Frequently Asked Questions

Implosion is a safe and effective means of razing a structure via the use of explosives on pre-determined structural members. This demolition technique has been successfully utilized for the last half century.
There are several steps to performing an implosion:
1. Key structural supports are identified and exposed by removing interior, non-load bearing walls and piping. This process will take several weeks to complete.
2. Small diameter holes will be drilled at specific locations to act as explosive receptacles. Explosives are then placed inside the structural members, equipped with internal non-electric timing devices that will fire on queue. Once these ‘charges’ have been placed they will be covered to prevent fly of debris.
3. Final wiring will not take place until the morning of the implosion. Both towers will be imploded simultaneously and the implosion will cause the interior structure of each tower to rotate outward and away from the Commons food service facility. One tower will collapse to the east and the other to the west.

A Demolition Feasibility Study was conducted that indicated implosion demolition provided two advantages over conventional demolition methods - lower cost and less disruption to neighboring areas.

The implosion demolition industry has a successful record of bringing buildings down in close proximity to other structures. In many projects, the buildings demolished are located very close to structures, which are to remain. In our project, we are in excess of 200-feet from the closest privately owned structure, which provides ample distance to reduce the risk of damage to adjacent properties. The closest structure is the University owned Storms/Knapp Commons building operated by Dining Services.

Similar Project Example:
Eliot Residence Hall, Washington University, St. Louis, MO
13-story residence hall, imploded in June 2003.
The University demolished an identical residence hall building earlier using wrecking ball demolition, which took 3 months. They subsequently switched demolition methods to implosion for the Eliot Hall demolition. Private homes were located directly across from the project site about 200-feet from Eliot Hall. An adjacent University building located approx. 40-foot away remained in place.

Peterson Contractors Inc., Reinbeck, IA
and
Controlled Demolition Inc., Phoenix, MD

The most noticeable effect in a residential area adjacent to a building demolition location is dust. Dust is an unpreventable byproduct of all types of demolition. Depending on wind speed and direction on the day of the implosion, the dust may or may not reach your properties.  PCI has been removing the majority of dust producing elements from the building (i.e. drywall, plaster, ceramic tile, etc.) in preparation of the implosion so we can reduce dust generation as much as possible.

In our planning, design, and construction phases of this project safety for everyone involved with the project including the neighborhood residents and the properties, University owned structures, and the construction workers is our #1 priority. Only the 36 properties located within 300 feet of the Towers property line will need to be vacated. This area is designated as an Exclusion Zone. Residents will be asked to vacate homes in this zone by 8:00 am on the morning of the implosion event. After the implosion, residents located in these properties will be able to return to their homes or apartments as soon as the utility companies have completed their inspections, the City of Ames has determined that any unsafe conditions have been removed, and the streets and sidewalks have been adequately cleaned. This total time period could be as short as 2-1/2 hours but should not be more than 6 hours after the implosion. We will work to reopen the area as soon as possible after the demolition so you can return to your homes.

We anticipate everyone returning to their homes the day of the implosion.

No. The closest home is located over two hundred feet from the nearest portion of the Towers buildings to be imploded. In many implosions, it is common for adjacent properties and streets to be located only 10 to 20 feet from the structure being imploded. The majority of implosions occur in major metropolitan areas with other structures in relatively close proximity and are completed successfully without damage.

Videotaping of properties immediately adjacent to the project site will be made by our documentation specialist. The demolition contractor will also make their own recordings for their documentation. The videotaping will record the visible condition of the property, structures, trees and plantings, and any site improvements. We anticipate the video recording to be done for properties along Hayward Avenue, Storms Street, and Welch Road that are adjacent to the north end of the project site. Videotaping will be done from the sidewalk or street.  Peterson Construction Inc. may be contacting home and property owners in those buildings immediately adjacent to the site for additional documentation of the properties. 

We do not anticipate a homeowner needing to make such documentation but would encourage property owners to make whatever documentation they desire of their property and structures.

If you live in the Exclusion Zone and you have an pet that you are uncomfortable leaving in your home during the implosion, please contact Kerry Dixon-Fox, 294-1016, and accommodations will be provided for the pet.

If you live in the Exclusion Zone and need assistance please contact Kerry Dixon-Fox, 294-1016, and accommodations will be made.

General liability insurance to cover any unexpected damages that occur as a result of the demolition activities will be carried by the contractor under the terms of the contract with the university. We would not expect any special arrangements to be necessary with respect to your homeowners insurance coverage but we would encourage you to speak with your insurance professional if you have concerns.

The goal of our planning for this project is to avoid any unintended damages and we do not expect to have any. We will be monitoring the demolition very closely and measuring vibration levels for comparison against recognized standards. The University and its contractors have an obligation to exercise reasonable care to avoid harm to others. In the event that you feel that damage to your property may have occurred, you may have a valid legal claim. Contact numbers will be made available for you to report this damage. Damage reports will be investigated and resolved. The State of Iowa has a statutory process for filing claims against the State. It is a common practice in this industry to require the contractor to provide insurance as part of his insurance program to provide coverage for the owner of a project ( in this case ISU) and we require our contractors to have adequate insurance to cover such events.

Yes, Knapp and Storms Halls are constructed of reinforced concrete, as are a majority of structures razed by implosion. Each Tower is equivalent to a twelve-story building, which is considered shorter than average as it relates to implosion.

