Mitigation Assessment Team Report
Hurricane Katrina in the Gulf Coast
Building Performance Observations, Recommendations, and Technical Guidance
FEMA 549 / July 2006

Chapter 8. Overview of Hurricane Katrina in the New Orleans Area

FEMA was particularly interested in the long-duration impacts of flooding on 
buildings in New Orleans as well as the floodplain management issues surrounding 
the levee breaches. The New Orleans Flood Team conducted ground inspections 
throughout the New Orleans area, including the City of New Orleans and Orleans 
Parish, as well as the nearby communities of Chalmette in St. Bernard Parish and 
Metairie in Jefferson Parish. 

The Flood Team visited a total of 23 residential buildings and critical and 
essential facilities in the New Orleans area from October 4 to 8, 2005 (see 
Figure 8-1). The focus of the site inspections was to assess flood damage to 
residential buildings and critical and essential facilities, and evaluate 
opportunities for flood restoration. The Flood Team’s investigation showed that 
structural damage to buildings was localized to certain areas, and that the most 
significant damage was from long-duration flooding of non-structural building 
components related to saturation of porous building materials with contaminated 
water. 

[Begin Figure]
Figure 8-1. Residential buildings and critical and essential facilities visited 
by the New Orleans Flood Team. (Due to the map scale, some sites are not 
included on this map). This is a map showing Residences, Residence Sampled, 
Critical and Essential Facilities, and Critical Facility Sampled.
1. Residence at Elysian Fields
2. Residence at General Diaz Street
3. Residence at Memphis Street
4. Residence at Savoie Court
5. Residence at Munster boulevard
6. Residence at Cleary Avenue
7. Residence at Octavia Street
8. Fire station at Louisiana Avenue
9. Fire station at Carrollton Avenue
[End Figure]

Section 8.1 discusses flooding in the New Orleans area. Floodplain management 
issues related to levees and floodwalls in the New Orleans area, including the 
history of the New Orleans levee system, and floodplain mapping and building 
construction within the New Orleans levee-protected area, are presented in 
Section 8.2. Section 8.3 contains a general characterization of structural and 
non-structural flood damage. Long-duration flood impacts on buildings, including 
deterioration of building materials and contamination, are discussed in Section 
8.4.

8.1 Flooding in the New Orleans Area 

Flooding in most places within the levee/floodwall protected area in and around 
New Orleans was due to breaches in levees and canals. Pump systems that would 
normally have removed floodwaters were non-operational due to inundation or from 
a loss of primary and backup power. In Metairie, flooding was caused by high 
water from Lake Pontchartrain surcharging the drainage system with pumps off. 
Local officials decided to evacuate pump operators on August 28 before the storm 
hit, according to The Times-Picayune and first-hand accounts given to the New 
Orleans Flood Team. 

As a result of the levee/floodwall breaches, widespread flood damage to 
residential neighborhoods occurred throughout the New Orleans area. The depth of 
flooding within the Greater New Orleans area varied greatly, as did damage to 
structures. West of the 17th Street Canal, areas of Metairie in Jefferson Parish 
had shallow flooding, typically less than 1 foot in depth. East of the 17th 
Street Canal, flood depths in excess of 8 feet were observed in Lakeview on the 
north side of New Orleans near Lake Pontchartrain, the Lower Ninth Ward, and 
Chalmette (see Figure 8-2). Floodwaters remained in most New Orleans 
neighborhoods for approximately 2 to 3 weeks after the levee/floodwall breaches. 
Areas by the Mississippi River and the high ground along Lake Pontchartrain 
between the  7th Street Canal and the Industrial Canal were essentially free of 
flooding. These relatively elevated land areas form parts of the rim of the New 
Orleans “bowl.” 

Figure 8-2. Map of estimated flood depths in New Orleans Source: FEMA

In all areas affected by flooding resulting from Hurricane Katrina, property 
elevation was the key difference in the magnitude of damage. The higher the 
property grade elevation, the lower the flood damage. In areas of New Orleans at 
the same grade elevation, buildings elevated on crawlspaces generally sustained 
less flood damage than slab-on-grade buildings. In addition, flooding was 
exacerbated by the long-term subsidence of the New Orleans area, which has 
resulted in some areas being below sea level. Scientists estimate that the rate 
of subsidence of Southern Louisiana is as much as 3 feet every 100 years, or a 
little less than a 1/2 inch per year (National Geographic News, “New Orleans — A 
Man Made Disaster?”, October 13, 2005, National Geographic Society, Washington, 
DC).

8.2 Floodplain Management Issues Related to Levees/Floodwalls  in the New 
Orleans Area

Floodplain mapping in the New Orleans area has historically been based on an 
assumption that the area was protected by the USACE-certified levee system, 
which was developed over several decades beginning in the  920s. This assumption 
led to floodplain regulations that allowed building construction to occur at or 
below sea level with no accommodations made for the possibility of riverine or 
coastal flooding. A detailed discussion of the New Orleans levee system and the 
floodplain management issues related to the levees/floodwalls is provided in 
Sections 8.2.1 and 8.2.2, respectively.

8.2.1 History of the New Orleans Levee System

Based on information provided by the New Orleans District of the USACE, the New 
Orleans levee/floodwall system was constructed in two parts. The first part, the 
Mississippi River Levee System (MR&T), was designed to protect the city from a 
flood flow of 3 million cubic feet per second from the Mississippi River, and 
was constructed under the authority of the Flood Control Act of 1928 and 
subsequent amendments. The MR&T system in the New Orleans District extends along 
the west bank of the Mississippi River from the vicinity of Black Hawk, 
Louisiana, generally southward to the vicinity of Venice, Louisiana, and on the 
east bank from Baton Rouge, Louisiana, to Bohemia, Louisiana.

The second part of the levee system, the Lake Pontchartrain and Vicinity 
Hurricane Protection Project (LP&V-HPP), was designed to protect residents 
between Lake Pontchartrain and the Mississippi River levee from surges in Lake 
Pontchartrain and Lake Borgne by storms up to a fast-moving Category 3 
hurricane. The LP&V-HPP was authorized by the Flood Control Act of 1965, the 
Water Resources Development Act of 1974, and subsequent amendments. The LP&V-HPP 
is located in St. Bernard, Orleans, Jefferson, and St. Charles Parishes, 
generally in the vicinity of the City of New Orleans, and between the 
Mississippi River and Lake Pontchartrain. The LP&V-HPP system also protects 
residents from surges in the canals, which extend from Lake Pontchartrain to the 
south. These canals have been in existence since the late 1800s and were 
originally designed to provide navigation and drainage of the lowest parts of 
the City of New Orleans. The LP&V-HPP system is composed of numerous levees and 
flood walls, including the 17th Street Canal and London Avenue Canal 
levees/floodwalls. 

8.2.2 Floodplain Mapping and Building Construction within the New Orleans Levee-
Protected Area

The two-part New Orleans levee/floodwall system was certified by the USACE as 
providing at least 100-year flood protection, in accordance with the NFIP 
requirements. Due to this certification, the FIRMs for the area, which are the 
basis for the flood insurance and floodplain management, did not reflect 
flooding from the Gulf of Mexico, Lake Pontchartrain, or the Mississippi River. 
Although the FIRMs did reflect some flooding in the areas protected by the 
levee/floodwall system, the source of this flooding was not from a 
levee/floodwall breach, but from rainfall within the protected ‘interior’ area, 
generating runoff and producing localized flooding. This interior flooding was 
to be removed by a network of pumps supported by backup power in the case of 
major power outages. As a result, the FIRMs showed some of the interior areas 
either as having no floodplain or with a floodplain reflective of local runoff 
or ponding and awaiting removal outside the levee/floodwall system by the 
pumping network. 

The 100-year flood elevations, or BFEs, in the interior areas protected by the 
levee/floodwall system were low compared to the actual flood elevations 
experienced as a result of Hurricane Katrina. A review of the FIRMs for 
neighborhoods observed by the New Orleans Flood Team indicated that most of the 
BFEs were at approximately sea level elevation, with some actually below sea 
level. This meant that, in areas of New Orleans that were protected by the 
certified levee/floodwall system, building development could occur below sea 
level while still being at or above the BFE and compliant with the NFIP. 

Examples of the disparity between the BFE as compared to the elevation of the 
levee/floodwall and the flood elevations observed due to Hurricane Katrina were 
found in many neighborhoods of the city. Many buildings were newer construction 
and were fully compliant with the NFIP and the local building code. In many 
instances, homeowners had added freeboard to elevate their homes higher than the 
BFE by 1 or 2 feet as added protection from the flood source. They understood 
they were vulnerable to interior flooding. Yet many of these residential 
buildings still experienced 3 to 5 feet of flooding above their first floor 
elevation as a result of the levee/floodwall breach (see Figure 8-3). Homeowners 
interviewed in these neighborhoods stated that they did not realize that a 
breach of the levee/floodwall system could allow such major flooding to occur.

Figure 8-3. Photo of a residential building constructed approximately 1 foot 
above the BFE in accordance with current codes. Note flood depths were even with 
the top of the garage door, or about 3-5 feet above the first floor (red line).

Aggravating this issue was the change in building construction techniques in the 
New Orleans area since the construction of the levee/floodwall system. 
Historically, New Orleans residential construction often incorporated elevation 
where the first finished floor was elevated several feet above grade (see Figure 
8-4, upper left). The area below the first finished floor was unfinished and was 
used as a crawlspace or, if high enough, a garage area. When floods occurred, 
the first finished floor remained dry, the lower unfinished area was easily 
cleaned after the flood, and flood damages were minimal. More recent New Orleans 
residential construction has consisted almost exclusively of either slab-on-
grade foundations or slight elevations above grade with a minimal crawlspace, 
both reflecting BFEs based only on local drainage flooding in the protected 
areas shown on the FIRM (see Figure 8-4, lower right). This recent change in 
construction techniques, combined with ongoing land subsidence, contributed to 
the magnitude of flood damage observed in New Orleans.

Figure 8-4. Photos of the omparison of building techniques in New Orleans. The 
older residence on the upper left has the first finished floor constructed 
several feet above grade. The newer residence on the lower right is constructed 
with a slab-on-grade foundation.

8.3 General Characterization of Flood Damage 

As discussed previously, most of the damage observed in the New Orleans area was 
non-structural and related to long-duration flood issues; only limited 
structural damage was observed. Damages to various building types were similar, 
with no significant difference in impacts observed between residential buildings 
and critical and essential facilities. Most observed buildings, including 
residential as well as critical and essential facilities, were constructed on 
vented crawlspaces or slab-on-grade foundations with wood-framed walls covered 
by brick veneer.

8.3.1 Structural Damage

Only minimal structural damage was observed in the majority of buildings in New 
Orleans as a result of flooding from Hurricane Katrina. There are two primary 
reasons for this observation. First, the flooding in New Orleans was caused by 
slow-moving floodwaters, which greatly reduced or eliminated the damaging 
effects of hydrodynamic forces and floodborne debris impacts on buildings. 
Second, the crawlspaces, foundation vents, garage bay doors, and other openings 
allowed hydrostatic pressures on walls and floors from floodwaters to equalize 
as floodwaters gradually rose and receded, which greatly reduced the net 
hydrostatic force on load-bearing walls, floors, and other structural elements. 
Although flood-related structural damage was typically minor, there were several 
significant ex­ceptions:

- First, the failure of the Industrial Canal (see Figure 8-5) and coastal levees 
produced intense flooding in eastern New Orleans and St. Bernard Parish, 
resulting in severe structural damage in the Lower Ninth Ward of New Orleans and 
Chalmette in St. Bernard Parish. Observations by the New Orleans Flood team 
indicated widespread destruction of residential buildings in the Lower Ninth 
Ward from high velocity floodwaters and strong winds, waves, and high 
floodwaters that knocked buildings off their foundations, collapsed load-bearing 
walls, and caused other structural failures. 

