UNITED STATES
ENVIRONMENTAL PROTECTION AGENCY
REGION 5
WATER DIVISION
230 S. DEARBORN STREET
CHICAGO, ILLINOIS 60604
AUGUST 1977
ENVIRONMENTAL
IMPACT STATEMENT
FINAL
TUNNEL COMPONENT OF THE TUNNEL
AND RESERVOIR PLAN PROPOSED BY THE
METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
Lower Des Plaines Tunnel System
Summary Report
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UNITED STATES
\ ENVIRONMENTAL PROTECTION AGENCY
g REGION V
-^ 230 SOUTH DEARBORN ST.
y
CHICAGO. ILLINOIS 60604
TO ALL INTERESTED AGENCIES, PUBLIC GROUPS, AND CITIZENS:
Enclosed is a copy of the Summary Report of the Final
Environmental Impact Statement (EIS) for the Lower
Des Plaines System of the Metropolitan Sanitary District
of Greater Chicago's T.unnel and Reservoir Plan. Should
you wish to examine the detailed Final EIS, a limited
number of copies are available and may be obtained by
writing to Mr. Kent Fuller, Chief, Planning Branch at
the above address. Requests should be marked for
Attention: EIS Preparation Section. Pursuant to the
regulations promulgated by this Agency (40 CFR 6,
April 14, 1975) no administrative action will be taken
prior to September 25, 1977.
Sincerely yours,
George R. Alexander,
Regional Administrator
Enclosure
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EPA-5-IL-COOK-INT-77
SUMMARY REPORT
FINAL ENVIRONMENTAL IMPACT STATEMENT
TUNNEL COMPONENT OF THE
TUNNEL AND RESERVOIR PLAN
PROPOSED BY THE
METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
LOWER DES PLAINES SYSTEM
Prepared by the
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION V
CHICAGO, ILLINOIS
And
BOOZ, ALLEN AND HAMILTON, INC.
BETHESDA, MARYLAND
APPROVED BY:
GEORGE VR. ALEXANDER^ JR
REGIONAL ADMINISTRATOR
AUGUST 1977
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EXECUTIVE SUMMARY
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FOREWORD
This executive summary supplements the Draft Environ-
mental Impact Statement (EIS) on the Tunnel Component of
TARP, specifically the segments and branches of the Des Plaines
Tunnel system. Copies of the Final EIS may be obtained by
writing the U.S. Environmental Protection Agency, Region V,
Planning Branch, EIS Preparation Section, 230 South Dearborn
Street, Chicago, Illinois 60604; or by telephoning the TARP
project officer at (312) 353-7730.
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ABLE OF CONTENTS
Executive Summary
Page
Number
I. BACKGROUND INFORMATION -iii-
1.1 Legal Basis for the EIS -iv-
1.2 Scope of the EIS -iv-
1.3 Identification of the Applicant -iv-
1.4 Project History -v-
1.5 Objectives of TARP -vii-
II. EXISTING ENVIRONMENTAL SETTING -viii-
2.1 Natural Environment -viii-
2.1.1 Water Resources -viii-
2.1.2 Land Resources -xi-
2.1.3 Atmospheric Resources -xii-
2.1.4 Biological Resources -xii-
2.2 Man-made Environment -xiii-
2.2.1 Socioeconomic -xiii-
2.2.2 Land Use -xiv-
2.2.3 Sensitive Areas -xv-
2.2.4 Financial Resources -xv-
2.2.5 Labor Resources -xvi-
2.2.6 Transportation -xvi-
2.2.7 Major Projects and Programs -xvi-
III. THE PROPOSED ACTION -xvii-
3.1 Alternative Plans -xvii-
3.2 Plan Selection -xviii-
3.3 TARP Tunnel Systems -xix-
3.4 TARP Subsystems -xxi-
3.5 Des Plaines Tunnel Segments and Branches -xxii-
3.6 Cost of Tunnel System and Subsystems -xxii-
3.7 TARP Financing -xxiv-
IV. PRINCIPAL FINDINGS CONCERNING THE EFFECTS OF
THE PROPOSED ACTION -xxix-
V. CONCLUSIONS AND RECOMMENDATIONS -xxxvii-
-ii-
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I. BACKGROUND INFORMATION
This chapter first defines the legal basis and the scope
of the EIS and then describes the authority and program of the
applicant for EPA funding, the MSDGC. Finally, the history
and objectives of the Tunnel and Reservoir Plan (TARP) are
reviewed. This chapter of the executive summary corresponds
to Chapter I of the environmental impact statement (EIS) .
1.1 LEGAL BASIS FOR THE EIS
The U.S. Environmental Protection Agency (EPA) is the
administering agency for a major Federal environmental pro-
gram entitled "Grants for Construction of Treatment Works. "-1-
This program allows the EPA Administrator to provide finan-
cial aid to any state, municipality, intermunicipal agency,
or interstate agency for the construction of publicly owned
water pollution control facilities. The program will en-
courage reduction of point sources of water pollution and
improve national water quality.
The EPA's granting of funds for a water pollution con-
trol facility may require an EIS. Each proposed water pollu-
tion control facility is evaluated on a case-by-case basis
by the appropriate EPA regional office to determine whether
the proposed facility is expected to have significant en-
vironmental effects or be highly controversial. The EPA has
prepared this EIS because it expects the environmental ef-
of the tunnel system to be significant.
This EIS is being issued pursuant to PL 91-90, the
:'r, tional Environmental Policy Act (NEPA) of 1969, and Exe-
•-..tive Order 11514, "Protection and Enhancement of Environ-
:c-;tal Quality" dated March 5, 1970. Both NEPA and Execu-
• .e Order 11514 require that all Federal agencies prepare
•, . -:i statements in connection with their proposals for major
-«?'jivral actions significantly affecting the quality of the
:'.: v^.n environment.
Authorized by Title II, Section 201(g)(1), of the Federal Water
Pollution Control Act Amendments of 1972, Public Law 92-500 (FWPCAA)
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This EIS has been prepared in accordance with the
regulations and guidance set forth in the President's Council
on Environmental Quality (CEQ) Guidelines dated August 1, 1973,
and the EPA's Final Regulations 40 CFR-Part 6, dated April 14,
1975.
1. 2 SCOPE OF THE EIS
The EIS addresses the cumulative effects of constructing
and operating three conveyance tunnel systems which are part
of the total Tunnel and Reservoir Plan (TARP) proposed by
MSDGC. These three tunnel systems are:
Mainstream (59th Street to Addison Street)
Calumet
Lower Des Plaines.
Where appropriate, this statement also assesses the effects
associated specifically with the Lower Des Plaines Tunnel
system route. Two other statements address separately the ef-
fects associated with the Mainstream Tunnel system and the
Calumet Tunnel system. The Mainstream and Calumet statements
have already been developed and issued. These tunnel systems
comprise what is referred to in the statement as "TARP, Phase I,
The subject of these statements is confined to the tun-
nel systems and their associated components because EPA is now
considering whether to grant funds to construct these tunnels
under its water pollution control authority. Other compo-
nents of TARP, including the reservoirs, flood relief tun-
nels, instream aeration, and wastewater treatment plant im-
provements, are either ineligible for EPA funding or are not
now under consideration for construction grants. Therefore,
these other components are not considered to be part of the
proposed action under review. The effects of these other
components on water quality and the likelihood of their being
financed is analyzed in this EIS in order to provide a con-
text for evaluating the significance of the water quality
improvements expected from the three tunnel systems.
1.3 IDENTIFICATION OF THE APPLICANT
The Metropolitan Sanitary District of Greater Chicago
(MSDGC) is the construction grant applicant for the compo-
nent of Tunnel and Reservoir Plan (TARP) addressed by this
EIS. The MSDGC was organized in 1889 under an act to create
sanitary districts to remove obstructions in the Des Plaines
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and Illinois Rivers.1 Under the provisions of the act, the
MSDGC is responsible for providing surface water and sewage
drainage within the District's boundaries, which it does by
constructing necessary facilities, conveyance systems, and
treatment plants. The MSDGC is authorized to treat waste-
water, either totally or partially, from any municipality
within its designated jurisdiction, as well as to own and
operate all wastewater facilities located within the MSDGC
jurisdiction.
The MSDGC service area is approximately 860 square miles.
