Surface-Water Activities for the National Water-Quality Assessment Program,
Lower Illinois River Basin
Paul J. Terrio
Surface-water activities in NAWQA focus on assessing physical
and chemical characteristics of stream water, including suspended sediment,
dissolved solids, major ions and metals, nutrients, organic carbon, and
dissolved pesticides, and on relating these c haracteristics to hydrologic
conditions, sources, and transport. The sampling design includes sampling
on a monthly frequency at eight fixed stations, extreme-event sampling
at these fixed stations, and synoptic sampling during low-flow conditions
at appr oximately 24 stations located throughout the basin. The fixed stations
consist of two types of sites, Integrator Sites, representing streams
in heterogeneous large basins affected by complex combinations of land-use
settings, point sources, and nat ural influences and Indicator Sites,
representing streams in relatively homogeneous smaller basins associated
with specific individual environmental settings.
U.S. Geological Survey
221 N. Broadway
Urbana, IL 61801
(217) 344-0037
pjterrio@usgs.gov