The naval station is a Superfund site — a label given to hazardous waste sites that pose a risk to human health or the environment.
In 1944, a load of munitions exploded at the station as the weapons were being loaded onto a cargo vessel. The Navy has been working to clean up the land since 1983, when it identified around 1,200 acres that had been contaminated. The soil at the site contains chromium, a radioactive isotope, and the groundwater contains industrial chemicals like trichloroethene and tetrachloroethylene.
The Environmental Protection Agency says the land doesn't present a risk to human health, but levels of contamination in the groundwater still aren't considered safe. Last year, Concord's former mayor, Edi Birsan, said the land was "not suitable for public habitation."
The city plans to work with the Navy to make the site suitable for human occupants and get it off the Superfund list.