Marshall Fire: Air, Soil and Water Quality
Aerial View of Boulder, Colorado

Marshall Fire: Air, Soil and Water Quality

Air Quality Data and Measurements

People living, working or traveling in and around the Marshall fire burn areas can opt-in for text and email alerts to access instant, real-time, air quality information 24/7 from up to 25 particulate monitors strategically positioned throughout areas affected by the Marshall fire and in the surrounding communities, including a dedicated monitor for all schools in burn areas.

Learn more and subscribe for air quality updates

Measurement of Volatile Organic Compounds (VOCs)

Preliminary analysis of outdoor air measurements conducted by the National Oceanic and Atmospheric Administration (NOAA) in areas affected by the Marshall fire has found that levels of volatile organic compounds are comparable to ordinary urban air pollution.

Colorado Department of Public Health and Environment (CDPHE) will monitor for volatile organic compounds with a mobile unit equipped with advanced technology that can monitor for air quality while in motion.

Some residents have purchased at-home, low cost air quality monitors, which can be helpful. However, it is important to understand their limitations. Keep in mind that there is no assurance that any individual monitor has been properly configured, deployed or maintained.

Please watch this video for more information about VOCs and at-home air monitors.

Staying Safe from Air Pollutants

If you are resident in a burn area or live downwind, please take these precautions:

  • On windy days, limit outdoor activity in the affected communities or stay inside and keep windows and doors closed. If you must be outside on a windy day, wearing an N95 mask is recommended.
  • Anyone with respiratory illnesses is advised to talk with their healthcare provider about what to do to stay safe.
  • Residents should be aware of their indoor air quality as well. The ash and soot from the fire contain volatile organic compounds and other harmful contaminants, such as heavy metals that can linger in homes if not properly removed. Particulates are microscopic and may appear as ash in some homes and may not be visible in others. Take care not to track ash into your home on shoes or clothing.
  • Some websites and weather apps may report the region’s air quality to be good or moderate. However, it is important to note that these sources may be getting their information from monitoring devices located too far away from the affected areas to provide an accurate reading.

Indoor Air Quality

It is important to monitor indoor air quality. Ash and soot from the fire contains volatile organic compounds and other harmful contaminants, such as heavy metals, that can linger in homes if not properly removed. Particulates are microscopic and may appear as ash in some homes and may not be visible in others. Take care not to track ash into your home on shoes or clothing.

If you experience non-specific health effects (headaches, eye irritation or nosebleeds), it is recommended that you consult a professional regarding cleaning and restoration as these may be symptoms of odor-free contaminants that can cause irritation.

Poor air quality can cause some of the same symptoms as COVID-19. If you are experiencing symptoms similar to COVID-19, talk to your health care provider, do not go to work or school, stay home, get tested and follow guidance on isolation and quarantine.

Healthy Homes

Boulder County Public Health recommends getting HVAC ducts cleaned by a professional as soon as possible and replacing filters as soon as they appear soiled. Use the highest level of filtration recommended by the HVAC manufacturer whenever possible and consider installing an activated carbon pre-filter to help reduce odors.

Water Quality after a Fire

A research team from the University of Colorado Boulder is monitoring post-fire impacts to water quality and ecology in Coal Creek in the wake of the Marshall Fire, with support from the Keep it Clean Partnership and local municipalities. The results from this ongoing study are presented in the dashboard below and will be updated regularly.

CDPHE Post Marshall Fire Surface Water Monitoring Efforts

Wells

Potable water in the rural areas of unincorporated Boulder County often originates from a private well. Ensuring well water has been accurately tested for contaminates after the Marshall Fire remains critically important for homeowner safety and the broader community’s public health.

You may have a higher risk of drinking water contamination if you share a well with destroyed homes that are not properly disconnected. Please contact BCPH for questions regarding your shared well.

Assessing Well Damage

Flowchart – Assessing the Damage to Private Wells After a Fire

As a first step, visually inspect the wellhead and other components of the water system for damage, including melted wiring for pumps and the wellhead. If the wellhead has been damaged, temporarily cover the well to prevent contaminants from entering.

The Colorado Division of Water Resources has provided guidance on assessing well damage and actions to prevent groundwater contamination.

