Date of Award

12-2008

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Environmental Toxicology

Advisor

Rodgers, John H

Committee Member

English , William R

Committee Member

Hitchcock , Daniel R

Abstract

Campus parking lot stormwater (CPLSW) runoff mobilizes a variety of constituents from vehicular and atmospheric deposition that may pose risks to receiving aquatic systems. The overall objective of this research was to provide an approach for risk characterization, toxicity identification, and remediation of constituents of concern in CPLSW. The specific objectives of this research were to: (1) Characterize campus parking lot stormwater (CPLSW) to discern the constituents of concern present in these waters; (2) Perform TIE manipulations to identify possible fractions of concern in CPLSW, and; (3) Evaluate the performance of a pilot-scale constructed wetland treatment system (CWTS) designed to treat simulated CPLSW. Physicochemical measures of general water chemistry, metals, and oil and grease preceded toxicity tests. Toxicity tests and TIEs were performed using two sentinel species, Pimephales promelas Rafinesque and Ceriodaphnia dubia Richard in 7 day static/renewal tests with USEPA testing protocols as guidelines. Maximum concentrations of inorganics measured in samples of CPLSW were: 4,756 µg Al/L, 53 µg Cu/L, 1,206 µg Ni/L, and 908 µg Zn/L. Fish (P. promelas) were more sensitive to CPLSW than C. dubia with decreased survival in 92% and 15% of the samples (n=13), respectively. Using USEPA TIE methodology, aeration and solid phase extraction were each successful for decreasing mortality of P. promelas. Aerating the CPLSW samples for 14 days decreased mortality and increased reproduction of C. dubia. The decrease in toxicity due to aeration and solid phase extraction suggests volatile or readily oxidizable compounds and non-polar organics are primary causes of toxicity. Although CPLSW varied widely in composition and toxicity, constituents of concern included: pH, alkalinity, total suspended solids, biological oxygen demand, chemical oxygen demand, metals, and oil and grease. Pilot-scale CWTS experiments were conducted using simulated CPLSW. In this pilot-scale CWTS, decrease concentrations of constituents of concern (e.g. Al, Cu, Ni, Zn, and oil and grease) were achieved from untreated (inflow) to treated (outflow) in all formulations of simulated CPLSW tested. Consequently, toxicity to P. promelas and C. dubia decreased from inflow to outflow, indicating the potential for remediation through removal of primary constituents of concern.

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