EPA's Response Team is blocking one lane of traffic in front of the residence and the sidewalk has been closed. The Team requests neighbors and visitors to the Site exercise caution.

   On May 23, 2023, Davis County Department of Health requested assistance from Utah Department of Environmental Quality (UDEQ) at a private residence in North Salt Lake, Utah. The residence contains numerous containers of hazardous chemicals that were collected by the resident over approximately 30 years. The chemicals include several gallons of elemental mercury. The mercury has escaped containment and is affecting indoor air quality.

   UDEQ staff visited the residence and quickly referred the incident to EPA Emergency Response. EPA deployed a Response Team to the residence on June 5, 2023 to secure and dispose of the chemicals as well as address mercury contamination in the home. The majority of the chemicals are in the garage of the residence. Most of the containers are intact and there is significant mercury contamination in the garage.

• Safety of the public and response personnel is top priority.
• Stabilize the source area to prevent the release of hazardous substances.
• Minimize or eliminate threats to human health posed by the hazardous chemicals.
• Collect, bulk and dispose of hazardous chemicals.
• Provide timely and accurate communication of response information to the public and stakeholders.

1. Establish air monitoring in and around the residence.

2. Begin to address mercury contamination in garage.

3. Begin to process chemical containers in garage.

4. Evaluate mercury contamination in home.

   EPA's Response Team established its work zones and began air monitoring for mercury and VOCs in and around the residence. Readings showed significant mercury contamination in the garage. Although the data from the living space of the residence indicates that the indoor air quality has been affected by the mercury in the garage, no discrete sources of elemental mercury have been detected inside the home at this time. No levels of concern were detected along the perimeter of the property.

   The Team is currently focused on the garage of the residence. The containers that were known to contain mercury were collected and secured in new containers. The crew used mercury specific vacuums to collect beads of elemental mercury in the garage and began mercury decontamination procedures on the homeowners' belongings in the garage. The Team also began inventorying the chemical containers in the garage for disposal.

   Officials from Davis County Health Department and UDEQ visited the Site. South Davis Metro Fire's HazMat Team toured the Site to review hazards and Site conditions should their assistance be required.

1. Continue air monitoring in and around the residence.

2. Continue to address mercury contamination in garage.

3. Continue to process chemical containers in garage.

   EPA's Response Team performed a secondary screening of the living areas in the residence. At this time, results continue to indicate that there is not a source of recoverable mercury in the home. This suggests that the indoor air contamination is a result of the mercury in the garage. As a precaution, the Team plans to dispose of several floor rugs and will decontaminate some flooring in high traffic areas to/from the garage. A limited section of carpeting may also be removed.

   The Team is still working its way through mercury contamination in the garage. Crew members are discovering beads of mercury, especially in one area towards the back. Personal items are being removed from the garage and tested. Most items are showing contamination. The crew erected a tent to facilitate the decontamination these items. The decontamination process involves using a chemical reagent to bind the mercury and/or allowing the items to vent. Air monitoring data is being collected inside and outside the tent throughout this process. The items will then be screened for mercury once again before being returned to the property owner. Items that cannot be decontaminated are being disposed of.

   The Team is also continuing to collect and process other chemicals from the garage for disposal.  These chemicals are being sorted into hazard classes and waste streams before being packaged into secure containers for transport.

   The Response Team is working long hours and posting a night watch during the overnight hours.

   Air monitoring results from outside the garage including the decontamination tent continue to show no levels of concern.

1. Continue air monitoring in and around the residence.

2. Continue to address mercury contamination in garage.

3. Continue to process chemical containers in garage.

   EPA's Response Team is making every effort to decontaminate items in the garage so that they can be returned to the property owner. The process is tedious and involves using a chemical reagent to bind the mercury and/or allowing the items to vent. The items will then be screened for mercury once again before being returned to the property owner. Items that cannot be decontaminated will be disposed of at an appropriate disposal facility. Beads of mercury are still being regularly collected especially in the back of the garage as items are moved for decontamination.

   The Team has made significant progress collecting and packaging containers of chemicals for disposal. These containers are being sorted into hazard classes and waste streams before being packaged into secure containers for transport. There are roughly 10 containers with contents that cannot be identified. These chemicals will be tested and processed on June 9 and all the chemicals should be packaged for transport at that time.
EPA’s Team will be working through the weekend and one lane of traffic will remain closed. The crew will continue to work long hours and post a night watch.

   Air monitoring results outside the garage including the decontamination tent and the perimeter of the property continue to show no levels of concern.

   EPA's Response Team completed its assessment of the hazardous chemicals in the garage. All chemicals have been assigned to disposal waste streams and the majority have been packaged for transport. Arrangements are being made to move the chemicals off-Site.

