Smaller Pumps Installed in Temescal Rainwater Holding Tank

Workers are on Temescal Canyon to install the correct-sized pump in the underwater tank.

The construction, to ensure that the stormwater runoff in Temescal Canyon was cleaned – and reused – rather than rushing into the ocean, started in 2012.

Now, 10 years later issues are being resolved to use that water to irrigate the park that borders on either side of Temescal Canyon Road.

Geosyntec, a consulting and engineering firm, had been hired by the City to ensure that the system, which has not been operational, will work once larger pumps are replaced with smaller ones.

The original project included capturing the initial phases of stormwater runoff, which is the dirtiest, and putting it in the underground holding tank.

The tank is located below the playground. Once the current repairs are complete, the project will reuse all water captured, either on-site or at Hyperion recycling plant.

Any remaining water would be piped to the bottom of Temescal Canyon and be pumped to the Coastal Interceptor Relief Sewer, which goes to the Hyperion Wastewater Treatment Plant in El Segundo.

The system has not been operational because the pumps located in the holding tanks were pumping too much water for the sewer pipes.

No one suspected that the 16-inches diameter discharge pipe at the base of the Canyon, would feed into to a 9-inch diameter sewer pipe, a few miles south of Temescal Canyon Road, near the Lifeguard Headquarters.

The size of the pumps in the holding tanks meant that too much water was being discharged, and the 9-inch pipe couldn’t handle it.

Once the problem is resolved, stormwater can be treated onsite (behind the restroom buildings) and be reused in irrigation.

The initial project, which started in 2012, was estimated to cost $14.2 million, (raised to $17.7 million) and was funded under Prop O and the Clean Water Act. Project completion was slated for 2013.

The system was to include a diversion structure (16 ft. by 12 ft. and 24 ft. deep), a hydrodynamic separator and a 1.25-million-gallon cement-reinforced holding tank buried beneath the playground.

From that tank, runoff would be cleaned to be used for irrigation and water the tank couldn’t hold would be pumped to the Hyperion.

The project was shut down in 2012, as this editor reported in a story, “An investigation was under way Friday into the death of one of two men who became trapped in a trench in the Pacific Palisades area while working on a city storm water project, authorities said.

“The victim, later identified by the county coroner’s office as 50-year-old Gilbert Vargas, was found buried up to his chest, unconscious and not breathing, when firefighters arrived in the 200 block of North Temescal Canyon Road near Pacific Coast Highway at 1:34 p.m. Thursday, said Erik Scott of the Los Angeles Fire Department.

“The other worker, who had been buried up to hip-level in the trench, was freed around 3 p.m. and taken by ground ambulance to the parking lot of Will Rogers State Beach, where a fire department helicopter flew him to a hospital in serious but stable condition, Scott said.”

Construction resumed and the first part of the project was completed in 2013.

The second phase of the construction started in August 2016, and included constructing the stormwater treatment building, a submersible pump (inside the existing underground tank), 2,500 feet of treated stormwater line and 2,800 feet of new irrigation pipline. at a projected cost. The cost was estimated at $3.1 million.

Currently, Geosyntec is onsite at Temescal working to replace the new pumps. Once that is done, the system should finally be operational – just in time for the rainy season.


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One Response to Smaller Pumps Installed in Temescal Rainwater Holding Tank

  1. K.C. Soll says:


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