94-11 Where Policy and Water Quality Data Intersect: 303(d) Lists and Stream Impairment in the South Atlantic Gulf Watershed

Session: Geoscience and Water: How Geoscience Affects Water-Related Public Policy–Past, Present, and Future

Presenting Author:

Authors:

Abstract:

The Clean Water Act (CWA) of 1972 Section 303(d) requires that every state compile and submit biennial reports that document impaired water bodies, the water quality standards that define impairment, listing and delisting processes for impaired water bodies, statewide monitoring and assessment strategies, and plans that prioritize restoration of impaired waters. Essentially, these reports detail the history of impaired waters in the U.S., from initial listing, implemented restoration strategies, and finally to meeting water quality standards. However, the decentralized nature of 303(d) listing results in inconsistent data at both state and federal levels. Here, we have collected geospatial data from each state agency within the South Atlantic Gulf (LA, MS, AL, GA, FL, TN, SC, NC, and VA) for 303(d) lists from years 1998-2022. We found that geospatial data in this region is inconsistent across state-boundaries and through time. For example, data types varied across state boundaries, with MS, AL, GA, NC, TN, and VA representing data in linear segments, LA with watershed polygons, and SC with assessment points. Temporally, LA, AL, and VA had geospatial data for all targeted years (1998-2022), whereas GA, SC, and TN only had geospatial data available between 2008-2022. MS and NC data ranges were from 2004-2022 and 2006-2022, respectively.  Lastly, metadata associated with each file layer revealed varying amounts of detail; from GA’s tables listing all waters assessed, impaired, years monitored, water use classifications, and reasons for impairment, to early MS tables only listing a monitoring network ID and whether that stream was monitored for that assessment year. While the associated 303(d) reports contained complete data, many geospatial datasets did not include the same level of detail. Ultimately, regional spatiotemporal assessments of 303(d) listed waters are limited by their inconsistent geospatial data, making large-scale trend analyses at the intersection of policy and water quality challenging. This data summary identifies a need for more consistent and translational geospatial data for 303(d) Lists in the South Atlantic Gulf region, and for a comprehensive evaluation of 303(d) policies and their impact on water quality in the U.S.  

Geological Society of America Abstracts with Programs. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-9893

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