Ascon resumes cleanup of Huntington Beach landfill site

Ascon has again started work on remediation of its former landfill site in southeast Huntington Beach.

Excavation and grading work began Tuesday in areas of lower odor potential in the southern area of the 38-acre toxic site, located at the corner of Magnolia Street and Hamilton Avenue.

According to Ascon, about 150,000 cubic yards of on-site material remain to be excavated and graded. At that point, an environmental cap will be installed, comprised of clean fill and low permeability layers.

Remediation is expected to take 27 months total to finish, with excavation and grading lasting 17 months before adding the cap and permanent fencing.

“Once all this work is done and this is constructed, the Ascon team has long-term monitoring obligations,” Department of Toxic Substances Control senior engineer Ben Stanphill told residents at a community meeting last month. “They are not going anywhere. They’re going to need to monitor soil vapor and groundwater and maintain this cap that they’re constructing into perpetuity.”

The Ascon site was an active landfill from 1938 to 1984, receiving first oil production waste, then construction debris and industrial waste.

Remediation work was paused in 2019 by the Department of Toxic Substances Control, until enhanced safeguards could be implemented. DTSC is the lead regulatory agency for the Ascon project.

At the time, a teacher at nearby Edison High reported odors.

There has been work done since then. Removal of toxic waste from “Pit F,” an especially toxic part of the landfill, was completed in 2021.

Ascon was also required to build a 16-foot wall around the site as a requirement to restart, Stanphill said, while completing an assessment to better understand where the odorous soil was and what was causing the odors.

Ascon plans to resume remediation work at a slower pace, using odor suppressants. Ascon was trying to move 1,600 cubic yards per day in 2019 when work was paused, Stanphill said at the meeting.

“Going forward, we’re not going to have that conversation anymore,” he said. “They can only go as fast as they can manage the odors. If that’s 500 yards a day, OK. If that’s 2 yards a day, that’s what it is.”

DTSC project manager Nick Ta said at the meeting that he understood the cleanup had to take into account both residents who lived close to the property and the “vulnerable populations” nearby, including students and children at the park.

In September, the City Council unanimously approved the Magnolia Tank Farm project at an undeveloped site adjacent to where the former landfill is located.

“Engineering-wise, we’re confident that the remedy that we’re going to put in place is protective of the community,” Ta said.

An Ascon information table was set to be in Edison Park this week to answer community questions. An air-monitoring technician, wearing an Ascon-labeled orange safety vest, will be monitoring outside the site during active excavation work. Off-site air monitoring trailers have also been placed east of the site, in Edison Park and near Eader Elementary and Edison High.

Residents who want to report something or have a question can call the Ascon information line at (714) 388-1825, or email [email protected].