EIS-75-3833D
                             METROPOLITAN SANITARY DISTRICT
                                           OF
                                     GREATER CHICAGO
INlXf AJf AC
                             ENVIRONMEINl     ACT STATEMENT
                                         Prepared by:
                               US ENVIRONMENTAL PROTECTION AGENCY
                                          REGION V
                                         Chicago, Illinois

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        DRAFT ENVIRONMENTAL IMPACT STATEMENT

                     FOR THE

 METROPOLITAN SANITARY DISTRICT OF GREATER CHICAGO

       DES PLAINES - O'HARE CONVEYANCE SYSTEM
                  PREPARED BY

THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                   REGION V

                CHICAGO, ILLINOIS
                 MARCH, 1975
                 yntal Pr-rtoctJ.cn
         230 £_v..
         C .r« '"•'.""-.,

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fi-ivf IT* 1 T

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SUMMARY SHEET

1.  Name of Action (Check one)

    Administrative action (X)
    Legislative action    ( )

2.  Brief description of action indicating what states (and counties) are
    particularly affected.
         The proposed projects consist of a system of conveyance tunnels

    known as Upper Des Plaines Intercepting Sewers 20, 20A, 20B, 20C and

    21, and drop shafts to intercept and convey wastewater from a 58.2

    sq. mile service area in the Northwest region of the Metropolitan

    Sanitary District of Greater Chicago to the proposed O'Hare Water

    Reclamation Plant.  (A separate EIS has been prepared on the O'Hare

    Water Reclamation Plant).  Upper Des Plaines Intercepting Sewers 20,

    20A, and 21 will also intercept and convey flows from combined sewer

    outfalls presently discharging to Weller's Creek and Feehanville Ditch

    and will provide partial storage of the combined wastewater for later

    treatment at the proposed O'Hare Water Reclamation Plant.

         The O'Hare MSDGC service area consists of all or part of the

    following communities within Cook County:  Arlington Heights, Buffalo

    Grove, Des Plaines, Elk Grove, Mount Prospect, Prospect Heights, Rolling

    Meadows, and Wheeling, Illinois.

3.  Summary of Environmental Impact and adverse environmental effects.

    A.  Short Term Impacts

        1)  Construction

            a)  Blasting

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         Construction of the drop shaft access manholes and




         parts of some tunnels will require blasting.  To




         minimize the impacts of bias ting particle velocities




         will be restricted by matting and explosive charge




         selection to values that prevent any physical damage




         to surface structures and appropriate screening




         of dust particles will be required.




b)  Noise and Vibration




    1)   Blasting operations will be restricted to certain




         hours of the day.




    2)   Heavy machinery, trucks, and other vehicles will




         increase ambient noise levels in residential areas.




c)  Water Quality and Quantity




    1)   Dewatering of tunnels will temporarily lower the




         water table of the shallow aquifer.  No effect on




         local wells is anticipated.




    2)   Increased siltation in Higgins Creek may occur with




         dewatering of the  tunnels.  (Presently, a half hour




         detention time is  being planned to minimize this




         effect).




d)  Air Quality




    1)   Dust  from construction activities  at surface sites




         will  be minimized  by  using hard paved  surfaces and




         dust  control measures.
                             ii

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            2)   Operation  of  heavy  construction  equipment  powered




                by  internal combustion  engines will  add  to the  air




                pollutant  loading.   However,  it  is not anticipated




                that this  would result  in a significant  temporary




                change in  ambient air quality.




    2)   Operation Impacts




             All conveyance  tunnels will be grouted  and  lined with




        concrete to minimize  infiltration.  In  general,  some slight




        positive infiltration into the  tunnels  is planned  to prevent




        possible degradation  of the groundwater supplies from exfil-




        tration of combined  sewage into the groundwater  aquifers.




             Based on analyses of storms of record,  groundwater levels




        and design parameters, occasional exfiltration into the ground-




        water aquifers might  occur.  A  groundwater well  monitoring




        program is planned to discover  any problems  which  may develop.




B.  Long Term Impacts




    1)   Combined sewage overflows to Weller's Creek  and  Feehanville




        Ditch will be reduced from approximately 80  to 6 flows  a year.




        This would result  in a 92% BOD  reduction and 75% flow reduction




        in combined sewage waste overflows to Weller's Creek and




        Feehanville Ditch.




    2)   Relief of existing interceptors (which are presently overloaded




        during wet weather)  will also be provided.




    3)   No adverse long term impacts are anticipated.
                                     iii

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4.  Alternatives Considered:

    a)  Separation of combined sewers and construction of

        conventional interceptors.

    b)  Collection and conveyance of combined overflows.

    c)  Collection,, conveyance and storage of combined overflows.

5.  Irreversible and Irretrievable Commitment of Resources

    a)  Labor and energy expended in construction of the

        proposed facilities and,

    b)  Capital cost of tunnels is not recoverable.

6.  The following Federal,State and local agencies are being requested to

    comment on this Draft Environmental Impact Statement:

         Council on Environmental Quality
         Department of Agriculture
              Soil Conservation Service
         U.S. Army Corps of Engineers
              North Central Division
              Chicago District
         Department of Health, Education and Welfare
         Department of Housing and Urban Development
         Department of the Interior
              Bureau of Outdoor Recreation
              Fish and Wildlife Service
              Geological Survey
         Department of Transportation
              Federal Aviation Administration
         Energy Research and Development Administration
              Argonne National Laboratory

         Governor of Illinois
         Illinois Institute for Environmental Quality
         Illinois Environmental Protection Agency
         Illinois Division of Waterways
         Illinois Department of Conservation
         Illinois Department of Public Health

         Northeastern Illinois Planning Commission
         Cook County Department of Environmental Control
                                          IV

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         Metropolitan Sanitary District of Greater Chicago

         City of Des Plaines
         Village of Elk Grove
         Village of Arlington Heights
         Village of Mount Prospect
         Village of Palatine
         Village of Wheeling

         Others

7.  Date Draft made available to:

    a)  Council on Environmental Quality - March, 1975

    b)  Public - March, 1975

Acknowledgement

         Portions of this Environmental Impact Statement were taken directly

    from  the Environment Assessment prepared by the MSDGC (November, 1974),

    and the'Tacilities Planning Study - MDSGC Overview Report" and"o'Hare

    Facility Area" (January, 1975) also prepared by the MSDGC.

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                           TABLE OF CONTENTS



Summary Sheet 	    i

Acknowledgement 	    v

1.  BACKGROUND	1-1
    A.  Identification of Grant Applicants  	  1-1
    B.  Description of the Proposed Actions 	  1-1
    C.  General and Specific Location of the Proposed Actions .  .  1-2
    D.  Water Quality and Quantity Problems 	  1-3
    E.  Other Water Quality and Quantity Objectives 	  1-0
    F.  Costs and Financing	1-12
    G.  History of the Application	1-12

2.  THE ENVIRONMENT WITHOUT THE PROPOSED ACTION 	  2-1
    A.  General	2-1
    B.  Detailed Description  	  2-3

3.  ALTERNATIVES	3-1
    A.  Project Objectives  	  3-1
    B.  Constraints	3-1
    C.  Chronology of Plans and Studies	3-3
    D.  Alternatives	3-4
    E.  Comparative Analysis of Alternatives  	  3-6
    F.  Final Systems Screening 	  3-7

