Water Chemistry of the Unconsolidated Deposits of the Metro East, Illinois area

SUMMARY OF THE GROUND-WATER QUALITY DATA FOR THE METRO EAST, ILLINOIS AREA

· Few detections at concentrations exceeding USEPA Maximum Contaminant Levels

(MCL’s) established for public supply

· Arsenic (MCL = 10 mg/L)

Maximum concentration = 20.2 mg/L

2 wells in St. Clair Co. (Collinsville, Belleville)

Outside American Bottoms, Mississippi River alluvial aquifer

Other samples <7 mg/L

· Nitrate (MCL = 10 mg/L)

Maximum concentration = 37.5 mg/L

2 samples (O’Fallon, nr. Worden)

Outside American Bottoms, Mississippi River alluvial aquifer

Other samples <6 mg/L

· Selected exceedences of USEPA Secondary (SR) and Health Advisory (HA)

Drinking Water Regulations

· Manganese

SR = 50 mg/L; 87% of samples

HA (life time, 300 mg/L) = 40% of samples

Maximum concentration = 1,520 mg/L

Outside American Bottoms concentrations = 100’s-1,000’s mg/L

Within American Bottoms (2 wells, east edge) = 1.6 and 68 mg/L

· Iron (SR = 300 mg/L)

47% of samples

Maximum concentration = 3,580 mg/L

Outside American Bottoms concentrations = 10’s-1,000’s mg/L

Within American Bottoms (2 wells, east edge) = <6 mg/L

· Trace-metal and inorganic concentrations generally unremarkable

At former Nike missile site near Marine

Lead, 1.08 mg/L

Elevated specific conductance (15,000 mS/cm),

Elevated sodium (1,020 mg/L), chloride (4,890 mg/L)

· Trace concentrations of VOC’s detected in 53% of well samples

· Benzene and/or Toluene

27% of samples, essentially all from Madison Co.

Maximum concentration = 0.03 mg/L

No detections within American Bottoms

· Chloroform

40% of samples

Maximum concentration = 3.03 mg/L

Within American Bottoms (1 well, east edge) = 0.06 mg/L

· MTBE

No detections

· Trace concentrations of pesticides detected in 53% of well samples

· Herbicides

53% of samples

Maximum concentration, prometon = 0.9 mg/L

Other concentrations = 0.10 mg/L or less (metolachlor ESA)

1 sample 11 pesticides detected (Bethalto, max = 0.9 mg/L)

1 sample 7 pesticides (Glen Carbon, max = 0.05 mg/L)

Atrazine and degradates (primarily deethylatrazine), 27% samples

Metolachlor and degradates (primarily ESA), 27% samples

Alachlor ESA, 27% of samples

Bentazon, 27% samples

Glyphosate compounds not detected

· Insecticides

3 samples (nr Marine, Edwardsville, Glen Carbon)

Maximum concentration, imidacloprid = 0.9 mg/L

Other concentrations = 0.05 mg/L or less (3-Ketocarbofuran)\

· Trace concentrations of antibiotics detected in only well sampled

· 3 human use (azithromycin, roxithromycin, ofloxacin), 1 animal use (tylosin)

· Maximum concentration, azithromycin = 0.116 mg/L

Home