Approximately 44 percent of this area, or 375 square miles,
is served by MSDGC-owned combined-sewer systems (see Figure 1-1)
in which wastewater or sewage collected in local sewer systems
is conveyed to treatment plants. These systems serve 120
municipalities which have a total population of approximately
5.5 million. The District owns and operates 70.5 miles of
navigable canals, 6 wastewater treatment plants, and approxi-
mately 440 miles of intercepting sewers. The three major
plants (North-Side, West-Southwest, and Calumet) in the MSDGC
service area have a secondary capacity of over 1,750 million
gallons per day (MGD). The remaining plants have a combined
tertiary capacity of over 70 MGD. A water reclamation plant,
the John F. Egan plant, is presently under construction and
will have a capacity of about 30 MGD.
1.4 PROJECT HISTORY
The MSDGC initiated its wastewater facilities planning
study in September 1967, with a ten-year clean-up and flood
control program. The objectives of the program are to solve
the District's flooding problem, protect Lake Michigan from
further pollution, and improve the water quality of rivers
and streams in the Chicago metropolitan area. The Tunnel
and Reservoir Plan (TARP) has evolved from this ten-year
program.
Concerned officials from the State of Illinois, Cook
County, the MSDGC, and the city of Chicago reactivated a
Flood Control Coordinating Committee (FCCC) in November 1970
to investigate the pollution and flooding problems in the
Chicago metropolitan area. The Committee's primary assign-
ment was to develop a viable plan to minimize the area's
Illinois Revised Statutes, Chapter 42, Section 320, approved
May 29, 1889.
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FIGURE 1-1
Metropolitan Sanitary District
of Greater Chicago
Service Area
SERVICE AREA OF MSDGC
COMBINED-SEWER
SERVICE AREA
BOUNDARY
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pollutant discharges and the flooding caused by overflows
of mixed sewage and wastewater. Another priority item in
the plan was elimination of the need to release polluted
river and canal flood waters into Lake Michigan. The Com-
mittee's plan was to address the combined-sewer area within
Cook County, covering 375 square miles. The deliberations
and studies of the FCCC and of a technical advisory commit-
tee which they formed resulted in the selection of TARP as
less costly and more environmentally acceptable than the
other plans they evaluated. The Committee then initiated
additional studies to develop and refine TARP.
1.5 OBJECTIVES OF TARP
A primary objective of TARP is to improve surface water
quality within the planning area. TARP is designed to meet
the standards set forth in the "Water Pollution Regulations
of Illinois."1 These regulatory standards were established
for three surface water-use classifications: (1) General
(primary body contact), (2) Public and Food Processing
(drinking water), and (3) Secondary Body Contact and Indigenous
Aquatic Life. All surface waters in the State of Illinois
have been given a water-use classification by the Illinois
Pollution Control Board (IPCB) and should comply with the ap-
propriate water quality standards. Details of these standards
are presented in Chapter II of this EIS. Other important
objectives of TARP are to:
Preserve the health and well-being of the population
Prevent further pollution of Lake Michigan due to backflow
Utilize treated waste byproducts
Prevent flooding.
The final TARP is a combination of several alternative
plans designed to collect urban runoff during all wet wea-
ther conditions except those storms of a magnitude equal to
the three most severe storms recorded to date by the U.S.
Weather Bureau Service.
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II. EXISTING ENVIRONMENTAL SETTING
To provide a basis for assessing the impacts of a pro-
posed project, an EIS initially describes the existing natural,
social, economic, and cultural setting of the area which
may be affected by a project. This chapter summarizes the
major findings of the EIS with respect to the natural and
man-made environments of the Chicago metropolitan area. This
chapter is divided into two sections which correspond to
Chapters II and III of the EIS text: Natural Environment
and Man-made Environment.
2.1 NATURAL ENVIRONMENT
The existing natural environment of the Chicago area
summarized in this section focuses on those features rele-
vant to impact assessment of the proposed TARP project. This
section is divided into the following categories:
Water Resources
Land Resources
Atmospheric Resources.
2.1.1 Water Resources
The surface water systems of the Chicago area consist
of a network of rivers and canals whose natural flow into
Lake Michigan is controlled by a series of locks. These
surface water systems include the Chicago River, the Sanitary
and Ship Canal, the Calumet River system , and the Des Plaines
River system. Lake Calumet and Lake Michigan also constitute
an important part of the area's surface water resources.
The quality of the surface water systems is affected by
steady-state effluent discharges and by injections or dis-
charges of polluted wastewaters. The polluted wastewater
results from overflows of combined-sewer systems during rain-
fall events of nominal size (approximately 0.1 inches or
greater). The frequency of these rainfall events is approxi-
mately 100 times per year, and the resulting overflows are
discharged directly to the Chicago area's streams and rivers.
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Pollutant concentrations in the streams and rivers presently
exceed water quality standards established by the State of
Illinois Pollution Control Board. Concentration ranges of
various pollutants in the Chicago area's surface systems are
presented in Table II-l. Further details on the water quality
of specific water systems are presented in Section 2.1.1 of
the EIS.
Table II-l
Summary of Pollutant Concentration Ranges
in Chicago's Surface Water Systems
Pollutant
Dissolved oxygen (DO)
Biochemical oxygen
demand iSCO)
Amnor.ia 'as ::)
Suspended solids (SSI
recal col i form
ChLcaqo SLvsr —
Sanitary and
Ship Canal System
1.2 to 7.7 mg/1
Cai-jmet River
System
3.9 to 9.3 .nc.'l
1
5.2 -o 9.2 mc/l
C.8 to 6.2 ng/1
19 to 54 mo/1
•J77 to 12, 700
(counts/ICO .-nil
4.1 to 7.3 mg/1
1.3 to 13 ng/ 3.
12 to 73 nq/1 %
152 tc 738
(counts/100 ml)
i
Des Plair.es
River System
6. 5 to 10 mg/1
5.0 to 6.7 mg/1
3.3 to 1.: HV7/1
29 to 63 ng/1
411 to 8,709
(:our.ts/100 ml)
Applicable Illinois Standards*
Secondary
Contact
5.0 mg/11
4.0 ng/1 ! 19 78) 2
3. j ng/1
4.0 ng/1 tru.-..1
2.0 mg/1 min.
4-2C ng. I4
4.0 nig/1 (winter)
2.5 rcg/1 (summer)
5-25 mg/15
1000/100 ml1
General
Use
6.0 mg/1
5. 0 mg/1 min.'
4-20 T.g/l-)
2:6 mq/1-
5-25 ir.g/15
200/100 ml2
* Effluent discharge standards apply if water quality standard is not designated.
i North Shore Channel Standards
* Chicago River-Sanitary and Ship Canal System and Calunet River system.
General Use Standard applicable ic DCS Plair.es River system.
4 4 ng/1-ilanover, Egan, and C'Hare Sewage Treatment Plants
10 mg/l-WSW and Calumet sewage Treatment Plant
2} ma/1-Lemont Sewage Treatment Plane
5 5mg/l-Hanover, Egar., and C'Hare STP
12mg/l-WSW and Calumet STP
2Sng/l-Lemcnt ST?
Serious public health problems involving contamination
of Chicago's drinking water supply has led to implementation
of regulatory measures to protect Lake Michigan, an important
drinking water resource, from pollution. Locks and gates have
been installed to divert river flows away from Lake Michigan,
allowing eventual drainage into the Illinois River. Lake
Michigan supplies most of the drinking water for the Chicago
area. The withdrawal amount is approximately 1,600 cubic
feet per second (CFS), and the maximum amount that can be
withdrawn from Lake Michigan is 3,200 CFS.l This withdrawal
limit, or allotment, is presently divided into three usage
types: domestic water supply, indirect waterway diversion,
and direct waterway diversion. The diversion usages allow
improved effluent dilution and improved navigation.
Supreme Court Decision.
