Quality Assurance Process for National Lakes Assessment Surface Water Quality Parameters
The purpose of this code and resulting report is to provide a reproducible framework for quality assuring the National Lakes Assessment (NLA) surface water quality data. The data are inclusive of physical and chemical parameters as well as chlorophyll a. Data are evaluated for completeness and consistency while also providing an initial data quality check. The code includes checks for data completeness based on field logs, consistency in reporting units, consistency in data quality flags, checks for internal chemical validity, and provides a comprehensive set of bivariate plots to aid identifying data quality issues. The code produces a report in HTML format for interactive use and a tabular data file with all observations flagged by the process. The tabular file can then be used to annotate further investigations and follow-up actions, providing a record of the QA process. Additional background information on water quality validation is provided in the report appendix.