A stream of cement trucks regularly rumbles by Gayle Hart’s townhouse on Gilman Avenue in Hunters Point, headed to and from construction sites throughout San Francisco.

“Look how the dirt is just flying up here,” the San Francisco Muni driver said from her dust-covered balcony, which overlooks one of the routes Bauman Landscape and Construction Inc. trucks take to deliver 40,000 tons of concrete annually.

“I don’t even want to open the window, because the dust flies right in,” said Hart’s neighbor, Violet Moyer, who runs indoor air cleaners around the clock, hoping to help her three children breathe easier. “I used to wake up in the morning and I didn’t feel congested -- and now I do.’’

Hart and Moyer recently joined other residents in speaking to NBC Bay Area’s Investigative Unit about their health concerns from the dust that coats cars, obscures windows and collects in the street. They blame activities on a site across the street from their homes, Bauman’s 1.5-acre Redi-Mix plant.

They say the city has not provided much relief from the dust that has gotten worse since the plant opened across from their homes a year and a half ago – calling into question whether the city is living up to its vaunted environmental justice ideals.

“This is not a dumping ground,” said Kamillah Ealom, an environmental activist with the local Greenaction group and a resident of the nearby Alice Griffith public housing development. “So right here, in my own backyard, I’m fighting for environmental justice – and I’m from San Francisco, the leader in environmental justice.”

“The residents here are suffering, without question,’’ said Ray Tompkins, a retired chemistry teacher who serves on the African American Community Health Equity Council in the Bayview.

Tompkins visited the site recently with a hand-held pollution detection device. It analyzes concentrations of microscopic PM 2.5 dust particles – which measure about 1/30 of the thickness of a human hair. Studies show PM 2.5 particles – a recognized byproduct of concrete operations --  are linked to respiratory problems ranging from asthma to lung cancer.

“Anything over 3,000 is poor,” Tompkins said. His measurements in the area, he says, regularly approach 6,000 – twice the level considered a “poor” air quality level based on the concentration of PM 2.5 particles. “This is on a consistent basis,” he said of the 6,000 concentration level. “I’ve measured up to 28,000 with trucks running by.”

Tompkins says he found elevated PM 2.5 levels near Bret Harte Elementary School, where children play outside during recess, as well as out front of the nearby Alice Griffith public housing development.

Plant-owner Mike Bauman told us his family-run operation is not to blame, saying other businesses on that site generate dust.

Bauman said he has been running a Redi-Mix operation on the Gilman Avenue for about a year and half. The operation involves crushing up and recycling enough old concrete to create 40,000 tons of fresh concrete annually, he said.

“We’re really conscious of not causing problems out there,” Bauman said, stressing that his crews spray down their trucks, wheels and the street area to limit dust.

While Bauman acknowledged his plant was indeed cited by the Bay Area Air Quality Mangaement District for not having a local permit, he said there was no fine for air quality violations and he has a permit issued by the state Air Resources Board. He said the citation he received from local authorities was the product of a  jurisdictional squabble between licensing authorities.

Bay Area Air Quality Management officials did not respond to requests for comment about the citation the agency issued against the plant. The inspector handling the violation notice told residents recently that the process to resolve the permit violation matter could be a lengthy one.

Frustrated residents had counted on Board of Supervisors President Shamann Walton, who represents the neighborhood, to help. His office provided a statement saying it was Walton who forwarded the residents’ complaints to the air quality management district in the first place, adding:  “Our office is 100% in alignment with our city’s environmental justice practices.’’

But Hart says that hasn’t spelled any relief. In her mind, the problem has only gotten worse.  She and other neighbors said they noticed even more dust when more trucks were rerouted through their neighborhood after Hunters Point Expressway was closed last year to provide temporary parking for people living in RVs.

“I can't breathe around here,” Hart said. “I don't even want to go outside at all because of the dirt. And when it's windy -- it's like a sandstorm -- you could just see it blowing around. This is not right at all.”