Publication Date

2018-5

Document Type

Honors Project

Degree Name

Bachelor of Arts

Department

Geosciences

Advisors

Robert Newton

Keywords

Lead, Zinc, Mercury, Mining, Heavy metals, Contamination, Industrial pollution, Anthropogenic pollution, Mercury poisoning, Lead poisooning, Wetland ecosystem, Mineral industries-Environmental aspects, Nature-Effect of human beings on, Wetland ecology

Abstract

In New Hampshire, historic mining operations associated with the former Madison Lead Mine have contaminated sediments in Cooks Pond (14.3 ha) with Pb, Zn, and Hg. The mine operated between 1826 and 1923, with the most intense activity after 1901. Lead, Ag and Zn were extracted from galena and sphalerite that occurred within a highly fractured hydrothermal deposit of Mesozoic age. Mine tailings from an ore processing facility were dumped directly into the pond leading to contamination of bottom sediments. A nearby pond, Durgin Pond, is unaffected by the mining operations and is used to assess the differences in local mineral-bound and regional atmospheric sources of mercury. Sediment cores were collected from Cooks Pond and Durgin Pond using a Uwitec gravity corer with secondary hammer action. Selected cores were sampled at 1cm intervals. Subsamples were then used for metal extraction using EPA method 1050A and analyzed for Pb, Zn and Se by ICP-OES and GFAAS methods. A second split was directly analyzed for Hg using a CVAAS Hg analyzer. Fish were collected, and fillets were analyzed for Hg, Pb and Se using the same methods as for sediments. The impact of the ore processing is clearly seen in the cores from Cooks Pond with peak concentrations of Pb (8,600 ppm), Zn (16,900 ppm) and Hg (460 ppb) at 28cm below the sediment water interface. This compares with the much lower maximum concentrations of 110 ppm Pb, 170 ppm Zn, and 340 ppb Hg measured at the Durgin Pond control site. The difference in total amount of metals between the two sites is even greater when considering the higher density of the clastic tailings in Cooks Pond compared with the organic rich sediments in Durgin Pond.

Rights

2018 Emma Elizabeth Harnisch. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.

Language

English

Comments

107 pages : illustrations (chiefly color) Includes bibliographical references (page 106-107)

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