BEFORE THE ILLINOIS POLLUTION CONTROL BOARD
IN THE MATTER OF:
WATER QUALITY STANDARDS AND
EFFLUENT LIMITATIONS FOR THE
CHICAGO AREA WATERWAY SYSTEM
AND THE LOWER DES PLAINES RIVER:
PROPOSED AMENDMENTS TO 35 Ill.
Adm. Code Parts 301, 302, 303 and 304
R08-9
(Rulemaking - Water)
PRE-FILED TESTIMONY OF SUSAN O'CONNELL
My name is Susan O'Connell and I am a Supervising Civil Engineer in the Maintenance
& Operations Department at the District. I have a Bachelor of Science Degree in Civil
Engineering from the University of Illinois at Urbana-Champaign. I have worked at the District
as an engineer at varying levels of responsibility since 1992. In my current position, I manage
the District
'
s environmental permits
,
including the NPDES permits for the treatment plants.
These permits include monitoring
,
notification and reporting requirements for combined sewer
overflows, known as CSOs, within the District's Jurisdiction.
As part of the permit requirements, the District maintains a website which provides
information on CSOs and informs the public of the occurrence of CSOs. The public may also
sign up to receive direct notification of CSOs via email
.
The District also submits a quarterly
CSO monitoring report to the IEPA that documents the frequency and occurrence of CSOs
throughout the District
'
s jurisdiction for a three
-
month period
.
This reporting is accepted by the
IEPA in lieu of separate reporting by the local municipalities which have permitted CSO outfalls,
as the local municipalities do not have the means to monitor the outfalls themselves. The
District also conducts routine inspections
,
maintenance and cleaning activities of the District's
interceptor sewer system and associated appurtenances.
CSOs act as relief points when storm water runoff overwhelms the combined sewer
system.
During and after precipitation, CSOs to the waterway occur when the quantity of
combined flow of rainwater and sewage exceed the capacity of the treatment plants, the Tunnel
and Reservoir Plan {TARP} tunnels and the local sewer systems. The CSO outfalls act as a relief
point through which the excess flows can be transported, away from homes and businesses, into
the receiving waterway.
There are 78 miles of waterways within the District's jurisdiction. Approximately 73%
consist of manmade canals and 27% consist of natural streams, many of which have been heavily
modified, being deepened, straightened and widened, and are located in heavily urbanized areas.
There are 406 CSO points along the waterways within the District's jurisdiction. 199 of
these are owned by the city of Chicago; 35 are owned by the District and 40 local municipalities
own the remaining 172.
Within the CWS waterways that are the subject of the UAA, there are
255 CSO points. 178 of these are owned by the city of Chicago; 25 are owned by the District
and local municipalities own the remaining 52.
During 2005, there were a total of 33 days on which monitored CSO activity occurred; in
2006 and 2007, there were 65 and 42 days of monitored CSO activity, respectively. In 2005
there was an average of 10.7 CSO outfalls discharging on each day that CSO activity occurred.
In 2006 and 2007 there were an average of 12.3 and 13.6 CSO outfalls that discharged on each
day that monitored CSO activity occurred, respectively.
Included in the 406 CSO points, there are five pump stations which discharge combined
sewage into the waterways. The Racine Avenue Pump Station discharges into the South Fork of
the South Branch of the Chicago River; the North Branch Pump Station discharges into the
North Branch of the Chicago River; the 95`x' Street Purnp Station and the 122"' Street PS
2
discharge into the Calumet River, and the 125`x' Street Pump Station discharges into the Little
Calumet River. In 2005, 2006 and 2007, the Racine Avenue Pump Station discharged on 8, 20
and 20 days, respectively, while the corresponding volume pumped was 1.47, 5.37 and 5.31
billion gallons, respectively; the North Branch Pump Station discharged on 5, 19 and 16 days,
respectively, while the corresponding volume pumped was 0.614, 1.24, and 1.43 billion gallons,
respectively; the 95`x' Street Pump Station and the 122"d Street Pump Station did not discharge at
all during this period and the 125"' Street Pump Station discharged on three, four, and seven
days, respectively, while the corresponding volume pumped was 344, 496 and 672 million
gallons, respectively.
The official record of precipitation measured at O'Hare Airport for 2005, 2006 and 2007
is 24.09 inches, 41.93 inches and 35.80 inches, respectively. The official record of precipitation
measured at Midway Airport for 2005, 2006 and 2007 is 24.59 inches,
47.55
inches and 39.74
inches, respectively.
3
Respectfully submitted,
By:
Susan O'Connell
Attachment
Chicago Area Waterway System Combined Sewer
Overflows
4
Chicago Area Waterway System Combined Sewer Overflows
Legend
•
Chicago Combined Sewer Overflow
.
MWRD Combined Sewer Overflow
Other Combined Sewer Overflow
North Branch Chicago
River (NBCR)
from the Confluence with the
NSC to [he confluence with the
Chicago River
Chicago Sanitary and
Ship Canal (CSSC)
Calumet-Sag Channel (CSC)
North
Soul
Chic
h Branch of the
go River (SBCR)
;-ork (Bubbly Creek)
Calumet River (CaIR)
from O
'Brien Lock and Dam
to Lake
Michigan
Lake Calumet
Calumet River (CaIR)
from the Grand Calumet Rigor
to O'Brien Lock and Dam
Little Calumet River
(LCaIR)
Irom the jurIchon with the Grand Calumet
River to the Calumet
-Sag Channel