Figure 8-5. Photo of the Industrial Canal levee breach in New Orleans Source: 
LSU Hurricane Center 

Figure 8-6. Photo of structural damage to residential buildings (circle) in New 
Orleans located immediately behind the site of 17th Street Canal levee breach 
(arrow)

Figure 8-7. Photo of settlement cracks in upper floor wall of New Orleans 
residence due to subsidence/differential settlement of underlying foundation 
soils during long-duration flooding 

- Second, residential buildings sited immediately behind failed sections of 
levees or other flood control structures such as the  7th Street Canal levee 
breach suffered significant structural damage, failure of load-bearing walls, 
and excessive scour around slab foundations from large hydrodynamic forces 
generated by the levee breach (see Figure 8-6). However, these forces and 
impacts were quickly dissipated within a few blocks of the breach. 

- Third, buildings sited on poor foundation soils suffered significant 
structural damage and cracking of load-bearing walls and sagging floors due to 
subsidence or differential settlement of saturated soils that support one or 
more foundation walls and/or piers (see Figure 8-7). While most of the observed 
structural damages triggered by soil settlement or subsidence did not constitute 
an imminent danger of collapse, such damages (and the underlying soil problems 
behind them) typically require analysis by a foundation engineer and can be 
expensive to isolate and repair.

Visual observations of interior walls of both older (more than 50 years old) and 
newer (less than 5 years old) residential buildings showed little to no evidence 
of deterioration of the exposed portions of the structural wall studs due to 
long-duration flood exposure, except for some water staining and slight bowing 
of some sheathing boards (see Figures 8-8 and 8-9). However, moisture readings 
taken inside various residential buildings indicated that excess moisture 
remained trapped in the walls and floors following the flood. Continued 
entrapment of moisture within the wall and floor systems due to a lack of drying 
could induce rotting of the structural framing in the long term.

Figure 8-8. Photo of exposed wall studs and sheathing boards in 74-year-old New 
Orleans residential building, showing no significant deterioration from long 
duration flooding

Figure 8-9. Photo of exposed wall studs and sheathing boards in 2-year-old New 
Orleans residential building, showing no significant deterioration from long-
duration flooding.

8.3.2 Non-Structural Damage

Widespread non-structural damage occurred to areas in and around New Orleans 
that were impacted by long-duration flooding. Unlike other hurricane-impacted 
areas, where residents could access their buildings relatively quickly after the 
flood event, the residents of New Orleans who were protected by the 
levee/floodwall system were unable to access buildings for several weeks because 
of prolonged flood inundation. As a result, the extent of interior damage was 
larger than damages observed in previous hurricane events. 

Typical flood damages to buildings included damaged or destroyed interior 
drywall, plaster, fiber insulation, metal studs, flooring, wall finishes, 
carpets, and furniture (see Figure 8-10). Mold growth observed in flooded 
residences varied from light to extensive, depending on the depth of flooding, 
the type of interior wall finishes, and the amount of drying that occurred after 
the floodwaters receded (see Figures 8-10 and 8-11). Additionally, floodwaters 
carried bacterial and chemical pollutants into buildings, thereby contaminating 
porous building materials (refer to Section 8.4.2).

Figure 8-10.Photo of typical interior flood damage to residential building in 
New Orleans, showing extensive mold growth (circle)

Figure 8-11. Photo of typical interior flood damage to residential building in 
New Orleans, showing light mold growth (compare to Figure 8-10)

Several fire stations in New Orleans suffered flood damage to garage bay doors 
(see Figure 8-12). The fire stations in New Orleans observed by the MAT did not 
contain fire trucks or other heavy equipment; these appear to have been 
relocated prior to the flood. Many New Orleans hospitals suffered interior 
damage such as collapsed drop ceilings due to a loss of emergency power 
generators, which shut down HVAC systems used to control temperature and 
humidity. In some hospitals, the loss of emergency generators resulted from 
flooding of the generator controls or the fuel storage tanks (see Figure 8-13). 
However, in most hospitals, the loss of emergency generators occurred as a 
result of mechanical breakdown from extended use following Hurricanes Katrina or 
Rita.

Figure 8-12. Photo of damage to garage bay doors at fire station in New Orleans. 
The door on the right was pushed in by flooding; the door on the left appears to 
have been pulled open from the outside by looters.

Figure 8-13. Photo of flooded emergency generator at hospital in New Orleans 
(note flood line in red)

8.4 Long-Duration Flood Impacts on Buildings 

Damage from long-duration exposure to floodwaters often lies concealed within 
the building envelope and within wall cavities. The level of the water 
intrusion, the concentration of floodborne contaminants, and the length of time 
until floodwaters recede are important factors influencing the potential 
salvagability of building materials and personal property. In general, the long-
duration flood damages observed in the New Orleans area were primarily to porous 
building materials, including wall sheathing, ceilings, and floor coverings. 
These materials experienced deterioration from being saturated and were 
impregnated with contami­nated floodwater. 

In order to examine the effects of long-duration flooding on porous building 
materials, members of the New Orleans Flood Team conducted field readings and 
took building material samples for laboratory testing from seven residential 
buildings and two fire stations in the New Orleans area from October 6 to 8, 
2005. The buildings sampled were selected from among the 23 residential 
buildings and critical and essential facilities visited in the New Orleans area 
from October 4 to 8, 2005 (Figure 8-1) to reflect a variety of observed flood 
depths, building types, and potential contamination levels. The sampling 
undertaken was for informational purposes only and was not intended as a 
statistical representation of conditions throughout the City. Table 8-1 
summarizes the buildings sampled for field readings and laboratory testing. 
Specific information on the field readings and laboratory tests is provided in 
Sections 8.4.1.2 and 8.4.2.1. 

[Begin Table}
Table 8-1. Summary of Buildings Sampled and Tests Conducted

Residence at Elysian Fields
Interior Flood Depth (feet): 6.0 - 8.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): yes
Material Moisture Contents (Section 8.4.1.2): yes 
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes 
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes 

Residence at General Diaz Street
Interior Flood Depth (feet): 6.0 - 7.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): yes 
Material Moisture Contents (Section 8.4.1.2): yes 
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes 
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes 

Residence at Memphis Street
Interior Flood Depth (feet): 6.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): yes 
Material Moisture Contents (Section 8.4.1.2): yes 
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes 
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes 

Residence at Savoie Court
Interior Flood Depth (feet): 0.83 - 1.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): yes 
Material Moisture Contents (Section 8.4.1.2): yes 
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes 
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes 

Residence at Munster Boulevard
Interior Flood Depth (feet): 7.5
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): no
Material Moisture Contents (Section 8.4.1.2): yes
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes

 
Residence at Cleary Avenue
Interior Flood Depth (feet): 0.83 - 1.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): yes
Material Moisture Contents (Section 8.4.1.2): yes
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes 

Residence at Octavia Street
Interior Flood Depth (feet): 5.5
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): no
Material Moisture Contents (Section 8.4.1.2): yes
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes

Fire station at Louisiana Avenue
Interior Flood Depth (feet): 3.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): no
Material Moisture Contents (Section 8.4.1.2): yes
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes

Fire station at South Carrollton Avenue
Interior Flood Depth (feet): 2.0 - 3.0
Summary of Readings and Tests Conducted:
Specific Humidity (Section 8.4.1.2): no
Material Moisture Contents (Section 8.4.1.2): yes
Biological Contaminants (Sections 8.4.2.1 and 8.4.2.2): yes
Chemical Contaminants (Sections 8.4.2.3 - 8.4.2.6): yes

[End Table]

8.4.1 Deterioration of Building Materials from Long-Duration Flooding

8.4.1.1 Mechanics of Deterioration

In general, differing types of long-duration flood damage occur above and below 
the high water mark. Above the high water mark, moisture damage occurs as the 
result of capillary action, water vapor migration, and condensation. Below the 
high water mark, damage occurs from solvent action, corrosion, waterborne 
solids, contaminants, and bacterial degradation. 

- Capillary action: Visual observations of interior walls and other building 
materials in various residential buildings and critical and essential facilities 
in the New Orleans area showed evidence of capillary action above the water 
line. A summary of specific humidity readings taken by the New Orleans Flood 
Team inside and outside the selected residential buildings is provided in Table 
8-2. The specific humidity readings confirmed field observations that the 
interiors of the homes were consistently wetter than the outdoors and that 
opening exterior doors and windows would facilitate drying of building materials 
within homes. Material moisture content readings taken in various residential 
buildings and critical and essential facilities also showed elevated moisture 
contents in the drywall and/or plaster in the first floors of the buildings when 
compared to the upper floors. 

- Water vapor migration: Visual observations of building materials in various 
residential buildings and critical and essential facilities in the New Orleans 
area showed evidence of water vapor migration above the water line. Interior 
doors and cabinet doors and drawers constructed of laminated wood products and 
other porous building materials were swollen shut and difficult to open as a 
result of water vapor migration (see Figure 8-14).

- Solvent action:  Visual observations of interior walls of both older (more 
than 50 years old) and newer (less than 5 years old) residential buildings and 
various critical and essential facilities in the New Orleans area showed little 
to no evidence of deterioration by solvent action above or below the water line.

- Corrosion: Visual observations of metal con­nectors and electrical components 
in both older (more than 50 years old) and newer (less than 5 years old) 
residential buildings and various critical and essential facilities in the New 
Orleans area showed little to no evidence of deterioration by corrosion above or 
below the water line.  This may be explained by the generally low salinity of 
the floodwaters that impacted the New Orleans area follow­ing Hurricane Katrina.

[Begin Text Box]

Capillary action. Capillary action, commonly referred to as “wicking,” is the 
process by which water molecules adhere to surfaces and climb upward through 
ma­terials against gravity.

Water vapor migration. Water vapor migration through the interior of a building 
is invisible and often overlooked. Water vapor affects materials such as wood 
and paper, which increase or decrease in size (i.e., swell or shrink) based on 
their moisture content.

Solvent action. Water is a powerful and effective solvent and can dissolve some 
paper products such as drywall (gypsum board) paper.

Corrosion. Metals of differing composition in contact with one another in the 
presence of water or water vapor are vulnerable to corrosion. Corrosion is 
predictable. For example, when copper electrical wire con­tacts a steel screw, 
the more chemically active metal corrodes. Corrosion increases as the salinity 
of the water increases.

[End Text Box]

[Begin Table]
Table 8-2. Summary of Specific Humidity Readings (grains per pound)

Property: Residence at Elysian Fields
Outside: 102.2
Crawlspace: 119.0
Inside (1st Floor): 115.5
Inside (2nd Floor): -
Inside (3rd Floor): -

Property: Residence at General Diaz Street
Outside: 127.6
Crawlspace: 133.0
Inside (1st Floor): 145.2
Inside (2nd Floor): -
Inside (3rd Floor): -

Property: Residence at Memphis Street
Outside: 112.2
Crawlspace: -
Inside (1st Floor): 132.0
Inside (2nd Floor): 138.6
Inside (3rd Floor): 153.3

Property: Residence at Savoie Court
Outside: 80.6
Crawlspace: -
Inside (1st Floor): 85.8
Inside (2nd Floor): -
Inside (3rd Floor): -

Property: Residence at Cleary Avenue
Outside: 91.2
Crawlspace: -
Inside (1st Floor): 100.8
Inside (2nd Floor): -
Inside (3rd Floor): -
[End Table]

Figure 8-14. Photo of kitchen cabinet doors above the flood level were damaged 
from the excessive moisture in the house from long-duration flooding.

8.4.1.2 Damage Observations and Flood Resistance of Building Materials in the 
New Orleans Area

Floodwater damage to specific building materials depends on a variety of 
factors, including the depth, velocity, and composition of the floodwater, and 
the type, design, age, and construction methods of the building materials. For 
vulnerable building materials, flood damage is typically a progressive condition 
(the longer materials remain wet, the greater the damage that occurs). Some 
floodprone materials reach a point-of-no-return when exposed to floodwaters, 
after which salvage attempts are futile. Examples of such floodprone materials 
include laminated wood products used for interior doors and cabinets, which will 
swell and deteriorate, and hardwood flooring, which will warp. A summary of 
typical building materials observed in New Orleans and their basic flood 
resistance is described in the bullets that follow.  

