EIS-75-3833D
METROPOLITAN SANITARY DISTRICT
OF
GREATER CHICAGO
INlXf AJf AC
ENVIRONMEINl ACT STATEMENT
Prepared by:
US ENVIRONMENTAL PROTECTION AGENCY
REGION V
Chicago, Illinois
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DRAFT ENVIRONMENTAL IMPACT STATEMENT
FOR THE
METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
DES PLAINES - O'HARE CONVEYANCE SYSTEM
PREPARED BY
THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION V
CHICAGO, ILLINOIS
MARCH, 1975
yntal Pr-rtoctJ.cn
230 £_v..
C .r« '"'.""-.,
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fi-ivf IT* 1 T
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SUMMARY SHEET
1. Name of Action (Check one)
Administrative action (X)
Legislative action ( )
2. Brief description of action indicating what states (and counties) are
particularly affected.
The proposed projects consist of a system of conveyance tunnels
known as Upper Des Plaines Intercepting Sewers 20, 20A, 20B, 20C and
21, and drop shafts to intercept and convey wastewater from a 58.2
sq. mile service area in the Northwest region of the Metropolitan
Sanitary District of Greater Chicago to the proposed O'Hare Water
Reclamation Plant. (A separate EIS has been prepared on the O'Hare
Water Reclamation Plant). Upper Des Plaines Intercepting Sewers 20,
20A, and 21 will also intercept and convey flows from combined sewer
outfalls presently discharging to Weller's Creek and Feehanville Ditch
and will provide partial storage of the combined wastewater for later
treatment at the proposed O'Hare Water Reclamation Plant.
The O'Hare MSDGC service area consists of all or part of the
following communities within Cook County: Arlington Heights, Buffalo
Grove, Des Plaines, Elk Grove, Mount Prospect, Prospect Heights, Rolling
Meadows, and Wheeling, Illinois.
3. Summary of Environmental Impact and adverse environmental effects.
A. Short Term Impacts
1) Construction
a) Blasting
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Construction of the drop shaft access manholes and
parts of some tunnels will require blasting. To
minimize the impacts of bias ting particle velocities
will be restricted by matting and explosive charge
selection to values that prevent any physical damage
to surface structures and appropriate screening
of dust particles will be required.
b) Noise and Vibration
1) Blasting operations will be restricted to certain
hours of the day.
2) Heavy machinery, trucks, and other vehicles will
increase ambient noise levels in residential areas.
c) Water Quality and Quantity
1) Dewatering of tunnels will temporarily lower the
water table of the shallow aquifer. No effect on
local wells is anticipated.
2) Increased siltation in Higgins Creek may occur with
dewatering of the tunnels. (Presently, a half hour
detention time is being planned to minimize this
effect).
d) Air Quality
1) Dust from construction activities at surface sites
will be minimized by using hard paved surfaces and
dust control measures.
ii
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2) Operation of heavy construction equipment powered
by internal combustion engines will add to the air
pollutant loading. However, it is not anticipated
that this would result in a significant temporary
change in ambient air quality.
2) Operation Impacts
All conveyance tunnels will be grouted and lined with
concrete to minimize infiltration. In general, some slight
positive infiltration into the tunnels is planned to prevent
possible degradation of the groundwater supplies from exfil-
tration of combined sewage into the groundwater aquifers.
Based on analyses of storms of record, groundwater levels
and design parameters, occasional exfiltration into the ground-
water aquifers might occur. A groundwater well monitoring
program is planned to discover any problems which may develop.
B. Long Term Impacts
1) Combined sewage overflows to Weller's Creek and Feehanville
Ditch will be reduced from approximately 80 to 6 flows a year.
This would result in a 92% BOD reduction and 75% flow reduction
in combined sewage waste overflows to Weller's Creek and
Feehanville Ditch.
2) Relief of existing interceptors (which are presently overloaded
during wet weather) will also be provided.
3) No adverse long term impacts are anticipated.
iii
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4. Alternatives Considered:
a) Separation of combined sewers and construction of
conventional interceptors.
b) Collection and conveyance of combined overflows.
c) Collection,, conveyance and storage of combined overflows.
5. Irreversible and Irretrievable Commitment of Resources
a) Labor and energy expended in construction of the
proposed facilities and,
b) Capital cost of tunnels is not recoverable.
6. The following Federal,State and local agencies are being requested to
comment on this Draft Environmental Impact Statement:
Council on Environmental Quality
Department of Agriculture
Soil Conservation Service
U.S. Army Corps of Engineers
North Central Division
Chicago District
Department of Health, Education and Welfare
Department of Housing and Urban Development
Department of the Interior
Bureau of Outdoor Recreation
Fish and Wildlife Service
Geological Survey
Department of Transportation
Federal Aviation Administration
Energy Research and Development Administration
Argonne National Laboratory
Governor of Illinois
Illinois Institute for Environmental Quality
Illinois Environmental Protection Agency
Illinois Division of Waterways
Illinois Department of Conservation
Illinois Department of Public Health
Northeastern Illinois Planning Commission
Cook County Department of Environmental Control
IV
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Metropolitan Sanitary District of Greater Chicago
City of Des Plaines
Village of Elk Grove
Village of Arlington Heights
Village of Mount Prospect
Village of Palatine
Village of Wheeling
Others
7. Date Draft made available to:
a) Council on Environmental Quality - March, 1975
b) Public - March, 1975
Acknowledgement
Portions of this Environmental Impact Statement were taken directly
from the Environment Assessment prepared by the MSDGC (November, 1974),
and the'Tacilities Planning Study - MDSGC Overview Report" and"o'Hare
Facility Area" (January, 1975) also prepared by the MSDGC.
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TABLE OF CONTENTS
Summary Sheet i
Acknowledgement v
1. BACKGROUND 1-1
A. Identification of Grant Applicants 1-1
B. Description of the Proposed Actions 1-1
C. General and Specific Location of the Proposed Actions . . 1-2
D. Water Quality and Quantity Problems 1-3
E. Other Water Quality and Quantity Objectives 1-0
F. Costs and Financing 1-12
G. History of the Application 1-12
2. THE ENVIRONMENT WITHOUT THE PROPOSED ACTION 2-1
A. General 2-1
B. Detailed Description 2-3
3. ALTERNATIVES 3-1
A. Project Objectives 3-1
B. Constraints 3-1
C. Chronology of Plans and Studies 3-3
D. Alternatives 3-4
E. Comparative Analysis of Alternatives 3-6
F. Final Systems Screening 3-7
4. DESCRIPTION OF THE PROPOSED ACTIONS 4-1
A. Main Tunnel 4-1
B. Branch Tunnel 4-1
C. Sequencing of Tunnel Construction 4-2
D. Main Shaft and Drop Shafts 4-5
E. Access Manholes 4-9
F. Relationships to Existing Facilities and Other Projects . 4-9
5. ENVIRONMENTAL EFFECTS OF THE PROPOSED ACTIONS 5-1
A. Bedrock Geology 5-1
B. Soils and Surficial Geology 5-6
C. Hydrology 5-7
D. Land 5-16
E. Air Quality 5-17
F. Biology 5-19
G. Environmentally Sensitive Areas 5-19
H. Aesthetics 5-19
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TABLE OF CONTENTS
-2-
I. Noise and Vibration 5-20
J. No Action Alternative 5-20
K. Summary 5-21
L. Findings 5-22
6. FEDERAL/STATE AGENCY COMMENTS AND PUBLIC PARTICIPATION . . 6-1
7. SELECTED REFERENCES 7-1
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CHAPTER 1
BACKGROUND
A. Identification of Grant Applicant and Planners
The grant applicant for the proposed conveyance system projects
is the Metropolitan Sanitary District of Greater Chicago. The fa-
cilities Planning Report for the Metropolitan Sanitary District of
Greater Chicago is comprised of eight separate reports. These reports
consist of an overview report and individual reports for the seven
facility areas.
B. Description of the Proposed Actions
The Upper Des Plaines tunnel conveyance system consists of four
major elements. These are: the tunnels, eight drop shafts and one
main shaft, seventy access manholes, and nine monitoring wells. These
elements will be constructed as five separate projects. A brief
description of each is given below.
1. Connections and laterals: Weller's Creek, various locations,
Upper Des Plaines 20A (73-318-2S).
This project consists of constructing 22,000 linear feet of 20
foot diameter tunnel in rock at a depth of 160 feet; five drop
shafts; one main construction shaft, access manholes and mis-
cellaneous and appurtenant construction.
2. Connections and laterals: Weller's Creek, various locations, Upper
Des Plaines 20A (73-318-2S).
This project consists of constructing special diversion structures
to control and direct flow from existing interceptors and local
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combined sewer outfalls to the drops shafts and/or tunnels.
3. Earth tunnel: Waller's Creek, Mt. Prospect Road, Princeton
Street and Wolf Road, Upper Des Plaines 20B (73--319-2S).
This project consists of constructing 6,000 linear feet of five-
foot diameter earth tunnel at a depth of 60 feet; together with
manholes and connecting structures. This sewer will divert
sanitary sewage flows in the Upper Des Plaines 14A system from
the North Side Plant to the proposed O'Hare Water Reclamation
Plant.
4. Rock tunnels and drop shafts: Weller's Creek and Feehanville
Ditch, Lonnquist Boulevard and William Street, Upper Des Plaines
21 (73-320-2S).
This project consists of constructing 11,200 linear feet of
16-foot diameter deep rock level tunnel, 2,000 linear feet of
nine foot diameter deep rock level tunnel, three drop shafts,
special diversion structures, access manholes and miscellaneous
and appurtenant construction.
5. Intercepting sewer: Upper Des Plaines 20C (69-307-2S).
This project consists of a five foot diameter interceptor from a
junction structure at Wildwood Road and Oakton Street East along
Oakton Street for approximately 11,000 linear feet at a depth
of 40 feet terminating at drop shaft seven of the Upper Des Plaines
tunnel conveyance system. The sanitary sewage will flow to the
proposed O'Hare Water Reclamation Plant for treatment.
C. General and Specific Location of the Proposed Actions
The Upper Des Plaines Basin covers an area of 58.2 square miles
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(37,250 acres) in the northwest portion of the Metropolitan Sanitary
District, shown in Figures 1-1 and 1-2. This area is predominantly
residential in character. Growth of the area has been spurred by
several factors. Among the more significant of these is the proximity
of O'Hare Airport, the Northwest Tollway, the Tri-State Tollway, and
the Chicago and Northwestern Railway's tracks which bisect the basin
in a northwesterly direction.
The area includes the communities of Arlington Heights, Mount
Prospect, Prospect Heights, Wheeling, and a part of the City of Des
Plaines as well as newer urban developments such as Elk Grove Village,
Rolling Meadows and Buffalo Grove. As illustrated in Figure 1-1, the
boundaries encompass an area which lies generally West of the Des
Plaines River. Several major drainage courses traverse the basin in
a genera]ly East-West direction and empty into the Des Plaines River.
Two of the waterways are of concern, since they receive combined sewer
overflows even during low intensity storms. They are Waller's Creek
and Feehanville Ditch. No other waterways within the Upper Des Plaines
River Basin receive combined overflows.
Water Quality and Water Quantity Problems in the Area
1. Sources of Water Supply in the Service Area
There are three water supply sources to the service area:
a. Groundwater from shallow glacial-till Silurian
aquifer. The well records indicate that the majority
of wells in the shallow aquifer are private domestic
service with pumpout rates between 5 to 50 gpm.
1-3
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"L.J. \
CUPPER DES PLAINES
DRAINAGE BASIN1
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[Chicago
LEGEND
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FIGURE 1-1
METROPOLITAN SANITARY DISTRICT OF
GREATER CHICAGO GENERAL SERVICE AREA
1-4
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1-5
FIGURE X-2
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b. Groundwater from the deeper Cambrian-Ordivician
aquifer. The pumpage rate in the region of the
project has reportedly exceeded the sustained yield
of the Cambrian-Ordivician aquifer which has resulted
in a decline of the piezometric head averaging about
10-15 feet/year in the project area. The municipal
and industrial pumpage appears to be from the deep
aquifer which estimated on population, may have
amounted to 20 to 25 MGD for 1970 in the project area.
c. Surface water from Lake Michigan. It is anticipated
that larger quantises of Lake Michigan water will
be made available to municipalities outside of
Chicago in the future to limit the pumpage rates to
the practical sustained yield in the project area.
Des Plaines presently obtains 70 percent of its
water from Lake Michigan through the City of Chicago
System.
For a more detailed discussion of water supply issues, see REGIONAL
WATER SUPPLY REPORT //8, Northeastern Illinois Planning Commission,
September, 1974.
2. Sanitary and Combined Sewers
Approximately 5,000 acres of the 37,250 acres in the
Upper Des Plaines Basin are expected to remain undeveloped
and unsewered. This 5,000 acre area consists of special
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use land such as the Ned Brown Forest Preserve, cemeteries
and the U. S. Military Reservations. Of the remaining
32,250 acres, 26,298 acres are presently (or will be in
the near future) serviced by separate sanitary and storm
sewers, and 5,952 acres are serviced by combined sewers.
In addition, there are 1,370 acres of separate sewered
areas that connect directly to the combined sewer systems
in such a way that the flows cannot be physically separated
except through extensive and costly construction. Figure
1-3 illustrates the area contributing combined overflows
to the Upper Des Plaines project. Those areas indicated
are: 1) the combined sewered area, 2) the separated sewer
area contributing to the project, and 3) the boundaries
of all sewered areas contributing to Weller's Creek and
Feehanville Ditch. There are about 5,448 acres within the
boundary of the sewered area contributing to Weller's
Creek and Feehanville Ditch that are served by separate
sewer systems. The storm flows from these areas will
continue to discharge directly into Weller's Creek and
Feehanville Ditch and are not a part of the proposed
project.
At present all sanitary sewage, and the combined
sewage in the O'Hare Service Area, except for overflows,
is finding its way into Metropolitan Sanitary District
interceptors through regulated control structures, and is
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W ' Y wii\
tl_,i-BkiK,
f
?« i
.,.JK*r«$K : " SEPARATED AREAS
'^JfSiy/V;' CONTRIBUTING TO SYSTEM
Illlllllll COMBINED SS:WERED AREA
FIGURE 1-3
COMBINED-SEWER SERVICE AREA
1-8
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diverted through existing interceptors to the MSDGC's
North Side Sewage Treatment Works for treatment.
During wet weather, the North Side Sewage Treatment Plant
is presently overloaded and existing interceptors are
approaching capacity. In addition there is frequent dis-
charge (average: 80 per year) of combined sewage to Weller's
Creek and Feehanville Ditch creating an unsightly, odorous
condition, as well as a potential health hazard. This un-
treated sewage then flows into the Des Plaines River.
Weller's Creek serves as the main conveyance facility for
the discharge from combined sewers serving the watershed.
Backup in the combined sewers is the primary cause for
basement flooding. Some homes are affected in this manner
from almost all rainfalls in the watershed. Combined
backup will flood approximately 100 basements for the 5-
to 10-year storm event. Street flooding will begin to appear
for this same storm event.
Overbank flooding does not occur until the 25-30-year
storm event occurs.
The water quality standards that determine the effluent
parameters for the proposed Wastewater Reclamation Plant
are found in the WATER POLLUTION REGULATIONS OF ILLINOIS.
E. Water Quality & Water Quantity Objectives in the Area Other Than
Solution of Preceding Problems
The following programs are relevant:
1. The Federal Water Pollution Control Act Amendments of 1972
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(P.L. 92-500) require:
a. Secondary treatment of wastes for municipal
sewage and best practicable treatment for industrial
discharges by July 1, 1977.
b. Best practicable waste treatment technology for
municipal wastes and best available treatment
for industrial wastes by July 1, 1983.
c. All point-sources discharges require a permit
under the NPDES program (National Pollutant
Discharge Elimination System). The NPDES permit
states the allowable waste loading and flow volume
that can be discharged to a receiving stream, lake
or ocean.
2. The National Flood Insurance Act of 1968 requires the desig-
nation of flood-prone areas in the United States and partici-
pation by the appropriate communities and homeowners to
qualify for national flood insurance protection. The flood-
prone areas in the O'Hare Service Area have been determined
for the 100 year storm event and these maps, except for the
Arlington Heights quadrangle, are available from the North-
eastern Illinois Planning Commission (NIPC).
3. The Flood Control Activities planned by MSDGC for the O'Hare
Service Area are discussed in Appendix A.
4. The MSDGC Tunnel and Reservoir Plan (TARP) for control of
flood and pollution problems due to combined sewer discharges
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in the general service area of the MSDGC is described in
Appendix B. The U.S. Senate Committe on Public Works
(93rd Congress, 1st session) directed the Army Corps of
Engineers to determine the Federal interest in participating
in the TARP program. Since the Corps viewed any potential
Federal participation to be a significant Federal action,
they determined that part of their response in determining
Federal interest should be the preparation of an Environ-
mental Impact Statement. Prior to the issuance of a draft
EIS in November 1973, an Environmental Assessment (EA) on
the TARP program was prepared. USEPA participated in
discussions during the preparation of that EA and made
suggestions with respect to potential environmental impacts
to be addressed. A public hearing on the TARP EA was held
July 26, 1973 and discussion was presented relating to the
alternative plans presented. The O'Hare Service Area, since
it contains some combined sewers, was considered in all
alternative TARP plans. In some TARP alternatives, the O'Hare
service area was sewered by tunnels only, with wastewater
treatment occurring at the MSD North Side STP or WSW (Stickney)
STP. Although this alternative was considered, it was not
supported in other engineering studies for the O'Hare Service
Area. These reports support a WRP for the O'Hare Service
Area and are discussed in Appendix C.
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USEPA has determined that the O'Hare Service Area
can be separated from the TARP program with respect to
building the treatment plant and the conveyance system to
it. No determination has been made with respect to building
a combined sewage overflow reservoir or interconnecting
the proposed conveyance system to the lower Des Plaines
TARP system.
F. Costs and Financing
The project cost for the O'Hare conveyance system is approxi-
mately $36.5 million. This estimate includes the cost of all
physical elements of tunnels, interceptors, and connecting
structures together with a 20 percent factor for contingencies.
Financing of the conveyance facilities portion of the project
would be through local and Federal funds. Twenty-five percent,
$9.1 million, of the project would be financed from an existing
$380 million MSDGC bond issue with the remaining 75 percent,
$27.4 million, from Federal grants.
G. History of the Application
Most MSDGC projects, proposed for the O'Hare Service Basin
have been given a priority ranking of 31 by the Illinois Environ-
mental Protection Agency (IEPA). The infiltration/inflow analysis
for the service basin was transmitted to the IEPA on January 31, 1974.
It has since been revised by the MSDGC and is under review by the
IEPA. An informal review is also presently underway by this agency.
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CHAPTER 2
THE ENVIRONMENT WITHOUT THE PROPOSED ACTION
A. General
The Upper DesPlaines Area Service Basin, under the jurisdiction
of the Metropolitan Sanitary District of Greater Chicago (MSDGC),
is located in Northern Cook County, Illinois, within the Chicago
SMSA (Standard Metropolitan Statistical Area).
The service area is a 58.2 square mile in the northwest
region of the MSDGC's total jurisdiction of 860 square miles within
the County.
The service area has experienced rapid population growth
during the last 15 years. The population for Northeastern Illinois
increased 12.2% from 1960 to 1970. The following figures
for communities to be served by the proposed water reclamation
plant (WRP) and tunnel system indicate this growth.
Community 1960 1970 % change
Arlington Heights 27,878 64,884 132.7
Buffalo Grove 1,492 11,799 690.8
DesPlaines 34,886 57,239 64.1
Elk Grove 6,608 21,866 231
Mount Prospect 18,906 34,995 85.1
Prospect Heights . . . 13,333 . . .
Rolling Meadows 10,879 19,178 76.3
Wheeling 7,169 14,746 105.7
(All figures from U.S. Dept. of Commerce, Bureau of the Census,
publication PC(1)A15-I11.)
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Figure 1-2 indicates the service area and location of the
communities. The service area is predominantly residential in
character. The 1970 population for the area was 223,000,. Growth
in the area has been encouraged by several factors including the
1
presence of O'Hare Airport, Northwest Tollway, Tri-State Tollway
and the Northwestern Railroad line. The area is 60% developed and
construction of light industrial facilities and residential units
(both single family and multi-family) is ongoing to date.
The economic condition of the area's population is above the
Chicago SMSA median family income of $11,841 and State of Illinois
Median family income of $10,959.
1970 census figures indicate the following Median family incomes:
Arlington Heights $17,034
Buffalo Grove $14,833
DesPlaines $14,056
Elk Grove Village $14,155
Mount Prospect $16,503
Prospect Heights $15,992
Rolling Meadows $13,343
Wheeling $13,398
These figures indicate a healthy economic situation within the service
area.
Few environmentally sensitive areas are within the service area.
A small portion of the Cook County Forest Preserve District's Ned
Brown Preserve of 3,600 acres occupies the western portion of the
area. The Forest Preserve District's holdings along the DesPlaines
River are located in the eastern portion of the area.
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B. Detailed Description
1. Climate
The continental climate of the service area has relatively warm
summers and cold winters, with frequent short fluctuations in
temperature, humidity, cloudiness, and wind direction. Temperatures
of 96°F. or greater occur in about half of the summers while about
half of the winters may have low extremes of -15°F. The mean annual
temperature is 49 F. Precipitation averages 33 inches per year,
with about 10% of this occuring as snow. Summer rainfall is
unevenly distributed in intense local showers while precipitation
in the fall, winter, and spring tends to be more uniform over large
areas. Winds are most commonly from the southwest and the northwest,
on an annual basis. Tornadoes occur in Northern Illinois and are
most prevalent in March, April, May, and June. Other periodic hazards
include severe thunderstorms, hail, and ice storms. Fog is Infrequent
in the Chicago area. Detailed climatological data are available from
O'Hare International Airport, at the south end of the study area.
2. Topography
The service area is 58.2 square miles, sloping from about 700
feet above sea level at the western boundary to about 625 feet above
sea level at the Des Plaines River, 6 1/2 miles to the east.
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Landforms are gently rolling, with slight vertical relief. Most
of the study area has undergone the transition from a region of
small towns and farm land to an extensive suburban area of single
family homes, apartments, and commercial and industrial development.
3. Geology
The project area is underlain by three geologic systems.
The stratigraphic sequence is the Quarternary System, the Silurian
System and the Ordovician System. (See Figures 2-1 and 2-2).
The Quarternary System is composed solely of material from the
Pleistocene series. The formations contained within the series are
the Wadsworth and Wedron. The main constituents of both are clayey
silts with sand lenses orginating from glacial deposits.
The Silurian System lies under the Quarternary System and
contains material originating from the Niagaran and Alexandrian
series. The Niagaran series contains the Racine, Waukesha and Joliet
formations. The Racine and Waukesha formations are composed of
argillaceous fine grained dolomite while the Joliet formation is a
lighter gray dolomite. The Kankakee and Edgewood formations comprise
the Alexandrian Series. Dolomite is also the major portion of these
formations ranging from fine to shaly in texture.
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System
QUATERNARY
1 SILURIAN
V
ORDOVICIAN
Series
\ i
/ Pleistocene 3
( l
Niogoron
\
Alexandrian
Cincinnotian
t
Formation/Member
WADSWORTH
MEMBER
WEDRON
FORMATION
RACINE
(0 -300')
(WAUKESHA)
(0-20')
JOLIET
(4O-7O)
Ro-neo
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not
desert
Description
Till and outwosh deposits. Clayey silt with
sand lenses. (Gravel lenses possible but not
probable - described in soils report )
Bouldery till, clayey silt with sand lenses,
grovel, boulders common near base and at
unconformity. (Described in soils report.)
Gray- brown, orgillaceous,hne grained,
thin bedded dolomite containing ivefs
of pure, gray, massive, vuggy, dolomite.
Gray, fine groined, silly dolomite.
(Generally absent in northern area )
Light gray, pure, porous dolomite
Light gray, silty,very fine groined dolomite
Red or greenish gray dolomite and
interbedded shale
Light brown, fine grained dolomite with
prominent wavy cloy partings.
Brown to gray sholey dolomite.
(Cherty near top. Not recognized in
project area )
Oolite and red shale^GenenjIly ^absent )
Oolite and red shale. (Generally absent)
Green to brown fossil iferous mud stone
t>«tf
FIGURE 2-1
STRATIGRAPHIC SEQUENCE
-------
ROCK TUNNELS
Surface
EARTH TUNNELS
-Surface
TrlUffn^.
50
OVERBURDEN^
+6O
ESTIMATED PREDOMINANTLY
PIEZOMETRIC
HEAD UNDER CLAYS AND SILTS
MAXIMUM
SURCHARGED
CONDITIONS
RANGE OF PREVAILING
GROUND WATER LEVELS
AT TIME OF SUB-SURFACE
INVESTIGATION
CONC. LINING
25
50
PROPOSED 5'
TUNNELS EARTH
2
\
o
>-
h-
o
o
CO
<
o
I
o
-IOO
WAN'KAKEE
r-BRAINARD
-SHALE
TOP OF ROCK
GENERALIZED STRATIGRAPHIC SECTIONS
FIGURE 2-2
2-6
75
100
125
::::::::::::::::::::::::::::::!
::::::::::::::=::::::::::::::4
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9RH
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150
175
200
-------
The final system is the Ordovician, composed of the Cincinnation
series which has two formations; the NEDA and Brainard Shale Red
shale and fossiliferous raudstone comprise the majority of these
formations.
