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NATIONAL ASSESSMENT DATABASE (NAD)
Description:
Resource Purpose:The National Assessment Database stores State water quality assessments that are reported under Section 305(b) of the Clean Water Act. The data are stored by individual water quality assessments. Threatened, partially and not supporting waters also have data about the specific pollutants and potential sources of pollution. The database supports many of OW's programmatic requirements by tracking the types of pollutants impairing our nations waters, an indication of the sources of the pollution, and an estimate of the quantity of assessed waters across the U.S.
Legislation/Enabling Authority:CWA Section 305(b)
Supported Program:The 305(b) report to Congress, the 303(d) lists, IWI, economic benefit analysis for numerous proposed regulations including 303(d), CAFO/AFO/, Stormwater Phase 2.
Data Type:
Primary Data Type:
Monitoring
Regulatory, user checked two primary data types
Compliance
Geographical Data Stored By:
Other
State, HUC, and RF3 Reach - Not all States have had their assessments located to the RF3 level. Currently there are around 12 states with this level of resolution.
Measurement Methods:
Map interpolation and GPS
System Access Privileges:
Access Methods:
Resource Website
Direct
Update Methods:
FTP
Resources Accessible By:
Public
States
Regions
All EPA
EPA Branch
EPA Division
EPA Authorized
Other
Resources Updatable By:
States
EPA Authorized
Other
Prime Contractor
Data Collection:5 months
Range of Data Start:
19940101
Range of Data End:
19981231
Range of Data:
Data is collected biannually