- Exterior walls. Many of the exterior walls in residential buildings observed 
in New Orleans were constructed of brick veneer or stone, which are durable 
porous materials that are resistant to flooding damage and can frequently be 
cleaned with minimal difficulty. Other observed exterior wall materials that can 
frequently be washed and cleaned included other durable porous surfaces, such as 
engineered stone and stucco, and nonporous surfaces, such as vinyl and aluminum 
siding.

- Wood framing. Of the available wood products, solid dimensional lumber is 
typically the most resistant to water, while materials made from chips or 
oriented strands of wood are most vulnerable due to additional points for 
moisture intrusion. Laminated plied materials, such as exterior-grade plywood 
with waterproof adhesives, are reasonably water-resistant. Other materials, such 
as OSB, are less water-resistant. Some wood products are pressure-treated with 
chemical agents that resist microbial attack and can improve flood resistance.
 
When moisture content in various wood products was measured and compared in 
one New Orleans residence, the moisture content in the OSB was twice as high as 
in the pressure-treated plywood even though the plywood was the lowest course of 
sheathing and the OSB sheathing course was located above it. The Flood Team 
observations indicate that:

1. If not permitted to adequately dry, OSB retains moisture longer, and can be 
more vulnerable to microbial attack, than plywood.

2. OSB requires either extended drying periods when drying naturally or higher 
capacity drying equipment when structural drying is performed mechanically. 

Visual observations of interior walls and floors of various residential 
buildings and critical and essential facilities showed little to no evidence of 
deterioration of the exposed portions of the wood framing due to long-duration 
flood exposure, except for some water staining and slight bowing of some 
sheathing boards in residential buildings. Visible fungal growth was noticeable 
when inspecting the wood in the crawlspaces under several residential buildings; 
however, some of the growth appears to have existed prior to the flood.

- Insulating materials. Typical insulating materials are fibrous and need to be 
replaced after being impacted by floodwaters. A variety of insulating materials 
were found within residential buildings in New Orleans. While older dwellings 
had no insulation or mineral wool insulation, the predominant insulating 
material found in one- and two-family dwellings was paper-faced fiberglass 
insulation. After the floodwaters receded, flooded fiberglass insulation 
retained water, and the moisture “wicked” farther up into the paper due to 
capillary action. 

- Interior wall materials. The most common interior wall material observed in 
newer New Orleans residences was drywall. Dry­wall (gypsum board) consists of 
gypsum sandwiched between paper layers. In residential buildings that were more 
than 50 years old, drywall and/or thin coats of plaster were layered over the 
original lath and plaster walls. When flooded, drywall is typically subject to 
deterioration by softening due to “wicking” and increased vulnerability to 
impact damage. Another common interior wall material observed in New Orleans was 
plaster. Plaster begins as a mixture of dry components that crystallize through 
chemical reaction when water is added. Plaster is applied in layers to a 
substrate of wood, metal, or rock lathe. Although plaster typically absorbs less 
water than drywall, plaster is a dense material, which is slow to dry after 
wetting. 

Observations by the New Orleans Flood Team did not indicate evidence of drywall 
deterioration from softening due to solvent action.  However, both the drywall 
and the plaster in buildings impacted by floodwaters experienced “wicking,” 
which led to extensive fungal growth and entrapment of floodborne contaminants 
within the drywall materials (refer to Section 8.4.2 for details).

- Wall coverings and coatings. Depending on the source(s) of moisture, wall 
coverings and coatings can either protect surfaces from moisture intrusion or 
exacerbate damage by trapping moisture within the materials. Observations of 
flooded buildings in New Orleans indicated most surfaces covered by common 
household paints were not resistant to floodwater damage. In addition, wallpaper 
paste found in some residences was dissolved by floodwaters from solvent action 
and facilitated widespread fungal growth (refer to Sec­tion 8.4.2.2 for 
details).

- Interior doors and cabinets. The majority of interior doors and cabinets 
observed in New Orleans buildings were constructed of laminated wood products. 
The water vapor migration that occurred throughout many building interiors 
caused countless laminated wood passage doors, and cabinet doors and drawers to 
swell shut (see Figure 8-14). 

- Floors and floor coverings. Floors and floor coverings observed in New Orleans 
included bare concrete, hardwood, laminate, carpeting, vinyl tiles, and 
linoleum.  Bare concrete floors found in fire station apparatus bays were 
typically most resistant to flood damage. By contrast, the long-duration 
flooding in New Orleans led to warping and buckling of hardwood and laminate 
flooring from moisture absorption. Vinyl and linoleum floor coverings observed 
in most buildings did not experience significant damage, except for some tiles 
in older buildings that were found to be loose or had curled edges; however, the 
coverings can entrap moisture that could damage the underlying wood sub-floor.  
Also, many older (pre-1970s) vinyl and linoleum flooring products, such as 9-
inch square tiles and adhesives, often contain asbestos.

- Framing connections. Metal framing connectors and fasteners observed in the 
New Orleans buildings did not experience significant long-duration flood damage 
as a result of corrosion. 

- Utility systems. As with connections, most plumbing and plastic-encased 
electrical lines observed in the New Orleans buildings did not experience 
significant long-duration flood damage as a result of corrosion. However, other 
flooded utility lines and associated small equipment, such as HVAC ductwork and 
electrical receptacles, experienced greater flood damage. The New Orleans Flood 
Team observed furnaces and air conditioning units located in attic spaces, as 
well as multi-story dwellings where condensing coils were externally elevated 
and water heaters, furnaces, air conditioners, and laundry rooms were located on 
upper levels. These measures resulted in a reduction or elimination of damage to 
the utility equipment and appliances.

[Begin Text Box]
Specific Humidity and Drying Flooded Buildings 

After hurricanes, residents are generally urged to open their buildings to dry 
out building materials as soon as possible. Relative humidity (which changes 
according to air temperature) has been used in the past to measure progress and 
make decisions regarding post-flood building drying. However, relative humidity 
is an inaccurate measurement and should be abandoned in favor of using specific 
(or absolute) humidity (which is a measure of the actual moisture content, 
regardless of temperature). When determining the extent of drying in a building 
following a flood, temperature and relative humidity readings should be taken 
inside and outside of the building in order to determine the specific humidity 
readings inside and outside the building. These readings can be obtained by 
using tables or charts that convert temperature and relative humidity to 
specific humidity, or by means of special equipment such as a commercially-
available moisture meter.

When the specific humidity inside the building is greater than the specific 
humidity outside, natural processes such as opening the windows and doors can 
be used to facilitate drying inside the building. By contrast, when the specific 
humidity inside the building is less than the specific humidity outside, 
artificial means such as fans or drying equipment should be used to facilitate 
drying inside the building. It is important to note that the comparative 
specific humidity readings outside and inside the building should be taken at 
about the same time, and that the comparative readings and the moisture 
reduction methods employed in a given building are subject to change during the 
course of the drying process.

[End Text Box]

8.4.2 Long-Duration Flood Impacts from Contamination 

The extent and duration of the flooding that impacted New Orleans following 
Hurricane Katrina gave rise to numerous questions and concerns regarding 
hazardous materials that might have been present in the floodwaters. In an 
effort to address these questions and concerns, the U.S. Environmental 
Protection Agency (USEPA), in cooperation with the Louisiana and Mississippi  
Departments of Environmental Quality, the USGS, and NOAA, mobilized a 
coordinated effort to sample standing floodwater remaining in the impacted area 
as well as sediments and air.

According to the USEPA website 
(http://www.epa.gov/katrina/testresults/katrina_env_assessment_summary.htm), the 
USEPA collected the following samples and obtained the following results:

- Floodwater samples. Floodwaters in the east bank of the Greater New Orleans 
area were extensively tested. Nearly 400 water samples were collected by the 
Louisiana Department of Environmental Quality (LDEQ) and USEPA to represent the 
flooded areas and floodwaters from these areas that were pumped to Lake 
Pontchartrain when the areas were dewatered. Each of these samples was analyzed 
for nearly 200 chemicals and fecal coliform bacteria. The results indicated 
average concentrations of chemicals were below levels of concern for short-term 
(i.e., 90 days) dermal contact and incidental ingestion. However, numerous 
floodwater samples revealed elevated bacteria levels from floodwaters that had 
mixed with sewage collection system waters. According to the USEPA, the 
remaining floodwaters were removed from the New Orleans area on October 11, 
2005, and thus no longer served as a source of exposure to residents returning 
to impacted areas. 

- Sediment samples. From September 10 through October 14, 2005, USEPA collected 
sediment samples at 430 sites in the streets and public areas of Jefferson, 
Orleans, Plaquemines, and St. Bernard Parishes. The USEPA’s sampling procedures 
specified that efforts were to be made to bias the samples toward areas that 
were more likely to contain elevated levels of contamination such as areas that 
contained oily sediments. Each sample was tested for fecal coliform bacteria and 
about 200 different chemicals, including volatile organic compounds (VOCs), 
semi-volatile organic compounds (SVOCs), metals, pesticides, herbicides, 
polychlorinated biphenyls (PCBs), and hydrocarbons. The results indicated that a 
variety of chemicals were detected in the sedi­ments. The most frequently 
detected chemicals included some metals, hydrocarbons, and, to a lesser extent, 
pesticides. These levels are consistent with the results that would be expected 
in a densely populated urban area and are similar to the historical levels found 
in these parishes before Katrina, and to other urban areas throughout the 
nation. The majority of chemicals detected were below levels of health concern. 
However, there were some localized areas with levels of arsenic and petroleum 
hydrocarbons that exceeded both LDEQ’s Risk Evaluation/Corrective Action Program 
(RECAP) and USEPA’s risk criteria (e.g., range of   in  ,000,000 to   in  0,000 
risk of an individual developing cancer over a lifetime), based on long-term (30 
years) residential exposure assumptions. The levels of fecal coliform bacteria 
and petroleum hydrocarbons in the sediments also exceeded health screening 
values; however, these levels are expected to naturally decrease over time. 
Subsequent data from samples collected in November 2005 indicate that the 
highest arsenic concentrations were found in samples taken from golf courses and 
are associated with herbicides. Composite samples collected in February 2006 
indicate that the elevated arsenic detections not on golf courses were isolated 
and not indicative of larger areas of contamination that might pose a chronic 
health risk.

- Air samples. LDEQ and USEPA conducted extensive air sampling in the areas 
impacted by Hurricane Katrina. All of the results collected to date for ambient 
air quality samples appear to be typical for this region of the state, and are 
below any levels of health concern.

In an effort to determine if contaminants were present in structures after the 
floodwaters receded, seven residential structures and two critical and essential 
facilities (fire stations) were visually inspected and samples were collected. 
The focus of the site inspections for the New Orleans Flood Team was to assess 
and evaluate opportunities for flood restoration; the sampling was not intended 
to be statistically representative of contamination in the impacted area. Sample 
collection was limited to public buildings or structures where permission had 
been granted by the owners. Wherever possible, a sample of flood residue in the 
form of wet sludge or dried sediment was collected from inside the structure 
(see Figure 8-15). Additional samples, primarily of wall materials, were also 
collected. An effort was made to collect samples of materials from below the 
water line and comparison samples from above the water line (see Figure 8-16). 
See Appendix I for a detailed description of sampling and analytical methods.

Figure 8-15. Photo of flood residue and buckled floor observed on General Diaz 
Street. A sample of the flood residue was collected for analysis. 

Figure 8-16. Photo of where samples were collected from wall materials both 
above and below the waterline as shown on this wall of a house on Memphis 
Street. Where practical, samples were collected from surfaces that were already 
substantially damaged or scheduled for tear-out.