The above discussion emcorapases approximately the first eight
hundred feet of earth. There are two main aquifers contained in
the above mentioned geologic structures. They lie in the Silurian
and Ordivician Systems.
The Silurian aquifer has an average depth of 108 to 205 feet.
It is composed mainly of glacial till material. The uppermost
material, in the area of access tunnels and work shafts is slightly
more porous than that surrounding the rock tunnel. The coefficient
of permeability (C ) of the glacial till is 10~6 to 10~8 cm/sec.
Because of the low C there will be no significant release of water
to the tunnel through seepage. Any seepage that will occur results
from openings primarily in the form of cracks and joints in the rock.
The location of inflows in this case can easily be located after
excavation, particularly within the machine bored section of the tunnel
and may be appropriatly grouted. Another source of inflow may occur
during the boring of work shafts or access tunnels. The inflow will
originate from ground water seepage, to the upper portions of the
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shaft and tunnels. This seepage may also be arrested by the
use of grouting techniques. Within the formation there exists
sand gravei pockets which hold limited amounts of water. If
they are encountered by construction, the water may be released
to the tunnel. These quantities of water appear to be extremely
limited and are not known to be used as potable water supply
sources.
As an overall view it is anticipated that the drawdown of the
water supply aquifier during operation of the facility will be
virtually zero. It is expected that grouting will reduce the
groundwater flow into the tunnels to less than 300 gpm over the
total length of tunnels based on the results obtained from previous
projects. Tunnel lining which is planned, will further reduce
inflows.
Since the tunneling lies within the glacial till-Silurian
system and concurrently within the Silurian aquifier area, a discussion
of the Ordivician aquifier will be left to the water supply section
of this statement. Groundwater and surface water recharge of the
aquif ers will also be addressed in that section. A more complete
discussion of the bedrock geology can be found in Appendix D.
-------
4. Soils
The soils of the study area have developed from glacial parent
materials, under prairie and transitional (prairie to woodland)
vegetation. Alluvial soils have developed along stream floodplains.
Most soils generally have fairly slow permeabilities and high
seasonal water tables, resulting in poor drainage. Despite the
slow drainage erosion control is desirable to avoid soil loss
and the sedimentation of streams.
5. Hydrology
A. Surface Water
The study area is located in the drainage basin of the DesPlalnes
River. Several small streams originate in the study area and flow
eastward to join the DesPlaines River. The streams and their drainage
basins have been and are being modified as the area develops. Named
tributaries of the project area include: Buffalo Creek and Wheeling
Drainage Ditch; McDonald Creek; Weller's Creek and Weller's Drainage
Ditch; Higgins and Willow Creek; and Feehanville Ditch. All of these
watercourses have a 7-day once in 10-year low flow of zero. The
natural drainage boundaries for Weller's Creek and Feehanville Ditch
are indicated in Figure 2-3.
2-9
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rwoisa^K^
:***
^n
. Yo'f
fef
, <> / /d
^
^
v^c i
s*??'",!
"-- -4*^
i.* /fa',
f> *f fy f, -
i / '"s
^^}
! * '
i.- *, "
Nb
1 - ft.
i r_.T:.,,.:=^ j
' ' ^n.-,,.^..-.U'.^i':L
TTfT ^ r ':y;vi"~r; .. ^/v ->v
FIGURE 2-3
NATURAL DRAINAGE BOUNDARIES
WELLER'S CREEK AND FEEHANVILLE DITCH
2-10
-------
Weller's Creek, which has a total length of approximately 6.5
miles, is joined by a number of smaller tributaries and drains an
area of approximately 10,780 acres. Portions of this stream have
been relocated, some areas have been channelized and other areas
are in underground conduits. Modifications of dendritic extremities
have been most extensive as many have been eliminated by developments,
and other portions are underground. The vast majority of this
drainage basin has been urbanized.
Feehanville Ditch extends for approximately 2.5 miles and
drains an area of approximately 1,990 acres. This watercourse
and its drainage basin have been substantially modified by urbani-
zation. The headwaters of Feehanville Ditch are underground as
is a portion north of Maryville Academy, and a large portion of
the stream has been channelized.
Higgins Creek is about five miles in length and drains
approximately 5,000 acres before joining Willow Creek at a point
approximately three to three and a half miles upstream from the
Des Plaines River. The majority of the Higgins Creek area is
highly urbanized with some industrial and agricultural uses.
Higgins Creek has been filled, relocated and channelized in
several places.
The flow rates of Weller's Creek at Golf Road have been
monitored by the United States Geological Survey. The rates of
2-11
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flow are as follows: two-year flood - 520 cfs; five-year flood -
900 cfs; ten-year flood - 1,200 cfs; 25-year flood - 1,600 cfs;
LOO-year flood - 2,400 cfs. No data are available for the smaller
drainage basin of Feehanville Ditch.
The water quality of Weller's Creek and Feehanville Ditch
has drastically deteriorated with the increasing urbanization of
the respective drainage basins. Computer model simulation esti-
mated that during the 21-year period from 1949 to 1969, effluents
from the combined sewers of this area have overflowed into the
above streams 1,660 times discharging a total 140,000 acre-feet
of sewage which had contained 146,000,000 pounds of suspended
solids, and created a BOD (Biological Oxygen Demand) of 20,200,000
pounds.
The United States Geological Survey estimated the 10, 50,
100 and 500-year flow rate of Higgins Creek at Mount Prospect
Road to be 840,1,250, 1,650 and 2,180 cfs respectively. The
water quality in Higgins Creek is poor and is probably below
State standards. Existing urban activities contribute polluted
stormwater runoff to the natural flow of Higgins Creek probably
adding significant quantities of inorganic and organic pollutants.
The Illinois Environmental Protection Agency sampled
Weller's Creek during 1971. Table 2-1 compares many parameters
2-12
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WATER QUALITY DATA OF WELLER'S CREEK*
COMPARED TO STATE STANDARDS**
Table 2-1
Weller's Creek
Unit
State Standards
Water
Temperature (F°)
Number of Analyses 10
Maximum Value 75
Minimum Value 36
Average Value 55
Field Dissolved Oxygen (mg/1)
Number of Analyses 8
Maximum Value 8.5
Minimum Value 0.0
Average Value 2.9
Turbidity (JTU)
Number of Analyses 10
Maximum Value 800
Minimum Value 17
Average Value 102
The maximum temperature rise
above natural temperature
shall not exceed 5°F.
January 60°F. Maximum
August 90°F. Maximum
Not less than 6.0 mg/1 during
at least 16 hours of any 24
hour period,nor less than
5.0 mg/1 at any time.
Waters shall be free from un-
natural sludge or bottom
deposits, floating debris,
visible oil, odor, unnatural
plant or alga growth, or un-
natural odor or turbidity.
1,000 mg/1
Total Solids (Dissolved) (mg/1)
Number of Analyses 10
Maximum Value 1,309
Minimum Value 234
Average Value 701
* Water Quality Network, 1971, Summary of Data, Volume 2.
State of Illinois, Environmental Protection Agency.
** Illinois Pollution Control Board, Rules and Regulations, Chapter 3,
Water Pollution. July 1973.
2-13
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WATER QUALITY DATA OF WELLER'S CREEK
COMPARED TO STATE STANDARDS
Table 2-1 (continued)
Waller's Creek Unit
Fecal Streptococcus (per 100 ml)
Number of Analyses 3
Maximum Value 37,000
Minimum Value 270
Average Value 15,090
Coliform (per 100 ml)
Number of Analyses 5
Maximum Value 700,000
Minimum Value 13,000
Average Value 188,600
Chemical Oxygen Demand (mg/1)
Number of Analyses 10
Maximum Value 120
Minimum Value 22
Average Value 49
Biochemical Oxygen Demand (mg/1)
Number of Analyses 1
Maximum Value 5
Minimum Value 5
Average Value 5
State Standards
No State standards
No State standards
No State standards
No State standards
2-14
-------
WATER QUALITY DATA OF WELLER'S CREEK
COMPARED TO STATE STANDARDS
Table 2-1 (continued)
Weller's Creek
Unit
State Standards
Number of Analyses
Maximum Value
Minimum Value
Average Value
Total Phosphate (mg/1 of
Number of Analyses
Maximum Value
Minimum Value
Average Value
Ammonia (mg/1 of N)
Number of Analyses
Maximum Value
Minimum Value
Average Value
Chloride (mg/1)
Number of Analyses
Maximum Value
Minimum Value
Average Value
10
8 . 3
7.3
7 . 7
10
4.2
0 . 3
1.7
5
3.8
0.6
2.1
10
395
70
181
Shall be within the range of
6.5 - 9.0.
Phosphorus as P shall not
exceed 0.05 mg/1.
Shall not exceed 1.5 mg/1
Shall not exceed 500 mg/1
2-15
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WATER QUALITY DATA OF WELLER'S CREEK
COMPARED TO STATE STANDARDS
Table 2-1 (continued)
Weller's Creek Unit
Fluoride (mg/1)
Number of Analyses 7
Maximum Value 0.6
Minimum Value 0.3
Average Value 0.4
Iron (Total) (mg/1)
Number of Analyses 1
Maximum Value 0.1
Minimum Value 0.1
Average Value O.I
Phenols (mg/1)
Number of Analyses 3
Maximum Value 70
Minimum Value 0
Average Value 23
Sulfate (mg/1)
Number of Analyses 10
Maximum Value 215
Minimum Value 42
Average Value 99
Fecal Coliforms (per 100 ml)
Number of Analyses 10
Maximum Value 80,000
Minimum Value 400
Average Value 18,180
State Standards
Shall not exceed 1.4 mg/1
Shall not exceed 1.0 mg/1
Shall not exceed 0.1 mg/1
Shall not exceed 500 mg/1
Based on a minimum of 5
samples taken over not more
than a 30 day period, shall
not exceed a geometric mean of
200/lOOml nor shall more than
10% of the samples during any
30-day period, exceed 400/ml.
2-16
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of water quality with State standards. The water quality of Waller's
Creek is below State standards for the following parameters; dis-
solved oxygen, total dissolved solids, total phosphate, ammonia,
phenols and fecal coliforms. The water quality of Feehanville
Ditch probably approaches the same magnitude of degradation as
presently exists in Weller's Creek.
6. Groundwater Aquifers in the Service Area
The Silurian bedrocks of the study area are overlain by 45 to
100 feet of glacial material. The textural composition of material,
which is often interbedded, ranges from clay to clayed silt, and
usually contains varying amounts of sand, gravel and boulders.
Waterbearing sand layers are common to this glacial deposit.
Analysis of drilling data indicates the water tables of this area
vary from 20 to 25 feet in the summer to around 40 feet in the winter.
The shallow aquifers of this glacial drift are hydraulically
connected with the underlying Silurian rocks. Groundwater in the
Silurian and Ordovician rocks occurs in joints, fissures, solution
cavities and other openings. The water-yielding openings are
irregularly distributed both vertically and horizontally. Available
geohydrologic data indicate that the rocks contain numerous openings
which extend for considerable distances and are interconnected on
an areal basis.
2-17
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Large quantities of groundwater are withdrawn from wells in
shallow dolomite aquifers of Silurian and Ordovician age in northern
Illinois. The Niagaran and Alexandrian Series of Silurian age yield
moderate to large quantities of groundwatei .
Most water-yielding openings occur in the upper one-third of the
shallow dolomite aquifers. A good relationship exists between glacial
drift and the upper part of the shallow dolomite aquifers. Highest
yielding wells are found in areas where the glacial drift immediately
overlying the shallow dolomite aquifers is composed of sand and
gravel.
Probable ranges in yields of shallow dolomite wells can be
estimated from specific-capacity frequency graphs, aquifer thickness
and areal geology maps, and water-level data. On the basis of these
data, potential wells of the project area could yield up to 40 to 60
gpm (gallons per minute ).
Recharge of the upper glacial drift-Silurian aquifer appears
to occur from local precipitation, but the low permeability of the
overburden soils may be reason to suspect some horizontal movement
from the west.
The lower Cambrian Ordovician aquifer reportedly received water
from horizontal movement in recharge areas in North-Central Illinois and
Southern Wisconsin; and vertical leakage through the overlying Maquoketa
formation. In 1958 this leakage was estimated to be approximately 11
2-18
-------
percent of the total water pumped from deep sandstone wells in the
Chicago region. The vertical leakage through the Maquoketa shale
is generally due to the large differential head between the aquifers
(and locally may be facilitated by faultb in the rock).
According to Walton (Future Water Declines In Deep Sandstone
Wells in Chicago Region, 111. State Water Survey-Reprint Series
No. 36, 1964) the practical sustained yield of the deep aquifers
in the Chicago region is 60 MGD which is less than the actual pumpage.
It is anticipated that Lake Michigan water may be made available to
municipalities in the future to limit the pumpage rates to the practical
sustained yield in the project area.
Regionally, the shallow groundwater aquifer system reportedly has
a supply in excess of pumpage and any lowering of the groundwater elevations
is not anticipated except for seasonal fluctuations and local variations
due to pumpage.
The pumpage rate and the pumpage subdivided by use over the whole
basin from this aquifer has not been established, but available well
records indicate that the majority of wells in the shallow aquifer are
private domestic service with pumpout rates between 5 to 50 GPM.
Municipal and industrial pumpage appears to be from the deep aquifer
which estimated on population, may have amounted to approximately
20 to 25 MGD for 1970, in the project area. (Average .
2-19
-------
per capita consumption 115gpd) of which approximately 3 MGD (11%)
infiltrated from the shallow Silurian aquifer.
Regional groundwater quality and quantity data for Cook, DuPage,
Lake, Mclienry, Kane and Will counties are presented in Appendix E.
This material is available in Technical Report #8 - Regional Water
Supply Report, September 1974, by the Northeastern Illinois Planning
Commission.
In addition, Water Conservation measures are described In the
above mentioned NIPC Technical Report and are included in Appendix
F.
c. Water Quality Management
Section 208 of the 1972 Federal Water Pollution Control Amendments
Act of 1972 provides for areawide planning for waste treatment management
in large urban - industrial areas of the nation which have severe and
complex water quality problems. The northeastern Illinois counties of
which the service area is a part have been identified as having such
water quality problems. The Northeastern Illinois Planning Commission
is currently organizing a 208 planning effort with local governmental
units. With the support of local governments, the Governor of Illinois
may designate an areawide waste treatment management planning area
(208 area) and may designate the Northeastern Illinois Planning
Commission (NIPC) as the official "responsible planning agency" for
208 planning.
2-20
-------
At this writing, the following service area governmental units
have supported through resolution, the designation of the six-county
area snd N1PC as the 208 planning agency:
Arlington Heights
Mount Prospect
DesPlaines
Cook County
Buffalo Grove
MSDGC has prepared a proposal as to their participation within
the 208 planning process.
The Northeastern Illinois Planning Commission has also completed
a Regional Wastewater Plan (1971), which will be a major component
of the 208 study.
The Illinois Environmental Protection Agency has the responsibility
for Section 303 of the 1972 Amendments whereby water quality problems
are identified and overall pollution abatement strategies are
established for all major river basins in the state.
d. Flood hazards
The flood-prone areas in the O'Hare service area have been mapped
for the 100 year recurring flood event. These maps are available
in 7.5 minute series (topographic) from the Northeastern Illinois
Planning Commission. Channelization of Higgins Creek is part of the
Willow-Higgins Creek Watershed, plan illustrated in Figure 2-4. This
plan consists of locating storm reservoirs along Willow-Higgins Creek
and channelizing various sections to protect against the 100-year
flood. A summary of the O'Hare area flood control activities is found
2-21
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O
o
FIGURE 2-4
2-22
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In Appendix A.
6. Biology
Most of the study area has become urbanized, with the original
prairie vegetation and oak-hickory deciduous forest being replaced
by agricultural lands, yards, parks, and urban areas. Principal
remaining natural areas occur along the Des Plaines River and its
tributary streams, and in the Ned Brown Forest Preserve. A variety
of birds and small mammals inhabit the service area. Agricultural
and urban runoff have polluted streams and affected the original
compositi.on of stream plants and animals. No endangered or rare
species from State and Federal lists are known to be present in this
area.
7. Air Quality
In order to evaluate the existing air quality in the vicinity of
the proposed projects, air quality data was gathered from several sources.
These included the Illinois Environmental Protection Agency, the Cook
County Department of Environmental Control, the City of Chicago Depart-
ment of Environmental Control, and an "Airport Vicinity Air Pollution
Study" conducted by the Energy and Environemntal Systems Division of
Argonne National Laboratory.
2-23
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2. Particulate Matter
The greatest amount of data available is the result of particulate
matter sampling. Data from the Argonne study indicate that for
O
sampling stations west of O'Hare levels vary from 46 /ig/m in upwind
conditions to 66 /ig/m for downwind conditions. On the other hand,
levels at stations east of O'Hare vary from 112 jug/m^ in upwind
conditions, to 66 /ig/m-5 in downwind conditions. The increase in
particulate values when winds are from the west suggests that the
airport does make a measurable contribution to the particulate loading
downwind of the airport.
The primary national ambient air quality standard is an annual average
o o
no greater than 75 JJg/m and a 24-hour maximum no greater than 260/ig/m-1.
Samples taken on airport property show that 100% of the 24-hour values
were 240 yig/m3 or_ less while 100% of the 24-hour samples outside the
airport were 180 yag/m or less.
At a Cook County sampling station southeast of O'Hare (Franklin
Park) the annual mean concentration of particulate matter in 1974 was
74^ig/m3. At another station northwest of O'Hare (and downwind), the
annual mean concentration for 1974 was 67/ig/m^. While both of these
stations met the primary standard for particulate matter, they were
Q
in violation of the secondary standard of 60^ig/m->. Data from a
City of Chicago sampling station east of O'Hare (Taft High School)
2-24
-------
from January, 1966 to December, 1974 shows an average annual mean
concentration of 89 jug/m-*. Obviously, it is very difficult to draw
any conclusions from this data because of the variability of wind
direction and the effects of surrounding .urea emissions. It does
appear however, that samples taken close to airport sources generally
violate standards, but that the concentrations of particulate matter
decrease with increasing distance from the airport.
b. Nitrogen Oxides
Because there is even less data available on this pollutant, it
becomes even more difficult to note any significant trends. National
ambient air quality standards state that, as an annual average,
Q
photochemical oxidants should not exceed 160 jig/m nor should they
exceed 0.08 ppm as a one-hour maximum. While some samples taken during
the Argonne study recorded levels as high as 540 jug/m3 (or 0.262ppm),
the variability in samples was extensive with some readings as low as
2.4yug/m3. For example, samples taken along the northern perimeter
of the airport range from 220 jag/m to 540 yug/m . Along the eastern
o 3
perimeter of the airport values ranged from 52 /ig/m to 187 /ig/m .
Comparisons of samples on airport property and those outside O'Hare
show levels of 209 /ig/m for the former and 109/ig/m for the latter.
Results of samples taken by Cook County show an annual 1974 mean of
O n o
65 ^ig/m with a range from 32/ig/m-5 to 110 /ig/m . Similar samples
taken by the City of Chicago east of O'Hare (Taft High School)
2-25
-------
indicate a 1974 annual average of 0.036 ppm. The Argonne study concluded
that concentrations of NO and NOX were substantially higher in active
mobile source areas of the airport than in the surrounding neighborhood.
The highest N0x readings were obtained at both the gate areas and near
the ends of runways 14R and 14L. As with particulate matter, it can be
seen that monitoring over a long period of time results in annual averages
which are well within the standards. However, it is very common that
in certain areas, spot samples will result in readings which greatly
exceed the hourly standard.
c. Total Hydrocarbons
In the case of this pollutant it was found that the background levels
of total hydrocarbons (TCH) were so high that it was not possible, in the
case of the Argonne study, to determine the impact of aircraft emissions
on the air quality in the area. The maximum standard for a 3-hour period,
which is not to be exceeded more than once a year, is 160 ^ig/m-5 (or 0.24 ppm)
Sampling of the northern perimeter revealed THC levels from 1934 ^ig/m->
*} 1 "^
to 2330/ig/mJ with a range from 1700jug/nr to 1950/ig/mj along the eastern
perimeter. THC levels outside O'Hare in Elk Grove Village (west of Site #1)
o o
ranged from 1535 >ig/mj to 2100 /ig/m. The Argonne study noted that the high
background THC could be largely methane which is relatively stable in the
atmosphere while the contributions coming from aircraft may contain a
substantial fraction of reactive hydrocarbons so that these contributions
could be significant with regard to the production of photochemical smog.
2-26
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The Argonne study indicated that it was highly questionable whether
aircraft emissions would have a detectable effect at ground level
because of the interference with ground based emissions. Visual
observations of the exhaust plumes saw thon transported to ground level
at distances of about one to two miles from the runway end. The visibility
of the exhaust plumes near the surface within one or two miles of the
airport as well as their detectability at flight levels suggest that at
least one type of impact of particulate emissions is to increase the
atmospheric pall in the airport vicinity.
In general, it appears that air quality in the vicinity of the
project sites is severely degraded because of the proximity to O'Hare
airport. While comprehensive sampling indicates that the standards for
some pollutants are not violated, spot sampling would certainly indicate
a noticeable degradation of the air quality in the area.
2-27
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8. Land Use
Figure 2-5 indicates various land uses in the area of the proposed
interceptor. The Northern Illinois Planning Commission (NIPC) has
identified by 24 categories, the acreage of actual land use as of
1970. The NIPC "Landuse 70" elements by code number are:
1 - Residential - single family
2 - Residential - multi-family
3 - Residential - mobile homes
4 - Manufacturing - except wholesale
5 - Transportation, Communications, Utilities
6 - Railroad right-of-way
7 - Airports
8 - Streets
9 - Trade
10 - Services - private
11 - Services - institutional
12 - Military
13 - Cemeteries
14 - Entertainment assembly
15 - Public buildings
16 - Public and quasi-public open space
17 - Mining and excavations
18 - Vacant, Agriculture, Forest
19 - Vacant - under development
20 - Water - exclusing public open space
21 - Warehousing - storage structures
22 - Shopping centers - including parking
23 - Hotels, motels, transient lodging
24 - Parking - independent
The following table indicates the land uses of the quarter-sections
through which the interceptors are proposed:
2-28
-------
32
33
$£$$£
y.v_
-------
NIPC Category // Land Use Type Acreage
1 Residential-Single Family 1430.4 acres
2 Residential-Multi Family 82.8
3 Residential-Mobile Homes 11.8
4 Manufacturing-except wholesale 334.1
5 Transportation, Communications, 55.7
Utilities
6 Railroad right-of-way 21.2
8 Streets 606.6
9 Trade 123.5
10 Services-Private 6.9
11 Services-Institutional 103.9
16 Public & quasi-public 171.7
open space
18 Vacant-agriculture, forest 1218.9
1
-------
Air and water quality may be threatened by the trend in land
use changes which include more people, cars, and construction of homes,
offices, industrial plants and shopping centers. The availability of
vacant land is not the only criteria for future development. Several
open space agencies exist within the service area (for example local
Park Districts) which are authorized to acquire lands for park and
recreation purposes. These agencies contribute to the overall environ-
mental improvement by preserving lands for recreational and environmental
educational uses. The trend toward open space preservation should be
included in land use alternatives considered in the various plans
prepared by local agencies.
Comprehensive planning is the process by which a public planning
agency provides for orderly development of an area and promotes a
desirable environment. By this process, physical development is
coordinated in accordance with present and future needs.
Plans and programs usually include a land use plan, a thoroughfare
plan, a common facilities plan and public improvements program.
Administrative and regulative measures to control and guide physical
development according to the plans include a zoning ordinance, an
official map and subdivision regulations.
A land use plan shows the location and extent of lands designated
for various kinds of residential, institutional, commercial, industrial
and public purposes. Current land use planning within the service area
is being carried on by a variety of governmental units.
2-31
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The "Summary of Local Planning Documents in Illinois," prepared by
the State of Illinois Department of Transportation (1973), lists the
following plans:
Arlington Heights Comprehensive Village Plan (revised 1967)
Preliminary Planning Report 1968
DesPlaines Comprehensive Plan 1971, Zoning Ordinance
1971
Elk Grove Village Comprehensive Plan, 1967
Mount Prospect Comprehensive Plan, 1968
Rolling Meadows Subdivision Control Ordinance (amended 1964)
Wheeling General Development Plan, 1965
The Cook County Zoning Board of Appeals is currently preparing a
new zoning map and zoning ordinance. Additionally, the county has a
traffic safety study in progress.
9. Sensivite Areas
No properties included in or eligible for inclusion in the National
Register of Historic Places are in the area of the tunnel system. No
rare or endangered species, from either State of National lists, are
known to occur in this area. The major open space area is the Ned Brown
Forest Preserve. It is important both as a biological and recreational
resource. Tunnels will be constructed under parkland in Des Plaines and
Mount Prospect. About 1.4 acres of parkland would be affected by con-
struction of the dropshafts and access manholes.
10. Population Projections and Economic Forecasts
The projected population forecast of the Northeastern Illinois Planning
Commission (NIPC) is shown in graphical form in Figure 2-6, and in Table
2-2. The present population in the O'Hare Service Area is approximately
250,000. The projected population for the design year of 2000 is 300,000.
2-32
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POPULATION FORECAST
O'HARE FACILITY AREA
450
200
1970
1980
1990 2000
YEAR
2010
2020
2030
FIGURE 2-6
POPULATION FORECASTS
2-33
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Table 2-2. Population forecasts for the O'Hare Service Area.
