Water Quality Indicators Data Review

Water Quality Indicators Background

The Water Quality Indicators (WQI) Project integrates and normalizes available ambient monitoring data to help EPA, state, and tribal staff better identify water quality problem areas. EPA currently publishes information about watersheds health based on assessments made by states under the Clean Water Act (CWA) 305(b) program. Those data reside in EPA ATTAINS and contain information about impaired watersheds (CWA 303(d)). Because a large number of watersheds have not yet been assessed, EPA began the WQI project to fill in data gaps. Specifically, statistics of ambient water data in the Water Quality Portal (Portals)Exit are generated and compared by the WQI project to national or ad hoc water quality criteria (currently only nutrient concentrations). EPA used data analytic methods to stratify the Portals data, and is now working to include data visualization tools that will help users display, better understand, and assess the data.  EPA envisions a wide-ranging set of uses for the data, including trend analysis, Total Maximum Daily Load (TMDL) development, and improved state and local permitting and compliance program administration. EPA is releasing a beta version of the database and methodology to receive feedback from interested individuals.

Material Being Released

• The WQI Dataset will be regularly updated and posted in this ECHO WQI downloads folder. See the file(s) named "ResultFileToEnd2Output##############.csv.gz", where the first eight #'s correspond to the refresh date of the file in the format yyyymmdd.
• Methodology Used to Derive WQI Data (beta) (DOCX) (17 pp, 67 K)
• Data Usability Dashboard: Water Quality Indicators Data Usability Improvement Project Dashboard

Requested Feedback

Please send feedback and questions to Rusty Wasem (wasem.russell@epa.gov). We are greatly appreciative of any and all feedback about the WQI dataset and methodology. We are especially interested in the following:

• How useful and understandable is the WQI dataset for identifying water quality areas of concern?  Do you suggest changes?
• Do you have concerns about data quality or suggestions on improving data quality?
• Do you have comments on the methodology used to derive the WQI dataset? For example, how we handle non-detects, missing units, subspecies combination, duplicate samples, depth, synonyms, etc. Do you have comments on the way the Technical Paper is written? Do you suggest changes?
• Could you suggest a priority list of improvements – additional or more sophisticated analyses?
• Do you have comments or suggestions on the data quality file or processes that can be used to improve data quality?
• Do you see the WQI as something that is useful for EPA to continue developing for other pollutants, and what aspects of the project are most useful to you? Do you suggest changes to the project?