On 27 June 2007, the Louisiana Department of Environmental Quality (LDEQ) contacted the EPA Region 6 hotline to report a mercury release at a home in Chalmette Louisiana. The EPA subsequently notified the National Response Center (NRC 840234) of the release. The release was originally reported to the LDEQ by the Children’s Hospital of New Orleans, La. The residents’ youngest child became ill a few weeks ago and was being treated at the Children’s Hospital. After several examinations, the residents brought to the doctor’s attention that they recently had found mercury within their home. The child was then tested for mercury poisoning, and tests indicated that the child had mercury levels approximately 40 - 70 times that of normal levels.
On 28 June, START-3 conducted an assessment of the residence. Initial air monitoring conducted by START-3 indicated levels of mercury in air of up to 60 micrograms per cubic meter (μg/m3). Based upon the START-3’s report, EPA senior management was briefed on the situation. On the morning of 29 June, ERRS was verbally tasked to conduct a site walk that same day utilizing the OSC’s warrant authority for emergency actions.
July 13, 2007: work resumed. Initial air monitoring indicated mercury vapor in bedrooms #1, #2, #3, and the garage at 0.3, 0.4, 0.3, and 0.7 μg/m3, respectively. The kitchen was sealed and monitored later in the day; mercury vapor was observed at approximately 1.8 μg/m3. The baseboard areas in the living room were re-screened. The area with over 140 μg/m3 remained. Personal item screening and documentation continued. All drains were treated with Mercongel and will be allowed to set in the drains overnight. Prior to treatment with the Mercongel, the drains, sinks and tubs, were monitored for mercury vapor. All of the sinks have “P” traps installed and contained mercury vapor approximately that of interior air background levels, with the exception of the kitchen sink. Once the garbage disposal was removed, the mercury vapor in the sink fell back to interior air background levels. The bathtubs contained mercury vapor at 14 and 130 μg/m3. A 25yd3 roll-off box of mercury contaminated household debris was taken off-site for disposal; the debris will be taken to Woodside Landfill located in Walker, La. Another 25 yd3 roll-off delivered while the transported was on-site. Overnight site security was maintained.
July 14, 2007: work resumed. In the vented areas of the house, initial monitoring indicated mercury vapor around 1 μg/m3. Continued decontamination around baseboard areas. After the Mercongel was allowed to treat the drains overnight, the drains were flushed with water for at least 20 minutes per drain. After the flushing, the drains were re-monitored. The mercury vapor in the drains was approximately that of the measurement prior to treatment with Mercongel. The drains were flushed with water. Continued to screen personal items, but slowed due to inclement weather. Overnight security was maintained. The house was heated and vented overnight.
July 15, 2007: work resumed. The entire house was heated and vented excluding 1 of 3 bedrooms and one of the bathrooms, which previous monitoring has indicated the mercury vapor levels are below the ATSDR 1 μg/m3 clean-up level. These rooms were vented only. No interior readings were collected today. Most of the crew took the day off. Only 1 crew member remained on-site during the day to provide site security. Overnight security was maintained.
July 16, 2007: work resumed. During venting of the house, mercury vapor was observed between 0.2 to 1.2 μg/m3. After treatment with Mercongel, both bathtub drains still contained elevated levels of mercury vapor; mercury vapor was observed as high as 78 μg/m3. All other drains with “P” traps installed had mercury vapor around background levels. All drain vapor readings were taken with intake placed directly into the drain opening. Scanning along the Northern wall in the living room revealed areas still greater than 140 μg/m3. Mercury vapor was measured in the interior walls; the same walls where elevated levels of mercury vapor was observed along the baseboard areas. Vapor was measured in the interior of the walls; readings were taken directly through 2 holes drilled into the walls from the attic; monitoring indicated mercury vapor at levels between 1.1 to 2.5 μg/m3. Due to inclement weather, personal item screening and perimeter monitoring was not conducted. Overnight security was maintained.
Continue the heating-venting of the house, monitor the indoor air and re-assess the situation for process modifications. The areas along the walls where elevated mercury readings are observed may have the sheetrock removed to allow access to the mercury contamination. The bathtub drains will be access, and decontaminated. The screening, segregation, and deconning of the personal property will continue until completed.
Source of the mercury release has not been identified.
All members of the familiy except the daugther have elevated levels of mercury in their systems.
There is a heighten community concern most likely due to the mercury-contaminated residence being in the footprint of the Murphy Oil release. However, numerous analytical results of the materials from the Murphy Oil release indicated non-detects for mercury.
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