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Summary of Water Testing: Hurricanes Katrina and Rita

Test Results

Environmental Assessment Summary for Areas of Jefferson, Orleans, St. Bernard, and Plaquemines Parishes Flooded as a Result of Hurricane Katrina (December 6, 2005)

EPA has tested two distinct types of water in the aftermath of Hurricanes Katrina and Rita: flood water and surface water bodies (for example, the Gulf of Mexico). This page presents summaries for both types of testing.

Index for other types of test results

Surface Water Testing Summary

The U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), the Food and Drug Administration (FDA), and the U.S. Geological Survey (USGS) are coordinating an environmental impact assessment of Hurricanes Katrina and Rita in coastal waters throughout the affected region. By integrating response activities conducted aboard the EPA’s OSV Bold, NOAA’s R/V Nancy Foster, FDA small boat teams and numerous field activities in the shallow nearshore and wetland environments, this effort will characterize the magnitude and extent of coastal contamination and ecological effects resulting from these unprecedented storms.

Leg 1: Mouth of the Mississippi River, September 27 - October 2, 2005 Leg 2: Mississippi Sound, October 10 - October 13, 2005
Leg 3: Lake Ponchartrain, October 10-October 14, 2005

Leg 1: Mouth of the Mississippi River, September 27 - October 2, 2005

Summary

Test results from Gulf of Mexico sampling indicate that at most, relatively low levels of fecal contamination were present after the hurricane. The Clostridium perfringens tests show that the levels were low to undetectable. Previously released enterococcus tests show that at the time of sampling the water was appropriate for any kind of recreational use--including swimming. Water samples were collected by the OSV Bold in the Gulf from Sept. 27 through Oct. 2, 2005 at monitoring stations in the river channels and nearshore waters surrounding the Mississippi Delta. The agency monitored 20 areas to determine whether fecal pollution from flooded communities had spread into these waters.

Clostridium perfringens is a bacterium, found in the intestinal tract of both humans and animals. It enters the environment through feces. There are no EPA health-based ambient water quality criteria for C. perfringens. Therefore, there is no approved analytical method for assessing water quality using this bacterium. However, some scientists recommend using C. perfringens spores as a tracer of fecal pollution because its presence is a good indicator of recent or past fecal contamination in water and spores survive well beyond the typical life-span of other fecal bacteria.

EPA previously released results for enterococcus, which was detected at four of 20 stations from 10 to 53.1 bacteria colonies per 100 milliliters. These results indicate that the water is suitable for any kind of recreational use. This level is below the most conservative marine water criteria of 104 bacteria per 100 milliliters.

It is difficult, due to absence of previously analyzed data, to determine the source of the C. perfringens and enterococci. They could have been present prior to the hurricane. Bacteria were not routinely analyzed prior to Hurricane Katrina.

While all of these results are encouraging for recreational uses, this data should not be used to assess the safety of consuming raw or undercooked molluscan shellfish--such as oysters-- because accidental ingestion of water presents different risks than eating raw or undercooked shellfish.

Enterococci results

This preliminary report summarizes to-date results obtained for the first leg of the assessment aboard the EPA OSV Bold. During this leg, samples were collected from September 27 through October 2, 2005 from stations in the near eastern region of the Mississippi River delta, into the Mississippi River channels, and the near western region of the Mississippi River delta.

Four samples tested positive for enterococci. River channel stations 10 and 20 showed the highest counts. These samples had low salinity and were run undiluted. Throughout the cruise, several Enterolert tests run with a negative control strain in sterile water did not give any positive wells.

In evaluating the enterococci results, EPA uses a single sample maximum (SSM) based on the frequency of exposure and found within the water quality criteria recommendations developed by EPA in 1986 (EPA440/5-84-002). EPA compares the result with both the SSM for a designated beach area, which represents the greatest amount of full body contact exposure, and the SSM for infrequently used full body contact recreation, which represents the lowest amount of exposure. Based on the most recent sampling, EPA has found that enterococci SSM at Stations 1 to 20 were below a level which is typically used to characterize the designated beach areas. The waters in these areas are suitable for all primary contact recreation, which includes swimming.

