Sedimentation and sediment chemistry, Neopit Mill Pond, Menominee Indian Reservation, Wisconsin, 2001

The volume, texture, and chemistry of sediment deposited in a mill pond on the West Branch of the Wolf River at Neopit, Wis., Menominee Reservation, were studied in 2001-2002. The study was accomplished by examining General Land Office Survey Notes from 1854, establishing 12 transects through the mill pond, conducting soundings of the soft and hard bottom along each transect, and collecting core samples for preliminary screening of potential contaminants. Combined information from transects, cores, and General Land Office Survey notes were used to reconstruct the pre-dam location of the West Branch of the Wolf River through the mill pond. Neopit Mill Pond contains approximately 253 acre-ft of organic-rich muck, on average about 1.2 ft thick, that was deposited after the dam was built. Elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with creosote and pentachlorophenol were found in post-dam sediment samples collected from Neopit Mill Pond. Trace-element concentrations were at or near background concentrations. Further study and sampling are needed to identify the spatial extent and variability of the PAHs, pentachlorophenol, and other byproducts from wood preservatives