Hurricane Katrina ripped the parapet cap off of one side of an 18-story high-rise Class A office building in Metairie, Louisiana, allowing heavy water intrusion down two faces of the building. Power and mechanical failures resulted in the loss of control of indoor environments, which contributed to the spread of biological contamination and the support of fungal colonization and amplification on affected building materials, building contents, interior spaces, mechanical areas, and structural areas.
Within days after the Hurricane, we conducted space-by-space inspections of tenant suites to identify building materials with elevated moisture content and visible mold. It was discovered that one side of the building was wet and contained significant mold growth, while the other side had remained dry and mold free. We broke the building into two zones to isolate the mold contaminated areas, and maintained the contaminated area at a negative air pressure relative to the clean areas in order to prevent the escape of mold spores. Drying equipment was installed, and HVAC equipment was temporarily modified to dehumidify and condition the dry side of the building. This permitted half of the building to be occupied while remediation proceeded in the affected areas. A sampling and surveillance program was implemented to monitor existing conditions, ensure that acceptable indoor air quality was being maintained, and identify fungal colonization and amplification in contaminated areas. During the project we acted as the Owner’s Representative monitoring the remediation and restoration work, and assisting with the owner’s insurance claim.
At completion of remediation work, we performed clearance testing and released office space for re-occupancy on a floor by floor basis. It is interesting to note that airborne spore levels in remediated areas were far cleaner than outdoor ambient conditions in the post-Katrina New Orleans area.