LETTER REGARDING NOTIFICATION OF EXCEEDANCE OF … · events do not show exceedances of the PCB notification level, GE will resume monthly PCB air monitoring in accordance with the

Transmitted via Electronic Mail and Overnight Delivery

May 8, 2013

Mr. Dave Dickerson U.S. Environmental Protection Agency 5 Post Office Square - Suite 1 00 Boston, MA 02109-3912

Re: GE-Pittsfield/Housatonic River Site Silver Lake Area (GECD600)

GE 159 Plastics Avenue Pittsfield. MA 01201 USA

Notification of Exceedance of Ambient Air PCB Notification and Action Levels and Proposed Responses

Dear Mr. Dickerson:

Pursuant to Section 10.1 of GE's Revised Scope of Work for Ambient Air PCB and Particulate Monitoring at Silver Lake Area (Appendix N to the Revised Final Removal Design/Removal Action Work Plan for Silver Lake Area), this letter provides written follow-up notification of an exceedance of the notification and action levels for PCB concentrations in ambient air at the Silver Lake Area, which occurred on May 2-3, 2013.

The results of the 24-hour PCB air monitoring event conducted on May 2-3, 2013 were received by GE in the afternoon of Sunday, May 5, 2013. These results are summarized in the attached table, and the locations of the monitoring stations sampled during that event are illustrated on the attached figure. These results show an exceedance of the PCB action level (0.1 11g/m3

) at Stations SL-1 and SL-4 as well as a co-located monitor (SL-4CO) and an exceedance of the PCB notification level (0.05 flg/m3

) at Station SL-3. The predominant wind direction on May 2, 2013 was from the west-southwest, and the three locations sampled during the May 2-3, 2013 monitoring event were in the vicinity of and generally downwind of the debris removal activities being performed during that time period, as well as downwind from a debris staging area located near the Fourth Street outfall. Sample locations associated with these exceedances are the same locations at which exceedances of the PCB notification and action levels had been observed in sampling conducted on April 24-25, 2013, as documented in a letter from GE to the U.S. Environmental Protection Agency (EPA) dated May 1, 2013 (although for that sampling event only one location, Station SL-3, exceeded the action level, and the other locations exceeded the notification level). It should be noted that there were no exceedances of the particulate matter notification level at any location.

First thing in the morning on Monday, May 6, GE provided verbal notice of the May 2-3 sampling results to EPA, as required, as well as to the Massachusetts Department of Environmental Protection (MDEP). In addition, on that date, GE did not conduct any excavation or debris removal activities. Late in the day on May 6, GE discussed the air monitoring results with EPA. Based on those discussions, on May 7 GE

C "rporate Em~1r:::nmentJI Proqroms

Dave Dickerson May 8, 2013

Page 2 of3

resumed bank excavation work in the southeast corner of the lake, as well as other non-intrusive work (i.e., other ongoing activities not related to debris removal).

Based on further discussions with EPA and MDEP, GE proposes to implement the following engineering controls and monitoring activities during the remainder of the debris removal operations:

• Continue with implementation of the engineering control measures described in GE's May 1, 2013 letter.

• Continue with daily 24-hour PCB air monitoring events (including, at a minimum, one on May 8-9, one on May 9-10, one on May 10-11, and one on May 13-14) until such time as debris removal operations are complete and PCB air levels have dropped below the notification level. If the data from any of these events show an exceedance of the PCB notification or action level, GE will report the results to EPA and MDEP upon receipt of the data and will follow the other steps specified in the Revised Scope of Work for air monitoring. Specifically, if the data show an exceedance of the notification level, GE will discuss with EPA appropriate additional activities to undertake based on those results; and if the data show an exceedance of the action level, GE will cease the ongoing debris removal and any other intrusive activities and will discuss with EPA appropriate response actions.

• Utilize a dive team to locate and facilitate removal of remaining debris targeted for removal. The dive team will identifY and connect cables to remaining debris targets to facilitate their removal, and will likely cut debris at the sediment surface using an underwater hydraulic chainsaw. It is anticipated that any cut debris will be buoyant and will be removed from the water surface; however, if the debris does not float, it may be left on the lake bottom and covered by the sediment cap if that would not interfere with the cap. It is expected that use of the dive team will minimize sediment disturbances by, at a minimum, eliminating the need to use the rake attachment to remove debris targets and eliminating (or minimizing) the need to use spuds to anchor the barge. It is also anticipated that use of a dive team will allow the intrusive debris removal activities to be completed during one working day.

In addition to the above-identified activities, in response to recent elevated PCB results in water column samples, which GE believes are also related to the debris removal activities, GE will install stop logs at the weir across the outfall channel to the Housatonic River (so as to temporarily halt flow from the Lake to the River) prior to resuming debris removal activities. The stop logs will be kept in the weir as long as possible during the debris removal activities.

