905R76104
DRAFT ENVIRONMENTAL
IMPACT STATEMENT
For the
TUNNEL COMPONENT OF THE TUNNEL
AND RESERVOIR PLAN (TARP)
PROPOSED BY THE METROPOLITAN
SANITARY DISTRICT OF GREATER
CHICAGO
MAINSTREAM TUNNEL SYSTEM,
59th STREET TO ADDISON STREET
t
t
Prepared by
United States Environmental Protection Agency
Region V
Chicago, Illinois 60604
March 1976
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DRAFT
ENVIROMffiNTAL IMPACT STATEMENT
TUNNEL COMPONENT OF THE
TUNNEL AND RESERVOIR PLAN
PROPOSED BY THE
METROPOLITAN SANITARY DISTRICT
OF GREATER CHICAGO
MAINSTREAM TUNNEL SYSTEM
59th STREET TO ADDISON
Prepared by
United States Environmental Protection Agency
Region V
Chicago, Illinois
and
Booz, Allen and Hamilton Inc.
Bethesda, Maryland
APPROVED BY
Regional AdminstMtor
March 1976
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SUMMARY SHEET
(x) Draft
( ) Final
U.S. Environmental Protection Agency
1. (x) Administrative Action
( ) Legislative Action
2. Description of the Action - see Executive Summary, pgs. xix to xxiv
3. Environmental Impact - see Executive Summary, pgs. xxv to xxxiv
4. Alternatives Considered - see Executive Summary, pgs. xvi to xviii
5. Federal, State, and Local Agencies and Individuals Notified of this Action
Senator Adlai E. Stevenson, III
Senator Charles H. Percy
Representative George M. O'Brien
Representative Philip M. Crane
Representative Frank Annunzio
Representative Abner J. Mikva
Representative Sidney R. Yates
Representative Dan Rostenkowski
Representative Martin A. Russo
Representative Candiss Collins
Representative Henry J. Hyde
Representative John G. Fary
Representative Edward J. Derwinski
Representative Morgan F. Murphy
Representative Ralph H. Metcalfe
Water Resources Council
Council on Environmental Quality
Environmental Protection Agency
Office of Federal Activities
Office of Public Affairs
Office of Legislation
Office of Water Programs Operations
Environmental Evaluation Branch
Department of Interior
Bureau of Outdoor Recreation
Fish and Wildlife Services
National Park Service
Geological Survey
Bureau of Mines
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Department of Defense
Army Corps of Engineers
North Central Division
Chicago District Office
Department of Agriculture
Soil Conservation Service
Forest Service
Department of Health, Education, and Welfare
Department of Housing and Urban Development
Department of Transportation
Federal Aviation Administration
Coast Guard
Department of Comnerce
National Oceanic and Atmospheric Administration
Department of Labor
Occupational Health and Safety Administration
Great Lakes Basin Commission
Governor of Illinois
Illinois Institute for Environmental Quality
Illinois Environmental Protection Agency
Illinois Division of Waterways
Illinois Department of Public Health
Illinois Department of Conservation
State Historic Preservation Office
Bureau of Emrironmental Science
Business and Economic Development
Bureau of Soil and Water Conservation
Northeastern Illinois Planning Commission
Cook County Department of Environmental Control
Metropolitan Sanitary District of Greater Chicago
City of Chicago
Department of Environment Control
Department of Development and Planning
Department, of Aviation
Public Libraries
Others
6. Dates Draft Statement made available to:
The Council on Environmental Quality March 5, 1976
The Public March 12, 1976
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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 Mainstream Tunnel System from
59th Street to Addison Street. Copies of the Draft EIS
may be obtained by writing the U.S. Environmental Protec-
tion 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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TABLE 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-
2.2 Man-made Environment -xii-
2.2.1 Socioeconomic -xii-
2.2.2 Land Use -xiii-
2.2.3 Sensitive Areas -xiv-
2.2.4 Financial Resources -xiv-
2.2.5 Labor Resources -xv-
2.2.6 Transportation -xv-
2.2.7 Major Projects and Programs -xv-
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 -xix-
3.5 59th-to-Addison Tunnel Segment -xxii-
3.6 Cost of Tunnel System and Subsystems -xxii-
3.7 TARP Financing -xv-
IV. PRINCIPAL FINDINGS CONCERNING THE EFFECTS OF
THE PROPOSED ACTION -xxv-
V. CONCLUSIONS AND RECOMMENDATIONS -xxxx
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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-
fects of the tunnel system to be significant.