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In the Chicago metropolitan area, there are two main
aquifer systems: the upper aquifer, which consists of gla-
cial drift and dolomites, and the lower aquifer, which con-
sists of dolomite and sandstone formations. Unconsolidated
Quaternary deposits and Silurian dolomites of the upper aqui-
fer are hydraulically connected and function, in most areas,
as a single water-bearing unit. Clayey deposits in the gla-
cial drift act as confining layers to create artesian condi-
tions in the upper aquifer. The lower aquifer includes dolo-
mite and sandstone formations extending from the base of the
Maquoketa Group to the top of the Eau Claire shales of the
Cambrian system. The average thickness of the upper aqui-
fer and lower aquifer is approximately 400 feet and 1,000
feet, respectively. The sources of recharge for the ground-
water in the upper aquifer are infiltration of precipitation
and influent streams. The lower aquifer is recharged in
parts of McHenry, Kane, and De Kalb Counties where the
Maquoketa Group outcrops, and further west where the Group
has been removed by erosion. With respect to using the
aquifers as a water resource, studies indicate that the
lower aquifer is capable of producing about 25 Million Gal-
lons per Day (MGD) and the upper aquifer is capable of a
potential yield of 108 MGD.
Discharges into the waterways of the Chicago area ori-
ginate from several sources, including: wastewater treat-
ment facilities, industrial plants, and combined-sewer over-
flows. Six wastewater treatment facilities currently dis-
charge treated water to existing waterways. The outfalls
are located adjacent to the facilities. Most of these faci-
lities are in compliance with the BOD and SS effluent
standards (under present permit conditions), and two smaller
plants are within the ammonia-nitrogen standard. With re-
spect to industrial plants, wastewater is conveyed to treat-
ment plants and processed before discharging. The industrial
waste load averages approximately 195 MGD or equivalent to a
population of 4.5 million. Combined-sewer overflows, which occur
about 100 times per average year, inject pollutants in large
amounts into waterways at approximately 640 outfall points in the
Chicago area. During such events, minimum Illinois water quality
standards established for restricted-use waters are not met.
Numerous water resource management programs have been
initiated to address the flooding and/or pollution problems
of the Chicago area. These programs have been or are cur-
rently being conducted either regionally or locally. A few
of these programs include: the Section 208 Areawide Waste
Treatment Management Planning program, the Chicago-South
End of Lake Michigan study (C-SELM), the City of Chicago
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Sewer Construction program, Thornton Quarry Flood Control
project, and the Chicago Metropolitan Area River Basin Plan
(CMARBP).
2.1.2 Land Resources
The Sanitary and Ship Canal and the Calumet-Sag Channel
have significantly altered the natural drainage patterns
which are from west to southwest in the area near Lake Michigan,
Prior to construction of the Canal and Channel, the drain-
age flow was toward Lake Michigan. The flow is presently
toward the Chicago River and the Sanitary and Ship Canal,
which drain into the Illinois Waterway system. The overall
low relief of the MSDGC combined-sewer system area makes it
prone to flooding caused by sewer system backups and/or over-
bank flows. The areas with the highest overbank flooding
potential lie along the North Branch-Chicago River and in
the Calumet River system.
The Chicago area lies on -the broad, gently sloping, north-
westerly-trending Kankakee Arch. This arch, which connects
the Wisconsin Arch to the northwest with the Cincinnati Arch
to the southwest, separates the Michigan Basin from the
Illinois Basin. The northeast sector of the Chicago area
lies on the northeastern side of the Kankakee Arch, while
the southwestern sector of the Chicago area lies on the
southwest flank of the Arch. In the Chicago area, overall,
a number of gentle east-west-trending folds are superimposed
on the area's broad regional geologic structures. Numerous
minor faults and several major faults have been mapped, in-
cluding: the Sandwich fault near Joliet and the Des Plaines
disturbance near the community of Des Plaines. The upper-
most 500 feet of rock layers, particularly the dolomites
and shales between the top of the Racine formation and the
base of the Brainard formation, will be relevant to the pro-
posed construction of the TARP tunnel systems. The surface
layer (glacial deposits) has an average thickness of approxi-
mately 80 feet. Drop shaft and construction shaft installa-
tions will be constructed within this layer.
Based on 175-year historical earthquake records, four
major earthquakes occurred within 100 miles of Chicago with
intensities equal to or greater than MMI VIII (Modified
Mercalli Intensity scale). These earthquakes originated at
Fort Dearborn (Chicago) (1804), near Rockford (1909), near
Aurora (1912), and near Amboy (1972). Within the MSDGC
combined-sewer service area, there are 30 faults with moder-
ate vertical displacement characteristics and 86 minor
faults with small vertical displacement characteristics.
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2.1.3 Atmospheric Resources
Air quality in the Chicago metropolitan area is pres-
ently monitored by the city of Chicago Department of Environ-
mental Control and the Cook County Department of Environ-
mental Control. A total of 61 monitoring stations have been
established in Cook County; 30 of these are located within
the city limits of Chicago. Based on the 1974 Annual Air
Quality Report published by the State of Illinois EPA, am-
bient air quality standards were frequently violated at one
or more stations. The pollutant standards violated include:
sulfur dioxide, particulate matter, carbon monoxide, hydro-
carbons, 'and photochemical oxidants (measured as ozone) .
The existing outdoor noise levels in most areas of
Chicago are caused mainly by street traffic. Other noise
sources include trains, aircraft, and industrial plants in
city areas, and power lawn mowers, power tools, and other
motor-driven equipment in residential areas. Based on a
recent EPA study, typical noise levels for the Chicago area
ranged from 36.3 dBA (decibels-A scale) (night) to 106.2
dBA (day). The day-night level (Ldn) ranged from 59.0 dBA
to 71.2 dBA (overall average).
2.1.4 Biological Resources
Many species of wildlife reside in or migrate to the
forest preserves, parks, and other natural areas in the
Chicago region. Over 200 species of birds have been sited
in these areas and about half of these species are the mi-
gratory and waterfowl type. Common mammals residing in the
preserves include: whitetail deer, eastern cottontail,
opossum, raccoon, gray squirrel, red fox, and woodchuck.
Approximately 28 species of reptile and amphibian can also
be found in the Des Plaines area. A comprehensive list of the
wildlife species is provided in Appendix J of the EIS.
Aquatic life in the rivers and streams of the Lower Des
Plaines watershed is currently limited to pollution-tolerant or
hardy species. Poor water quality conditions in the Cook
County reaches of the Des Plaines River have reduced the
diversity and abundance of aquatic life. The major species
of fish in the watershed include: goldfish, carp, green
sunfish, black bullhead, golden shiner, hybrid sunfish, black
crappie, blunt-nosed minnow, pumpkinseed sunfish, northern
pike, largemouth bass, yellow bullhead, redfin shiner, white
crappie, bluegill and yellow perch.
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The natural vegetation normally found in the natural
areas of the Des Plaines Tunnel project area consists of a
modified form of the beech-maple forest, in the more moist
areas, and oak-hickory forests in the more open areas. The
transitional flora between these two forest types include
maple-basswood and maple-basswood-red oak forest.
In the stretch between the Lake-Cook County line and
Summit, Illinois, the Des Plaines River flows through a highly
urbanized primarily residential watershed. However, most of
the river and adjacent flood plain is owned by the Cook County
Forest Preserve District so that some woodlands and wetlands
have been preserved, and urban development has generally
been kept out of the Des Plaines River flood plain. Thus, the
Des Plaines flood plain is an attractive greenbelt. It is
composed of several types of vegetation including cottonwood,
ash, oak, willow and boxelder.
2.2 MAN-MADE ENVIRONMENT
The various components related to man's activities in
the Chicago area are summarized in this section. These com-
ponents include: Socioeconomic, Land Use, Sensitive Areas,
Financial and Labor Resources, Transportation, and Major
Projects and Programs.
2.2.1 Socioeconomic
The Chicago metropolitan area has experienced growth
and change in its demographic profile similar to other major
cities in the United States. Chicago, the third largest
standard metropolitan statistical area (SMSA) in the United
States, has experienced typical population redistribution
trends within the SMSA. The close-in suburban jurisdic-
tions grew rapidly during the 1950's from a substantial in-
migration of population from the south and an out-migration
of people from the city of Chicago. During the 1960's, the
counties adjacent to Cook County urbanized rapidly. Con-
tinued redevelopment of the City, when combined with smaller
household trends, uncertainties regarding energy availability
and cost, and the increasing cost of suburban new construction,
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should result in a strengthening of the urban centers and a
lessening of the outward population movements. Chicago's
population is expected to stabilize after 1980.
Contract construction income accounts for less than
eight percent of total earnings in the Chicago region. While
average monthly wages for construction employment are high
relative to other industries in the Chicago region, total
earnings from contract construction have ranged from 6.5 to
7.7 percent of total earnings over the period 1950 to 1971.
