Case Study: Bolander Stomps Out Dust At Minneapolis Grand Hotel Demolition

Company President Mark Ryan said he sees ownership of the DB-60 as a competitive advantage that helps differentiate his firm.

Although the sensitive location between the Mall of America and the Minneapolis Airport could have presented significant dust headaches for Bolander and Sons, the firm was able to complete its takedown of the 17-story Grand Hotel in Minneapolis, Minnesota (US) without a single dust-related complaint.

The size and location of the demolition site caused some initial concerns about dust management, and engineers knew that traditional methods such as manual spraying would not be adequate for such a project.

During the search for more advanced technology, they witnessed a demonstration at the jobsite of the DustBoss DB-60. Bolander was convinced to lease the unit for the entire year-long project by its ability to deliver a dust-trapping mist all the way to the top of the 175-foot structure.

Hoses and sprinklers typically can’t create water droplets smaller than about 300 microns. When the drops are that large, they create an impact upon landing that actually mobilizes stationary dust. And they are almost completely ineffective against airborne particles.

“This is the best dust controller that I have ever seen.”

- Eric Sundbo
Environmental Scientist, Liesch Companies

Instead, the DustBoss is designed specifically for large-scale suppression, with 50–200 micron droplets launched by a powerful 25 HP fan, allowing the oscillating DB-60 to cover nearly half a football field with a dust blanket.

The greatest attraction between dust particles and water droplets occurs when they are about the same size and that is why the nozzles are designed to create a specific size range of water droplets.

The effects of the dust suppression were immediately apparent and crews also noticed that the technique required less water than hand spraying, reducing the saturation and weight of the debris to be hauled away.

Representing the Metropolitan Airport Commission, the Liesch Companies served as consultants on the project. Environmental Scientist Eric Sundbo said, “This is the best dust controller that I have ever seen.”

In fact, demolition personnel and site supervisors were so satisfied with the results that Bolander and Sons decided to purchase the unit when the project was complete. Company President Mark Ryan said he sees ownership of the DB-60 as a competitive advantage that helps differentiate his firm.

CUSTOMER
Carl Bolander & Sons Co.

LOCATION
St. Paul, MN

CHALLENGE
Suppress dust from the demolition of a 17-story building situated between the Mall of America and the Minneapolis Airport, preventing a nuisance or safety issues from affecting customers or travelers. Attempting to control surface dust and airborne particles with a fire hose was deemed insufficient, prompting the search for a more effective method.

SOLUTION
The DustBoss DB-60 a powerful dust suppression unit launching water particles 200 feet or more and oscillates to cover nearly half an acre (about .2 hectares) with its fine, dust-trapping mist.

RESULTS
Bolander & Sons leased the DB-60 for the entire year-long demolition project, helping to prevent dust migration that could have affected visibility, airport equipment operation or local businesses. The unit was so effective that the firm did not receive a single fugitive dust complaint, and company officials decided to purchase the unit when the job was completed.

CARL BOLANDER & SONS has been delivering safe and efficient demolition services for customers throughout the United States since the 1940s. Incorporated in 1924 as a grading and excavating specialist, the firm has grown to become one of the most capable and versatile providers in the demolition industry. The company takes pride in offering customers a complete site package, with a well-trained work force, experienced project management team and state of the art equipment.