This EIS is being issued pursuant to P.L. 91-90, the
National Environmental Policy Act (NEPA) of 1969, and Exe-
cutive Order 11514, "Protection and Enhancement of Environ-
mental Quality" dated March 5, 1970. Both NEPA and Execu-
tive Order 11514 require that all Federal agencies prepare
such statements in connection with their proposals for major
Federal actions significantly affecting the quality of the
human environment.
Authorized by Title II, Section 201(g)(l), of the Federal Water
Pollution Control Act Amendments of 1972, Public Law 92-500 (FWPCA.A)
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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-Parg 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 a segment of the Mainstream
Tunnel system route from 59th Street to Addison Street. Two
subsequent statements will address separately the effects
associated with the Calumet Tunnel system and the Lower Des
Plaines Tunnel system. These tunnel systems comprise what
is referred to in the statement as "TARP, Phase 1."
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
COMBINt D '.
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." 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 and one
lakes. These surface water systems include the Chicago
River, the Sanitary and Ship Canal, the Calumet River sys-
tem, 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 (BOD)
Ammonia (as N)
Suspended solids (SS)
Fecal coliform
Chicago River
Sanitary and
Ship Canal System
1.2 to 7.7 mg/1
5.2 to 9.2 mg/1
0.8 to 6.2 mg/1
19 to 54 mg/1
477 to 12,700
(counts/100 ml)
Ca 1 umot Rivor
Dyolem
i.9 to 9.0 mg/1
4.1 to 7.3 mg/1
1.3 to 13 mg/1
12 to 73 mg/1
152 to 738
(counts/100 ml)
Des Plaines
River System
6.0 to 10 mg/1
5.0 to 6.7 mg/1
0.3 to 1.2 mg/1
29 to 68 mg/1
411 to 8,700
(counts/100 ml)
Applicable
Illinois
Standard
4.0 mg/1 (1973) l
5.0 rng/1 mm.
10 mg/13
4.0 mg/11
1.5 mg/1
12 mg/13
1000/100 ml1
200/100 ml
1 Secondary Contact and Indigenous Aquatic Life Standards applicable to Chicago River-Sanitary and Ship
Canal system and Calumet River :,ystem.
2 General tjse Standard applicable to DCS Plaines River ^ystoms.
3 Effluent Discharge Standard.
Serious public health problems involving contamination
of Chicago's drinking water supply has led to implementa-
tion 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 drink-
ing 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, in-
direct 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 water quality
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. Combined-sewer
overflows, which occur about 100 times per average year,
inject pollutants in large amounts into waterways at approxi-
mately 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).
2.2 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).
Chicago 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. Construction
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 accounted 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 con-
struction services.
2.2.2 Land Use
The predominant land use bordering the Mainstream Tunnel
route can be characterized by its industrial zoning; large
portions are underutilized and vacant. The notable exception
to industrial land use is commercial development characteris-
tic of the Central Business District (CBD) which borders the
tunnel segment following the Chicago River from Lake Michigan
to Wolf Point. There are no residential land uses border-
ing the tunnel route. Rock taken from the tunnel will pro-
bably will be disposed of 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
landfill, NuEarch, broker sales, Landale Lagoons, and other
landfills.
The land areas bordering the proposed tunnel route are
expected to change to park, cultural, and recreational uses
in the CBD-related sections but remain generally the same
along other segments. Implementation of the Chicago 21 Plan
would realize the Riveredge Plan, affecting redevelopment
bordering the Main Branch of the Chicago River from Lake
Michigan to Wolf Point. Substantial new recreational park
development along the riveredges are envisioned.
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Plans also call for the strengthening of the North
Branch Industrial Area. Industrial uses along the Sanitary
and Ship Canal are likely to continue because of the need
for low-cost water transport. Improved water quality in
the river and the canal plus storm water management would
enhance the proposed Riveredge Plan and would help strengthen
the industrial areas.
2.2.3 Sensitive Areas
There are no known archeological or historically signif-
icant sites bordering the 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 on pages 111-16 and 111-17 of the EIS.
