On 3/9/2011 EPA and START observed elevated concentrations of mercury in the crawlspace of 5 ug/m^3 in breathing space and 20 ug/m^3 in the corner below the spill area with an air temperature of 45 degrees. ERRS removed approximately 6 inches of soil in the crawlspace. Due to the high concentrations in the crawlspace ERRS installed a ventilation system in the basement to draw vapors away from the house. The ventilation system moves 11,000 cubic feet of air per hour. EPA and START screened bagged items from the kitchen after heating them to 70 degrees. All items with concentrations higher than 10 ug/m^3 were discarded. ERRS heated foundation bricks and concrete in the crawlspace with a butane torch to vaporize residual mercury. ERRS also removed some concrete in the crawlspace to reach potential mercury contamination. START conducted air monitoring during torch heating to ensure air concentrations did not exceed ppe upgrade levels. After allowing the crawlspace to cool START observed concentrations of 0.7 ug/m^3 in breathing zone. Early readings indicate that significant source was removed during the crawlspace clean-up effort.

On 3/10/2011 ERRS continued to heat crawlspace with butane torches. START observed mercury levels of 0.5 ug/m^3 in breathing zone. The kitchen was re-screened after significant source was removed from the crawlspace. Concentrations of mercury were still at 4 ug/m^3 near baseboards in the kitchen and 4 ug/m^3 near kickstop under the counter. ERRS removed the remainder of the baseboard and kickstop and vacuumed with mercury vacuum. ERRS set up propane heaters and heated and vented the kitchen for an hour. Temperatures in the kitchen reached over 100 degrees during heating and venting. After allowing the temperature to stabilize to 77 degrees, START observed levels of 3.2 ug/m^3 in the breathing zone with no ventilation. EPA observed consistently higher concentrations near the floor, leading to the conclusion that a large portion of the floor likely absorbed some mercury from the spill.

The remainder of the house was also sealed and heated to take initial readings and determine if any mercury vapors had spread through the house. Temperatures in the remainder of the house were upwards of 85 degrees 
 and mercury concentrations of 0.2 ug/m^3 in the breathing space were consistent in each room of the house, excluding the kitchen. These readings suggest that the remainder of the house is not contaminated and will likely pass the 8 hour final screening test.

On 3/11/2011 ERRS began preparation for removal of the floor. Plastic was installed beneath the kitchen floor from the basement to catch debris and any mercury that fell down during demo. The entire floor in the kitchen was removed as well as the portion of the subfloor closest to the spill. All areas were vacuumed with the mercury vacuum after removal was complete. START collected a bulk sample of the wall nearest to the spill location for asbestos analysis in the event that the wall should need to be removed. After removing the floor and under vented conditions EPA and START observed mercury concentrations of 6 ug/m^3 near spill location. The remainder of the subfloor did not demonstrate mercury levels above ambient conditions.

2.1.2 Response Actions to Date

• Removed and bagged all personal items in the kitchen.
• Removed visible mercury with a mercury vacuum.
• Removed the cabinet and counter where the spill occurred.
• Wiped and vacuumed kitchen to remove all residual mercury.
• Screened the resident’s car, clothing and hotel rooms.
• Vacuumed and removed soil from a crawlspace below the kitchen where high concentrations of mercury were discovered.
• Heated and vented the kitchen.
• Removed more soil from the crawlspace to bring mercury levels down.
• Heated crawlspace bricks and concrete with butane torch in order to volatilize residual mercury.
• Heated to over 100 degrees and vented the kitchen.
• Heated the remainder of the house to 80 degrees and obtained mercury concentrations of .2 ug/m^3.
• Removed the floor and a portion of the subfloor and vacuumed all exposed areas

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

2.1.4 Progress Metrics

• Continue heating and venting kitchen
• Epoxy seal exposed wood in spill area and concrete foundation below
• 8 hour home clearance
• Repair damaged counter top and restore kitchen to livable condition
• Disposal of waste generated on site

2.2.1.1 Planned Response Activities

2.2.1.2 Next Steps

2.2.2 Issues