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Beautiful views of the Cahaba River
Cahaba River Project
–
Jefferson County Commission, AL
This
project is an ongoing study to gather data in support of
ongoing modeling efforts and the ultimate development of
a TMDL. The project included an initial study to
determine habitat types along the stream using EPA’s
Habitat Assessment protocols and determine the nutrient
/primary production relationships for the river. The
results from this study indicated that periphyton were
the main primary producers driving the system so
subsequent studies were planned to gather additional
data on the periphyton-nutrient relationships. The
principal objectives of the current investigation were
to determine the standing crop of periphyton in the
Cahaba River and develop a relationship between
periphyton biomass and nutrient concentrations and/or
nutrient loadings. Specifically, the individual tasks
to meet these objectives were:
• Characterize
periphyton biomass using several methods
• Monitor
alkaline phosphatase activity
• Establish
loading targets
• Develop
data for the dry weather nutrient TMDL.
These
studies are ongoing and will continue through 2003 with
the development of information to support the Nutrient
TMDL to be prepared by the State of Alabama.back to top
Total Maximum Daily Load (TMDL) Reviews – Illinois
Association of Wastewater Agencies (IAWA)
We were retained by the IAWA to
perform a review of the draft TMDLs and accompanying
Implementation Plans for the First and Second Round of
Illinois TMDLs. This review included the East Branch of
the DuPage River, Salt Creek, and the West Branch of the
DuPage River TMDLs. The draft organic enrichment/low
dissolved oxygen (OE/DO) TMDLs for the East
Branch DuPage and Salt Creek concluded that all of the
WWTPs in those watersheds would need to meet more
stringent effluent limits for carbonaceous biochemical
oxygen demand (CBOD) and ammonia-nitrogen of 5 mg/L and
1 mg/L, respectively. The goal of the review was to
evaluate and comment primarily on the IEPA’s TMDL
development process, as it was clear that these would
set a precedence for point source-related TMDLs
throughout the state.
Our scope of services also included
solicitation, review, and compilation of comments from
all IAWA members; assessment of the potential cost,
technical, and other implications to the WWTP
stakeholders in the watersheds; preparation of draft and
final comments to be submitted to the IEPA; presentation
of draft comments to the IAWA membership; and
participation in meetings between the IAWA and the IEPA.
The IAWA and other public comments
were considered by the IEPA, and the draft TMDLs were
revised to include formation of a watershed group and
implementation of monitoring and stream improvements
prior to requiring action by the WWTPs. The drafts have
been submitted to USEPA for approval. The IAWA intends
to continue working with the IEPA on these important
issues, with the goal of developing solutions that
provide the best water quality benefit for the most
reasonable cost.
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