Analytical parameters were chosen following a review of the USEPA floodwater and 
sediment contaminant data from the New Orleans area. Unless the sample volume 
was insufficient to support multiple analyses, each sample was subjected to the 
following analyses: 

Biological Contaminants

- Bacteria. Overall quantification and breakdown by Gram Negative and Gram 
Positive types. Refer to Section 8.4.2.1 for details.

- Fungal. Identification of fungal (mold) materials. Refer to Section 8.4.2.2 
for details.

Chemical Contaminants 

- Heavy metals. Thirteen EPA and Occupational Safety and Health Administration 
(OSHA) priority element pollutants as described in the Clean Water Act. Refer to 
Section 8.4.2.3 for details.

- Hydrocarbons. Diesel range organics (DROs) that were likely to be left after 
the floodwaters had receded and evaporation had taken place. Refer to Section 
8.4.2.4 for details.

- Pesticides. Organochlorine compounds that were less likely to be diluted than 
the water soluble organophosphates that are used today. Refer to Section 8.4.2.5 
for details.

- PCBs. Polychlorinated biphenyls are persistent chemicals that were often used 
in transformer oils and in other industrial processes. Refer to Section 8.4.2.6 
for details.

A total of 9 water/sludge samples and 38 wall material samples were collected 
for analysis. Table 8-3 presents an overall review of the samples that were 
collected, as well as significant highlights of the test results related to each 
building. A review of the sample results indicated the biologi­cal and chemical 
contaminant levels were consistent with the USEPA's floodwater and sediment 
sample results. Refer to the USEPA website for details 
(http://www.epa.gov/katrina/testresults/katrina_env_assessment_summary.htm). 
Details on each of the biological and chemical parameters tested are provided in 
Sections 8.4.2.1 through 8.4.2.6. The detailed sample results, including an 
interpretive summary chart with critical information related to each type of 
ana­lytical data, laboratory quality control information, and notes regarding 
any limitations on the sample information, are also presented in Appendix I.

[Begin Table]

Table 8-3. Highlights of the Biological and Chemical Contaminant Sampling 
Results 

Building Sampled: Residence at Elysian Fields
Number of Samples: Eight samples were collected from inside and outside the 
house. There was sufficient sample volume for all of the samples to be analyzed 
for all six contaminant types noted on the previous page. However, one sludge 
sample was too wet for mold analysis.
Highlights: 
1. Extremely high levels of bacterial contamination in most water-impacted 
areas.
2. Significant mold contamination on wall materials above the water line. 
Chaetomium is the dominant fungal type in samples both above and below the water 
line. Chaetomium also recovered from unimpacted second floor.
3. Above average levels of arsenic, beryllium, cadmium, chromium, copper, lead, 
nickel, selenium, silver, and zinc in interior and exterior samples.
4. Average levels of DROs in the flood damaged areas, with above average levels 
in the exterior dry sludge.
5. Above average levels of DDt and heptachlor.
6. No detectable levels of PCBs. 

Residence at General Diaz Street
Number of Samples: Four samples were collected from inside the structure. One 
wall sample was not large enough for the mercury, DROs, pesticides, or PCBs 
analyses to be completed. Also, the sludge sample was too wet for mold analysis.
Highlights: 
1. Extremely high levels of bacterial contamination in all water-impacted areas. 
2. Significant mold contamination on wall materials above the water line. 
Limited mold growth from samples below the water line. Aspergillus/ Penicillium 
and Chaetomium flourishing above the water line.
3. Above average levels of arsenic and nickel in interior wet sludge sample, 
and above average level of beryllium in wall sample above water line. 
4. Above average levels of DROs. 
5. Above average levels of chlordane, DDt, dieldrin, and heptachlor. 
6. no detectable levels of PCBs. 

Building Sampled: Residence at Memphis Street 
Number of Samples: Four samples were collected from inside the structure. two 
wall samples were not large enough for the DROs, pesticides, or PCBs analyses to 
be completed. 
Highlights: 
1. Moderate to extremely high levels of bacterial contamination in all water-
impacted areas.
 2. Mold contamination present in dry sludge and wall samples above and below 
the water line. Aspergillus /Penicillium and Chaetomium dominate samples above 
the water line, but also the wood stud samples below the water line. 
Stachybotrys present in the sludge.
3. Above average levels of arsenic, beryllium, cadmium, chromium, copper, lead, 
selenium, silver, and zinc in interior dry sludge sample. 
4. Below average levels of DROs. 
5. No detectable levels of pesticides. 
6. No detectable levels of PCBs. 

Building Sampled: Residence at Savoie Court
Number of Samples: Nine samples were collected from inside the structure. Four 
wall samples were not large enough for heavy metals, DROs, pesticides, or PCBs 
analyses to be completed.
Highlights: 
1. Extremely high levels of bacterial contamination in the majority of samples.
2. Significant mold contamination on all samples. Aspergillus/Penicillium and 
Chaetomium dominate samples from both above and below the water line.
3. Average to below average levels of most heavy metals. 
4. Below average levels of DROs.
5. Generally average levels of pesticides, except for an above average level of 
dieldrin in a wall sample above the water line.
6. No detectable levels of PCBs.

Building Sampled: Residence at Munster Boulevard
Number of Samples: Three samples were collected from inside and outside the 
structure. The sludge sample was too wet for mold analysis.
Highlights: 
1. Extensive to extremely high levels of bacterial contamination in all water-
impacted areas. 
2. Significant mold contamination on the wall below the water line and the 
exterior sludge. Stachybotrys in both sludge and wall material, below the water 
line.
3. Above average levels of beryllium in the exterior dry sludge sample. 
4. Average to below average levels of DROs.
5. Below average levels of pesticides in the interior and exterior samples. 
6. No detectable levels of PCBs.

Building Sampled: Residence at Cleary Avenue
Number of Samples: Nine samples were collected from inside the structure. Three 
samples were not large enough for the DROs, pesticides, or PCBs analyses to be 
completed, and one sample was not large enough for heavy metals analysis.
Highlights: 
1. Extensive to extremely high levels of bacterial contamination in most 
samples.
2. Significant mold contamination in wall samples above and below the water 
line. Substantial mold with Stachybotrys on both sides of the drywall and studs 
above the water line.
3. Average levels of most heavy metals.
4. Below average levels of DROs.
5. Below average levels of pesticides.
6. No detectable levels of PCBs.

Building Sampled: Residence at Octavia Street
Number of Samples: Four samples were collected from inside the structure.
Highlights: 
1. Extremely high levels of bacterial contamination in all water-impacted areas.
2. Significant mold contamination. Aspergillus/ Penicillium and Chaetomium 
dominates three of the four interior wall material samples. 
3. Above average levels of mercury in wall material above the water line.
4. Average levels of DROs.
5. Above average levels of chlordane and DDt in the drywall.
6. No detectable levels of PCBs.

Building Sampled: Fire station at Louisiana Avenue
Number of Samples: Three samples were collected from inside the structure. One 
wall sample was not large enough for DROs, pesticides, or PCBs analyses to be 
completed.
Highlights: 
1. Extensive to extremely high levels of bacterial contamination in all water-
impacted areas.
2. Significant mold contamination. Chaetomium in samples both above and below 
the water line.
3. Above average levels of arsenic, cadmium, chromium, copper, lead, silver, and 
zinc in dry sludge sample. Generally below average levels of heavy metals 
detected in the drywall samples.
4. Average levels of DROs.
5. Above average levels of chlordane in the drywall.
6. No detectable levels of PCBs.

Building Sampled: Fire station at South Carrollton Avenue
Number of Samples: Three samples were collected from inside the structure. One 
sample was not large enough for the DROs, pesticides, or PCBs analyses to be 
completed.
Highlights:
1. Extensive to extremely high levels of bacteria contamination in all water-
impacted areas.
2. Significant mold contamination. Stachybotrys found in sludge and wall 
materials below the water line.
3. Above average levels of antimony, arsenic, cadmium, chromium, copper, lead, 
nickel, silver, and zinc. 
4. Below average levels of DROs.
5. Below average levels of chlordane. 
6. No detectable levels of PCBs.

[End Table]

8.4.2.1 Bacterial Contamination

Floodwaters carry biological contamination in the form of bacteria, viruses, and 
parasites. Bacteria are one-celled microorganisms that are invisible to the 
naked eye. Following flooding, they are the first microorganisms to multiply. 
Bacteria pose a significant post-flood health threat. Some bacteria produce 
poisonous toxins that can cause diseases such as lockjaw and food poisoning in 
humans. Other bacteria produce enzymes that dissolve or destroy living cells, 
thereby damaging commercial goods and fouling surfaces. Also, bacterial growth 
on food and food handling equipment is a major source of disease.

A total of 47 material samples and   floodwater sample taken from nine buildings 
were analyzed for bacterial growth. Bacteria levels ranged from undetectable to 
“overloaded,” which is reported as 456,000 colony forming units per square 
centimeter (cfu/cm2). The majority of bacteria identified in the samples were 
Gram Negative Bacilli. Samples dominated by this bacteria type generally 
indicate contact with sewage or animal feces. The results are summarized in 
Table 8-4.

[Being Table}
Table 8-4. Total Bacteria Contamination Levels (cfu/cm2) by Materials and 
Moisture Level 

For cultural bacterial swab sample results:
White: Below the method detection limit (BMDL) is less than 18 cfu/cm˛.
Yellow: Moderate is between 18 cfu/cm˛ and 1,000 cfu/cm˛. 
Orange: Extensive is between 1,001 cfu/cm˛ and 20,000 cfu/cm˛.
Red: Extremely high is greater than 20,000 cfu/cm˛.

Building: Residence at Elysian Fields
Range of Values: Maximum
Wet Sludge: 40,600 red
Dry Sludge: 1,200 orange
Wall Materials Below Water Line: 41,346 red
Wall Materials Above Water Line: 456,000 red
Range of Values: Minimum
Wet Sludge: 40,600 red
Dry Sludge: 1,200 orange
Wall Materials Below Water Line: 7,460 orange
Wall Materials Above Water Line: BMDL white
Range of Values: Average
Wet Sludge: 40,600 red
Dry Sludge: 1,200 orange
Wall Materials Below Water Line: 22,420 red
Wall Materials Above Water Line: 234,334 red
 
Building: Residence at General Diaz Street
Range of Values: Maximum
Wet Sludge: 64,900 red
Dry Sludge: No Sample
Wall Materials Below Water Line: 183,000 red
Wall Materials Above Water Line: 41,500 red
Range of Values: Minimum
Wet Sludge: 64,900 red 
Dry Sludge: No Sample
Wall Materials Below Water Line: 20,200 red 
Wall Materials Above Water Line: 41,500 red 
Range of Values: Average
Wet Sludge: 64,900 red 
Dry Sludge: No Sample 
Wall Materials Below Water Line: 101,600 red 
Wall Materials Above Water Line: 41,500 red 

Building: Residence at Memphis Street
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: 590 yellow
Wall Materials Below Water Line: 381,000 red
Wall Materials Above Water Line: 544 yellow 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: 590 yellow 
Wall Materials Below Water Line: 381,000 red 
Wall Materials Above Water Line: 544 yellow 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: 590 yellow 
Wall Materials Below Water Line: 381,000 red 
Wall Materials Above Water Line: 544 yellow 

Building: Residence at Savoie Court
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: No Sample 
Wall Materials Below Water Line: 233,000 red 
Wall Materials Above Water Line: 242,000 red 
 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: No Sample
Wall Materials Below Water Line: BMDL white
Wall Materials Above Water Line: 27,000 red 

Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: No Sample
Wall Materials Below Water Line: 90,000 red 
Wall Materials Above Water Line: 134,500 red 

Building: Residence at Munster Boulevard
Range of Values: Maximum
Wet Sludge: 7,020 orange
Dry Sludge: 4,860 orange
Wall Materials Below Water Line: 456,000 red 
Wall Materials Above Water Line: No Sample
Range of Values: Minimum
Wet Sludge: 7,020 orange
Dry Sludge: 4,860 orange
Wall Materials Below Water Line: 456,000 red 
Wall Materials Above Water Line: No Sample 
Range of Values: Average
Wet Sludge: 7,020 orange
Dry Sludge: 4,860 orange
Wall Materials Below Water Line: 456,000 red 
Wall Materials Above Water Line: No Sample

