The 303(d) Listed Impaired Waters program system provides impaired water data and impaired water features reflecting river segments, lakes, and estuaries designated under Section 303(d) of the Clean Water Act. Each State will establish Total Maximum Daily Loads (TMDLs) for these waters. Note the CWA Section 303(d) list of impaired waters does not represent waters that are impaired but have an EPA-approved TMDL established, impaired waters for which other pollution control mechanisms are in place and expected to attain water quality standards, or waters impaired as a result of pollution and is not caused by a pollutant. Therefore, the "Impaired Waters" layers do not represent all impaired waters reported in a state's Integrated Report, but only the waters comprised of a state's approved 303(d) list. For more information regarding impaired waters refer to EPA's Integrated Reporting Guidance at: http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/guidance.cfm. 303(d) waterbodies are coded onto NHDPlus v2.1 flowline and waterbody features to create line, area, and point events. In addition to NHDPlus reach indexed data there may also be custom event data (point, line, or polygon) that are not associated with NHDPlus and are in an EPA standard format that is compatible with EPA's Reach Address Database. These custom features are used to represent locations of 303(d) waterbodies that are not represented well in NHDPlus. R2GIS selected out the Region 2 extent plus a one mile buffer from the National RAD 303d 05/01/2015 SNAPSHOT ESRI file geodatabase. R2GIS created two relationship classes on each of the three R2 RAD 303d SNAPSHOT 20150501 layers ( points, lines and areas). The relationships were built to the attgeo_303dcaussrce and rad_303d_sfid tables from the national RAD 303d 303d SNAPSHOT 20150501 database (selected on R2 extent plus one mile). Information on the attgeo_303dcaussrce table can be found at: 303(d) Listed Impaired Waters by Causes of Impairment and Probable Sources Location: http://www.epa.gov/waters/data/downloads.html#303(d) Listed Impaired Waters Entity Type Label: ATTGEO_303DCAUSSRCE Entity Type Definition: 303D Program Attributes Entity Type Definition Source: EPA ATTAINS. The rad_303d_sfid table provides information on the Start Date, Cycle Year, Event Count, Load Date, Update Date and area and length of features. Users should understand that the 05/01/2015 RAD 303d snapshot was made up of 303d reporting for the 2012 Cycle for NY, the 2010 cycle for NJ, mostly the 2012 cycle for PR and the 2012 cycle for VI. Since the one mile buffer used in the selection operation included hydrological features from CT, VT and PA, the Integrated Reporting cycles for this data ranges from 2002 (for PA) to 2012 for CT and VT.