These results should not be used to assess whether raw or undercooked molluscan shellfish (such as oysters) should be consumed. This is because the water quality criteria recommendations against which the monitoring data are compared are different between recreational (enterococcus) and shellfish (fecal coliform) uses, and because accidental ingestion of water presents different risks than eating raw or undercooked shellfish. Nevertheless, these results are valuable for identifying trends in the level and extent of contamination. The state molluscan shellfish program can use these results in planning when to do fecal coliform monitoring as a basis for deciding whether to reopen harvesting areas, as provided under state regulation and the National Shellfish Sanitation Program.

Sample Collection Date Lat DD (N) Long DD (W) Station Number Colonies/100 mL
09/27/05 29.1506 -88.9643 1 <1
09/27/05 29.1769 -88.8117 2 <1
09/27/05 29.1667 -88.5500 3 <1
09/28/05 29.0939 -89.0164 4 <1
09/28/05 29.0257 -88.9056 5 <1
09/28/05 28.9560 -88.8071 6 <1
09/28/05 28.9575 -89.1190 7 <1
09/28/05 28.8659 -89.1155 8 <1
09/28/05 28.7545 -89.1038 9 1
09/29/05 29.0490 -89.3151 10 53.1
09/29/05 28.9636 -89.3877 11 <1
09/29/05 28.9058 -89.4595 12 1
09/29/05 28.8707 -89.4693 13 <1
09/30/05 29.2892 -89.7520 14 1
09/30/05 29.0766 -89.7538 15 <1
10/01/05 29.0595 -90.1985 16 <1
10/01/05 28.9955 -90.0840 17 <1
10/01/05 29.0230 -90.4696 18 <1
10/01/05 28.8601 -90.4607 19 <1
09/29/05 29.1829 -89.2640 20 28.8

Clostridium perfringens results

Results of Microbiological Monitoring Around the Mississippi River Delta Aboard OSV Bold
September 27 to October 2, 2005

Background

The EPA is leading an effort to ascertain possible effects from Hurricane Katrina on waters off Louisiana and in the Mississippi Sound. One concern being addressed is whether or not fecal pollution from New Orleans and other inundated areas has spread into these coastal waters. Microbiological assays for fecal pollution have therefore been incorporated into the assessment. This preliminary report summarizes to date results obtained for the first leg of the assessment aboard the EPA OSV Bold. During this leg, samples were collected from September 27 through October 2, 2005 from stations in the near eastern region of the Mississippi River delta, into the Mississippi River channels, and the near western region of the Mississippi River delta.

What is Clostridium perfringens?

Clostridium perfringens is a bacterium, found in the intestinal track of both humans and animals, which acts as a catalyst in the digestive process. This bacterium is introduced into the environment through feces. It has a unique set of characteristics that distinguishes it from other common fecal indicators such as coliforms and makes it a useful fecal tracer for scientists. C. perfringens typically grow in the absence of air and form protective spores, which allow it to live well beyond the typical life-span of coliforms. Some scientists recommend using C. perfringens as a tracer of fecal pollution because its presence is a good indicator of recent or past fecal contamination in water.

Clostridium perfringens results from the samples collected on the EPA OSV Bold

The sampling revealed that the levels of C. perfringens detected were low to almost undetectable. These results indicate that severe fecal pollution did not occur in the water sampled. The low levels of C. perfringens that were detected correspond to the higher enterococci sample counts found in the Gulf of Mexico at the same sampling locations. There were also several low level positive sample counts of C. perfringens where enterococci indicator organisms were not detected.

It is impossible to determine when the C. perfringens and enterococci contamination occurred or if they originated from animal or human fecal sources. It is possible that these bacteria were present in the water environment prior to the hurricane, but this cannot be verified because these bacteria were not routinely analyzed prior to Hurricane Katrina.

It is important to note that currently there are no EPA health-based ambient water quality criteria for C. perfringens, or approved analytical method for assessing the occurrence levels of this bacterium for water assessments. A connection between the occurrence or levels of this bacterium in swimming waters and gastrointestinal illness has not been established. At this time, EPA cannot make a scientifically based determination of the risk of gastrointestinal disease risks from the presence of C. perfringens in these Gulf water samples.

