On Oct. 21, 2024, EPA received notification from Iowa Department of Natural Resources (IDNR)
that a residence in Dallas Center, Iowa had been impacted by a 2-3 tablespoon
mercury spill. The mercury spill was discovered on the floor of the basement by
one of the residents on Oct. 20. The spill occurred 18 months earlier when a
resident knocked over a glass jar of mercury that had belonged to a now
deceased relative, resulting in the release.
IDNR submitted a Request for Federal Action to EPA on Oct. 22. EPA On-Scene
Coordinators (OSCs) mobilized to the residence to investigate the mercury spill on Oct. 22. EPA OSCs documented mercury vapor readings above
300,000 ng/m^3 and viewed small pools and microbeads of mercury in the basement
area. EPA OCS also documented mercury vapor readings above 100,000 ng/m^3 on the
main and second floor of the residence.
A cleanup was warranted due to the visual confirmation of elemental mercury in the basement and the high mercury vapor levels in the home. This
incident occurred within EPA Region 7 jurisdiction and EPA assumed lead of the response action.
EPA contractors
mobilized to the site on Wednesday, Oct. 23 and started cleanup activities.
The cleanup efforts included the removal of elemental mercury; removal of impacted residential items; and the sealing of impacted construction features. Residents were relocated from the home on Oct. 22.
From Nov. 25 through Nov. 26, EPA took two, eight-hour time-weighted average samples using two Ohio Lumex 915M handheld MVAs. Sample results were below the action level of 1,000 ng/m3 for mercury vapor.
Based on the results, the OSC determined that work to remove mercury from the home was complete on Nov. 27. EPA demobilized and the residents moved back in to the home.