2.2.4 Financial Resources
Financial resources are currently available to fund the
Mainstream Tunnel system. TARP's Phase 1 tunnel system cost
breakdown is approximately $1.03 billion1 for water pollution
elements and $8.1 billion for flood control measures. Opera-
tion and maintenance of TARP has been estimated at $1.0 mil-
lion annually. The estimated cost of the Mainstream system
alone is $508.2 million, with an annual maintenance cost of
of $472,000.
Analysis of the funding resources required to finance
the Mainstream 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). Ad-
ditionaly Federal Water Pollution Control funds of approxi-
mately $221.0 million and MSDGC funds of about $73.5 million
will be required to meet the implementation plan for the other
conveyance tunnel systems. In view of 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 fi-
nancing requirements 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
Planninq StudyMSDGC Overview Report," 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 Mainstream Tunnel system will in-
volve 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 sites. The roadways range from two-lane streets to
six-lane divided highways. The Mainstream Tunnel route
also is proximate to major Chicago waterways; the North and
South Branches of the Chicago River and the Sanitary and
Ship Canal. Other portions of TARP will be near the Calumet
and Little Calumet Rivers, and the Calumet-Sag Channel. Water-
borne commerce is important to the Chicago economy; of the
46.2 million tons of waterborne freight traffic handled
by the Port of Chicago, 37 percent of 17.3 million tons
are moved over the inland waterways.
2.2.7 Major Projects and Programs
Major projects and programs proposed over the next ten
years in the vicinity of the Mainstream Tunnel route consist
mainly of transportation system improvements. Major trans-
portation-related improvements which are proposed include:
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Monroe Street Subway Line
Franklin Street Subway Line
Crosstown Expressway
Columbus Avenue - Monroe to Wacker, and northside
of the Main Branch to Ontario Street
Lake Shore Drive - relocation and construction from
Monroe to Wacker
Ashland Avenue - improvements from 83rd Street to
Addison Street
Rail and truck terminal improvements.
Other public projects include the proposed acquisition
of rights-of-way along the north side of the Sanitary and
Ship Canal. These rights-of-way are privately owned, and
used by Commonwealth Edison and Natural Gas Pipeline Com-
pany of America for energy transmission. The intent of the
public acquisition would be to establish a permanent utility
corridor to more efficiently service growing energy demands.
An addition to Lane Technical High School is proposed,
which is near drop shaft number 85, and two construction
shafts just south of Addison Street on the east side of the
North Branch. No other expansion plans are proposed in the
vicinity of the tunnel project.
-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
59th-to-Addison Tunnel Segment
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
subp]ans, 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
- XV1JL1-
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evaluated in dr.'tail 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 ncqativo
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 IJI-1 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
115,000 ac-ft of which 105,800 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
2,400 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
r
-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 17 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 17 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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3.5 59TH-TO-ADDISQN TUNNEL SEGMENT
The Mainstream system of TARP consists of: two waste
treatment plants with a total capacity of approximately
1,800 MGD; over 57 miles of conveyance tunnel with a storage
volume of 3,180 ac-ft; and one main storage reservoir with
a maximum capacity of 64,000 ac-ft. The component subsys-
tems associated with the Mainstream system include 134
drop shafts; over 220 collecting structures; and two pump-
ing stations, with one station located at the main storage
reservoir. The system and its component subsystems will
be constructed in two phases. In Phase I, approximately
40 miles of tunnel will be constructed, and in Phase II, the
remaining 17 miles will be constructed. The Phase II tunnel
route is almost parallel to the 59th-to-Addison segment of
the Phase I tunnel, as shown in Figure III-l, and it will be
used as a relief tunnel.
Phase I construction has already commenced on the North
Shore Channel segment and on the North Branch-Chicago River
segment. These segments, therefore, are not addressed in
the Mainstream EIS. This EIS addresses the Phase I, 59th
Street to Addison Street segment of the Mainstream system
and focuses only on the conveyance tunnel system. The
overall length of this tunnel segment is approximately
21 miles. The subsystems associated with it include 82 drop
shafts, 5 construction shafts, 2 access shafts, 170 collect-
ing structures, and 1 main 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 $1,030, $1,090, and $1,680 per lineal foot,
respectively.
Large rectangular tunnels will be excavated by the drill
and blast method and the estimated cost with nominal aquifer
protection is $2,090 per lineal foot for a 40-foot diameter
1 MSDGC, January 1975.
2 All cost figures presented in this section are based on 1972 values.
-xxii-
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tunnel, and $2,580 for a 49-foot diameter tunnel. The same
type and size of tunnels with high quality aquifer protec-
tion would cost an estimated $2,170 and $2,770 per lineal
foot, respectively.