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Leg 2: Mississippi Sound, October 10 - October 13, 2005

Background

The second outing aboard the OSV Bold originated from Gulfport, Mississippi, during October 10-13, 2005. Smaller boats collected water samples daily from stations designated Kat-0001-1 to Kat-0030-1. Stations were located throughout the Mississippi Sound. Samples were collected from Dauphin Island, AL, to Lake Borgne, LA. For quality control, duplicate samples were taken at various stations. During this tenure, samples collected from Dauphin Island, AL, were transported by vehicle to the OSV Bold within 6 hrs.

Samples and Analyses

Surface waters (0.5-1 meter) were collected in Niskin bottles for microbiological monitoring to assess fecal contamination or presence. Bottles utilized for enterococci were sterile. GED is conducting assays for microbiological assessment using Enterolert Test Kit (IDEXX Laboratories) to detect enterococci. These organisms and assays were selected for ease of use aboard ship, for differing specificities and for persistence of the indicator for varying lengths of time.

The Enterolert kit for enterococci was completed following a 24 hr incubation for each set of samples during the cruise(s). All samples were stored at 4 o C during holding and transport.

The Enterolert Test Kit is capable of detecting one enterococci colony forming unit (CFU) in a 100 ml sample. Seawater samples need to be diluted 1:10 for the tests. Enterococci metabolize the substrate to a fluorescent product which, after 24 hours of incubation at 41.5 o C, is detected with a UV lamp. The 51-well Enterolert Quanti Tray was selected for the enterococci assessment. This format provides a Most Probable Number (MPN) of enterococci in a 100 ml sample between 1 and 200, depending upon the number of positive wells.

Table 1: Enterolert results for the presence of enterococci from the 2nd cruise leg in Mississippi Sound.

Sample Date Lat DD (N) Long DD (W) KAT Station number Number of positive wells MPN (CFU per 100 ml) Dilution factor MPN (with dilution factor)
10/11/05
30.28890
-88.31218
1
0
<1
10
<10
10/12/05
30.03640
89.53053
2
0
<1
10
<10
10/12/05
29.99930
-89.69680
3
0
<1
10
<10
10/10/05
30.24305
-88.91033
4
0
<1
10
<10
10/12/05
30.00253
-89.61468
5
0
<1
10
<10
10/11/05
30.27273
-88.61060
6
0
<1
10
<10
10/11/05
30.12970
-89.33755
7
0
<1
10
<10
10/10/05
30.30300
-89.12585
8
1
1
10
10
10/10/05
30.30300
-89.12585
8 dup
0
<1
10
<10
10/11/05
30.21087
-88.40647
9
0
<1
10
<10
10/10/05
30.27368
-89.28715
10
0
<1
10
<10
10/10/05
30.15418
-89.28512
11
1
1
10
10
10/10/05
30.33940
-88.95940
12
0
<1
10
<10
10/12/05
29.98665
-89.80743
13
0
<1
10
<10
10/11/05
30.27548
-88.72187
14
0
<1
10
<10
10/11/05
30.11127
-89.44350
15
0
<1
10
<10
10/11/05
30.32292
-88.75270
16
0
<1
10
<10
10/11/05
30.33732
-88.29755
17
0
<1
10
<10
10/11/05
30.23360
-89.32362
18
0
<1
10
<10
10/12/05
29.96380
-89.70112
19
0
<1
10
<10
10/10/05
30.26435
-88.87720
20
0
<1
10
<10
10/12/05
30.08735
-89.60563
21
0
<1
10
<10
10/11/05
30.33068
-88.65347
22
0
<1
10
<10
10/11/05
30.19088
-89.36315
23
0
<1
10
<10
10/10/05
30.36645
-88.98443
24
1
1
10
10
10/11/05
30.32098
-88.36473
25
0
<1
10
<10
10/12/05
30.17318
-89.56095
26
0
<1
10
<10
10/10/05
30.23578
-89.16255
27
0
<1
10
<10
10/10/05
30.25510
-88.94950
28
0
<1
10
<10
10/12/05
30.04357
-89.76833
29
0
<1
10
<10
10/12/05
30.15578
-89.62365
30
0
<1
10
<10
10/12/05
pos ctls
51
>200
1
>200
10/12/05
neg ctl 1
0
<1
1
<1
10/12/05
neg ctl 2
3
1
1
3

Positive controls were Enterococcus faecium and E faecalis. Negative control 1 was Aerococcus viridans, negative control 2 was Serratia marcescens. Enterolert trays contained 51 wells.