A water system damage inspection should include the:

  • wellhead or well house
  • well casing, cap or seal
  • above ground piping or structures
  • spring box
  • pressure tanks
  • filters or water treatment system
  • wiring or electrical components

Questions to consider:

  • What is the condition of the storage tanks, vents, or overflow pipes?
  • Is there standing water in the tanks?
  • Is there any evidence of melted plastic components?
  • Is there any evidence of pressure loss in the system? One way to check this is to turn on an exterior faucet to see if there is water flowing or you hear air escaping from the system.
  • Is there any ash or wildfire debris near the water system?
  • Does it seem like any ash, soot, or debris has entered any part of the water system?
  • Do you notice any other damage related to the fire?

Permit Requirements for Well Repair

Discuss permits with your well service provider or contact the Colorado Division of Water Resources

The Colorado Division of Water Resources provides general information on well permitting and an up-to-date list of well service providers.

Testing Well Water

IMPORTANT: If you notice unusual tastes or odors in your water – do not drink the water – get your water tested.

BCPH recommends having well water tested if your property was impacted by the Marshall fire or damaged by smoke. Contact your well service provider to determine if they can provide onsite or at-home testing.

Well water impacted by the Marshall fire should be tested for the following contaminants:

  • Volatile organic compounds or VOCs such as benzene, ethylbenzene, toluene, xylenes (BTEX); acetone, chlorobenzene, ethyl-tert-butyl ether (ETBE), methylene chloride, methyl ethyl ketone (MEK), methyl-tert-butyl ether (MTBE), naphthalene, styrene, tetrahydrofuran (THF), tert-butyl alcohol (TBA), and vinyl chloride monomer (VCM) using US EPA Method 524.2. Laboratories should also examine the water for other chemicals listed in the method.
  • Semi-volatile organic compounds or SVOCs using SW-845, US EPA Method 8270E.
  • Turbidity, pH, conductivity, color, nitrate, coliform bacteria.
  • Heavy metals such as lead, arsenic, copper, zinc, iron, and others may also be considered.

Purdue University conducted a small sampling study of water wells in the Marshall Fire burn area. Lithium and vanadium were discovered in some of the affected wells. Both of these elements are naturally occurring in Colorado groundwater, and it is unknown if these levels were elevated before the Marshall fire. Lithium or vanadium are not regulated in drinking water, but health-based screening levels have been established. If you are concerned about contaminants in your drinking water, we recommend testing your well water.

Collecting a Sample for Testing

IMPORTANT: Avoid drawing the potentially contaminated water into the building until you are certain it is not contaminated. If contamination is present, use of the water may contaminate plumbing.

Contact a well service provider, water testing lab or environmental consultant for guidance on sample collection.

Consider collecting water samples that are representative of both the well and water supply line that conveys water to the building.

Allow water to stagnate for 72 hours prior to sampling to capture potential contaminants in the water and system infrastructure.

Laboratories that test for VOCs, SVOC, and Heavy Metals

Colorado Analytical Laboratory
303-659-2313

This lab is unable to accept water samples directly from homeowners. However, your well service provider may be able to collect and submit a sample on your behalf.

This lab is certified by the State of Colorado to test for VOCs, SVOCs, and trace metals in drinking water.

Eurofins Microbiology Laboratories
720-758-6010

This lab is unable to accept water samples directly from homeowners. However, your well service provider may be able to collect and submit a sample on your behalf.

This lab is certified by the State of Colorado to test for VOCs, SVOCs, and trace metals in drinking water.

ALS Environmental
970-490-1511

This laboratory reports that they accept samples directly from homeowners.

This lab is certified by the State of Colorado to test for radiochemistry and trace metals in drinking water and can test for VOCs and SVOCs. However, they have not obtained the State’s Drinking Water testing certification for these analytes.

National Testing Laboratories
800-458-3330

This laboratory reports that they accept samples directly from homeowners.

This lab is certified by the State of Colorado to test for VOCs, SVOCs, and trace metals in drinking water.

Colorado Department of Public Health and Environment (CDPHE) water testing laboratory
303-692-3048

Protecting Groundwater

If your home has been destroyed, BCPH recommends that you consider disconnecting your well from your structure early in the recovery process to prevent the backflow of contaminants into the well and to replace or repair any damaged components or service lines.

