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2.1.1 Narrative
The EPA OSC and 2 START responders were deployed and arrived in Post Falls late evening, November 24, 2015. Two additional START responders with a response rig, equipment, and supplies departed the morning of November 25, 2015, arriving later that day.
The OSC, START, and an EPA ERRS contractor (ERRS) representative, attended an 0800 Situational Briefing at the school with School Clergy/Staff, Idaho Department of Environmental Quality (DEQ), Panhandle Health District 1, and Kootenai County Fire/Regional Response Team personnel. Unified Command (UC) was established and roles, resources, and a preliminary Incident Action Plan were established.
Sixteen high school students were identified as having some form of exposure to mercury during the two days of release and clean up. In order to evaluate potential migration of mercury contamination from the school to the homes and families of the sixteen students, the UC established a primary objective of assessing the public health exposure of the students and families by assessing each of the 16 homes.
The UC established 1000 ng/m3 as the residential action level for residential ambient air and building surfaces and identified an action level range of 1000 to 3000 ng/m3 for school/Chapel ambient air and surfaces. During home assessments, if personal effects were found to be contaminated up to 3000 ng/m3, the Assessment team would advise the families to retain for use or they could dispose of in regular municipal waste. If personal effects were found to be contaminated between 3000 and 6000 ng/m3, the Assessment team outlined 3 options: 1. continue using; 2. provide to Team for decontamination/possible return, or; 3. dispose of in regular municipal waste. If personal effects were found to be contaminated above 6000 ng/m3, the Team strongly urged the homeowner to relinquish the item for decontamination and possible return. Any contaminated items were bagged and transported to the Decontamination Area.
2.1.2 Response Actions to Date
Wednesday, November 25 - Two 2-person Lumex air monitoring teams (START and RRT) were dispatched to assess students personal effects that had not been turned in already and assess their family's homes (bedroom, shoes, entryway, washer, dryer, backpacks, etc.). A total of 7 homes were assessed with one home having a hotspot in the student's bedroom. Several items (municipal trash can, vacuum cleaners, additional student clothing/shoes, backpacks) were bagged, removed from a few homes and transported to the Decontamination Area at a later time. The parents in the house with a contaminated hotspot were advised to isolate the student's room, have the boys sleep elsewhere, raise the heat and ventilate the room overnight followed by reassessment the next day.
A third 2-person Lumex air monitoring team (RRT) reassessed the Chapel's two floors, confirming the ambient air and floor concentrations found in an earlier survey. A hotspot was found in the janitorial closet due to a contaminated broom being placed in the closet. Because the ambient air concentrations fell below the 3000 ng/m3 action level, the UC determined that the Chapel could be reopened for services but the janitors closet would remain closed off until decontamination could be effected.
The ERRS made an entry into the South School Building and recovered all mercury containers, inventoried and secured in a safe, controlled location. The ERRS also inventoried the contents of all the bags of personal belongings brought to the school by students and their families. A vial of mercury (1 of 3 believed to have been taken home by students) was returned in one of the student's bags dropped at the school on Tuesday, November 24.
Thursday, November 26 - Two 2-person Lumex air monitoring teams (START) continued assessing students' homes and belongings. An additional 7 homes were assessed, two of which had elevated ambient air concentrations and one floor hotspot in each, associated with the students' bedrooms. Some personal items were identified as contaminated and bagged for removal/decontamination. One of the teams reassessed the elevated home identified on November 25 and determined to be below the Action Level of 1000 ng/m3.
The ERRS procured two shipping containers (Conex) to be utilized for storage and thermal decontamination. The ERRS segregated bags of personal belongings into 3 contamination categories (Low, Medium, High) by headspace measurement of the opened bags, after the bags were brought to room temperature in a Conex box. Uncontaminated or Low contaminated bags were opened at the top and placed in a Conex box for heating. Quality assurance spot checks were conducted after heating via small forced air to confirm that the initial screening was accurate and test efficiency of thermal treatment. The contents of Medium contaminated bags were removed and hung up in the second Conex box for thermal treatment/decontamination. Large forced-air heaters were placed at the front of the Conex boxes to warm the contents for measurement and/or treatment.
Friday, November 27 - One Lumex air monitoring team assessed the 15th of the original 16 targeted homes. Additional student personal belongings bagged and removed for decontamination. A hotspot in student's room pegged at 50,000 ng/m3. OSC and team advised family to mitigate with isolation, heat and ventilation and we would return for reassessment. A second Lumex air monitoring team entered the 2nd floor of the south school building to reassess ambient air levels and surfaces.
It was reported earlier in the week that the student in the 16th targeted home (residing in Washington State) had taken home a vial of mercury and that the family was not consenting to grant access to an air monitoring team to assess their home. Repeated contact by the Clergy and school officials was not effective at gaining access. A review of the records by school officials found a potential error in record-keeping about who took home vials of mercury. The parent of the student in the 16th home, verbally confirmed with a school official that no vials of mercury were brought home.
The ERRS commenced with decontaminating the 2 classrooms with the highest contamination, using a mercury absorbent/cleaning agent and elevated heat with ventilation. Reassessment of cleaned rooms found elevated levels. Plan was to increase heat, modify heating patterns and adjust window openings to focus thermal treatment on two cleaned rooms overnight. The ERRS also continued thermal treatment of personal belongings and a START assisted with managing the inventory and measurement of efficacy. Approximately 75% of the medium contaminated belongings were determined to be cleaned below the action level of 3000 ng/m3 and were staged in a clean room for return to families. Items not deemed cleaned yet will be put back through a second round of thermal treatment.
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
To be determined.
2.1.4 Progress Metrics
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