Sample Name: USW-4

Sample date: October 11, 2007
Operable Unit: 5
Sample Type: Water or Groundwater
Sample Depth: NA
Location Description: Filtered Underwater Seep

Contaminants above MCL for drinking water :

• Manganese
• Thallium

Latitude: +41.3208477      Longitude: -89.3070013

Metal Contaminants:

Contaminant	MCL	Amount Detected
Aluminum	0.05 to 0.2* mg/L	0.078 mg/L
Antimony	0.006 mg/L	<0.0029 mg/L
Arsenic	0.01 mg/L	<0.0032 mg/L
Barium	2 mg/L	0.061 mg/L
Beryllium	0.0002 mg/L	<0.0002 mg/L
Cadmium	0.005 mg/L	<0.0005 mg/L
Calcium	(No MCL)	80 mg/L
Chromium	0.1 mg/L	<0.0005 mg/L
Cobalt	(No MCL)	<0.0016 mg/L
Copper	1.3 mg/L	0.0019 mg/L
Iron	0.3* mg/L	<0.0098 mg/L
Lead	0.015 mg/L (Action Lvl)	<0.0021 mg/L
Magnesium	(No MCL)	44 mg/L
Manganese	0.05* mg/L	0.055 mg/L
Mercury	0.002 mg/L	<0.0001 mg/L
Nickel	(No MCL)	0.0051 mg/L
Potassium	(No MCL)	6.5 mg/L
Phosphorus	(No MCL)	NT mg/L
Selenium	0.05 mg/L	<0.0033 mg/L
Silver	0.10* mg/L	<0.0005 mg/L
Sodium	(No MCL)	67 mg/L
Thallium	0.002 mg/L	<0.004 mg/L
Vanadium	CCC^ mg/L	0.0026 mg/L
Zinc	5* mg/L	0.012 mg/L

Notes: A value of NT indicates that this sample was not tested for a particular contaminant. A value of ND indicates that the contaminant was not detected in the test that was done for it. *Indicates that the MCL (Maximum Contaminant Level) for drinking water is a secondary standard by the EPA. ^ Indicates a Chemical Contaminant Candidate issued by the EPA. # Indicates concentrations in excess of 0.1 mg/L suggest domestic of agricultural sources of waste.