The construction industry is heavily unionized, and the
current union hourly wage rate averages $11.02. (Refer to
Table III-6 of the EIS).
The Chicago area has traditionally sustained strong
construction activity in the public and private sectors.
Major public redevelopment projects have stimulated private
investment and development, particularly within the city of
Chicago. Construction employment opportunities have thus
attracted and created a large construction labor force. Con-
struction employment in the Chicago SMSA numbered 136,897
people in 1970 or approximately 4.8 percent of the total
employed. Construction employment in the Chicago SMSA ac-
counted for 61 percent of total construction employment in
the State of Illinois. The Chicago area construction work
force is highly flexible and can expand rapidly, given the
demand for construction services.
2.2.2 Land Use
The predominant land use bordering the Des Plaines
tunnel route can be characterized by its residential zoning
in which large portions of land are fully developed. Rock
taken from the tunnel will probably be disposed of at two
sites on Forest Preserve lands as well as at McCook, Stearns,
and Thornton quarries. Sludge will be disposed of at a
number of sites or by a number of programs, including: the
Fulton County project, NuEarth, broker sales, Lawndale
Lagoons, and other landfills.
The land areas bordering the proposed tunnel route are
expected to remain generally the same along the main and
branch segments. Enhanced recreational uses along the
riveredges are envisioned as a land improvement by the
communities in the Des Plaines area.
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2.2.3 Sensitive Areas
There are no known archeological or historically signi-
ficant sites adjacent to or within the Des Plaines Tunnel
route. MSD is presently investigating areas adjacent to
planned tunnel routes. There are selected sites of historic
and architectural interest within the vicinity of the tunnel
route, but none within the immediate 500-foot impact area
of the tunnel. These sites are listed in Chapter III of
the EIS.
2.2.4 Financial Resources
Financial resources are currently available to fund the
Calumet Tunnel system. TARP's Phase I tunnel system cost
breakdown is approximately $1.46 billionl for water pollu-
tion elements and $0.69 billion for flood control measures.
Operation and maintenance of TARP has been estimated at
$13.6 million annually. The estimated cost of the Des Plaines
system alone is $346.9 million, with an annual maintenance
cost of $2.5 million.
Analysis of the funding resources required to finance
the Des Plaines Tunnel system reveals that sufficient funds
are currently available from the Federal Government, the
State, and the MSDGC. (See Section 3.3.1 of the EIS).
Additionally Federal Water Pollution Control funds of ap-
proximately $456.7 million will be required to meet the
implementation plan for all three conveyance tunnel systems.
In view nf the sound fiscal posture of the MSDGC, the high
funding priority assigned TARP by the State, and the very
conservative estimates of future Federal appropriations,
it can be reasonably assumed that future financing require-
ments can be satisfied.
Maintenance costs can either be covered through an ad
valorem property tax, or through a user charge system based
on water consumption. EPA favors the latter approach and
has awarded the MSDGC two grants to develop such a user
charge system.
Cost estimates based on values presented in MSDGC's "Facilities
Planning Study—MSDGC Overview Report," Revised, January 1975.
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2.2.5 Labor Resources
Labor resources are considered adequate to meet con-
struction and implementation needs of TARP and other proj-
ects. The diversified labor force in the Chicago metro-
politan area is vulnerable to economic recession because
of the emphasis upon manufacturing and nonservice employ-
ment. Thus, while national unemployment was about 8.4 per-
cent in the third quarter of 1975, Cook County had a 9.6
percent rate, and the city of Chicago sustained a 11.2 per-
cent rate of unemployment. Increasing productivity rates
and an expanding labor force should contribute to keeping
Chicago unemployment levels higher than the national rate
for the next few years. Therefore, new employment oppor-
tunities presented by TARP and other projects should not
experience a shortage of labor resources.
The labor force is predominantly male, with white
collar workers comprising 53 percent of the labor force in
the SMSA.
2.2.6 Transportation
Implementation of the Des Plaines Tunnel system will in-
volve the use of roadways and waterways. Trucks carrying
rock and spoil material from construction sites will utilize
several surface streets and expressways in reaching the
quarry or disposal site. The roadways range from dirt roads
to six-lane divided highways. The Des Plaines tunnel route
is proximate to the Des Plaines River although no waterborne
commerce is possible since the river is not physically
navigable.
2.2.7 Major Projects and Programs
There are no planned major projects and programs pro-
posed over the next 10 years in the vicinity of the Des Plaines
Tunnel route.
-XVI-
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III. THE PROPOSED ACTION
Identifying and defining a plan and its systems and
subsystems establishes the proposed action for which the en-
vironmental setting is described and the environmental im-
pacts are assessed. The proposed action identified and de-
fined for this EIS is the Phase I conveyance tunnel systems
and their associated subsystems only. The planned storage
reservoirs, waste treatment plant upgrading and expansion,
on-line reservoirs, and instream aeration facilities were
not included.
The information presented, in Chapter IV and V of the
EIS is summarized in this chapter and divided into seven
parts:
Alternative Plans
Plan Selector
TARP Tunnel Systems
TARP Subsystems
Des Plaines Tunnel Segments and Branches
Cost of Tunnel System and Subsystems
TARP Financing.
3.1 ALTERNATIVE PLANS
Many plans to resolve the Chicago area's flooding and
water pollution problems were developed during the past two
decades by concerned government agencies, local organiza-
tions, and individuals. At first, the plans focused prima-
rily on the flood control problem, however, as water quality
conditions in the area worsened, more emphasis was placed
on controlling the water pollution. A total of 23 plans
were formulated, and many were evaluated in detail by a
Flood Control Coordinating Committee (FCCC), consisting of
representatives from the State of Illinois, Cook County,
the MSDGC, and the city of Chicago.
In screening the alternative plans, the FCCC established
overall flood and pollution control objectives which pro-
vided a basis for evaluating alternative plans. A plan was
automatically rejected if it did not:
-xvii-
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Prevent all backflows to Lake Michigan to protect
water supply resources
Reduce pollutant discharges caused by combined-
sewer overflows
Reduce flooding in the combined-sewer and down-
stream areas.
In the initial screening, 6 plans were eliminated and
the remaining 17 were modified to meet the objectives more
fully as well as to provide a more quantitative basis for
comparison. The modifications were referred to as MODs,
and consisted basically of a combination of different sto-
rage capacities and waterway improvement actions. The
resulting MODS yielded 51 alternative subsystem plans, or
subplans, to be evaluated by the FCCC. In the next screen-
ing phase, the FCCC defined eight principal parameters,
including capital costs (1972 dollars), estimated annual
operating and maintenance costs (1972) , project benefits,
land acquisition acreage, underground easement requirements,
resident and business relocations, construction impacts,
and operation impacts. A technical advisory committee was
organized by the FCCC to evaluate the modified alternatives
in detail using the eight parameters. The advisory commit-
tee's interim report, "Evaluation Report of Alternative
Systems," recommended a 50,000 acre-feet (ac-ft) storage
level, which was part of the modified alternative designated
as MOD 3. After reviewing the report, the members of the
FCCC unanimously concluded that the flood and pollution con-
trol plan should be in the form of one of the four Chicago
Underflow plans developed (four of the seventeen plans) or
a combination of these plans, along with the recommended
storage level. The FCCC stated that, "These alternatives
are less costly and more environmentally acceptable to the
community than any of the other plans presented. Detail
studies along the lines of these alternatives should pro-
ceed to develop the final plan layout."
3.2 PLAN SELECTION
In August 1972, the FCCC members presented their final
recommendations in a report with seven technical appendices.
The report recommended consolidating the favorable features
of the four Underflow plans into the Tunnel and Reservoir
Plan (TARP). TARP was developed further and refined, then
-xviii-
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evaluated in detail with four selected alternatives and the
"no-action" alternative. In this evaluation, 15 significant
environmental impact parameters were identified as the basis
for evaluation. The FCCC concluded that very few negative
impacts are expected for any of the alternatives incorporat-
ing conveyance tunnels, and that adverse impacts will occur
if the "no-action" alternative is chosen. The FCCC also con-
cluded that the construction impacts of all plans on the en-
vironment will most likely be relatively short-term and local-
ized. Finally, the beneficial impacts of the plans will far
exceed the adverse impacts. Within*the scope of the FCCC
analysis, TARP had the highest ranking and was selected as
the most suitable plan to solve the flood and pollution prob-
lems of the Chicago metropolitan area.