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 TARP tunnel
systems is approximately $567 million. The estimated total
costs for the subsystems are: $93 million for collecting/
connecting structures, and $38 million for pumping stations
These subsystem costs are based on the following:
Grouting is a procedure whereby a mixture of cement and water is
injected under pressure into a drilled hole that intersects a
source of seepage such as an open joint, fault, or bedding plane.
-xxiii-
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Collecting Structures and Connecting Lines. The
cost of the near-surface collection structures
leading to the drop shafts includes the gravity
interceptor sewers and the necessary connecting
structures. Table III-l lists the costs for these
subsystems with respect to the TARP tunnel systems
Table III-l
Estimated Costs For
Collecting Structures and Connecting Lines
Tunnel System
Mainstream
Calumet
Lower and Upper
Des Plaines
TOTALS
Estimated Cost ($ Million)
Intercepting
Structures
8.701
1.084
1.043
10.828
Collection
System
3.648
1.088
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 $1,400,000 for a
20-foot diameter shaft. Continued development of
the "raise-bore" machines could reduce the cost
of shafts in rock by reducing excavation costs and
by eliminating concrete linings.
Pumping Stations. The estimated construction cost
of pumping facilities includes the structure, pump-
ing equipment, power generation for the operation
of larger units, and discharge piping to the appro-
priate treatment plant. The estimates have been
based on use of variable-speed, motor-driven units
Total capital costs for pumping vary as follows:
Lift
Height
300 feet
525 feet
Estimated Cost ($ Million)
Pumping Capacity
1000 cfs 100,000 cfs
5.6
5.7
200
300
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3.7 TARP FINANCING
Financing of the entire $3.54 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 $220.0 million
appropriation of Federal funds and an additional $73.5 mil-
lion of MSDGC funds are estimated to be required to finance
the three (Mainstream, Calumet, and Lower Des Plaines) TARP
tunnel systems. The additional Federal funds represent a
modest portion (28.3 percent) of the conservatively esti-
mated $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 rep-
resents an increase of about 19 percent over the current
MSDGC bonding authorization. This amount, however, repre-
sents a very modest proportion of the additional $200-400
million bonding authorization for which MSDGC is currently for-
mulating plans to ask the State of Illinois,
If the tunnel phase of TARP is 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 and North-Side treatment facilities
expansion project, (which represent the next major projects
in terms of priority for Federal funds) will not meet the
September 30, 1977 deadline for Step 3 funding eligibility.
Assuming these two projects did not qualify in time for
existing Federal funds, it is estimated that only approxi-
mately 10 percent of the $323.6 million could alternatively
be allocated to other MSDGC or statewide prioritized pollu-
tion control projects.
The financing feasibility of other key elements (non-
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 next in line be-
hind the conveyance tunnels. The approximately $16.7 million
required for instream aeration can easily be met from
-xxv-
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FOOTNOTES
1 All cost estimates are based on those presented in the MSDGC's
Facilities Planning Study (January 1975) 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 $3030.6 million differs from the $3536.5
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 food control(non-TARP).
-xxvn -
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existing state and MSDGC funding sources. It is very un-
likely, however, that the financing will be available to
increase the treatment levels, efficiencies, and capacities
at all the treatment plants (Northside, Calumet, and West-
Southwest) . The total required financing ($1.17 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 time-
frame. The financing feasibility of the Northside and
Calumet treatment plant expansions, however, is reasonable
in view of their combined total estimated costs of $505.1
million. The Federal funding portion ($378.8 million)
could be provided from the additional $780 million PL 92-500
appropriation expected over the next six years. The MSDGC
portion ($126.3 million) could be provided from the antici-
pated $200-400 million additional bonding authorization.^
In terms of the West-Southwest treatment plant expansion
project (estimated cost of $666.3 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.
Funding for the reservoir and flood control tunnels is
currently nonexistent; in addition, there is no reasonable
expectation that any significant financing will be forth-
coming in the near future. A determination at the Washington
level concerning the role of the Corps of Engineers in urban
drainage improvement has not been made. In view of the com-
plexity of this issue, it is very unlikely that Federal funds
for the reservoirs and flood control tunnels will be avail-
able in the near future.
