Analyses in Support of the Development of the PBT Monitoring Strategy

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Analyses in Support of the Development of the PBT
Monitoring Strategy

• Tim Watkins and Stan Durkee
• EPA / ORD

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Purpose

• Currently, we are undertaking analyses addressing
  mercury, dioxin and PCBs to
• Enhance our understanding of current monitoring
  programs addressing various media and the extent
  to which partnerships and information-sharing
  exist
• Assess these PBT monitoring programs against our
  draft Strategy objectives and,
• Provide insight and information to help refine
  our draft Strategy objectives.

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Specific Analyses

• Assessment of current monitoring programs.
• Evaluation of Hg monitoring sites in one network
  using modeled Hg deposition values.
• Investigation of EPA fish tissue study design.
• Dioxin modeling exercise.

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A Multimedia Matrix for Monitoring Selected PBTs
(An Analytical Tool)
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Initial Focus on Mercury

• A lot of interest and activity
• Data availability
• Major monitoring programs in all media

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Mercury Monitoring

• Can national strategy objectives be developed for
  individual media?
• Can national strategy objectives be developed to
  link multimedia monitoring systems?
• To help answer these questions, we are first
  examining the mercury deposition network (MDN).

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Mercury Deposition Network

• A collaborative network sponsored by over 100
  state and federal agencies, native American
  tribes and others.
• In 2000, more than 50 sites in operation.
• Collects weekly wet-only samples of precipitation
  at sites worldwide, analyzing total mercury (also
  methylmercury at 1/3 of the sites).

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Modeling Can Support Monitoring Design

• EPA modeled, using RELMAP, the domestic long
  range transport of U.S. emissions and reported
  the results in the 1997 Mercury Study Report to
  Congress.
• For this analysis, we have evaluated MDN
  monitoring sites against our Strategy objectives
  using the modeled results of Hg wet deposition.
• A detailed description follows this presentation.