USGS Water Resources Division water quality site: 05587550
Site description: Mississippi River below Alton, IL
Hydrologic Unit Code (HUC): 07110009
Site UTM N: 4305082
Site UTM E: 748380
UTM zone: 15
Drainage area at water quality site: 171,500 mi2
Sampling frequency: monthly
   
Flow station: 05587500 (USGS daily flows)
Station description: Mississippi River at Alton, IL 
Hydrologic Unit Code (HUC): 07110009
Station UTM N: 4307586
Station UTM E: 744539
UTM zone: 15
Drainage area at flow station: 171,500 mi2
Period of record: 04/01/1933-09/30/1987
Flow conversion: none

Flow station: 05587450 (USGS daily flows)
Station description: Mississippi River at Grafton, IL 
Hydrologic Unit Code (HUC): 07110009
Station UTM N: 4316170
Station UTM E: 722807
UTM zone: 15
Drainage area at flow station: 171,300 mi2
Period of record: 04/01/1933-09/30/1997
Flow conversion: none

The following constituent values were removed from analysis as
possible outliers, or are below detection limits: none

Additional comments:
The gauging station at Alton, IL was discontinued on 09/30/1987. 
Mississippi River discharge after this date has been substituted
with the discharge at Grafton, IL.

Loads for this site were estimated with LOADEST2 version 1.10