IMPORTANT: Avoid drawing the potentially contaminated water into the building until you are certain it is not contaminated. If contamination is present, use of the water may contaminate plumbing.

The Colorado Division of Water Resources provides guidance on how to protect groundwater in a fire-damaged well.

Home Water Filtration Systems

BCPH recommends having well water tested prior to purchasing a home water treatment system to determine the extent of the contamination. The type and concentration of chemicals present may impact the effectiveness of a home filtration system.

Resources for Well Owners

Guidance on positive water test results and the use of contaminated water

Colorado Department of Public Health and Environment’s ToxCall

Onsite Wastewater Treatment Systems (Septic)

Guidance for Safe Gardening

Residents whose properties have been affected by the Marshall fire should take extra steps to stay healthy when gardening this spring and has created a flowchart to help assess potential risk.

Assessing the Safety of your Garden After a Fire – flowchart

Smoke, ash and soot from urban fires, like the Marshall fire, that burned structures, vehicles, everyday household products, plastic, rubber and automotive components can produce unhealthy particles and harmful contaminants, such as heavy metals, which can settle in soil and create unsafe conditions for gardens.

If there is ash on your property as the result of a burning structure, or if you have a thick layer of ash because you were close to the fire, there may be hazardous chemicals that require special handling. In this circumstance, BCPH recommends working with an environmental restoration service to remediate the property safely. Removing a significant amount of soil may require water misting to suppress dust and contaminated soil must be disposed of at an approved site.

If you have soil or lawn clippings that may be contaminated with ash in your garden or lawn:

  • Wear an N95 mask and gloves when moving or disturbing soil that may contain ash or soot.
    o Anyone with respiratory illnesses is advised to talk with their health care provider about what they can do to stay safe and whether they should wear an N95 mask.
  • Use a shovel or hoe to scrape and collect surface soil.
  • Try to minimize the amount of soil and dirt that is dispersed in the air.
  • Dispose of soil and lawn clippings via your regular trash disposal.
  • Take off your shoes before going inside and immediately remove and wash clothes in a washing machine.
  • Wash your body thoroughly.

BCPH recommends that residents:

  • Do not use a leaf blower or fan to clean ash, grass clippings or soil.
  • Do not use a broom or sweep hard surfaces.
  • Do not wash potentially contaminated soils into a storm drain. Instead, direct any water to a grassy area.
  • Do not compost potentially contaminated soil and grass clippings.

Ways to stay safe when gardening in fire-affected areas:

  • Keep your soil covered with wood chips or other landscape mulch to reduce airborne dust.
  • Use drip irrigation to prevent splash on growing vegetables.
  • Promote good drainage to avoid water pooling and prevent the concentration of contaminants.

Soil Quality

Testing results in the Marshall fire burn areas do not indicate that the amount of metals and asbestos in the soil poses a significant health risk and are consistent with locations not impacted by the fire.

Two of the 26 properties tested returned results above normal levels, but it is believed the Marshall fire did not cause the elevated levels. In addition, tests did not detect asbestos at any locations.

As a result of these findings, BCPH recommends that testing requirements for private debris removal permits be reduced from testing for 17 metals and asbestos to eight metals, including arsenic, barium, cadmium, chromium, lead, mercury, selenium and silver.

This altered recommendation will continue to provide safeguards for public health while also reducing the financial burden of soil testing on homeowners. BCPH will continue to evaluate recommendations based on additional test results.

Two of the 26 properties tested returned results above normal levels, but it is believed the Marshall fire did not cause the elevated levels. In addition, tests did not detect asbestos at any locations.

As a result of these findings, BCPH recommends that testing requirements for private debris removal permits be reduced from testing for 17 metals and asbestos to eight metals, including arsenic, barium, cadmium, chromium, lead, mercury, selenium and silver.

This altered recommendation will continue to provide safeguards for public health while also reducing the financial burden of soil testing on homeowners. BCPH will continue to evaluate recommendations based on additional test results.

Learn More

Residents who have questions or concerns about the impacts of the Marshall Fire, and subsequent recovery effort, can get more information here: