Managing unprecedented asbestos demolition after Katrina  

A water truck wets an ongoing demolition to prevent friable asbestos from becoming airborne. Recovery teams have been able to keep airborne asbestos levels near zero. (Courtesy photo)

Sep. 27, 2007

By Dave Harris and Alice Welch
Louisiana Recovery Field Office

Following Hurricane Katrina, the Federal Emergency Management Agency tasked the U.S. Army Corps of Engineers Louisiana Recovery Field Office to demolish more than 17,000 houses in New Orleans.

The historic nature of the city equates to many old houses having regulated asbestos containing material (RACM).  RACM is one of the acronyms coming out the marshlands of southern Louisiana, and it can be deadly if not handled properly.

Not all asbestos forms are immediately dangerous to human health. Asbestos that is securely encased or enclosed is not an immediate threat.  Asbestos is dangerous if it is "friable." "Friable" means easily crumbled or "powder-like." When asbestos-containing material becomes airborne or friable, it is a dangerous cancer-causing agent.

The majority of these older buildings have transite siding, asbestos slate roofing shingles, asbestos insulation, asbestos floor tiles, asbestos popcorn ceilings or other asbestos-containing material.

When the Corps prepares to tear down a home, very specific and rigid guidelines must be followed.

First, each building is inspected to determine if it will require a RACM-demolition procedure. Only the buildings that have friable asbestos are determined to be RACM demolitions.

The demolition process is steeped in checks and balances to ensure the safety of all the workers and people living in proximity to the demolition site.

The initial actions involve setting up road blocks, flag sentries and air monitors, establishing a safety perimeter around the "hot zone," creating a clean area for decontamination and the staging of the debris trucks.

An average house contains 200-250 cubic yards of debris.  With the numbers of demolition required, it is more efficient to take the whole house in the process, rather than remove and sort out the hazardous portions.

The street around the demolition is sealed off to all but certified personnel.

Demolition begins with the thundering roar of the track hoe reverberating around the neighborhood. The certified worker, in his or her alien-like clothing, sprays water on the house to prevent airborne asbestos particulates.

The heart-wrenching demolition of a home can take from two minutes to all day, depending on the skill of the crew and the size of the home.

During the controlled leveling, collapsed debris is dumped into the lined trucks, tightly sealed by the certified asbestos workers in their protective suits and hauled to an approved dump site for RACM disposals.

At the site, the "burrito wrap" is dumped in one piece into the resting place prepared for it. 

The long-awaited result is a piece of land that is clean, level and ready for a new beginning. The future for the Louisiana homeowner starts now.

Of course, the challenge of safely removing asbestos-containing material from storm-ravaged structures was unforeseen in the early days. But pioneering efforts and a wealth of experience in ensuing years has yielded a wealth of proven, practical measures that reduces the processing risk to nearly zero.