Skip to main content
U.S. flag

An official website of the United States government

TM22-04 Revision of results for ammonia by KONE for 817 samples analyzed January – March 2022

Detailed Description

In January 2022, an update was made in the National Water Quality Laboratory (NWQL) laboratory information management system (LIMS) that resulted in all censoring for ammonia by KONE to be disabled. Results that were less than the detection limit (DL) of 0.0200 mg/L ammonia (as nitrogen) or less than the reporting limit (RL) of 0.0400 mg/L ammonia (as nitrogen) were not correctly censored by the LIMS before release to Water-Quality Data Transfer (QWDX) and the National Water Information System (NWIS). Numerical results transferred from the instrument to the NWQL’s LIMS were computationally accurate, but were not replaced by the less-than symbol (“<”) and the DL for those results that were less than the detection limit. Numerical results that were less than the RL did not have the value qualifier code “n” (below the reporting level [0.0400 mg/L] but at or above the detection level [0.0200 mg/L]) applied. Affected results (817 results total) were not appropriately reported as either <0.0200 mg/L ammonia (as nitrogen; 510 results) or with the “n” value-qualifier code (307 results) because the censor function was inadvertently disabled. No other analytical lines were impacted. All other value-qualifier codes were correctly applied during this period.


Public Domain.