Far Field Water Quality Monitoring (Resuspension)

Legend

PCB concentrations in parts per trillion (ppt)

Typical Operations: Far-field PCB concentration is less than the control level (350 ppt) and the standard (500 ppt)

Control Level: Far-field PCB concentration is between 350 ppt and 500 ppt. Additionally, the seven day running average is above 350 ppt.

Exceedance Level: Far-field PCB concentration exceeds the standard (confirmed occurrence)

Phase 1 Dredging Monitoring Schedule
Routine Monitoring is performed during typical operations, and Contingency Monitoring is performed when the Control Levels are exceeded.

Sampling Frequency Rogers Island Thompson Island Schuylerville (Lock 5) Stillwater Waterford Albany Poughkeepsie
Routine Weekly Daily Daily Weekly Daily Monthly Monthly
Contingency Daily Twice Daily Twice Daily - - Weekly Weekly

Baseline Monitoring Schedule

Sampling Frequency Rogers Island Thompson Island Schuylerville (Lock 5) Stillwater Waterford Albany Poughkeepsie
Baseline Monthly Weekly Weekly - Weekly Monthly Monthly

Weekly Calendar (Please click on data for more information)
Dredging occurred between May 15 - Oct 26, 2009. Performance standard monitoring data was collected daily between May-Dec 2009. Once all Phase 1 river activities were completed, and baseline (pre-dredging) water PCB levels were reached, weekly monitoring began (December 28, 2009). Baseline monitoring results are received in accordance with standard lab turnaround time (approx. 21 days).

<<    Week of Mar 07, 2010    >>
Rogers IslandThompson Island Thompson Island (additional results)Schuylerville (Lock 5)StillwaterWaterfordAlbanyPoughkeepsie
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Mar 08-Data Pending-Data Pending-Data Pending--
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Engineering Performance Standards: Resuspension

Strict Engineering Performance Standards have been developed to minimize resuspension of PCBs during dredging to limit the transport of PCBs and protect water intakes.

What is the Standard?

The performance standard for dredging resuspension sets a resuspension level of 500 parts per trillion (ppt) Total PCBs – the EPA drinking water standard under the Safe Drinking Water Act.

How is the Standard Measured?

Through an extensive river water quality monitoring program at upstream, “near-field” and “far-field” stations.

  • near-field: within 300 meters downstream of dredge (turbidity, total suspended solids and metals)
  • far-field: greater than 1 mile downstream (total suspended solids, metals and PCBs)
    (see Far Field Water Monitoring Locations map at left)
EPA