Data collected between 1993-1995 shows that
over 55% of Mobile Bay had bottom dissolved oxygen levels below 4 mg/l, and
30% showed levels below 2 mg/l, both representing substandard conditions.
In addition, portions of
the following rivers do not fully support their current or proposed water
use classifications because of nutrient enrichment and/or low dissolved
oxygen: Fowl River, Dog River, Lower Mobile River, Chickasaw Creek, Three
Mile Creek, and Tensaw River.
A substantial volume of data exists on the
levels of toxics and contaminated sediments in Mobile Bay. The EPA has
classified Mobile Bay as an “Area of Probable Concern” with regard to
sediment contamination, classifying sediments in some areas of Mobile Bay as
“poor” and acknowledging a great deal of concern about accumulated toxics.