The actual implosion will occur in less than 60 seconds. Prior to the implosion, on-site preparation operations will take several weeks to complete. Explosives will not be brought onto the site until 72 to 84 hours prior to the event, at which time the ISU Department of Public Safety and City of Ames Police Department will provide site security.  Inspections of the site will be done by the Iowa Fire Marshal's Office and the Bureau of Alcohol, Tobacco and Firearms.

Weather is typically not a concern for implosions unless it is severely adverse such as a tornado, severe thunderstorm, high winds, or low cloud cover.

No more dust will be created by implosion than would be by conventional demolition (crane/wrecking ball). The advantage to implosion is that the dust will be created during one specific short-term event. Therefore, appropriate precautions, such as covering heating and cooling systems and closing doors/windows, can be employed to protect surrounding areas from dust. If the two Towers were demolished conventionally, the process would take much longer to perform and these precautions would not be feasible for that extended period of time. In this implosion dust will be minimal because the building materials that are known to create excessive dust (furniture, masonry, plaster, drywall, wood) will be largely removed prior to implosion. Dust may linger in the immediate area for 5 to 10 minutes following the implosion. The extent the dust will travel depends on weather conditions and wind speed. Given the large vacant area surrounding the Towers, the majority of the dust will remain on the site.

Materials that could be classified as hazardous if they became airborne in sufficient quantities are present in many common building materials. Concentrations of these hazardous materials are very low. Hazardous materials that may exist in the dust cloud should be far below concentrations of concern. Some asbestos containing building materials (ACBMs) were used in the construction of these buildings. As required by law, the facility was inspected by state licensed personnel to identify ACBMs and work is ongoing to properly remove these materials from the building. This work is being performed by a state licensed contractor and will be completed prior to the building demolition. After completion, the building will again be inspected by licensed inspectors to ensure complete removal of ACBMs.

An independent third-party engineering consultant that specializes in air monitoring will measure air quality levels on the day of the event before, during and after the implosion. These values will be compared to applicable standards such as the EPA National Ambient Air Quality Standards to assure that levels remained below those considered hazardous.

Close all windows and doors prior to implosion to prevent dust infiltration. If you have windows or doors that are broken or do not seal properly, you can use a towel or tape to fill all air gaps. Close outside air intakes and exhaust fans until the dust has been cleaned up. Since the implosion will be performed during a time of the year when air conditioning is traditionally utilized it will be necessary to turn off these units. We anticipate this will take six or fewer hours on the day of the implosion. This warning is very important for small children and people with respiratory health issues.

There should be little to no effect upon plants/landscaping. According to ISU Extension Horticulturists the primary components of concrete (calcium, silicon, iron, and aluminum) are either fertilizing compounds in the case of calcium and iron, or will have no effect upon plants. You may want to simply hose off any foliage but the first rain will eliminate any residue on the foliage.

The dust clean-up time depends on weather conditions at the time of the implosion. After workmen have been cleared to enter the area, dust clean up will. Adequate crews and equipment will be on site to immediately implement this process. The outermost perimeters will be cleaned first working inward to the areas that experienced the largest concentration of dust. This is done so that the largest portion of streets and residents can return to normal activities as soon as possible. In any case, we do not expect this exceed six hours.

The implosion will be designed to minimize the amount of vibration. You may experience a slight vibration, but no damage to property is expected. The physical feeling of the vibration is difficult to quantify due to the uniqueness of each project site, soil conditions, and proximity to adjacent structures. Some describe the feeling is similar to standing next to a fast moving train or a city bus. We anticipate the debris impact will cause little or no vibration to your home. An independent third-party engineering consultant that specializes in seismic monitoring will measure ground vibration levels on the day of the event to verify the implosion went as planned. These values will be compared to the U.S. Bureau of Mines vibration criteria for residential structures.

We would suggest a cautious approach and would suggest you to remove any items that are particularly sensitive to vibration or that you are concerned about.

Implosions are commonly performed with utilities present directly below the structure being razed without damage. Given the location and depth of the utilities surrounding the Towers, no damage or precautionary outages will occur outside of university property.

A pile of rubble approximately 40 feet tall will remain for each Tower and contained within the site fence. The demolition contractor will immediately begin to remove the resulting debris. This process will continue for approximately 5 weeks.

The majority of the demolition debris will be waste concrete, which the University intends to retain and store for later crushing into aggregate (gravel) to be used for base material in new driveways, parking lots, and sidewalks. The remaining demolition debris will be the property of the contractor who will typically recycle eligible materials, and then landfill the remaining debris.

The site will be returned to green space with hydro-seeding of grass, tree replacement, and sidewalk replacement to provide access to the Knapp-Storms Commons food service facility.

While we do not encourage spectators at the implosion, we know it is inevitable that some people will want to view the event in person.  The public will be allowed to view the implosion a safe distance away from the site - either to the east or west of the Towers, depending on weather conditions an dwind.  Stay tuned to local media and check the ISU webs site (www.iastate.edu) for updates as the implosion date nears.  Parking will not be provided for those wishing to view the event. Parking will be available at the Iowa State Center lots.

On the morning of the event, streets in the Campustown area will be restricted.  Hayward Avenue will be closed between Mortensen Road and Knapp Street; Welch Avenue will be closed South of Knapp Street; Stanton Avenue will be closed South of Baker Street; Lynn Avenue will be closed South of Baker; and Storm and Donald Streets will be closed West of Ash Avenue.