Legible version of the subway monitoring plan surfaces, shows arena wall less than 7' from subway; if vibrations get too intense, work must stop

How do you build an arena very close to six active subway lines?

Very, very carefully, apparently.

As a recently acquired document (excerpted at left; click to enlarge) shows, the foundation wall of the planned arena, at at the arena property line, would be less than seven feet from the wall of the IRT subway line, specifically the tracks for the 2 or 3 trains going north along Flatbush Avenue toward Manhattan.

That means some very careful monitoring is required, as described in plans first made public here.

Plans initially denied

On May 24, I wrote about a Subway Indemnity Agreement signed by Brooklyn Arena LLC and the New York City Transit Authority, not only must proceed "in a good and workmanlike manner" but also must be subject to a monitoring plan, thus protecting critical transit system assets.

That's crucial, because portions of subway tunnels next to the arena site were described in 2007 as in "critical condition" and required repair "in the immediate future" and the "near future"--repairs Forest City Ratner is now obligated to make, though the cost is unclear (and could generate a request for future public support).

But the plan, at least as reproduced in the document, was illegible.
And, when I filed a Freedom of Information Law request for a legible copy, I was told no such copy exists.

Airing a complaint

So I wrote about that absurd situation and, a few weeks later, unbidden, I received a package from the Metropolitan Transportation Authority (MTA), which contained hard copies of the documents at issue: four huge blueprint-style documents, about 44" by 36".

Three are reproduced below, thanks to high-resolution photography by Jonathan Barkey. (The fourth page included general MTA instructions.)

Click on the MTA Arena Monitoring Plan to get the get the most legible versions, capable of magnification.

What it means

But what's in the monitoring plan?

I'm hardly an expert on such work, so perhaps others will take a close look, but here's a summary.

Drawing M-1, the overview, points to the area, at the left of the document, where work and monitoring will take place, near the tunnels housing the B/Q and the 2/3/4/5 lines.

The notes at the bottom left of the document, reproduced at right (click to enlarge), refer to Mass Transit Improvement Drawings dated 10/23/09, which I have not seen. Subway monitoring, to be performed by a monitoring agency retained by the developer, involves seismographs and tiltmeters with remote meters, the installation of which may require closure of adjacent tracks.

The work involves monitoring of vibrations continuously during demolition, pile drilling, excavation and placing compacted backfill within 50 feet of the subway.

If vibration limits are exceeded, the contractor "shall modify pile installation or excavation procedures as required." Work must stop if the subway movement reaches 1/4".

First drawing: the overview

From MTA Arena Monitoring Plan

Second drawing: proximity underground

The second document shows the proximity of the arena structure, the two subway tunnels, monitoring points, and a proposed vent structure--likely the upgrades to the MTA vent structures now under construction.

From MTA Arena Monitoring Plan

Third drawing: another view of proximity

This document shows that the arena foundation wall would be 6' 8.5" from the subway wall.

From MTA Arena Monitoring Plan

Advisory opinion

After my first FOIL request was denied, but before I received that unbidden package of documents, I wrote to the state Committee On Open Government (COOG).

Earlier this month, I got an advisory opinion from the COOG :

We are in receipt of your request for an advisory opinion regarding the application of the Freedom of Information Law to a request made to the Metropolitan Transit Authority. Specifically, you requested a legible copy of a six page report within a subway indemnity agreement that you found on this agency’s website. You were informed that no legible copy existed and that the copy you obtained on the website was the only one that existed.

In this regard, when an agency indicates that it does not maintain or cannot locate a record, an applicant for the record may seek a certification to that effect. Section 89(3)(a) of the Freedom of Information Law provides in part that, in such a situation, on request, an agency "shall certify that it does not have possession of such record or that such record cannot be found after diligent search." It is emphasized that when a certification is requested, an agency "shall" prepare the certification; it is obliged to do so. If you consider it worthwhile to do so, you might request a written certification in accordance with § 89 (3)(a).

COOG MTA Letter July 12, 2010