Conclusions

In evaluating the enterococci results, EPA uses a single sample maximum (SSM) based on the frequency of exposure and found within the water quality criteria recommendations developed by EPA in 1986 (EPA440/5-84-002). EPA compares the result with both the SSM for a designated beach area, which represents the greatest amount of full-body contact exposure, and the SSM for infrequently used full-body contact recreation, which represents the lowest amount of exposure. Based on the most recent sampling (October 10-14, 2005), EPA has found that enterococci SSM at stations 1-30 were below a level which is typically used to characterize the designated beach areas. The waters in these areas are suitable for all primary contact recreations, which includes swimming.

These results should not be used to assess whether raw or undercooked molluscan shellfish (such as oysters) should be consumed. This is because the water quality criteria recommendations against which the monitoring data are compared are different between recreational (enterococcus) and shellfish (fecal coliforms) uses, and because accidental ingestion of water presents different risks than eating raw or undercooked shellfish. Nevertheless, these results are valuable for identifying trends in the level and extent of contamination. The state molluscan shellfish program can use these results in planning when to do fecal coliform monitoring and as a basis for deciding whether to reopen harvesting areas, as provided under state regulation and the National Shellfish Sanitation Program.

Test results

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Leg 3: Lake Ponchartrain, October 10-October 14, 2005

Background

The third leg of the Post Katrina assessment involved the collection of samples from 30 sites in Lake Pontchartrain. USGS out of Lafayette and Baton Rouge, LA partnered with EPA in implementing this portion of the study. USGS performed the sample collection and analysis of microbial samples on site. All remaining samples and data were provided to EPA for laboratory analyses. For quality control, duplicate samples were taken at various stations. All microbial samples were analyzed within the 6 hour holding time of the protocol.

Samples and Analyses

Surface waters (0.5-1 meter) were collected in Niskin bottles for microbiological monitoring to assess fecal contamination or presence. All samples were collected into sterile 1.0 liter bottles. USGS conducted 2 microbial assays on each surficial water sample that was collected. Fecal Coliforms and Enterococci (EPA Method 1600) were both assayed using membrane filtration methodologies. These methodologies both rely on the culture of the targeted organism on specific media which includes an indicator color for the colonies of interest.

Table 1: Fecal Coliform results from Leg 3, Lake Pontchartrain

Sample Date Lat DD
(N)

Long DD
(W)

 KAT Station number

Fecal Coliforms
Colonies/100 ml
10/11/05 30.165817 -90.030217 LP-0001 <1
10/14/05 30.170883 -89.752317 LP-0002 <1
10/12/05 30.217483 -90.212250 LP-0003 <1
10/14/05 30.108550 -89.789700 LP-0004 <1
10/11/05 30.202467 -90.018800 LP-0005 1
10/11/05 30.202467 -90.018800 LP-0005R 1
10/12/05 30.244317 -90.258417 LP-0006 1
10/14/05 30.302133 -89.996433 LP-0007 <1
10/14/05 30.302133 -89.996433 LP-0007R <1
10/13/05 30.095750 -90.358417 LP-0008 <2
10/11/05 30.226333 -90.103150 LP-0009 <1
10/11/05 30.220950 -89.950483 LP-0010 2
10/12/05 30.139667 -90.219783 LP-0011 1
10/13/05 30.108433 -90.252317 LP-0012 12
10/13/05 30.112967 -90.143683 LP-0013 <2
10/12/05 30.332167 -90.183833 LP-0014 1
10/14/05 30.170733 -89.704017 LP-0015 <1
10/13/05 30.080833 -90.301133 LP-0016 6
10/13/05 30.080833 -90.301133 LP-0016R 4
10/11/05 30.115500 -89.941667 LP-0017 2
10/14/05 30.269250 -90.029367 LP-0018 <1
10/12/05 30.183067 -90.214433 LP-0019 1
10/13/05 30.058467 -90.190617 LP-0020 8
10/13/05 30.111067 -90.060733 LP-0021 2
10/12/05 30.331333 -90.262367 LP-0022 4
10/14/05 30.181117 -89.816133 LP-0023 <1
10/13/05 30.177100 -90.334933 LP-0024 <2
10/11/05 30.232417 -90.065167 LP-0025 4
10/12/05 30.227017 -90.278083 LP-0026 <1
10/12/05 30.227017 -90.278083 LP-0026R <1
10/12/05 30.311633 -90.098050 LP-0027 3
10/13/05 30.079833 -90.356150 LP-0028 10
10/13/05 30.075050 -90.134700 LP-0029 4
10/12/05 30.298383 -90.200000 LP-0030 <1

