LOCATION.-- Lat 39°18'16", long 89°47'15" (NAD of 1927), in SW1/4NW1/4 sec.20, T.10 N., R.6 W., Macoupin County, Hydrologic Unit 07130007, 0.1 mi. upstream from Sugar Creek, 0.5 mi downstream from Shaw Point, and 1.8 mi northeast of Carlinville. To reach gage, drive east from Carlinville 1.6 mi then turn north on county road and drive 0.7 mi to site.

DRAINAGE AREA.-- 132 mi²

PERIOD OF RECORD.--

SURFACE-WATER QUALITY

MISCELLANEOUS: Water years 1979 and 1997.

BIOLOGICAL

BENTHIC MACROINVERTEBRATES: Water year 1997.

REMARKS.--Established in the summer of 1979 as a coal hydrology synoptic site downstream of mining activity. Station established as a low-flow water-quality sampling site in August 1997 as part of the National Water-Quality Assessment (NAWQA), Lower Illinois River Basin synoptic study.

REMARKS FOR CURRENT YEAR.-- Benthic macroinvertebrate community samples were collected as part of the National Water-Quality Assessment program (NAWQA) in the lower Illinois River Basin. One quantitative (Richest-Targeted Habitat) sample was collected in accordance with the NAWQA protocols (Cuffney and others, 1993). The quantitative sample was a composite of macroinvertebrates from about 10 submerged tree branches. Branches were cut underwater, gathered in a 425µm mesh net, and invertebrates were washed or picked from the branches. The average length and average diameter of each branch were measured and used to calculate an approximate surface area. All samples were processed by the USGS National Water-Quality Laboratory. Phylum, Class, Order, Suborder, Family, Subfamily, and Tribe are listed and arranged according to the USGS National Water-Quality Laboratory taxonomic hierarchy. Reach A begins 120 meters upstream from the SR 20 bridge and continues upstream for 100 meters. The surface area sampled at reach A was 0.30 m².