Parents share devil in details of county’s plan to remove Hahamongna Park sediment

Elizabeth Krider, a La Cañada Unified parent and area science teacher, explains the health risk of the county’s Devil’s Gate Dam sediment removal might be worse than anticipated in a Dec. 5 informational meeting at La Cañada High School.
(Photo by Sara Cardine)

In an informational meeting held last week, La Cañada parents learned about the county’s plan to remove 2 million tons of sediment from Devil’s Gate Dam via 425 daily truck trips in and out of Hahamongna Watershed Park starting in April.

They heard from a panel of health, science and environmental experts — most of them La Cañada Unified School District parents — who detailed the health risks of idling diesel trucks hauling sediment near schools and emitting potentially carcinogenic particulate matter.

Although the project has been in the works for nearly a decade, and initial preparations are already underway, many who attended Wednesday’s forum were hearing the details for the first time.

And what they heard scared them.


“Nothing gave us comfort whatsoever,” said Hovik Abnoosi, whose two sons attend Palm Crest Elementary School.

“If anything, it gives us more concerns,” added wife Adrineh Ghazarian, a La Cañada Flintridge Educational Foundation board member.

Hundreds crowded into La Cañada High School’s auditorium to hear about the project and an effort being led by parents and LCUSD officials to reduce the daily hazards of the four-year dig through monitoring and assessment.

Parent Heather Wipfli, assistant professor of preventative medicine at USC’s Keck School of Medicine, explained how particulate matter less than .1 micron in diameter can lodge in respiratory systems, increasing chances of lung cancer, heart attack and asthma.


She said USC’s Environmental Health Centers can and will assist La Cañada groups who collect data on diesel fuel emissions.

Elizabeth Krider, an LCUSD parent who teaches science research classes at Flintridge Sacred Heart Academy, explained how real-world conditions like trucks’ braking, tire wear and faulty nitrogen oxide (NOx) filters can increase emissions beyond the county’s estimates.

So where the county concluded the health risk of the Devil’s Gate clean-out was 1.9 in 1 million (meaning one person in 1 million exposed continuously to the output level would likely develop cancer), Krider said factoring in real-world emissions would yield a risk closer to 14 to 23 in 1 million.

“The final environmental impact report didn’t include these subtleties, but for us they’re essential,” she said.

In a Q&A session, audience members queried panelists including Krider, Wipfli, LCUSD Supt. Wendy Sinnette and Dan Lafferty, assistant deputy director of the county Public Works’ Environmental Programs Division.

Lafferty explained why hauling could not be restricted to nighttime or summertime schedules and why electric trucks aren’t strong enough to handle loads. Krider asked whether the county might more stringently monitor emissions and ensure filtration system functionality.

“It certainly makes sense to me that we would come up with some sort of inspection program on site to be sure, at least at a minimum, the emissions control systems that are on the vehicles are doing what they’re supposed to be,” Lafferty replied.

Afterward, parents turned in volunteer cards indicating their willingness to write letters, make phone calls and attend future meetings. Palm Crest mom Karen Thurston took extra cards to give friends who couldn’t attend Wednesday.


“I get that the project is necessary. I just want to make sure we’re going about it in the most responsible way we can,” she said.

In an interview Tuesday, Sinnette said, “It’s incumbent upon the district to do an independent analysis. We’ve engaged a legal team and we’ve hired an environmental consultant to do an independent analysis of both health risk assessments.

What we’d really like to see is some type of regulation that was on or near campus that had regulatory power so that if the regulatory agency determined the particulates or the environmental quality was not safe that the project could be slowed or shut down until it was deemed safe.”

Adena Asatoorian, mom to fifth- and eighth-grade daughters, said she was horrified by the massive truck schedule. Her family moved to La Cañada from Granada Hills 10 months ago, in part, to escape the lingering effects of the Aliso Canyon gas leak.

During that disaster, Asatoorian saw how health ailments like the ones her family experienced — chest pains, blurred vision, vomiting — were ignored by officials. She said she plans to volunteer to make sure the Devil’s Gate project has a different outcome.

“We picked here because we thought it was in the woods and it was going to be healthy and clean,” she said. “This is just a super shock to me. It’s like a nightmare, honestly.”

Twitter: @SaraCardine