TARP would provide the most benefits for the lowest
cost and the least adverse environmental impacts. Field
studies and subsurface exploration programs further refined
the plan/ however, they did not change the original TARP
concept. They were conducted only to optimize overall sys-
tem effectiveness. Presently, TARP will enable collection
of runoff water resulting from all but three of the severest
rainfall storms recorded during the past 21 years.
3.3 TARP TUNNEL SYSTEMS
The four tunnel systems that are a part of the Tunnel
and Reservoir Plan are the Mainstream, Calumet, Lower Des
Plaines, and O'Hare systems. Each system is a completely
independent operating unit with collection, storage, convey-
ance, and treatment capabilities. Figure III-l shows the
present routes and layout of these systems relative to the
MSDGC combined-sewer service area, the MSDGC overall service
area, and Cook County. Each of the TARP systems shown in
the figure consists of three component systems: reservoirs,
conveyance tunnels, and sewage treatment plants. A total
of three reservoirs, 120 miles of conveyance tunnels, and
four sewage treatment plants are included in the plan.
The TARP systems have two basic features which play a
major role in solving the flood and pollution problems.
First, the combined storage capacity of the plan is almost
136,800 ac-ft of which 127,600 ac-ft of the total is reser-
voir capacity and 9,200 ac-ft is tunnel capacity. The
planned treatment capacity of TARP will be approximately
2,240 MGD. Second, over 640 existing overflow points
will be eliminated within the MSDGC combined-sewer service
area by the TARP systems.
-XIX-
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FIGURE III-l
Tunnel and Reservoir Plan
System Layout and Routes
-xx-
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The proposed locations for the three reservoirs are:
McCook quarry, Thornton quarry, and an area northwest of
O'Hare International Airport. The conveyance tunnels,
located 150 to 290 feet below ground level, will be con-
structed under existing waterways and public rights-of-way.
Of the sewage treatment plants, three of the four plants
are currently activated sludge plants with a combined
planned capacity of approximately 2,150 MGD. The remaining
plant is the proposed O'Hare-Des Plaines plant which will
have a treatment capacity of over 70 MGD. A water reclama-
tion plant, the John F. Egan plant, is presently under con-
struction and the capacity will be 30 MGD.
3.4 TARP SUBSYSTEMS
The subsystems common to all TARP tunnel systems in-
clude drop shafts, collecting structures, and pumping sta-
tions. The drop shafts range from 4 to 15 feet in diameter
and have two basic designs. One design features a slotted
inner wall to assist in aerating the incoming water. The
wall separates the air shaft from the water shaft and allows
air either to enter or to escape while water is flowing in
or being pumped out. The other design features a separate
air shaft, to be installed in areas where high overflow rates
prevail. The inside diameter of this drop shaft design
ranges from 10 to 15 feet.
Approximately 640 collecting structures will be con-
structed to collect the overflows at established locations.
The collecting structure basically consists of a diversion
unit at the overflow point and a connecting pipe to the
drop shaft entrance chamber. Most of the new structures
will be constructed near curbs or in low points adjacent to
major public thoroughfares.
Pumping stations will be constructed underground at the
end of all conveyance tunnel routes and adjacent to all sto-
rage reservoirs. These stations permit a rate of dewatering
of the tunnels and reservoirs which will allow a full tunnel
or reservoir to be emptied within two to three days. The
stations will also be used to transport bottom sludge dredged
from reservoirs to treatment facilities.
-xxi-
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3. DES PLAINES TUNNEL SEGMENTS AND BRANCHES
The Des Plaines system of TARP consists of: one waste
treatment plant with a total capacity of approximately 220
MGD; over 26 miles of conveyance tunnel with a storage
volume of 1,668 ac-ft; and onw main storage reservoir with
a maximum capacity of 84,000 ac-ft. The component subsys-
tems associated with the Des Plaines system include 55 drop
shafts; and one pumping station located near the West-
Southwest Sewage Treatment Plant. The system and its com-
ponent subsystems will be constructed in one pahse.
This EIS addresses the TARP Phase I segments and
branches of the Des Plaines system and focuses only on the
conveyance tunnel system. The overall length of this tun-
nel system is approximately 26 miles. The subsystems
associated with it include 55 drop shafts, 5 construction
shafts, 10 access shafts, 80 collecting structures, and
1 pumping station.
3.6 COST OF TUNNEL SYSTEM AND SUBSYSTEMS
The MSDGC estimated cost of a 10-foot diameter tunnel
in rock with nominal aquifer protection is $200^ per lineal
foot. In rock with high quality aquifer protection, the
cost is $230. Tunnel cost for soft ground construction is
$350. Similarly, for a 35-foot diameter tunnel, the esti-
mated costs are-$l,030, $1,090, and $1,680 per lineal foot,
respectively.
Large rectangular tunnels adjacent to construction shafts
will be excavated by the drill and blast method and the estimated
cost with nominal aquifer protection is $2,090 per lineal foot
1 MSDGC, January 1975.
2 All cost figures presented in this section are based on 1972 values.
-xxii-
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for a 30-foot square tunnel. The same type and size of tun-
nels with high quality aquifer protection would cost an esti-
mated $2,170 per lineal foot.
The tunnel costs estimated above include the following
base figures:
Cost of muck disposal, estimated to be $4.00 per
solid cubic yard
Nominal grouting for control of infiltration
during construction, estimated to be $0.30 per
square foot of tunnel wall
Access and ventilation shaft construction
Ventilation and hoist equipment
Grout and grout inspection equipment
Average aquifer protection costs.
Additional grouting for aquifer protection in unlined tun-
nel segments in the upper aquifers is estimated to cost
$1.50 per square foot of tunnel wall. This grouting would
be provided to a depth of about one tunnel diameter beyond
the excavated tunnel limit.
The total construction cost for all the Phase I TARP
tunnel systems is approximately 1.46 billion. The estimated
total costs for the subsystems are: $93 million for collect-
ing/connecting structures, and $38 million for pumping
stations. These subsystem costs are based on the following:
Collecting Structures and Connecting Lines. The
cost of the near-surface collection structures
leading to the drop shafts includes the gravity
interceptor sewers and the necessary connecting
structures. Table III-l lists the costs for these
subsystems with respect to the TARP tunnel systems
Grouting is a procedure whereby a mixture of cement and water is
injected under pressure into a drilled hole that intersects a
source of seepage such as an open joint, fault, or bedding plane.
-xxiii-
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Table III-l
Estimated Costs For
Collecting Structures and Connecting Lines
Tunnel System
Mainstream
Calumet
Lower and Upper
Des Plaines
TOTALS
Estimated Cost ($ Million)
Intercepting
Structures
8.701
1.084
1.043
10.828
Collection
System
3.648
1.0S8
3.489
8.225
Total
12.349
2.172
4.532
19.053
Drop Shafts. The estimated cost of drop shafts
includes all drop shaft components. The costs are
related to the shaft diameter and to the depth of
penetration into the rock formations. The cost of
250-foot deep drop shafts varies from $80,000 for
a shaft two feet in diameter to $1,400,000 for a
20-foot diameter shaft.
Pumping Stations. The estimated construction cost
of pumping facilities includes the structure, pump-
ing equipment, power generation for the operation
of larger units, and discharge piping to the appro-
priate treatment plant. The estimates have been
based on use of variable-speed, motor-driven units,
Total capital costs for pumping vary as follows:
Lift
Height
300 feet
525 feet
Estimated Cost ($ Million)
Pumping Capacity
1000 cfs 100,000 cfs
5.6
5.7
200
300
3.7 TARP FINANCING
Financing of the entire $3.75 billion MSDGC Flood and
Pollution Control Plan over the next 11 years is doubtful.
As illustrated in Table III-2, however, the financing re-
quirements for all conveyance tunnels could be met by a
modest increase in Federal and MSDGC funding over a period
of 11 years, from 1976-1986. An additional $456.7 million
appropriation of funds are estimated to be required to
-XXIV-
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Table III-2
Financing Schedule - Tunnel Plan and Other Major Elements
of MSDGC Flood and Pollution Control Plan
x
i
I . Conveyance
Tunuuls
2 . Inst t cam
A<-rat Jon
u'^dW
Jt Calumet
1.1 Hog t -Sou i h-
•1 . Kuservol rs
-------
FOOTNOTES TO TABLE IIT-2
1 All cost estimates are based on those presented in the MSDGC's
Facilities Planning Study (January 1976) and are escalated 6
percent annually for inflation.
