As general contractors, we witness the aftermath of all kinds of severe weather and disasters. While each type of natural disaster presents its own hazards for work crews, perhaps none create more health and safety challenges than eradicating black water. (Black water contamination usually results from standing water from storm flooding – or in the case of one of our recent apartment community clean-ups – a sewage leak.)
Fifty-five units experienced water damage from the public sewer, causing more than $1 million of destruction. The apartment community had a category 3, level 3 black water contamination – which is the most severe, and has the highest potential to cause diseases (like hepatitis A) and to produce mold spores.
The first step was to remove all the waste water from the building. Once the flood waters receded, vacuums were used to pump water from the units. This process took crews four hours and all the contaminated refuge was dumped back into the sewer. When the water was sufficiently eradicated, all affected interior flooring and drywall had to be safely discarded. In this case, the flood saturated the units – everything from the ground up to four feet had to be removed.
After all of the ruined flooring and interior materials were disposed of, the work crew focused on cleaning the air inside the units. This was done using a High Efficiency Particulate Air (HEPA) filter. The filter purified the contaminated air, and then pushed clean air outside. HEPA filters, in particular, are the sole filter recognized by the Center for Disease Control as an effective tool to capture microscopic disease-causing particles and mold spores.
However, the decontamination process did not stop with air purification. Everything had to pass a sanitation test, down to the studs and base flooring. To determine if the apartments were safe, a strip test was performed by an environmental consultant to gauge bacteria levels. When the results proved that the black water damage had been successfully eliminated, reconstruction was allowed to proceed.
We only had only three months to complete repairs and the company worked on all 55 units simultaneously. Currently, we are finishing completing interior construction on the last remaining units and tenants are moving back in.