(Source: Northeastern Illinois Planning Commission)
YEAR Forecast Population
1976 223,000
1980 261,000
1990 277,000
2000 300,000
Economic forecasts available are limited to projections of employment
by townships prepared by NIPC. The three townships principally in the
O'Hare Service Area are Elk Grove, Maine and Wheeling. The employment
forecasts for these townships are shown in Table 2-3.
Table 2-3. Employment forecasts for the O'Hare Service Area
(Source: Northeastern Illinois Planning Commission)
Township
Elk Grove
Maine
Wheeling
TOTAL
1970
37,257
52,767
24,916
114,940
1980
43,400
68,600
31,200
143,200
1990
46,300
74,300
34,300
154,900
2000
47,100
75,800
34,700
157,600
11. Other Programs in the Area
New federal legislation entitled the "Housing & Community
Development Act of 1974" provides the possibility of -funding for
community development activities. Within the service area, two
2-34
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communities, Arlington Heights and DesPlaines have populations greater
than 50,000 and thus are eligible for their own "entitlement" moneys.
Cook County would be eligible for funds as an "Urban County" under
tills art. Sewer construction is one eligible activity under the
program. Future growth capacity could be stimulated by this federal
program and ultimately serviced by the MSDGC.
2-35
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CHAPTER 3
CONVEYANCE SYSTEM ALTERNATIVES
A. Project Objectives
1. The elimination of combined sewer overflows into Weller's Creek
and Feehanville Ditch.
2. The conveyance of wastewater generated within the Upper Des Plaines
Drainage Basin to the proposed Water Reclamation Plant (WRP)
located in the service area.
3. The minimization of the environmental impacts of construction on the
extensively developed residential areas in the Upper Des Plaines
Drainage Basin.
B. Constraints
There were three principal constraints on the selection and design
of alternative systems:
1. The Weller's Creek and Feehanville Ditch Drainage Basins are
extensively developed, primarily in residential uses sensitive to
disruption.
2. The 29 outfalls in the study area will be, by December 1977, in
violation of the Illinois Environmental Protection Agency (IEPA)
water pollution regulations adopted by the Illinois Pollution Control
Board in July 1973 and approved by USEPA.
3. For the project to be economically feasible, routings between a
treatment plant and the overflow points should be as direct as
possible.
3-1
-------
L...J. \
-'UPPER DES PLAINES
DRAINAGE BASIN^
- ,--.-, ,,. ... ,- .. --»-
' i-j'.. ,'-.5 ; ^ (
"! """r-; l"-: l--, *
^aib^-^^?^-^^'11^*""*"****^.^ "^
LEGEND
M.S.D.G.C. COMBINED-SEWER SERVICE AREA I "ii,.
FIGURE 3-1
METROPOLITAN SANITARY DISTRICT OF
GREATER CHICAGO GENERAL SERVICE AREA
3-2
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C. Chronology of Plans and Studies
The Metropolitan Sanitary District of Greater Chicago is divided
into eight service basins. Of particular interest in this statement
is the Upper Des Plaines Drainage Basin,delineated in Figure 3-1.
Collection and treatment of sewage generated in the Upper Des Plaines
Basin has been the subject of many studies and reports. Based on a
report by Greeley and Hansen submitted in 1962, a tentative decision
was made to convey all sewage from the area to the West-Southwest
treatment works at Stickney. Following the Greeley and Hansen 1962
report, additional studies and investigations, carried out primarily
because of the trend toward higher standards for disposal of treated
effluent, have indicated the advisability of collecting and treating
the sewage from each drainage area separately. The policy of separa-
tion of drainage areas has been adopted by the MSDGC and four treatment
works are planned for the Northwest Area. The four systems have been
designated as O'Hare (Upper Des Plaines), Salt Creek, Hanover Park and
Poplar Creek.
A preliminary design concept for the O'Hare Water Reclamation Plant,
and an estimate of cost of both the intercepting sewers and the recla-
mation facilities was prepared in report form for the MSDGC by Brown and
Caldwell, Consulting Engineers, dated June 1968. Preliminary plans for
the intercepting sewers were prepared by De Leuw, Gather & Company,
Consulting Engineers, in accordance with an agreement between that firm
and the MSDGC.
3-3
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D. Alternatives
There are three basic alternatives to the wastewater management
problem within the Upper Des Plaines Drainage Basin. Given the need to
provide additional treatment capacity, and the laws governing the dis-
charge of combined sewage into surface waterways, there are: 1) Sewer
separation, 2) Conventional interceptors, and 3) Interception and
conveyance of combined sewage. Certain of these alternatives can be
combined; in addition, the basin alternatives themselves have
sub-alternatives within the context of their own plan.
1. Sewer Separation This alternative consists of the elimination of
the combined sewer system throughout the Villages of Arlington Heights
and Mount Prospect, and the City of Des Plaines.
Detailed engineering and cost analyses have not been made for the
the Upper Des Plaines Basin for this alternative; however, such analyses
were made for Palatine, Illinois, a neighboring community of similar
character. In the latter instance, two methods were investigated:
construction of a new sanitary sewer in every street within the
combined area and conversion of the existing combined sewer to a
storm sewer; or, construction of new storm sewers and conversion of
the existing facility to a sanitary sewer. In practice, there
would be some waste in either method, since the existing sewers are
generally larger than required by sanitary flows, and not large
enough to accommodate storm flows of the magnitude required to
eliminate flooding. Perhaps a more efficient solution may be
conversion of the larger existing facilities to storm sewers to
sanitary sewers.
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The alternative would involve construction within every block of
every street. Construction within any given block length would
probably require several weeks, excluding construction time for the
replacement of permanent pavement. Such a program could extend
over a period of several years, depending upon the magnitude of the
area the municipality chose to impact at one time.
2. Conventional Intercepting Sewer Two conventional systems were
examined:
a. A system of conduits which would intercept the existing MSDGC
intercepting sewers within the Upper Des Plaines Basin and
direct the sanitary flows to the proposed Water Reclamation
Plant. Two subalternatives were developed which differ only
in alignment. The least costly scheme would have a total
project cost of approximately $24.2 million (1972 dollars).
b. Conventional intercepting sewers, together with sewer
separation.
3. Collection and Conveyance of Combined Overflows This alternative
consists of collecting overflows from the existing outfalls, and
conveying combined sewage to the proposed Water Reclamation Plant
for treatment prior to discharge to the waterway. The system would
consist of large diameter rock tunnels, together with necessary
appurtenant structures to connect the existing combined outfalls and
redirect the combined overflows to the rock tunnel system.
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4. A no action alternative was also considered for purpose of evaluation.
This alternative consists of simply doing nothing with regard to
combined sewer overflows into Weller's Creek and Feehanville Ditch
or diversion of flows to the proposed O'Hare Water Reclamation
Plant. Impacts on water quality of Weller's Creek as a result of no
action are discussed in Chapters 2 and 5. All sanitary sewage
generated within the basin would continue to flow thru interceptors
to North Side Sewage Treatment Works.
E. Comparative Analysis of Alternatives
To evaluate the various options available for wastewater management
within the Upper Des Plaines Basin, six alternatives were assessed in
relation to project objectives (See Table 3-1).
Table 3-1 Comparison of Alternatives and Project Objectives
Project Objective
Alternative No.
Eliminate Conveyance Minimize Environ-
Combined to mental Impacts
Overflows Plant of Construction
1. Sewer Separation
2A. Conventional
yes
no
no
yes
no
yes
Interceptors
2B. Separation with
3A. Collection and
Conveyance of
Combined Overflows
3B. Collection, Conveyance
and Storage of Combined
Overflows
4. No Action
* Partial
yes
*yes
yes
no
yes
yes
yes
no
no
yes
yes
yes
3-6
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Two alternativesseparation with interceptors (Alt. 2B) and collection,
conveyance and storage (Alt. 3B) would meet the first two project
objectives. In addition, the collection/conveyance alternative (Alt. 3A)
would meet the second objective and greatly reduce overflows. This
alternative partially meets objective one and would result in a 72 percent
reduction in total volume of spills, a 93 percent reduction in number of
spills and a reduction in the number of average yearly spills from
approximately 80 to six.
In the selection of alternatives for further screening, only those
which were at least in part responsive to project objectives were
carried forward.
F. Final Systems Screening
Three alternatives were selected for more detailed analysis. These
were:
* Separation with interceptors.
* Collection and conveyance of combined overflows.
* Collection, conveyance and storage of combined overflows. The
proposed Water Reclamation Plant is designed to handle peak dry
weather flows only and not the peak wet weather flows from combined
sewer areas. MSDGC plants are normally operated at full capacity
before and after storms to minimize the overflows of untreated flow.
It is not cost-effective or feasible to increase the plant peaking
capacity to match the rate of storm runoff, which for the 11.4
square mile combined sewer area may reach over 30 times the dry
weather flow for the entire 58.2 square mile basin.
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1. Separation with Interceptors Alternative
Of the 7,322 acres of combined area in the Upper Des Plaines
Basin, 1,370 have separate local sewer systems, which are recombined
at the dowstream end with the combined system, leaving 5,952 acres
which would require new separated sewer systems. A detailed
analysis of Palatine, Illinois indicates that the cost of a new
separate sanitary sewer system would be approximately $12,700 per
acre. For the O'Hare Service Area this results in an estimated
separation cost of $75.6 million. In addition, if separation were
accomplished, conventional interceptors would still need to be
constructed at an estimated cost of $23.2 million for a total system
cost of $98.8 million.
While this alternative would achieve the objective of elimination
of combined sewer overflows, it would have other severe environmental
implications. The amount of surface disturbance necessary would be
extensive. Even with considerable construction safeguards, there
would still be a significant quantity of erosion and runoff due to
the construction and separation of the sewer systems. In addition,
the quantity of material resources necessary for this alternative
would be significant.
2. Collection, Conveyance and Storage of Combined Overflows Alternative
A detailed engineering analysis was made of tunnel and reservoir
alternatives. A report titled "Preliminary Plans for O'Hare Collection
Facility," dated November 1972, presents a summary of this analysis
and tunnel and reservoir concept plans. The estimate for the preferred
3-8
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tunnel and reservoir scheme selected for the total basin is $88.5
million. This figure is established from Chapter XI, of the De Leuw,
Gather report by adding the estimated land cost to the estimated
construction cost (including 20 percent for contingencies) and
deducting the $18.8 million estimated cost of the Palatine area
projects. (Palatine area projects are no longer planned to be
interconnected to the O'Hare tunnel conveyance system).
It has been estimated that the average yearly volume of combined
sewage intercepted by the tunnels and reservoir would be 6670 acre-feet.
This is equivalent to a runoff of approximately eleven inches over
entire combined sewer area in the basin. This 6670 acre-feet is
equivalent to a yearly volume of 2.17 billion gallons or 5.95 MGD
average additional flow to the plant.
The treatment cost for the additional combined over-flows
intercepted by the tunnel and reservoir concept projects may be
estimated as follows:
Yearly Cost Total Cost
Additional flow due $155/MG times
to interception of 365 days/year
combined sewage times 5.95 mgd=
flows 5.95 MGD $336,621/year
times (Present
Worth Factor of
6%/50 years
15.762) = $5,305,820
Therefore a cost comparison for separation versus a tunnel and
reservoir plan by only $5.0 million, the following factors should be
considered:
a. The maintenance and operation cost estimated at $144/MGD is
3-9
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very conservative for combined sewage treatment. It is based
on the MSDGC surcharge ordinance which relates to the treatment
of sanitary sewage and industrial wastes.
b. The assumption of a 50-year maintenance and operation cost
is cons erva t ive.
c. The cost of inconvenience to the public by excavation in
every street in the combined sewered area, as would be
required in the sewer separation alternative, is not reflected
in the cost comparison.
d. The cost of required replumbing for buildings in the combined
sewered area is not included in the $12,700 per acre cost used
for sewer separation.
e. The monetary value of pollution reduction by the treatment of
polluted urban runoff is not reflected in the cost comparison.
3. Collection and Conveyance of Combined Overflows Alternative
The MSDGC has opted not to construct the reservoir portion of the
tunnel and reservoir plan at this time. Such a decision results in
a system of rock tunnels identical in structure to those of the tunnel
and reservoir plan. This option is referred to as the Rock Tunnel
Alternative. All flow characteristics, connections, locations and
sizes would remain the same as those under the tunnel and reservoir
plan, but the storage volume would be reduced to that of the volume
of the tunnels.
The completed Rock Tunnel Alternative system will provide approxi-
mately 200 acre-feet of storage for combined sewage capture. This
3-10
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is sufficient volume to contain approximately 1/3 inch of runoff
from the entire 7322 - acre combined sewer area. Using a combined
runoff factor of 45 percent, this is equivalent to the runoff from
a 3/4 inch rainfall over the Upper Des Plaines combined sewer area.
Computer model studies indicate that approximately 72 percent
of the volume of all combined sewer discharges to Weller's Creek and
Feehanville Ditch would no longer occur on completion of the tunnel
system. This would reduce the biochemical oxygen demand (BOD) and
suspended solids discharged by approximately 92 percent and 93
percent, respectively. Cost of a system of collection and conveyance
rock tunnels including all appurtenant structures to provide an
operating facility is estimated to be $36.5 million (1972 present
worth).
The Rock Tunnel Alternative is described in greater detail in
Chapter 4 and assessed in Chapter 5 for comparative purposes with the
no action alternative.
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CHAPTER 4
DESCRIPTION OF THE PROPOSED ACTION
The proposed action consists of a network of tunnels and shafts ranging
in diameter from 5 to 20 feet. A majority of the tunnels (6.63 miles) would
be located approximately 160 feet below the ground surface in rock. The
remaining 3.22 miles of earth tunnel would be at depths approximately 40 feet
below the surface. See Figure 4-1.
This network is designed to collect all combined sewer overflows within
the project area and direct them together with sanitary flows, to the
south end of the tunnel system. A description of each contract of the proposed
project is given in Chapter 1. All earth tunnels will be lined with 12 inches
of concrete and all rock tunnels with 10 inches of concrete.
A. Main Tunnel
The main rock tunnel would be 20 feet in diameter and run north along
Elmhurst Road from a main shaft located approximately 400 feet southwest of
the intersection of Elmhurst Road and Northwest Tollway to Drop Shaft 4. From
Drop Shaft 4 the main tunnel would proceed northwest along Weller's Creek
to Drop Shaft 1 located approximately 400 feet north of the intersection of
Central Road and Weller's Creek.
B. Branch Tunnels
The east branch tunnel would be 16 feet in diameter. It would begin
at a junction with the main rock tunnel at the intersection of Elmhurst Road
and Lonnquist Boulevard, and proceed east in Lonnquist Boulevard to Drop
Shaft 6 at Williams Street, then turn north and follow Williams Street to
Drop Shaft 8 located approximately 200 feet northeast of the intersection
4-1
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/ 1
LEGEND
ROCK TUNNEL
(APPROXIMATELY 1 SO FEET BELOW SURFACE)
Illlllllllll EARTH TUNNEL
(APPROXIMATELY 60 FEET BELOW SURFACE)
A DROP SHAFT
SCALE IN MILES
O 1/4 1/2
1 1/7
FIGURE 4-1
ROCK TUNNEL ALTERNATIVE
4-2
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of Isabella Street and Rand Road. A nine-foot rock tunnel would junction
with the east branch at Lonnquist Boulevard and Williams Street, and proceed
east along Weller's Creek to Crop Shaft 5 located at Weller's Creek and
Mt. Prospect Road.
A five-foot earth tunnel, to be lined with concrete, would begin at
Drop Shaft 5 and proceed north on Mr. Prospect Road to Princeton Street,
then east in Princeton to Wolf Road and north in Wolf Road to intersection
of Rand Road and Wolf Road.
Beginning at Drop Shaft 7 a five-foot concrete-lined earth tunnel
would extend west under Oakton Street approximately 2.08 miles to the
intersection of Oakton Street and Wildwood Road.
C. Sequencing of Tunnel Construction
It is anticipated that construction of the 4 tunnel contracts will
commence on approximately the same date. The connection and laterals
contract, U.D. 20A (Contract 73-318-2S) is expected to be awarded approximately
one year later.
Tunnels are generally excavated in an upgrade direction since this
facilitates dewatering and muck removal. However, for the rock tunnel
project it is anticipated that spoil removal, specified shaft location and
the magnitude of the projects will be a more important consideration.
1. U.D. 20 (Contract 73-317-2S)
Tunnelling will commence at the main shaft at the southwest corner of
the Northwest Tollway and Elmhurst Road and proceed northerly and westerly
to the site of Drop Shaft No. 1 located at Central Road east of Busse Road
4-3
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2. U.D. 21 (Contract 73-320-2S)
Tunnelling for the 16 foot diameter tunnel will commence at the site
of Drop Shaft 8 at Rank Road and Isabella Street and proceed, reverse grade,
southerly and westerly to a junction with U.D. 20 at Elmhurst Road and
Lonnquist Boulevard.
Tunnelling for the 9 foot diameter tunnel will commence at the location
of Drop Shaft No. 5 at Mt. Prospect Road and Lonnquist Boulevard extended
and extend westerly to the junction with the 16' diameter tunnel at Lonnquist
Boulevard and Williams Street.
3. U.D. 20B (Contract 73-319-2S)
Tunnelling will commence at Lonnquist Boulevard (extended) and Mt.
Prospect Road and proceed northerly and easterly to Wolf and Rand Roads.
4. U.D. 20C (Contract 69-307-2S)
Tunnelling will commence at the location of Drop Shaft 7 at Elmhurst
Road and Oakton Street and proceed westerly to Oakton Street and Wildwood
Road.
The tunnel water detention basin required for U.D. 20 will be located
immediately west of the main shaft. Water infiltrating into the tunnels will
drain by gravity to the low point in the tunnel system at the location of the
junction with the 7-foot diameter plant influent tunnel. From this point it
will be pumped out through the main shaft to the detention basin which will
be pumped or drained by gravity to Higgins Creek immediately west of the
site of the Main shaft.
4-4
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Excavated material will be removed from the tunnels at main shaft
sites. Transportation in the tunnels will be by muck cars traveling on
rail tracks laid in the tunnels. The material will be removed from the
tunnels by a crane or elevator hoisting system. It will then be deposited
near the shaft at a temporary storage location or hauled immediately
from the site to its ultimate user. Market conditions and available storage
space will dictate the amount and time of storage. The MSDGC owns
approximately 112.5 acres adjacent to the main shaft, part of which will
be made available for spoil storage.
The material excavated will be composed of spalled or laterally split
rock of small dimensions with a large percentage of fines. As this
material does not have a. gradation conforming to accepted specifications
for concrete aggregate or roadway base material, it is not generally
acceptable for these purposes. However it has been used in private
developments for such things as stone base for parking lots. The primary
use of this material is expected to be as land fill.
D. Main Shaft and Drop Shafts
The main shaft is the location for lowering and removing the mining
machines. Men, equipment and material will enter and exit from the tunnel
system from this shaft during construction. Dewatering during construction
will take place at this location.
After construction, the main shaft will serve as part of the exit
structure from the tunnel system should a reservoir eventually be constructed
at its terminus. The main shaft is in fact located on the proposed site
for a main reservoir which was proposed by DeLeuw, Gather and Company in
the preliminary plans. After construction the main shaft, having a finished
4-5
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internal diameter of 16 feet, will be capable of being used for lowering a
maintenance vehicle into the tunnel system.
A drop pipe will be provided at the Main Shaft to extend service to
the portion of the service basin area south of the Tollway.
Drop Shafts
Shaft Number Location
1 Approximately 400 feet north of the inter-
section of Central Road and Weller's Creek.
2 At the intersection of Weller's Creek and
Lincoln Street.
3 Within the park along Weller's Creek
approximately opposite Wa-Pella Avenue.
4 At the intersection of Weller's Creek
and Elmhurst Road.
5 At the intersection of Weller's Creek
and Mt. Prospect Road.
6 At the intersection of Williams Street
and Lonnquist Boulevard.
7 At the intersection of Elmhurst Road
and Oakton Street.
8 Approximately 200 feet northeast of the
intersection of Isabella Street and
Rand Road.
The shafts would require excavation approximately 160 feet deep into
the overburden soils and rock. These excavations would require temporary
sheeting and bracing to support the adjacent earth until the permanent
structures are constructed and backfill work is completed. Blasting would
be required for excavation of the rock portions. This blasting would
continue for approximately one month at each shaft and be limited to one
4-6
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blast every two or three days. During the construction of the shafts
the work areas would be fenced and secured in accordance with MSDGC
standard practices. The shafts would vary in size from five to nine
feet in Internal diameter. Construction would proceed from the surface
downward to the tunnel level.
A sectional view of the Type D-4 drop shaft to be used in the Upper
Des Plaines Tunnel Conveyance System is shown in Figure 4-2. It is noted
that the air insufflated into the water on its way down the shaft in
the downcomer is released in the separation chamber. This air rises
in the vent shaft and becomes reinsufflated into the incoming sewage
at the top of the downcomer. There is, therefore, no net movement
of air out of the drop shafts. During model studies the vent shaft
openings to the atmosphere at the top of the structures were sealed during
some of the experiments, thereby precluding the possibility of air movement
out of the shafts. This did not affect operation of the drop shaft.
While the aspect of aerosol release at the top of the vent shaft or
downcomer was not specifically studied in the model study program, MSDGC
observed that this phenomenon did not appear to be occurring. In the
event that the prototype drop shaft does operate differently from the
models and the phenomenon of air movement out of the shafts does occur
the openings to the surface of the ground could be sealed without hydraulically
affecting the structures.
Sluice gates will be placed in collection structures at the location
of all major sources of storm water inflow into the tunnel system. These
gates will be provided with an alternate power supply or other means to
insure their operation when required. The gate status will be continuously
4-7
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DROPSHAFT D-4 TYPE
UPPER DES PLAINES TUNNEL PLAN
GROUND LEVEL
RECIRCULATIN6 AIR
SUMP-
tAIR SEPARATION CHAMBER
x-^l * \
*°o I U[ 1
'/X?'^>*^re&%<:\ - ' I . ° * '
' Ci-Oo o Q o..o;fij=y»Q-^«;y-Tr^"*>vr-'>;^"-;
c ° _O, ;.uo o oo-i,'ct^~tWoo^B-SL -«r a_,*
»*OC7Q <^0°* oOos^^yg^gZ -S±:
O^. ^ r-K'*-
-------
monitored (visually and be computer) at the proposed O'Hare Water
Reclamation Plant. In the proposed tunnel conveyance system the gates
will be closed as necessary during major storm events to prevent filling
of the rock level tunnel system above a level higher than the crown at
the upstream ends of these tunnels. This will prevent rapid filling of
the drop shafts which might result in hydraulic surges. In addition by
keeping the rock level tunnels from being surcharged potential backup of
local sewer systems will be prevented.
E. Access Manholes
Access manholes would be constructed at approximately 2,000-foot
spacing along the work tunnel alignments. Under current MSDGC practices
manholes are placed at approximately 600-foot spacing along tunnel
constructed through earth. These manholes would be constructed from the
surface downward in a manner similar to the drop shafts; however, they
would require a much smaller excavation. Some blasting would also be
required in the excavation of some of these elements. Access manholes
would be located within or adjacent to the parkway or shoulder area
of public roadways. The construction period for an access manhole is
approximately three months.
F. Relationship of Proposed Action to Existing Facilities and Other Projects.
The physical relationships between the existing combined sewer systems
and the proposed conveyance system are exhibited in the preliminary plans
for the project. (Preliminary Plans for O'Hare Collection Facility, November
1972, De Leuw, Gather & Company)
4-9
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These preliminary plans illustrate that under the ultimate plan
(reservoir included) sufficient storage capacity will be available with
the facility to permit plugging the smaller combined sewer overflows.
The larger interceptor outfalls are maintained to serve as safety valves
for the system. Under the proposed plan, all existing overflows will be
maintained due to limited storage capacity. The volume of the proposed
conveyance tunnels is approximately 220 acre-feet.
The existing combined sewer systems have been estimated to be slightly
less than capable of handling a storm of 5-year return frequency. This
evaluation is a generalization, however, since some subsystems very likely
have a capacity of even less than this. The proposed tunnel facilities were
planned to provide a flow-through capacity sufficient to handle the
"storm of record" without creating surcharging in the existing combined
sewer system. The existing systems do not have the capacity to handle
the storm of record volume, and accordingly provisions are made in the
design of the proposed facility for future relief of the existing system
by the local municipalities.
The total mass discharge from all combined sewer outfalls within
the project area for the 21 years used in the study analysis is 140,000
acre-feet. This arithmetically averages to 1,867 acre-feet per year being
discharged to the waterways after the facility is in operation. These
remaining overflows will continue to occur at the existing outfalls.
Tunnel maintenance, when required, must be done by entering the tunnels
and performing the work in accordance with procedures common within the
industry. No techniques or equipment not presently available are expected
to be required. In the event the tunnels must be entered, all inflow and
4-10
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control gates must be closed, and dry weather flow diverted to the North
side plant for processing. Gates are provided at all inflow points to
the proposed tunnel system.
The design of the tunnel system of the Upper Des Plaines Tunnel Plan
does not depend on or interact with the design of small, local storm
water retention basins, whether existing or to be constructed by the
Villages of Mount Prospect and Arlington Heights. The Upper Des Plaines
Tunnel and Reservoir Plan contemplates two reservoirs, the Main or Upper
Des Plaines Storage Reservoir, possibly to be located on a site at the
southwest corner of the Northwest Tollway and Elmhurst Road adjacent to
the Main Shaft, and the Mount Prospect Detention Basin to be constructed
adjacent to Drop Shaft No. 1 at Central Road east of Busse Road.
