CADDIS II

Abstract

The Causal Analysis/Diagnosis Decision Information System (CADDIS) is a web-based system that provides technical support for states, tribes and other users of the Office of Water's Stressor Identification Guidance. The Stressor Identification Guidance provides a rigorous and scientifically defensible method for determining the causes of biological impairments of aquatic ecosystems. It is being used by states as part of the TMDL process and is being applied to other impaired ecosystems such as Superfund sites. However, because of the complexity of causal relationships in ecosystems, and because the guidance includes a strength-of-evidence analysis which uses multiple causal considerations, the process is complex and information intensive. CADDIS helps users deal with that inherent complexity. The first version, CADDIS I, leads the user through the process, explains the steps, provides worksheets for completing the steps and illustrates each step using examples from a real case study. CADDIS I was released at the end of CY05.

In 2006, work had begun on CADDIS II, to provide more technical support including a conceptual model library, exposure-response information for common stressors, statistical tools for analyzing state monitoring data and links to data bases. CADDIS II is an ORD-wide effort, which will be completed in 2007.

CADDIS III, which is scheduled for 2009, will contain additional technical support and connectivity to resources that will help users determine the causes of biological impairments.