2 These funds represent the remainder of the FY 1975 and FY 1976
PL 92-500 appropriation which are expected to be allocated to
MSDGC by the State.
3 These are Federal funds, above and beyond the existing PL 92-500
appropriation, which are expected (in the form of a new appropria-
tion) over the period FY 1977-1982.
4 These are Federal funds above and beyond the additional $780 million
expected over the FY 1977-1982 period.
5 These are funds, under the State's current $750 million bonding
authorization, which are expected to be available to MSDGC to
finance the Tunnel Plan.
6 The funds in this category represented those available by virtue
of the unused bonding authority of the MSDGC under the current
$380 authorization.
7 This category represents funds expected to be available under an
additional $200 to $400 million bonding authority for which the
MSDGC is currently formulating plans to ask the State of Illinois.
8 There is no current COE appropriation for any MSDGC Flood and
Pollution Control Plan elements.
9 There is no near future COE appropriation expected for any MSDGC
Flood and Pollution Control Plan elements.
10 Includes approximately $49.6 million already obligated to the
North Shore section of the Mainstream Tunnel Plan (Addison-
Wilmette segment).
11 Figure doesn't include the estimated $124 million already obligated
for the O'hare treatment plant project.
12 The total estimated cost $3311.9 million differs from the $3750
million (Table 111-10 of the main body of the EIS) because of the
exclusion of the following projects: sewers, solids disposal,
O'Hare Treatment plant, and flood control (non-TARP).
-xxvi-
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finance the three (Mainstream, Calumet, and Lower Des
Plaines) TARP tunnel systems. The additional Federal
funds represent a modest portion (58.5 percent) of the
conservatively estimated $780 million of new PL 92-500
money which is expected to be forthcoming to MSDGC over
the next six fiscal years. Congress, however, has not
yet approved any additional appropriation beyond the
initial $18 billion which was authorized under PL 92-500
and totally allocated over the FY 1972-1976 period. The
$73.5 million of MSDGC funds represents an increase of
about 19 percent over the current MSDGC bonding autho-
rization. This amount, however, represents a very modest
proportion of the additional $200-400 million bonding
authorization for which MSDGC is currently formulating
plans to ask the State of Illinois.
If the Phase I tunnels of TARP are not implemented, there
is a very high probability that approximately 90 percent of
the currently available Federal funds assigned to the MSDGC
will be lost by both the State of Illinois and the 'MSDGC.
This potential loss to the MSDGC and state stems from the
fact that the Calumet treatmertt facility expansion project,
(which represent the next major project in terms of priority
for Federal funds) will not meet the September 30, 1977 dead-
line for Step 3 funding eligibility. Assuming this project
did not qualify in time for existing Federal funds, it is
estimated that only approximately 10 percent of the $323.6
million could alternatively be allocated to other MSDGC or
statewide prioritized pollution control projects.
The financing feasibility of other key elements (non-
Phase I TARP) of the MSDGC's Flood and Pollution Control
Plan (see Table III-2) , which are closely related to the
overall goal of meeting the 1983 water quality standards,
ranges from almost certainty to near zero. Addressing
these elements in the order of priority specified in the
MSDGC's 1975 Facilities Plan, instream aeration stands
slightly ahead of the conveyance tunnels. The approximately
$30.7 million required for instream aeration can easily be
met from existing state and MSDGC funding sources.1 It is
very unlikely, however, that the financing will be available
to increase the treatment levels, efficiencies, and capacities
at the Calumet and West-Southwest -treatment plants. The
total required financing ($1.13 billion) would necessitate
a significant increase above the additional levels of Federal
($780 million) and MSDGC ($200-400 million) funds expected
to be available over the FY 1977-1986 timeframe. The fi-
nancing feasibility of the Calumet treatment plant expansion,
however, is reasonable in view of their combined total
As of May 1976, funding for instream aeration has already been
authorized.
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estimated costs of $356.5 million. The Federal funding
portion ($267.4 million) could be provided from the additional
$780 million PL 92-500 appropriation expected over the next
six years. The MSDGC portion ($89.1 million) could be
provided from the anticipated $200-400 million additional
bonding authorization. In terms of the West-Southwest
treatment plant expansion project (estimated cost of $774.7
million), the financing feasibility is very questionable in
view of the requirement for additional funds beyond the
levels (Federal and MSDGC) expected to be available over
the period FY 1977 to 1986.
The operation and maintenance costs of the TARP tunnel
systems will be financed by a user charge system rather than
the current ad valorem tax system. PL 92-500 requires the
development of a user charge system and the State of Illinois
presently has the authority to impose a user charge. This
system of financing the annual operations and maintenance
costs of the tunnel systems is not expected to have a sig-
nificant economic impact in the commercial, industrial, and.
household sectors. The incremental charge in the MSDGC tax
rate per $100 of assessed valuation (1975 rate was $.4005)
is estimated to be $.0736 (for operations and maintenance)
and $.002 (for tunnel construction) by the year 1936. The
tunnel construction impact will continually decline after
1986 with the continuing growth of the tax base. Details
of this financial system are provided in the EIS in Sections
3.3.1 and 9.3.
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IV. PRINCIPAL FINDINGS CONCERNING THE EFFECTS
OF THE PROPOSED ACTION
Chapters VI through IX of the EIS assess the beneficial
and adverse effects of the construction and operation of the
conveyance tunnel systems on greater Chicago's natural and
man-made environments. This chapter presents the principal
findings of that analysis only for those effects expected
to be relatively significant.
The most significant finding relates to the expected
improvement in water quality resulting from the operation
of the three Phase I tunnel systems. To assess the signi-
ficance of this improvement, the EIS includes the considera-
tion of the possible and likely cumulative effects of TARP
components which are not a part of the Phase I systems. These
other components are the reservoirs, treatment plant improve-
ments, and instream aeration.
The principal findings of the EIS are listed as follows:
(1) Effects of Operation on Water Quality
(2) Funding Uncertainty for TARP
(3) Effects of Rock Spoil Generated During Construction
(4) Effects of Construction on Employment
(5) General Effects of Construction
(6) Effects of Infiltration and Exfiltration
(7) Worker Safety During Construction
(8) Effects of Operation on Land Use
(9) Effects of a Significant Earthquake on Tunnel System
(10) Effects of Flooding on Lake Michigan.
EFFECTS OF OPERATION ON WATER QUALITY
THE TUNNEL WILL SIGNIFICANTLY REDUCE THE POLLUTANT LOAD
CURRENTLY DISCHARGED TO CHICAGO'S WATERWAYS, HOWEVER,
THE TUNNELS ALONE WILL NOT RESULT IN ATTAINING APPLI-
CABLE ILLINOIS WATER QUALITY STANDARDS, AND, THEREFORE,
WILL NOT ENABLE ADDITIONAL USES OF THE AFFECTED WATER-
WAYS. THE ATTAINMENT OF ILLINOIS WATER QUALITY STAN-
DARDS DEPENDS ON ADDITIONAL CONTROL MEASURES FOR WHICH
THE FUNDING PROSPECTS ARE NOW POOR.
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This conclusion is based on the following findings:
The tunnels will capture approximately 90 percent
of the pollutant load now discharged during com-
bined-sewer overflows and v/ill reduce the pollu-
tant load 75 percent overall and the frequency of
overflows from 100 to 10 times per year. 1977
Illinois water quality standards will continue to
be violated during overflow events because of un-
controlled injections of pollutants into the water-
ways.
The tunnels may not result in the attainment of 1977
Illinois standards for ammonia over lengthy reaches
of waterway, because high concentrations of this
pollutant are discharged from local wastewater
treatment plants. Although data are not presently
available to allow a more definitive determination
of effects on this point, the attainment of water
quality standards in the area's major river systems
is clearly and intimately tied to the upgrading
and expansion of MSDGC treatment plants.
With the tunnels on line, 1977 Illinois standards
of 4 mg/1 for dissolved oxygen (DO) will still be
violated along approximately 50 of the 80 miles
of the Main Channel and of the Calumet River sys-
tems during the critical late summer months. Con-
ditions along the Des Plaines River system have not
yet been modeled by the MSDGC, but will be com-
pleted under the Section 208 planning program.
