In 1985 an Initial Assessment Study (IAS) was performed for Naval Weapons Station Seal Beach, Detachment Fallbrook, and Detachment Norco (at that time known as the Corona Annex). No sites were recommended for further investigation at Norco. However, because of concerns from the California Department of Toxic Substances Control regarding some language in the IAS, the Navy agreed that additional study in the form of a Preliminary Assessment (PA) is warranted. The PA was initiated in 2015 and is currently underway.
Public Documents can be found on the Naval Facilities Engineering Command's Norco Administrative Record File.