Building: Residence at Cleary Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: 8,280 orange
Wall Materials Below Water Line: 404,000 red 
Wall Materials Above Water Line: 350,000 red 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: 8,280 orange
Wall Materials Below Water Line: BMDL white
Wall Materials Above Water Line: BMDL white
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: 8,280 orange
Wall Materials Below Water Line: 138,500 red 
Wall Materials Above Water Line: 98,483 red 

Building: Residence at Octavia Street
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: No Sample
Wall Materials Below Water Line: 251,000 red 
Wall Materials Above Water Line: 456,000 red 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: No Sample 
Wall Materials Below Water Line: 251,000 red 
Wall Materials Above Water Line: 168,000 red 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: No Sample 
Wall Materials Below Water Line: 251,000 red 
Wall Materials Above Water Line: 312,667 red 

Building: Fire station at Louisiana Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: 3,690 orange
Wall Materials Below Water Line: 327,000 red 
Wall Materials Above Water Line: 156,000 red 
Range of Values: Minimum
Wet Sludge: No Sample 
Dry Sludge: 3,690 orange
Wall Materials Below Water Line: 327,000 red 
Wall Materials Above Water Line: 156,000 red 
Range of Values: Average
Wet Sludge: No Sample 
Dry Sludge: 3,690 orange
Wall Materials Below Water Line: 327,000 red 
Wall Materials Above Water Line: 156,000 red 
 
Building: Fire station at South Carrollton Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: 2,460 orange
Wall Materials Below Water Line: 23,600 red 
Wall Materials Above Water Line: 6,130 orange
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: 2,460 orange
Wall Materials Below Water Line: 23,600 red 
Wall Materials Above Water Line: 6,130 orange
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: 2,460 orange
Wall Materials Below Water Line: 23,600 red 
Wall Materials Above Water Line: 6,130 orange

[End Table]

A number of patterns were observed in the bacterial sampling data. The strongest 
correlation was seen between wet materials and bacterial growth. Since most 
bacteria need a warm, moist environment to proliferate, the connection between 
elevated moisture levels and higher bacteria levels was expected. Table 8-4 
shows that, for the two facilities where both wet and dry flood residues were 
sampled, bacteria levels were higher in the wet sludge as compared to dry 
sludge. Similarly, with one exception (Elysian Fields residence), bacteria 
levels from the same wall were significantly higher in the samples of drywall 
collected from below the waterline as compared to samples collected from a level 
above the floodwater line.

As might be expected, only low levels of bacteria were identified in samples 
collected from relatively dry materials. Negligible levels were detected in 
samples collected from the unimpacted second floor at the Elysian Fields 
residence and in the drier materials in the Cleary Avenue and Memphis Street 
residences.

Bacteria levels were relatively high on the outer surface of exposed wooden 
studs. The sample results on the studs were consistent with those from the 
drywall with Gram Negative Bacilli dominating the results (samples 6379-16, 
6379-21, and 6379-37).

Bacterial growth appeared to be inhibited by fungal growth in numerous areas. 
Rampant fungal growth on the damp carpet and wallpaper in the living room of the 
Savoie Court residence may well account for the fact that bacteria were not 
detected in those areas (see Table 8-4). Bacterial levels were also very low in 
the samples of visible fungal growth that were scraped from the carpet and a 
dresser leg in the Savoie Court residence (samples 6379- 8, 6379- 9, 6379-24, 
and 6379-25) (see Figure 8-17). 

Figure 8-17. Photo of how bacteria levels were frequently found to be 
significantly lower in areas with rampant fungal growth. This pattern held true 
at the residence on Savoie Court, where fungal levels were extensive on the 
dresser and carpet near the door frame while the bacteria levels were negligible 
at these same locations.

8.4.2.2 Fungal Contamination (Mold)

Fungi feed on either living or dead organisms by absorbing nutrients from the 
environment around them. Fungi accomplish this by growing through and within a 
host substrate. Fungal growth and contamination is a secondary health risk 
following flooding; the floodwater acts as a source of moisture, “wicking” into 
materials by capillary action, and stimulating fungal growth. The presence of 
fungi can cause allergic reactions, athlete’s foot, ringworm, and infections of 
the skin and nails. 

A total of 44 material samples taken from 9 facilities were analyzed for fungal 
contamination. In most cases, the fungal types were dominated by 
Aspergillus/Penicillium or Chaetomium. These mold types are frequently found as 
initial and secondary colonizers of water-impacted build­ing materials. Various 
strains of Aspergillus/Penicillium and Chaetomium are linked to significant 
health problems. In addition to Chaetomium, a number of other mold types that 
are indicative of substantial water damage were detected. These included 
Stachybotrys and Memnoniella, which are also associated with serious health 
symptoms. Results are shown in Table 8-5. 

[Begin Table]
Table 8-5. Summary of Fungal Sampling Data

Legend: For fungal bulk sample results: 
White: No (#/#) No Organisms Detected (# of # samples)
Orange: Yes (#/#) Indicator Organisms associated with potentially significant 
health problems detected = Aspergillus/Penicillum (# of indicator organisms 
detected in # of total samples)

Yellow: Yes (#/#) Common Organisms associated with minor health problems/ 
allergies, including Ascospore, Basid­iospore, Cladosporium, Culvaria, 
Epicoccum, Fusarium, Myxomycete, Nigospora, Periconia and Smut (# of different 
common organisms detected in # of total samples)
Red: Yes (#/#) Target Organisms associated with potentially serious health 
problems 
detected; which include Chaetomium, Fusarium, Memnomiella, Stachybotrys and 
Trichoderma (# of different target organisms detected in # of total samples)
Light orange: Yes (#/#) Hyphae: growth structures in addition to spores detected 
(# of hyphae detected in # of total sam­ples)
Blue: Yes (#/#) Spores

Building Site: Residence at Elysian Fields
Sample Location: Dry Sludge
Indicator Organisms: No (1/1) white
Common Organisms: Yes (2/1) yellow
Target Organisms: No (1/1) white 
Hyphae: Yes (1/1) light orange
Sample Location: Wall Materials Below Water Line
Indicator Organisms: No (3/3) white
Common Organisms: Yes (2/3) yellow
Target Organisms: Yes (1/3) red
Hyphae: Yes (2/3) light orange
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (1/3) orange 
Common Organisms: Yes (4/3) yellow 
Target Organisms: Yes (3/3) red 
Hyphae: Yes (2/3) light orange 

Building Site: Residence at General Diaz Street
Sample Location: Dry Sludge
Indicator Organisms: No Sample
Common Organisms: No Sample
Target Organisms: No Sample 
Hyphae: No Sample 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: No (2/2) orange
Common Organisms: Yes (2/2) yellow
Target Organisms: No (2/2) white
Hyphae: No (2/2) white
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (1/1) orange 
Common Organisms: Yes (4/1) yellow
Target Organisms: Yes (1/1) red
Hyphae: Yes (1/1) light orange
 
Building Site: Residence at Memphis Street
Sample Location: Dry Sludge
Indicator Organisms: Yes (1/1) orange
Common Organisms: Yes (1/1) yellow
Target Organisms: Yes (2/1) red
Hyphae: Yes (1/1) light orange
Sample Location: Wall Materials Below Water Line
Indicator Organisms: Yes (1/2) orange
Common Organisms: Yes (1/2) yellow
Target Organisms: Yes (1/2) red
Hyphae: Yes (1/2) light orange
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (1/1) orange 
Common Organisms: No (1/1) white 
Target Organisms: No (1/1) white 
Hyphae: No (1/1) white 

Building Site: Residence at Savoie Court
Sample Location: Dry Sludge
Indicator Organisms: No Sample
Common Organisms: No Sample
Target Organisms: No Sample
Hyphae: No Sample 

Sample Location: Wall Materials Below Water Line
Indicator Organisms: Yes (3/3) orange
Common Organisms: Yes (1/3) yellow
Target Organisms: Yes (3/3) red
Hyphae: Yes (3/3) light orange
 
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (2/2) orange 
Common Organisms: Yes (1/2) yellow 
Target Organisms: Yes (1/2) red 
Hyphae: Yes (1/2) light orange 
 
Building Site: Residence at Munster Boulevard
Sample Location: Dry Sludge
Indicator Organisms: Yes (1/1) orange 
Common Organisms: Yes (5/1) yellow 
Target Organisms: Yes (1/1) red 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: No (1/1) orange 
Common Organisms: No (1/1) white
Target Organisms: Yes (2/1) red 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Above Water Line
Indicator Organisms: No Sample
Common Organisms: No Sample 
Target Organisms: No Sample 
Hyphae: No Sample

Building Site: Residence at Cleary Avenue
Sample Location: Dry Sludge
Indicator Organisms: No (1/1) white 
Common Organisms: Yes (4/1) yellow
Target Organisms: No (1/1) white 
Hyphae: No (1/1) white 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: Yes (3/3) orange 
Common Organisms: Yes (1/3) yellow 
Target Organisms: Yes (1/3) red 
Hyphae: Yes (3/3) light orange
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (4/4) orange 
Common Organisms: Yes (7/4) yellow 
Target Organisms: Yes (2/4) red 
Hyphae: Yes (3/4) 

Building Site: Residence at Octavia Street
Sample Location: Dry Sludge
Indicator Organisms: No Sample
Common Organisms: No Sample 
Target Organisms: No Sample
Hyphae: No Sample
Sample Location: Wall Materials Below Water Line
Indicator Organisms: No (1/1) white
Common Organisms: No (1/1) white
Target Organisms: Yes (1/1) red
Hyphae: (1/1) light orange
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (3/3) orange 
Common Organisms: Yes (5/3) yellow
Target Organisms: Yes (2/3) red
Hyphae: Yes (1/3) light orange 

Building Site: Fire station at Louisiana Avenue
Sample Location: Dry Sludge
Indicator Organisms: No (1/1) white 
Common Organisms: Yes (3/1) yellow 
Target Organisms: No (1/1) white 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: Yes (1/1) orange 
Common Organisms: Yes (1/1) yellow 
Target Organisms: Yes (1/1) red 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (1/1) orange 
Common Organisms: No (1/1) white 
Target Organisms: Yes (2/1) red 
Hyphae: Yes (1/1) light orange 
 
Building Site: Fire station at South Carrollton Avenue
Sample Location: Dry Sludge
Indicator Organisms: No (1/1) white 
Common Organisms: Yes (1/1) yellow 
Target Organisms: Yes (2/1) red 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: No (1/1) white 
Common Organisms: Yes (1/1) yellow 
Target Organisms: Yes (1/1) red 
Hyphae: Yes (1/1) light orange 
Sample Location: Wall Materials Above Water Line
Indicator Organisms: No (1/1) white 
Common Organisms: No (1/1) white 
Target Organisms: No (1/1) white 
Hyphae: No (1/1) white 
 
Totals
Sample Location: Dry Sludge
Indicator Organisms: Yes (2/6) orange 
Common Organisms: Yes (16/6) yellow 
Target Organisms: Y es (5/6) red 
Hyphae: Yes (5/6) light orange 
 
Sample Location: Wall Materials Below Water Line
Indicator Organisms: Yes (8/17) orange 
Common Organisms: Yes (9/17) yellow 
Target Organisms: Yes (11/17) red 
Hyphae: Yes (13/17) light orange 

Sample Location: Wall Materials Above Water Line
Indicator Organisms: Yes (13/16) orange 
Common Organisms: Yes (21/16) yellow 
Target Organisms: Yes (11/16) red 
Hyphae: Yes (9/17) light orange 

[End Table]

Substantial fungal contamination was observed in all of the inspected 
facilities. In the majority of inspected structures, fungal growth was observed 
to be more vigorous on porous contents (see Figures 8-18and 8-19 and porous wall 
finishes above the water line as compared to wall materials below the water 
line. In several houses, the fungal growth was rampant on surfaces high enough 
above the water line to suggest that the growth was supported by high humidity 
levels and/or condensation as compared to water “wicking” (see Figure 8-20). 
This was especially evident in the residence on Savoie Court, where the water 
level only reached approximately 18 inches above the floor. Even so, mold growth 
in this structure was extensive in many rooms extending all the way to the 
ceiling (see Figure 8-21. In addition, minor visible mold growth was observed on 
the concealed side of the drywall on the majority of the wall samples taken, 
even for samples where the exposed surface was covered with mold. However, 
sample results of materials inside the wall cavities confirmed the presence of 
fungal contamination inside the wall as well as on the exposed surfaces.

