MINUTES
TRACE ELEMENT NATIONAL SYNTHESIS PLANNING TEAM (TENSPT)
JANUARY 5-8, 1998
WESTERN REGION OFFICE, MENLO PARK, CA
Attendees:
TENSPT -- Bill Brumbaugh, Roger Fujii, Dennis Helsel, Art Horowitz,
Mike Koterba, Jim Kuwabara, Rich Wanty, Denny Wentz, and Bill Wilber
The TENSPT would like to thank the following individuals for providing
input:
Carol Couch (Ecological Synthesis Planning Team or ESPT), Dave
Krabbenhoft, Terry Short, Pete VanMetre, and Jim Wiener (BRD,
LaCrosse, WI) attended some sessions.
Marty Gurtz, Tom Lopes, Glenn Patterson, and John Zogorski attended
some sessions by telephone.
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Monday, January 5
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PM -- MINING SUBGROUP
Issues Driving Our Interest:
Effects of mining on biota, especially fisheries
Effects on human health from exposure via drinking water
Questions:
1. How do trace element concentrations in bed sediment and aquatic
biota vary along gradients of mining type and intensity? At what
trace element concentrations do fisheries begin to show adverse
effects? How do the latter concentrations compare with existing
standards?
2. What are the impacts of mining and/or remediation on trace element
concentrations in the used ground water resource? How do trace
element concentrations in ground water compare with existing
standards?
3. What are the impacts of mining and/or remediation on surface water?
How does surface water draining reclaimed mine areas compare with
that from unmined areas in same location? What trends in trace
element concentrations are attributable to remediation?
NAWQA Components Involved:
1. Synoptics of bed sediment and tissue occurrence and distribution
along mining gradients.
2. LUS (land use studies) in mined areas, if wells are used for rural
supply.
3. BFS (basic fixed sites) in indicator basins to compare reclaimed
and unmined areas.
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Tuesday, January 6
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AM -- URBANIZATION SUBGROUP
Issues Driving Our Interest:
Effects of urbanization on stream biota
Effects on human health from exposure via drinking water
Questions:
1. How do trace element concentrations in ground water with potential
for use as drinking supply vary along an urban residential gradient?
2. How do trace element concentrations in bed sediment vary along an
urban gradient? What are major sources of trace elements to urban
streams?
3. How do trace element concentrations in sediment vary with time and
as a function of land use change? What are the rates of
accumulation of trace elements in urban watersheds?
4. What are the biological effects of elevated concentrations of trace
elements in bed sediment in urban streams? In what urban settings
are trace elements a major factor in aquatic biological health?
NAWQA Components Involved:
1. Urban LUS focused on new residential areas located either over or
upgradient from aquifers used for drinking water.
2. Bed sediment and tissue synoptics across urban gradients. For
selected SUs with key urban areas, sample at 30+ BS/T (bed sediment
and tissue) sites.
3. Sediment cores in urban reservoirs to address trends and whether
spatial patterns along urban gradients are also reflected over time
in cores as urban areas are developed.
4. Ecological synoptics (benthic invertebrates?) designed to measure
an effect due to urbanization.
PM -- REFERENCE CONDITIONS SUBGROUP
Issues Driving Our Interest:
What's normal?
How do background concentrations relate to drinking water or aquatic
life standards?
What concentrations of trace elements are present in edible fish from
reference areas?
Questions:
1. What are the occurrence and distribution of trace element
concentrations in the used ground water resource from reference
areas? How do these concentrations compare to those from urban and
mined areas?
2. What are the occurrence and distribution of trace element
concentrations in bed sediment and aquatic biota from reference
areas? How do these concentrations compare to those from urban and
mined areas? How well can we predict trace element concentrations
in bed sediment from heterogeneous settings based on measured
concentrations in sediment from homogeneous settings?
3. How do trace element concentrations from reference areas compare to
proposed standards for (1) protection of aquatic life, and (2)
exposure to humans from drinking water and edible fish.
NAWQA Components Involved:
1. Analysis of trace elements in five reference wells substituted for
five land use wells in each LUS. Analysis of trace elements in all
SUS (subunit survey) wells located in the used ground water
resource.
2. Sampling of additional reference sites as part of BS/T synoptics.
Analysis of trace elements in sediment cores collected from
reservoirs downstream from basins with little urban or mining
activity.
3. Analysis of total Hg in fillets of edible fish from reference
sites. Analysis of trace elements in whole-body, universal prey
organisms. Analysis of trace elements in water column samples at
selected surface water synoptic sites during low and high flow.
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Wednesday, January 7
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AM -- HG SUBGROUP
Issues Driving Our Interest:
Aquatic ecosystem health
Human health (fish consumption)
Questions:
1. What are the occurrence and distribution of Hg in fish tissue?
What are the relative importances of source and land use on
bioaccumulation? Do the levels of Hg in edible fish tissue present
a health hazard for humans and wildlife?
2. What are the occurrence and distribution of Hg and MeHg (methyl
mercury) in bed sediment? What are the relative importances of
source and land use on Hg accumulation in sediment and on Hg
methylation?
