Of Time and the River
The Period 1972 to Present
 

  State of Illinois

The IEPA is required to file a Water Quality Report pursuant to Section 305(b) of the Clean Water Act; the latest report is filed in May 2004 and includes the most recent water quality standards (Table 26) and an overview of conditions in the state.

Table 26: Illinois Water Quality Standards (IEPA 2004)

 
Parameter Units General Use Public and Food Processing Water Supply Secondary Contact and Indigenous Aquatic Life
pH SU 6.5 minimum 9.0 maximum --- 6.0 minimum 9.0 maximum
Dissolved Oxygen mg/l 5.0 minimum --- 5.0 minimum(2)
Arsenic µg/l (3) 50 1000
Barium µg/l 5000 1000 5000
Boron µg/l 1000 --- (4)
Cadmium µg/l (3) 10 150
Chloride mg/l 500 250 ---
Chromium (Total) µg/l --- 50 ---
Chromium (Trivalent) µg/l (3) --- 1000
Chromium (Hexavalent) µg/l (3) --- 300
Copper µg/l (3) --- 1000
Cyanide mg/l (3) --- 0.1
Fluoride mg/l 1.4 --- 15
Iron (Total) µg/l --- --- 2000
Iron (Dissolved) µg/l 1000 300 500
Lead (Total) µg/l --- 50 100
Lead (Dissolved) µg/l (3) --- ---
Manganese µg/l 1000 150 1000
Mercury µg/l (3) --- 0.5
Nickel µg/l (3) --- 1000
Phenols µg/l 100 1 300
Selenium µg/l 1000 10 1000
Silver µg/l 5 --- 100
Sulfate mg/l 500 250 ---
Total Dissolved Solids mg/l 1000 500 1500
Total Residual Chlorine µg/l (3) --- ---
Zinc µg/l (3) --- 1000
Fecal Coliform Bacteria
May-Oct count/100ml 200(5) 2000(5) ---
Nov-April count/100ml --- 2000(5) ---
Ammonia Nitrogen (Total) mg/l 15(6) --- ---
Unionized Ammonia Nitrogen mg/l (4) --- 0.1
Nitrate Nitrogen mg/l --- 1 ---
Oil and Grease mg/l --- 0.1 15
Total Phosphorus mg/l 0.05(7) --- ---
Aldrin µg/l --- 1 ---
Dieldrin µg/l --- 1 ---
Endrin µg/l --- 0.2 ---
Total DDT µg/l --- 50 ---
Total Chlordane µg/l --- 3 ---
Methoxychlor µg/l --- 100 ---
Toxaphene µg/l --- 5 ---
Heptachlor µg/l --- 0.1 ---
Heptachlor epoxide µg/l --- 0.1 ---
Lindane µg/l --- 4 ---
Parathion µg/l --- 100 ---
2,4-D µg/l --- 100 ---
Silvex µg/l --- 10 ---
Benzene µg/l (3) --- ---
Ethylbenzene µg/l (3) --- ---
Toluene µg/l (3) --- ---
Xylene(s) (Total) µg/l (3) --- ---


  1. 35 Ill. Adm. Code 302 (2002).
  2. Excluding the Calumet-Sag channel, which shall not be less than 3.0 mg/l at any time.
  3. Acute and Chronic Standards.
  4. (-) Means no numeric standard specified, narrative standard applies.
  5. Geometric mean.
  6. The allowable concentration varies in accordance with water temperature and pH values.
  7. Standard applies in particular inland lakes and reservoirs and in streams at the point of entry into these lakes or reservoirs.

IEPA’s Non-point Source Management Program (NPSMP) inventories and describes Illinois’ existing non-point source pollution control activities and initiatives. This assessment is done as required by Section 319 of the 1987 Clean Water Act. Table 27 summarizes the updated non-point source assessments.

Table 27: Summary of Potential Non-point Sources of Impairment (IEPA 2004)

 
  Streams Inland Lakes
Category Miles % of Miles Acres % of Acres
  Assessed Assessed Assessed Assessed
Use Impairments due to Potential Non-point Sources Only 3,471 23.0 84,079 54.6
Use Impairments due to Potential Point and Non-point Sources 1,429 9.5 43,309 28.1
Use Impairments due to Potential Point Sources only 170 1.1 0 0.0
No Use Impairments 6,499 43.1 9,151 5.9
Total Assessed 15,069 100.0 154,048 100.0
Waters Potentially Needing Additional Non-point Source Corrective Action 4,900 32.5 127,388 82.7