheduled for an October 2013 start-up in Compton. The existing Joint Outfall “G” Unit 9 is a 39-inch clay-tile-lined RCP pipe that was installed in the 1940s along the current Interstate 710 Freeway which connects Pasadena to Long Beach. The freeway was built in the 70s and pipe had to be relocated to allow for this work. In the late 90s, it was observed that the cast-in-place clay tiles were falling due to corrosion in the mortar seal filling the gap between these tiles. Ultimately the tiles in the top half were lost and RCP was exposed to severe hydrogen sulfide corrosion.

The contractor on the most recent section, JO “G” Colich and Sons, LP of Gardena, CA, had to rehab several junction structures. One of them was located in the intersection of Atlantic Street and Greenleaf Road.

“During excavation around the structure, the contractor exposed the 39-inch RCP sewer on the downstream end and found a short section of missing pipe crown. The upstream 39-inch RCP sewer was previously sliplined with Hobas 33-inch FRP and the downstream pipe was scheduled to be rehabilitated in the near future. After CCTV inspection it was determined that approximately 700 feet of sewer downstream of Manhole 847 was deteriorated and needed urgent repair. This emergency repair work was completed as a change order to the existing project,” stated Derek K. Zondervan, P.E., civil engineer, Sewer Design Section for LACSD.