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 $.0541 (for operations and maintenance)
and $.0532 (for tunnel construction) by the year 1986. The
However, to provide the $126.3 million, the MSDGC1s additional
bonding authorization must be at least $216.5 million.
-------
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 Section?;
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 tunnel systems. To assess the significance of
this improvement the EIS considers the possible and likely
cumulative effects of other components of TARP which are not
directly the subject of this EIS. These other components
are the reservoirs, treatment plant improvements, and iristream
aeration. The environmental effects associated with these
components were not otherwise assessed in this EIS.
The principal findings of the EIS are presented under
the following subsections:
(1) Effects of Operation on Water Quality
(2) Effects of a Significant Earthquake on Tunnel
System
(3) Effects of Shale Deterioration on Tunnel Stability
(4) Effects of Rock Spoil Generated During Construction
(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 Construction on Employment.
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(1) 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 ATTAIN-
ING APPLICABLE ILLINOIS WATER QUALITY STANDARDS, AND,
THEREFORE, WILL NOT ENABLE ADDITIONAL USES OF THE
AFFECTED WATERWAYS. ALTHOUGH THE TUNNELS ALONE WILL
NOT RESULT IN ATTAINING THESE STANDARDS, OPERATION
OF THE TUNNELS WITHOUT OTHER POLLUTION CONTROL MEA-
SURES FOR WHICH FUNDING IS UNCERTAIN WILL ENABLE
POLLUTION CONTROL GOALS TO BE AT LEAST PARTIALLY
ACHIEVED.
This conclusion is based on the following findings:
The tunnels will capture approximately 75 per-
cent of the pollutant load now discharged during
combined-sewer overflows and will reduce the fre-
quency of overflows from 100 to 10 times per year.
1977 Illinois water quality standards will con-
tinue to be violated during overflow events be-
cause of uncontrolled injections of pollutants
into the waterways.
The tunnels may not result in the attainment of
1977 Illinois standards for ammonia and possibly
for phosphorus (effluent standards) over lengthy
reaches of waterway, because high concentrations
of these two pollutants are discharged from local
wastewater treatment plants. Although data is
not presently available to allow a more definitive
determination of effects on this point, the at-
tainment 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.
Conditions along the Des Plaines River system
have not yet been modeled by the MSDGC, but will
be completed under the Section 208 planning
program.
-xxxi-
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Implementation of the reservoirs in addition
to the TARP tunnel systems will effectively
eliminate combined-sewer overflows to surface
waterways, thus averting violations of water
quality standards due to wet weather condi-
tions. However, the combination of tunnels
and reservoirs will still not enable attain-
ment of the 1977 DO standard over roughly 40
of the 80 miles of waterways during the late
summer months.
Implementation of the tunnels and reservoirs
in conjunction with upgrading of treatment
plants is projected to have a beneficial
effect on DO concentrations, but the combin-
ation will still fail to meet 1977 Illinois
standards along approximately 24 of the 80
miles of waterways modeled. The time period
will be the same as previously stated.
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 conditions, assuming implementation of
the following pollution control components:
Tunnels
Reservoirs
Treatment plant improvements
Instream aeration.
The water quality impact of these various
pollution control options is summarized in
Table IV-1.
Given current projections of Federal, State,
and MSDGC financing capabilities and policies,
the financing of the tunnels and instream
aeration appears secure. The financing of the
Calumet and North-Side treatment plant expan-
sions is probable; but financing the costly
West-Southwest treatment plant is very doubt-
ful. The financing of the reservoirs in the
near future is very unlikely given the absence
of any Federal commitment to provide assist-
ance .
Additional details on water quality are provided in
Sections 2.1 and 8.1 of the EIS text and details on
financing in Section 3.3.1.
-XXX11-
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(2) 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 SIGNIFICANT DAMAGE TO PORTIONS OF THE TUNNEL
SYSTEM.
This conclusion is based on the following findings:
The 175-year historical earthquake records
indicate that a seismic event with a Modified
Mercalli Intensity (MMI) of VIII can recur
in the Chicago area at a rate of about once per
100 years. Assuming the tunnel system is in operi
tion 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 tun.n>
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 nature 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 founu
in Sections 2.2.3, 2.2.4, and 8.2.2 of the EIS.
(3) Effects of Shale Deterioration on Tunnel Stability
FOR THOSE SEGMENTS OF THE TUNNEL SYSTEM WHICH
ENTER SHALE FORMATIONS, TARP CONSTRUCTION AND
OPERATION MAY BE AFFECTED BY SHALE DETERIORATION.
