Surface Water - Alabama Department of Environmental Management

Methodology
evaluate streams throughout the basin. At each site, two field personnel completed a
riffle/run or glide/pool habitat assessment. The scores were averaged to obtain a final
habitat assessment score. One physical characterization sheet was filled out at each station.
Field data sheets used by ADEM are provided in Appendix L.
Habitat assessment guidelines: For comparison of habitat assessment results among
locations and stream types, the scores for each of the 5 major habitat parameters
(availability and quality of substrate and instream cover, sediment deposition, channel
morphology, bank structure and stability, and riparian zone protection) are summed and
then converted to percent of maximum score. With the exception of the Shale Hills (68f)
subecoregion, habitat assessment guidelines for each subecoregion are based on analysis of
ADEM's ecoregion reference site data collected within that subecoregion from 1991-2002.
Total scores equal to or greater than the 5 th percentile of reference site data were designated
as excellent; scores less than the 5 th percentile of reference site data were the remaining
three 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. Habitat 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).
AQUATIC MACROINVERTEBRATE ASSESSMENT
ADEM’s Multihabitat EPT (MB-EPT) screening method was used to collect aquatic
macroinvertebrates at 72 sites within the BWC Basin Group (Appendix F). An in-depth
description of the procedures used during an MB-EPT assessment can be found in ADEM
1999b. At each station, basic field parameters were measured and a stream flow was
estimated using an abbreviated cross-section flow measurement technique of 6-10
measurements (ADEM 2000c). A Global Positioning System (GPS) Unit was used to
determine the latitude and longitude of each station (if possible).
The MB-EPT method is an aquatic macroinvertebrate assessment technique used in
basinwide screening assessments that entails monitoring multiple sites over a large area.
The MB-EPT decreases collection effort and analysis time by processing the samples in the
field and focusing on the collection of the pollution-sensitive Ephemeroptera, Plecoptera,
and Trichoptera (EPT) taxa. This method was used to prioritize sub-watersheds most
impaired by NPS pollution. Once priority sub-watersheds are identified, more extensive
Tier II monitoring efforts are used to document and assess trends in water quality after
BMP implementation.
Collect samples from multiple habitats: The productive habitats at a site will differ
naturally between streams above and below the Fall Line. Coastal Plain streams, located
below the Fall Line, are usually low-gradient, “glide-pool” streams, characterized by sandy
substrates, a lack of riffle habitat, and meandering flows. Streams located above the Fall
Line are generally moderate-to-high gradient, “rifle-run” streams. Al available habitats
were sampled at each site. Habitats routinely sampled using this method include riffles,
leaf packs, rootbanks, snags/logs and rocks, and sand.
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