Blasting usually is required on construction sites for the installation of sanitary sewer lines which are placed fairly deep and often below bedrock.
Only skilled and experienced personnel who are licensed by the state are allowed to blast. They must notify adjoining property owners within 500 feet when and where blasting will occur and offer to do a pre-blast survey.
Before a permit is issued by the Fire Department, the following is required:
- File for a Blasting, Explosive Storage & Transportation permit online.
- Provide a scale drawing or aerial photo is required showing:
- Surrounding Land
- Improvements on Land
- Occupied housing and buildings adjacent to and their relationship with side of blasting.
- Occupied housing and buildings adjacent to and their relationship with storage facility.
- Type of construction; shows extent of blasting operation.
- Certificate of Liability Insurance (Amount to be approved by City Engineer)
- Land disturbance permits
- Pre-blast survey is an inspection, usually photographed or videotaped, that documents conditions within 500 feet of the blasting site before blasting is done. These inspections generally are prescribed by a contractor's insurance carrier; however, the homeowner has the right to refuse the survey.
- How blasting is monitored:
Seismographs must be placed on the site to monitor vibration levels. A seismograph typically is placed on the property line at the closest home or structure. The maximum peak particle velocity at any such recording site must not exceed one inch per second. The standard was set because it is one half of the level set by the federal government as being safe for frame houses. Although people start feeling blasts at .05 inches per second, a structure can withstand considerably higher levels.
Blasting can be done anywhere on an adjoining property as long as it is done in a manner that does not damage adjoining property, and seismograph readings do not exceed one inch per second.
Additionally, blasting operations must be carried out in such a manner that they will not cause fly rock or damage from air blast overpressure or ground vibration.
The blasting contractor must keep a daily blasting log for all blasting operations and make it available for inspection by the Fire Department. Fire inspectors also may make periodic inspections and check the seismograph records, but are not present at all blasting operations.
Frequently Asked Questions
Review the most frequently asked questions from homeowners regarding blasting.