Boulder Valley School District

Marshall Fire Air Quality Information

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BVSD is concerned about both the mental and physical health and well-being of our students and staff following the Marshall Fire. Understandably, air quality in and around our buildings is a priority. Providing a safe indoor environment that is free of hazards at concentrations of concern is as important to BVSD as it is to our families and staff.  


BVSD is working with our partners at Boulder County Public Health (BCPH) as well as our restoration contractor ATI and industrial hygiene consultant, Clark Seif Clark, Inc. for guidance related to providing a safe environment for students and staff in the areas affected by the Marshall Fire. BCPH has stated that it “strongly supports the resumption of classes at BVSD schools including those near the burn area, as well as the efforts the district has taken to ensure student safety.” The Colorado Division of Fire Prevention and Control inspected all buildings and deemed them safe to occupy.

Indoor Air Quality

All outside air intake into buildings were closed before the smoke plume arrived and remained off until evacuation orders were lifted. This proactive action greatly reduced the potential intrusion of combustion byproducts into the buildings through the HVAC systems. The initial visual inspection of the interior of the buildings confirmed no accumulations of settled combustion byproducts through the HVAC system. Small amounts of settled combustion byproducts were found at some doors, leaky window sills, or skylights. 

Although there was little combustion byproduct visible inside the buildings, out of an abundance of caution, BVSD hired two professional fire/disaster remediation firms to thoroughly clean the eight affected schools. ATI and ServPro entered buildings as soon as BVSD was given access and performed specialty cleaning to return the buildings to their pre-event condition and enable us to open schools. This included:

  • All horizontal surfaces were wet wiped with microfiber towels.

  • All rugs, carpets, and furniture were HEPA vacuumed. 

  • Hard surface floors were wet mopped.

  • Air filters in HVAC units were changed after the fire and will continue to be replaced as needed.

  • Ductwork cleaning has been completed at the affected schools. 

  • Dozens of professional-grade, HEPA equipped air filtration devices or AFDs were deployed to schools to run nightly. They are high volume, moving 500 to 2,000 cubic feet of air per minute through the HEPA filter. These devices recirculate air in the spaces where they are set up, filtering air as it moves through the machine. The movement of the air stirs up settled particulates so they can be drawn through the device and filtered out of the air. 

  • There were in excess of 60 staff from ATI on site at any given time which flexed to as many as 100 when needed. ServPro had 60 people cleaning two schools. Crews were onsite 12 hours each day prior to reopening. 

  • Hydroxyl generators were used to address odors in the buildings. 

  • Air purifiers which were deployed to schools in response to COVID are still operating in schools. HEPA and activated charcoal filters were changed in these devices in December 2021. The activated charcoal filters absorb VOCs and odors. 

Outdoor Environment on School Sites

  • We are relying on our partners in public health for guidance about outdoor air quality related to having schools open and conducting outside activities. BCPH is working to set up outdoor air monitors in the burn areas and will be our source of information concerning outdoor air quality. If BCPH advises that outdoor air quality is at a level that restricts outdoor activities, schools will be advised and respond accordingly. Likewise ventilation systems will be adjusted to reduce outside air intake. 

  • Play equipment on playgrounds has been power washed with surfactants and degreasers.  

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