Contaminated data that was likely caused by fouling or a worn wiper appears during the last 5 days of the chlorophyll series. To flag the data, the second QA option was enabled and the date/time limit set (marked by the blue line on 7/30/2005 06:15:00). The lower chart show data points remaining after this QA/QC step is complete. Two outliers appearing as spikes remain and will be removed in the next step.