By Diana Lee, Intersections South LA and Pierce Larsen, Annenberg TV News 

South L.A. residents protested against oil company Freeport McMoRan yesterday by marching through Jefferson Boulevard in their fight against disruptive – and potentially hazardous – drilling operations.

This isn’t the first time Freeport has clashed with residents over their concerns about noxious fumes, truck traffic and health hazards. The company, which runs 34 wells in Jefferson Park near the University of Southern California, faced numerous criticisms from residents when it tried to get a permit to expand its site last November.

The oil and gas group announced yesterday that it would be conducting a “routine cleanout,” according to issue advocacy group RALLY. In response, locals traveled to the drill site on Jefferson while holding signs and singing, “Stand together!” Others followed with: “…against neighborhood drilling.”

But the trucks didn’t come rolling in like the residents expected. In a gathering before the march, community organizer Niki Wong told residents that 15 minutes before the scheduled 7 a.m. visit, she got a notification that Freeport had cancelled.

“There is no maintenance work planned for today,” Freeport told Intersections in a statement.

Wong, who represents the Redeemer Community Partnership, decided to continue with the protest.

She said what the company calls a “routine cleanout” essentially refers to acid drop, in which they bring tens of thousands of gallons of hydrochloric acid and corrosive liquids to put into the area’s wells.

“The process for why they do it and how they do it is not very clear,” she said.

Wong believes the company has not been transparent about its practice to the residents, who only began getting work notices since 2012 through the South Coast Air Quality Management District, the agency in charge of air pollution control for Los Angeles. She wondered if the company got tipped off about their planned march and decided to call off their visit.

The company said it provided notice to the management district to conduct “routine and conventional well maintenance work,” comparing the task to what might be performed on water supply wells in Los Angeles, as well as all over the world.

Freeport said in a statement: “The work is designed to remove calcium deposits from building up inside the well bore. Rumors and assertions that hydraulic fracturing or well stimulation work are being planned are not accurate.” The notice given to the SCAQMD shows there was no plan for hydraulic fracturing, a process of using high pressure to pump liquid down a well and fracture the rock.

The agency received 29 order complaints about the oil company’s practices in 2014, according to spokesman Sam Atwood. After investigating these claims, SCAQMD issued two violations to Freeport over air pollution and odor.

Atwood said he thinks the oil company was told about the protest, but is unsure if that was the reason it called off their plan for maintenance acidizing.

Whether the trucks carrying toxic chemicals are responsible for health problems is still unproven.

But Kathryn Wiley, co-founder of Church of the Redeemer, said her sons now experience asthma and bloody noses. She worries that air pollution caused by oil sites is the culprit.

“I physically have seen these trucks come in and out around 6:30 or 7 in the morning,” she said. “They have people standing out, rushing them in before anybody could see them.”

Like Intersections on Facebook, follow us on Twitter and sign up for the Newsletter to stay in the loop on news and views from South L.A. Follow the author on Twitter at @atdianalee.

Also see this story at Annenberg TV News.