4.  DESCRIPTION OF THE PROPOSED ACTIONS 	  4-1
    A.  Main Tunnel	4-1
    B.  Branch Tunnel	4-1
    C.  Sequencing of Tunnel Construction 	  4-2
    D.  Main Shaft and Drop Shafts	4-5
    E.  Access Manholes	4-9
    F.  Relationships to Existing Facilities and Other Projects .  4-9

5.  ENVIRONMENTAL EFFECTS OF THE PROPOSED ACTIONS  	  5-1
    A.  Bedrock Geology	5-1
    B.  Soils and Surficial Geology 	  5-6
    C.  Hydrology	5-7
    D.  Land	5-16
    E.  Air Quality	 5-17
    F.  Biology	5-19
    G.  Environmentally  Sensitive Areas 	 5-19
    H.  Aesthetics	5-19

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                          TABLE OF CONTENTS
                                 -2-
    I.  Noise and Vibration	5-20
    J.  No Action Alternative	5-20
    K.  Summary	5-21
    L.  Findings	5-22

6.  FEDERAL/STATE AGENCY COMMENTS AND PUBLIC PARTICIPATION  .  .   6-1

7.  SELECTED REFERENCES 	   7-1

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                                CHAPTER 1

                                BACKGROUND



A.  Identification of Grant Applicant and Planners

         The grant applicant for the proposed conveyance system projects

    is the Metropolitan Sanitary District of Greater Chicago.  The fa-

    cilities Planning Report for the Metropolitan Sanitary District of

    Greater Chicago is comprised of eight separate reports.  These reports

    consist of an overview report and individual reports for the seven

    facility areas.

B.  Description of the Proposed Actions

         The Upper Des Plaines tunnel conveyance system consists of four

    major elements.  These are:  the tunnels, eight drop shafts and one

    main shaft, seventy access manholes, and nine monitoring wells.  These

    elements will be constructed as five separate projects.  A brief

    description of each is given below.

    1.  Connections and laterals:  Weller's Creek, various locations,
        Upper Des Plaines 20A (73-318-2S).

        This project consists of constructing 22,000 linear feet of 20

        foot diameter tunnel in rock at a depth of 160 feet; five drop

        shafts; one main construction shaft, access manholes and mis-

        cellaneous and appurtenant construction.

    2.  Connections and laterals:  Weller's Creek, various locations, Upper
        Des Plaines 20A (73-318-2S).

        This project consists of constructing special diversion structures

        to control and direct flow from existing interceptors and local

                                     1-1

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        combined  sewer  outfalls  to  the drops  shafts  and/or  tunnels.

    3.   Earth  tunnel:   Waller's  Creek, Mt. Prospect  Road, Princeton
        Street and Wolf Road, Upper  Des  Plaines  20B  (73--319-2S).

        This project  consists of constructing 6,000  linear  feet of  five-

        foot diameter earth  tunnel  at a  depth of 60  feet; together with

        manholes  and  connecting  structures.   This sewer will  divert

        sanitary  sewage flows in the Upper Des Plaines  14A  system from

        the North Side  Plant to  the proposed  O'Hare  Water Reclamation

        Plant.

    4.   Rock  tunnels  and drop shafts:  Weller's  Creek and Feehanville
        Ditch, Lonnquist Boulevard  and William Street, Upper Des  Plaines
        21 (73-320-2S).

        This  project  consists of constructing 11,200 linear feet  of

        16-foot diameter deep rock  level tunnel, 2,000  linear feet  of

        nine  foot diameter deep  rock level  tunnel, three  drop shafts,

        special diversion structures,  access  manholes and miscellaneous

        and appurtenant construction.

    5.   Intercepting sewer:   Upper  Des  Plaines 20C (69-307-2S).

        This  project consists of a  five  foot  diameter interceptor from a

        junction  structure at Wildwood  Road  and  Oakton  Street East along

        Oakton Street for approximately  11,000 linear feet  at a depth

        of 40 feet terminating  at drop  shaft  seven of the Upper Des Plaines

        tunnel conveyance system.  The  sanitary  sewage  will flow to the

        proposed O'Hare Water Reclamation Plant  for treatment.

C.  General and Specific Location of the Proposed Actions

         The Upper Des  Plaines  Basin covers  an area of  58.2 square miles

                                    1-2

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(37,250 acres) in the northwest portion of the Metropolitan Sanitary




District, shown in Figures 1-1 and 1-2.  This area is predominantly




residential in character.  Growth of the area has been spurred by




several factors.  Among the more significant of these is the proximity




of O'Hare Airport, the Northwest Tollway, the Tri-State Tollway, and




the Chicago and Northwestern Railway's tracks which bisect the basin




in a northwesterly direction.




     The area includes the communities of Arlington Heights, Mount




Prospect, Prospect Heights, Wheeling, and a part of the City of Des




Plaines as well as newer urban developments such as Elk Grove Village,




Rolling Meadows and Buffalo Grove.  As illustrated in Figure 1-1, the




boundaries encompass an area which lies generally West of the Des




Plaines River.  Several major drainage courses traverse the basin in




a genera]ly East-West direction and empty into the Des Plaines River.




Two of the waterways are of concern, since they receive combined sewer




overflows even during low intensity storms.  They are Waller's Creek




and Feehanville Ditch.  No other waterways within the Upper Des Plaines




River Basin receive combined overflows.




Water Quality and Water Quantity Problems in the Area




     1.  Sources of Water Supply in the Service Area




         There are three water supply  sources  to the service area:




              a.  Groundwater from shallow glacial-till Silurian




                  aquifer.  The well records indicate  that  the majority




                  of wells in the shallow aquifer are  private domestic




                  service with pumpout rates between 5  to 50 gpm.




                              1-3

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                           "L.J.    \
                        CUPPER DES PLAINES
                        DRAINAGE BASIN1
U=ii   !^",.rHf" I--/*.	  I   vr^?%thes.
 fi^^raES^H -  "• j  jJ^O^^^C^
  - --LJ^S   *,!^^:M::»r:i—t:i.. »-i
                        FIGURE 1-1
         METROPOLITAN SANITARY DISTRICT OF
       GREATER CHICAGO  GENERAL SERVICE AREA
                         1-4

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1-5
                         FIGURE X-2

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                b.   Groundwater  from  the deeper Cambrian-Ordivician




                     aquifer.  The pumpage  rate in  the  region of  the




                     project has  reportedly exceeded  the  sustained yield




                     of  the Cambrian-Ordivician aquifer which has resulted




                     in  a decline of the piezometric  head averaging about




                     10-15 feet/year in the project area.   The municipal




                     and industrial pumpage appears to  be from the deep




                     aquifer which estimated  on population,  may have




                     amounted  to  20 to 25 MGD for  1970  in the project area.




                 c.   Surface water from Lake  Michigan.   It is anticipated




                     that larger  quantises of Lake Michigan water will




                     be  made available to municipalities  outside  of




                     Chicago in  the future  to limit the pumpage  rates to




                     the practical sustained  yield in the project area.




                     Des Plaines  presently  obtains 70 percent of  its




                     water from  Lake Michigan through the City  of Chicago




                     System.




     For a more detailed discussion  of water  supply issues, see  REGIONAL




WATER SUPPLY REPORT //8,  Northeastern  Illinois Planning Commission,




September, 1974.




         2.  Sanitary and Combined Sewers




                  Approximately 5,000 acres of the 37,250 acres in the




             Upper  Des Plaines Basin are expected to remain undeveloped




             and unsewered.   This 5,000 acre  area consists of special
                                     1-6

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use land such as the Ned Brown Forest Preserve, cemeteries




and the U. S. Military Reservations.  Of the remaining




32,250 acres, 26,298 acres are presently (or will be in




the near future) serviced by separate sanitary and storm




sewers, and 5,952 acres are serviced by combined sewers.