It is noted that the Main Reservoir and Mount Prospect Detention
Reservoir would fill only irregularly. Reference to the DeLeuw, Gather
and Company Report, (Figure XI-3 on Page X-8), indicates that in the 21
years of records studied, the computer simulation study indicated that
the detention basin would detain more than 100 acre-feet only 8 times, and
more than 300 acre-feet four times. Further, the reservoir remains completely
dry except on 24 occasions in the 21 years of record, or approximately
once a year. The volume of the detention basin as proposed in the DeLeuw,
Gather and Company Report is 850 acre-feet. Under the simulated condition,
when the Mount Prospect Basin filled to the greatest extent (810 acre-feet)
during the July, 1957 storm, the basin was empty 19 hours after it began
to be filled. (This is seen by examination of Table XI-2 on Page XI-5
of the DeLeuw, Gather Report.)
4-11
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The Main Reservoir, on the other hand, is a retention basin. As the
dewatering rate (24 MGD) is very small relative to the inflow rate during
storms, its size is essentially equal to the volume of runoff in the
combined sewer area. Therefore the size of the Main Reservoir is almost
totally independent of the rate of runoff or presence of local retention
basins in the combined sewer area.
The MSDGC is in the process of entering into an agreement with Mount
Prospect and Arlington Heights for the construction of a 130 acre-feet
storm water retention reservoir on a portion of the site of the proposed
Mount Prospect Reservoir. This reservoir could be a shallow gravity
type, discharging storm water at a reduced rate to Weller's Creek. The
construction of this storm water reservoir would be made possible by sewer
separation within the tributary area, to be performed by the Villages of
Mount Prospect and Arlington Heights.
If the MSDGC proceeds with construction of the Combined Sewer Detention
Reservoir at the Mount Prospect site at a later date, the separate storm
water reservoir could be abandoned and its volume used for the larger
combined wastewater reservoir. However, based on feasibility studies it
is possible that it may prove feasible to have two reservoirs on the same
site, a storm water reservoir and a combined wastewater detention basin,
thereby not recombining the storm water but continuing to discharge it to
Weller's Creek without treatment.
At the present time the feasible alternate has not been determined
but this will be established prior to constructing the storm water reservoir.
At this time the MSDGC does not plan to treat storm water except where
this is the most economical manner of reducing combined wastewater-caused
pollution of waterways.
4-12
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The only sewer tunnel and/or combined waste water reservoir projects
which may be implemented in the next 20 years in the Upper Des Plaines
Service Basin, are the O'Hare (Main) Reservoir, the Mount Prospect Detention
Basin and the Upper Des Plaines Intercepting Sewer 22 (Contract 73-314-2S).
This intercepting sewer will be an earth tunnel which will serve a separate
sanitary sewer service area and will relieve the existing Upper Des Plaines
14A and 14B interceptors in Wolf Road. The service area, size, location
and other information related to this intercepting sewer are shown on
Figure 4.3.
No determination of the desirability of constructing the combined
waste water reservoir(s) or additional sewer line has been made in this
EIS. Possible future connections are reported for the purpose of identifying
some options that are available through implementation of the proposed
tunnel conveyance system.
The selection of the tunnel conveyance system as the proposed sewer
intercepting system for the O'Hare Service Area does not predetermine
the site of the Water Reclamation Plant.
The location of the dropshafts, earth and rock tunnels are a function
of the existing sewers (especially those serving the combined sewer area),
hydraulic design parameters, and ease of construction and operation and
maintenance. Nine possible sites are considered in the siting of the
proposed Water Reclamation Plant (See the Draft EIS on the O'Hare WRP,
Chapter 3). At each site a 7-foot diameter influent sewer would be needed
to dewater the main 20-foot diameter rock tunnel. Thus, constructing the
recommended tunnel conveyance system leaves open the site selection process
for the Water Reclamation Plant.
4-13
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AREA SERVED 15.1 Sq. Miles
Design Population 122,616
ARLINGTON HEIGHTS
UPPER DES PLAINES 22
CONTRACT 73-314-2S
19,000 Ft. of 7'-6" Dia.
$6,750,000.
PROPOSED U.D. 21
TO O'HARE W.R.P.
EXISTING M.S.D.
SEWERS TO
NORTH SIDE W.R.P.
THE METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
ENGINEERING DEPARTMENT
FIGURE 4-3
4-14
MAY, 1973
-------
CHAPTER 5
ENVIRONMENTAL EFFECTS OF THE
PROPOSED ACTION
Four key components have been identified for the proposed action.
They are:
1) The tunnels
2) Eight drop shafts and one main shaft
3) Seventy access manholes
4) Nine monitoring wells
The proposed plan is thus composed of separate component parts, each of
which may produce a given impact or degree of impact depending upon its
location and size. In addition, the tunnel conveyance system would have
both beneficial and adverse impacts on the area as a whole. These two levels
of impacts combine to produce the overall impact that would be associated
with the proposed tunnel conveyance system.
A matrix summary of potential impacts at the end of the chapter indicates
the range and types of impacts involved in the proposed action.
A. Bedrock Geology
A large portion of the Rock Tunnel Alternative is located in the bedrock
strata. The general geologic sequence to be expected along this tunnel
alignment is illustrated in Figures 5-1 and 5-2. The geology as shown in
these figures is greatly generalized and the location, number, attitude and
condition of faults are totally interpretive and not verified by field
observations. However, the formations involved with the Rock Tunnel
Alternative are stable and the boring of the tunnel would not cause any
5-1
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X '
LEGEND
Sr RACINE
_U_
D
Sjr ROMEO
Sm MARKGRAF
Sk KANKAKEE
Ob BRAINARD SHALE
Faults
Formation Contact
NOTE I. ELEVATIONS IN FEET AND
BASED ON C.C.D (CHICAGO
CITY DATUM )
2 FAULTS REPORTED BY VIBROSEI^
SURVEY. HARZA ENGR. CO.
GEOLOGY AT TUNNEL ROOF
5-2
FIGURE 5-1
-------
NOTE I. ELEVATIONS IN FEET AND
BASED ON C.C.D (CHICAGO
CITY DATUM )
2 FAULTS REPORTED BY VIBROSEIS
SURVEY. HARZA ENGR. CO.
FIGURE 5-2
GEOLOGY OF TUNNEL INVERT
5-3
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slipping or instabilities.
Due to numerous vertical joints and high permeability of formations,
groundwater would seep into the tunnel during construction. Because the
tunnel would be fully grouted and lined, infiltration would be reduced to a
minimum after construction.
The linings for all rock tunnels will be 10-inch plain concrete with a
minimum 28 day compressive strength of 4,000 psi. This concrete is the
MSDGC standard for dense, watertight, durable concrete in contact with sewage.
Linings for earth tunnels will be 12-inch thick concrete identical to that
above, or precast concrete pipe depending on the Contractor's selection of
method of construction.
In the case of the proposed rock tunnels, the lining serves the principal
function of protecting mudstone partings, present in some of the rock members,
from continuous contact with the flowing sewage. See Figure 5-3.
The lining, once in place, serves to further reduce potential infiltration
and exfiltration by providing a continuous, virtually impervious barrier
between the tunnel opening and surrounding rock. For this reason, it is
believed that infiltration can be reduced below that accomplished with unlined
tunnels.
!
In addition to the concrete lining, the adjacent rock formations will
be grouted where necessary. This grouting is intended to seal openings in
the rock through which water may migrate either into or out of the tunnel
system. There is a practical limit with respect to opening size, with which
cement grouting may be effectively employed. Results of a previous grouting
program of a recently constructed facility indicate that openings with
infiltration rates less than 1/8 gpm are practically ungroutable, using cement
5-4
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ROCK TUNNELS
Surface
EARTH TUNNELS
-Surface
+6O
+52,
5O
OVERBURDEN:
ESTIMATED PREDOMINANTLY
PIEZOMETRIC
HEAD UNDER CLAYS AND SILTS
MAXIMUM
SURCHARGED
CONDITIONS
RANGE OF PREVAILING
GROUND WATER LEVELS
AT TIME OF SUB-SURFACE
INVESTIGATION
CONC. LINING
50
PROPOSED 5
TUNNELS EARTH
GENERALIZED STRATIGRAPHIC SECTIONS
FIGURE 5-3 5-5
75
100
E-i
W
w
125
150
175
200
-------
grout, with cost effective results. For this tunnel conveyance system lining
and grouting are intended to augment each other.
During the construction period, however, such inflow may temporarily
result in a lowered water table in the overlying glacial drift aquifer and
dewatering pumpage may contribute to short-term water quality degradation
(mainly turbidity) in Higgins Creek.
The proposed system would not be affected by the intensity of future
earthquakes predicted to occur in this area.
Approximately 350,000 cubic yards of dolomite would be removed during
a 2 to 3 1/2 year construction period estimated for various tunnel segments.
These dolomites and the overlying glacial material represent a natural
resource which should be utilized in a productive manner.
It is anticipated that the restricted usability of the tunnel spoil
material will reduce its value to an extent where double handling is unwarranted.
Therefore it is not expected that a high percentage of the material will be
stored near the main shaft sites. However in the event of storage of the
material it can be expected that it will have a lower permeability than the
unpaved ground surface thereby increasing storm runoff. The minor increase
in runoff and its short term nature minimize the significance of this negative
impact. The rate of removal w.ill be such that it is not expected to have any
significant environmental or economic impact.
B. Soils and Surficial Geology
The proposed project will have no significant effect on the weathered
surface soils of the project area, as the construction of the eight drop
shafts and one main shaft represents the largest modification. There may be
some soil compaction resulting from the operation of construction equipment
5-6
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in the vicinity of the drop shafts, manholes, and main shaft.
The earth tunnel portions of the rock tunnel plan would require removal
of approximately 8,000 cubic yards of subsoil. The composition of this
subsoil ranges from clayey silts to silty clays, with occasional sand lenses
and some gravel.
The 12-inch concrete lining in the earth tunnel portion will protect
the shallow aquifers present throughout these morainal deposits. Construction
techniques are designed to prevent collapse of the earth tunnel and subsequent
earth settling. These construction techniques have been utilized in the past
and have proven successful.
C. Hydrology
1. Surface Water
Implemention of the proposed plan would result in the improvement of the
water quality of Weller's Creek and Feehanville Ditch, as combined sewer
overflows to these streams would be reduced. The 29 area outfalls are
indicated on Figure 5-4. With the proposed tunnel system in operation,
combined overflows to these streams would be reduced from 80 occurrences per
year to fewer than six. This would respond to the IEPA Water Pollution
Regulations requiring provision for treatment of all combined sewer overflows
by December 31, 1977.
A dewatering program will be necessary during the construction of the
rock tunnel, as a flow up to 600 gallons per minute could be produced. This
water will be discharged into Higgins Creek after the water passes through
a settling basin of sufficient size to permit a one-half hour detention period.
The settling basin will be located near the main shaft. However, this water
may increase the turbidity of Higgins Creek in the1 short term as the water
5-7
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LEGEND
A EXISTING COMBINED SEWER OVERFLOWS
INUNDATED FLOOD AREAS OF JULY 1957
FIGURE 5-4
COMBINED SEWER OVERFLOW POINTS
5-8
-------
will not be retained fpr a sufficient period to eliminate all of the fine
limestone particles. A discussion of the impacts of the effluent from the
Water Reclamation Plant is discussed in the EIS on the Water Reclamation plant.
2. Aquifers
The proposed modifications should have little effect upon the groundwater
of the glacial material and those shallow aquifers in the Silurian dolomites,
as all tunnels will be lined to prevent infiltration and exfiltration.
However, during construction of the rock tunnels, there will be some loss of
water in the Silurian aquifers due to the necessity of dewatering. There
should be little water loss during the construction of the earth tunnels.
The MSDGC and its consultants have considered the general subject of
interference with private and municipal wells by construction activities or
by the completed Upper Des Plaines Tunnel Conveyance System.
The areas of study fall into two general categories effects during
construction activities and effects after completion of construction. The
subjects considered relating to construction operations are as follows:
a. Clouding or contamination of wells by tunnel .or shaft construction
operations;
b. Lowering of the water table during construction operations;
c. Clouding or contamination of wells by grouting operations; and
d. Reduction in well yields due to grouting operations.
The subjects considered relating to post-construction operation of the
completed facility are as follows:
a. Protection of the aquifers from contamination by sewage in tunnels;
b. Effect of completed facility on water table; and
c. Aquifer monitoring well operations, location, and standards.
5-9
-------
Following is a discussion of the potential impacts listed above.
There are a number of private wells in the vicinity of the 20-foot and
16-foot rock tunnels (Contracts 73-317-2S and 73-320-2S) that may be
influenced by the construction of these tunnels. The effect on these wells
is anticipated to be limited to some clouding during grouting operations.
These wells are thought to draw most of their water from the soil-rock
contact area. A monitoring well has already been located in the vicinity
of all known well areas, particularly near areas where complaints of cloudy
water were received during the subsurface exploratory program. These wells
will receive constant monitoring during construction. Should clouding
caused by the grouting operations occur, pump-out of the monitoring wells
may be sufficient to prevent the further migration of grout particles. If
these procedures fail to prevent cloudiness, fresh potable water may be
supplied for the short time required to complete the grouting and for the
water to return to its original state. Since the grouting is intended to
extend one tunnel diameter beyond the tunnel walls, no long-term effects on
the wells are expected.
The potential groundwater drawdown within the glacial till-Silurian
aquifer is extremely difficult to predict. The ability of water to migrate
from the soil-rock into the tunnel±sa function of the number of joints and
bedding planes intersected by the tunneL. No data is available which will
allow precise arithmethical determination of joints, bedding planes and
opening sizes which may be encountered. Several factors are known however,
if only in a general way, which enable a review of the existing soil-rock
conditions and an evaluation of how these conditions may impact groundwater
loss into the proposed conveyance system. The known factors are the results
5-10
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of soil and rock boring programs performed for the project, a review of
conditions that prevailed on a similar project before and after grouting.
The glacial till throughout the project area is predominantly fine
grained soils with an estimated coefficient of permeability of 10~" to
10 cm/sec. These soils do not readily release water and consequently will
not cause significant inflows into the tunnel which will be detrimental to
construction or water levels in the soild. Isolated sand and gravel pockets
exist within the glacial till which are discontinuous and not connected to
the surface. These pockets will hold limited amounts of water which, if
encountered by construction, will release their contained water. The quality
of such water appears to be extremely limited and is not known to be used
as a potable water supply. These wafers will be replaced» in time, after
completion of construction, by natural recharge.
The Silurian system is described in depth in Volume I, Bedrock Geologic
investigation of the Geotechnical Report on Upper Des Plaines Tunnel and
Reservoir Plan, Contracts 73-317-2S and 73-320-2S, dated July 1974. This
report describes the rock systems to be encountered! and postulates the
conditions expected to be encountered during construction. Since the water
bearing features within the rock consist of openings, primarily in form of
cracks and joints, location of the inflows are easily located after excavation,
particularly within machine bored sections. It is the intention of the Contract
Specifications that grouting be performed shortly after excavation so that
such inflows will be stopped before the pezometric level can be appreciably
affected over any sizeable areal area.
Two pump-out tests performed in the course of the subsurface investigations
failed to reflect any affect on observation wells as close as 75 feet away.
5-11
-------
This supports the contention of Foundation Sciences, Incorporated, Geologic
Consultant for the project, that intersection of joints will have an
extremely local effect on existing pelzometric levels.
During construction of a similar project, groundwater actually rose in
nearby observation wells, as a result of seasonal fluctuations. Also, on
that earlier project, one of the highest inilow areas was adjacent to a
quarry which was open and dry, further indicating the difficulty in predicting
groundwater loss or behavior in the localized area of the proposed tunnels.
It is anticipated that drawdown of the aquifer during operation of the
facility will be virtually zero. It is expected that grouting will reduce
groundwater flow into the tunnel to less than 300 gpm over the total length
of tunnels, based on results obtained with previous projects. The tunnel
lining will further reduce the inflows. Any openings in the lining which
permit significant groundwater inflows must be repaired. Any local drawdown
which may occur will be short-term, due to the tunnel tightness, and is
expected to return to the original piezometric level.
The design storm of July 1957 represents the most severe storm of the
21-year study period having a postulated frequency of occurrence of greater
than once in a 100 years. During this storm event, the predicted maximum
hydraulic gradient during peak runoff conditions for the ultimate system,
with reservoirs, will vary between evelation +23 (City of Chicago Datum) at
the downstream end to elevation +52 at the 16-foot tunnel upstream end. This
dynamic condition would last for less than one hour.
Immediately following the storm, the system will fill to static
evelation +52, which represents the maximum design surcharged conditions.
The length of time the water level within the tunnels will be at elevation
5-12
-------
+52 will be approximately 18 hours. Consequently, there may be a period of
approximately 18 hours that would occur with a return frequency of greater
than once in a 100 years, when the level in the tunnels would be slightly
higher than that of the surrounding groundwater.
Accurate data is not available on the groundwater levels, or its
seasonal fluctuations. The groundwater readings taken during the boring
program range too widely to be used with any arithmetical certainty. Since
the tunnels are being lined due to geological reasons, and since it is
believed that the tunnels can be maintained in a water tight condition,
computations have not been made which would quantify transmissibility
between the tunnel system and the aquifer.
The following criteria set up by the MSDGC with respect to the aquifer
monitoring wells will apply to the proposed project.
"To demonstrate that the project is not causing contamination of
the groundwater, it will be necessary to set up monitoring programs,
consisting of sampling wells with instrumentation to provide contin-
uous recordings of water level and the necessary equipment to extract
water samples for laboratory analysis. Instrumentation for recording
water level within the tunnel will also be required to obtain the
interrelationship between the groundwater levels and the tunnel
pressures.
"Samples will be tested for the following parameters:
pH NH -N Total Bacteria Plate Count
BOD Total Phosphorus Coliform (M.F.)
Chlorides Phenol Fecal Coliform (M.F.)
Hardness COD Fecal Strep. (M.F.)
Alkalinity Cyanide Conductivity
Mercury T.S.S.
Sampling will be performed at each of the wells at two-week intervals
and after each major storm event by the Research and Development Department
of the MSDGC. Monitoring wells will be installed at approximately one-half
to three-quarter miles along the line of tunnel at a minimum offset distance
5-13
-------
of 30 feet from the edge of the tunnel so as to be outside the grouted area.
Figure 5-5 shows approximate location of monitoring wells considered for
this project. In order to have continuous information of changes of ground-
water conditions and characteristics due to implementation of this project,
all monitoring wells should be in operation prior to tunnel excavation.
In response to the concern of certain citizens who experienced well
clouding during the soil and rock exploration program, it is noted that the
nature of the work performed during this program was quite different than
that to be done during construction of the tunnels and shafts. In the drilling
of the rock and soil borings, water was used, under pressure, to remove soil
and rock particles. This water pressure apparently caused a migration of
soil and rock strata which serves as a water source for private wells. The
nature of the construction operations will be such that, during excavation
of the tunnels and shafts, no net flow of water will flow from the construc-
tion areas, but in fact there will be a movement of water, or at least a
tendency of movement, into the excavation areas, thereby precluding the
possibility of groundwater contamination.
In areas of the tunnel where infiltration of groundwater into the rock
tunnels through bedding planes, faults or fractures is encountered, it will
be necessary to grout at these points. These openings will be sealed and
groundwater infiltration will be reduced, thereby insuring the maintenance
of the groundwater level above the tunnel and thus eliminating the possibility
of sewage from escaping into the surrounding rock. The grouting should have
no effect on nearby wells as it is performed with quick setting mixtures
and is thus kept in close proximity of the periphery of the tunnel.
In the event of any effect on groundwater quality, or potential clouding
5-14
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IIIIIIIIIIIIIIIIIIIIIIIIIIIHllltl
///, WATER RECLAMATION
W,. -IANT
MAIN^HAFT
LEGEND
ROCK TUNNEL
(APPROXIMATELY 150 FEET BELOW SURFACE)
Illlllllllll EARTH TUNNEL
(APPROXIMATELY 60 FEET BELOW SURFACE)
£ DROP SHAFT
MONITORING WELL
FIGURE 5-5
LOCATION OF MONITORING WELLS
5-15
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of wells, grouting operations will be stopped until remedial measures have
been taken to insure the necessary protection of the public.
D. Land
A map of existing land uses around the conveyance system has been
included in Chapter 2.
Without the conveyance system, existing conditions of sewer backups
and stream pollution from combined sewer overflows would continue. The
entire conveyance system is located underground with drop shafts and access
manholes at ground level; tunnelling will require the acquisition of easement
rights.
Some surface features of the tunnel project will be located in open space
areas. Further information needs to be acquired regarding disturbances
during and after construction in park and school properties.
Land use impacts as prepared by MSDGC, are included in Table 5-1.
Existing zoning and land use controls in the service area will impact future
growth. The anticipated growth of the area has been evaluated by MSDGC
and NIPC staff with varying findings. The capacity of the conveyance system
to accomodate future proposed growth is sufficient. Industrial development
has been forecast by MSDGC from 2000 acres in 1970 to 7300 acres in 2000.
At a meeting of the Planning Committee of the Regional Planning Commission
(NIPC), the NIPC staff indicated that industrial growth patterns would be
half of MSDGC's estimates. However, MSDGC contends that their evaluation of
NIPC documents, rate of industrial growth and expected growth would support
their projected industrial acreage figure.
NIPC planning papers do not include industrial acreage forecasts.
After a presentation by MSDGC to NIPC regarding this issue, the Regional
Planning Commission approved the MSDGC design capacity of the conveyance
5-16
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system and WRP.
Factors in addition to conveyance system capacity will result in
ultimate industrial development of existing vacant acres.
E. Air Quality
1. Construction Impacts
Construction would require the use of large vehicles and trucks,
generally driven with internal combustion engines with the resultant addition
of these air pollutants to the atmosphere. Under adverse weather conditions,
residents and animal populations in the immediate vicinity of the surface
construction activity could notice an air quality change. This would be a
temporary condition during construction, lasting no longer than three months
for access manholes, and 32 weeks fo1" the drop shafts. Total project
construction activity above and below surface and at the main shaft work
area would extend over a 42-month period. All of these effects, however,
are anticipated to be minor with the continued improvement in vehicle emission
control devices. Pollutant levels affecting construction workers, especially
those employed in the underground tunneling operations, will be within the
limits of the Federal Occupation Safety and Health Act (OSHA) standards.
Dust from construction activities at the surface sites could be signifi-
cant without proper controls. The mechanical ventilation systems used in
underground construction control the quality of exhaust discharged to the
atmosphere.
Dust raised by truck traffic will be minimized by using hard paved sur-
faces and dust control measures.
The amount of blasting and thus the volume of particulate matter that
could be emitted from the drop shafts due to blasting will be small and in
5-17
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low concentrations. The rock blasted in the shafts will be wet by ground-
water. In addition, it will, by necessity, need to be matted by rubber
tire or steel mesh mats prior to detonation of explosives, to prevent
release of high velocity particles.
2. Operational Impacts
Operation of the system will not produce particulate matter. No
adverse aerosol or water vapor effects are anticipated to be present in the
construction phase of any alternatives. During operation, the possibility
of aerosol generation and release from the operation of the drop shafts does
not appear to be a problem. As presently designed there should be no net
movement of air out of the drop shafts. During model studies there were no
observations of aerosolization. Should it be found that the actual drop
shaft operate differently, the openings to the surface could be easily
sealed without hydraulically affecting the structures.
A marked improvement in the residual odors reported in the Weller's
Creek area should result from the elimination of the combined wastewater
overflows. Construction activities should not create odor problems. No other
odor problems are anticipated. The conveyance facilities are designed to
maintain self-cleansing velocities to prevent deposition of solids and
consequent creation of odors so that there would be no detrimental effects
on the population in the vicinity of the drop shafts and manholes.
3. Mitigating Measures
Remedial actions to minimize air pollutants would include effective
enforcement of regulations regarding the operation and maintenance of
construction vehicles. A continued reduction of emissions from these vehicles
would result as provisions of the Clean Air Act are implemented.
5-18
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The levels of particulate matter resulting from blasting and excavation
could, if necessary, be reduced by scrubbing controlled exhausts of ventilating
systems, effective use of dust control water and chemicals, and cessation
of surface activities during adverse weather conditions.
Reduction of pollutants resulting form the operation of construction
equipment will require the constant surveillance to assure all operations
are consistent with MSDGC requirements.
F. Biology
The natural ecosystems along the tunnel route have already been
extensively altered or eliminated by human activities. The proposed
project will have short term adverse impact on terrestrial plants and
animals from the construction of dropshafts and manholes. Vegetation
removed during the project may be replaced to reverse this impact and
restore the habitat for animal life.
The aquatic ecosystems of Higgins Creek may be adversely affected by
siltation from construction erosion and by fluctuation of water temperatures
produced by the dewatering of tunnels. Detention ponds should greatly reduce
these problems. There should be no long term effect on the stream if species
are able to migrate into the affected area from upstream areas. The long
term effect of the project will benefit water quality and the stream biota
by greatly reducing combined sewer overflows.
G. Environmentally Sensitive Areas
Parklands will be affected by the manhole construction of this project.
This has been discussed with other impacts to area land use in Section D.
