NDAC 33-25-01 states that a sensitive groundwater area (SGWA) is defined as glacial drift aquifers with a DRASTIC score greater than or equal to 100 or as alluvial/aeolian deposit identified in Clayton's 1980 Geologic Map of North Dakota. The DRASTIC score surficial aquifers were updated in 2019, and again in 2021, necessitating an update to the SGWA dataset. This dataset includes all aqufiers identified with a general DRASTIC score greater than or equal to 100 and alluvial/aeolian sand and gravel deposits designated Qcs, Qod, QTou or QTu. Geologic units were dissolved into single units based on lithologic terra abbreviation.

For a complete description of DRASTIC methodology, refer to the separate DRASTIC layer and associated documentation, North Dakota Geographic Targeting System for Groundwater Monitoring(2019) for additional information.

This layer was updated in January 2021 to include 33 new sensitive aquifers that were scored in the "2021 Addendum to the 2019 North Dakota Geographic Targeting System For Groundwater Monitoring" (January 2021) and to match North Dakota State Water Commission aquifer delineations and names as of January 2021. The 2021 addendum report can be found online at https://deq.nd.gov/publications/wq/1_GW/GeoTargetSys/2021_GTS_Addendum.pdf(or navigate to the report by going to https://deq.nd.gov/WQ/Publications.aspx, select Groundwater Protection Program, Geographic Targeting System, 2019 Geographic Targeting System).