   The Team is making every effort to decontaminate items in the garage so that they can be returned to the property owner. The process is tedious and involves using a chemical reagent to bind the mercury and/or allowing the items to vent. The items are then be screened for mercury once again before being returned to the property owner. Many items passed screening and were released today. Many items that cannot be decontaminated were also disposed of today. Beads of mercury are still being collected in the garage but their presence is greatly reduced.

   EPA's Response Team transported roughly half of the chemicals collected in the garage to a facility provided by Davis County. The chemicals will be securely stored at this location while arrangements are made for disposal at an appropriate facility.

   The Team removed the vast majority of the personal items from the garage that were contaminated with mercury. Items are continuing to be decontaminated and those things that pass screening post-contamination are being released to the property owner. Items that cannot be decontaminated are being disposed of. Beads of mercury are still being collected in the garage but their presence is greatly reduced.

   The living areas of the residence were screened for a third time. As before, the Team was unable to locate recoverable sources of mercury and air quality measurements for mercury were significantly lower. A surprisingly high reading was measured in a washing machine but it is not impacting indoor air quality. The Response Team has a few theories on how that happened and the situation is being addressed.

1. Continue air monitoring in and around the residence.

2. Continue to address mercury contamination in garage.

   EPA's Response Team completed its effort to remove all chemicals and personal items from the garage. The chemicals are secure and the Team continues to decontaminate personal items. A large number of personal items have been successfully decontaminated and are being returned to the property owner. Items that cannot be decontaminated are being disposed of.

   The Team diligently vacuumed the floor and other hard surfaces in the garage with a vacuum specifically designed to collect elemental mercury beads. A mercury decontamination agent was then liberally applied to these surfaces and the Team has initiated an ongoing operation to heat the garage to roughly 90 degrees Fahrenheit followed by a rapid venting of the garage space. This operation will continue overnight.

   Air monitoring results continue to be collected inside the garage, outside the garage in the Teams work spaces and at the perimeter of the incident. No levels of concern have been collected.

   The Team worked with the property owner to run several hot washing cycles through the washing machine that was found to have elevated mercury levels yesterday. The washing machine was reassessed during this Operations Period and mercury levels were found to be much lower. Air monitoring measurements from the home continue to show reduced levels of contamination.

1. Continue air monitoring in and around the residence.

2. Continue to address mercury contamination in garage.

   EPA's Response Team heated and vented the garage overnight and then conducted an air monitoring sweep this morning. An additional area of tiny mercury beads and several hot spots were detected. The Team vacuumed the floor of the garage again and the mercury decontamination agent was applied to all the hard surfaces for a second time. The Team set up a mercury meter to run overnight in the garage, closed all the doors and windows, and initiated a clearance run. The results of this clearance run will determine whether or not the garage can be occupied by the homeowner once again.

   All remaining chemicals and contaminated items from the garage were packaged and shipped off the property for disposal. All items that could be decontaminated were returned to the property owner. The Team will help the residents move these materials back into the garage after the area is cleared. Two cars were assessed, and no levels of concern were detected. The only area and items left for the Team to assess is a camper that is parked next to the driveway which was inaccessible due while the garage was being cleared out.

   Air monitoring results continue to be collected across the property and no levels of concern have been detected.

1. Complete air monitoring in and around the residence.

2. Complete removal of mercury contamination in the garage.

  EPA’s Response Team let a mercury meter run overnight in the garage to determine residual contamination levels in the garage after the crew had completed its decontamination activities. To clear a residential property for mercury contamination, EPA targets a clearance level of 1,000 nanograms per cubic meter of air collected over an 8-hour period. The readings after all the cleanup work were 350 nanograms per cubic meter. The Team sealed the floor with epoxy as a precaution. The EPA consulted with the Davis County Department of Health and declared EPA’s activities a success.

  The Team entered the family’s tow-behind camp trailer which was the last location that needed to be assessed. No mercury levels of concern were detected.

  The EPA crew completed its assessment of all remaining personal items. The items which could be decontaminated will be moved back into the garage tomorrow.

  Finally, EPA’s Team began to demobilize its response assets. The street is now clear. The last daily update will be tomorrow; materials will continue to be appropriately disposed of.

1. Help homeowners organize cleared items so that the family can reoccupy their garage.

2. Dispose of remaining items from the garage that cannot be decontaminated.

3. Demobilize all response resources.

   EPA's Response Team moved all the items from the garage that were successfully decontaminated to a secure, dry location. The homeowners' extended family is planning a gathering to reoccupy the garage.

   All remaining items that could not be decontaminated were hauled off for disposal.

   All response resources were demobilized and EPA left the Site.

   The Response Team wishes to thank Utah Department of Environmental Quality, Davis County Department of Health and South Davis Metro Fire HazMat for all of their assistance during this emergency response effort.

   The Team also appreciates the patience and friendliness that the neighborhood extended to us during our work. We will miss all the dogs we met.