GE proposes to continue the bank and near-shore sediment excavation activities as well as any non­intrusive activities (as discussed with EPA and MDEP), and will resume debris removal activities on May 13. In the meantime, non-intrusive work performed by the dive team is anticipated to start on May 9 in preparation for the debris removal activities. With EPA oversight, the dive team may cut some debris during these preparation activities to assess the buoyancy of such debris.

If, after the completion of debris removal activities, the data from the additional PCB air monitoring events do not show exceedances of the PCB notification level, GE will resume monthly PCB air monitoring in accordance with the Revised Scope of Work for air monitoring.

G:IGEIGE_Silver_Lake\Reports and Presentations\2013-05-08 air PCB exceedance\1181311214_SL air exceed notif-5-S.doc

Please contact me if you have any questions.

Sincerely yours,

Richard W. Gates Remediation Project Manager

Attachments

cc: Dean Tagliaferro, EPA Holly Inglis, EPA Tim Conway, EPA* Rose Howell, EPA (electronic copy) Robert Leitch, USACE (electronic copy) Linda Palmieri, Weston Solutions (2 hard copies+ electronic copy) John Ziegler, MDEP (2 hard copies+ electronic copy) Michael Gorski, MDEP (electronic copy) Eva Tor, MDEP (electronic copy) Mayor Daniel Bianchi, City of Pittsfield* Corydon Thurston, Executive Director, PEDA Rod McLaren, GE* Andrew Silfer, GE James Bieke, Sidley Austin LLP Mark Gravelding, ARCADIS Todd Cridge, ARCADIS Public Information Repositories GE Internal Repositories

* without attachments

G:IGEIGE_Si1ver_Lake\Reports and Presentations\20 13-05-08 air PCB exceedancel 1181311214 _SL air exceed notif-5-8.doc

Dave Dickerson May 8, 2013

Page 3 of3

G:\GE\GE_Silver_Lake\Reports and Presentations\2013-05-08 air PCB exceedance\1181311214_May 2013 PCB Results.xlsxSilver Lake - May 2013 Page 1 of 1 5/8/2013

Sampling Event Period

Field Blank (µg/PUF)

SL-1 (µg/m3)

SL-3 (µg/m3)

SL-4 (µg/m3)

SL-4CO (colocated)

(µg/m3)

Background BK-5

(µg/m3)

05/02/13-05/03/13 ND (<0.10) 0.22141,2 0.08541 0.14141,2 0.13111,2 0.0019

Notification Level 0.05 0.05 0.05 0.05 0.05 0.05Action Level 0.10 0.10 0.10 0.10 0.10 0.10

Notes:ND - Non-Detect

2 Represents an exceedance of the action level

AMBIENT AIR PCB DATA RECEIVED MAY 5, 2013

PCB AMBIENT AIR CONCENTRATIONSSILVER LAKE

GENERAL ELECTRIC COMPANY - PITTSFIELD, MASSACHUSETTS

1 Represents an exceedance of the notification level

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\\ RECREAT~ ~ AREA 5 • ' \

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I. BASE MAP INFORM ATION ADJACENT TO SILVER LAKE MODIFIED FROM ELECTRON IC FILE OF SURVEY P[RFORMED BY HILL ENGIN EERS, AR CHITECTS AND PLANN ERS IN 2D06 AND 2008. OTHER BASE MAP INFORMATION PHOTOGRAMMETRICALLY MAPPED FROM APRIL 1990 AERIAL PHOTOGRAPHS.

2 UTILITY LOCATIONS ARE APPROXIMATE AND ALL UTILITIES MAY NOT BE SH OWN. ALL PHYSICAL FEATURES MAY NOT BE SHOWN.

3 REMOVAL ACTION AREA BCXJNOARY AT WATER EDGE IS REPRESENTED BY THE APPROXIMATE MEAN WATER SURFACE ELEVATION (9 7 5.9).

4 AIR MONITORING LOCATIONS ARE APPROXIMATE. ACTUAL LOCATION S TO BE DETERMINED IN THE FIELD B Y BERKSHIRE ENVIRONMENTAL CONSULTANTS, INC.

LEGEND:

REMOVAL ACTION AREA BOUNDAR Y

------ APPROXIMATE PROPERTY LINE

PROPERTY 10

--980-- SURFACE ELEVATION (1-FT CONTOUR)

·~· EDGE OF BUSHES

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CJ I-FOOT REMOVAL

CJ 2- FOOT REMOVAL

CJ 3- FOOT REMOVAL

CJ 5- FOOT REMOVAL

CJ 6- FOOT REMOVAL

CJ 7-FOOT REMOVAL

CJ 8- FOOT REMOVAL

CJ 9- FOOT REMOVAL

CJ II-FOOT REMOVAL

liiiiiiiil 13-FOOT REMOVAL

CJ 15-FOOT REMOVAL

SL-1 ~ PROPOSED AIR MONITORING LOCATION

100' 200'

GRAPHIC SCALE

~ARCADIS