At approximately 1200 hours on Wednesday, 7 September 2016, personnel from the Las Vegas Fire & Rescue contacted EPA’s Environmental Response Team (ERT) - West in Las Vegas to request technical assistance with screening several students for possible mercury contamination at the Walter R. Johnson Junior High School, located at 7701 Ducharme Ave in Las Vegas, NV.  ERT-West notified the Region 9 Phone Duty Officer prior to their departure to the school and followed up with a call describing the mercury levels measured at the school.  Based on these levels, On-Scene Coordinator (OSC) Randy Nattis deployed to the release on Wednesday afternoon.  OSC Nattis was subsequently joined by additional Region 9 personnel including OSC Steve Calanog, a public information officer, and a community involvement coordinator; as well as START contractor personnel and USCG Pacific Strike Team (PST) members.  Working closely with the Las Vegas Fire & Rescue, over 1200 students were screened for mercury contamination; 80 students required some level of decontamination.  On September 12, OSCs Tom Dunkelman and Marty Powell relieved OSCs Nattis and Calanog.

Decontamination of the Junior High School was performed by a contractor hired by the Clark County School District, with cleanup efforts focused on the gymnasium and locker rooms.  EPA, START and USCG PST personnel provided technical assistance to the School District during cleanup of the school.    EPA personnel worked closely with the Southern Nevada Health District (SNHD) to provide information to school officials, teachers, parents and residents about the dangers of mercury exposure.  The Walter R. Johnson Junior HIgh School was re-opened on September 13.

At the request of the School District and as a precaution, EPA conducted assessments at five nearby schools and seven school buses.  No elevated levels of mercury were detected at these locations.  EPA also conducted assessments at more than 100 residences, where it was thought that mercury contaminated materials (clothing and backpacks) might have been transported.  Only one of these residences was found to have elevated levels of mercury.

This home, located at 8353 San Grail Court in Las Vegas, was found to have substantially elevated levels of mercury (in excess of 10,000 ng/cubic meter).  The occupants of the home (two adults and two children) were immediately offered relocation, which was provided by the American Red Cross.  This residence became the focus of the removal action.  All previous assessment work conducted by EPA at the school and at the various residences was considered to be removal assessment.

2.1.1 Narrative
On September 13, EPA, START and USCG Pacific Strike (PST) personnel conducted mercury screening of the residence at 8353 San Grail Court using a Lumex mercury detector.  Elevated levels of mercury vapors were primarily detected in the bedroom of the child who was a student at the Walter R. Johnson Junior High School; although other areas of the house also had elevated levels of mercury vapors.  Beads of visible mercury were observed to be present in the bedroom

The residential property, which was the site of the removal action, is located at 8353 San Grail Court in Las Vegas, NV.  This is a three bedroom residence with a small backyard and side yard.

 A limited amount of mercury appears to have been transported on clothing and on a backpack from the initial spill location at the Walter R. Johnson Junior High School to the residence at 8353 San Grail Court. 

Elevated levels of mercury vapors (greater than 10,000 nanograms/cubic meter) were detected in the residence.  Mercury beads were also identified in the residence.

2.1.2 Response Actions to Date

The EPA ERRS contractor removed all of the contents of the bedroom, including the carpet. Those items that were determined to have elevated levels of mercury (greater than 3,000 ng/cubic meter) were designated for disposal. The remaining items were allowed to air out until mercury vapors had dissipated substantially and were eventually returned.  The floor of the bedroom was treated with raw sulfur, which has then removed with a mercury vacuum. 

On September 14, EPA conducted clearance sampling of the residence at three separate locations and found that mercury vapor concentrations were below 1,000 ng/cubic meter.  At that time, OSC Dunkelman advised the residents that mercury vapor levels in the residence were below ATSDR and EPA standards, and that EPA considered the building safe for reoccupation.  

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

Law enforcement agencies have been investigating the circumstances regarding the release of mercury at the Junior High School and the subsequent contamination of the residence.  

2.1.4 Progress Metrics
Contaminated items from the house were placed in a roll off box, for disposal at US Ecology in Beaty, AZ

* The above accounting of expenditures is an estimate based on figures known to the OSC at the time this report was written. The OSC does not necessarily receive specific figures on final payments made to any contractor(s). Other financial data which the OSC must rely upon may not be entirely up-to-date. The cost accounting provided in this report does not necessarily represent an exact monetary figure which the government may include in any claim for cost recovery.

3.1 Unified Command
N/A - Clark County School District was the Incident Command - Lead
3.2 Cooperating Agencies
Clark County School District

Southern Nevada Health Department

Las Vegas Fire & Rescue 

Las Vegas PD

Red Cross

Total deployed resources (Federal) for the response:

4 OSCs (OSC Nattis, OSC Calanog, OSC Dunkelman, OSC Powell)

2 PIO

1 CIC 

4 ERT

5 USCG 

7 START contractors

2 SERAS contractors

3 ERRS contractors

http://www.atsdr.cdc.gov/substances/toxsubstance.asp?toxid=24

 http://www.atsdr.cdc.gov/emergency_response/Action_Levels_for_Elemental_Mercury_Spills_2012.pdf