Mayor Mark Farrell wants to set the record straight: He absolutely would recommend the San Francisco Shipyard development to friends or relatives looking to buy a condominium, regardless of the escalating scandal over the botched cleanup of the Superfund site.

On Wednesday, the mayor, who was recently quoted saying he would be loath to suggest that a friend or relative buy a unit there, joined a considerable entourage of city staffers for a tour of Parcel A at the former Hunters Point Naval Shipyard. The area, on a sunny, windblown hilltop overlooking vast expanses of asphalt and old Navy buildings — most of them mothballed more than 40 years ago — is being built up and is the only part of the San Francisco Shipyard development that already has residents.

The tour was a chance for city officials to put a positive spin on an environmental problem that threatens to delay significantly, and possibly permanently alter, the Bay Area’s biggest redevelopment project. The reimagining of the former Naval facility is to include more than 12,000 housing units, schools, research and development facilities, office buildings, parkland, and artist studios in a corner of the city that has historically been one of the city’s poorest and most neglected.

The tour came as the Environmental Protection Agency and the Navy have committed to retesting much of the soil at the shipyard site that was supposed to have been evaluated and cleaned up by Tetra Tech, the environmental engineering company responsible for ridding the site of nuclear residue and other toxic materials. Two Tetra Tech employees have pleaded guilty to cheating when testing soil at the site and have been sentenced to eight months each in prison.

Farrell said that while he has been disappointed with how slowly the Navy and the EPA have responded to the problems, he didn’t mean to imply in his previous comments that home buyers should avoid the site.

“The development here in Parcel A, these homes, are amazing opportunities for San Francisco residents. Of course, I would absolutely recommend people come out here,” he said.

Farrell reiterated his demand that Parcel A be tested for radioactive materials. Tetra Tech worked on only one building on Parcel A, Building 322, which was scanned for radioactivity and then removed from the site in 2004. But whistle-blowers have questioned the veracity of that information and say high levels of radioactive materials were found a few feet outside the edge of Parcel A. The soil within the site, which did not house nuclear operations during the Navy’s decades at the shipyard, has never been tested.

“We need to make sure future development is safe and give people the security of knowing that their families are safe,” the mayor said. “San Francisco residents need to be able to feel safe in their homes — plain and simple.”

Supervisor Malia Cohen, who represents the Bayview district and was upset by Farrell’s negative statements about the condition of the shipyard site, said that she was pleased that Farrell “took the time to take a tour.”

“It’s too bad he put his foot in his mouth, but I’m grateful that he is educating himself and recanted his words,” she said. “It’s an important signal to the community.”

The shipyard was home to the Naval Radiological Defense Laboratory from 1946 to 1969, when tests were conducted to determine the effects of radiation on living organisms, and ships contaminated by atomic bomb explosions were dry-docked at Hunters Point. Most operations ceased at the shipyard in 1974, and it was shut down as part of the U.S. Base Realignment and Closure process in 1991.

The city staffers on the tour also got an update on the retesting of the Tetra Tech work. Amy Brownell of the city’s Department of Public Health said the Navy has committed to having a work plan ready by the end of June. There will then be a 60-day community review of the plan before work starts.

As she has in the past, Brownell, who has worked on the cleanup for 25 years, said that Parcel A doesn’t contain any materials with dangerous levels of radioactivity. However, she said the California Department of Toxic Substances Control will scan Parcel A for any indications of hazardous materials.

She also said that she doesn’t think the retesting anywhere at the shipyard site will result in any discoveries of contamination that would pose a risk to the public.

“These stories about contamination are true and fascinating, but a lot of them are old — the contamination has been cleaned up,” she said. “We can say definitively there are no public safety concerns or health concerns out here.”

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com

Twitter: @SFjkdineen