H. Aesthetics
Most of the tunnel construction will occur underground, reducing
its visual impact. Surface connections at dropshafts and manholes will cause
5-19
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a temporary adverse visual effect, which will be largely corrected when the
construction site is restored. Manhole covers, 26 inches in diameter, will
be visable at the ground surface upon completion of the project and replanting
of the sites. Dropshafts will each have two 47 inch outside diameter
manhole frame and cover castings, and one 3 foot 6 inch by 10 foot open
grate visable from the ground surface.
I. Noise and Vibration
Noise levels may reach 120 decibels during construction; however, most
noise will be intermittent and generally below 100 decibels. Noise will be
an adverse, short term impact. Mitigative measures will be taken to reduce
noise from construction equipment and trucks.
The operation of exhaust systems during construction might be considered
noisy and objectionable by nearby residents. Both working shafts are not in
residential areas, but are adjacent to heavily travelled roads such as the
Northwest Tollway and Rand Road; therefore, its impact should be minimal.
The tunnel depth should reduce any blasting vibration during shaft and
possible tunnel blasting. Blasting operations will be planned to maintain
particle velocities at less than one inch per second and vibration potentials
will be within permissible limits depending on the specific sites where
construction operations are planned. Information programs will prepare the
public for the unavoidable temporary vibrations and noise. Construction
schedules would take into account those hours of operation where noise would
cause the least disturbance. Use of moles will minimize these problems in
the construction of the tunnels themselves.
J. No Action Alternative
A no action decision would result in a continuation of the combined
5-20
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wastewater overflow during peak storms from the 29 outfall points within
Weller's Creek and Feehanville Ditch Drainage Basins. See Figure 5-4.
This condition, which presently occurs approximately 80 times annually,
would eventually be in violation of IEPA Regulations requiring this waste-
water to be directed to a treatment plant by December 31, 1977. The
flood hazard would continue to increase. The sewage generated within basin
would continue to flow to North Side Sewage Treatment Works through over-
loaded interceptors.
K. Summary
The proposed projects will result in a significant improvement in
environmental quality, with respect to the water quality of the local streams.
Construction of the projects will, hovever, result in the irretrievable
commitment of certain resources, such as concrete and energy. Once completed
however, the operational impacts will be practically non-existent.
The only long-term negative impact resulting from construction will be
the very localized soil compaction in the area of the construction shafts.
This impact cannot be considered significant when viewed in light of the
extensive land development and other construction taking place in the area.
Other negative impacts will be of a short-term nature. The turbidity of
Higgins Creek will be temporarily and periodically increased due to the
water pumped out of the tunnels during construction. In order to mitigate
this adverse effect, a detention pond (1/2 hour detention time) will be
provided to allow some settling of the materials. Construction vehicle
exhaust and dust resulting from vehicle operation will also temporarily
affect localized air quality. Given the magnitude of other air polluting
sources in the area, the incremental effect of this project will be
5-21
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insignificant. There will be some adverse impacts from the explosives used
in the construction of the tunnels. The noise vibrations at the surface
will be minimized by careful design and construction controls.
The most significant impact of the projects will be the improvement
in the water quality of Weller's Creek and Feehanville Ditch, which now
receive tremendous BOD and suspended solids Loadings from the 80 or more
combined sewer overflow events each year. The proposed projects will reduce
the number of overflows to 6 or less each year. While this is a significant
reduction, the ultimate objective is to eliminate all combined sewer overflows.
The MSDGC is presently examining various alternatives for dealing with the
remaining overflows. (See Figure 5-6.)
L. Findings
As a result of this EIS, we believe the following actions would serve
to increase the environmental compatibility of the proposed projects:
1. The Upper Des Plaines - O'Hare tunnel conveyance system can be
constructed as proposed, provided the necessary environmental
safeguards discussed in this EIS are implemented.
2. The MSDGC should take whatever steps are necessary, within their control,
to insure that the rock extracted during the construction of the conveyance
system is utilized in the most environmentally compatible manner.
3. The MSDGC should take additional reasonable measures necessary to
decrease the amount of siltation in Higgins Creek due to the water
pumped from the tunnels during construction. The possibility of increasing
detention time in the pond should be seriously investigated.
4. Once the conveyance system is in operation the drop shaft openings
to the surface should be monitored by the MSDGC for any significant
5-22
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FIGURE 5-6
MATRIX SUMMARY OF IMPACTS
AREAS IMPACTED ALTERNATIVES
Rock Tunnel
No Action Alternative
BEDROCK GEOLOGY
SOUS AND SURFIC1AL
GEOLOGY
Weathered Soils
Soil Compaction ^K
HYDROLOGY
Surface Water Quality Q Q
Ground Water Quality
Ground Water Quantity
Water Quahty-Higgens C reek I^M
AIR QUALITY
Vehicle Exhaust |^|
Odors 0 Q
Dual [B
Aerosols
ECOSYSTEMS
Wildlife Habitat f Q
' Rare and Endangered
Species
1OPOGRAPHY
CLIMATE
LAND USE
Landscaping I^Pi
Traffic Flow HH
Kethetic Appearance
(Surface Structures)
Permanent Easements
Combined Overflow Hazard ^P f~*\
NOISE AND VIBRATION
Noise 121
Vibration Kl
KEY:
B Negative Impact
No Impact
f_) Poaitwe Impact
I I Duration of Impact
is Temporary (Construction Period)
5-23
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odor and/or aerosol releases. If these are found to occur on a
regular basis, consideration should be given to the provision of
covers.
5. The MSDGC should fully evaluate alternatives to the combined sewer
overflow reservoir which may be built on site 2. The cost-effective
analysis of alternatives should specifically include the possible
interconnection to the main TARP system presently proposed.
5-24
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CHAPTER 6
FEDERAL/STATE AGENCY COMMENTS
AND PUBLIC PARTICIPATION
(This chapter will be completed after circulation of this
Draft EIS and the public hearing. It will be included in
the final EIS.)
6-1
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CHAPTER 7
SELECTED REFERENCES
Argonne National Laboratory, Energy and Environmental Systems
Division. August 1973. Airport Vicinity Air Pollution Study.
Brown and Caldwell. 1968. Design Report, O'Hare Reclamation Plant,
Metropolitan Sanitary District of Greater Chicago.
DeLeuw, Gather, and Co. 1972. Preliminary Plans for O'Hare
Collection Facility.
Flood Control Committee. August, 1972. Summary of Technical
Reports, Development of a Flood and Pollution Control
Plan for the Chicagoland Area.
Greeley and Hansen. 1962. Proposed West and Northwest Sewers,
Metropolitan Sanitary District of Greater Chicago.
Illinois Department of Transportation. 1973. Summary of Local
Planning Documents in Illinois.
Illinois Environmental Protection Agency. March 7, 1972. Water
Pollution Regulations of Illinois.
Metropolitan Sanitary District of Greater Chicago. November, 1973.
Appendix to the Environmental Assessment, Alternate
Management Plans for Control of Flood and Pollution Problems
Due to Combined-Sewer Discharges in the General Services
Area of the MSDGC.
Metropolitan Sanitary District of Greater Chicago. November, 1973.
Draft Environmental Impact Statement. A Plan for Control of
Flood and Pollution Problems Due to Combined-Sewer Discharges in
the General Service Area of the MSDGC. (Tunnel and Reservoir
Plan).
Metropolitan Sanitary District of Greater Chicago. November, 1974.
Environmental Assessment Statements for Proposed Projects
for the Upper Des Plaines Service Basin, O'Hare Tunnel System.
Metropolitan Sanitary District of Greater Chicago. December, 1974.
Facilities Planning Report. MSDGC Overview Report.
7-1
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Northeastern Illinois Planning Commission. 1971. Regional
Wastewater Plan.
Northeastern Illinois Planning Commission. September, 1974.
Regional Water Supply Report #8.
Walton. 1964. Future Water Level Declines in Deep Sandstone
Wells in Chicago Region, Illinois State Water Survey,
Reprint Series #36.
U.S. Department of Commerce, Bureau of the Census. 1970.
Census of Population, Numbers of Inhabitants, Illinois.
PC (DA15-I11-.
7-2
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
APPENDIX A
O'Hare Area Flood Control Activities
Design Criteria
Wilke-Kirchoff Reservoir, Project 70-407-2F
Heritage Park Reservoir, Project 68-815-2F
.White Pine Ditch Retention Reservoir, Project 72-313-2F
Buffalo Creek Retention Reservoir, Project 67-803-2F
WillowHiggins Retention Reservoir, Project 68-836-2F
Mount Prospect Retention Reservoir, Project 69-308-2F
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
WILKE-KIRCHOFF RESERVOIR, PROJECT 70-407-2F
The Wilke-Kirchoff Reservoir is a multi-purpose, excavated flood-
water retarding, pump evacuated reservoir constructed by the Metropoli-
tan Sanitary District of Greater Chicago, in cooperation with the
Village of Arlington Heights, at a cost of $871,000. The reservoir
occupies a 16 acre site, is 12 feet deep, ad has a storage capacity of
100 acre-feet. It serves a 717 acre tributary area and is designed to
accommodate a 100 year storm.
The Wilke-Kirchoff Reservoir is located south of Kirchoff Road,
and east of Wilke Road in the Village of Arlington Heights.
The reservoir was designed to serve as a recreational facility, in
addition to its primary function of reducing local flooding. Possible
winter activities include tobogganing and skiing on a large earth mound
in one corner of the reservoir formed with excavated material. Summer
activities can include such things as volleyball, basketball, baseball,
soccer, football, and a general play area. All recreational activities
are supervised by the Arlington Heights Park District.
The reservoir is excavated in a clay soil. The side slopes are
7:1, providing easy access to the bottom of the reservoir for recrea-
tional usage. The bottom and side slopes are sodded to prevent erosion
and to present an esthetically attractive appearance.
A pumping station, located at the northwest corner of the site con-
tains three variable speed pumps with a capacity of 6.67 cfs to 12 cfs
and two low flow pumps with a capacity of 0.33 cfs. These pumps can
empty a full reservoir in 6 days. Most storms, however, will not fill -
the reservoir completely, and the dewatering time will be less than 6
days. An underdrain system is provided beneath the reservoir floor to
remove the excess ground and storm water and thereby provide maximum
recreational usage of the reservoir bottom.
Storm sewers draining the tributary area carry the runoff into the
reservoir through two inlet structures. At low flows, the runoff drops
through a grate in the inlet structures and is conveyed to the pumping
station through the reservoir dewatering system. The multi-purpose use
of the reservoir is enhanced by use of th.e_low flow bypass system. The
water from the reservoir is pumped through a 30 inch force main to a
storm sewer that discharges into Weller_Creek, the natural drainage out-
let for the reservoir tributary area.
Construction of the reservoir began in August 1972, and was com-
pleted in the fall of 1973. The Metropolitan Sanitary District contri-
buted $736,000 of the construction cost and the Village of Arlington
Heights contributed $135,000. In addition, 'the Village 'of Arlington
A-2
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
i i
Heights paid $195,000 to acquire the reservoir site and also assumed
the engineering design costs. The Village will be responsible for the
operation and maintenance of the facilities.
A-3
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WILKE - KIRCHOFF RETENTION RESERVOIR
RESERVOIR - PROJECT NO. 70-407-2F
OUTFALL SEWER - PROJECT NO. 71-310-2F
SHEET 1 OF 2
DRAINAGE AREA 717 ACRES
DESIGN STORM 100 YR.
PUMPING STA. CAPACITY 36.7 c.f.s.
CONSTRUCTION COMPLETED
CONSTRUCTION COSTS $ 871.000
LAND AREA 14.6 ACRES
LAND COST $ 232,000
DRAINAGE
AREA S
- i
EXISTING STQRM
SEWER
VILLAGE OF ARLINGTON HEIGHTS
LOCATION MAP
METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
FLOOD CONTROL SECTION
JAN. 1973
A-4
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WIIKE - KlRCHOFF RETENTION RESERVOIR
RESERVOIR - PROJECT NO. 70-407-2F
OUTFALL SEWER - PROJECT NO. 71-310-2F
SHEET 2 Of 2
PUMPING STATION
30' GRAVITY
OUTFALL
RESERVOIR LAYOUT
in.
no
TO
m\
M
698
US
NO
675
Mt
6*C
n. STORAGE IN BASIN - 100 acre ft.
TOTAL STORAGE 100 acre ft.
RESERVOIR BASIN FIOOR (677 5' I
SEWER-* «- SEWER-' 21- SEWER-/ 24'
PUMP STATION
PROFJLE
STORM PUMPS #1. #2 & #3
VARIABLE - 3.000 to 5.400 gpm
6.67 to 12.0 cfs 100 hp
666.9' SUMP PUMPS #4 & #5
CONSTANT - 150 gpm - 0.33 cfs
7.5 hp
TOTAL PUMP CAPACITY - 16.500 gpm
36.7 cfs
OVERFLOW @ 689.5' elev.
PUMP CONTROLS - SPARLING - FLOAT
30" R.C.P.
GRAVITY SEWER
70S
700
695
890
885
680
675
870
665
660
73 F 539 R2
METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
FLOOD CONTROL SECTION
E.E.W. JAN. 1973
A-5
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
HERITAGE PARK RESERVOIR, PROJECT 68-815-2F
The Heritage Park Reservoir is a multi-purpose flood water reser-
voir constructed at a cost of $270,000 by the Metropolitan Sanitary
District in cooperation with the Village of Wheeling and the Wheeling
Park District. The reservoir is on a 25 acre site and has an average
depth of 5 feet. It has a usable storage volume of 112 acre-feet which
serves a tributary area of 447 acres and is designed to accommodate a
100 year storm.
The reservoir is an excavated storage gravity discharge structure.
The reservoir was designed as a multi-purpose facility for recreation,
in addition to its primary function of reducing local flooding. A per-
manent lake, about 8 acres in area and 5 feet deep, is provided to en-
hance the recreational features of the reservoir and usage for winter
activities. Tobogganing and skiing utilize a large earthen hill con-
structed east of the reservoir with material excavated from the reser-
voir. The adjacent park areas are utilized for all other seasonal
activities. Recreational activities are supervised by the Wheeling
Park District.
The reservoir side slopes are 4:1 or less, permitting easy access
to the reservoir bottom except for the permanent lake area. The reser-
voir area is grassed to prevent erosion and enhance the recreational
use.
The reservoir is emptied through a 60 inch diameter pipe into the
Wheeling Drainage Ditch. A flap gate on the 60 inch discharge pipe pre-
vents water from the drainage ditch entering the reservoir during peri-
ods of high water in the Wheeling Drainage Ditch. The flap gate also
restricts the flow of storm water out of the reservoir until flow capa-
city is available in the Wheeling Drainage Ditch.
The reservoir construction was completed in 1970. The Metropolitan
Sanitary District contributed $180,000 of the facility's construction
cost and the Village of Wheeling contributed $90,000 for the construc-
tion and paid the engineering design costs. The land for the reservoir
was provided by the Wheeling Park District.
A-6
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HERITAGE PARK WEST RETENTION RESERVOIR
PROJECT NO. 68-815-2F
<
DRAINAGE AREA 447 ACRES
DESIGN STORM 1QD YEARS
PUMPING STA. CAPACITY NONE
CONSTRUCTION COMPLETED 2-16-70
CONSTRUCTION COSTS $270,000 TOTAL (M.S.D. PAID f.
LAND AREA 25 ACRES
LAND COST (furnished by village) M
RESERVOIR
RO.
DRAINAGE AREA
DISCHARGE
PIPE
VILLAGE OF WHEELING
LOCATION MAP
i WHEELING RO.
j| RAILROAD
WHEELING DRAIN. DITCH
WATER EL 638.S WITH
10 YR. RUNOFF
MAX. WATER ELEV. IN
RESERVOIR 639.0
I > *w\
30^ \ ^ ,
. EL 634.7^ ^-EL 630.
PROFILE
METROPOIITAN SAHUMY DISTRICT
Of MUTER CHICAGO
FLOOD CONTROL SECTION
A-7
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
WHITE PINE DITCH RETENTION RESERVOIR, CONTRACT NO. 72-313-2F
The White Pine Ditch Retention Reservoir is a project of inter-
agency cooperation that will divert flow from the White Pine Ditch
Watershed to control chronic overbank flooding and sanitary aewer back-
up caused by storm flows entering and overloading the sanitary sewer
system. The need for additional public services tp assist people in
flooded areas, and the loss of direct access to or around flooded areas
with emergency equipment, is costly to the habitants in both life and
assets. Diversion of the existing and increased flows from the road im-
provement and urbanization will convey the flows to a reservoir site
with the capacity to store the excess storm runoffs. Along the water-
course no site could adequately provide the protection from the 100-year
storm event.
The Dundee Road improvement project, developed and under construc-
tion by the Department of Transportation, State of Illinois, includes
the larger sized storm sewer to divert flows from the White Pine Ditch
to the east. The discharge of this sewer and the naturally contributing
areas are directed into the retention reservoir of 50 acre-feet storage
capacity. The reservoir and White Pine both discharge into Buffalo
Creek.
The Village of Buffalo Grove reported the monetary flood related
losses for the year 1972 to be $50,700. These losses for the White Pine
Ditch area only involved 119 homes.
Cost involvement for the reservoir project are as follows:
$120,000 from the Metropolitan Sanitary District, $130,000 from the
Department of Transportation of the State of Illinois, and any addi-
tional cost by the Village of Buffalo Grove.
In addition to the construction cost for the reservoir, the Sani-
tary District will administer the construction contract and the Village
of Buffalo Grove will secure the land rights upon which the reservoir is
located.
The Sanitary District has authority to undertake this work and com-
mit funds without a general election. Plans and specifications were
awarded August 8, 1974. Work will be completed by May 1, 1975.
A-8
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WHITE PINE DITCH RESERVOIR
ORMMAl WHITE PINE DITCH DRAINAGE
AREA (585 ACRES)
WHITE PINE DITCH DRAINAGE AREA DIVERTED
BY HWHWAV IMPROVEMENT (315 ACRES)
r-J
Up! | / RESERVOIR BY M.S.D
-H*'! I / jSai dstail below)
STORM SEWER BY STATE HIGHWAY AGENCY
LOCATION PLAN
-> v )
I i 6th grit* by others
i
Ttk to by othtn
COtJSTBUCTION PLAN
A-9
2nd lee
1st green
IXHIKIT 3
METROPOLITAN SANITARY DISTRICT
OF GRtATER CHICAGO
FLOOD CONTROL SECTION
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
BUFFALO CREEK RETENTION RESERVOIR, CONTRACT NO. 67-803-2F
Urbanization of the Buffalo Creek Watershed has,increased storm
runoff and flooding in areas adjacent to Buffalo Creek and the Wheeling
Drainage Ditch in the Village of Buffalo Grove and Wheeling. To reduce
this flooding, the proposed Buffalo Creek Retention Reservoir will im-
pound approximately 700 acre-feet of storm water. This valley reservoir
will be an earthfill dam located just west of Arlington Heights Road and
south of Checker Road in Lake County. A culvert control structure will
pass low flows and limit the maximum discharge from the reservoir to ap-
proximately 250 cfs. An emergency spillway will be provided to pass
storm flows from storm events that exceed the 100-year storm event stor-
age capacity and to protect the dam structure.
Additional construction work includes a le'vee or other flood pro-
tection method for the private buildings adjacent to the reservoir site
north of Checker Road. Checker Road will be raised above the high water
elevation as will the new bridge over Buffalo Creek. The reservoir site
is approximately 160 acres located west of Arlington Heights Road in
Section 31 of Vernon Township, Lake County. The site also included some
area in Wheeling Township, Cook County. Total cost to the District is
estimated at $2,100,000.
Project implementation will be guided by a Cooperative Agreement
between the Lake County Forest Preserve District, Village of Buffalo
Grove, and the Metropolitan Sanitary District.
The reservoir site will be a multiple-use facility for open space
recreation uses, in addition to the primary function for flood control.
The Sanitary District has authority to undertake this work and com-
mit funds without a general election. Plans and specifications will be
available for bid advertisement in March, 1975. The construction con-
tract will be let within 90 days after bid advertisement. Work will be
completed by December, 1975.
A-10
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A-ll
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
WILLOW-HIGGINS RETENTION RESERVOIR, PROJECT 68-836-2F
The project includes the construction of two storm water retention
reservoirs, Willow-Higgins Creek Channel Modifications and Willow Creek
relocation to control the flooding in the Willow-Higgins Creek Watershed
for the 100 year storm event as shown on Exhibit 1. This provides for
storing flows from the 0'Hare Water Reclamation Plant that exceeds chan-
nel capacity. The reservoirs will be located in the O'Hare Airport run-
way clear zone areas. Clear zones are provided at the ends of runways
because of the high noise level in these areas, the need to control ele-
vation of structures in runway approaches and to provide for aircraft
over run conditions and thus are unavailable for individual public use.
The Ravenswood Reservoir site is located approximately 2750 feet
from the end of the runway 32R-14L and the Lee Street Reservoir site is
located approximately 900 feet from the end of runway 4L-22R. The
Willow-Higgins Creek Channel Modifications will be a closed concrete
section downstream of the Lee Street Site. The Willow Creek Relocation
will consist of both grass lined earth channel and closed concrete sec-
tions as physical conditions permit.
Willow Creek will be relocated generally along the western limits
of O'Hare Airport south of Old Higgins Road, and then northerly to the
Ravenswood Reservoir.
The project will relieve the flooding problems in the Willow Higgins
Watershed downstream of O'Hare Water Reclamation Plant for storm events
tfp to the 100 year frequency. Relocation of Willow Creek would facilitate
the future development of O'Hare Airport. Also, conveying the flow of
Willow Creek drainage area to the Ravenswood Reservoir, will effectively
utilize the greater storage capacity available at the Ravenswood site.
The flows added by O'Hare Water Reclamation Plant will be stored
at Ravenswood Reservoir when the flow in the downstream channel exceeds
the design capacity. These added flows will result from the treatment
of flows from an ultimate population equivalent of 439,000 in the service
area and also from the treatment of the storm flows from a combined sewer
area of 8000 acres located in Weller Creek Watershed, part of Upper
Des Plaines Tunnel and Reservoir Plan.
*
The proposed project would have following long terra effects:
1. Eliminate flood damages for storm events up to the 100-year
frequency and would provide peace of mind to the citizens
in flood prone areas.
2. Provide storage for additional flows from the proposed
O'Hare Water Reclamation Plant.
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO -
3. Facilitate the O'Hare Airport expansion program.
4. Use land located in clear zones for additional public benefit.
5. Increase property valuation by control of overbank flooding
and thereby increase real estate tax revenues, even with the
removal of some private land from the tax rolls for the project.
A-13
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
MOUNT PROSPECT RETENTION RESERVOIR, PROJECT NO. 69-308-2F
The reservoir will be an interim facility designed to provide a
certain level of protection to the area until such time as the Tunnel
nd Reservoir Plan is implemented. At that time, the reservoir will be
enlarged from 130 acre-feet (interim) to 850 acre-feet (ultimate). The
basin will function by gravity. No pumping will be required.
The interim plan involved 130 acre-feet of storage providing relief to
the upstream storm sewer system. The Village will be responsible for
the measures necessary to convey separate storm flows into the reser-
voir. Conversion to the ultimate facility will involve enlargement of
the reservoir and conveyance facilities to bring combined overflows
into the reservoir.
The interim facility will store storm flows only. The ultimate
facility will include measures to handle combined flows. The DeLeuw
Gather report, "Preliminary Plans for O'Hare Collection Facility", con-
cerns the O'Hare Tunnel and Reservoir system of which the ultimate fa-
cility will be a part. The interim facility is not covered in this re-
port. Detailed design and analysis of the interim proposal will com-
mence subsequent to the completion of negotiations with the Village and
the purchase of the site.
Drop Shaft No. 1 under the Tunnel and Reservoir Plan for the
(O'Hare) Upper Des Plaines Basin will be situated at Central Road and
Weller Creek. The 8,50 acre-foot Mount Prospect combined waste water
detention basin will function to limit the flow to Shaft No. 1 to 800
cfs. Based on a fully developed upstream drainage area, and an unre-
stricted upstream local sewer system (exceeding 100-year design storm
frequency), this flow was exceeded 24 times in the 21 year record period,
there were 21 times the maximum detention volume did not exceed 100 acre-
feet. Twelve times the volume detained did not exceed fifty acre-feet.
The maximum time of detention in the study period was 20 hours. This
was for a recurrence of the July 1957 storm. In general, the detention
period would be a small fraction of the 20 hour maximum even under full
development conditions.
A-15
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ARLINGTON HEIGHTS
Ave.
MT. PROSPECT
VILLAGE BOUNDA2Y
EXISTING M.S.O. SEWER
MT. PROSPECT
SITE OF PROPOSED
MT. PROSPECT
RETENTION RESERVOIR
CONTRACT 69-308-2F
THE METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
ENGINEERING DEPARTMENT
A-16
AUG., 1973
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THE METROPOLITAN SANiTARY DISTRICT OF GREATER CHICAGO
APPENDIX B
MSDGC TARP PROGRAM
Combined Sewer Overflow Elimination
The selected plan for eliminating untreated combined -iewer ove..-
flows or plant bypasses was chosen from various alternatives a~:d was
described in the August 1972 "Summary or Technical Reports,"
by the Flood Control Coordinating Committee. Since 1972 lo
to sub-systems of the plan have been made as additional s ndies an
sub-surface exploration work have been performed.
Tills chapter first describes the August 1972 Recommended Plan
and then describes the five revisions that have been made. These
revisions do not change the concept of the plan but only present
additional development of the-project to reflect sub~system optimiza-
tion.
