Null Data Reason Code
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Description
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A code explaining why no sample, blank, or quality assurance assessment value was reported.

Business Rules
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Must be a valid AQS Null Reason Code.

Must not be valued if the Sample Measurement is valued.

Must be valued if the Sample Value or Monitor Assessment is null/empty.

May not be valued on an RD record that also has an exclusion qualifier submitted.

Allowable values: https://aqs.epa.gov/aqsweb/documents/codetables/qualifiers.html