Quarterly Report 1: Bonnie Creek Watershed

              DRAFT Page 1 of 4
Quarterly Report 1
Bonnie Creek Watershed
Introduction
This is first in a series of quarterly reports to provide an update of Total Maximum Daily
Load (TMDL) development in the Bonnie Creek Watershed. The Illinois Environmental
Protection Agency (IEPA) is responsible for TMDL development and has contracted
with Camp Dresser & McKee (CDM) to complete TMDLs within this watershed. IEPA
plans to complete the TMDLs for this watershed within the next 14 months. This
quarterly report provides a brief description of what a TMDL is, the waterbodies that are
scheduled for TMDL development, the standards and targets the TMDLs will aim to
meet, public participation opportunities, project progress, and the next steps of the
process to complete.
TMDL Overview for Bonnie Creek Watershed
A TMDL is a calculation of the maximum amount of a pollutant that a water body can
receive and still meet water quality standards. TMDLs are a requirement of Section
303(d) of the Clean Water Act (CWA). To meet this requirement, IEPA must identify
water bodies not meeting water quality standards and then establish TMDLs for
restoration of water quality. IEPA lists water bodies not meeting water quality standards
every two years. This list is called the 303(d) list and water bodies on the list are then
targeted for TMDL development.
The TMDL goals and objectives for the Bonnie Creek Watershed include developing
TMDLs for all impaired water bodies within the watershed, describing all of the
necessary elements of the TMDL, developing an implementation plan for each TMDL,
and gaining public acceptance of the process. Following are the impaired water body
segments in the Bonnie Creek Watershed, which are also shown in Figure 1-1:
Impaired Water Bodies in Bonnie Creek Watershed
Water Body
Segment ID Water Body Name Size Potential Causes of Impairment
NCDC01 Bonnie Creek 10.01 miles Sulfates, other habitat alterations
NCD05 Galum Creek 13.21 miles Manganese, dissolved oxygen (DO), other
habitat alterations
NCD03 Galum Creek 4.48 miles Silver, sulfates, siltation, salinity/total
dissolved solids (TDS)/chlorides, other habitat
alterations
NCDB Little Galum Creek 13.36 miles Manganese, sulfates, salinity/TDS/chlorides,
other habitat alterations
The TMDL for each of the segments listed above will specify the following elements:
n Loading Capacity (LC) or the maximum amount of pollutant loading a water body
can receive without violating water quality standards