This conclusion is based on the following findings:
Certain sections of the TARP tunnel systems will
be aligned within Maquoketa shale. During excava-
tion activities in this rock series, rockfalls and
partings (loosened material) will occur and may
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cause construction delays or safety problems.
Delays can range from several weeks to several
months and are costly in terms of labor, equip-
ment, injuries, and lost time. The $30 million
(1972 base) contingency fund established in the
TARP budget is expected to be sufficient to
cover the costs of delays.
Concrete lining is expected to deter, but not
fully to eliminate, shale deterioration. Most
of the TARP tunnel systems will be concrete-
lined and located in Silurian dolomite rock.
Short lengths of conveyance tunnel, however,
will be in shale formations, and deteriora-
tion (i.e., erosion) will occur over a long
period of time as a result of water seepage
or exfiltration. If deterioration becomes
extensive, additional stress will be placed
on the lining, and it may cause fracturing
or cracking of the lining.
Sections 6.2.2, 8.2.2, and 10.1.2 (2) provides
additional information on the subject matter of this
finding.
[4) Effects of Rock Spoil Generated During Construction
THE ROCK SPOIL MATERIAL GENERATED DURING TUNNEL
CONSTRUCTION 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 4,540,000 cubic yards (bulk measure) of
spoil will be removed from the Mainstream Tunnel in the
59th Street to Addison Street segment, which is approxi-
mately 53 percent of the total removed from the entire
Mainstream Tunnel system. Although this amount can be
adequately contained within the inactive Stearns quarry,
the large quantities of spoil involved in reservoir ex-
cavation could complicate disposal plans for tunnel spoil.
Disposal of rock spoil from the reservoirs was addressed
briefly in Section 6.2.4 of the EIS. A significant portion
of rock spoil generated by reservoir construction is likely
to be marketable and to be stockpiled on the quarry site
for eventual sale by the quarry owners.
xx::v
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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.
Landfill disposal sites capable of accepting
the entire volume of tunnel spoil to be gener-
ated during TARP Phase I have not yet been
identified by the MSDGC.
The inactive Stearns quarry has enough volu-ne to
accept the entire quantity of spoil to be exca-
vated from the Mainstream Tunnel 59th Street tc
Addison Street segment (53 percent of total Main-
stream Tunnel system).
Since conventional methods will be used to
excavate rock from the McCook and Thornton
quarries for reservoir construction, it is
likely that a significant portion of the
spoil will be marketable. Present plans en-
vision stockpiling the saleable portion on
the quarry sites for eventual sale by the
quarry owners. Various stockpile configura-
tions are being considered. Nonsaleable spoil
will be stockpiled either on-site, as is pro-
posed for the McCook quarry site, or at an
off-site location owned by the MSDGC, as is
proposed for the Thornton quarry material.
A more detailed discussion is provided in Section
6.2.4 of the EIS.
(5) General Effects of Construction
CONSTRUCTION OF THE TARP TUNNEL SYSTEMS WILL
RESULT IN TEMPORARY PUBLIC ANNOYANCE AND INCON-
VENIENCE FROM THE CUMULATIVE EFFECTS OF NOISE,
HANDLING OF CONSTRUCTION DEBRIS, VIBRATION
FROM BLASTING, DISRUPTION OF VEHICULAR AND
PEDESTRIAN TRAFFIC, AND GLARE FROM THE ILLUM-
INATION OF CONSTRUCTION AREAS AT NIGHT. AL-
THOUGH THE CUMULATIVE EFFECTS MAY BE NOTICE-
ABLE, TAKEN SINGLY, EACH EFFECT IS MINOR.
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This conclusion is supported by the following find-
ings :
Surface construction sites are located in
areas which are generally either vacant or
near low-utilized industrial land.
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 three to nine
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,1
GROUNDWATER INFILTRATION DURING CONSTRUCTION
AND WASTEWATER EXFILTRATION 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 approximately 0.5 MGD per mile of tunnel.
In the absence of appropriate mitigative mea-
sures, this rate is sufficient to lower the
piezometric or hydraulic pressure level of
the upper aquifer. Tunnel grouting is the
most effective method to reduce infiltration
and a grouting program has been incorporated
in TARP. Grouting integrity, however, must
be maintained to keep inflows below the allow-
able limit of 500 gallons per day per inch of
tunnel diameter per mile of tunnel. Obser-
vation wells will be required to monitor
integrity throughout the operational phase
of the tunnel.
