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Trace Metal Analysis of Sediments in the Park River Watershed, Hartford, CT. Jonathan Gourley and Victoria Doñé Environmental Science Program Trinity College, Hartford CT. Acknowledgements. Trinity College’s Faculty Research Grant program - PowerPoint PPT Presentation
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Trace Metal Analysis of Sediments in the Park River Watershed, Hartford, CT
Jonathan Gourley and Victoria DoñéEnvironmental Science Program
Trinity College, Hartford CT
Acknowledgements
• Trinity College’s Faculty Research Grant program
• Trinity College undergraduate research students and faculty
• Mary Rickel Pelletier – Park River Watershed Revitalization Initiative
Photos by Kelsey Semrod
Regional basins with EPA designated impaired reaches
Park RiverWatershed
Hartford
24 of the 69 causes of impairment in the Lower Connecticut are listed as “CAUSE UNKOWN”
35%
27.5%
Of the approved TMDL studies for watershed- 76% are for E. Coli
Data from US EPA Section 303(d) List Fact Sheet for Lower Connecticut Watershed
What role do toxic trace metals play in the impairment of the Park River
Watershed?
Engage undergraduate students in long term research projects
T
1) Determine concentration of toxic trace metals in the Park River
sediment
• Watershed wide survey• Use Inductively Couple Plasma – Optical
Emission Spectroscopy (ICP-OES) to analyze sediment samples using weak-acid digestion following method of Giddings et al. (2000)
2) Identify local problem point sources
Photo by Nathan Sell
3) Compare sediment data to macroinvertebrate data
4) Model downstream transport of toxic metals
• Channelization and impervious runoff creates “flashy” storm events
• What is the sediment’s “memory” of toxic trace metals?
• What is the impact of contaminated Park River sediments on the Lower Connecticut watershed?
Photo by Nathan Sell
Hartford, CT 1864
North Branch
South Branch
Photo by Nathan Sell
19 %
28%
Park River Watershed Impervious Surfaces
Connecticut Department ofEnvironmental Protection
Leachate point source discharges
Which toxic trace metals are found in high concentration in the Park River
sediments?
• Impervious runoff, point source discharges from metal finishing industry
• Use Right To Know Network (RTK) to identify toxic metal discharges directly in to the River
• Pb, Zn, Cu, Cd• 2008 - Established baseline concentrations in
North Branch sediments
Sediment sample locationsfor trace metal analysis
upstream downstream
SQG Range = 270 – 820 ppm
PEC = 459 ppm
PEC = 149 ppm
upstream downstream
Range 3-10 ppm
PEC = 4.9 ppm
upstream
SQG Range = 3-10 ppm
Connecticut Department ofEnvironmental Protection
Leachate point source discharges
Good
Poor
Moving forward
• Determine availability of metals to biota – conduct acid-volatile sulfide (AVS) study
• Understand temporal variations in concentration; sediment memory
• Determine toxic metal contribution of Park River to Lower CT watershed
• Determine concentration of metals in water samples
FLOW
Contoured concentrations of Pb in sediments (ppm)
Conclusions
• Significant difference in trace metal concentrations between north and south branch of the Park River
• Significant difference in macroinvertebrate population of north and south branch
• Indentified sampling locations with high trace metal concentrations that are good candidates for detailed contaminant plume analysis
Thank You!
Photo by Nathan Sell