As if the task of transforming one of the city's most notorious housing projects into a new "urban village" wasn't daunting enough, Los Angeles has run into another hurdle in the redevelopment of Jordan Downs: concerns over contaminated land.

City officials earlier this year approved a plan to spend up to $1 billion to turn the often dangerous Watts housing development of 700 derelict units into a mixed-income community of up to 1,800 stylish new apartments.

But the plan hinges on building the first phase of the new community on 21 acres of former industrial land that is laced with lead, arsenic, oil and cancer-causing industrial chemicals from its past use as a steel factory.

The Housing Authority of the city of Los Angeles has pledged to remove the contaminated soil to make the site safe. Officials estimate they will spend up to $8 million to haul away thousands of truckloads of contaminated soil and replace it with clean material.

"This has been an industrial site for decades, and so I would think people would be happy that we are stepping into this void to actually deliver this sort of cleanup," said Doug Guthrie, the head of the city's housing authority. The agency is seeking approval to begin work as early as the spring.

But activists, residents and environmental groups say the cleanup plan falls short of protecting the health of future residents, particularly children. Some critics are demanding a wider investigation of contaminants, including in soil in parts of Jordan Downs where people have been living for generations, saying they fear pollution has spread or remained there, undetected, for decades.

"We're going to keep insisting they do more testing to make sure it's safe to live there," Lorena Garcia, 42, said in Spanish. She lives in an apartment in Jordan Downs with her husband and six children. "We're the ones who are going to be harmed, especially those of us with young children," she said.

Residents and activists have seized on memos between the state and the housing authority over cleanup standards that they say show the plans are not thorough.

An assessment of the vacant site in 2011 found lead, arsenic and industrial compounds known as polychlorinated biphenyls at levels that would pose an "unacceptable" health risk to future residents, particularly children. The analysis by a city-hired consultant also found unhealthy levels of naphthalene, an ingredient in mothballs, in vapors in the soil.

Most concerning to both regulators and activists is the soil's lead content. Children who play in dirt contaminated with the poisonous metal can ingest the dust. Over time it accumulates in their bodies and even at low levels can cause permanent health problems and learning deficiencies.

A toxicologist hired by the housing authority initially called for a cleanup plan that would leave lead in the soil at a level more than six times higher than the state standard of 80 parts per million for residential areas.

The state Department of Toxic Substances Control wrote in a 2011 memo to the consultant that the higher level "may not be protective of a child resident" and called for meeting the 80 ppm standard.

But the remediation plan the city drafted earlier this year sets the goal at 315 ppm, nearly four times the state limit.

Asked about the discrepancy, state toxics department officials said they will refuse to sign off on the cleanup unless the 80 ppm average is met. Housing authority officials say they will do whatever the state requires.

Those assurances are not enough, said David Pettit, an attorney for the Natural Resources Defense Council. The environmental group is one of several who say the cleanup plan may not be enough for a site that will house families with young children.

"I'm worried about babies rolling around in lead and arsenic," Pettit said.

Some residents say they now fear dangerous metals are not confined to the 21-acre site, which was a truck storage and repair facility after the steel mill closed and is now walled off from the community. The city purchased the site in 2008 for $31 million.

Soil contamination has been a problem in the surrounding area. People in the same zip code as Jordan Downs live with some of the highest pollution exposure in the state, according to a recent analysis by California environmental agencies, and also are in the top 10% of areas in California with the most contaminated land.

Students at neighboring David Starr Jordan High School were evacuated in 2002 after a Navy shell from an adjacent metal recycling facility exploded, launching a chunk of metal onto the campus. Two years later 1,250 tons of soil had to be removed from the school's athletic field because it showed high levels of metals and industrial chemicals.

A nearby property is on a U.S. Environmental Protection Agency list of potential lead-smelter sites that were unknown to state and federal regulators until identified in a 2001 study.

At the request of community groups, a mobile health center was dispatched to Jordan Downs last month to test children for lead. All six of those tested during the first two visits had elevated levels of lead in their blood, said Shom Dasgupta, director of social medicine at St. John's Well Child and Family Center. Their readings, about 3.3 micrograms per deciliter, were above average but did not exceed the level of 5 micrograms per deciliter that health experts consider a cause for concern.

Even so, the elevated levels could be a sign that children are at risk. "To me that means exposure to lead in this area is widespread enough that somebody should be doing more aggressive screening for children," Dasgupta said.

Guthrie, of the housing authority, said his agency decided to forgo soil testing near existing homes because an initial survey turned up no history of industrial use there. Environmental experts the agency hired to drill into the soil of the industrial site saw no reason to test outside its boundaries because metal contaminants do not migrate, he said.

That did not comfort Jordan Downs resident Rafael Zavaleta, 20, who lives within a few hundred feet of the cleanup site and said his family was told they will be among the first relocated to the new apartments because their home would be one of the first knocked down. As a boy, he and his friends would sometimes sneak onto the vacant lot to explore the abandoned factory.

"They would say: You know, the dirt's been contaminated and you might get cancer, and we took it as a joke," he said. Only recently did his family learn of the hazards and become concerned.

"I've already lived here 14 years, so I can't go back in time and say I want my health back," he said. "But a lot of people are growing up here, playing in the grass and playing in the park. We need to know if it is clean, if it is healthy, and to make sure the contamination didn't spread."

tony.barboza@latimes.com

jessica.garrison@latimes.com