August 1972 FCC Recommended Plan
Description and Maps
After extensive review of. the alternatives, the Flood Control
Coordinating Committee unanimously agreed that tbe Alternatives "G",
"H", "J" and "S" Mod 3, are less costly and would be more environ-
mentally acceptable to the community than any of the other plans
presented. Detailed studies and layouts along the lines of these
plans were then continued to develop the recommended plan.
The system recommended herein, a composite of several of the above
Alternatives, is outstanding in its relative storage economy and
simplicity. It will capture the total runoff from all of the record
meteorological sequences of history, if they were to recur on future
ultimate developed drainage basins, except for the peak few hours of
three of the most severe storm events. The system will convey these
captured combined sewer flows through high velocity, out-of-sight
underflow tunnels below the routes of the existing surface water-
courses to large pit-type storage reservoirs. Figure M-IX-1 shows
the general location of the conveyance tunnel system and storage
reservoirs.
The primary storage reservoir is shown located in the area now
occupied by the sludge lagoons of the Metropolitan Sanitary District
in the MeCook-Summit area. This reservoir will be in the form of a
300 to 330 feet deep rock quarry, with a maximum water depth of
approximately 200 feet, in the heaviest storm ;event,and water surface
dimensions averaging about 1,000 feet wide by 2 1/2 miles long. Total
storage capacity of the reservoir with the water surface as its
maximum level of -100 CCD, will be 57,000 acre-feet.
Figure M-X-2 shows the general layout of the reservoir, conduits
and pumping facilities. The lower 100 feet of depth of the reservoir
B-l
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
will be divided into three basins by transverse dikes, providing two
small basins, each with a volume of 5,000 acre-feet for t.he more
frequent small runoff periods. The larger runoff volumes will flood
the remaining basin and the water surface will rise in elevation over
the entire reservoir.
The dewatering pumping station shown on Figure M-X-2 will dis-
charge from the storage reservoir to the West-Southwest Treatment Plant
at an average rate of about 700 cfs. The station's total capacity
will be 2400 cfs in order to dewater the conveyance tunnels and Stearns
Quarry into the reservoir within two or three days following a storm.
Computer studies indicate that the storage utilized in Basins 1
and 2 will exceed their combined volume (10,000 acre-feet) at an
average frequency of six or seven times per year and that: these two
basins alone will entrap more than 70% of the annual combined sewer
spillage containing over 95% of the annual Suspended Solids.
The use of a deep pit storage basin of such magnitude and depth
requires that aeration be provided to insure positive odor control by
floating equipment. This is necessary because the range of liquid
level varies over 200 feet. It is proposed to use submerged turbine
aerators provided xvith a downflow draft tube with air injection below
the propeller.
The submerged turbine aerators will be provided with a bar screen
to prevent large ice chunks from being drawn into the draft tube and
damaging the blades. The aerators will be provided with legs to
protect the draft tube and will need a minimum of 20 feet of water to
operate. When floating at greater depths, it is considered that
active aeration will be limited to the upper 50 feet of the water in
storage.
Aerators, in the heaviest rainfall year will be in near continuous
operation in or above Basins 1 and 2. A lesser amount of aeration on
an intermittent schedule will be required in Basin No. 3.
An aerated reservoir of lesser depth and a volume of 1,800 acre-
feet, will be provided near the proposed O'Hare Water Reclamation
Plant, to serve the combined sewered area of the suburban communities
to the northwest.
Another reservoir will utilize the existing Stearns rock quarry
in the vicinity of 28th and Halsted Streets. This reservoir will
provide approximately 4,000 acre-feet of storage space and will be
used only during record storm events to flatten out the peak discharge
through the conveyance tunnels.
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
Conveyance Tunnels
There are approximately 120 miles of conveyance tunnels inter-
cepting 640 sewer overflow points in the 375 square mile area served
by combined sewers. Most of the conveyance tunnels will be construclt'il
in the Silurian Dolomite rock formation 150 to 300 feet beiow the
surface of the waterways. In some areas, the smaller tunnels will be
constructed in the clay overburden. See Figure M-X-3, 4 for profile---
of the tunnels.
The tunnels will in general be drilled by mining machine (moles),
except for the largest sizes which will probably be constructed by
the conventional drill and blast method.
Three main conveyance tunnel systems fork out from the primary
reservoir facility located in the McCook-Cummit area. See Figure M-X-1.
Figure MX-1. The Des Plaines Tunnel System extends north alone the
Des Plaines River to the Village of Des Plaines, thence northwest
terminating at the Village of Palatine. The Mainstream Tunnel System
extends under the Sanitary and Ship Canal, the North and South Branches
of the Chicago River and the North Shore Channel to the Wilmette
controlling works. The Calumet Tunnel System extends south and south-
easterly along public right-of-way to the Sag Channel, thence eastward
under the Little Calumet, Grand Calumet and Calumet Rivers to near the
State Line. The storage space in the conveyance tunnel system is
9,100 acre-feet.
Drop Shafts
The spillages will be delivered to the tunnels by hundreds of
vertical drop shafts, capturing the present spillage from the existing
riverbank sewer outlets of over five thousand miles of near-surface
sewer systems. A typical drop shaft is shown in Figure M-X-5.
The drop shafts will have a split vertical shaft, one side for
water and the other side for air. The center dividing wall will have
slots to insufflate air in the falling water. This reduces the impact
when the air-water mixture hits bottom. An air separation chamber is
provided to reduce the amount of air entering the tunnel. At the top,
a vent chamber will allow air to escape during filling and to be drawn
in during dewatering.
Groundwater Protection and Recharge
The major 'project elements are sited in rock units of the Silurian
System of the geologic strata underlying the Chicagoland area. These
limestone and dolomite rock units, together with the hydraulically
interconnected overlying glacial drift, comprise the so-called shallow
aquifer of the region which is recharged by local rainfall.
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
Additional data on protection of groundwater and limitation of
infiltration into tunnels and storage areas is available in Technical
Report No. 4, Geology and Water Supply. This upper aquifer system is
used as a water supply for individuals and certain municipalities.
However, the water supply for the vast majority of the area is through
piped systems using Lake Michigan water.
The preservation of groundwater quality and quantity is achieved
by positioning the project elements in the best available rock units,
taking advantage of the natural low permeabilities of the rock and
augmenting this low permeability by sealing the water bearing bedding
planes and joints, thus providing for elimination of the direct connec-
tions between the aquifer and the project element.
Additionally, the naturally high piezometric level within the
aquifer will provide a positive inward presssure providing additional
assurance against exfiltration of flows. In those areas were excessive
groundwater withdrawals occur, adversely lowering the groundwater
table, the added protection could be provided by artificial recharge
to restore high levels around the project element. The identification
of this recharge need, however, can only be made after sub-surface
exploration, testing and detailed positioning of the project elements.
Benefits
A brief listing of anticipated benefits to be derived from
completion of the system of flood and pollution control proposed
herein, includes the following:
1. Protection of the valuable water resources of Lake Michigan
from flood release of river water as now required through
the existing Chicago River, the North Shore Channel and
the Calumet River into Lake Michigan.
2. Achieving and maintaining acceptable water quality (in
accordance with National Goals and Regulations of the
Illinois Pollution Control Board and the Metropolitan
Sanitary District) in the open waterways known as the
Chicago River and its branches, the Sanitary and Ship
Canal, the North Shore Channel, the Calumet-Sag Channel
and those portion of the Calumet River, Des Plaines River,
Salt Creek and other open waterways, under the jurisdiction
and control of the Metropolitan Sanitary District of Greater
Chicago.
3. Reduction of surface and basement flooding by underground
backwaters or overbank flooding.
B-4
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
4. Improvement of recreational values of all surface waterways.
5. Increase in property values due to general improvement of
environment.
Additional Plan Developments
The plan described in previous sections was produced in 1972.
The intervening two years have provided the opportunity to incorporate
new analysis and information, and improve the Plan accordingly. These
up-dates can be grouped under five headings, with the revised Recommen-
ded Plan shown on the attached m^p (Figure M-X-6).
a. Independent Calumet System: The most significant revisions are the
separation of the Calumet Area from the Central System and having an
independently operating system with dewatering to the Calumet Plant.
, The decision to separate the Calumet Area was based on detailed
study ' of operational flexibility and cost. This study originated
with the recognition that several potential reservoir sites exist in
the Calumet Area, and the cost of the 55,000-foot connection tunnel
($100 million) would be saved by independently operating systems.
The study considered three alternative concepts, each with
several variations:
A. Maximum Size Intertfe Tunnel Plan; In this plan, no
storage would be provided in the Calumet area. All flow would be
directed to the McCook-Sutnmit area terminal reservoir. Economies
would be realized by concentrating terminal reservoir facilities.
These savings would be compared to the extra costs associated with
conveyance facilities required to concentrate the storage.
This scheme is similar to the layout shown in Figure M-X-1 (tS
Recommended Plan from the Summary of Technical Reports) for the
project area remaining after exclusion of the O'Hare sub-project area.
However, these studies included drainage flow from the communities of
Lansing and part of Markham which were not a part of the prior studies
made in support of the Summary of Technical Reports. This additional
drainage flow is included as well in all other alternatives evaluated
in this study.
An Intermediate Size Intertie Tunnel Plan. Storage would
be provided in the Calumet area but it would be an amount which would
be insufficient to accommodate all of the runoff in the Calumet area
during a large storm. In these instances, the Calumet area reservoirs
would fill and, subsequently, flow would be diverted through the
intertie tunnel to the McCook-Summit area reservoir.
B-5
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THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
No Intertie Tunnel Plan. In this scheme, storage volume
provided in the Calumet area would be sufficient to accept the excess
combined sewer flow in that area. The Mainstream and Des Plaines Tunnel
Systems would drain to the McCook-Summit area terminal reservoir.
Several variations within each of the above basic concept planr
are possible and were examined in this study so that the l_east-cost
representation of each of the above concepts could be identified. This
led to development of twelve separate project layouts for comparative
evaluation, which included different reservoir locations and tunnel
systems.
Initial Evaluation of Project Layouts; The evaluation and cost estima-
ting methods employed in the initial phase of this study are identical
to those used in the studies which are reported in the Summary of
Technical Reports. The same basic unit costs and cost curves were
used as were the computer programs previously developed. These were
accepted and used to conduct simulation studies which yielded results
concerning performance of the twelve project layouts. A "trial and
error" procedure was employed in the development of these layouts
wherein tunnel diameters and reservoir sizes were first assumed; then,
for selected storm events, the system performance was simulated by
electronic digital computer cooperation; and system performance defi-
ciencies were noted upon completion 'of the computer run. Adjustments
were then made in tunnel diameters and reservoir dimensions as
indicated by the simulation analysis results. The procedure was
repeated until all of the twelve project layouts satisfied the perfor-
mance requirements. These performance requirements were to limit
the overflow quantities during repeat of the largest storms to prevent
hackflow to the Lake and to treat the captured water at the existing
treatment plants at a rate such that the total flow to the plant
combined with dry weather flow did not exceed 1.5 times average dry-
weather flow. The estimates of costs of construction of the sanitary
systems were compiled using the cost parameter data developed for the
prior studies.
The general approach employed in the initital evaluation phase
of this study is presented here. The prior studies which are described
in the Summary of Technical Reports showed that, of the 21 year
continuous record of precipitation, a tunnel-reservoir system which
functioned adequately in simulation analysis during the events of
July 12-13, 1957 and October 3-12, 1954 would also function satis-
factorily throughout the remainder of the period of record. Further,
the tunnel sizes required in any given layout were dictated principally
by conditions which prevailed during the 1957 storm; a storm which
yielded the maximum instantaneous peek runoff flow. Also, the prior
studies showed that the total reservoir storage volumes required
were controlled by the conditions which obtained during the 1954 storm.
B-6
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
Moreover, an approximate correlation existed between the reservoir
requirements established by simulation of the 1957 storm and those
established by simulation of the 1954 storm.
For these initial evaluation studies, only the July 12-13, 1957
precipitation event was used in simulation analysis step of the work.
This was made necessary because of the large number of computer runs
required and the especially lengthy run-time of the 1954 event simu-
lation. The July, 1957 analyses yielded the required tunnel diameters
of the several schemes. The construction costs of these tunnel network-
were computed. The July, 1957 analyses also indicated reservoir volume
requirements for satisfactory system performance for this event.
These values were extrapolated to approximate total reservoir volume
requirements which would be needed for satisfactory system performance
during the Oc.tober, 1954 storm. Reservoir construction cost estimates
were then developed.
Cost comparison of the twelve alternatives was made on the basis
of the sum of the tunnel and reservoir costs. These were regarded as
the controlling project costs since these two project compontents
comprise approximately ninety percent of the total construction cost.
Additionally, much of the remaining 10 percent of construction costs
consist of modification of surface collection facilities and drop
shafts, both elements being a common and near-constant cost factor for
all proposed systems.
"Least Cost" Alternatives - Detailed Evaluations; The maximum size
intertie tunnel plan (Scheme 1A), the intermediate size intertie
tunnel plan (Scheme 2E), and the no intertie tunnel plan (Scheme 3A),
having been identified as the most economicaly systems for each of the
three concepts, were examined in greater detail than the remainder of
the alternatives. Each of these schemes include the use of existing
quarries as reservoirs. These quarries, already having depths in
excess of 200 feet and large volumes available, had distinct advantages
over other sites with no significant existing storage volume such as
in the sludge lagoon sites. Preliminary reservoir layouts were made
for these plans and more detailed construction cost estimates were
prepared as shown in Table M-X-1.
The totals show the cost advantage of 3A, separation. Addi-
tional advantage is found in the freedom of construction phasing.
B-7
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
TABLE M-X-1 LEAST COST SCHEMES ESTIMATE OF CONSTRUCTION COSTS; MILLIONS
OF DOLLARS (Based on a Limitation of Stockpile Height of
200 Feet in the McCook-Summit Area) ,
_ Sum of Tunnels and Reservoirs (1972 Costs, Unescalated) _
Item Scheme 1A Scheme 2E Scheme 3A
2
1. McCook-Summit Reservoir 496 351 286
2. Thornton Reservoir - 56 74
3. Mainstream On-Line
Reservoir 15 15 15
4. Tunnels1 691 568 552
5. Pumping Stations
a. McCook-Summit 71 65- 64
b. Stearns Quarry 8 8
c. Thornton-Calumet _ ^ 30 30
TOTAL, without contingencies 1,281 1,093 1,029
^Estimates of tunnel cost require a determination of whether or r>ot
they are concrete-lined. The final decision concerning concrete
lining must be reserved for the design phase of the project and
completion of subsurface investigations. This decision cannot alter
the conclusions of this optimization study because all project:
layouts will be similarly affected.
^Includes credit for future sale of rock and other future land values.
B-8
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
As a result of these studies, the interconnecting tunnel has been
eliminating and planning and subsurface explorations have been concen-
trated on development of the plan with an independently operating
Calumet System.
b. Palatine Tunnel Elimination
An additional revision is the elimination of a tunnel leg into
the Village of Palatine. A report titled "Preliminary Engineering
Study of Palatine, Illinois for Intercepting and Holding Combined-
Sewage Overflows" was completed in September, 1973. Eighteen alternate
solutions were studied. The lowest cost alternate for a tunnel and
reservoir concept system for Palatine area to connect to the O'Hare
System, as originally proposed was $22,700,000. Of the alternates
discharging to Salt Creek Water Reclamation Plant, the lowest cost was
$17,300,000; however the recommended tjnnel and reservoir concept
system was estimated at $18,900,000. It was further established that
construction of a separate new five-year storm sewer system for the
combined-sewer area would cost $11,100,000 and the construction of a
new sanitary sewer system would cost an estimated $12,700,000. Either
a new storm sewer system or new sanitary sewer system would eliminate
combined-sewer overflows in this drainage basin.
At the regular Board Meeting of April 22, 1971, the Board of
Trustees of the District approved the U.S. Soil Conservation Service
Upper Salt Creek Watershed Work Plan. This plan, of which the District
is a local sponsor, is a comprehensive program which will prevent
overflow of Salt Creek in the Palatine area. The District has already
committed $4,861,000 for seven projects under the Work Plan. In view
of this program, the flood control benefits of the District's Tunnel
and Reservoir Plan for the Palatine area will not be required.
The estimated cost of the tunnel and reservoir plan exceeds the
estimated cost of separating sewers within that portion of the Village
of Palatine which has combined-sewers; and therefore, the tunnel and
Reservoir concept is not the cost-effective method for preventing
discharge of combined-sewage to the waterways.
Therefore, the Palatine tunnel leg in the Northwest Area of the
District has been eliminated and at meetings with the Village of
Palatine the Village Officials have been so informed.
c. Mainstream Dual Tunnel System
A third revision or updating includes dual tunnels for the
Mainstream System from Summit to Lawrence Avenue. The August 1972
Plan included a 42-foot diameter or equivalent along this reach. In
order to maintain a uniform slope, this tunnel would have to be constructed
through the Maquoketa shale. This shale formed from clay sized
B-9
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
particles is a softer rock than the dolomitic limestone, and presents
different stability considerations for both long-term use and during
construction. Thus, the construction in this shale will be more costly
than in limestone.
During 1974, additional rock borings have been made to further
identify the location of this shale formation and additional analysis
have been performed. As a result, it has been determined that the most
cost-effective plan is to construct a smaller tunnel first at the
required slope and at a latter date construct a second tunnel which
vould be totally in the limestone formations. Each of the dual tunnels
would provide one-half the required conveyance capacity.
B-10
-------
TABLE
inc. iw c i nwrwui i MI* oMniiMni uioinii^i
M-X-2 TUNNELS MAINSTREAM SYSTEM (McCook
v/r u r> c. M i c. n v* n e v* M u V
I
to Confluence)
SINGLE TUNNEL
LINE
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
49
50
LENGTH
7,095
13,575
8,00
8,600
7,332
8,368
10,992
11,718
8,285
4,095
5,451
4,104
3,823
2,865
24,400
11,300
14,580
DIA.
42
42
42
42
42
42
42
42
42
42
42
42
42
42
SUBTOTAL
TOTAL
Cost
shown exclude shafts
COST
$ x 1000
:? JL/,UUU
15,600
29,800
17,600
18,900
16,100
18,400
24,100
25,700
18,200
10,800
11,900
9,010
8,390
6,290
$247,790
$247,790
, connecting
Dia.
33
33
33
33
33
30
30
30
30
30
30
30
30
30
30
structure
DUAL TUNNELS ;
Stage I Stapp '
COST DIA. CO,
ft x 1000 $ x
10,820 35 7,810 \
20,700 35 14,930
12,200 35 8,800
13,120 35 9,460
9,750
11,130
14,620
15,590
11,020
6,520
7,250
3,650
3,400
2,550 35 3,150
35 26,840
35 12,430
35 16,038
$152,890 $110,958
$263,848
and contingences
B-ll
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
The Table M-X-2 compares the construction costs of the single tunnel
with the costs of the dual tunnel system. As can be seen the cost
difference is $16 million or 6 per cent of the total. This difference
is insignificant when considering the total costs of the program. There-
fore, also considering the uncertainties of grant funding, the dual
tunnel system is chosen because the first tunnel can be constructed at
a lower initial cost and provide for the capture of in excess of 80 per
cent of the pollutants now discharged to the waterways, and thus obtain
an early return on the invested funds. The dual tunnel system also
offers time to further optimize the size needed for the second tunnel
to meet project objectives.
d. Mainstream On-Line Reservoir
Another revision has been elimination of Stearns Quarry as the
location of the Mainstream On-Line Detention Reservoir. This reservoir
has been included in the Plan in order to reduce the size and cost of
the Mainstream Tunnel System. Without such a reservoir, the lengthy
Mainstream Tunnel would have to increase in size from a 42-foot diameter
equivalent tunnel to a 55-foot diameter equivalent tunnel'^',
The Stearns site is now being filled in and will eventually
be used as a park. The previous studies had considered this site only
in relation to evaluating different alternatives of solving the combined-
sewer overflow problem, and not in terms of the specific details of the
site. It has now been determined that the best and highest use of the
site is as a park.
In its place, a Mainstream On-line Reservoir at an unidentified
site is included. The location of this reservoir can be anywhere along
the tunnel between the Stearns site and Wilmette Harbor. Since this
reservoir will be used only during the large storms of record to reduce
the peak flow rates to the tunnels, it will be one of the last facilities
to be constructed. If a suitable site is not found for the reservoir,
the alternative does exist to increase the size of the second tunnel of
the Mainstream Dual Tunnel System.
e. Des Plaines Watershed
A fifth revision provides for the total capture of the combined-
sewer overflows in the Des Plaines River Watershed. The August 1972 Plan
included the equivalent of a Mod 3 level of capture for the sizing of the
Des Plaines River Tunnel and the O'Hare Northwest System. However, as
was stated in the report, total captvire would be needed in order to meet
the higher water quality standards of the General Use and the Public and
Food Processing Water Supply Designated waterways. (See Figure M-X-7.)
This was the case in the Little Calumet River and the North Branch of
the Chicago River Upstream with its junction with the North Shore Channel.
Tunnel sizing is provided so as not to spill into these waterways.
B-12
-------
THE METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO
The higher water quality standards for the above waterways includes,
among others, the requirement that the dissolved oxygen level shall not
fall below five milligrams per liter at any time. The computer simu-
lation of the overflows into the Chicago and Calumet River Systems
(designated as secondary contact waters) demonstrates that depression of
the oxygen levels below five milligrams per liter will occur. Since ther^
latter waterways have a lower water quality designation and instream
aeration is to be provided the Mod 3 level of protection is judged to be
adequate. However, it is not judged to be adequate in the Des Plaines
River Watershed. A computer model of the Des Plaines River has not been
developed as for the above waterways. However, the same level of contami-
nants would be discharged during overflow and the results can be expected
to be the same.
Therefore, the plan now includes reservoir capacity in the O'Hare
Area to provide for total capture and increased sizing in the Des Plaines
River tunnels to transport a higher rate of flow to the Mainstream-
Summit Reservoir.
In the O'Hare Area, the August 1972 Report provides for an 1800
acre-foot reservoir including capacity for Palatine. Subsequent
Analysis &' demonstrates that 1280 acre-feet is required for the
equivalent of Mod 3 level storage for the O'Hare sewered area and 2700
acre-feet for total capture. Provision for the latter quantity of storage
is being included in the Plan. The sizing of the tunnels is not changed
because of the decision to include total capCure. The tunnel size has
been chosen to transport dry-weather flows to the O'Hare Plant, and on
the basis of transporting peak storm flows wi.lh an On-line reservoir
providing for the detention of peak flow rates so as to control the tunnel
surcharge. The cost of both the 2700 acre-foot O'Hare terminal storage
reservoir and the On-Line reservoir is included in the Plan.
The Des Plaines River Tunnel has been increased in size to provide
for total capture. This size increase is shown on Table M-X-3. The
original size was picked such that spillage to the waterways occurred
during a repeat of the July 1957 storm, (the storm of record for rate of
flow) at approximately the same ratio to total flow as in the Chicago
and Calumet River Systems: During the 1954 storm (the storm of record
for total volume), there was no spillage to the Des Plaines River and the
total flow was transported to the reservoir. Thus, no additional storage
volume is needed to provide for total capture and only increased tunnel
sizing is required.
B-13
-------
inc. w c. i nwr uui i MII oMitiiMni uioimui ur ontMltn uniUAUU
TABLE M-X-3 TUNNELS- DES PLAINES RIVER SYSTEM
LINE LENGTH TOTAL CAPTURE
(ft.) DIA. (FT.) COST
($ x 1000)
18 8800 36 15,224
19 5040 15 2,974
20 11,280 10 3,948
21 9460 36 16,366
22 12,200 32 17,690
23 11.200 15 6,608
24 8160 32 11,832
25 14,390 32 20,866
26 5100 32 7,395
27 8600 24 8,600
28 7050 24 7,050
29 10,380 24 10,380
30 6470 24 6,470
TOTAL 11 ft, 130 135,403
Cost shown exclude shafts, connecting
MoD 3 LEVEL PROTECTION
DIA. (FT.) COST
($ x 1000)
30 11,704 ,
15 2,974
15 6,655
30 12,582
25 12,810
15 6,608
25 8,568
25 15,110
25 5,355
25 9,030
25 7,403
20 8,304
20 5,176
112,279
structures and contingencies
B-14
-------
THE RECOMMENDED PLAN
AUGUST 1972 V
STORAGE
RESERVOIRS
O TREATMENT
WORKS
FIGURE M-X-1
B-15
-------
><
oe
=3
O
DEVELOPMENT OF A FLOOD AND POLLUTION
CONTROL PLAN FOR THE CHICAGOLANO AREA
PART 5 - ALTERNATIVE SYSTEMS
PRELIMINARY LAYOUT OF STICKNEY RESERVOI
B-16 DECEMBER. 1972
-------
I»CUS«NOS Of Fill 0 10 20 30 40 50 tO 10
STORAGE SANITARY AND SHIP CANAL SOUTH
ao 90 too no
NORTH CHICAGO RIVER
NORTH SHGRf -,','il
RESERVOIR
CHICAGO RIVER
MAINSTREAM SYSTEM
* 1 e |5
I h j a1
»J?i 1UM8IH-* ) 7 33 36 37
! ! 1 i
i 1 ' ;
*1GO *
1 1
I I i
39 *0 '
! I
1 1
i
iils
|
l
i
5" M J
45 4G 4E
t
! ' ,__^._*-r""
-400
THOU5ANOS 0' HC 0 W 20
STORAGE _
RESERVOIR
40 50 60 10
OES PLAINES RIVER
MBq^kc a i-ui-
100 110 120 130 UO
O'HARE AREA PALATINE BRANCH
DES PLAINES RIVER SYSTEM
P
h
-J- "
. Si i II ia
II I! J I! II
-100
-200
0 10 'O 30 40
NORTH BRANCH CHICAGO RIVER
05 05
CHGO SOUTH
RIVER FORK
MAINSTREAM BRANCHES
i \ ill ill
I * S £ 1 1 .
