[The assigned parameter/method codes reflect a coding of the data based on information from technical memorandum QW88_05 and records of national network protocols (memoranda QW84_16 and QW85_19). If an observation was unavailable for the indicated parameter code (column 4), the alternate parameter codes were searched for an available value according to the specified dates and parameter order. In the CD-ROM data sets, these values were assigned their corresponding parameter and method codes in column 4]
__________________________________________________________________________________________________
Constituent Dates Method of determination Parameter & Alternate
method code parameter codes
___________________________________________________________________________________________________
Data required by network protocols
___________________________________________________________________________________________________
Alkalinity Before Lab, fixed-endpoint titration1, 00417 A 00410, 00430, 00431,
10-01-84 unfiltered samples. 95430, 90410, 95410,
00421
Alkalinity 10-01-84 - Field, fixed-endpoint titration, 00410 A 00430, 00431
09-30-85 unfiltered samples.
Alkalinity 10-01-85 - Field, fixed-endpoint titration, 39036 A 00410, 00430, 00431
09-30-95 filtered samples.
Bicarbonate 10-01-85 - Field, incremental titration, 00453 B 99440, 00450
09-30-95 filtered samples.
Carbonate 10-01-85 - Field, incremental titration, 00452 B 99445, 00447
09-30-95 filtered samples.
___________________________________________________________________________________________________
Optional national network data
___________________________________________________________________________________________________
Alkalinity Before Field, incremental titration, 00419 B 99430
10-01-85 unfiltered samples.
Alkalinity 10-01-85 - Field, incremental titration, 39086 B 99430, 00419
09-30-95 filtered samples.
Bicarbonate Before Field, fixed-endpoint titration, 00440 A
10-01-85 unfiltered samples.
Bicarbonate 10-01-85 - Field, incremental titration, 00450 B 99440
09-30-95 unfiltered samples.
Carbonate Before Field, fixed-endpoint titration, 00445 A
10-01-85 unfiltered samples.
Carbonate 10-01-85 - Field, incremental titration, 00447 B 99445
09-30-95 unfiltered samples.
___________________________________________________________________________________________________
1 A limited number of field personnel may have conducted field determinations of
alkalinity by fixed-endpoint titration. These cases are coded as laboratory analyses.