Ash Removal


Each community or public agency organizes an ash cleanup operation in its own way using the available machinery and equipment and sometimes, the help of people and organizations not affected by the ashfall. By sharing the experiences of those who had to remove and dispose of volcanic ash, communities who are affected in the future can avoid some of the hardships experienced and mistakes made. No one technique is likely to be the best in all situations and a range of measures often provides the best results. Constant monitoring of ash effects and mitigation procedures is encouraged to achieve the most effective balance between operational requirements and damage limitation.

Mt. St. Helens, 18 May 1980; Yakima, Washington

Lessons learned (from Joe Jackson, City of Yakima, in Johnston & Becker, 2001):
  1. Don't panic or rush into the clean-up operation without thinking it through.
  2. Have a good arrangement with contractors prior to a disaster so you know you can count on them when they are needed.
  3. Develop a plan for the systematic clean-up of the city so those involved know what they have to do. Pre-planning can save a community a lot of problems.
  4. The finer the ash the more problems you will have.
  5. Keep good records, especially all financial documentation. A special emergency cost accounting system for audit verification of all ash clean-up expenses is recommended.
  6. Maintain daily briefings with the press/media to inform the public, establish trust and their cooperation in informing citizens. Involve all emergency agencies in joint announcement briefings.

Mt. St. Helens, 18 May 1980; Spokane, Washington

Scott Egger, Director of the Street Department in the city of Spokane, Washington learned that damp sawdust helps to bind fine ash for street-sweeping.

In 1980 when Mt. St Helens erupted, Spokane had over 850 mi (1400 km) of paved roadways that required ash removal. The ash that fell in Spokane was so fine that it could not be picked up with conventional equipment and went airborne when it came in contact with street sweepers. Cities and towns located closer to Mt. St Helens were able to use graders and sweepers because the material was not as fine as the ash that fell in Spokane. Placing only water on the ash did not help, so the city experimented with different materials placed on the streets that would bind to the ash and make it easier and more efficient to pick-up. The street crews found that damp sawdust served as a good binder. Crews applied damp sawdust on city streets with sanders. The damp sawdust and ash were then swept-up with conventional street sweepers.