Tuesday, November 22, 2011

"Cease Blasting" Order Issued... then Lifted

Updated on 11/23, 11/28, 12/2 and 12/7/11

The MTA announced this evening that a "Cease Blasting" order has been issued at the Second Avenue subway 72nd Street station cavern site. The announcement was made at this evening's Community Board 8 Second Avenue Subway Task Force meeting by William Goodrich, Program Executive for MTA Capital Construction.

The MTA order, which went into effect after the last blast today, will remain in effect until Monday, December 5th.

The MTA said that, during this period, it would work with its contractors to implement additional measures to control the dust, smoke and odors that are produced during blasting operations at the site. The smoke and odors in particular are the combustion byproducts from the Emulex explosive material used in the blasting.

One source told me that as many as 200 workers may have to be temporarily laid off due to the suspension of blasting at the site.

The MTA's contractor at the site, SSK Constructors, had been using explosives to blast out the underground station cavern for the 72nd Street station. Many area residents at the Community Board meeting claimed that the voluminous amounts of dust, smoke and odors produced by the blasting were unhealthy.

The MTA has contracted with its consultant construction manager, Parsons Brinckerhoff (PB), to study the situation, and to verify that emissions from the work site do not have the potential to violate any health-based standards.

Here is a link to the report that was provided by the MTA last month to Community Board 8 in connection with this issue:

Preliminary Air Quality Results
Parsons Brinckerhoff

The MTA said tonight that PB's final report is expected to be released by the end of the year.

At the meeting, the MTA said that the cavern blasting is about 40% complete at the moment. They also indicated that they expect to finish the blasting for the 72nd Street station cavern roughly in the middle of 2012.

Further reports can be found on these links:

"M.T.A. Halts Blasting for 2nd Ave. Subway Around 72nd St."
The New York Times
By Christine Haughney and Michael M. Grynbaum

"Air Quality Worries Halt Subway Blasts"
The Wall Street Journal
By Jennifer Maloney and Andrew Grossman

"2 Views on Subway Project: Delay Work to Clear Air, or Carry On and Profit Sooner"
The New York Times
By Christine Haughney

Update 11/23/11

A reader provide me with these two images of what it can look like near the corner of 72nd Street & Second Avenue after a blast.

Courtesy of J. Puglisi
11/8/11 3:46 p.m.

Courtesy of J. Puglisi
11/15/11 4:19 p.m.

In this image you can see the dust and smoke from the blast being exhausted onto Second Avenue through the two large vents on the side of the muck house.

Update 11/23/11

These images, from another date, provide yet another post-blast view of the scene.

Courtesy of Steve Broer
11/7/11 5:14 p.m.

Smoke and dust being exhausted at street level on Second Avenue.

Courtesy of Steve Broer
11/7/11 5:11 p.m.

This image shows four people, who would appear to be unrelated, covering their mouths as they walk past the north end of the muck house after a blast. Clearly there was something in the air that each found to be objectionable.

It is unfortunate that the majority of blasting-related dust, smoke and odors cannot somehow be vented at a higher elevation instead of at street level as is being done now.

It's not for no reason that New York City's building code requires that chimneys, for example, extend 3, 10 or 30-feet [depending on the temperature of the chimney] above the highest construction, such as a roof ridge, parapet wall, or penthouse. (Ref. NYC Building Code, Title 27, §1501.4 - Chimney heights and locations.)

Update 12/2/11

The following letter, written by Michael Horodniceanu, the President of MTA Capital Construction, was broadcast via email to the Second Avenue community earlier today.

The email details the changes that the MTA has made to the site and to their blasting procedures in preparation for the resumption of blasting of the 72nd street station cavern on Monday, December 5th.


From: Wilson, Claudia
Sent: Friday, December 02, 2011 5:37 PM
Subject: Second Avenue Subway Information

Dear Neighbor,

It is my goal to provide you with the best possible relief while building the Second Avenue Subway. As you are aware, we recently suspended blasting the 72nd Street Station Cavern to provide enhanced containment of smoke and dust.

Since then, we’ve implemented changes and we will resume calibrated blasting starting Monday, December 5th.

On Monday, I will personally be on-site with Bill Goodrich, the Second Avenue Subway Program Executive, and his senior staff to ensure we are doing everything we say we are doing to minimize blast emissions.

