Waste Site Cleanup & Reuse in New England

Air Monitoring During Full Scale Dredging (Fall 2004) - New Bedford Harbor Superfund Site

The first season of full scale dredging in the upper (northern) reaches of New Bedford Harbor began in September 2004. As part of this dredging of PCB-contaminated sediments, a comprehensive air monitoring program is being implemented to ensure that any airborne PCBs that result from the dredging, desanding, dewatering or water treatment operations are well below levels of concern. A total of ten air monitoring locations will be used throughout the two to three month dredging program in 2004, as described below.

Three air monitoring stations will be located at the desanding facility at the foot of Sawyer Street in New Bedford, and three additional air monitoring stations will be located at the dewatering facility on Hervey Tichon Avenue in New Bedford (in the North Terminal area of the harbor). An air monitoring unit will also be located on one of the dredging barges. These seven stations (plus a co-located sampler at one of them to address quality control) will be used to measure airborne PCBs at the three potential source locations associated with the harbor cleanup (i.e., the dredging, the desanding facility and the dewatering/water treatment facility)

Three additional air monitoring stations will be placed downwind of these three potential source areas in locations that include residential and commercial areas.

The data from these ten locations will be used for two purposes. First and foremost, the data will be compared to risk-based safe levels to ensure that airborne PCBs are below levels of concern. Since the adverse impacts associated with PCBs depend on long term (or chronic) periods of exposure rather than short term (or acute) individual episodes of exposure, this assessment will include a tracking effort to compare the cumulative exposure to airborne PCBs over the duration of the dredging program to long term acceptable levels.

The second use of the airborne PCB data will be to verify and improve the computer modeling that is being used for the site. Once verified, this modeling will continue to be used to identify potential impacts from the dredging and dewatering operations and, similarly, those locations best suited for air sampling to ensure the protection of human health.

Sample Location Date Airborne PCB Levels* New Bedford - Former Aerovox facility (shoreline) 09/08/04 1,000 ng/m3 New Bedford - Former Aerovox facility (shoreline) 09/08/04 1,100 ng/m3 New Bedford - Dredge (in river) 09/08/04 720 ng/m3 New Bedford - Manomet Street (near shoreline) 09/08/04 170 ng/m3 New Bedford - Coffin Avenue (near shoreline) 09/08/04 150 ng/m3 New Bedford - Sawyer Street desanding facility 09/08/04 28 ng/m3 New Bedford - Sawyer Street desanding facility 09/08/04 37 ng/m3 New Bedford - Sawyer Street desanding facility 09/08/04 56 ng/m3 New Bedford - North Terminal dewatering facility 09/08/04 19 ng/m3 New Bedford - North Terminal dewatering facility 09/08/04 16 ng/m3 New Bedford - North Terminal dewatering facility 09/08/04 47 ng/m3 New Bedford - Former Aerovox facility (shoreline) 09/14/04 1,449 ng/m3 New Bedford - Dredge (in river) 09/14/04 98 ng/m3 New Bedford - Manomet Street (near shoreline) 09/14/04 223 ng/m3 New Bedford - Coffin Avenue (near shoreline) 09/14/04 48 ng/m3 New Bedford - Sawyer Street desanding facility 09/14/04 64 ng/m3 New Bedford - Sawyer Street desanding facility 09/14/04 64 ng/m3 New Bedford - Sawyer Street desanding facility 09/14/04 86 ng/m3 New Bedford - North Terminal dewatering facility 09/14/04 38 ng/m3 New Bedford - North Terminal dewatering facility 09/14/04 39 ng/m3 New Bedford - North Terminal dewatering facility 09/14/04 61 ng/m3 New Bedford - Former Aerovox facility (shoreline) 09/22/04 590 ng/m3 New Bedford - Dredge (in river) 09/22/04 1,200 ng/m3 New Bedford - Manomet Street (near shoreline) 09/22/04 97 ng/m3 New Bedford - Coffin Avenue (near shoreline) 09/22/04 5 ng/m3 New Bedford - Coffin Avenue - duplicate 09/22/04 5 ng/m3 New Bedford - Sawyer Street desanding facility 09/22/04 7 ng/m3 New Bedford - Sawyer Street desanding facility 09/22/04 10 ng/m3 New Bedford - Sawyer Street desanding facility 09/22/04 17 ng/m3 New Bedford - North Terminal dewatering facility 09/22/04 6 ng/m3 New Bedford - North Terminal dewatering facility 09/22/04 5 ng/m3 New Bedford - North Terminal dewatering facility 09/22/04 19 ng/m3   Sample Location Date Airborne PCB Levels Former Aerovox facility (shoreline) 09/27/04 790 ng/m3 Dredge (in river) 09/27/04 2,700 ng/m3 Manomet Street (near shoreline) 09/27/04 420 ng/m3 Coffin Avenue (near shoreline) 09/27/04 340 ng/m3 Sawyer Street desanding facility 09/27/04 35 ng/m3 Sawyer Street desanding facility 09/27/04 170 ng/m3 Sawyer Street desanding facility 09/27/04 210 ng/m3 North Terminal dewatering facility 09/27/04 80 ng/m3 North Terminal dewatering facility 09/27/04 75 ng/m3 North Terminal dewatering facility 09/27/04 120 ng/m3 Former Aerovox facility (shoreline) 10/18/04 560 ng/m3 Dredge (in river) 10/18/04 700 ng/m3 Manomet Street (near shoreline) 10/18/04 260 ng/m3 Coffin Avenue (near shoreline) 10/18/04 36 ng/m3 Sawyer Street desanding facility 10/18/04 47 ng/m3 Sawyer Street desanding facility 10/18/04 48 ng/m3 Sawyer Street desanding facility 10/18/04 66 ng/m3 North Terminal dewatering facility 10/18/04 17 ng/m3 North Terminal dewatering facility 10/18/04 74 ng/m3 North Terminal dewatering facility 10/18/04 100 ng/m3 * Airborne PCB concentration (in billionths of grams per cubic meter of air, or ng/m3)