3 34 35 37 38 0
1
LV fttf
^
.
I
2GO
100
0
-too
-203
-300
10 20
SALT CREEK BRANCH AOOISON
CREEK
FEEHANVIUE
DITCH
DES PLAINES RIVER BRANCHES
TUNNEL PROFILES
B-17 FIGURE M-X-3
-------
NODE NUMBER 12
100
p
o
o -100
Z
o
< -200
UJ
300
-400
Silunan Dolomite -
iure
ytt''"tod s" ' -\ !!""" !["~^"oi.7i"
30' Dio IT i
/CO
THOUSANDS OF FEET 0
STORAGE HARBOR BELT
30 40
HARLEM AVE.
50
RESERVOIR ' R.B.
4-
60 70 80
CAL. SAG CHANNEL
so
100
LIHLE CALUMET
no
CAL.
- ---320
120
GRAND
-400
RIVER CALUMET
CALUMET SYSTEM
X gj
» s ;
I i
£ =i
1 _i g
' . m B 5 S
I 1 II a 1 1 I ?
£* CO ?-. no S- too
NODE NUMW1 27 20 21 22 23 24 25 24 31 3
O
o
X
o
< -200 .
LLJ
THOUSANDS OF BET
--1 1_ _ _, pl__l
1
75' Olo. 2
_, '-
»» «-^
1 10
Siliiddi Dolomite
0- Dla. I/' Dia. 1S' Pl°'-
1
1
L
,
20 30 40
LITTLE CALUMET RIVER
V .
1
- -..__!_
i^
IS' Dlo. 1
1 10
YTERCONNECTIDN
CALUMET BRANCHES
TUNNEL PROFILES
FIGURE M-X-4
B-18
-------
VENT CHAMBER
ENTRANCE
CHAMBER
CONNECTING PIPE
WATER SIDE
TOP OF ROCK
AIR SEPARATION CHAMBER
ROCK TUNNEL
TYPICAL DROP SHAFT STRUCTURE
FIGURE M-X-5
B-19
-------
TUNNEL AND RESERVOSR PLAN
I eo<
*
-1*
A ON-LINE RESERVOIR
ROCK TUNNEL
0 STORAGE
RESERVOIRS
a TREATMENT
WORKS
,.!/ COUf
B-20
NOV. 1974
-------
!" B Ufl
THE METROPOUTAN
SANITARY DISTRJCT
OF GREATER CHICAGO
r"-,..;.
GEN. USE AND WATER SUPPLY ^
GEN. USE ONLY
! SECONDARY CONTACT
TREATMENT PLANT
v ^
r «««_«!
METROPOLrrAN CHiCAGO
FIGURE M-X-7
B-21
-------
APPENDIX C
THE METROPOLITAN SANITARY DISTRICT OF Grt£ATER CHICAGO
POSITION PAPER ON SELECTION OF
UPPER DESPLAINES SERVICE BASIN PLAN
OVER OTHER SUGGESTED ALTERNATES
The O'Hare Facility Area (Upper DesPlaines Service Basin)
is a 58 square mile area in 'the northwest region of the
Metropolitan Sanitary District. At present, all sanitary sewacie
and the combined sewage finding its way into District inter-
ceptors through regulated control structures, is diverted
through existing interceptors to the District's Northside
Sewage Treatment Works for treatment. Initially, following
annexation into the District of most of the area in 1956,
it was planned to transmit sewage flows for the District's
northwest area to the West-Southwest Sewage Treatment Plant
in Stickney for treatment. However, further study indicated
the cost-effectiveness and desirability of dividing the north-
west area into four (4) service areas. This Paper gives, in
detail, the planning history and rationale of dividing the
northwest area of which the O'Hare Facility Area is a part,
into four (4) facility (service) areas.
Collection and treatment of sewage generated in this
basin has been the subject of many studies and reports. In
1961, the Sewer Design Section of the Metropolitan Sanitary
District recommended that the Northwest Intercepting System
be constructed to relieve existing sewers in the northwest
portion of the District to provide service for the ultimate
development of that area (Ref.1). The northwest area comprises
the O'Hare, Salt Creek, Hanover Park and Poplar Creek (Elgin)
Facility Areas as shown in Figure 1. The consulting firm of
Greeley and Hansen was-retained to investigate this proposal.
Based on their report, submitted in 1962, a tentative decision
was made to convey all sewage from the area to the West-Southwest
Treatment Plant (Ref.2). Further investigation of this proposal
indicated that the cost and magnitude of the project would
require such time and resources as to necessitate construction
of temporary plants in the northwest area (Refs.1,2). Additional
studies and investigations carried out primarily due to the
trend toward higher standards for disposal of treated effluent,
indicated the advisability of collecting and treating the
sewage from each facility area in the northwest area separately,
since construction of temporary tertiary treatment plants, of
the magnitude indicated, would not be cost-effective (Ref.3).
Furthermore, the District considered that diversion of substantial
quantities of water from the northwest area would not be conducive
to water reuse. The utilization of tertiary quality effluents for
stream augmentation, within the area, was considered to have
c-i
-------
C-2
-------
environmental and recreational benefits. The Northwest Inter-
cepting Sewer proposal would have diverted all sewage flows
from the area for treatment at West-Southwest Treatment Plant
and treated effluent would be discharged into the Sanitary
and Ship Canal at Stickney.
As a consequence, the Northwest Area was divided into
Facility Areas corresponding to existing drainage basins:
Upper DesPlaines Service Basin, O'Hare Facility Area; Upper
Salt Creek Service Basin, Salt Creek Facility Area; Upper
DuPage Service Basin, Hanover Park Facility Area; and Poplar
Creek Service Basin, Poplar Creek (Elgin) Facility Area.
A preliminary design concept for the O'Hare Water Reclama-
tion Plant and intercepting sewers was prepared in report form
by Brown and Caldwell, consulting engineers, in 1968 (Ref.4),
The contract plans for O'Hare Water Reclamation Plant have been
prepared by Consoer, Townsend and Associates, consulting engineers,
and are presently under review by the District. Preliminary plans
for two (2) collection facilities systems were prepared in a
report by DeLeuw, Gather & Company, consulting engineers (Ref.5).
One system would divert total sanitary sewage flow only within
the basin to the O'Hare Water Reclamation Plant; the second
system would convey all sanitary sewage to the plant but would,
in addition, eliminate combined sewer overflows by collecting
and storing for treatment, all combined sewer overflows presently
discharging to waterways within the drainage area. They are
presently developing contract plans for the O'Hare Tunnel System
as part of the second system.
In 1973, The Corps of Engineers published the Chicago-South
End of Lake Michigan Study (Ref.6). The investigation included
the O'Hare Facility Area and the O'Hare Water Reclamation Plant
was defined in three of the five alternates presented in the
Report.
Northeastern Illinois Planning Commission (NIPC) included
the District's plan for the O'Hare Facility Area in its "Regional
Wastewater Plan" in 1971 (Ref.7). This plan has been revised a
number of times since (Refs.8,9,10,11,12) but revisions have not
affected the O'Hare Facility Area except to include the District's
Tunnel and Reservoir Plan as a regional solution to the combined
sewer overflow problem. The first three NIPC Plan revisions have
been certified by the State of Illinois and the Federal Government
in accordance with 40 CFR 35.565 (Refs.8,9,10).
The review of the planning history indicates that the
division of the District's Northwest area into four facility
areas is cost-effective and environmentally sound and has been
c-3
-------
recognized by NIPG, the State of Illinois and the Federal Government.
The District's comprehensive plan calls for collection and treatment
of sewage within each facility area separately. For the O'Hare Facility
Area, the District has planned a collection system designated as O'Hare
Tunnel System and a treatment facility, O'Hare Water Reclamation Plant.
It is, therefore, clear that the selection of the Upper Des Plaines
Service Basin Plan over other alternates suggested was a sound judgment,
based on a number of detailed engineering studies concurred in by a multitude
of governmental agencies. Based on the results of the studies and
concurrence of the applicable regulatory and planning agencies, as well
as the majority of the affected communities, decisions have been, made ami
actions taken over a number of years which weigh even more heavily in
favor of continuing the proposed course of action as- expeditiously as
possible. The initiation of new studies and reconsideration of numerous
alternates suggested by individuals untrained in the relevant fields of
endeavor and uninformed in the history of past decisions and the multitude
of facts and data drawn upon in making these decisions is unwarranted.
C-4
-------
REFERENCES:
1. MSDGC, "Recommendation for Site Acquisition
for Additional Sewage Treatment Plants for
Northwest Section.of Cook County, Salt Creek
and DesPlaines River Areas," June 25, 1964
2. Greeley and Hansen,"Proposed West and Northwest
Sewers," MSDGC, 1962
3. Greeley and Hansen, "Report for Northwest Area",
MSDGC, 1968
4. Brown and Caldwell, "Design Report, O'Hare Re-
clamation Plant", MSDGC, 1963
5. DeLeuw, Gather & Company, "Preliminary Plans for
O'Hare Collection Facility", MSDGC, 1972
6. Corps of Engineers, "Chicago South End of Lake
Michigan Study", Chicago District, 1974
7. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", March, 1971
8. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", Revised September, 1971
9. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", Revised October, 1971
10. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", Revised January, 1972
11. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", Revised July, 1972
12. Northeastern Illinois Planning Commission,
"Regional Wastewater Plan", Revised October, 1972
C-5
-------
APPENDIX D
BEDROCK GEOLOGY
This description of the general bedrock geologic conditions
in the study area is complemented by the analysis of field borings
as reported in The Geotechnical Report on the Upper Des Plaines
Tunnel and Reservoir Plan, Volume 1, Bedrock Geologic Invest i -
gation, 1974, De Leuw, Gather & Company.
The limestone and dolomite rock units, together with the
hydraulically interconnected overlying glacial drift, function as
an aquifer.
Rocks in the project area date back to the Upper Ordovician
Period. They consist of mudstones, argillaceous dolomite, pure
dolomite and unconsolidated or semi-consolidated glacial deposits.
Stratigraphic hiatuses (disconformities) occur between Middle Silurian
and Pleistocene, and between the Lower Silurian and Upper Ordovician
age rocks. Local lensing may totally remove some rock units
(Waukesha Formation). See Exhibit II-1.
The lowering of sea level which produced the disconformity
at the end of the Ordovician period resulted in local valleys cut as
much as 150 feet deep in the underlying mudstones. With the re-
advance of the sea, these valleys were subsequently filled with
the shaley dolomite of the Edgewood Formation, which was not
D-l
-------
System
QUATERNARY
SILURIAN
ORDOVICIAN
Series
( 1
/ Pleistocene S
(
Niogaron
\
Alexandrian
Cincmnatian \
Formation/Member
WADS WORTH
MEMBER
WEDRON
FORMATION
h-^ " *,.«-*>. ,.r ,-r * - *-
RACINE
(0 -300')
(WAUKESHA)
(0-20')
JOLIET
(4O-7O'J
Romeo
Markgraf
Brandon
Bridge
KANKAKEE
(20-50')
(EDGE
(0-
^-*-*^~^~^-
|
£ BRA
o SH
1 (0-
1
t>
0
'WOOD)
100')
MFDA
(0-15')
INARD
ALE
100')
Base
Column
%
/
y4
/
"/"i.
/
/
I
?:<
tri
/
^
/'
^
/
/,
f:
/
::-)/
/
/
i^.
/
/
1
1
1
/
1
/
\
^
/
h
rJ
I] \
1
I
L
1
/
j
1s
y
\
/
/
/ /
/
\ /
/X /
/
^
__
^
'not desert
~!
Description
Till and outwash deposits. Clayey silt with
sand lenses. (Gravel lenses possible but not
probable - described in soils report. )
Bouldery till, clayey silt with sand lenses,
gravel, boulders common near base and at
unconformity. (Described in soils report. )
Gray- brown, argillaceous, fine groined,
thin bedded dolomite containing reefs
of pure, gray, massive, vuggy, dolomite.
Gray, fine grained, silly dolomite.
(Generally absent m northern area )
Light gray, pure, porous dolomite.
Light gray, si I ty, very fine groined dolomite
Red or greenish gray dolomite and
mterbedded shale.
Light brown, fine groined dolomite with
prominent wavy clay partings.
Brown to gray sha/ey dohmite.
(Cherty near top. Not recognized in
project area J
"^^^"/Z^-jT^ ^""^^^T ~i^7~^77C~* J""~~< g~^^~" ^~"~ ' '
Oolite and red shale. (Generally absent)
Green to brown fossiliferous mudstone
tied
STRATIGRAPHIC SEQUENCE
D-2
-------
recognized in any of the rock cores recovered during the explorations
reported herein, but which may exist in local areas of the project.
The stratigraphic sequence used in this report has been
developed from rock cores taken along the project alignment.
No surface rock exposures are available for study. The rock units
used follow as closely as possible formational units as described in
the literature (Willman, 1971 and 1973), but vary somewhat in the
designation of formational member units as the contacts between
member units are gradational and thus subject to personal judgment.
Bedrock Surface
The bedrock surface is covered by glacial till throughout
the project area; the bedrock contours shown in Exhibit II-2 are based
totally on interpretation of boring data and are generalized. The
D-3
-------
:*W»:
H*"*:*!:!
EXHIBIT 11-2
NOTE I. ELEVATIONS IN FEET AND
BASED ON C.C.D (CHICAGO
CITY DATUM )
2 FAULTS REPORTED BY VIBROSEIS
SURVEY HARZA ENGR. CO.
CONTOURS ON TOP OF ROCK
AND BEDROCK GEOLOGY
D-4
-------
bedrock relief in the project area is over 60 feet.
The rock units at the till,/rock contact are the Niaguran
age dolomites of the Racine and Joliet Formations. The top of
rock surface is usually broken and open for five to ten feet and
occasionally carries significant quantities of water.
Stratigraphy
A detailed discussion of the stratigraphy of the study
area can be found in the Foundation Science Report, A Geotechnical
Report on the Upper Des Plaines Tunnel and Reservoir Plan, pre-
pared for De Leuw, Gather & Company.
Structure
The geologic structure described in this report is based
solely on interpretation of boring data. No exposures of bedrock
are available for study in the project area. Therefore, the
situation presented in maps and sections must be used in its
broad diagrammatic sense only.
Faults. A number of faults of ten to 30 feet vertical offset
are postulated. The faults are interpretive and have not been
physically observed, but they do further explain stratigraphic
facts developed by the boring program. None of the borings
actually intersected a major fault zone. In many cases, strati-
D-5
-------
graphic offsets of a single fault are probable the result of more
than one fault of smaller proportion stair-stepped to produce the
total offset.
With borings spacer! a I 1,000-foot centers, as m (his
program, il is also possible for fault blocks of greater or lesser
proportion than those shown !o exist between borings and not be
represented on geologic maps and sections. The general structural
trend for faults is expected to be NE-SW and NNW-SSE. The actual
fault trends indicated on the accompanying map are interpreted from
apparent bedrock drainage displacements and may or may not in
fact represent actual conditions.
Three angle borings were drilled to try to sample a fault
zone. No significant amounts of faulted or gouged rock could be
identified in any of these holes although a few core Loss zones
occurred which may represent small shear zones. However, the
rock on either side of the core loss zones does not appear bisected
as might be expected if a major fault zone were nearby.
The Des Plaines Disturbance. The project is immediately
west of a geologic anomaly known.as the Des Plaines Disturbance.
This disturbance is a five- and one-half-mile-diameter area having
a very complex system of high-angle faults. Fault displacements
D-6
-------
along the edges of the disturbance range from ^0 to 300 feet, and
in the interior reach 900 feet. Thus, faulting may he aptly described
as severe, and the fault system may be expected to extend some
considerable distance away from the boundary of the disturbance.
Shear zones associated with the fault system would cause support
problems and would yield high volumes of water. Because of the
anticipated areal faulting, water infiltration problems would prob-
ably be severe. Also, because of the offsets across individual
faults, it would be difficult to avoid the contacts betwe.-n rock
meiiV rrs, again adding to water inflow and support p ro!>] ruus.
Jointintj. Joints, although not numerous in the rock, have
a significant influence on its permeability and local tunnel stability.
The open joints act as a conduit to carry groundwater from the
overlying glacial till to the bedding planes in the upper rock units
(Racine and Joliet Formations). The numbers of the open joints
are relative indicators of the amount of groundwater to be
expected in a given rock. Those data clearly demons! rau- Hie
more open and permeable natures of the Racmc and Upper .loliel
(Romeo) Formations.
D-7
-------
Earthquakes. In the past, damage from earthquakes has
not been extensive or severe in Northern Illinois. Past disturbances
have ranged in intensity up to VII on the Mercalli scale, but a VII
intensity was recorded only once in history. Presently, the study
area is in Seismic Risk Zone 1, an area predicted to experience
only minor damage from earthquakes that have the epicenters
outside the state. Intensities of the disturbances are predicted
to range from V to VI on the Mercalli scale. A V intensity distur-
bance; is felt by nearly everyone and breaks glassware and windows.
A VI intensity disturbance is felt by everyone; objects are upset;
and chimney and plaster damage occurs.
SOILS AND SURFICIAL GEOLOGY
The basic drainage patterns, landforms and soil parent
materials are related to the Wisconsin glaciation. Glacial deposits
may approach depths of 60 feet in this area. The texlural composi-
tion of these morainal till deposits range from clay to clayey silt,
with varying amounts of sand, gravel and boulders. At the earth
tunnel depth, the soils range from clayey silts to silty clays, with
occasional sand and gravel. In this area, the Tinley Moraine
directly overlies the Valparaiso Moraine. The Tiriley Moraine,
predominately .1 silty clay, m
-------
APPENDIX E
REGIONAL WATER RESOURCES AND NEEDS
SECTION A
Sources of Water Supply
2.01 GENERAL At the present time, Lake Michigan and
groundwater are the sources for public water supply in north-
eastern Illinois. Groundwater is developed from four aquifer sys-
tems: 1) sand and gravel deposits in the glacial drift; 2) shallow
dolomite formations; 3) the Cambrian-Ordovician aquifer; and 4)
the Mt. Simon aquifer. For purposes of this report, the sand and
gravel deposits and the dolomite formations are collectively re-
ferred to as the shallow aquifers, while the Cambrian-Ordovician
aquifer is referred to as the deep sandstone aquifer. The Mt.
Simon aquifer is considered separately and discussed to a lesser
degree because it is virtually unused at present. While there are
several surface streams flowing through the region, only the Kan-
kakee River has been seriously considered as a source of public
water supply.
2.02 LAKE MICHIGAN Lake Michigan is the most extensively
used water source. It provided 1,105 million gallons per day
(MGD) for public water supply in 1970, or about 85 percent of
the region's total public water supply needs. (1) From a purely
physical standpoint, the Lake offers an almost limitless amount of
water that can be readily treated to acceptable drinking water
quality. It should be noted that no water flows naturally from
the Lake to the region. That which is withdrawn for water supply
and other purposes constitutes a diversion. Currently, this diver-
sion is limited to 3,200 cubic feet per second (cfs), or about 2,OHO
MOD, as a result of a 1967 U.S. Supreme Court Decision.
The City of Chicago is the largest user of Lake Michigan water,
withdrawing amounts to meet its own needs as well as those of
72 suburban communities in Cook County which purchase water
under contract. Additional water is withdrawn by fourteen other
public water supply systems located along the Lake Michigan
shoreline in Cook and Lake Counties; service by those systems
is usually limited to one or two communities. Given the expected
future development of the region, coupled with decreased ground-
water availability in certain areas, the Lake will be more heavily
relied upon for public water supply in the future.
2.03 SHALLOW AQUIFERS The shallow aquifer system in
northeastern Illinois is comprised of unconsolidated sand and
gravel deposits of the glacial drift and dolomite formations, mainly
of Silurian age. Although these aquifers uu- hytlraulically intci-
connected, their characteristics are sufficiently different to warrant
separate discussion.
a. Sand and Gravel Aquifers The sand and gravel aquifers ran-
domly underlie approximately 50 percent of the region at depths
ranging from near the land suifare in certain areas to more than
400 feet in others. (Figure 2-1 is a cross-sectional illustration of
(l):flef. l.pg. 3
Figure 2-1
The Groundwater Aquifers of
Northeastern Illinois
GEOLOGIC
HYDROLOGIC
THICKNESS
(FEET!
CRYSTALLINE HOCK
-------
the entire regional aquifer system.) Extensive surficial sand and
gravel deposits are found in parts of DuPage, Kane, Lake,
McIIenry and Will counties, while deeply buried deposits are
found widely scattered throughout Kane and McHenry counties,
western Lake County, northeastern Cook and DuPage counties
and central Will County. Generally, the greatest chance for suc-
cessful well penetration of a productive water yielding sand and
gravel formation is within subsurface valleys cut into the bedrock
by preglacial and glacial geological processes.
Because of their irregular occurrence, the sand and gravel
aquifers are more difficult to locate than the deeper, more exten-
sive sandstone aquifers. They are also more difficult to develop
for large water supply systems since they are more directly affected
by the vagaries of rainfall and drought. On the other hand,
the glacial drift aquifers are generally more rapidly recharged,
are more permeable than the deep aquifers, and involve lower
drilling costs. Locally they provide good sources of supply to
municipalities and private individual users, with some wells yield-
ing in excess of 1,000 gallons per minute (gpm). In 1970, ap-
proximately 31.4 MGD were pumped from the sand and gravel
aquifers in the six-county region. This amounted to approximately
Figure 2-2 Area of High Yield from the
Shallow Dolomite Aquifer
12 percent of the estimated total groundwater pumpage in that
year, which was 261.2 MGD.(2)
The hardness content of raw water is extremely variable but
usually ranges between 100 parts per million (ppm) and 450 ppm.
The iron content which can affect the taste, appearance and use
of water averages about 2 ppm and is higher than that of the
deep aquifers and Lake Michigan. Water temperatures average
about 52 degrees, which is considered to be cool and refreshing.
b. Dolomite Aquifer Underlying much of the region at depths
varying from ground surface to 450 feet deep is the shallow dolo-
mite aquifer. In this aquifer groundwater is found in joints and
fractures, and it moves through an interconnected network of
these openings. Since these water-bearing cavities are unevenly
distributed both horizontally and vertically, the yields of wells
drilled into the dolomite vary greatly from place to place. Suc-
cessful development for water supply depends upon a well inter-
secting a large, water-filled fracture which is capable of sustaining
heavy pnmpaije over time. Some .veils drilled into dolomite yield
in excess of 1,000 gpm, while others result in very low yields.
Figure 2-2 shows the general area of highest yields from this
formation.
The dolomite aquifer is an extensively used source of water
supply for many municipalities, particularly in DuPage County
and southern and northwestern Cook County. In 1970, total
pumpage from the dolomite was estimated at 90.7 MGD, which
was approximately 35 percent of the region's groundwater with-
drawal.(3) In several areas the aquifer is being pumped in excess
of recharge, and there have been significant declines in water
levels and well yields.
c. Estimates of Potential Yield Potential yield is defined as the
maximum amount of water that can be developed from a reason-
able number of wells and well fields without creating critical water
levels or exceeding the rate of groundwater recharge. The Illinois
State Water Survey has estimated the potential yield of the shal-
low aquifers (sand and gravel and dolomite combined) at 507
MGD, assuming they are fully developed in the six-county
area.(4) According to the total shallow aquifer pumpage figures
noted above, only 122.1 MGD were withdrawn in 1970. Thus, on
a regionwide basis, the shallow aquifers are currently producing
only about 25 percent of their potential yield, and there is greater
opportunity for increased development of them for future water
supply.
2.04 CAMBRIAN-ORDOVICIAN AQUIFER The Cambrian-
Ordovician (or deep sandstone aquifer) is regarded as the best
bedrock aquifer in Illinois because of its consistently high yield.
It extends continuously throughout the region and is uniformly
productive. This aquifer is actually a vertical series of water-
bearing rock fonViations, of which the Glenwood-St. Peter and
Ironton-Galesville sandstones ure the principal producers. The
latter is considered to be the most productive and supplies over
50 percent of the aquifer's total yield. Because this aquifer has a
regional southeasterly dip of about 10 feet per mile, the top of
the Ironton-Galesville sandstone lies about 800 feet below the land
surface in the northwest corner of the region and increases to a
depth of about 1,800 feet in the southeastern part. The saturated
thickness of this aquifer varies from approximately 100 feet to
about 275 feet, while the avetage collective thickness of the geo-
logic formations comprising the aquifer is about 1,000 feet. It is
significant to note that while some recharge of the deep sandstone
l by
i Howion Eng«w*r*
(2):Ref. 2
(3): Ref. 2
(4): Ref. 3
E-2
-------
occurs in western Kane and McHenry counties, most takes place
in areas outside of the metropolitan region, including Kendall,
Boone and DeKalb counties of Illinois, and in certain areas of
southeastern Wisconsin. It is important that future urbanization
and land use in those areas not have an adverse impact on
recharge.
