Blasting Starts Wednesday at 8300 Wisconsin Ave., Bethesda

Construction crews have reached bedrock at 8300 Wisconsin Ave., Bethesda, and now it's time to blast it away.

Starting Wednesday, there'll be about one blast a day at the site at the northwest corner of Wisconsin Avenue and Battery Lane, where a mixed-use development with a Harris Teeter grocery store is to be built, according to signs around the property. Blasts will be preceded by a series of horn alerts, according to an email message from the Montgomery County Office of Emergency Management and Homeland Security.

The blasts will occur between 10 a.m. and 2 p.m., will be coordinated with Metrorail service, and will be independently monitored, according to the county's office of emergency management.

Additionally, pedestrian traffic around the site will be halted for 5 minutes before blasting, and vehicular traffic will be paused for 1 minute before the blasts, according to the county's office of emergency management.

Before each blast, a horn will sound to indicate that a blast is impending. "The horn is predominantly a notification for the construction workers on the site. However, the horn is loud enough for individuals immediately adjacent to the site to hear," the county's office of emergency management added.

The horn signals will follow this pattern:

• A warning signal (a long horn) will sound about 15 minutes before a blast to signal that a blast is coming and to allow time for construction crews to move outside the immediate blast area.
• A second warning signal (a long horn) will sound 5 minutes before the blast.
• A blast signal (a series of short horn sounds) will sound 1 minute before the blast.
• The all clear signal (a prolonged horn) will sound following the inspection of the blast area, indicating to the construction workers that they may return to work.