Figure 8-18. Photo of prolific mold growth was seen on porous contents in most 
inspected buildings.

Figure 8-19. Photo of the mold growth on the walls was generally much more 
vigorous above the floodwater level than below it. Sediments, heavy metal 
contamination, and oil film residue, as well as material moisture content and 
lack of exposure to air during flooding, may contribute to minimizing the fungal 
growth on the saturated wall materials.

Figure 8-20. Photo showing that in many buildings, the mold growth above the 
waterline appears to have been fueled by condensation of moisture in addition to 
water "wicking." The upper cabinets and kitchen ceiling in the building on 
General Diaz Street were well above the floodwater line, yet showed extensive 
fungal growth.

Figure 8-21. Photo showing that on Savoie Court, fungal growth was observed up 
to the ceiling on some walls, despite the fact that floodwaters only reached up 
18-24 inches. This wall showed thick mold growth both above and below the high 
water mark.

Fungal contamination was typically observed above the high water mark and was 
generally absent or significantly less vigorous below it. There is evidence in 
the technical literature that the dirt and sediment, which is present in the 
building materials after being saturated by floodwater, discourages fungal 
growth. Fungal growth may also have been discouraged below the high water mark 
by some of the residual contaminants in the wall materials, including pesticides 
and heavy metals, which are documented to have antifungal properties.

8.4.2.3 Heavy Metals

Heavy metals such as lead and mercury are natural components of the Earth’s 
crust that cannot be degraded or destroyed.  Heavy metals can be introduced into 
the water supply through industrial and consumer waste, or from acid rain 
breaking down soils and releasing heavy metals into lakes, rivers, and 
groundwater. These heavy metals can then be carried by floodwaters and spread 
over a wide area.

Thirty-six material and eight sludge samples collected from nine buildings were 
analyzed for the following 1 heavy metals: antimony, arsenic, beryllium, 
cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, 
and zinc. Because mercury is subject to a different analytical technique than 
the other metals, there was only enough sample volume in 40 of the samples to 
provide a reading for mercury. A summary of the maximum levels of heavy metals 
evaluated during the analysis of the samples collected from the New Orleans area 
is shown in Table 8-6. 

The results of Table 8-6 indicate the following:

- Levels of arsenic exceeded the 250 percent of the mean (average) values in a 
majority of the buildings sampled.
- Levels of beryllium, cadmium, chromium, copper, lead, nickel, silver, and zinc 
exceeded the 250 percent of the average values in three or more of the buildings 
sampled.
- Levels of antimony, selenium, silver, and thallium were below the method 
detection limit (BMDL) in a majority of the buildings sampled. 

The highest concentrations of heavy metals were typically encountered in the wet 
and dry sludge samples than in the wall materials. However, it is important to 
note that the number of available sludge sample results was relatively low 
compared to the number of available wall sample results. In addition, 
concentrations of heavy metals appeared to be higher in buildings located closer 
to Lake Pontchartrain and lower in buildings located farther away from the Lake 
Pontchartrain. These results suggest that the some of the heavy metal 
contaminants came from Lake Pontchartrain floodwater.

Heavy metals typically enter the human body via ingestion and inhalation. As 
trace elements, some heavy metals (e.g., copper, selenium, and zinc) are 
essential to maintain the metabolism of the human body. However, at higher 
concentrations, they can lead to poisoning. Heavy metals are particularly 
dangerous as they tend to bioaccumulate. Bioaccumulation means an increase in 
the concentration of a chemical in a biological organism over time, compared to 
the chemical’s concentration in the environment. Compounds accumulate in living 
things any time they are taken up and stored faster than they are broken down 
(metabolized) or excreted. Cadmium, lead, and mercury are considered toxic heavy 
metals. Exposure to high levels of heavy metals identified in Table 8-6 can have 
the following adverse health effects:

- Antimony: Exposure to high levels of antimony for short periods of time causes 
nausea, vomiting, and diarrhea. There is little information on the effects of 
long-term antimony exposure.

- Arsenic: Acute (short-term) arsenic poisoning may cause nausea, vomiting, 
diarrhea, weakness, loss of appetite, shaking, cough, and headache. Chronic 
(long-term) exposure may lead to a variety of symptoms, including skin 
pigmentation, numbness, cardiovascular disease, diabetes, and vascular disease. 
Arsenic is also known to cause a variety of cancers, including skin cancer (non-
melanoma type), kidney, bladder, lung, prostate, and liver cancer.

- Cadmium: Long-term exposure to cadmium is associated with renal dysfunction. 
High exposure may lead to obstructive lung disease and has been linked to lung 
cancer, although data concerning the latter are difficult to interpret due to 
compounding factors. Cadmi­um may also produce bone defects (osteomalacia, 
osteoporosis) in humans and animals.

- Chromium: Low-level exposure to chromium can irritate the skin and cause 
ulceration. Long-term exposure can cause kidney and liver damage, and damage 
circulatory and nerve tissue. 

- Copper: Although copper is an essential substance to human life, in high doses 
it can cause anemia, liver, and kidney damage, and stomach and intestinal 
irritation. People with certain illnesses such as Wilson’s disease are at 
greater risk for health effects from overexposure to copper.

- Lead: Exposure to lead can result in a wide range of biological effects 
depending on the level and duration of exposure. Various effects occur over a 
broad range of doses, with infants and children being more sensitive than 
adults. High levels of lead exposure may result in toxic biochemical effects in 
humans, which, in turn, cause problems in the synthesis of hemoglobin, effects 
on the kidneys, gastrointestinal tract, joints and reproductive system, and 
acute or chronic damage to the nervous system.

- Mercury: Mercury is a toxic substance that has no known function in human 
biochemistry or physiology and does not occur naturally in living organisms. 
Inorganic mercury poisoning is associated with tremors, gingivitis, and/or minor 
psychological changes. Natural biological processes can cause methylated forms 
of mercury to form and bioaccumulate over a million-fold and concentrate in 
living organisms, especially fish. These forms of mercury are highly toxic, 
causing neurotoxicological disorders. The main pathway for mercury to humans is 
through ingestion and not inhalation

- Zinc: Ingestion of high doses of zinc in a short period of time can lead to 
adverse health effects, such as stomach cramps, nausea, and vomiting. Long-term 
health impacts of ingesting large amounts of zinc can include anemia, nervous 
system disorders, damage to the pancreas, and lowered levels of “good” 
cholesterol.

Table 8-6. Summary of Maximum Levels Sampled for Heavy Metal Contamination

8.4.2.4 Hydrocarbon Contamination

Petroleum products such as motor fuels and lubricants enter floodwaters when 
storage tanks and vehicles overturn or are covered by floodwaters. Petroleum 
products dispersed by rapidly moving floodwaters dissolve into the water column 
and, due to the density of the petroleum fractions, float on the water surface 
and, as floodwaters recede, insoluble petroleum products floating on the water’s 
surface frequently leave a film on building materials. These petroleum products 
are sticky and can attract particulates. 

According to the Centers for Disease Control and Prevention (CDC), prolonged 
dermal contact with petroleum hydrocarbons can cause skin erythema (reddening), 
edema, and burning. The skin effects can be exacerbated by subsequent exposure 
to sunlight from the phototoxicity of trace contaminants in the oil. Human 
epidemiological studies have shown that high-dose, chronic, and occupational 
exposure to mineral oils may cause skin cancer.

Material samples were analyzed for DROs. These hydrocarbon compounds are the 
less volatile fractions of petroleum and, therefore, are less likely to have 
evaporated during the course of the 4 weeks that passed between the time of the 
initial flooding and the field investigation by the New Orleans Flood Team.

Of the 47 samples, 35 had enough collected material for an appropriate analysis. 
Over 95 percent of the analyzed sludge and wall material samples had quantities 
of DROs that exceeded the method detection limit of 18,000 µg/kg of 
hydrocarbons. As shown in Table 8-7, the sample levels ranged from 18,000 to 
3,100,000 µg/kg. The highest concentrations were found in wallpaper and wall 
material samples above the water line. 

[Begin Table]
Table 8-7. Hydrocarbon Contamination – Diesel Range Organics (µg/kg) 

Legend
White: Values are BMDL or less than 10% of the mean value.
Yellow: Values are greater than minimal but less than 50% of the mean value.
Orange: Values are greater than 50% but less than 250% of the mean value.
Red: Values are greater than 250% of the mean value.

Building: Residence at Elysian Fields
Range of Values: Maximum
Wet Sludge: 85,000 yellow
Dry Sludge: 760,000 orange
Wall Materials Below Water Line: 150,000 yellow
Wall Materials Above Water Line: 650,000 orange
Mean (Average) Value**: 454,143 white
Range of Values: Minimum
Wet Sludge: 85,000 yellow 
Dry Sludge: 760,000 orange 
Wall Materials Below Water Line: 18,000 white
Wall Materials Above Water Line: 77,000 yellow 
Mean (Average) Value**: 454,143 white
Range of Values: Average 
Wet Sludge: 85,000 yellow
Dry Sludge: 760,000 orange 
Wall Materials Below Water Line: 69,333 yellow
Wall Materials Above Water Line: 270,333 orange 
Mean (Average) Value**: 454,143 white 

Building: Residence at General Diaz Street
Range of Values: Maximum
Wet Sludge: 130,000 yellow
Dry Sludge: No Sample
Wall Materials Below Water Line: 110,000 yellow 
Wall Materials Above Water Line: 1,200,000 red
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: 130,000 yellow 
Dry Sludge: No Sample
Wall Materials Below Water Line: 110,000 yellow 
Wall Materials Above Water Line: 1,200,000 red 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: 130,000 yellow 
Dry Sludge: No Sample 
Wall Materials Below Water Line: 110,000 yellow 
Wall Materials Above Water Line: 1,200,000 red 
Mean (Average) Value**: 454,143 white 

Building: Residence at Memphis Street
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: ISFA*
Wall Materials Below Water Line: 230,000 orange
Wall Materials Above Water Line: 210,000 yellow
Mean (Average) Value**: 454,143 white
Range of Values: Minimum
Wet Sludge: No Sample 
Dry Sludge: ISFA
Wall Materials Below Water Line: ISFA 
Wall Materials Above Water Line: 210,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample 
Dry Sludge: ISFA 
Wall Materials Below Water Line: 230,000 orange 
Wall Materials Above Water Line: 210,000 yellow 
Mean (Average) Value**: 454,143 white 

Building: Residence at Savoie Court
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: ISFA
Wall Materials Below Water Line: 270,000 orange 
Wall Materials Above Water Line: 360,000 orange 
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 82,000 yellow 
Wall Materials Above Water Line: 360,000 orange 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 184,000 yellow 
Wall Materials Above Water Line: 360,000 orange 
Mean (Average) Value**: 454,143 white 
 
Building: Residence at Munster Boulevard
Range of Values: Maximum
Wet Sludge: 69,000 yellow 
Dry Sludge: 520,000 orange 
Wall Materials Below Water Line: 170,000 yellow 
Wall Materials Above Water Line: No Sample
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: 69,000 yellow 
Dry Sludge: 520,000 orange 
Wall Materials Below Water Line: 170,000 yellow 
Wall Materials Above Water Line: No Sample
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: 69,000 yellow 
Dry Sludge: 520,000 orange 
Wall Materials Below Water Line: 170,000 yellow 
Wall Materials Above Water Line: No Sample
Mean (Average) Value**: 454,143 white 

