Upper Dublin News Release: Proposed Blasting at St. Mary’s/Mattison Estate

Today, Upper Dublin sent the following News Release regarding the proposed blasting at St. Mary’s/Mattison Estates:


Proposed Blasting at St. Mary’s/Mattison Estate



(Upper Dublin Township, PA – March 27, 2019) Upper Dublin Township released answers to several questions that arose after a letter from AMROC was sent to residents regarding the proposed blasting at St. Mary’s/Mattison Estate:

1. The blaster’s letter contains required language that is prescribed by the State Department of Environmental Protection (DEP). Although the blaster does not anticipate the intensity of blasting that the letter portrays, they are required to inform residents within 1,000 feet of the potential blasting about the timeline, schedule, gases, noise, vibrations, etc. The letter is a state-mandated letter, which cannot be altered.

2. The blasting is likely to occur once or twice a day, usually in the afternoon, on a good-weather days. Although the blast notice indicates the blaster may blast from sunrise to sunset, the Township does not anticipate that level of activity. A daily procedure involves drilling holes in the ground during the morning, placement of blast material mid-day, then a detonation of the material in the afternoon, and finally removal of the blasted material by backhoe towards the end of the day.

3. Residents within 1,000 feet may feel a small vibration, similar to foot stomping or the vibration caused by a slammed door, for about 1-2 seconds. It would be more noticeable on the second floor than it would be on the first floor. The blast intensity should be far below any vibration that would cause damage to a dwelling, be it a foundation, pictures on the wall, china in a cabinet, etc.

4. The blaster (AMROC)’s telephone number is on the letter. They will take phone calls and try to answer questions. AMROC will send letters to all properties within 500 feet of the proposed blast area regarding a pre-blast survey. Residents can have dwellings surveyed, if there is a concern about damage that may be caused by the blasting.

5. The blasting could be delayed by a few days from the April 8th start date listed in the letter.

6. The sirens/horns are similar to the fire company horns from Upper Dublin or Ambler, but they will sound as indicated in the letter (three times before, and a short and long horn after). The horns are produced by a small can of compressed air (the size of a soda can) with a trumpet on the end. The horn lasts about 4-5 seconds.

7. The “blasting” expected during these development projects takes place below the ground. The blast is done to loosen the rock at the blast point, several feet below the ground. The soil above the blast point serves as a blanket to protect the above-ground surface from flying rock or dust. You will not see rock flying high into the air. These types of blasts are controlled so that the ground will only “fluff” or rise minimally (1’-2’) above normal grade. 

8. There is no evacuation anticipated or required for this type of blasting.

9. The blaster is aware of the sensitivity of the castle foundation and has tempered the blast intensity to not disturb its foundation. Since the castle is several hundred feet closer to the potential blast site than any other dwelling in the area, we anticipate a significant reduction of vibration effects at dwellings in the area.

For more information, contact Tom Fountain, Township Engineer, attfountain@upperdublin.net or (215) 643-1600 ext. 3372.