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