In addition, there are 1,370 acres of separate sewered




areas that connect directly to the combined sewer systems




in such a way that the flows cannot be physically separated




except through extensive and costly construction.  Figure




1-3 illustrates the area contributing combined overflows




to the Upper Des Plaines project.  Those areas indicated




are:  1) the combined sewered area, 2) the separated sewer




area contributing to the project, and 3) the boundaries




of all sewered areas contributing to Weller's Creek and




Feehanville Ditch.  There are about 5,448 acres within the




boundary of the sewered area contributing to Weller's




Creek and Feehanville Ditch that are served by separate




sewer systems.  The storm flows from these areas will




continue to discharge directly into Weller's Creek and




Feehanville Ditch and are not a part of the proposed




project.




     At present all sanitary sewage, and the combined




sewage in the O'Hare Service Area, except for overflows,




is finding its way into Metropolitan Sanitary District




interceptors through regulated control structures, and is




                         1-7

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                                                            W •'  Y   wii\
                                                            tl_,i-Bk—iK,
  f
?•« i
.,.JK*r«$K   : " SEPARATED AREAS


'^JfSiy/V;'      CONTRIBUTING TO SYSTEM


        Illlllllll COMBINED SS:WERED AREA
                                    FIGURE 1-3



                  COMBINED-SEWER SERVICE AREA
                                      1-8

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             diverted  through  existing  interceptors  to  the MSDGC's

             North  Side  Sewage Treatment  Works  for  treatment.

                 During wet weather,  the North Side Sewage  Treatment  Plant

             is  presently  overloaded and  existing  interceptors  are

             approaching capacity.   In  addition there is  frequent dis-

             charge (average:  80 per year)  of  combined  sewage  to Weller's

             Creek  and Feehanville  Ditch  creating  an unsightly, odorous

             condition,  as well as  a potential  health hazard.   This un-

             treated sewage then flows  into the Des  Plaines  River.

             Weller's  Creek serves  as the main  conveyance facility  for

             the discharge from combined  sewers serving the  watershed.

             Backup in the combined sewers is  the  primary cause for

             basement  flooding.  Some homes are affected  in  this manner

             from almost all  rainfalls  in the  watershed.   Combined

             backup will flood approximately 100 basements for the  5-

             to  10-year  storm event.  Street flooding will begin  to appear

             for this  same storm event.

                 Overbank flooding does  not occur until  the 25-30-year

             storm  event occurs.

                 The water quality standards  that determine the  effluent

             parameters  for the proposed  Wastewater Reclamation Plant

             are found in  the WATER POLLUTION REGULATIONS OF ILLINOIS.

E.   Water Quality & Water  Quantity  Objectives  in the Area Other Than
    Solution of  Preceding  Problems

    The following programs are relevant:

         1.  The Federal Water Pollution  Control Act Amendments of  1972

                                    1-9

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    (P.L.  92-500)  require:




         a.   Secondary  treatment  of wastes  for municipal




             sewage  and best  practicable  treatment  for  industrial




             discharges by  July 1, 1977.




         b.   Best  practicable waste  treatment technology  for




             municipal  wastes and best  available  treatment




             for industrial wastes by July  1, 1983.




         c.   All point-sources discharges require a permit




             under the  NPDES  program (National Pollutant




             Discharge  Elimination System).  The  NPDES  permit




             states  the allowable waste loading and flow  volume




             that  can be discharged  to  a receiving stream, lake




             or ocean.




2.  The National Flood  Insurance  Act of 1968 requires the desig-




    nation of flood-prone areas in  the  United States and  partici-




    pation by the appropriate communities and homeowners  to




    qualify for national flood insurance protection.  The flood-




    prone areas in the  O'Hare Service Area  have been determined




    for the 100 year storm event  and these  maps,  except for the




    Arlington Heights quadrangle, are available  from the  North-




    eastern Illinois Planning Commission (NIPC).




3.  The Flood Control Activities  planned by MSDGC for the O'Hare




    Service Area are discussed in Appendix A.




4.  The MSDGC Tunnel and Reservoir Plan  (TARP) for control of




    flood and pollution problems  due to combined sewer discharges





                                  1-10

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in the general service area of the MSDGC is described in




Appendix B.  The U.S. Senate Committe on Public Works




(93rd Congress, 1st session) directed the Army Corps of




Engineers to determine the Federal interest in participating




in the TARP program.  Since the Corps viewed any potential




Federal participation to be a significant Federal action,




they determined that part of their response in determining




Federal interest should be the preparation of an Environ-




mental Impact Statement.  Prior to the issuance of a draft




EIS in November 1973, an Environmental Assessment (EA) on




the TARP program was prepared.  USEPA participated in




discussions during the preparation of that EA and made




suggestions with respect to potential environmental impacts




to be addressed.  A public hearing on the TARP EA was held




July 26, 1973 and discussion was presented relating to the




alternative plans presented.  The O'Hare Service Area, since




it contains some combined sewers, was considered in all




alternative TARP plans.  In some TARP alternatives, the O'Hare




service area was sewered by tunnels only, with wastewater




treatment occurring at the MSD North Side STP or WSW  (Stickney)




STP.  Although  this alternative was considered, it was not




supported in other engineering studies for the O'Hare Service




Area.  These reports support a WRP for the O'Hare Service




Area and are discussed in Appendix C.
                       1-11

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              USEPA  has  determined  that  the O'Hare  Service Area




         can  be  separated  from the  TARP  program with  respect  to




         building the  treatment plant  and  the  conveyance  system  to




         it.   No determination has  been  made with respect to  building




         a combined  sewage overflow reservoir  or interconnecting




         the  proposed  conveyance  system  to the lower  Des  Plaines




         TARP system.




 F.   Costs and Financing




         The  project cost  for the O'Hare conveyance system is approxi-




     mately $36.5 million.  This  estimate  includes  the  cost of all




     physical elements of  tunnels,  interceptors, and  connecting




     structures  together with a 20  percent factor for contingencies.




          Financing  of the conveyance  facilities portion  of the  project




     would be through local and Federal  funds. Twenty-five percent,




     $9.1 million, of the  project would  be financed from  an existing




     $380 million MSDGC bond issue  with  the remaining 75  percent,




     $27.4 million,  from Federal  grants.




G.  History of the Application




          Most MSDGC projects, proposed  for the O'Hare Service Basin




    have been given a priority ranking of 31 by  the Illinois  Environ-




    mental Protection Agency  (IEPA).  The infiltration/inflow analysis




    for the service basin  was transmitted to the  IEPA on January 31, 1974.




    It has since been revised by  the MSDGC and is  under review by the




    IEPA.  An informal review is  also presently  underway by this agency.






                               1-12

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                        CHAPTER 2

          THE ENVIRONMENT WITHOUT THE PROPOSED ACTION

A.  General

     The Upper DesPlaines Area Service Basin,  under the jurisdiction

of the Metropolitan Sanitary District of Greater Chicago (MSDGC),

is located in Northern Cook County, Illinois,  within the Chicago

SMSA (Standard Metropolitan Statistical Area).

     The service area is a 58.2 square mile in the northwest

region of the MSDGC's total jurisdiction of 860 square miles within

the County.

     The service area has experienced rapid population growth

during the last 15 years.  The population for  Northeastern Illinois

increased 12.2% from 1960 to 1970.  The following figures

for communities to be served by the proposed water reclamation

plant (WRP) and tunnel system indicate this growth.

