| #D001 | | Underground Sources of Drinking Water (USDWs) | aquifers or parts of aquifers that supply a public water system or contain a sufficient quantity of groundwater to supply a public water system now or in the future. | high |
| #D002 | | Area of Review | The area where the injected plume and its associated pressure front may impact pore fluids. | medium |
| #D003 | | Notice of Deficiency (NOD) | A NOD identifies any required information that is missing from an application. | high |
| #D004 | | Request for Additional Information (RAI) | An RAI is a formal request from the permitting authority that additional information be provided to address questions that arise during the Technical Review of the application. | high |
| #D005 | | Source water collaboratives | local, state, and watershed-based partnerships working to protect sources of drinking water | high |
| #D006 | | Aquifer | An aquifer is an underground body of rock that contains and can transmit groundwater. | high |
| #D007 | | National Land Cover Database (NLCD) | serves as the definitive Landsat-based, 30-meter resolution, land cover database for the nation. | high |
| #D008 | | United States Geological Survey (USGS) Protected Areas Database of the United States (PAD-US) | the nation’s inventory of protected areas, including public open space and voluntarily provided, private protected areas. | high |
| #D009 | | Facility Registry Service (FRS) | provides location and attribute information on facilities, sites or places subject to environmental regulations or environmental interest. | high |
| #D010 | | Watershed Boundaries Dataset (WBD) | defines the areal extent or perimeter of surface water drainage areas formed by the terrain and other landscape characteristics. | high |
| #D011 | | National Hydrography Dataset (NHD) | represents the water drainage network of the United States with features such as rivers, streams, canals, lakes, ponds, coastline, dams, and streamgages. | high |
| #D012 | | 305(b) program | provides assessed water data and assessed water features for river segments, lakes, and estuaries designated under Section 305(b) of the Clean Water Act. | high |
| #D013 | | 303(d) Listed Impaired Waters program | provides impaired water data and impaired water features reflecting river segments, lakes, and estuaries designated under Section 303(d) of the Clean Water Act. | high |
| #D014 | | Tribal Areas | locations of American Indian Tribal lands in the lower 48 states. The areas include all lands associated with Federally recognized tribal entities--Federally recognized Reservations, Off-Reservation Trust Lands, and Census Oklahoma Tribal Statistical Areas. | high |
| #D015 | | Aquifer Exemption | The EPA exempts aquifers if the aquifer does not currently serve as a source of drinking water and will not serve as a source of drinking water in the future, based on certain criteria. | high |
| #D016 | | Multi-Resolution Land Characteristics (MRLC) Consortium | a partnership of Federal agencies led by the U.S. Geological Survey. | high |
| #D017 | | Grant Reporting and Tracking system (GRTS) | includes locational data for Clean Water Act Section 319 nonpoint source projects. | high |