Environmental Assessment
Causal Analysis of Biological Impairment in Long Creek, a Sandy-Bottomed Stream in Coastal Southern Maine (External Review Draft)
Archive disclaimer
Archived files are provided for reference purposes only. The file was current when produced, but is no longer maintained and may now be outdated. Persons with disabilities having difficulty accessing archived files may contact the NCEA Webmaster for assistance. Please visit http://epa.gov/ncea to access current information.
Report Information
This case study presents results from a complex assessment of a biologically impaired urbanized coastal watershed located primarily in South Portland, Maine, U.S.A., the Long Creek watershed. This assessment serves as an example implementation of U.S. Environmental Protection Agency Stressor Identification guidance. Four specific biological effects defining impairment and seven candidate causes of impairment were chosen and evaluated at three impaired sites along long Creek. Decreased dissolved oxygen, altered flow regime, decreased large woody debris, increased temperature, and increased toxicity due to ionic strength were identified as probable causes of impairment. The implications associated with interactions among probable causes are discussed in terms of this case study and causal assessment in general.
- by phone at: 703-347-8554
- by email at: ziegler.rick@epa.gov