Community                     1960         1970        % change

Arlington Heights             27,878       64,884      132.7
Buffalo Grove                  1,492       11,799      690.8
DesPlaines                    34,886       57,239       64.1
Elk Grove                      6,608       21,866      231
Mount Prospect                18,906       34,995       85.1
Prospect Heights               .  . .       13,333       . . .
Rolling Meadows               10,879       19,178       76.3
Wheeling                       7,169       14,746      105.7

(All figures from U.S. Dept. of Commerce, Bureau of the Census,
publication PC(1)A15-I11.)
                                 2-1

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     Figure 1-2 indicates the service  area  and  location  of  the

communities.  The service area is predominantly residential in

character.  The 1970 population for  the area was 223,000,.   Growth

in the area has been encouraged by several  factors  including the
                                                      1
presence of O'Hare Airport,  Northwest  Tollway,  Tri-State Tollway

and the Northwestern Railroad line.  The area  is 60%  developed  and

construction of light industrial facilities and residential units

(both single family and multi-family)  is ongoing to date.

     The economic condition of the area's population  is  above the

Chicago SMSA median family income of $11,841 and State of  Illinois

Median family income of $10,959.

     1970 census figures indicate the  following Median family incomes:

     Arlington Heights                     $17,034
     Buffalo Grove                         $14,833
     DesPlaines                            $14,056
     Elk Grove Village                     $14,155
     Mount Prospect                        $16,503
     Prospect Heights                      $15,992
     Rolling Meadows                       $13,343
     Wheeling                              $13,398

These figures indicate a healthy economic situation within the service

area.

     Few environmentally sensitive areas are within the  service area.

A small portion of the Cook County Forest Preserve  District's Ned

Brown Preserve of 3,600 acres occupies the western  portion of the

area.  The Forest Preserve District's holdings along  the DesPlaines

River are  located in the eastern portion of the area.
                                  2-2

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B.  Detailed Description




     1.  Climate




     The continental climate of the service area has  relatively  warm




summers and cold winters, with frequent short fluctuations  in




temperature, humidity, cloudiness,  and wind direction.   Temperatures




of 96°F. or greater occur in about  half of the summers  while about




half of the winters may have low extremes of -15°F.   The mean annual




temperature is 49 F.  Precipitation averages 33 inches  per  year,




with about 10% of this occuring as  snow.  Summer rainfall is




unevenly distributed in intense local showers while  precipitation




in the fall, winter, and spring tends to be more uniform over large




areas.  Winds are most commonly from the southwest and  the  northwest,




on an annual basis.  Tornadoes occur in Northern Illinois and are




most prevalent in March, April, May, and June.  Other periodic hazards




include severe thunderstorms, hail, and ice storms.   Fog is Infrequent




in the Chicago area.  Detailed climatological data are  available from




O'Hare International Airport, at the south end of the study area.







2.  Topography




     The service area is 58.2 square miles, sloping  from about 700




feet above sea level at the western boundary to about 625 feet above




sea level at the Des Plaines River, 6 1/2 miles to the  east.
                                 2-3

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Landforms are gently rolling,  with slight  vertical  relief.  Most




of the study area has undergone the transition  from a  region  of




small towns and farm land to an extensive  suburban  area  of  single




family homes, apartments, and  commercial and  industrial  development.







3.  Geology




     The project area is underlain by three geologic systems.




The stratigraphic sequence is  the Quarternary System,  the  Silurian




System and the Ordovician System. (See Figures  2-1  and 2-2).




     The Quarternary System is composed solely  of material from  the




Pleistocene series.  The formations contained within the series  are




the Wadsworth and Wedron.  The main constituents of both are  clayey




silts with sand lenses orginating from glacial  deposits.




     The Silurian System lies  under the Quarternary System and




contains material originating  from the Niagaran and Alexandrian




series.  The Niagaran series contains the  Racine, Waukesha and Joliet




formations.  The Racine and Waukesha formations are composed  of




argillaceous fine grained dolomite while the  Joliet formation is a




lighter gray dolomite.  The Kankakee and Edgewood formations  comprise




the Alexandrian Series.  Dolomite is also  the major portion of these




formations ranging from fine to  shaly in texture.
                                 2-4

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System
QUATERNARY
1 SILURIAN
V
ORDOVICIAN
Series
\ i
/ Pleistocene 3
( l
Niogoron
\
Alexandrian
Cincinnotian
t
Formation/Member

WADSWORTH
MEMBER
WEDRON
FORMATION


RACINE
(0 -300')


(WAUKESHA)
(0-20')
JOLIET
(4O-7O)

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Description

Till and outwosh deposits. Clayey silt with
sand lenses. (Gravel lenses possible but not
probable - described in soils report )
Bouldery till, clayey silt with sand lenses,
grovel, boulders common near base and at
unconformity. (Described in soils report.)
Gray- brown, orgillaceous,hne grained,
thin bedded dolomite containing ivefs
of pure, gray, massive, vuggy, dolomite.
Gray, fine groined, silly dolomite.
(Generally absent in northern area )
Light gray, pure, porous dolomite
Light gray, silty,very fine groined dolomite
Red or greenish gray dolomite and
interbedded shale
Light brown, fine grained dolomite with
prominent wavy cloy partings.
Brown to gray sholey dolomite.
(Cherty near top. Not recognized in
project area )
— Oolite and red shale^GenenjIly ^absent )
Oolite and red shale. (Generally absent)
	 Green to brown fossil iferous mud stone
t>«tf
            FIGURE 2-1
STRATIGRAPHIC SEQUENCE

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        ROCK    TUNNELS
          Surface
                                            EARTH    TUNNELS

                                                  -Surface
                                            TrlUffn^.
  50
               OVERBURDEN^
                             +6O
    ESTIMATED    PREDOMINANTLY

    PIEZOMETRIC

    HEAD UNDER   CLAYS AND SILTS
    MAXIMUM
    SURCHARGED
    CONDITIONS
                                        RANGE OF PREVAILING

                                        GROUND WATER LEVELS

                                        AT TIME OF SUB-SURFACE
                                        INVESTIGATION
                                                             CONC. LINING
                                                                           25
                                                                           50
                                                   PROPOSED 5'
                                                   TUNNELS EARTH
2

\
o
>-
h-

o
o
CO
<
o

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-IOO
                             WAN'KAKEE
                            r-BRAINARD

                            -SHALE
                                                    TOP OF ROCK
          GENERALIZED STRATIGRAPHIC  SECTIONS
                               FIGURE 2-2




                                  2-6
                                                                           75
                                                                           100
                                                                          125
::::::::::::::::::::::::::::::!
::::::::::::::=::::::::::::::4
	 __ .. .,
	 1
ttf
Jtt
3RA
9RH
?
i
VPO/I/
?GE
                                                                           150
                                                                           175
                                                                           200

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     The final system is the Ordovician,  composed  of  the  Cincinnation




series which has two formations;  the NEDA and  Brainard  Shale Red




shale and fossiliferous raudstone  comprise the  majority  of these




formations.




     The above discussion emcorapases approximately the  first eight




hundred feet of earth.  There are two main aquifers contained  in




the above mentioned geologic structures.   They lie in the Silurian




and Ordivician Systems.




     The Silurian aquifer has an  average  depth of  108 to  205 feet.




It is composed mainly of glacial  till material.  The uppermost




material, in the area of access tunnels and work shafts is slightly




more porous than that surrounding the rock tunnel.  The coefficient




of permeability (C ) of the glacial till  is 10~6 to 10~8  cm/sec.




