On January 17, 2008, at approximately 12:15 pm, a student of Mid-Rivers Elementary School in St. Peters, Missouri, broke a mercury thermometer in a second floor hallway of the school building. The thermometer was brought from the students home as part of a science project.
The school custodian initially attempted to clean the spill with a broom and dust pan. The local HAZMAT team responded and reported no visible beads of mercury present at the scene of the spill. An air monitoring assessment was conducted by the U.S. Environmental Protection Agency (EPA) in coordination with the Missouri Department of Natural Resources (MNDR) for mercury vapors. The two agencies had responded to the scene on the evening of January 17. During the EPA/MDNR clean-up assessment, visible beads were observed on the tile of the second floor hallway of the Mid-Rivers Elementary School Building.
Responders utilized a portable mercury vapor analyzer to screen the area for mercury vapors. Mercury vapors levels indicated a small source of elemental mercury in the hallway where the break occurred. Concentrations in other nearby areas, including the floor around the desk of the student who dropped the thermometer showed no signs of elemental mercury.
It was determined that a simple clean-up of the spilled mercury would be adequate. MDNR and EPA responders conducted the clean-up in the elementary school hallway.
Mercury beads were concentrated and collected of from the surface of the floor tile. Beads were collected from cracks between the floor tiles the hallway floor utilizing special tools.
At the completion of the clean-up, no significant amount of elemental mercury was observed. Mercury vapor levels were measured in the area and were found to be below the EPA removal action goals for non-residential sensitive population scenarios.
Elemental mercury that was collected from the clean-up was transferred to the Missouri Department of Natural Resources for disposal.
No further action is planned due to this event.
|