Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock () or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

JavaScript appears to be disabled on this computer. Please click here to see any active alerts.

Resources for Planning Projects that Use Existing Data

Below are some links to help you get started.

Data Quality Assessment - Before existing data can be used, it will need to be assessed against its intended use.
Chapter 3 of the Guidance for Quality Assurance Project Plans (G-5) identifies elements to consider when planning projects that use existing data.
Checklist for Quality Concerns - Draft checklist and list of resources for evaluating secondary data.
EPA's Science Policy Council Assessment Factors - General Assessment Factors for Evaluating the Quality of Scientific and Technical Information
Software - For links to free software for performing data quality assessment, see Quality-Related Resources - Software. EPA has a site license for SAS for EPA employees - for information, see EPA SAS Support Home Page.

Resources for Planning Projects that Use Existing Data

Managing the Quality of Environmental Information