Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA

Environmental Geochemistry and Health
By: , and 

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Abstract

Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6–2 times higher than those in the upper water column (23–25 μg/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lake-bed sediments ranged up to 694 mg/kg in highly organic material from the tops of sediment cores but were <15 mg/kg in geologic substrate. During warm months, reduced As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to be in the sediments, indicating that elevated levels of As in the lake will persist for decades.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Distribution and seasonal dynamics of arsenic in a shallow lake in northwestern New Jersey, USA
Series title Environmental Geochemistry and Health
DOI 10.1007/s10653-010-9289-7
Volume 33
Issue 1
Year Published 2011
Language English
Publisher Springer
Contributing office(s) New Jersey Water Science Center
Description 22 p.
First page 1
Last page 22
Country United States
State New Jersey
Other Geospatial Lake Mohawk
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