Spatial Patterns in Water Quality Portal Data: Identifying and Addressing Gaps in Water Quality Monitoring and Reporting

The Water Quality Portal (WQP) is a collaborative service that integrates publicly available water quality data from three federal databases. It contains monitoring data from 2.6 million sites across all 50 US states, provided by over 400 agencies and organizations. Accordingly, the WQP offers a relatively comprehensive picture of the water quality monitoring activities in the United States. Robust and accessible water quality data can offer both insight and foresight that allow for efficient and timely responses by governments, service providers, and individuals to water quality concerns or threats. However, barriers can prevent water quality data providers from performing data collection, reporting, and integration, which leaves gaps in the availability and usability of water data.

Data from the WQP were analyzed to determine spatial patterns in monitoring coverage at the subwatershed scale. These patterns were integrated with population, race, ethnicity, and income data to determine what communities may be underserved by water quality monitoring. Trends varied by state and EPA region but were more strongly correlated with population density than with the anticipated factors of race, ethnicity, and income. Findings were compiled into a dashboard available on ArcGIS, and recommendations for policy and practice were developed for increasing the comprehensiveness and accessibility of water quality monitoring data.