Because of the low C  there will  be no significant release of  water




to the tunnel through seepage. Any seepage that will occur results




from openings primarily in the form of cracks  and  joints  in the  rock.




The location of inflows in this case can easily be located after




excavation, particularly within the machine bored  section of  the  tunnel




and may be appropriatly grouted.   Another source of inflow may occur




during the boring of work shafts  or access tunnels.  The  inflow will




originate from ground water seepage, to the upper  portions of  the
                                 2-7

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shaft and tunnels.  This seepage may also be arrested by the




use of grouting techniques.   Within the formation there exists




sand gravei pockets which hold limited amounts of water.  If




they are encountered by construction, the water may be released




to the tunnel.  These quantities of water appear to be extremely




limited and are not known to be used as potable water supply




sources.




     As an overall view it is anticipated that the drawdown of the




water supply aquifier during operation of the facility will be




virtually zero.  It is expected that grouting will reduce the




groundwater flow into the tunnels to less than 300 gpm over the




total length of tunnels based on the results obtained from previous




projects.  Tunnel lining which is planned, will further reduce




inflows.




     Since the tunneling lies within the glacial till-Silurian




system and concurrently within the Silurian aquifier area, a discussion




of the Ordivician aquifier will be left to the water supply section




of this statement.  Groundwater and surface water recharge of the




aquif ers  will also be addressed in that section.  A more complete




discussion of the bedrock geology can be found in Appendix D.

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4.  Soils




     The soils of the study area have developed  from  glacial  parent




materials, under prairie and transitional (prairie to woodland)




vegetation.  Alluvial soils have developed along stream floodplains.




Most soils generally have fairly slow permeabilities  and high




seasonal water tables, resulting in poor drainage. Despite  the




slow drainage erosion control is desirable to avoid soil loss




and the sedimentation of streams.







5.  Hydrology




     A.  Surface Water




     The study area is located in the drainage basin  of the  DesPlalnes




River.  Several small streams originate in the study  area and flow




eastward to join the DesPlaines River.  The streams and their drainage




basins have been and are being modified as the area develops. Named




tributaries of the project area include:  Buffalo Creek and  Wheeling




Drainage Ditch; McDonald Creek; Weller's Creek and Weller's  Drainage




Ditch; Higgins and Willow Creek; and Feehanville Ditch.  All  of  these




watercourses have a 7-day once in 10-year low flow of zero.   The




natural drainage boundaries for Weller's Creek and Feehanville Ditch




are indicated in Figure 2-3.
                                  2-9

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                         rwoisa^K^
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fef
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TTfT ^ r • ':y;vi"~r; .. ^•••/v ->v
              FIGURE 2-3
   NATURAL DRAINAGE BOUNDARIES
WELLER'S CREEK AND FEEHANVILLE DITCH
                2-10

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     Weller's Creek,  which has a total length of  approximately  6.5




miles, is joined by a number of smaller tributaries and  drains  an




area of approximately 10,780 acres.   Portions of  this stream  have




been relocated,  some areas have been channelized  and other  areas




are in underground conduits.  Modifications of dendritic extremities




have been most extensive as many have been eliminated by developments,




and other portions are underground.   The vast majority of this




drainage basin has been urbanized.




     Feehanville Ditch extends for  approximately  2.5 miles  and




drains an area of approximately 1,990 acres.  This watercourse




and its drainage basin have been substantially modified  by urbani-




zation.  The headwaters of Feehanville Ditch are  underground  as




is a portion north of Maryville Academy, and a large portion  of




the stream has been  channelized.




     Higgins Creek is about five miles in length  and drains




approximately 5,000 acres before joining Willow Creek at a  point




approximately three to three and a  half miles upstream from the




Des Plaines River.  The majority of  the Higgins Creek area is




highly urbanized with some industrial and agricultural uses.




Higgins Creek has been filled, relocated and channelized in




several places.




     The flow rates of Weller's Creek at Golf Road have  been




monitored by the United States Geological Survey.  The rates  of
                                 2-11

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flow are as follows:   two-year flood - 520 cfs;  five-year  flood  -




900 cfs; ten-year flood - 1,200 cfs; 25-year flood - 1,600 cfs;




LOO-year flood - 2,400 cfs.   No data are available for  the smaller




drainage basin of Feehanville Ditch.




     The water quality of Weller's Creek and Feehanville Ditch




has drastically deteriorated with the increasing urbanization of




the respective drainage basins.  Computer model  simulation esti-




mated that during the 21-year period from 1949  to 1969,  effluents




from the combined sewers of  this area have overflowed into the




above streams 1,660 times discharging a total 140,000 acre-feet




of sewage which had contained 146,000,000 pounds of suspended




solids, and created a BOD (Biological Oxygen Demand) of  20,200,000




pounds.




     The United States Geological Survey estimated the 10, 50,




100 and 500-year flow rate of Higgins Creek at Mount Prospect




Road to be 840,1,250, 1,650 and 2,180 cfs respectively.   The




water quality in Higgins Creek is poor and is probably below




State standards.  Existing urban activities contribute polluted




stormwater runoff to the natural flow of Higgins Creek probably




adding  significant quantities of inorganic and organic pollutants.




     The Illinois Environmental Protection Agency sampled




Weller's Creek during 1971.  Table  2-1 compares many parameters
                                  2-12

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               WATER QUALITY DATA OF WELLER'S CREEK*
                   COMPARED TO STATE STANDARDS**
                                   Table 2-1
    Weller's Creek
                                      Unit
State Standards
Water

Temperature (F°)

    Number of Analyses                 10
    Maximum Value                      75
    Minimum Value                      36
    Average Value                      55

Field Dissolved Oxygen (mg/1)

    Number of Analyses                  8
    Maximum Value                     8.5
    Minimum Value                     0.0
    Average Value                     2.9

Turbidity (JTU)

    Number of Analyses                 10
    Maximum Value                     800
    Minimum Value                      17
    Average Value                     102
                                                   The maximum temperature rise
                                                   above natural temperature
                                                   shall not exceed 5°F.
                                                   January 60°F. Maximum
                                                   August  90°F. Maximum
                                                   Not less than 6.0 mg/1 during
                                                   at least 16 hours of any 24
                                                   hour period,nor less than
                                                   5.0 mg/1 at any time.
                                                   Waters shall be free from un-
                                                   natural sludge or bottom
                                                   deposits, floating debris,
                                                   visible oil, odor, unnatural
                                                   plant or alga growth, or un-
                                                   natural odor or turbidity.
                                                   1,000 mg/1
Total Solids (Dissolved) (mg/1)

    Number of Analyses                 10
    Maximum Value                   1,309
    Minimum Value                     234
    Average Value                     701

 *  Water Quality Network,  1971, Summary of Data, Volume 2.
    State of Illinois, Environmental Protection Agency.
**  Illinois Pollution Control Board, Rules and Regulations, Chapter 3,
    Water Pollution.  July 1973.
                                  2-13

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            WATER QUALITY DATA OF WELLER'S CREEK
                COMPARED TO STATE STANDARDS
                                 Table 2-1 (continued)
    Waller's Creek                 Unit

Fecal Streptococcus (per 100 ml)

    Number of Analyses                3
    Maximum Value                37,000
    Minimum Value                   270
    Average Value                15,090

Coliform (per 100 ml)

    Number of Analyses                5
    Maximum Value               700,000
    Minimum Value                13,000
    Average Value               188,600

