Case Study ― Gentilly Neighborhood in New Orleans


Gentilly house in New Orleans

Description of House and Condition 

Home #2 is an owner-occupied one-story house, roughly 100 years old.  It is a raised home on piers that received at least five feet of flooding. Mold growth was found up to the ceiling of the house.

Mold Removal Treatment

Work was conducted November 15 to November 17, 2005.  Final Biocide spray was applied on December 2.

Pile of debris Gentilly house in New Orleans

Possessions were removed and discarded.

Wallboard studs Gentilly house in New Orleans

All wallboard on walls, insulation, and lathe were removed. Studs, ceiling, bath tile in both baths, and materials backing tile were left in place.

Workers in a Gentilly neighborhood cleaning surfaces with bleach/detergent solution

All surfaces were cleaned with a bleach/detergent solution.

HEPA vacuum Gentilly house in New Orleans

Studs were HEPA vacuumed.

Worker spraying studs with borate solution

Studs were sprayed with a borate solution.

Summary and Conclusions

Health Risks: In this home, live mold spores in the air were greater than 1,000 times normal background levels during demolition. Our sampling showed live mold levels in the millions during the remediation process. We did not sample for a full spectrum of contaminants, but data collected by the EPA did not show significant levels of any of the 200 chemicals that were tested. Numerous EPA samples did reveal elevated bacterial levels.

Effectiveness: In this home that experienced at least five feet of standing water for at least two weeks, we have successfully reduced the mold to non-detectable levels. The drying process and cleaning of all surfaces in a home, including upper walls and ceilings, are critical to the success of the clean-up. 

Cost Information: The cost of this decontamination process, after all possessions and furnishing have been removed, is between $3.40 to $4.10 per square foot of floor area or about $4,400 for an average 1,200 square foot home.  Homes flooded 18" deep will cost between $32,000 and $47,000 to complete repairs after decontamination. Homes flooded 6' deep will cost between $78,000 and $120,000.

Worker Protection: We know that homeowners and workers are being exposed to very high levels of mold, and we are very concerned about respiratory problems and other health effects. We are recommending that homeowners or others entering the home to remove belongings or perform other activities that would not disturb mold use an N-95 mask and limit their exposure to 15-minute increments. We recommend that workers and others spending longer periods in the building wear N- or P-100 masks. These respirators provide a good level of protection, but do not screen out all of the spores that may be present in a home. They are rated by OSHA as having a protection factor of 10, which clearly is not sufficient when the mold levels are in the millions (colony forming units/cubic meter of air). Power air-purifying respirators (PAPR's) provide the highest level of protection, but at a cost over $500, are less affordable to most homeowners. Workers should also wear goggles, plastic gloves, and disposable coveralls. If protective clothing is not worn, clothes should be washed after each day.

 Worker wearing protective mask Gentilly house in New Orleans  Workers wearing protective masks Gentilly house in New Orleans  Workers wearing protective masks Gentilly house in New Orleans




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