Potomac Toxics Monitoring Status and Issues

1
Potomac Toxics MonitoringStatus and Issues

• ICPRB
• March 8, 2004

2
Interstate Cooperation for Potomac Toxic TMDLs

• Cooperation and coordination of state data
  collection efforts by DC, MD, VA
• Ongoing coordination meetings
• Joint RFP for funding of fall line monitoring
• Possible CBP Toxics Subcommittee Workgroup for
  monitoring guidelines
• Exploration of feasibility of single contaminant
  fate and transport model

3
Contaminants of Concern

• DC
• PCBs
• Chlordane
• PAHs
• DDT and mercury?

• MD
• PCBs
• Metals? (pending further toxicity testing)
• VA
• PCBs
• Others?

4
Data Needs for TMDL Model Support

• Main channel water column data
• For model calibration
• Bed sediment core data
• For understanding of vertical mixing
• Surficial bed sediment data
• For model initialization
• For model calibration/verification
• Storm and non-storm monitoring data
• For estimating mass loads

5
Existing/Historical Data(see ICPRB website for
copies of presentations at Technical Workshop on
Potomac Toxics Data)

• Historical CBP water column and bed sediment data
  found to be not really usable
• Potomac fall line monitoring data
• 1990s data for metals
• Early 1990s data (limited) for PCBs and other
  organics
• Anacostia River data reasonably good water
  column, bed sediment and loading data

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Upcoming Data Collection Efforts

• MDE/USGS/PG County monitoring to collect loading
  data for upstream tributaries of Anacostia River
  using automatic sampling technology
• DCDOH Potomac River main channel water column
  sampling
• DCDOH Potomac River sediment core study
• MDE Potomac estuary sediment toxicity study for
  metals
• DCDOH/MDE/VADEQ Potomac fall line monitoring and
  NPDES permittee monitoring to collect loading
  data proposal submitted to EPA Office of
  Wastewater by ICPRB

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Issues Limiting Usefulness of Data

• Inconsistent sets of parameters
• Inadequate detection limits
• Incompatible sampling methodologies

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Inconsistent Sets of Parameters

• PCBs 209 congeners
• Most labs only measure concentrations of a subset
  of congeners
• tPCBs (total PCBs) sum of all 209 congeners
• PAHs large family of chemicals
• Labs typically measure concentrations of 10 to 30
  PAHs
• Total PAHs depends on subset of PAHs measured
• Chlordane various isomers and metabolites exist
• Total chlordane depends on species measured

9
Inadequate Detection Limits

• tPCB detection limits
• Typical NPDES permit DL 1000 ng/L
• Method 608 65 ng/L
• Method 8082 54 900 ng/L
• Method 1668A 0.01 ng/L
• tPCB concentrations of interest
• Typical non-storm Anacostia River 1 10 ng/L
• Typical DC storm sewer water 10 100 ng/L
• DC Water Quality Standard 0.045 ng/L

Joel Baker (CBL), ICPRB Technical Workshop on
Potomac River Toxics Data
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Sampling Methodologies Used for Load Estimation

• Storm composite samples several grab samples
  from a storm are composited before analysis
• Event mean concentration (EMC) flow-weighted
  average of storm concentrations are computed
• Linear regression predictions of concentration as
  function of flow, other many grab samples
  collected for range of flows, conditions

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Needs for Upcoming Monitoring

• States need to agree upon list of classes of
  chemicals to be monitored
• e.g. PCBs, PAHs, chlordane, selected metals?
• Should mercury be included?
• Committee of chemists and modelers need to
  produce quick draft monitoring guidelines for
  each class of chemicals
• Lists of parameters for each class
• Agreement on detection limits for each class
• Agreement on method of monitoring for load
  estimates

12
Possible Means of Coordination

• CBP Toxics Subcommittee
• has offered to form ad hoc Workgroup to formulate
  draft Potomac River monitoring guidelines
• Has offered to submit proposal for STAC Workshop
  for peer review of guidelines