Table 2. Enterococci results from Leg 3, Lake Pontchartrain

Sample Date

Lat DD
(N)

Long DD
(W)

 KAT Station number

Enterococci
Colonies/100 ml
10/11/05 30.165817 -90.030217 LP-0001 <1
10/14/05 30.170883 -89.752317 LP-0002 <1
10/12/05 30.217483 -90.212250 LP-0003 <1
10/14/05 30.108550 -89.789700 LP-0004 <1
10/11/05 30.202467 -90.018800 LP-0005 <1
10/11/05 30.202467 -90.018800 LP-0005R 1
10/12/05 30.244317 -90.258417 LP-0006 <1
10/14/05 30.302133 -89.996433 LP-0007 <1
10/14/05 30.302133 -89.996433 LP-0007R 1
10/13/05 30.095750 -90.358417 LP-0008 <2
10/11/05 30.226333 -90.103150 LP-0009 <1
10/11/05 30.220950 -89.950483 LP-0010 <1
10/12/05 30.139667 -90.219783 LP-0011 <1
10/13/05 30.108433 -90.252317 LP-0012 <2
10/13/05 30.112967 -90.143683 LP-0013 <2
10/12/05 30.332167 -90.183833 LP-0014 <1
10/14/05 30.170733 -89.704017 LP-0015 1
10/13/05 30.080833 -90.301133 LP-0016 <2
10/13/05 30.080833 -90.301133 LP-0016R <2
10/11/05 30.115500 -89.941667 LP-0017 <1
10/14/05 30.269250 -90.029367 LP-0018 <1
10/12/05 30.183067 -90.214433 LP-0019 <1
10/13/05 30.058467 -90.190617 LP-0020 1
10/13/05 30.111067 -90.060733 LP-0021 <2
10/12/05 30.331333 -90.262367 LP-0022 <1
10/14/05 30.181117 -89.816133 LP-0023 <1
10/13/05 30.177100 -90.334933 LP-0024 <2
10/11/05 30.232417 -90.065167 LP-0025 1
10/12/05 30.227017 -90.278083 LP-0026 <1
10/12/05 30.227017 -90.278083 LP-0026R <1
10/12/05 30.311633 -90.098050 LP-0027 <1
10/13/05 30.079833 -90.356150 LP-0028 <2
10/13/05 30.075050 -90.134700 LP-0029 <2
10/12/05 30.298383 -90.200000 LP-0030 <1

Conclusions

In evaluating the enterococci results, EPA uses a single sample maximum (SSM) in the water quality criteria recommendations developed by EPA in 1986 (EPA440/5-84-002). EPA compares the result with both the SSM for a designated bathing beach area, which represents the greatest amount of full-body contact exposure, and the SSM for infrequently used full-body contact recreation, which represents the lowest amount of exposure. Based on the sampling (October 10-14, 2005), EPA has found that enterococci SSM at Lake Pontchartrain stations 1-30 were all below the most stringent SSM level which is typically used to characterize designated bathing beach areas. The waters in these areas are suitable for all primary contact recreations, which includes swimming.

Fecal coliform data collected from the Lake Pontchartrain sites were below the EPA criteria of 200 fecal coliforms/100 ml. Half of the fecal coliform counts were <1 CFU/100 ml, with sixteen stations ranging from 1-12 CFU/100 ml.

These results should not be used to assess the safety of consuming raw or undercooked molluscan shellfish (such as oysters). This is because the water quality criteria recommendations against which the monitoring data are compared are different between recreational (enterococcus) and shellfish (fecal coliforms) uses, and because accidental ingestion of water presents different risks than eating raw or undercooked shellfish. Nevertheless, these results are valuable for identifying trends in the level and extent of contamination. The state molluscan shellfish program can use these results in planning when to do fecal coliform monitoring and as a basis for deciding whether to reopen harvesting areas, as provided under state regulation and the National Shellfish Sanitation Program.

