STATION NAME:  MISSISSIPPI RIVER AT BELLE CHASSE
STATION NUMBER:  07374525            
STATE: LOUISIANA                 
COUNTY: PLAQUEMINES
                         



               STATISTICAL SUMMARY OF SELECTED WATER QUALITY DATA COLLECTED FROM AUG  1976 TO  AUG   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              180    1070000 177000.000 544772.500  955850.000 728500.000 507500.000 324500.000 204000.000
 00095 SPECIFIC CONDUCT US/CM @ 25C      156  27300.000    260.000    584.846     555.600    461.500    403.000    333.000    288.950
 00010 WATER TEMPERATUR (DEGREES)        153     31.500      1.500     18.399      30.000     26.500     19.500     11.000      5.500
 00400 PH, WH, FIELD    (STANDARD UNIT   156      8.100      6.700      7.540       8.000      7.800      7.600      7.300      7.000
 00410 ALKALINITY,WH,FE (MG/L AS CACO3   157    161.000     67.000    104.873     140.000    120.000    105.000     88.500     77.000
 00300 OXYGEN DISSOLVED (MG/L)           150     13.200      2.700      8.479      12.600     10.200      7.900      6.800      5.655
 00301 OXYGEN DIS. PERC % OF SATURATIO    83    109.000     37.000     87.325     102.800     94.000     89.000     80.000     70.200

 BACTERIA

 31625 COLIFORM FECAL 0 COLS./100 ML     142  17000.000      2.000    912.063    3300.000    825.000    310.000    147.500      6.050
 31673 FECAL STRPT KF A COLS./100 ML     139  40000.000      8.000    901.252    2300.000    760.000    280.000    120.000     31.000

 NUTRIENTS

 00631 NO2 + NO3 DISSOL (MG/L AS N)      127      2.800      0.030      1.424       2.500      1.700      1.400      1.100      0.500
 00608 NITROGEN AMMONIA (MG/L AS N)      127      2.200     <0.010      0.080*      0.240      0.080      0.040      0.030     <0.010
 00613 NITROGEN,NITRITE MG/L AS N         81      0.160     <0.010      0.020*      0.040      0.030      0.010     <0.010     <0.010
 00671 PHOSPHORUS ORTHO (MG/L AS P)      102      0.300      0.010      0.091       0.179      0.112      0.080      0.060      0.040
 00666 PHOSPHORUS DISS. (MG/L AS P)      145      0.300      0.000      0.103       0.220      0.130      0.100      0.060      0.040
 00625 NITROGEN A+O TOT. (MG/L AS N)      149      2.600      0.200      0.794       1.500      1.000      0.700      0.500      0.300
 00665 PHOSPHORUS TOTAL (MG/L AS P)      151      0.510      0.060      0.215       0.384      0.270      0.210      0.140      0.100

                                                                                                                         

 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
 COLS./100 ML = COLONIES PER 100 MILLILITER                           P            = PHOSPHORUS
 %            = 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