1977 Illinois standards for DO are likely to be
met over the entire 80-mile length of the modeled
waterways during critical summer dry flow condi-
tions, assuming implementation of the following
pollution control components:
Tunnels
Reservoirs
Treatment plant improvements
Instream aeration.
The water quality impact of these various pollu-
tion control options is summarized in Table IV-1.
Given current projections of Federal, state, and
MSDGC financing capabilities and policies, the fi-
nancing of the tunnels and instream aeration-ap-
pears secure. The financing of the Calumet treatment
-xxx-
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Notes
Table IV-1
Impact of Potential Pollution Control Options
on Water Quality Along Main Channel
and Calumet River Systems1
(a) Tunnels plus instream aeration effects addressed in Section 8.1.1 of EIS
(b) Phasing of options shown in order adopted by MSDGC in modeling studies.
I
X
X
H-
I
\Pollution
Watcr\ Control
Quality\°ljtl0n
Component \
Combined-Sewer
Overflows
Ammonia l.cvels
Dissolved
Ox y yen (DO)
Concentra-
tions^
Allowable
Water Uses
No
Act i on
Overflow to
waterways 100
times per year.
Illinois stan-
dards violated
most of. the
time.
Ammonia stan-
dard violated
by treatment
plant dis-
charges .
DO lovely below
Illinois stan-
dards alotuj 80
percent of
waterways. An-
aerobic condi-
tions exist
over larqe
stretches.
Illinois water
use standards
not mot alony
area waterways.
Phase I
Tunnels
Overflows reduced
from 100 to ID per
year. 75 percent
of pollutant load1
captured and
treated.
Ammonia standard
violated due to
treatment plant
d i st_'harges .
DO levels bulow
Illinois standards
along 70 percent
of waterway. An-
aerobic conditions
greatly relieved.
No significant
change
Phase 1
Tunne ly
PUjs
I nst roam Aeration
No significant change
No significant
change
Illinois standard
met over entire 80-
mile length of water-
way. Anerobic con-
ditions completely
eliminated.
No significant
change
Tunnels Plus
Treatment Rant
Upgrading2 Plus
Instream Aeration
No siynificant change
Ajtunonia standard met
most of the time (not
during overflow
cpi sodes) .
No siynificant
change
No siynificant change
Tunnels 1'J us
Ueservoiis 1'Tus
Treatment l*lant Upgrading
Plus innlrouiu Aeration
Overflows reduced to
four occasions in 2D
years. St.indards met
in waterways even dur-
ing these rare over-
flow , 'vents.
Ammon i ,1 ) t-vo Is in
w.iterwjys improved
beyond standard.
No significant
change
Illinois water use
standards met. Pish-
ing , boating, nnd
shoreline activities
permi tted.
Computer sumi lations of water ijud Li ty alon«j the l)es Plainus Kivor not yet available.
Upij radiny to t or t i tiry I eve 1 assumod wa t h ru t coqen and phosphoi us fGmova 1 .
Kv a lua Led for di/y went hoi f) ow cond i t i ons .
Computer simulations of dry weather flow conditions.
-------
plant expansion is probable; but financing the
costly West-Southwest Treatment Plant is very
doubtful. The financing of the reservoirs in the
near future is very unlikely given the absence of
any Federal commitment to provide assistance.
Additional details on water quality are provided in Sec-
tions 2.1 and 8.1 of the EIS text and details on financing
in Section 3.3.1.
2. FUNDING UNCERTAINTY FOR TARP
THE CONVEYANCE TUNNELS CAN BE FINANCED BETWEEN 1976-
1987 WITH MODEST INCREASES IN ANTICIPATED FEDERAL AND
LOCAL FUNDING. HOWEVER, THE FUNDING OF THE RESERVOIR
DURING THIS TIME PERIOD IS NOT A PART OF THE CURRENT
FINANCING PLAN AND COULD NOT BE ACCOMPLISHED WITHOUT
HAVING A MAJOR FINANCIAL IMPACT ON THE STATE, CITY, OR
MSDGC.
Additional details on this finding may be found in Sec-
tion 3.3.1 of the EIS.
3. EFFECTS OF ROCK SPOIL GENERATED DURING CONSTRUCTION
THE ROCK SPOIL MATERIAL GENERATED DURING TUNNEL CON-
STRUCTION IS NOT EXPECTED TO BE MARKETABLE. THEREFORE,
ENVIRONMENTAL IMPACTS ASSOCIATED WITH DISPOSAL OF THE
ROCK SPOIL WILL DEPEND LARGELY ON THE AVAILABILITY OF
LANDFILL DISPOSAL SITES.
Approximately 3,784,000 cubic yards (bulk measure) of
spoil will be removed from the Des Plaines tunnel segments
and branches. Although this amount can be adequately con-
tained within area quarries, approximately 2,200,000 cubic
yards of spoil will be stored on Forest Preserve lands for
•.-.heir use. Disposal of rock spoil from the reservoirs was
addressed briefly in Section 6.2.4 of the EIS. A signifi-
cant portion of rock spoil generated by reservoir construc-
tion is likely to be marketable and to be stockpiled on the
cuarry site for eventual sale by the quarry owners.
Major findings supporting the above conclusions are:
Shale and other constituents present in the rock
excavated from the Phase I tunnels will limit the
rock's suitability for low-grade commercial uses.
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Landfill disposal sites capable of accepting the
entire volume of tunnel spoil to be generated dur-
ing TARP Phase I have not yet been identified by
the MSDGC.
McCook Quarry has enough volume to accept the en-
tire quantity of spoil to be excavated from the
Des Plaines tunnel segments and branches.
Since conventional methods will be used to exca-
vate rock from area quarries for reservoir con-
struction, it is likely that a significant portion
of the spoil will be marketable. Present plans
envision stockpiling the saleable portion on the
quarry sites for eventual sale by the quarry owners
Various stockpile configurations are being con-
sidered. Non saleable spoil can be stockpiled on-
site, as is proposed for the McCook Quarry site.
A more detailed discussion is provided in Section 6.2.4
of the EIS.
4. EFFECTS OF CONSTRUCTION ON EMPLOYMENT
CONSTRUCTION OF THE DES PLAINES TUNNEL WILL PROVIDE
ABOUT $87 MILLION IN CONSTRUCTION INCOME OVER A 7-YEAR
PERIOD AND WILL CREATE A PEAK SUPPLY OF APPROXIMATELY
548 JOBS OVER A 3-YEAR PERIOD.
Further information may be found in Section 7.1.3.
5. GENERAL EFFECTS OF CONSTRUCTION
CONSTRUCTION OF THE TARP TUNNEL SYSTEMS WILL RESULT IN
TEMPORARY PUBLIC ANNOYANCE AND INCONVENIENCE FROM THE
CUMULATIVE EFFECTS OF NOISE, HANDLING OF CONSTRUCTION
DEBRIS, VIBRATION FROM BLASTING, DISRUPTION OF VEHICULAR
AND PEDESTRIAN TRAFFIC, AND GLARE FROM THE ILLUMINATION
OF CONSTRUCTION AREAS AT NIGHT. ALTHOUGH THE CUMULATIVE
EFFECTS MAY BE NOTICEABLE, TAKEN SINGLY, EACH EFFECT IS
MINOR.
This conclusion is supported by the following findings:
Surface construction sites are located in areas
which are generally either vacant or near low-
utilized industrial land.
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Noise at each construction site should be within
levels mandated by Chicago ordinances and, at each
surface construction site, noise will only occur
for periods of 3 to 9 months.
Because blasting will be used only to excavate shafts
and not the tunnel, itself, blasts will be relatively
infrequent and will continue at any one site for not
more than 120 days.
Further information on this subject may be found in
Sections 6.3.1, 6.3.2, 7.1.1, 7.2.1, 7.4, and 10.2.
EFFECTS OF INFILTRATION AND EXFILTRATION
IF THE GROUTING PROGRAM IS NOT EFFECTIVE, GROUNDWATER
INFILTRATION DURING CONSTRUCTION AND WASTEWATER EXFIL-
TRATION DURING TUNNEL OPERATION CAN BE A SIGNIFICANT
PROBLEM.
