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Boston Harbor Project Overview

Boston Harbor Project Overview. Effluent Quality. Effluent Quality. Historical Pollutant Loadings Trends in TSS, BOD and PCB Concentrations Review of PCB Control Efforts “Total” PCB Method Issues. Review of Control Efforts . MWRA Regulations prohibit discharge of PCBs

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Boston Harbor Project Overview

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  1. Boston Harbor Project Overview Effluent Quality

  2. Effluent Quality • Historical Pollutant Loadings • Trends in TSS, BOD and PCB Concentrations • Review of PCB Control Efforts • “Total” PCB Method Issues

  3. Review of Control Efforts • MWRA Regulations prohibit discharge of PCBs • Only two active industrial discharges have tested positive in 4 years (1700 samples tested). Both of these were stopped for remediation • Enforcement relies on an EPA approved method w/ 100 - 200 ng/L Aroclor MDL

  4. Review of Control Efforts • Sludge cake concentration implies a daily loading of 40 - 70 g to DITP • Up to 15 g/day may be attributed to unabsorbed dietary intake (1 - 2 g/day is more likely) • Seasonal increases may support a groundwater I&I component

  5. Total PCB Method Issues • Revised HHC is 0.17 ng/L “total of all congener or isomer analyses” • Methodology was not discussed in the revision • Currently measure only ~20 of 209 possible congeners • These account for only about 1/3 of the true total

  6. Total PCB Method Issues • “Modified Method 680” as listed in the new permit does not exist • GC/MS methods lose sensitivity with increasing levels of chlorination • GC/ECD methods become increasingly difficult as more analytes are added • MWRA plans to propose 67 congener list targeted at >80% of true total

  7. Aroclor Standard Percent Recovery

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