Test results

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Flood Water Testing Summary

Environmental Assessment Summary for Areas of Jefferson, Orleans, St. Bernard, and Plaquemines Parishes Flooded as a Result of Hurricane Katrina (December 6, 2005)

Biological testing: total coliforms and E. coli

EPA, in coordination with the Louisiana Department of Environmental Quality, is collecting and analyzing biological pathogen data. Flood water sampling data for biological pathogens from Sept. 3 on are being posted as they become available. To date, E. coli levels remain greatly elevated and are much higher than EPA’s recommended levels for contact. Based on sampling results, emergency responders and the public should avoid direct contact with standing water when possible. In the event contact occurs, EPA and CDC strongly advise the use of soap and water to clean exposed areas if available. Flood water should not be swallowed and all mouth contact should be minimized and avoided where possible. People should immediately report any symptoms to health professionals. The most likely symptoms of ingestion of flood water contaminated with bacteria are stomach-ache, fever, vomiting and diarrhea. Also, people can become ill if they have an open cut, wound, or abrasion that comes into contact with water contaminated with certain organisms. One may experience fever, redness, and swelling at the site of an open wound, and should see a doctor right away if possible.

Test results

More information about fecal coliform and E. coli

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Chemical testing

Summary of results beginning September 25, 2005 (after Hurricane Rita)
Summary of results from September 10-19, 2005 (between Hurricanes Katrina and Rita)

Summary of results beginning September 25, 2005 (after Hurricane Rita)

The flood water sample for October 19, 2005 indicated manganese was detected at a level that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

The flood water sample for October 18, 2005 indicated manganese was detected at a level that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

The flood water sample for October 17, 2005 indicated that no metals or organic chemicals were detected at levels exceeding EPA drinking water MCLs or ATSDR/CDC health guidance values. EPA and ATSDR/CDC still recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

The flood water sample for October 16, 2005 indicated that thallium was detected at a level exceeding the EPA drinking water MCL and the ATSDR/CDC health guidance values. Manganese was also detected at a level that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

The flood water sample for October 15, 2005 indicated that manganese was detected at a level that exceeded the ATSDR/CDC health guidance value. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 14, 2005 indicated that manganese was detected in two samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 13, 2005 indicated that manganese was detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 12, 2005 indicated that manganese and vanadium was detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 11, 2005 indicated that antimony and thallium were detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. Manganese was detected in four samples and vanadium was detected in two samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 10, 2005 indicated that arsenic was detected in two samples that exceeded the EPA drinking water MCL. Manganese was detected in four samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 9, 2005 indicated that thallium was detected in one sample that exceeded both the EPA drinking water MCL and the ATSDR/CDC health guidance values. Manganese was detected in four samples, vanadium was found in three samples, and barium was detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 8, 2005 indicated that thallium was detected in two samples that exceeded the EPA drinking water MCL and lead was detected in one sample that exceeded the EPA drinking water action level. Manganese was detected in three samples and vanadium was detected in two samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 7, 2005 indicated that thallium was detected in two samples that exceeded the EPA drinking water MCL and arsenic was detected in one sample that exceeded the EPA drinking water MCL. Manganese was detected in two samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for October 6, 2005 indicated that manganese was detected in four samples and vanadium was detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 5, 2005 indicated that cadmium and beryllium were detected in one sample that exceeded the EPA drinking water MCL. Manganese was detected in three samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 4, 2005 indicated that arsenic was detected in one sample that exceeded the EPA drinking water MCL. Manganese was detected in three samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 3, 2005 indicated that arsenic was detected in one sample that exceeded the EPA drinking water MCL. Manganese was detected in three samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 2, 2005 indicated that Manganese was detected in three samples, and hexavalent chromium was detected in one sample at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for October 1, 2005 indicated thallium was detected in seven samples at levels that exceeded both the EPA drinking water MCL and the ATSDR/CDC health guidance values. Antimony was detected in four samples at levels that exceed the ATSRD/CDC health guidance values and of those four samples, two also exceeded the EPA drinking water MCL. Manganese was detected in six samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for September 30, 2005 indicated thallium was detected in eight samples at levels that exceeded both the EPA drinking water MCL and the ATSDR/CDC health guidance values. Lead was detected in one sample at a level that exceeded the EPA drinking water action level, and arsenic was also detected in one sample at a level that exceeded the EPA drinking water MCL. Antimony was detected in three samples at levels that exceeded the ATSDR/CDC health guidance values, and manganese was detected in eight samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves, boots, and safety glasses, should be worn by emergency responders.

