CADDIS Volume 3: Examples & Applications

Caddis Case Studies Reports

These reports provide examples of how some assessors have developed and interpreted evidence to determine causes of biological impairments and in some cases have improved the quality of an ecosystem. They provide different examples of how to organize an assessment report, analyze data, and present results. These cases assess rivers and streams in five different states across the U.S.

The process for identifying causes of biological impairments continues to improve and was not intended to be interpreted in only one way. As a result you will note differences among the case studies. In some examples, comment boxes have been inserted to assist other users by suggesting alternative approaches that may be applied to their cases.

Click on the report covers to read more about each and to download the final reports.

Bogue Homo River, MI

The Bogue Homo River in Mississippi was initially listed as an impaired river based upon an evaluation of geographic information with no field measurements. Follow up biological monitoring of benthic macroinvertebrates by the Mississippi Department of Environmental Quality (MDEQ), confirmed that the stream was impaired - making this another good case study of causal assessment techniques.

Clear Fork, WV

The Clear Fork, West Virginia case study demonstrates that a watershed-wide causal assessment has several advantages for making analysis practical, defensible, and showing the relationships among interconnected waterbodies.

Floyd River, IA

The Little Floyd River, Iowa case study demonstrates that, even when there are many candidate causes and uncertainties are substantial, the probable causes of biological impairments can be determined with enough certainty to inform decision making to address environmental problems.

Touchet River, WA

The Touchet River, Washington causal assessment is the first application of the EPA Stressor Identification (SI) process to a long stretch of river or to the Northwest.

Willimantic River, CT

The Willimantic River, Connecticut case study demonstrates that a screening assessment can help to focus sampling for unknown episodic sources of toxic discharges. The removal of the discharge led to the removal of this segment of the Willimantic River from the 303(d) list of impaired waters.