STATION NAME:  OHIO RIVER AT DAM 53 NEAR GRAND CHAIN 
STATION NUMBER:  03612500            
STATE: ILLINOIS                   
COUNTY: BOONE

                  	STATISTICAL SUMMARY OF SELECTED WATER QUALITY DATA COLLECTED FROM OCT  1954 TO  JUN   1994


                                                                                       PERCENT OF SAMPLES IN WHICH VALUES
                                               DESCRIPTIVE STATISTICS                WERE LESS THAN OR EQUAL TO THOSE SHOWN
 ------------------------------------- --------------------------------------  ------------------------------------------------------
                                       SAMPLE                                                          (MEDIAN)
    #WATER-QUALITY CONSTITUENT          SIZE    MAXIMUM    MINIMUM       MEAN      95 %       75 %       50 %       25 %        5 %
 ------------------------------------- --------------------------------------  ------------------------------------------------------
 FIELD MEASUREMENTS

 00061 DISCHARGE, INST. CFS              168    1060000  36900.000 290419.625  760599.875 406750.000 214000.000 116250.000  58360.000
 00095 SPECIFIC CONDUCT US/CM @ 25C      749    693.000    150.000    328.024     471.000    372.000    318.000    279.000    225.000
 00010 WATER TEMPERATUR (DEGREES)        397     31.000      0.500     17.105      29.500     26.500     17.000      8.000      3.500
 00400 PH, WH, FIELD    (STANDARD UNIT   682      9.000      5.500      7.395       8.185      7.700      7.400      7.200      6.500
 00410 ALKALINITY,WH,FE (MG/L AS CACO3   350    120.000     39.000     74.474     102.000     84.000     72.000     66.000     54.000
 00418 ALKALINITY,DIS,F (MG/L AS CACO3    39    102.000     53.000     75.692      93.000     85.000     74.000     69.000     57.000
 00453 BICARBONATE,DIS, (MG/L AS HCO3)    35    124.000     65.000     91.200     116.800    103.000     91.000     82.000     65.000
 39086 ALKALINITY,DIS,I (MG/L AS CACO3    35    102.000     53.000     74.743      95.600     84.000     75.000     67.000     53.000
 00300 OXYGEN DISSOLVED (MG/L)           141     15.000      3.100      9.185      12.990     11.000      9.000      7.500      5.500
 00301 OXYGEN DIS. PERC % OF SATURATIO   114    125.000      6.000     88.439     109.250     97.250     91.500     83.000     55.250

 BACTERIA

 31625 COLIFORM FECAL 0 COLS./100 ML     115   2000.000      1.000    143.991     532.000    150.000     79.000     26.000      7.800
 31673 FECAL STRPT KF A COLS./100 ML     120   6400.000      3.000    403.500    1695.000    247.500     80.000     38.250      7.000

 NUTRIENTS

 00631 NO2 + NO3 DISSOL (MG/L AS N)      165      2.800      0.190      1.005       1.900      1.300      0.990      0.640      0.243
 00608 NITROGEN AMMONIA (MG/L AS N)      161      0.240     <0.010      0.057*      0.160      0.070      0.050      0.030     <0.010
 00613 NITROGEN,NITRITE MG/L AS N        116      0.130     <0.010      0.026*      0.080      0.030      0.020      0.010     <0.010
 00671 PHOSPHORUS ORTHO (MG/L AS P)      150      0.220     <0.010      0.037*      0.080      0.050      0.030      0.020     <0.010
 00666 PHOSPHORUS DISS. (MG/L AS P)      113      0.340     <0.010      0.047*      0.080      0.050      0.040      0.030     <0.010
 00625 NITROGEN A+O TOT.(MG/L AS N)      240      2.400      0.040      0.608       1.200      0.700      0.530      0.400      0.270
 00665 PHOSPHORUS TOTAL (MG/L AS P)      240      1.000      0.020      0.139       0.350      0.160      0.110      0.072      0.040


 CFS          = CUBIC FEET PER SECOND                                 A+O          = AMMONIA PLUS ORGANIC
 US/CM @ 25C  = MICROSEIMENS PER CENTIMETER AT 25 DEGREES CELSIUS     N            = NITROGEN
 MG/L         = MILLIGRAMS PER LITER                                  NO2          = NITRITE
 CACO3        = CALCIUM CARBONATE                                     NO3          = NITRATE
 HCO3         = BICARBONATE                                           P            = PHOSPHORUS
 COLS./100 ML = COLONIES PER 100 MILLILITER                          
 %            = PERCENT                                              
 <            = LESS THAN

 Unless otherwise noted, all nutrients results are from filtered samples.

 *VALUE IS ESTIMATED BY USING A LOG-PROBABILITY REGRESSION
 #TO SEE COMPLETE NAME OF CONSTITUENTS, CLICK ON HIGHLIGHTED TEXT ABOVE