Flood water samples for September 29, 2005 indicated that arsenic was detected in one sample that exceeded the EPA drinking water MCL. Manganese was detected in six samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not believe that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for September 28, 2005 indicated that Polychlorinated Biphenyls (PCBs as Aroclor 1254) was detected in one sample above EPA's drinking water MCL. EPA and ATSDR/CDC do not feel that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). Manganese was detected in four samples that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for September 27, 2005 indicated that arsenic was detected in two samples that exceeded the EPA drinking water MCL. Lead was detected in one sample that exceeded the EPA drinking water action level. Manganese was detected in six samples at levels that exceeded the ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not feel that these levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for September 26, 2005 indicated that manganese was detected at concentrations that exceeded ATSDR/CDC health guidance values. EPA and ATSDR/CDC do not feel that manganese levels pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Flood water samples for September 25, 2005 indicated that arsenic was detected in four samples and exceeded the EPA drinking water MCL in one of these samples. Lead was detected in three samples and exceeded the EPA action limit in one of these samples. Manganese was detected at levels that exceeded ATSDR/CDC exposure scenarios for sensitive populations in five samples. EPA and ATSDR/CDC do not feel that chemicals exceeding EPA drinking water standards or ATSDR/CDC heath guidance values pose a human health threat as ingestion of flood water should not be occurring (unless there is inadvertent ingestion e.g., from splashing). EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. Personal protective equipment, such as gloves and safety glasses, should be worn by emergency responders.

Test results

Summary of results from September 10-19, 2005 (between Hurricanes Katrina and Rita)

EPA in coordination with the Louisiana Department of Environmental Quality performed chemical sampling of New Orleans flood waters for over one hundred priority pollutants such as volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), total metals, pesticides, herbicides, and polychlorinated biphenyls (PCBs). The data have been reviewed and validated through a quality assurance process to ensure scientific accuracy. The data were compared to EPA's drinking water MCL's (Maximum Contaminant Levels) and action levels or to health guidance values calculated by ATSDR/CDC. ATSDR Minimum Risk Levels (MRLs) exist for some chemicals and levels measured were compared to MRLs, when available. For hazardous substances for which there are no MRLs, ATSDR/CDC developed exposure models based on current available toxicity information. MRLs are available at http://www.atsdr.cdc.gov/mrls.html.

Lead was commonly detected at levels exceeding the EPA drinking water action level. Arsenic, barium, thallium, chromium, benzene, selenium, and cadmium were detected in some samples at levels that exceeded EPA drinking water MCLs. Several chemicals, such as hexavalent chromium, manganese, p-cresol, toluene, phenol, 2, 4-D (an herbicide), nickel, aluminum, copper, vanadium, zinc, and benzidine were detected in flood water and compared to ATSDR/CDC health guidance values but were determined not to be immediately hazardous to human health. EPA and ATSDR/CDC have concluded that chemicals exceeding drinking water standards or CDC/ATSDR health guidance values do not pose a human health threat as ingestion of flood water should not be occurring unless there is inadvertent ingestion (e.g., from splashing). Trace levels of some organic acids, phenols, trace cresols, metals, sulfur chemicals, and minerals associated with sea water were also detected.

EPA and ATSDR/CDC recommend avoiding all contact with flood water, where possible, and washing with soap and water should contact with flood water occur. EPA and ATSDR/CDC conclude that exposures at these levels during response activities are not expected to cause adverse health effects as long as the proper protective equipment is worn such as gloves and safety glasses.

Test results

Additional information

Additional information regarding health and safety issues for both the public and emergency responders can be found on the Centers for Disease Control (CDC) Web site and the Occupational Safety and Health Administration (OSHA) Web site.

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