Building: Residence at Cleary Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: ISFA
Wall Materials Below Water Line: 450,000 orange 
Wall Materials Above Water Line: 200,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 190,000 yellow 
Wall Materials Above Water Line: 120,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 320,000 orange 
Wall Materials Above Water Line: 150,000 yellow 
Mean (Average) Value**: 454,143 white 
 
Building: Residence at Octavia Street
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 990,000 orange 
Wall Materials Above Water Line: 3,100,000 red
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: No Sample 
Dry Sludge: ISFA 
Wall Materials Below Water Line: 990,000 orange 
Wall Materials Above Water Line: 980,000 orange 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample 
Dry Sludge: ISFA 
Wall Materials Below Water Line: 990,000 orange 
Wall Materials Above Water Line: 1,860,000 red 
Mean (Average) Value**: 454,143 white 

Building: Fire station at Louisiana Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: No Sample
Wall Materials Below Water Line: 580,000 orange 
Wall Materials Above Water Line: 220,000 yellow
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: No Sample 
Wall Materials Below Water Line: 580,000 orange 
Wall Materials Above Water Line: 220,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: No Sample 
Wall Materials Below Water Line: 580,000 orange 
Wall Materials Above Water Line: 220,000 yellow 
Mean (Average) Value**: 454,143 white 
 
Building: Fire station at South Carrollton Avenue
Range of Values: Maximum
Wet Sludge: No Sample
Dry Sludge: ISFA
Wall Materials Below Water Line: 130,000 yellow 
Wall Materials Above Water Line: 190,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Minimum
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 130,000 yellow 
Wall Materials Above Water Line: 190,000 yellow 
Mean (Average) Value**: 454,143 white 
Range of Values: Average
Wet Sludge: No Sample
Dry Sludge: ISFA 
Wall Materials Below Water Line: 130,000 yellow 
Wall Materials Above Water Line: 190,000 yellow 
Mean (Average) Value**: 454,143 white 

* iSFA = insufficient sample for analysis
** The Mean (Average) Value was the statistical average value computed for the 
35 DRO sample results

Statistical Sample Values
BMDL: 18,000
10% Mean: 45,414
50% Mean: 227,071
Mean: 454,143
250% Mean 1,135,357
Maximum: 3,100,000

 [End Table]

8.4.2.5 Pesticide Contamination

Historically, the New Orleans area has suffered damages to many of its buildings 
from termites. In the past, termite treatment involved applying a barrier of 
organochlorine pesticides (e.g., chlordane, dichloro-diphenyl-trichloroethane 
(DDT), dieldrin, and heptachlor) into the soil surrounding the building and to 
the wooden sills of houses. After drilling holes, the insecticide was diluted 
with water to form a solution and applied to the soil. Depending on the size of 
the property, it was not unusual to apply 100 gallons or more of the insecticide 
solution. 

Floodwaters transport both water-soluble and non-water-soluble chemicals. In the 
case of pesticides, many of the organophosphates that are used today are water 
soluble, which means that any residue in the soil impacted by the flooding would 
tend to be diluted by the floodwaters. By contrast, older pesticides, such as 
DDT and chlordane, were generally organochlorine compounds that are not as water 
soluble as the newer materials, because they were diluted by oils rather than 
water. This chemical composition allowed the now banned pesticides to have a 
lon­ger impact in protecting buildings from termites and other insects, with 
many such compounds residing in soil for over 20 years without significant loss 
in concentration. However, this residual effect also allowed the chemicals to 
build up in the environment, which was a significant rationale for eliminating 
their use in the United States approximately 18 years ago.

Pesticide residues, such as those found in the building materials of older 
structures, can cause skin rashes from dermal contact. Inhalation of such 
residue in demolition dust can lead to a host of problems as many of the 
substances are neurotoxins. Another significant risk of exposure can occur when 
individuals involved in the gutting and decontamination fail to wash their hands 
before eating, since hand to mouth activities have been demonstrated as the 
source of ingested pesticides. When ingested or absorbed through the skin, 
organochlorine pesticides affect the nervous system, the digestive system, and 
the liver in people and animals.

The USEPA floodwater sampling data from New Orleans confirmed the supposition 
that the newer organophosphate pesticides were diluted by the large volumes of 
floodwater while the organocholorine pesticides were not. These findings, along 
with the documented heavy historic use of organocholorine pesticides to control 
termites in the New Orleans area, led to the concern by the New Orleans Flood 
Team that these contaminants may have been disturbed during the flooding and 
carried into buildings. Therefore, 5 of the sludge and 30 of the building 
ma­terial samples collected were screened for organochlorine type pesticides 
(these samples had enough remaining volume to be analyzed after the other tests 
had been completed). A summary of the highest levels of pesticides evaluated 
during the analysis of the samples collected from the New Orleans area is shown 
in Table 8-8.
 
[Begin Table]
Table 8-8. Summary of Maximum Levels Sampled for Pesticides (µg/kg)

Pesticide
 Chlordane
 alpha-Chlordane
 gamma-Chlordane
 DDT
 Dieldrin
 Heptachlor
 
Building
 Age of Building
 Mean (Average) Value**
 890
 104
 146
 14.2
 14.4
 5.5
 
Residence at Elysian Fields
 1940s
 Wet Sludge
 280
 19
 11
 7
 BMDL
 13
 
Dry Sludge
 410
 30
 14
 9
 BMDL
 16
 
Wall Materials Below Water Line
 280
 19
 16
 6
 BMDL
 16
 
Wall Materials Above Water Line
 810
 73
 87
 78
 14
 41
 
Residence at General Diaz Street
 1930s
 Wet Sludge
 190
 18
 39
 40
 19
 4
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 160
 13
 10
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 2,100
 130
 350
 35
 150
 45
 
Residence at Memphis Street
 1990s
 Wet Sludge
 No Sample
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 
Residence at Savoie Court
 1960s
 Wet Sludge
 No Sample
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 130
 18
 20
 BMDL
 10
 BMDL
 
Wall Materials Above Water Line
 1,400
 170
 220
 BMDL
 260
 BMDL
 
Residence at Munster Boulevard
 1940s
 Wet Sludge
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 
Dry Sludge
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 
Wall Materials Below Water Line
 130
 21
 24
 6
 BMDL
 BMDL
 
Wall Materials Above Water Line
 No Sample
 
Residence at Cleary Avenue
 1990s
 Wet Sludge
 No Sample
 
Dry Sludge
 Analysis voided due to insufficient sample quantity
 
Wall Materials Below Water Line
 37
 5.0
 5.5
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 26
 BMDL
 BMDL
 BMDL
 BMDL
 BMDL
 
Residence at Octavia Street
 Older
 Wet Sludge
 No Sample
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 2,200
 220
 380
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 1,600
 200
 240
 250
 BMDL
 BMDL
 
Fire station at Louisiana Avenue
 Older 
 Wet Sludge
 No Sample
 
Dry Sludge
 Analysis voided due to insufficient sample quantity
 
Wall Materials Below Water Line
 17,000
 2,100
 2,900
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 1,400
 180
 260
 BMDL
 BMDL
 BMDL
 
Fire station at South Carrollton Avenue
 1954
 Wet Sludge
 No Sample
 
Dry Sludge
 Analysis voided due to insufficient sample quantity
 
Wall Materials Below Water Line
 100
 15
 18
 BMDL
 BMDL
 BMDL
 
Wall Materials Above Water Line
 130
 13
 11
 BMDL
 BMDL
 BMDL
 
* BMDL = Below minimum detectable limit. For pesticide sample results, BMDL 
values are summarized below:
 
Pesticide
 Chlordane
 alpha-Chlordane
 gamma-Chlordane
 DDT
 Dieldrin
 Heptachlor
 
Below Method Detection Limit is less than (µg/kg)
 17
 3.3
 3.3
 3.3
 3.3
 3.3
 
** The Mean (Average) Value was the statistical average value computed for the 
35 pesticide samples results. When computing the average value, samples with 
BMDL values were assumed to have a value equal to 1/2 the BMDL de­tection limit 
in accordance with USEPA standard practice.
 
Values are BMDL or less than 10% of the mean value.
 
Values are greater than minimal but less than 50% of themean value.
 
Values are greater than 50% but less than 250% of the mean value.
 
Values are greater than 250% of the mean value.
[End Table]

The pesticide results provided in Table 8-8 indicate that six organochlorine 
pesticides were found in significant quantities: chlordane, alpha-chlordane, 
gamma-chlordane, DDT, dieldrin, and heptachlor. Other pesticides detected in 
much smaller quantities and not listed in Table 8-8 include beta-benzene 
hexachloride (BHC), gamma-BHC, dichloro-diphenyl-dichloroethane (DDD), dichloro-
diphenyl-dichloroethylene (DDE), endosulfan II, endosulfan sulfate, endrin 
ketone, and methoxychlorindicate. Table 8-8 indicates that the highest 
concentrations of or­ganochlorine pesticides were typically found in wall 
materials rather than sludge materials. For example, the highest level of 
chlordane identified in the sludge samples was 410 µg/kg, while the highest 
level of chlordane identified in the wall material samples was 17,000 µg/kg. In 
fact, two of the five sludge samples analyzed for organochlorine pesticides were 
below the method detection limit. 

The pesticide contamination results were compared to the estimated age of each 
building (estimated based on its appearance, construction materials, 
architectural components, and other details). As shown in Table 8-8, older 
buildings, which were more likely to have been protected with chlordane and 
other organocholorine pesticides, had higher levels than newer buildings (post-
chlordane). Presumably, the floodwaters released some of the pesticide residues 
from soils near the buildings. Once the pesticide was in suspension, it would be 
diluted by the water and transported onto flooded materials.

8.4.2.6 PCB Contamination

Although PCB contamination was anticipated based on the number of transformers 
and other electrical devices that were submerged or knocked down during the 
hurricane, no PCBs were detected in the 35 samples that were analyzed for the 
substance.

No PCBs were detected in any of the 35 samples analyzed for the substance. These 
findings were not unusual since the use of PCBs was banned by the USEPA in  979. 
Also, the findings were consistent with the results of sampling conducted by the 
USEPA in the New Orleans area following Hurricanes Katrina and Rita. 


Figure 8-1. Residential buildings and critical and essential facilities visited 
by the New Orleans Flood Team. (Due to the map scale, some sites are not 
included on this map.)


Figure 8-2. Map of estimated flood depths in New Orleans Source: FEMA

Figure 8-3. Residential building constructed approximately 1 foot above the BFE 
in accordance with current codes. Note flood depths were even with the top of 
the garage door, or about 3-5 feet above the first floor (red line).

Figure 8-4. Comparison of building techniques in New Orleans. The older 
residence on the upper left has the first finished floor constructed several 
feet above grade. The newer residence on the lower right is constructed with a 
slab-on-grade foundation.



Figure 8-5. The Industrial Canal levee breach in New Orleans Source: LSU 
Hurricane Center


Figure 8-6. Structural damage to residential buildings (circle) in New Orleans 
located immediately behind the site of 17th Street Canal levee breach (arrow)

Figure 8-7. Settlement cracks in upper floor wall of New Orleans residence due 
to subsidence/differential settlement of underlying foundation soils during 
long-duration flooding 

Figure 8-8. Exposed wall studs and sheathing boards in 74-year-old New Orleans 
residential building, showing no significant deterioration from long-duration 
flooding

Figure 8-9. Exposed wall studs and sheathing boards in 2-year-old New Orleans 
residential building, showing no significant deterioration from long-duration 
flooding.

Figure 8-10.Typical interior flood damage to residential building in New 
Orleans, showing extensive mold growth (circle)

Figure 8-11. Typical interior flood damage to residential building in New 
Orleans, showing light mold growth (compare to Figure 8-10)

Figure 8-12. Damage to garage bay doors at fire station in New Orleans. The door 
on the right was pushed in by flooding; the door on the left appears to have 
been pulled open from the outside by looters.

