A New Year’s resolution: Keep the creek clean

Reclaimed sewer water might be diverted, officials say


BILL             SPARKES/Acorn Newspapers    MALIBU CREEK--Study examines ways to redirect pollution.

BILL SPARKES/Acorn Newspapers MALIBU CREEK–Study examines ways to redirect pollution.


A New Year’s resolution: Keep the creek clean

The Las Virgenes Municipal Water District and Triunfo Sanitation District have launched a study that will look at ways the two agencies can limit the amount of reclaimed sewer water that is released into Malibu Creek.

The Tapia effluent alternatives study was commissioned through the joint powers authority that oversees both water districts.

In 1997, the Los Angeles Regional Water Quality Control Board restricted the amount of surplus effluent, or treated wastewater, that the Tapia sewer treatment plant near Calabasas could discharge into Malibu Creek. Tapia was prohibited from releasing the treated water from May 1 through Oct. 31 when creek stagnation levels tend to be the highest.

The two districts came under heavy pressure to recycle, divert or store excess wastewater. Las Virgenes experts said they believe the danger of creek pollution has been overblown.

“We know that the (reclaimed) water is very high quality, and we don’t believe it creates a problem during that time,” said John Mundy, general manager of the Las Virgenes district. “It appears to dilute the amount of bacteria that occurs in the creek naturally.”

Others disagree, saying the wastewater contributes to algae growth and pollution.

Other measures

The study initially reviewed 150 projects, but the number was whittled down to four alternatives.

The projects were evaluated according to economic cost and benefit, operational flexibility, environmental impact, public support and sustainability. A price tag was put on the projects and they were ranked from 0 (fatally flawed) to 5 (offering significant benefits and value). The projects were rated 3.0 and above.

The alternative receiving the highest rating was the “ocean outfall” solution, which calls for 40 percent of Tapia’s excess recycled water to bypass sensitive Malibu Creek and flow directly to the ocean. A pump station would be constructed at Tapia, and a pipeline would be built through Malibu Canyon to the Malibu coast. The ocean outfall solution was rated 3.6. The cost of construction was estimated at $55 million, according to the study.

Expansion of the water district’s recycling program ranked next on the viability index at 3.4, and included construction of a reservoir at Donnell Ranch. Currently Tapia recycles 60 percent of its treated wastewater. The water is used to irrigate public and private land, including golf courses and freeway landscaping.

Delicate balance

The recycling program becomes a balancing act between supply and demand.

“For storage to work, sufficient demand must be created to empty the reservoir each year in order to accommodate the next year’s surplus,” the report said.

At $142 million, the cost to build new recycling pipelines will be high.

The lowest-ranked alternative is diversion of surplus water to the Los Angeles River. Although the $65.5-million price tag is less than the cost of recycling, the diversion project faces many obstacles, including potential opposition from environmental groups, the Los Angeles County Department of Public Works and other agencies.

Bird populations would be affected under the diversion plan, and algae growth and other plant and animal life would be impacted all the way to Long Beach, experts said.

Although the ocean outfall solution received the best overall ranking, it also would have serious environmental impacts, the study found.

“I think the thing that the (study) does is provide a lot of good information to our stakeholders, board, and what could be out there in the future,” Mundy said.

Who will pay?

Current customer rates would not be enough to pay for any of the alternatives, Mundy said. State or federal funding would have to be obtained before the Las Virgenes Municipal Water District board of directors could move forward with a solution.

The full report can be reviewed at the Las Virgenes
Municipal Water District headquarters at 4232 Las Virgenes Road in Calabasas.
For a computer CD copy, call (818) 251-2200.



 

 

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