Chemical Oxygen Demand (mg/1)

    Number of Analyses               10
    Maximum Value                   120
    Minimum Value                    22
    Average Value                    49

Biochemical Oxygen Demand (mg/1)

    Number of Analyses                1
    Maximum Value                     5
    Minimum Value                     5
    Average Value                     5
       State Standards
No State standards
No State standards
No State standards
No State standards
                                  2-14

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     WATER QUALITY DATA OF WELLER'S CREEK
         COMPARED TO STATE STANDARDS
                          Table 2-1 (continued)
Weller's Creek
                                 Unit
          State Standards
    Number of Analyses
    Maximum Value
    Minimum Value
    Average Value

Total Phosphate (mg/1 of

    Number of Analyses
    Maximum Value
    Minimum Value
    Average Value

Ammonia (mg/1 of N)

    Number of Analyses
    Maximum Value
    Minimum Value
    Average Value

Chloride (mg/1)

    Number of Analyses
    Maximum Value
    Minimum Value
    Average Value
                               10
                              8 . 3
                              7.3
                              7 . 7
                               10
                              4.2
                              0 . 3
                              1.7
                                5
                              3.8
                              0.6
                              2.1
                               10
                              395
                               70
                              181
Shall be within the range of
6.5 - 9.0.
Phosphorus as P shall not
exceed 0.05 mg/1.
Shall not exceed 1.5 mg/1
Shall not exceed 500 mg/1
                         2-15

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         WATER QUALITY DATA OF WELLER'S CREEK
             COMPARED TO STATE STANDARDS
                              Table 2-1 (continued)
    Weller's Creek               Unit

Fluoride (mg/1)

    Number of Analyses              7
    Maximum Value                 0.6
    Minimum Value                 0.3
    Average Value                 0.4

Iron (Total) (mg/1)

    Number of Analyses              1
    Maximum Value                 0.1
    Minimum Value                 0.1
    Average Value                 O.I

Phenols (mg/1)

    Number of Analyses              3
    Maximum Value                  70
    Minimum Value                   0
    Average Value                  23

Sulfate (mg/1)

    Number of Analyses             10
    Maximum Value                 215
    Minimum Value                  42
    Average Value                  99

Fecal Coliforms  (per 100 ml)

    Number of Analyses             10
    Maximum Value              80,000
    Minimum Value                 400
    Average Value              18,180
          State Standards
Shall not exceed 1.4 mg/1
Shall not exceed 1.0 mg/1
Shall not exceed 0.1 mg/1
Shall not exceed 500 mg/1
Based on a minimum of 5
samples taken over not more
than a 30 day period, shall
not exceed a geometric mean of
200/lOOml nor shall more than
10% of the samples during any
30-day period, exceed 400/ml.
                               2-16

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of water quality with State standards.   The water  quality  of Waller's




Creek is below State standards for the  following parameters; dis-




solved oxygen, total dissolved solids,  total phosphate,  ammonia,




phenols and fecal coliforms.  The water quality of Feehanville




Ditch probably approaches the same magnitude of degradation as




presently exists in Weller's Creek.






6.   Groundwater Aquifers in the Service Area




     The Silurian bedrocks of the study area are overlain  by 45 to




100 feet of glacial material.  The textural composition  of material,




which is often interbedded, ranges from clay to clayed silt, and




usually contains varying amounts of sand, gravel and boulders.




Waterbearing sand layers are common to  this glacial deposit.




Analysis of drilling data indicates the water tables of  this area




vary from 20 to 25 feet in the summer to around 40 feet  in the  winter.




     The shallow aquifers of this glacial drift are hydraulically




connected with the underlying Silurian rocks.  Groundwater in  the




Silurian and Ordovician rocks occurs in joints, fissures,  solution




cavities and other openings.  The water-yielding openings  are




irregularly distributed both vertically and horizontally.   Available




geohydrologic data indicate that the rocks contain numerous openings




which extend for considerable distances and are interconnected  on




an areal basis.
                                2-17

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     Large quantities of groundwater are withdrawn from wells  in




shallow dolomite aquifers of Silurian and Ordovician age in northern




Illinois.  The Niagaran and Alexandrian Series of  Silurian age yield




moderate to large quantities of groundwatei .




     Most water-yielding openings occur in the upper one-third of  the




shallow dolomite aquifers.  A good relationship exists between glacial




drift and the upper part of the shallow dolomite aquifers.   Highest




yielding wells are found in areas where the glacial drift immediately




overlying the shallow dolomite aquifers is composed of sand and




gravel.




     Probable ranges in yields of shallow dolomite wells can be




estimated from specific-capacity frequency graphs, aquifer thickness




and areal geology maps, and water-level data.  On  the basis of these




data, potential wells of the project area could yield up to 40 to 60




gpm (gallons per minute ).




     Recharge of the upper glacial drift-Silurian  aquifer appears




to occur from local precipitation, but the low permeability of the




overburden soils may be reason to suspect some horizontal movement




from the west.




     The lower Cambrian Ordovician  aquifer reportedly received water




from horizontal movement in recharge areas in North-Central Illinois and




Southern Wisconsin; and vertical leakage through the overlying Maquoketa




formation.   In 1958 this leakage was estimated to  be approximately 11
                                 2-18

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percent of the total water pumped from deep sandstone wells in the




Chicago region.  The vertical leakage through the Maquoketa shale




is generally due to the large differential head between the aquifers




(and locally may be facilitated by faultb in the rock).




     According to Walton (Future Water Declines In Deep Sandstone




Wells in Chicago Region, 111. State Water Survey-Reprint Series




No. 36, 1964) the practical sustained yield of the deep aquifers




in the Chicago region is 60 MGD which is less than the actual pumpage.




It is anticipated that Lake Michigan water may be made available to




municipalities in the future to limit the pumpage rates to the practical




sustained yield in the project area.




     Regionally, the shallow groundwater aquifer system reportedly has




a supply in excess of pumpage and any lowering of the groundwater  elevations




is not anticipated except for seasonal fluctuations and local variations




due to pumpage.




     The pumpage rate and the pumpage subdivided by use over the whole




basin from this aquifer has not been established, but available well




records indicate that the majority of wells in the shallow aquifer are




private domestic service with pumpout rates between 5 to 50 GPM.




Municipal and industrial pumpage appears to be from the deep aquifer




which estimated on population, may have amounted to approximately




20 to 25 MGD for 1970, in the project area.  (Average                      .
                                2-19

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per capita consumption 115gpd)  of  which approximately 3  MGD  (11%)




infiltrated from the shallow Silurian aquifer.




     Regional groundwater quality  and quantity  data for  Cook,  DuPage,




Lake, Mclienry, Kane and Will counties are presented in Appendix  E.




This material is available in Technical Report  #8 - Regional Water




Supply Report, September 1974,  by  the Northeastern Illinois  Planning




Commission.




     In addition, Water Conservation measures are described  In the




above mentioned NIPC Technical Report and are included  in Appendix




F.




     c.  Water Quality Management




     Section 208 of the 1972 Federal Water Pollution Control Amendments




Act of 1972 provides for areawide  planning for waste treatment management




in large urban - industrial areas  of the nation which have severe and




complex water quality problems. The northeastern Illinois counties of




which  the  service area is a part have been identified as having such




water  quality problems.  The Northeastern Illinois Planning Commission




is currently organizing a 208 planning effort with local governmental




units.  With the support of local  governments,  the Governor of Illinois




may designate an areawide waste treatment management planning  area




(208 area) and may designate the Northeastern Illinois Planning




Commission (NIPC) as the official "responsible planning agency" for




208  planning.
                                2-20

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     At this writing,  the following service area  governmental units

have supported through resolution,  the designation of  the  six-county

area snd N1PC as the 208 planning agency:

     Arlington Heights
     Mount Prospect
     DesPlaines
     Cook County
     Buffalo Grove


     MSDGC has prepared a proposal as to their  participation within

the 208 planning process.

