USGS National Water Quality Laboratory (NWQL) Data Revision for the Wastewater - Filtered Indicators method, dated March 19, 2018 - August 9, 2022

This revised dataset was created by the National Water Quality Laboratory (NWQL) in Lakewood, CO for the Wastewater Indicators (WWI) in filtered water by solid phase extraction, gas chromatography mass spectrometry (GCMS) method known as Lab Schedule 1433 and covers the dates from March 19, 2018 to August 9, 2022. All data for Lab Schedule 1433 are included from the listed date range and only a subset of this dataset were changed. An external audit of NWQL was preformed in 2022 and highlighted several important data quality issues which resulted in this dataset.