Summary of the
TMDL Development Process for the Charleston
Side Channel Reservoir
Collect and analyze all existing data
Identify individuals and groups that are watershed
Prepare a Data Inventory and Water Quality Analysis
Plan and conduct public outreach meetings throughout
Select appropriate computer models for estimating
current and maximum pollutant loadings
Prepare Methodology for TMDL Development report
Conduct water quality modeling
Prepare report containing all data, modeling outputs,
recommended TMDL and implementation plan
Prepare final TMDL package for submission to EPA
for review and approval
( = Task completed)
Charleston Side Channel Reservoir TMDL
Progress Report #5
June 30, 2002
What pollutants do the TMDLs for the
Charleston Side Channel Reservoir address?
As part of the Section 303(d) listing process, the
Illinois Environmental Protection Agency (IEPA)
has identified the Charleston Side Channel
Reservoir (CSCR) as an impaired water. The
causes of impairment are phosphorus, nitrogen,
total suspended solids, and excessive algal
growth/chlorophyll a. The Clean Water Act and
U.S. Environmental Protection Agency (USEPA)
regulations require that Total Maximum Daily
Loads (TMDLs) be developed for waters on the
Section 303(d) lists. Illinois EPA is currently
developing TMDLs for pollutants that have
numeric water quality standards. Of the
pollutants impairing the CSCS, phosphorus is the
only one with a water quality standard.
What activities has IEPA accomplished to
The TMDL development process involves a
number of steps (see accompanying text box).
To date, IEPA and its consultant, Tetra Tech, Inc., have completed a number of the steps necessary to
generate TMDLs for the Charleston Side Channel Reservoir. Provided below is a detailed description of
• Held a public meeting at the Charleston High School on January 17, 2002, to inform
watershed residents and other stakeholders of the progress made to date in developing the
• Created a TMDL fact sheet that was handed out at the January 17, 2002 public meeting
• Contacted Eastern Illinois University to obtain information on best management practices that
have been installed since the early 1990s.
• Contacted NRCS offices in Champaign and Douglas Counties to update them on the status of
the TMDL and request information on agricultural practices in the watershed.
• Completed reservoir and watershed modeling to support TMDL development.
• Submitted a draft TMDL report for internal IEPA review in early June 2002. The report
presents the findings of the water quality and watershed modeling and includes
recommendations for how much loadings will need to be reduced.