     The Northeastern Illinois Planning Commission has also completed

a Regional Wastewater Plan (1971),  which will be  a major component

of the 208 study.

     The Illinois Environmental Protection Agency has  the  responsibility

for Section 303 of the 1972 Amendments whereby  water quality problems

are identified and overall pollution abatement  strategies  are

established for all major river basins in the state.

     d.  Flood hazards

     The flood-prone areas in the O'Hare service  area  have been mapped

for the 100 year recurring flood event.  These  maps are available

in 7.5 minute series (topographic)  from the Northeastern  Illinois

Planning Commission.  Channelization of Higgins Creek  is  part of the

Willow-Higgins Creek Watershed, plan illustrated  in Figure 2-4.  This

plan consists of locating storm reservoirs along  Willow-Higgins Creek

and channelizing various sections to protect against  the  100-year

flood.  A summary of the O'Hare area flood control activities is found


                                   2-21

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O
o
                                                                          FIGURE 2-4
                                               2-22

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In Appendix A.




6.  Biology




     Most of the study area has become urbanized,  with  the  original




prairie vegetation and oak-hickory deciduous  forest  being replaced




by agricultural lands, yards,  parks,  and  urban areas.   Principal




remaining natural areas occur  along the Des Plaines  River and  its




tributary streams, and in the  Ned Brown Forest Preserve.  A variety




of birds and small mammals inhabit the service area. Agricultural




and urban runoff have polluted streams and  affected  the original




compositi.on of  stream plants and animals.   No endangered or rare




species from State and Federal lists are  known to  be present in this




area.




7.  Air Quality




     In order to evaluate the  existing air  quality in  the vicinity  of




the proposed projects, air quality data was gathered from  several  sources.




These included  the Illinois Environmental Protection Agency,  the Cook




County Department of Environmental Control, the City of Chicago Depart-




ment of Environmental Control, and an "Airport Vicinity Air Pollution




Study" conducted by the Energy and Environemntal Systems Division  of




Argonne National Laboratory.
                               2-23

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2.  Particulate Matter


     The greatest amount of data available is the result of particulate


matter sampling.  Data from the Argonne study indicate that for

                                                         O
sampling stations west of O'Hare levels vary from 46 /ig/m  in upwind
conditions to 66 /ig/m  for downwind conditions.  On the other hand,


levels at stations east of O'Hare vary from 112 jug/m^ in upwind


conditions, to 66 /ig/m-5 in downwind conditions.  The increase in


particulate values when winds are from the west suggests that the


airport does make a measurable contribution to the particulate loading


downwind of the airport.


     The primary national ambient air quality standard is an annual average

                       o                                                o
no greater than 75 JJg/m  and a 24-hour maximum no greater than 260/ig/m-1.


Samples taken on airport property show that 100% of the 24-hour values


were 240 yig/m3 or_ less while 100% of the 24-hour samples outside the
airport were 180 yag/m  or less.


     At a Cook County sampling station southeast of O'Hare  (Franklin


Park) the annual mean concentration of particulate matter in 1974 was


74^ig/m3.  At another station northwest of O'Hare (and downwind), the


annual mean concentration for 1974 was 67/ig/m^.  While both of  these


stations met the primary standard for particulate matter, they were

                                                 Q
in violation of  the secondary standard of 60^ig/m->.  Data from a


City of Chicago  sampling station east of O'Hare  (Taft High  School)
                               2-24

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from January, 1966 to December, 1974 shows an average annual mean


concentration of 89 jug/m-*.  Obviously, it is very difficult to draw


any conclusions from this data because of the variability of wind


direction and the effects of surrounding .urea emissions.  It does


appear however, that samples taken close to airport sources generally


violate standards, but that the concentrations of particulate matter


decrease with increasing distance from the airport.


     b.  Nitrogen Oxides


     Because there is even less data available on this pollutant, it


becomes even more difficult to note any significant trends.  National


ambient air quality standards state that, as an annual average,

                                                 Q
photochemical oxidants should not exceed 160 jig/m  nor should they


exceed 0.08 ppm as a one-hour maximum.  While some samples taken during


the Argonne study recorded levels as high as 540 jug/m3 (or 0.262ppm),


the variability in samples was extensive with some readings as low as


2.4yug/m3.  For example, samples taken along the northern perimeter


of the airport range from 220 jag/m  to 540 yug/m  .  Along the eastern

                                                   o            3
perimeter of the airport values ranged from 52 /ig/m  to 187 /ig/m .


Comparisons of samples on airport property and those outside O'Hare


show levels of 209 /ig/m  for the former and 109/ig/m  for the latter.


     Results of samples taken by Cook County show an annual 1974 mean of

       O                          n            o
65 ^ig/m  with a range from 32/ig/m-5 to 110 /ig/m  .  Similar samples


taken by the City of Chicago east of O'Hare (Taft High School)
                                 2-25

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indicate a 1974 annual average of 0.036 ppm.  The Argonne study concluded



that concentrations of NO and NOX were substantially higher in active



mobile source areas of the airport than in the surrounding neighborhood.



The highest N0x readings were obtained at both the gate areas and near



the ends of runways 14R and 14L.  As with particulate matter, it can be



seen that monitoring over a long period of time results in annual averages



which are well within the standards.  However, it is very common that



in certain areas, spot samples will result in readings which greatly



exceed the hourly standard.



     c.  Total Hydrocarbons



     In the case of this pollutant it was found that the background levels



of total hydrocarbons (TCH) were so high that it was not possible, in the



case of the Argonne study, to determine the impact of aircraft emissions



on the air quality in the area.  The maximum standard for a 3-hour period,



which is not to be exceeded more than once a year, is 160 ^ig/m-5  (or 0.24 ppm)



Sampling of the northern perimeter revealed THC levels from  1934 ^ig/m->


            *}                            1             "^
to 2330/ig/mJ with a range from 1700jug/nr to 1950/ig/mj along the eastern



perimeter.  THC levels outside O'Hare in Elk Grove Village  (west of Site #1)

                      o              o
ranged  from 1535 >ig/mj to  2100 /ig/m.  The Argonne study noted that the high



background THC could be largely methane which is relatively  stable in the



atmosphere while the  contributions  coming  from aircraft may  contain a



substantial fraction  of reactive hydrocarbons so  that these  contributions



could be  significant  with  regard to  the production of photochemical smog.
                                2-26

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     The Argonne study indicated that it was highly questionable whether




aircraft emissions would have a detectable effect at ground  level




because of the interference with ground based emissions.   Visual




observations of the exhaust plumes saw thon transported  to ground level




at distances of about one to two miles from the runway end.   The visibility




of the exhaust plumes near the surface within one or two  miles  of the




airport as well as their detectability at flight levels  suggest that  at




least one type of impact of particulate emissions is to  increase the




atmospheric pall in the airport vicinity.




