Surface Water - Alabama Department of Environmental Management

Methodology
Process samples in the field: After each habitat was sampled, the organic material was
elutriated from the inorganic material. The inorganic material was visually inspected for
organisms (esp. Trichoptera in stone cases). The organic matter was washed down, and
large debris was visually inspected and removed.
Collect pollution-sensitive taxa: Representative“EPT” organisms were removed from the
sample and preserved in a pre-labeled vial by habitat. The vials for each station were
returned to the lab in a Nalgene container labeled with the station number, date and time
collected, the names of the habitats collected at the station, and the initials of the team
member who processed the sample. The organisms were identified to family level in the
laboratory.
Field QA/QC procedures: At 10% of the field-picked stations, the debris remaining from
each habitat was preserved in wide-mouth containers and returned to the laboratory to
verify the removal of all EPT taxa and calculate the accuracy of the field-pick method.
Laboratory QA/QC procedures: Laboratory identifications for 10% of macroinvertebrate
samples were verified by a second qualified biologist. All data entered in the aquatic
macroinvertebrate mainframe Pace database are verified for accuracy.
Data analysis: The total number of pollution-sensitive EPT families collected from each
station was compared to EPT Index data collected from least-impaired ecoregional
reference reaches to evaluate the health of each stream reach. Each site was assessed as
excellent, good, fair, or poor based on the number of pollution-sensitive EPT families
collected (ADEM 2004a).
MB-EPT assessment guidelines: With the exception of the Shale Hills (68f) subecoregion,
MB-EPT assessment guidelines for each subecoregion are based on analysis of ADEM's
ecoregion reference site data collected within that subecoregion from 1991-2002. The
Excellent category was equal to 5th-95th percentile of reference site data; the remainder of
the categories were calculated as (low end of higher category minus (95th Percentile/4)).
Only one reference reach has been established within the Shale Hills subecoregion (68f),
which covers an area relatively impacted by mining activities and urban runoff from
Birmingham. MB-EPT assessment guidelines for 68f were calculated using reference data
collected in 68f and the 3 surrounding subecoregions: the Fall Line Hills (65i), the
Southern Limestone/Dolomite Valleys and Rolling Hills (67f), and the Dissected Plateau
(68e).
FISH IBI MULTI-HABITAT ASSESSMENT
Site selection: Thirty stations within the BWC were selected for the completion of fish
community Index of Biotic Integrity (IBI) assessments (Appendix F). Fish IBI assessments
were conducted at study reaches if impairment from sedimentation or habitat degradation
was suspected or if the aquatic macroinvertebrate assessment bordered between two
impairment categories.
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