The objective of grouting is to achieve maximum penetration and a
uniform qront ',pread. If qroutinq is ineffective, rmvinn-
LI dt-iun/c-XL iltration tiows, wj.li result.
-XXXVll-
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Exfiltration will most likely occur when turi-
nel pressures exceed inflow pressures during
high storm runoff conditions. The TARP grout-
ing program is expected to prevent extensive
exfiltration of tunnel wastewaters into the
upper aquifer. However, if grouting integri-
ty 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 neces-
sary to determine whether exfiltration is
occurring along the tunnel routes.
EIS Sections 2.1.2, 6.1.2, and 8.1.2 provide more
information on the subject of groundwater infiltration
and wastewater exfiltration. Specifications for obser- t
vation well spacing and for the monitoring program are
also presented 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 Main-
stream Tunnel system construction may result
in 90 disabling injuries and in one permanent
disability or fatality. For construction of
the entire tunnel system, injuries and fata-
lities are expected to increase proportion-
ately.
Based on the safety statistics of the current
construction of a rapid-transit system subway
in Washington, D.C., construction of the en-
tire TARP tunnel system could result in 1,829
injuries and in 11 fatalities.
-xxxvui-
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Analysis of the geologic and seismic charac-
teristics of the project area indicates that
most of the area is stable and suitable for
the construction 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 Sections 6.2.2 and 7.1.2.
(8) Effects of Operation on Land Use
THE QUALITY OF LAND IN CERTAIN RIVERBANK SECTIONS
ALONG THE 59TH-TO-ADDISON MAINSTREAM TUNNEL ROUTE
MAY BE ENHANCED BY REDUCED FLOODING CONDITIONS.
Vacant land exists between the North Branch-Chicago
River and North Leavitt Street (bounded by West Oakdale
Avenue on the north and North Hayne Avenue on the south)
in a residential area. The reduction of flooding in
this area will enable development of this under-utilized
land into such uses as: parks, single and multifamily
residences, apartments, and commercial establishments.
If the land is developed into either multifamily resi-
dences, apartments, or commercial establishments, as-
sessed valuation of land will increase and, thus, taxa-
tion increases.
(9) Effects of Construction on Employment
CONSTRUCTION OF THE MAINSTREAM TUNNEL WILL PROVIDE
OVER $87 MILLION IN CONSTRUCTION INCOME OVER A
SEVEN-YEAR PERIOD AND WILL CREATE A PEAK SUPPLY OF
APPROXIMATELY 800 JOBS OVER A THREE-YEAR PERIOD.
Further information may be found in Section 7.1.3.
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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 Mainstream Tunnel system will
significantly reduce the pollutant load in the Chicago water-
ways. These loadings will be reduced further with the im-
plementation of the Calumet and lower Des Plaines Tunnel
systems. Water quality will be enhanced further with the
upgrading of MSDGC's treatment facilities and the construc-
tion of the flood control aspects of the Tunnel and Reservoir
Plan.
2. 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 opera-
tion of the system.
3. Rock falls and partings may occur particularly in
shale formations during construction. Stabilizing measures
such as rock bolting are proposed to mitigate the short-term
construction problems, while concrete lining will be utilized
for the long term. Even with these measures, shale deterior-
ation will continue and the inspection program should take
these sensitive areas into account.
4. 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
environmentally 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.
5. 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.
XXXX
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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. An adequate number of wells are already
in existence for the Mainstream Tunnel system. 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 discussed
particular aspects of the monitoring program.
6. Since the majority of the construction shafts and
drop shafts are in close proximity to area waterways, run-
off 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.
7. 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 these dewatering flows be discharged to
MSDGC's intercepting system for treatment.
8. Although no known historic, architectural, or arch-
aeological resources will be affected by the proposed project,
the possibility of finding archaeological resources must be
investigated by the MSDGC. This must be accomplished by con-
tacting the State Historic Preservation Officer.
9. Conformance with applicable regulation of the Occu-
pational 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.
10. A conflict exists between the location of several
drop shafts and the plans for the Central Area Transit Project,
The MSDGC must meet with the Chicago Urban Transportation
District to resolve these conflicts.
11. There exists a wide range of potential adverse im-
pacts 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 dis-
cussed in Chapter X.
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