Here’s what will be different starting on Monday:

Muck House Changes

1. The opening located in the overhang at the north end of each muck house has been permanently sealed. The purpose of this overhang was originally to allow the blast pressure to escape, however it resulted in an unacceptable amount of dust and smoke to leak out.

Since we still need to provide blast pressure relief, the doors to the muck house will remain open until blast pressure has passed (approximately 1 – 2 minutes) but will be closed immediately thereafter. (It takes several more minutes after a blast before the smoke rises out of the cavern shaft.)

2. Vent stacks have been installed on top of both muck houses. The purpose of the vent stack is to release smoke in a controlled manner from the top of the muck house after the remaining dust has settled within the muck house.

The vent stacks will be operated manually by a worker who will open it once the dust has settled.

Additional Dust Control Devices

1. We have purchased two additional Dust Bosses. A Dust Boss sprays a fine water mist into the air. The water saturates the air, adheres to dust particles, forcing dust particles to settle within the muck house. The use of water as a dust mitigation practice is one that is endorsed by both OSHA and the EPA.

We have also relocated Dust Bosses within the shaft bottom to more effectively control the emission. You can find more information on Dust Boss technology at http://dustboss.com/products.

2. We have also installed a wet burlap curtain that will act as screening device for dust at the bottom of the shaft.

I thank you for your patience as we continue to work on improving your quality of life during construction. I will keep you informed of any future changes.

Very truly yours,

Michael Horodniceanu
President, MTA Capital Construction


Update 12/7/11

Blasting resumed at the 72nd Street Station cavern site on Monday afternoon, December 5th.

I took a walk, with my camera, around this work site this past Saturday (12/3/11), and this is what I observed.

73rd Street, NE corner - looking S

One of the changes to the work site, to mitigate the effects of the blasting, can be seen in the image above and, even better, below.

The MTA's contractor at this location has now sealed the opening at the north end of each muck house. This was done in an effort to contains the dust, smoke and odor, from the blasting -- inside the structure.

The dust, smoke and odor would then be allowed to more slowly filter out onto the street.


A closer shot of the (now sealed) north end of the muck house between 72nd & 73rd Streets.

just south of 72nd Street - looking E

If you look carefully you can see a set of air monitoring equipment that has recently been set up on the fire escape of this building.

70th Street - looking N

And another set of air monitoring equipment has been set up on the veranda in front of the temporary contractor's offices.

btw. 69th & 70th streets - looking S

On this muck house, you can see that they have recently changed the orientation of the north vent stack. It now is pointing up, instead of sideways.

Most reports that I have read suggest that the "post blast air quality" on Second Avenue is now better that it was before the blasting was stopped. Frankly speaking, this should come as no surprise to anyone, as the blasts were smaller ones.

By all accounts, the blasting that took place on Monday was very limited -- since the MTA themselves said that they would resume blasting using a technique that they called "calibrated blasting" -- which I could imagine means that they will very carefully and slowly ramp up the blasting [again] so as to minimize the effects on the neighborhood.

Here are a few reports that were published on Monday when the blasting was resumed.

"Underground Blasting Resumes On Second Avenue Subway"
By Tina Redwine
Video (1:36) - NY1 - 12/5/11

"MTA Resumes Second Avenue Subway Blasting"
By Sonja Sharp and Amy Zimmer
DNAinfo.com - 12/5/11

Good Day New York, with Benjamin Kabak
Good Day New York
Video (3:19) - Fox 5 - 12/6/11
Transit Blogger Benjamin Kabak talks about the effects of the blasting on Second Avenue.


And here are a few other images from my walkabout this past Saturday.

69th Street, SE corner - looking W

The structure that formerly stood on the NW corner of this intersection is almost gone. It has been demolished to make room for the ancillary structure that will be built in its place.

69th Street, NW Corner - looking W

Remains of the building -- waiting to be carted away.

69th Street, just west of 2nd Avenue - looking NE

Another view of the demolition site.

69th Street - looking S

A nice view of the winter sun shining through the fence wrap at this location.

1 comment:

Sandblasting Contractor said...

One source told me that as many as 200 workers may have to be temporarily laid off due to the suspension of blasting at the site.