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Water: Georeferencing

EPA's Assessment Database version 2 (ADB v.2)

What is the Assessment Database?

The Assessment Database (ADB v.2) is a relational database application for tracking water quality assessment results. All states assess their individual waterbodies for degree of designated use support (e.g., “fully supporting aquatic life; not supporting primary contact recreation”). If a waterbody’s uses are impaired, the stressors and sources of impairment are also determined (e.g., “causes/stressors are nutrients and sediment; sources are urban runoff and row crop agriculture”). The ADB v.2 is designed to make tracking and reporting this data accurate, straightforward and user- friendly for participating states, territories, tribes and basin commissions. It also enables users to meet the requirements of Section 305(b) of the Clean Water Act.

The design of the ADB v.2 eliminates spatial indeterminacy so that it can be linked to GIS and its data displayed in a meaningful way. The ADB v.2 accomplishes this by forcing all attributes of an entity to apply to that entity in its entirety.

Assessment Units

Assessment Units are the basic unit used by states to report their water quality to EPA for the Clean Water Act 305(b) Requirements. Assessment Units in the ADB v.2 are treated as homogeneous units. So any designated uses, use support ratings and associated causes and sources of impairment apply to the entire Assessment Unit.

How this applies to other databases

Any database can be used with GIS, as long it provides a surface water entity ID that can be linked to the GIS coverage data, and the data associated through this ID apply to the spatial entity in its entirety.

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