STATION NAME:  LOWER ATCHAFALAYA RIVER AT MORGAN CITY 
STATION NUMBER:  07381600            
STATE: LOUISIANA                  
COUNTY: ST MARY
  



               STATISTICAL SUMMARY OF SELECTED WATER QUALITY DATA COLLECTED FROM MAR  1956 TO  SEPT  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              259 692000.000  33600.000 206376.844  558000.000 268000.000 152000.000  98000.000  52600.000
 00095 SPECIFIC CONDUCT US/CM @ 25C      293    991.000    182.000    374.171     569.000    438.000    368.000    292.000    236.100
 00010 WATER TEMPERATUR (DEGREES)        254     32.000      5.000     19.331      30.000     27.000     20.000     12.000      6.500
 00400 PH, WH, FIELD    (STANDARD UNIT   305      8.300      6.200      7.591       8.100      7.800      7.600      7.400      6.930
 00410 ALKALINITY,WH,FE (MG/L AS CACO3   290    152.000     43.000     92.617     136.000    110.000     90.000     72.750     59.000
 00300 OXYGEN DISSOLVED (MG/L)           284     12.500      3.700      8.018      11.075      9.400      7.800      6.700      5.325
 00301 OXYGEN DIS. PERC % OF SATURATIO   129    110.000     48.000     83.481      98.000     92.000     85.000     77.000     60.500

 BACTERIA

 31625 COLIFORM FECAL 0 COLS./100 ML     195   4500.000      2.000    148.354     292.000    100.000     40.000     15.000      4.000
 31673 FECAL STRPT KF A COLS./100 ML     191   9000.000      2.000    408.592    2000.000    300.000     85.000     28.000      5.600

 NUTRIENTS

 00631 NO2 + NO3 DISSOL (MG/L AS N)      104      2.300      0.000      0.967       1.700      1.200      0.900      0.700      0.365
 00608 NITROGEN AMMONIA (MG/L AS N)      106      1.100     <0.010      0.068*      0.150      0.070      0.040      0.020     <0.010
 00613 NITROGEN,NITRITE MG/L AS N         67      0.060     <0.010      0.013*      0.030      0.020      0.010     <0.010     <0.010
 00671 PHOSPHORUS ORTHO (MG/L AS P)       90      0.130      0.010      0.049       0.094      0.060      0.040      0.040      0.020
 00666 PHOSPHORUS DISS. (MG/L AS P)      122      0.550      0.010      0.065       0.149      0.072      0.055      0.040      0.020
 00625 NITROGEN A+O TOT. (MG/L AS N)      131      2.200      0.300      0.817       1.400      1.000      0.780      0.600      0.400
 00665 PHOSPHORUS TOTAL (MG/L AS P)      282      2.700      0.040      0.225       0.457      0.250      0.170      0.110      0.070

                                                                                                                         
 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