A Los Angeles County official said this week that haul trucks used for the Devil’s Gate Dam sediment removal project would restart on Monday and would be able to use two wheel washers to address dust issues that shut down the diesel vehicles for about three weeks.
L.A. County Public Works Assistant Deputy Director Steve Burger provided the update at a Tuesday night community meeting called by a citizens group to discuss the monitoring of tailpipe emissions from trucks used in the project, also known as the Big Dig. The session was held at the La Cañada Unified School District board room, the site of a similar meeting Tuesday morning.
“We got all the moving pieces in place, so the plan is for Monday,” Burger said of the trucks, adding that he and other county officials would be at the site to make sure everything proceeds correctly.
The two wheel washers should correct the dust problem, with trucks stopping to have their tires cleaned before leaving the worksite, Burger said. Installation of a concrete path where a gravel path had existed also is expected to help.
He added that testing to begin the process of implementing tailpipe emission standards should start about three to four weeks after the trucks resume work or “essentially as soon as we can get it in place.”
At both meetings, LCF 4 Healthy Air co-founder Elizabeth Krider spoke about the proposed emissions testing. The organization comprises local residents who seek to reduce safety and health hazards to the community.
Krider said the tests were to measure how the diesel truck engines, manufactured no later than 2010, performed with regard to oxides of nitrogen, and the testing would involve the University of Riverside College of Engineering Center for Environmental Research and Technology, the California Air Resources Board and the county Department of Public Works.
Forty-five to 50 trucks will be selected for tailpipe emission devices from among approximately 85 trucks working daily, using a cross-section of different truck years, engine types and makers, Krider said. In the interest of collecting reliable data, participating drivers whose trucks violate emissions standards will not get a ticket from CARB, and testing is expected to take 15-20 minutes per truck.
Krider said monitoring would start in October with a sensor used to track pollution as the truck drives. In April 2020, after measuring devices are available, there will be an inspection of the tailpipe as the truck drives.
The UC Riverside center will place the devices on the trucks and report the findings to the county Department of Public Works and the air resources board, and they will work together to understand the findings, Krider said.
“This represents a pretty significant departure that there’s a public component to it,” Krider said.
Todd Sax, chief of CARB’s enforcement division, said the project was one of a kind.
“The project that is being done here is groundbreaking not just because it requires 2010 initiatives but also because it requires visible wheel checks and visible emissions checks and now the emissions testing,” Sax said. “What we’re going to try to do is take the lessons here and see how it’s best utilized. Especially in the context of a world with [an upcoming] heavy-duty smog check program on trucks. We’re going to take what we can here and see where we can apply it.”
LCUSD Superintendent Wendy Sinnette described how the district was using real-time monitoring of various particulate matter at La Cañada High School, which is near the Big Dig site.
She said there are five instruments of real-time air quality monitoring in each of five locations at the high school: the northeast corner of the south gym, the quad area, the track inside a portable classroom, a gardeners’ shack located off a field and opposite the tennis courts at Oak Grove Drive, and the southwest corner of the south gym.
Sinnette said the particulate matter monitoring, in which data is sent to a cloud for archiving through Yorke Engineering, is updated every five minutes. The archiving includes the particulate matter and the air quality index for different averaging periods.
She said there are notifications in a “four-stage escalation” beginning with a healthful level — green — to yellow, orange and the worst level, red.
With a red notice, an alarm notification would be sent to county and district officials and a school administrator would go to the alarm site to make sure the information was correct. A principal would make sure classroom doors are closed, physical education and other outdoor activities would be moved indoors, and families would be notified via text message as necessary, Sinnette said.
About 40 people attended the morning session and more than 50 attended the night session.
District parent Christina Conwell said after the morning meeting she was pleased that everyone involved continues to try to find solutions.
“It’s not like you come to this meeting and ‘this is the way it is and it can’t be changed,’” said Conwell, parent of an 8th-grader at LCHS 7/8 and a La Cañada Elementary School student. She said her two children are paying attention to the issue.
“It’s something that’s on their radar every day because we drive down to the high school twice a day and we interface with the trucks, we interface with the street sweepers, and we interface with the traffic controls. We turn the air filter on high when we get close to school. It’s something they’re very much aware of,” she said.
Officials have said the project, whose first phase began in late November, is expected to include up to 425 daily round trips by as many as 95 diesel trucks through the intersection of Berkshire Place and Oak Grove and onto the 210 Freeway.
The project, which county supervisors approved in November 2017, is aimed at removing 1.7 million cubic yards of sediment behind the dam at Hahamongna Watershed Park to increase flood protection and restore habitat within the Arroyo Seco Watershed. Work to clear out trees and vegetation began in late November; sediment removal began on May 21.
During the break in hauling, Burger said there had been 71 hauling days and 24,818 truck trips removing approximately 360,000 cubic yards of material to date.
In early August, county officials said it would take up to three weeks to install a wheel washer and start a pilot tarping program to cut down on dust at the project.
Since the hauling project began, there have been four violations related to dust, a spokesman with the South Coast Air Quality Management District said on Tuesday.
