ContDataQC: Continuous Data Quality Control R Shiny Application

The ContDataQC R Shiny app is a free, open-source web-based tool that was developed to help water quality monitoring programs perform quality control (QC) procedures on continuous sensor data, used in long-term regional monitoring networks for streams and lakes. ContDataQC helps users speed up and standardize the QC process, reduce missed errors, and make full use of their sensor data. It has three main functions: generate quality control (QC) reports to detect anomalies and erroneous data values, merge QC'd data files from different time periods and generate time series plots and basic summary statistics.  ContDataQC is configured for temperature, water level, discharge, conductivity, dissolved oxygen (DO), pH, turbidity, chlorophyll-a and salinity data.  Users can change parameters and customize many of the requirements by editing the configuration file.  ContDataQC is available as a downloadable R package or via a weblink. If accessed via the URL, it does not require the installation of R software.   EPA Public Link for ContDataQC Web App:  https://shiny.epa.gov/ContDataQC/  

Impact/Purpose

Continuous sensors used to measure a variety of water quality parameters, such as temperature, water level, and dissolved oxygen (DO), at high frequencies (such as every 30-minutes) are becoming more affordable and accessible. The sensors capture temporal patterns and episodic events that may otherwise be missed if measurements can only be taken during a limited numbers of site visits. Now, with such large datasets, managing the data and performing quality control (QC) checks to detect anomalies and erroneous data values can be too difficult by hand, especially for users that lack prior experience working with sensors. Moreover, the iterative process of QC editing can be tedious and challenging.  ContDataQC was developed to help water quality monitoring programs improve the QC process, reduce missing errors, merge, and summarize continuous sensor data files in a standardized, more efficient way, to facilitate further analysis and sharing.

Citation

Leppo, E., J. Stamp, B. Bierwagen, AND M. Pennino. ContDataQC: Continuous Data Quality Control R Shiny Application. U.S. Environmental Protection Agency, Washington, DC, 2025. [DOI: 10.1016/j.softx.2025.102124]

• https://shiny.epa.gov/ContDataQC/

DOI: ContDataQC: Continuous Data Quality Control R Shiny Application