The Cambrian-Ordovician aquifer is the most heavily pumped
aquifer in the region; it furnished approximately 53 percent of
the total groundwater used in 1970. Since 1958, withdrawals from
this aquifer have exceeded the practical sustained yield, which is
defined as the maximum amount of water which can be continu-
ously withdrawn from existing pumping centers without eventually
dfwatcring the most productive unit (i.e., the Ironton-Galesville
stundstone). The practical sustained yield of the Cambrian-
Ordovician aquifer has been estimated at only 46 MGD. Pumpage
data for 1970 indicates that actual withdrawals approximated 139
MGD, or about three times the estimated sustained yield.(5) This
withdtawal of water at rates in excess of natural recharge (termed
"mining") has been reflected by a progressive decline in water
levels, increased pumping lifts and increases in pumping costs.
During the period 1966-1971, annual water level declines in wells
in the Cambrian-Ordovician aquifer averaged nine feet.
Table 2-1 lists the increases in pumpage from the deep sand-
stone aquifer during the period 1966-1971.
TABLE 2-1: PUMPAGE FROM DEEP WELLS IN NORTHEASTERN
ILLINOIS, 1966-1871 (IN MGD) (6)
Public
Supplies
County
Cook
DuPage
Karm
Lake
McHenry
Will
Total Region
1966
31
11
23
2
2
12
81
1971
42
16
26
5
2
14
105
industrial
Supplies
1966
24
1
3
1
1
16
46
1971
17
1
2
2
1
14
37
Total
1966
55
12
26
3
3
28
127
1971
59
17
28
7
3
28
142
While industrial pumpage declined over the five-year period, total
pumpage actually increased 15 MGD as a result of greater with-
drawals for public supply. Particularly noticeable are the increases
in public pumpage in Cook and DuPage counties.
Despite the problem of overpumpage, the Cambrian-Ordovician
aquifer will continue to be an important source of supply. Water
in this system is naturally free of bacterial pollution. The hardness
content is from 200 to 250 ppm in the northwest part of the region,
and increases toward the east as the aquifer increases in depth.
The iron content of the water is usually less than 0.4 ppm. Tem-
peratures range from 54 to about 62 degrees and increase with
depth. The Cambrian-Ordovician aquifer is generally well suited
for large, municipal water systems; yields in excess of 1,000 gpm
have been recorded. Mining of this aquifer cannot be continued in-
definitely. Eventual provision must be made for transfer to an
alternative or supplemental source in areas where water levels and
well yields are declining.
2.05 MT. SIMON AQUIFER The Mt. Simon aquifer underlies
the Cumbrian-Ordovician system and is the deepest in the region.
The top of this aquifer ranges from 1,400 to 1,600 feet below the
ground surface in the northwest, and from 2,200 to 2,400 feet in
the southeast. Its average thickness is approximately 1,600 feet,
with the materials consisting primarily of fine to coarse grained
sandstone. The cleaner parts of the sandstone yield moderate quan-
tities of water, although the aquifer's potential is limited by a
number of factors. The most significant limitation i, ' ..nkish watt
beginning at depths below 1,300 feet mean sea le\u, necessitating
costly treatment prior to use. The aquifer also is not consistently
permeable. Furthermore, deep and expensive wells are involved,
The practical sustained yield of the Mt. Simon aquifer has been
estimated at 14 MGD, although development of this -ource ha
been virtually nonexistent to date. In 1973, the Illmoi" State Watei
Survey completed a feasibility study of developing a-n. desalting
water from the Mt. Simon aquifer. Reverse osmosis ,MH\ freezin"
processes were considered feasible for 1 MGD cap.' .ihnon;
plants, while distillation was considered feasible fc>< . ,n i > pl:,i ts
Costs (including wells, transmission lines, desalting (,i> i ';<-s ai-
brine disposal) ranged from $1.33/1,000 gallons fo< \ \!< .
reverse osmosis plant to $1.85/1,000 gallons for a 5 M' 1, ,<
tion plant.
2.06 SURFACE WATER RESOURCES Unlike man .lur Ian;.
metropolitan areas, no inland lakes, rivers or streams are presei
used for public water supply in northeastern Illinois. There >
however, substantial industrial use of water from the S.imtary ,n,i'
Ship Canal, the Calumet River, the Des Plaines River and, to ,1
lesser extent, the Fox River.
a. Limitations There are several factors which have mitigated
against the use of surface watercourses. Certainly one reason (at
least until recently) has been the readily available supply of
groundwater which could be developed at low cost. But the major
deterrent has been the general poor quality of the region's surface-
waters, a problem which necessitates thorough, expensive treat-
ment. While water treatment technology has advanced to the point
where virtually any water can be made potable, the cost of such
treatment may be excessive, especially when compared with tin-
cost of developing alternative sources. Waterways such as the Des
Plaines River have been discounted as viable sources of municipal
water supply because of their lack of dependable flow, high con-
centrations of bacterial and viral organisms, high solids and heavy
metals content, and undesirable tastes and odors.
Nevertheless, the suitability of these waters should be periodi-
cally reevaluated in light of changing needs and conditions. As
improved methods of wastewater treatment are employed and as
nonpoint sources of pollution are reduced, surface waterways may
become economically feasible and attractive water sources. In the
interim, greater attention could be given to increased use of these
waters for non-domestic purposes whenever possible in order to
alleviate competitive pressures on water resources which are suit-
able for public supply.
b. Kankakee River It should be noted that the Kankakee River
is an exception to the foregoing discussion and does offer potential
for development as municipal supply. The river's raw water quality
is reasonably good, and its large flow volume would eliminate the
need to construct expensive storage reservoirs. In addition, it is
proximately located to the Joliet area where there is concern for
the long-term availability of groundwater.
c. Fox River At the present time it is not advisable to use the
Fox River for domestic purposes since a high percentage of its
flow consists of wastewater treatment plant effluent which presents
a risk of viral or chemical contamination. (7) However, the Fox
River may offer some potential for future use as a public water
supply. Indeed, state water quality standards have designated the
river for "domestic and food processing water supply," and pollu-
(5): Ref. 2
(6): Ref. 4, pg. 8
(7): Ref. 5
E-3
-------
tion abatement efforts necessary to achieve that standard are un-
derway. After the desired level of water quality has been attained,
the river might be used for this purpose. One possible approach
would be to reduce deep well pumpage in the Fox Valley area to
the rate which can be sustained without mining. Demands which
could not be satisfied by groundwater under this condition could
be compensated for through withdrawals from the river. During
seasonal low streamflovvs, well pumpage could be increased beyond
sustained yield on a short-term basis until normal flows are
resumed.
') percent) wre taken from the deep sandstone aquifer, 36.4
MOD (36 nru-ent) from the dolviuti-. and 3.7 MOD (4 percent)
from the sh.iilow sand and gravrl
Deep sandstone pumpage in Cook Count j is more than twice
'hat in any other northeastern Illinois county. Water well levels
have declined in response to heavy drawdowns, particularly in the
northwest and southern portions. There is also significant pumpage
from the shallow aquifers, especially in the southern sector.
Chicago HeighK, and to a lesser extent LaGrange, have been
identified as ,ue;is where pumpage has exceeded recharge. County-
le, the i ' >;.!'<>u 01 allow aquifer potential yield is 98 MGD.
2.09 DU PAGE COUNTY DuPage County is supplied exclu-
sively with groundwater, and pumpage in 1970 averaged 51.7
MGD. The dolomite accounted for 33.9 MGD of the total with-
drawal (66 percent), while the deep sandstone yielded 15.5 MGD
(30 percent) and the sand and gravel aiiiifers 2.3 MGD (4
percent).
There is considerable concern for the long-term adequacy of
groundwater supplies in DuPage County. The potential yield of
the sand and gravel and dolomite aquifers is estimated at 42
MGD and by 1972, pumpage from these aquifers had increased to
39.7 MGD. In some areas (most notabiy in the vicinities of
Hinsdale, Clarendon Hills, Addison, Downers Grove, Wheaton
and Glen Ellyn) the dolomite is already being pumped in excess
of recharge, and there has been permanent lowering of the water
table and reductions in well yields. In an effort to compensate for
these declines, increased numbers of deep sandstone wells have
been drilled. Extensive mining is being practiced, and water levels
in the deep wells have been declining steadily for several years.
2.10 KANE COUNTY Kane County is supplied primarily with
groundwater, although there is some minor industiial use of the
Fox River. The western two-thirds of the < ounty is largely rural,
and no particular water supply problems are being experienced.
However, in the more urbanized Fox River Valley urea, the
Cambrian-Ordov ician aquifer i;> heavily used, and steady water
level declines have been observed, particularly in Aurora and
Elgin.
The importance of the deep sandstone aquifer is illustrated by
the fact that it provided 27.9 MGD (or 74 percent) of the 37.5
MGD total pumpage m 1970. The sand ami gravel and shallow
dolomite aquifers produced 6.2 MGD (17 peicent) and 34 MGD
(9 percent) respective^ Theii potential yield is estimated i«s 31
MGD, which is the lowest of the six counties.
2.11 LAKE COUNTY Lake Michigan is the primary source of
supply in eastern Lake County, while groundwater is used in the
central and western portions. In ter ns ot total groundwater pump-
age, development of the three aquifer systems has been ap-
proximately equal. According to 1970 pumpago figures, with-
drawals amounted to approximately 19 MGD. The sam! and giiivel
aquifers produced 69 MGD (36 peu-ent) of the total, followed
by 6.1 MGD (32 percent) from the dolomite and 6.0 MGD (32
percent) from the deep sandstone.
Water level declines in the deep wells are being cxpei wnced
in certain areas (primaiily Libertyville and Mundelein), although
this situation is not as severe as that in Cook and DuPage
counties. There appear to be considerable opportunities for greater
development of the '-hallow aquifers, where potential yield is esti-
mated at 51 MOD.
2.12 MC HENRY COUNTY Of the six counties, McHcnry is in
the most favorable position with respect to water supply The sand
and gravel aquifers are by fur the predorniniiiit .source and their
use is increasing. They supplied 9.4 MGD (or 63 petccnt) of the
county's 15 MGD total pumpuge in 1970. R\ \va\ of contrast, the
deep sandstone produced 3.0 MGD (20 peicent) and the dolomite
produced 2.6 MGD (17 percent).
It is significant that the combined potential yield of the shallow
aquifers is estimated at 96 MGD. Thus, while the shallow aquifers
provided 12 MGD (or 80 percent) of McHenry County's total 1970
groundwater demand, this still amounted to only about 13 percent
of the total quantity potentially available to the area from the
shallow system.
E-4
-------
APPENDIX F
raising Lakes Michigan and Huron by 4.4 inches, excluding the
effects of the Illinois diversion. The effect of the present Illinois
diversion (exclusive of the diversion into Lake Superior) is to
lower Lakes Michigan and Huron 2.7 inches The net effect of
these m-and-out diversions is to raise the levels of Lake Michigan
and Lake Huron by 1.7 inches. To put this in perspective, artificial
diversion into the Great Lakes presently exceeds diversion out of
the Lakes by approximately 1,800 cfs. It therefore would appear
that diversion by Illinois could be increased without having any
critical effect on the Great Lakes Basin as a whole. Indeed, such
.111 increase would ullow n better inflow-oiitllow balance to be
achieved.
SECTION C
Groundwater Mining
8.12 GENERAL There are two basic approaches to groundwater
development. The first regards aquifers only as systems through
which water moves, and favors limiting well withdrawals to the
practical sustained yield. The second approach, mining, favors con-
tinued withdrawal of water from the aquifers at a rate which
exceed, that of rechaige At the present time, approximately 96
MCD ;,'f UK- 1)2 MGD pumped from the deep sandstone aquifer
in tins icgion arc mined.
fc.l.'i ADVANTAGES AND DISADVANTAGES Mining is a de-
but.ihlc ISMH-. The most common argument against the practice
l/eneialiy li.\s been *h;it since it removes water held in storage, it
deprives future generations of the light to obtain adequate water
at i<",v i ost Tiie extension of this icasoning is that present punipage
illicit I-] be icduced to sustained yield, with any deficiencies to be
made up thioiigli the development of alternative supplies, including
u'uiote suif.iee souices In tins way, water held in aquifer storage
uuiild he kept iii pfiiiianent tuist for future use. The counter
urgMiiifnt in favor of mining is that the water in storage is of no
value' unless it is used In nddition, mining allows large capital
investments in smtate water supply projects to be deferred to a
later date. In the jiteiim, changing technologies and alterations in
watei use patterns conceivably could reduce the need for importing
large quantities of water.
One of the cential objectives of water management is to provide
adequate service with the maximum net benefit to all. Clearly, if
the same benefits can be deuved from any of several alternatives,
t!n> least cost alternative will result in the maximum net benefit.
Since the cost of mining water is usually less than the cost of
obtaining water from an outside source, it follows that mining
may need to be conducted until it is no longer economically fea-
sible, at winch time the next "lower cost" source would be de-
veloped.
There are a number of other reasons why mining of the deep
sandstone aquifer might be continued on a managed basis in north-
eastern Illinois First, if mining were not practiced and with-
drawals were limited to the rate of recharge, a number of
townships m the region would become deficient in groundwater
by 1980 Given existing legal limitations on diversion of Lake
walei. these deficiencies could not easily be satisfied by importa-
tion froi.i that source. Furthermore, considering the existing
investment in wells and pumping facilities, coupled with the large
amount of water held m aquifer storage, it may be expedient to
continue or accelerate mining, at least on a short-term basis. It
should also be noted that the dewatermg of the aquifci as a result
of mining probably would not cause serious damage to the
aquifer's water storage or transmitting properties. Indeed, if after
a period of mining, pumpage were reduced to sustained yield,
water levels would rise and the capacity of the aquifer to transmit
water would eventually return to its original state.
Water Conservation, Recharge, and Recycling
8.14 GENERAL One means of helping to avert water shortages
is to institute water conservation and/or reuse and recycling tech-
niques. Conservation measures employ technical, economic, educa-
tional or legal tools to control water usage in such a way as to
balance it with supply Recycling seeks to maximize the use
potential of any given quantity ol water. The primary objective
of both of these approaches is to manage existing sources more
efficiently and effectively as an alternative to developing new
sources.
8.15 WATER CONSERVATION TECH'.I'. j£S A detailed
discussion of water conseivation (particular) '>mestic conserva-
tion techniques) is contained in Appendix E T!i which follows
is primarily concerned with water metering ana leakage control
with brief attention given to reduction of in-house \v iter waste
a. Metering Metering water consumption is one nethod of en-
couraging thrift and normalizing water demand m a community.
Metering allows consumers to be charged according to the amount
of water they use, thus providing an economic incentive to
minimize waste. For example, greater use of meters has been cited
as a contributing factor to the reduction in per capita consumption
in the City of Chicago, where average water use decreased from
302 gpcpd in 1930 to 249 gpcpd in 1972.
Metering is regarded as one of the most fundamental precept-,
of modern water management. Yet. .» number of public vatci
systems in the region do not meter consumption and prefei U.
charge a flat rate for water provided regardless of the amount u -:3
With a flat rate sysloiu in operation, theie is virtually no eco-
nomic incentive for consumers to practice water conservation
It must be iccognized that the cost of purchasing, instullir,1'
maintaining and reading water meters is substantial Thus, it m
not be economical to meter all water users that arc presently
unmetcred, particularly in light of the relatively low rates chaiged
for water in most communities. However, as water become', a
mou: valuable resource in the future, greater metering (at U as!
of new and large users) will probably be practiced.
b. Control of Leaks Leakage from water distribution systems
can create a substantial demand on water supplies without pro
viding any corresponding benefits Excessive leakage reduces the
amount of water available for domestic purposes and increases
overall costs. A number of factors influence leaks, including age
of the system; maten'als used m construction; physical and chem-
ical properties of the soil; properties of the water, pressures in-
volved; and the degree of proper maintenance.
While no system is absolutely tight and some leakage will
inevitably occur, leaks should be reduced to the greatest practical
degree. In the construction of new distribution facilities or in the
replacement or addition to older facilities, leakage control can be
achieved through proper sealing of joints and testing for tightness
Control in existing systems can be achieved through an ongoini'
detection and correction piogram. However, the savings deuved
from such a program must be balanced against the costs of its
operation. Total elimination is seldom justifiable economically, bin
it can proceed to the point where the cost of salvageable water Sost
equals the cost of a repair program. Any additional rehabilitation
beyond this point would not be economical since the cost of repair
would exceed the incremental benefits derived from the water
savings.
The appropriate magnitude of a leakage detection and repan
program is thus dependent upon a number of factors, the most
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important of which art' the rate of loss of salvageable water
within the system, the cost of supplying water; and the cost of
system maintenance and repair. Individual communities contem-
plating a leakage control program should evaluate their particular
systems in light of these conditions to determine the extent of
corrective' ailion warranted Those having serious leakage prob-
le-rm nuv Ix-nefit coiisider.ibly from increased water savings,
especially if water costs are high or supply is inadequate. Con-
veisely, communities that ha\e relatively minor leakage problems,
low water costs ancl abundant supplies probably need not under-
take extensive coutiol programs.
c. Water Conservation in the Home Several steps can be taken
to reduce water consumption uiuKoi waste in and around the
luiine. Maintenance am! lepair of leaky plumbing fixtures can
s.i\e huge quantities of water over time which otherwise would be
lost Use oi water conserving devices such as shallow trap toilets,
washing machine "suds savers" and restricted How showerheads
can also reduce in-house witer consumption. Substantial reduc-
tions can also lie ellettcei by taking care that lawns arc not over-
wateied ami that too much water is not used for such activities
as washing automobiles Conscious efforts to eliminate waste not
only < onsen c water but also result in economic savings in the
form of reduced watei bills.
8.16 ARTIFICIAL RECHARGE Intensive development of
Hunmdw.itei lias ricafed considerable interest in the possibility of
.ntiliciaUy ice-barging the aquifers Replenishment of water in
,'reas of concentiated punipage. it feasible, would reduce the rate
ft \\atei level decline and improve the yield capacity of wells.
( Vusequently, the ines of existing wells could be prolonged and
the aquifer could continue to provide a dependable water supply.
n. Sources of Recharge Water The most readily available source
ot watei for uitificia! recharge i,s the seasonal high flow in surface
>h earns. The diversion of high flov,s from stream channels foi
aitificial recharge would also make available additional storage
space in these channels for the temporary stoiagc of flood peaks.
Sophisticated stormwater diainage systems piovide efficient means
foi the collection and tempoiaiy detention in basins of water that
also cini be nstd for aitificial icch.irge of the shallow aquifers. If
the1 highy polluted initial Hush from urban areas is bypassed, the
rein.lining stonnwater, if treated, may be suitable for artificial re-
cli.iryc However, the feasibility of this technique' needs to be
moie thoioughly investigated. Other possible .sources include cool-
ing water, certain industrial waste-waters, and conceivably, treated
domestic wastewater.
b. Methods The three principal methods of direct artificial re-
charge are water spreading, seepage pits and injection wells
Induced infiltration from streams caused by pumpage from nearby
wells is an mcliiect method of artificial recharge. Whatever the
method, artificial recharge icquije.s agencies and facilities to:
obtain, treat (if necessary) and transport the; water to the recharge
aiea, mfiltiate or inject the \vatei, and provide for the disposal of
any excess water. The development of the area affects the capital
cents of the- project. High land costs in the urbanized parts of
the region faven the use of the pit and injection well methods
which icquire less land. Spreading basin methods require more
land and would more likely be used in rural areas. Economics will
slrongK influence the; degree to which artificial it-charge operations
ait initialed in the* future.
e. Potential Recharge Areas The Illinois State Water Survey has
identified ten areas in northeastern Illinois which would probably
!» suitable for the pit method of artificial recharge. These areas
\vcie selected because, there was a well-defined cone of depression
in the water level suitace of the aqmfei under consideration; there
was a suificial sand and gravel deposit in the area, and there was
a perennial stream in the immediate vicinity to seive as a ..) i
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Figure 8-1 Prime Natural Recharge Areas in Northeastern Illinois
scale in miles
Based on information provided by the
Illinois State Water Survey
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realistic alternative in northeastern Illinois, at least in the immedi-
ate future. It is true that sophisticated methods of waste treatment
are presently available which allow near total reduction in the
biological and chemical contaminants of wastewaters. When thus
purified, the effluent is suitable for industrial or agricultural pur-
poses. However, the cost of such treatment, when coupled with
health concerns and probable aesthetic objections, does not pres-
ently favor the use of recycled wastewater for municipal supply.
During 1973, this Commission reviewed two separate but related
applications for federal funds which involved testing the feasibility
of recycling wastewater effluent for use as potable water supply.
The applicants were the Village of Bensenville and the Hinsdale
Sanitary District, both of which are located in eastern DuPage
County where there is considerable concern for the adequacy of
local groundwater supplies. The basic concept of both these pro-
posed research and development projects involves the incineration
of municipal solid waste to produce heat, which can then be used
to distill treated wastewater plant effluent. Depending upon the
outcome of test results, the distillate could be used to directly
augment present water supplies or to increase local groundwater
recharge. Both projects are presently being reviewed by the
USEPA. Their futures are uncertain at this time due to the paucity
of federal funds for projects of this nature.
SECTION E
Organization and Administration
8.19 FRAGMENTATION Perhaps the most conspicuous short-
coming of the present institutional framework for water supply
is the extensive fragmentation of authority and responsibility.
Several federal, multi-state, state, regional, and county agencies
conduct specialized programs which have significance in water
supply planning and management. At the local operational level,
there are approximately 260 municipalities and numerous special
purpose districts which are empowered to furnish water and en-
gage in related activities. Then, too, there are a number of private
utility companies authorized to provide water, principally in
subdivisions and other unincorporated areas.
At the present time, this Commission is the only governmental
unit conducting a comprehensive water resources management
planning program in the six-county northeastern Illinois region.
On the operational level, the trend continues toward the creation
of more separate and independent systems which deal with prob-
lems on a piecemeal basis. Waterworks have been constructed and
expanded without benefit of areawide planning, coordination or
controls. Slight attention has been paid toward developing a water
supply system for the region as a whole, with the view of pro-
viding for needs beyond the immediate future. Instances of co-
ordinated, interlocal efforts have been few. Indeed, there are cases
in which there has been keen competition between communities for
available water, a situation which has at times interfered with the
optimum development of the resource.
There are, of course, examples of successful intergovernmental
cooperation. The arrangement by which the City of Chicago pro-
vides water to suburban Cook County communities is the most
notable. Some of the lakeshore communities north of Chicago
provide water to neighboring inland municipalities on a similar
though more limited basis. There are also four public water com-
missions or districts which were organized for the purpose of
obtaining and furnishing water to customer municipalities on a
sub-regional scale.
The Great Lakes Basin Commission has noted that although it
may be difficult, more emphasis should be put forth in developing
plans for areawide utilities and cooperate efforts. (15) Problems
such as well interference could be solved by preventing the
proliferation of small water systems while favoring larger utilities
which cross corporate boundaries and which develop the best
available source of water rather than relying heavily on wells in
the immediate area. The GLBC recommends that the preparation
of such plans, before population pressures and increased water use
necessitate independent crash programs, should begin immediately
and be worked out with local, county and regional planning com-
missions. Implementing plans for areawide utilities may require
the creation of additional laws .ind regulations.
The most pressing future water supply need will be that of
providing adequate substitute sources for those areas of the region
where groundwater deficiencies arr expected to occur. Given the
fact that the areas of projected shoitage are jsenerallv located some
distance from Lake Michigan, it is not i<>asil>K. tor individual
municipalities to construct their own independent systems. Some
type of multi-community approach may have to !>t Liken m order
to achieve economies of scale arid to minimize conilicts and in-
efficiencies.
8.20 ORGANIZATIONAL ALTERNATIVES There arc several
alternative organizational structures which might be established for
this purpose, varying both in scope of authority and area of juris-
diction. A number of these possible alternatives are highlighted
below to illustrate the range of management opportunities avail-
ble.
a. Maintain Existing Arrangements This is a continuance of the
status quo in which no major changes in agency structures or pre-
rogatives would be effected. Water supply development and use
decisions would continue to be made at local levels, generally
without regard for broader area needs and problems.
Water supply has traditionally been viewed as a local respon-
sibility, and attempts to drastically alter this approach may not
withstand the test of implementation. Therefore, expansion and
coordination of the water supply programs of existing local units
may be the most politically feasible and realistic method for deal-
ing with water supply problems on a regional scale. The potential
for duplication of effort, waste of funds, arid competition and
conflict would remain.
b. Metropolitan Water Authority At the opposite end of the
institutional spectrum would be the creation of a six-county metro-
politan water authority. If authorized, this agency would assume
primary responsibility for furnishing water on a "wholesale" basis
throughout the region, or for significant portions thereof where
economies of scale might favor such an arrangement. Source
development, treatment, and primary transmission would fall
within its purview. Individual municipalities would retain re-
sponsibility for constructing and operating local distribution and
storage systems.
It would also be possible to expand the role of the water
authority to include other important aspects of water resources
management. This has been done in the Detroit metropolitan
area where a single agency was created to deal with the water
supply, wastewater, and stormwater drainage problems of Detroit
and 88 neighboring municipalities. With respect to water supply
alone, significant cost sailings have been realized as a result of
the metropolitan utility approach.
Such an agency would allow for the systematic expansion and
operation of all public water facilities in the region. It would of
course be necessary to base such functional program on a com-
prehensive plan for the region to ensure orderly and efficient
growth and development. Other issues requiring careful consid-
(15): Ref. 9, pg. 278
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