This conclusion is supported by the following findings:
The inflow rate of groundwater for the TARP tunnel
systems is estimated to be an average of approxi-
mately 0.5 MGD per mile of tunnel. In the absence
of appropriate mitigative measures, this rate is
sufficient to lower the piezometric or hydraulic
pressure level of the upper aquifer. Tunnel grout-
ing is the most effective method to reduce infil-
tration and a grouting program has been incorporated
in TARP. Grouting integrity, however, must be main-
tained to keep inflows below the allowable limit
of 500 gallons per day per inch of tunnel diameter
per mile of tunnel. Observation wells will be re-
quired to monitor integrity throughout the opera-
tional phase of the tunnel.
Exfiltration will most likely occur when tunnel
pressures exceed inflow pressures during high
storm runoff conditions. The TARP grouting pro-
gram is expected to prevent extensive exfiltration
of tunnel wastewaters into the upper aquifer.
The objective of grouting is to achieve maximum penetration and a
uniform grout spread. If grouting is ineffective, maximum infil-
tration/exfiltration flows will result.
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However, if grouting integrity is not maintained
during tunnel operation, exfiltration will be at
a high enough rate to degrade groundwater quality
of the upper aquifer. Observation wells will be
necessary to determine whether exfiltration is oc-
curring along the tunnel routes.
EIS Sections 2.1.2, 6.1.2, and 8.1.2 provide more in-
formation on the subject of groundwater infiltration and
wastewater exfiltration. Specifications for observation
well spacing and for the monitoring program are also pre-
sented in these sections.
7. WORKER SAFETY DURING CONSTRUCTION
TUNNEL OR UNDERGROUND CONSTRUCTION WORKERS WILL BE MORE
SUSCEPTIBLE TO INJURY, DISABILITY, AND FATALITY THAN
SURFACE CONSTRUCTION WORKERS. THE INCIDENCE OF INJURIES
AND FATALITIES, HOWEVER, IS NOT EXPECTED TO BE. GREATER
THAN NORMAL FOR THIS TYPE OF CONSTRUCTION WORK.
This conclusion is supported by the following findings:
Based on recent national statistics for all types
of construction activities, the Des Plaines Tunnel
system construction may result in 84 disabling in-
juries and in one permanent disability or fatality.
For construction of the entire tunnel system, in-
juries and fatalities are expected to increase pro-
portionately.
Based on the safety statistics of the current con-
struction of a rapid-transit system subway in Wash-
ington, D.C., construction of the entire TARP tun-
nel system could result in 1,525 injuries and in
9 fatalities.
Analysis of the geologic and seismic characteris-
tics of the project area indicates that most of
the area is stable and suitable for the construc-
tion of underground tunnels. Precautionary measures
will be required to protect workers in segments
where rockfall and partings (loosened material) may
occur frequently and shale deterioration conditions
prevail.
Further information on this subject may be found in Sec-
tions 6.2.2 and 7.1.2.
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8. EFFECTS OF OPERATION ON LAI-TD USE
THE QUALITY OF LAND IN CERTAIN RIVERBANK SECTIONS ALONG
THE DBS PLAINES TUNNEL ROUTE MAY BE ENHANCED BY REDUCED
FLOODING CONDITIONS.
Vacant land exists in the flood-prone areas associated
with the Des Plaines Tunnel system. The reduction of flood-
ing in these areas may enable development of this under-
utilized land into open space uses such as: parks, play-
grounds, sport fields, and parking areas.
9. EFFECTS OF A SIGNIFICANT EARTHQUAKE ON TUNNEL SYSTEM
IF A SIGNIFICANT EARTHQUAKE OCCURS IN THE CHICAGO AREA,
THE EVENT MAY OFFSET TUNNEL ALIGNMENT AND CAUSE SIGNI-
FICANT DAMAGE TO PORTIONS OF THE TUNNEL SYSTEM.
This conclusion is based on the following findinas:
The 175-year historical earthquake records indicate
that a seismic event with a Modified Mercalli In-
tensity (MMI) of VIII can recur in the Chicago area
at a rate of about once per 100 years. Assuming
the tunnel system is in operation for 100 years,
the probability of this event occurring at some
time during this period is 100 to 1 or 10,000 to
1 for any given year. If an MMI VIII event occurs,
severe alterations to tunnel alignment or tunnel
surface may result.
The conveyance tunnels will pass through several
active faults prevalent in the TARP project area
and will be sensitive to earth movement at these
locations. Information on the distribution and na-
ture of the active faults is insufficient to assess
accurately the extent of damage which could result
from an MMI VIII earthquake.
Further information on this subject may be found in Sec-
tions 2.2.3, 2.2.4, and 8.2.2 of the EIS.
10. EFFECTS OF FLOODING ON LAKE MICHIGAN
THE FLOODING PROBLEM EXISTING IN THE CHICAGO AREA WILL
NOT BE RESOLVED BY THE PHASE I TUNNELS. OVERFLOW TO
LAKE MICHIGAN WILL STILL PERSIST IF THE PROPOSED RESER-
VOIRS ARE NOT IMPLEMENTED.
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V. CONCLUSIONS AND RECOMMENDATIONS
The following is a summary of the principle conclusions
of the Draft EIS, as well as recommended and suggested miti-
gative measures.
1. Implementation of the Lower Des Plaines System will
significantly reduce the pollutant load in the Chicago water-
ways. These loadings will be reduced further with the imple-
mentation of the Mainstream and Calumet Tunnel systems.
Water quality will be enhanced further with the upgrading of
MSDGC's treatment facilities and the construction of the flood
control aspects of the Tunnel and Reservoir Plan.
2. The rock spoil excavated from the Phase I tunnels is
not expected to be marketable. Evaluation of various disposal
alternatives leads to the conclusion that adequate environ-
mentally acceptable landfill sites are available to handle
the volume of rock which will be generated by the Phase I
tunnels under consideration. We will rely on existing local,
state, and Federal regulations to insure that disposal takes
place in an acceptable manner. Additionally the MSDGC will
be required to inform USEPA of their spoil disposal program
as it is developed through discussion with the Contractor.
This will be a condition of any grant awarded to the MSDGC
for the Lower Des Plaines Tunnel System.
3. Although an effective grouting program is proposed,
it must be sufficiently flexible to respond to the actual
conditions encountered during construction. Should the
grouting not be sufficient, additional infiltration could
adversely affect the hydraulic pressure of the upper aquifer.
Additionally, under surcharged conditions, exfiltration
will occur, resulting in adverse impacts on the groundwater
quality of the upper aquifer. Observation wells to monitor
grouting integrity during operation are necessary along
the entire tunnel alignment. If pollutants are detected
in the observation wells, additional mitigative measures
must be implemented to protect the upper aquifer, including
a groundwater recharge system. Chapter X discusses particular
aspects of the monitoring program, which will be developed
in conjunction with the MSDGC, IEPA and USEPA. This monitoring
program will also be a grant condition.
4. Since the majority of the construction shafts and
drop shafts are in close proximity to area waterways, runoff
from these sites could adversely affect water quality. Berms
will be constructed around stockpiles of construction materials
and spoil materials to preclude runoff into the waterways.
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5. It is presently proposed that water pumped from the
tunnels during construction be discharged directly to the
waterways after a period of settling. Since the possibility
of silt and other pollutants still exists after settling, it
is recommended that, wherever possible, these dewatering flows
be discharged to MSDGC's intercepting system for treatment,
except during periods of combined sewer overflows. This will
be a condition of any grant awarded for the Lower Des Plaines
Tunnel System.
6. Conformance with applicable regulation of the Occupa-
tional Health and Safety Administration, U.S. Department of
Labor, and the Bureau of Mines, U.S. Department of the Interior
is essential for safety of construction workers.
7. Significant earthquake events could adversely affect
tunnel alignment and tunnel lining. Smaller earth movements
could also affect the lining and grouting of the tunnels. It
is, therefore, essential that MSDGC's inspection and main-
tenance program be extensive enough to insure efficient
operation of the system.
8. There exists a wide range of potential adverse impacts
which could develop during construction. This includes blasting,
waste spillage, traffic congestion, light glare/ and fugitive
dust at construction and disposal sites. While these effects
could be considered insignificant any measures taken to reduce
their impact would aid in public acceptability of the project.
These suggested mitigative measures are discussed in Chapter X.
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* U.S. GOVERNMENT PRINTING OFFICE: 1977—751-667
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