Observations

Each record in the Observations table records a single measurement at a specified location and interval.

Field Name	Description	Data Type	Must be Populated?
Location	Unique Location ID	Text String	Yes
Interval	Text string used to identify the vertical interval of a measurement location	Text String	Yes
Date	Measurement date (may also include time)	Date - Time	Yes
Value	Measured value	Numeric - Floating Point	Yes
Formatted Value	Text string used in data table or posted values in place of numeric value from the Value field. Useful when you want reported value to appear in the identical format as reported by the lab. If using Excel to store data and the value in this field is a number, make sure to add a single apostrophe before the number so that Excel will treat it as a text string.	Text String	No
Constituent	Name of measured parameter	Text String	Yes
Media	Media in which measurement is made. There must be a record in Constituents table that corresponds to the constituent-media pair in every record of the Observations table.	Text String	Yes
Fraction	Indicates fraction, principally for metals, which can be measured as either total or dissolved	Text String	Yes
Flag	Qualifier flag as reported by lab. ND or < used to indicate a non-detect value in a post value or classed post plot.	Text String	No
Detection Limit	Detection limit value	Text String	No
Non-Detect	Boolean field indicating whether a row contains a non-detect value	Text String	No; presumed false if left null
Duplicate	Boolean field indicating whether a row contains the value of a field duplicate	Text String	No; presumed false if left null

The Location / Interval pair in an Observations record must correspond to a record in the Intervals data table. The Constituent / Media / Fraction must correspond to a record in the Constituents data table.

Non-Detects

Place TRUE in the non-detect field to indicate that the observation is a non-detect. Posted values and classed post plots will show "ND" as the value, unless you have elected to plot the mean value and at least one of the values is not a non-detect. In that circumstance, the mean will be calculated based on the value in the data field. Tabulated values will post "<" and the detection limit. If no detection limit has been specified, then it simply uses "ND". Contours, time history charts, pie charts and radial diagrams are generated using the numeric value in the Value field. You may elect to enter a value that is some fraction of the detection limit or simply enter a zero value.