Present were Blasting Technical Supervisor Ken Smith and Project Manager Andy Dufore, as well as Westwood Deputy Fire Chief Mike Reardon.
"Tonight's presentation is really a Blasting 101...The purpose of this whole presentation was to demystify the science of blasting," said Smith as he started the evening with a 30-minute presentation which the audience of home and business owners seemed to appreciate.
Smith, who lives in Hopkinton, has blasted for 38 years and followed in the footsteps of his grandfather who blasted for 50 years. He told the audience about many comparable projects his company has completed, including hospitals and office buildings.
Deputy Chief Reardon alerted the audience of about 12 (from neighboring Partridge Drive, Whitewood Road, and nearby businesses) that blasting in the same area by the same company in 2007 went fairly well. An abutter in attendance agreed.
"You have already got the face off some of this so for all intents and purposes it's actually aimed toward the railroad tracks," said Reardon, who likened the blasts to living beside the railroad tracks and suggested the abutters will likely not notice the blasts after the first couple weeks.
Highlights of the presentation included:
- Blasting will start later this month (August) then run into January or February
- Will run Monday through Friday from 8 a.m. to 4 p.m.
- Actual blasts last about 30 seconds
- There will likely be just one blast per day (the majority of the day is spent trying prepare the site
- Abutters can sign up to be notified when the company will blast
- Abutting residents and businesses should have had a pre-blasting survey taken. So far, 43 properties have been surveyed.
- Any property damage should be reported by a form available at the fire station; the matter is then turned over to the Fire Marshall, if need be.
- One couple was very concerned a blast would damage their in-ground pool. Smith said that wouldn't happen and the power needed to crack a concrete pool foundation would "devastate" a house's interior walls.
- The loud boat horn will be used to alert the site and neighbors. Deputy Chief Reardon said the horn will likely be more annoying than the blast itself. The horn will sound three blasts at five minutes before the blast, two blasts at one minute before the blast, and a single tone as an "all clear" after the event.
- Residents will likely feel some of the effects of the blasting on some days and not on others (depending on the wind and other factors)
- After a few weeks, the blasts will start to just sound familiar and it may not bother
- Cell phones will be allowed; they were outlawed in the past but that is no longer the case
- Traffic should not be impacted by the blasts
- The time for an actual blast is less than a second
"Nothing is supposed to leave that blast site at all; if it does, we have a problem," said Reardon.
The effects of blasting are essentially (1) ground vibration and (2) air overpressure/blast.
A Hemlock Street resident said she remembers when NSTAR blasted in 2007, and "it was rumbling and vibration" and "no big deal." However, she said, the University Station project looks like more work.
The company proposes to start at the lowest point of the site (lower right corner on the attached shades-of-red map) where they will blast two to five feet -- a sort of "test blast," and make their way up the hill where blasts will go down as much as 30 feet.
Want to know more? Visit www.mdandb.com to view "History of Rock Blasting," "Anatomy of a Blast," and more.
The presentation will be available on Westwood Cable Access Television after Aug. 17.