In January 2001, a semi–tractor was intentionally driven into the South Portico of the historical State Capitol Building in Sacramento. The ensuing fire and smoke and water used to control the fire caused $16.5 million in damage to the southern part of the capitol building. NES was called to assess whether the building was contaminated by the burning fuel and combustion of interior materials and mold growth from the large amount of standing fire–suppression water used to extinguish the flames. NES identified several carcinogenic polynuclear aromatic compounds at levels of concern were found in Senate Committee rooms and nearby areas of the capitol building.
These aromatic compounds are commonly produced from incomplete combustion of hydrocarbons, likely from the burning of the fuel inside the structure. In some areas of the capitol, where water accumulation occurred, toxigenic species of mold were also found at amplified levels. NES provided remediation guidelines and affected areas were decontaminated by a qualified contractor. Subsequent testing performed by NES cleared the affected areas, allowing the structural restoration work to proceed. Most areas of the first floor housing the Senate Committee rooms were reopened by early summer of 2001 and remaining restoration work on the damaged exterior granite was completed in early 2002.