Figure 8-13. Flooded emergency generator at hospital in New Orleans (note flood 
line in red)


Capillary action. Capillary action, commonly referred to as “wicking,” is the 
process by which water molecules adhere to surfaces and climb upward through 
ma­terials against gravity.

Water vapor migration. Water vapor migration through the interior of a building 
is invisible and often overlooked. Water vapor affects materials such as wood 
and paper, which increase or decrease in size (i.e., swell or shrink) based on 
their mois­ture content.

Solvent action. Water is a powerful and effective solvent and can dissolve some 
paper products such as drywall (gypsum board) paper.

Corrosion. Metals of differing composition in contact with one another in the 
presence of water or water vapor are vulnerable to corrosion. Corrosion is 
predictable. For example, when copper electrical wire con­tacts a steel screw, 
the more chemically active metal corrodes. Corrosion increases as the salinity 
of the water increases.

Figure 8-14. Kitchen cabinet doors above the flood level were damaged from the 
excessive moisture in the house from long-duration flooding.

Specific Humidity and Drying Flooded Buildings 

After hurricanes, residents are generally urged to open their buildings to dry 
out building materials as soon as possible. Relative humidity (which changes 
accord­ing to air temperature) has been used in the past to measure progress and 
make decisions regarding post-flood building drying. However, relative humidity 
is an inaccurate measurement and should be abandoned in favor of using specific 
(or absolute) humidity (which is a measure of the actual moisture content, 
regardless of temperature). When determining the extent of drying in a building 
following a flood, temperature and relative humidity readings should be taken 
inside and outside of the building in order to determine the specific humidity 
read­ings inside and outside the building. These readings can be obtained by 
using tables or charts that convert temperature and relative humidity to 
specific humidity, or by means of special equipment such as a commercially-
available moisture meter.

When the specific humidity inside the building is greater than the specific 
humidity outside, natural processes such as open­ing the windows and doors can 
be used to facilitate drying inside the building. By contrast, when the specific 
humidity inside the building is less than the specific humidi­ty outside, 
artificial means such as fans or drying equipment should be used to facilitate 
drying inside the building. it is important to note that the comparative 
specific humidity readings outside and inside the building should be taken at 
about the same time, and that the comparative readings and the moisture 
reduction methods employed in a given building are subject to change during the 
course of the drying process.

Figure 8-15. Flood residue and buckled floor observed on General Diaz Street. A 
sample of the flood residue was collected for analysis. 

Figure 8-16. Samples were collected from wall materials both above and below the 
waterline as shown on this wall of a house on Memphis Street. Where practical, 
samples were collected from surfaces that were already substantially damaged or 
scheduled for tear-out.

Table 8-3. Highlights of the Biological and Chemical Contaminant Sampling 
Results (continued)

Table 8-3. Highlights of the Biological and Chemical Contaminant Sampling 
Results (continued)

Figure 8-17. Bacteria levels were frequently found to be significantly lower in 
areas with rampant fungal growth. This pattern held true at the residence on 
Savoie Court, where fungal levels were extensive on the dresser and carpet near 
the door frame while the bacteria levels were negligible at these same 
locations.

Table 8-5. Summary of Fungal Sampling Data (continued)

Building Site
 Sample Location
 Indicator Organisms
 Common Organisms
 Target Organisms
 Hyphae
 



Figure 8-18. Prolific mold growth was seen on porous contents in most inspected 
buildings.

Figure 8-19. The mold growth on the walls was generally much more vigorous above 
the floodwater level than below it. Sediments, heavy metal contamination, and 
oil film residue, as well as material moisture content and lack of exposure to 
air during flooding, may contribute to minimizing the fungal growth on the 
saturated wall materials.

Figure 8-20. In many buildings, the mold growth above the  waterline appears to 
have been fueled by condensation of moisture in addition to water "wicking." The 
upper cabinets and kitchen ceiling in the building on General Diaz Street were 
well above the floodwater line, yet showed extensive fungal growth.

Figure 8-21. On Savoie Court, fungal growth was observed up to the ceiling on 
some walls, despite the fact that floodwaters only reached up 18-24 inches. This 
wall showed thick mold growth both above and below the high water mark.

Building
 Element
 Antimony
 Arsenic
 Beryllium
 Cadmium
 Chromium
 Copper
 Lead
 Mercury
 Nickel
 Selenium
 Silver
 Thallium
 Zinc
 
Mean (Average) Value**
 12,337
 6,787
 226
 3,491
 9,362
 31,263
 62,690
 1,190
 14,340
 1,109
 157
 169
 1,373,191
 
Residence at Elysian Fields
 Wet Sludge
 650
 17,000
 850
 42,000
 25,000
 81,000
 130,000
 260
 130,000
 14,000
 BMDL
 350
 4,800,000
 
Dry Sludge
 BMDL
 9,700
 1,200
 2,400
 33,000
 64,000
 170,000
 63
 26,000
 BMDL
 1,200
 BMDL
 750,000
 
Wall Materials Below Water Line
 650
 17,000
 850
 42,000
 25,000
 81,000
 130,000
 260
 14,000
 1,800
 350
 BMDL
 4,800,000
 
Wall Materials Above Water Line
 BMDL
 1,900
 120
 160
 4,400
 4,800
 390
 89
 26,000
 1,800
 BMDL
 BMDL
 11,000
 
Residence at General Diaz Street
 Wet Sludge
 BMDL
 23,000
 430
 5,700
 14,000
 62,000
 120,000
 BMDL
 130,000
 BMDL
 320
 BMDL
 2,300,000
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 BMDL
 560
 BMDL
 BMDL
 1,400
 610
 2,500
 ISFA
 8,100
 BMDL
 BMDL
 BMDL
 23,000
 
Wall Materials Above Water Line
 300
 1,100
 1,400
 BMDL
 1,400
 540
 750
 BMDL
 8,200
 BMDL
 BMDL
 BMDL
 4,000
 
Residence at Memphis Street
 Wet Sludge
 No Sample
 
Dry Sludge
 2,300
 60,000
 760
 10,000
 36,000
 220,000
 240,000
 140
 18,000
 3,100
 870
 340
 32,000,000
 
Wall Materials Below Water Line
 370
 520
 BMDL
 76
 3,300
 820
 780
 120
 7,200
 1,300
 BMDL
 BMDL
 28,000
 
Wall Materials Above Water Line
 BMDL
 1,200
 150
 220
 4,800
 1,400
 780
 180
 13,000
 3,300
 BMDL
 BMDL
 19,000
 
Residence at Savoie Court
 Wet Sludge
 No Sample
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 BMDL
 2,500
 150
 BMDL
 3,800
 3,200
 1,000
 70
 13,000
 BMDL
 160
 BMDL
 26,000
 
Wall Materials Above Water Line
 BMDL
 3,000
 110
 700
 12,000
 6,800
 4,000
 BMDL
 6,200
 BMDL
 BMDL
 BMDL
 300,000
 
Residence at Munster Boule vard
 Wet Sludge
 BMDL
 3,200
 320
 400
 5,600
 10,000
 12,000
 BMDL
 8,700
 590
 BMDL
 BMDL
 62,000
 
Dry Sludge
 BMDL
 8,200
 1,100
 840
 16,000
 30,000
 35,000
 BMDL
 26,000
 1,800
 330
 BMDL
 170,000
 
Wall Materials Below Water Line
 BMDL
 1,500
 BMDL
 BMDL
 910
 590
 1,300
 120
 5,800
 BMDL
 BMDL
 BMDL
 18,000
 
Wall Materials Above Water Line
 No Sample
 
Residence at Cleary Avenue
 Wet Sludge
 No Sample
 
Dry Sludge
 Analysis voided due to insufficient sample quantity
 
Wall Materials Below Water Line
 BMDL
 1,200
 270
 140
 13,000
 10,000
 47,000
 83
 8,400
 2,000
 100
 BMDL
 31,000 
 
Wall Materials Above Water Line
 BMDL
 2,400
 BMDL
 150
 1,800
 12,000
 2,000
 160
 8,700
 2,100
 110
 BMDL
 12,000
 
Residence at Octavia Street
 Wet Sludge
 No Sample
 
Dry Sludge
 No Sample
 
Wall Materials Below Water Line
 BMDL
 290
 BMDL
 54
 5,600
 1,300
 25,000
 10,000
 BMDL
 BMDL
 BMDL
 BMDL
 74,000
 
Wall Materials Above Water Line
 BMDL
 1,400
 180
 670
 16,000
 8,800
 34,000
 32,000
 7,300
 BMDL
 100
 BMDL
 210,000
 
Fire station at Louisiana Avenue
 Wet Sludge
 No Sample
 
Dry Sludge
 11,000
 45,000
 110
 22,000
 24,000
 200,000
 1,300,000
 470
 13,000
 1,000
 890
 330
 5,400,000
 
Wall Materials Below Water Line
 470
 2,700
 BMDL
 200
 2,600
 4,200
 7,400
 BMDL
 8,300
 BMDL
 BMDL
 BMDL
 180,000
 
Wall Materials Above Water Line
 BMDL
 2,100
 110
 53
 1,900
 1,300
 2,300
 BMDL
 7,700
 800
 BMDL
 430
 9,800
 
Fire station at South Carroll­ton Avenue
 Wet Sludge
 No Sample
 
Dry Sludge
 330,000
 81,000
 310
 24,000
 100,000
 490,000
 390,000
 1,600
 44,000
 BMDL
 740
 BMDL
 8,500,000
 
Wall Materials Below Water Line
 BMDL
 730
 140
 60
 3,300
 1,600
 2,400
 93
 7,300
 BMDL
 BMDL
 BMDL
 9,800
 
Wall Materials Above Water Line
 BMDL
 1,000
 BMDL
 BMDL
 2,500
 930
 3,600
 65
 8,400
 BMDL
 BMDL
 BMDL
 6,000
 
* BMDL = Below minimum detectable limit
 
** the Mean (Average) Value was the statistical average value computed for the 
44 heavy metal sample results. When computing the average value, samples with 
BMDL values were assumed to have a value equal to 1/2 the BMDL detection limit 
in accordance with uSEPA standard practice.
 

Values are BMDL or less than 10% of the mean value.
 
Values are greater than minimal but less tha 50% of themean value.
 
Values are greaten than 50% but less than 250% of the mean value.
 
Values are greater than 250% of the mean value.
 



Table 8-6. Summary of Maximum Levels Sampled for Heavy
 Metal Contamination (µg/kg) 
 



Heavy Metal
 Antimony
 Arsenic
 Beryllium
 Cadmium
 Chromium
 Copper
 Lead
 Mercury
 Nickel
 Selenium
 Silver
 Thallium
 Zinc
 
Below Method Detection Limit is less than (µg/kg)
 300
 100
 100
 50
 300
 300
 200
 60
 300
 500
 100
 300
 300
 



Table 8-6. Summary of Maximum Levels Sampled for Heavy
 Metal Contamination (µg/kg) (continued)
 



Building
 Element
 Antimony
 Arsenic
 Beryllium
 Cadmium
 Chromium
 Copper
 Lead
 Mercury
 Nickel
 Selenium
 Silver
 Thallium
 Zinc
 
Mean (Average) Value**
 12,337
 6,787
 226
 3,491
 9,362
 31,263
 62,690
 1,190
 14,340
 1,109
 157
 169
 1,373,191
 



Statistical Sample Values
 
BMDL
 18,000
 
10% Mean
 45,414
 
50% Mean 
 227,071
 
Mean
 454,143
 
250% Mean
 1,135,357
 
Maximum
 3,100,000
 



Table 8-8. Summary of Maximum Levels Sampled for
 Pesticides (µg/kg) (continued)

Pesticide
 Chlordane
 alpha-Chlordane
 gamma-Chlordane
 DDT
 Dieldrin
 Heptachlor
 
Building
 Age of Building
 Mean (Average) Value**
 890
 104
 146
 14.2
 14.4
 5.5