3. What data gaps exist in our current understanding of Hg in the
aquatic environment?
4. What are the occurrence and distribution of mercury species (Hg-T,
methyl-Hg, reactive-Hg, gaseous Hg) in aqueous phases? What
controls mercury speciation in aquatic ecosystems? What controls
mercury exposure and toxicity for humans and wildlife?
NAWQA Components Involved:
1,2. BS/T synoptics to look at spatial trends along gradients of proposed
factors. Add MeHg to (current) total Hg analyses. Measure Hg in
fillets or whole fish.
3. Retrospective analyses.
4. Low-level speciation analyses as part of surface water studies.
PM -- HUMAN EXPOSURE SUBGROUP
Issues Driving Our Interest:
Human health -- drinking water
Human health -- fish consumption
Questions:
1. What is the occurrence and distribution of trace elements in source
waters (from ground water) as a function of human and natural
environments?
2. What is the occurrence and distribution of trace elements in source
waters (from surface water) as a function of human and natural
environments?
3. What are concentrations of trace elements in fish where
concentrations are high in bed sediment?
NAWQA Components Involved:
1. Analyze trace elements in all SUS wells located in a used ground
water resource. Analyze trace elements in LUS wells that represent
a used resource (even if the well itself is not a supply well).
2. Analyze trace elements at BFS located near drinking water intakes.
Type of sample not yet known -- could be composite, etc.
3. Analyze Hg in fish fillets. Analyze other trace elements in
fillets if concentrations are elevated in bed sediment.
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Thursday, January 8
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AM -- IMPACTS ON 1997 STUDY UNITS
* Priorities are on existing NAWQA Program components -- BS/T,
LUS, SUS
* Little surface water column sampling for trace elements
* Integration with other national synthesis objectives --
e.g., targeting new residential growth in urban areas
* Additional locations for bed sediment sampling may be
required in some study units
Spatial synoptics are the best way to get information, not only at the
extremes of a gradient, but along the entire range. Work with the 97
study units to develop synoptics covering the range of an urban or
mining gradient, consistent with plans being developed by ESPT.
PM -- WHERE DO WE GO FROM HERE?
Issues that need resolution --
Tissues -- Bill Brumbaugh, lead. Get reactions to recommendation to
drop livers from BS/T Occurrence and Distribution Assessment and
analyze fillets and/or whole body, and to analyze only Hg unless high
concentrations of other trace elements are seen in bed sediment.
Bring discussion paper by Short and DeWeese plus outside comments to
next meeting and, after joint discussion, have TENSPT make
recommendation to NLT.
Biological Effects -- Denny Wentz, lead. Work with ESPT to identify
appropriate indices for stream ecosystem health in relation to trace
element effects, especially for mined and urban areas.
Partial vs Total Extractions -- No lead / no action pending. Unless
an extraction method can be identified that correlates well with
"biologically available" trace elements, continue to do totals.
Targeted studies may be done by selected 1997 study units during the
second year of the HIP to compare total trace element concentrations
in bed sediment with those found using an extraction technique that
better indicates changes along a gradient. Emphasis would be on
prediction of biological availability along a gradient of mined and/or
urban land use and would be based on Trace Element National Synthesis
Team (not TENSPT) recommendations.
Filtration -- Dennis Helsel, lead. Evaluate existing information to
identify benefits and costs of going to a smaller pore size for
filtering ground water samples to better measure what people are
consuming (at least a minimum value). Ensure we're not going a
different direction than the rest of the Division.
Which trace elements should be studied? -- Denny Wentz, lead. Use
lists from Circular 1021 and the April 1997 trace element meeting as a
starting point. Find out what Karen has seen consistently in the 1991
study unit data, and what Pete has seen consistently in reservoir
sediment cores, etc. Review published standards. For each element,
we need to have a reason for inclusion, either elevated presence, or
human or ecosystem health.
Stratification -- Select a national geology coverage and outline a
plan for stratification that addresses issues related to mining,
urbanization, reference conditions, human exposure, and mercury. This
issue is likely to extend beyond the purview of the TENSPT. Several
people, including Karen Rice, Barb Ruddy, and Denny Wentz have been
working on this issue.
Action Items --
Complete Question/Cost/Benefit Matrix by 1/19/98 -- subgroup leaders.
Complete matrix of work elements, listing questions addressed, program
components, costs, and importance to NAWQA Program, along with
suggested trace elements for analysis. (COMPLETED)
Draft minutes to TENSPT/NLT for review by 1/23/98 -- Helsel/Wentz
(COMPLETED)
97 study unit chiefs meeting, 2/9-12/98 -- Dennis Helsel, lead.
Compile notes and present simplified workplan matrix showing what
we're thinking and timelines for decisions. Encourage coordinated
synoptic studies among study units with issues (particularly
urbanization and mining) that are similar among the study units and
that are consistent with TENSPT recommendations. (COMPLETED)
Complete separate draft reports addressing each of the the five trace
element issues of concern and distribute to the National Leadership
Team by March 20, 1998 -- subgroup leaders.
Next Meeting -- 3/30-4/2/98 in Denver. National Leadership Team to
attend the last day.