Premium
Sources of mercury in a contaminated stream—implications for the timescale of recovery
Author(s) -
Southworth George,
Mathews Teresa,
Greeley Mark,
Peterson Mark,
Brooks Scott,
Ketelle Dick
Publication year - 2013
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.2115
Subject(s) - mercury (programming language) , environmental science , riparian zone , contamination , watershed , streams , environmental chemistry , environmental remediation , hydrology (agriculture) , remedial action , environmental engineering , ecology , chemistry , geology , biology , computer network , geotechnical engineering , machine learning , habitat , computer science , programming language
Mercury contamination in East Fork Poplar Creek in Tennessee arises from dissolved mercury exiting a headwater industrial complex and residual mercury in the streambed and soil throughout the watershed downstream. The headwater inputs generate chronic base flow concentrations of total mercury of about 1,000 ng/L, but most of the annual export of mercury from the system appears to originate farther downstream. Effective targeting of remedial efforts requires determining how long downstream sources might continue to contaminate the system following elimination of the headwater mercury inputs. The authors calculations suggest that (1) contaminated soils and sediments account for >80% of the annual mercury export from the entire watershed, with most export occurring during wet weather events; (2) bank erosion and resuspension of streambed particulates are the major mercury sources maintaining high annual mercury export rates; and (3) the inventory of particle‐associated mercury in the streambed was not large enough to sustain the estimated export rates for more than a few years. The authors findings imply that to prevent waterborne mercury contamination in this system from continuing for decades, remedial actions will have to control the headwater mercury source that sustains day‐to‐day base flow mercury concentrations and the riparian stream‐bank sources that generate most of the mercury export from the system. Environ. Toxicol. Chem. 2013;32:764–772. © 2013 SETAC