     In general, it appears that air quality in the vicinity of the




project sites is severely degraded because of the proximity  to  O'Hare




airport.  While comprehensive sampling indicates that the standards for




some pollutants are not violated, spot sampling would certainly indicate




a noticeable degradation of the air quality in the area.
                              2-27

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8.   Land Use

     Figure 2-5 indicates  various  land  uses  in the  area  of  the  proposed

interceptor.  The Northern Illinois  Planning Commission  (NIPC)  has

identified by 24 categories,  the acreage  of  actual  land  use as  of

1970.  The NIPC "Landuse 70"  elements by  code number  are:

     1 - Residential - single family
     2 - Residential - multi-family
     3 - Residential - mobile homes
     4 - Manufacturing - except wholesale
     5 - Transportation, Communications,  Utilities
     6 - Railroad right-of-way
     7 - Airports
     8 - Streets
     9 - Trade
    10 - Services - private
    11 - Services - institutional
    12 - Military
    13 - Cemeteries
    14 - Entertainment assembly
    15 - Public buildings
    16 - Public and quasi-public open space
    17 - Mining and excavations
    18 - Vacant, Agriculture, Forest
    19 - Vacant - under development
    20 - Water - exclusing public  open  space
    21 - Warehousing - storage structures
    22 - Shopping centers - including parking
    23 - Hotels, motels, transient lodging
    24 - Parking - independent

The following table indicates the  land  uses  of the quarter-sections

through which the interceptors are proposed:
                             2-28

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  32
    33
$£$$£
••••••y.v_
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NIPC Category //	Land  Use Type	Acreage	

     1                         Residential-Single Family      1430.4 acres
     2                         Residential-Multi Family          82.8
     3                         Residential-Mobile Homes          11.8
     4                         Manufacturing-except wholesale  334.1
     5                         Transportation,  Communications,   55.7
                               Utilities
     6                         Railroad right-of-way             21.2
     8                         Streets                         606.6
     9                         Trade                          123.5
    10                         Services-Private                  6.9
    11                         Services-Institutional          103.9
    16                         Public & quasi-public           171.7
                              open  space
    18                         Vacant-agriculture,  forest     1218.9
    1
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     Air and water quality may be threatened by the trend in land




use changes which include more people,  cars, and construction of homes,




offices, industrial plants and shopping centers.  The availability of




vacant land is not the only criteria for future development.  Several




open space agencies exist within the service area (for example local




Park Districts) which are authorized to acquire lands for park and




recreation purposes.  These agencies contribute to the overall environ-




mental improvement by preserving lands  for recreational and environmental




educational uses.  The trend toward open space preservation should be




included in land use alternatives considered in the various plans




prepared by local agencies.




     Comprehensive planning is the process by which a public planning




agency provides for orderly development of an area and promotes a




desirable environment.  By this process, physical development is




coordinated in accordance with present  and future needs.




     Plans and programs usually include a land use plan, a thoroughfare




plan, a common facilities plan and public improvements program.




Administrative and regulative measures  to control and guide physical




development according to the plans include a zoning ordinance, an




official map and subdivision regulations.




     A land use plan shows the location and extent of lands designated




for various kinds of residential, institutional, commercial, industrial




and public purposes.  Current land use planning within the service area




is being carried on by a variety of governmental units.
                               2-31

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     The "Summary of  Local  Planning Documents in Illinois," prepared by

the State of  Illinois Department  of Transportation  (1973), lists the

following plans:

     Arlington Heights        Comprehensive Village Plan  (revised 1967)
                              Preliminary Planning Report 1968
     DesPlaines               Comprehensive Plan 1971, Zoning Ordinance
                              1971
     Elk Grove Village        Comprehensive Plan, 1967
     Mount Prospect           Comprehensive Plan, 1968
     Rolling  Meadows           Subdivision Control Ordinance (amended 1964)
     Wheeling                 General Development Plan, 1965

     The Cook County  Zoning Board of Appeals is currently preparing a

new zoning map and zoning ordinance.  Additionally, the county has a

traffic safety study  in progress.

9.   Sensivite Areas

     No properties included in or eligible for inclusion  in the National

Register of Historic  Places are in  the  area of the  tunnel system.  No

rare or endangered species, from either State of National lists, are

known to occur in this area.  The major open  space  area is the Ned Brown

Forest Preserve.   It  is important both  as a biological and recreational

resource.  Tunnels will be constructed  under  parkland in  Des Plaines and

Mount Prospect.  About 1.4 acres of  parkland  would  be affected by con-

struction of  the dropshafts and access  manholes.

10.  Population Projections and Economic Forecasts

     The projected population forecast  of  the Northeastern Illinois Planning

Commission (NIPC) is shown in graphical form  in Figure  2-6, and in Table

2-2.  The present population in the O'Hare  Service  Area  is approximately

250,000.  The projected population for  the  design year  of 2000  is  300,000.


                               2-32

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          POPULATION  FORECAST
          O'HARE  FACILITY AREA
450
200
 1970
1980
1990   2000
   YEAR
2010
2020
2030
                 FIGURE 2-6
        POPULATION  FORECASTS
                    2-33

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Table 2-2.  Population forecasts for  the O'Hare  Service  Area.
(Source:  Northeastern Illinois Planning Commission)
        YEAR	Forecast  Population

        1976                          223,000
        1980                          261,000
        1990                          277,000
        2000                          300,000
     Economic forecasts available are limited to  projections of  employment

by townships prepared by NIPC.  The three townships principally  in the

O'Hare Service Area are Elk Grove, Maine and Wheeling.   The employment

forecasts for these townships are shown in Table  2-3.
Table 2-3.  Employment forecasts for the O'Hare Service Area
(Source:  Northeastern Illinois Planning Commission)
Township
Elk Grove
Maine
Wheeling
TOTAL
1970
37,257
52,767
24,916
114,940
1980
43,400
68,600
31,200
143,200
1990
46,300
74,300
34,300
154,900
2000
47,100
75,800
34,700
157,600
11.  Other Programs in the Area

     New federal legislation entitled the "Housing & Community

Development Act of 1974" provides the possibility of -funding for

community development activities.  Within the service area, two
                                 2-34

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communities,  Arlington Heights and DesPlaines have populations  greater




than 50,000 and thus are eligible for their  own "entitlement" moneys.




Cook County would be eligible for funds as an "Urban County" under




tills art.   Sewer construction is one eligible activity under the




program.  Future growth capacity could be stimulated by this federal




program and ultimately serviced by the MSDGC.
                                2-35

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                                 CHAPTER 3




                       CONVEYANCE SYSTEM ALTERNATIVES






A.  Project Objectives




    1.  The elimination of combined sewer overflows into Weller's Creek




        and Feehanville Ditch.




    2.  The conveyance of wastewater generated within the Upper Des Plaines




        Drainage Basin to the proposed Water Reclamation Plant (WRP)




        located in the service area.




    3.  The minimization of the environmental impacts of construction on the




        extensively developed residential areas in the Upper Des Plaines




        Drainage Basin.






B.  Constraints




         There were three principal constraints on the selection and design




    of alternative systems:




    1.  The Weller's Creek and Feehanville Ditch Drainage Basins are




        extensively developed, primarily in residential uses sensitive to




        disruption.




    2.  The 29 outfalls in the study area will be, by December 1977, in




        violation of the Illinois Environmental Protection Agency (IEPA)




        water pollution regulations adopted by the Illinois Pollution Control




        Board in July 1973 and approved by USEPA.




    3.  For the project to be economically feasible, routings between a




        treatment plant and the overflow points should be as direct as




        possible.
                                     3-1

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                                       •L...J.      \
                                   -'UPPER DES PLAINES
                                    DRAINAGE BASIN^
           - ,--.-, ,,.     ...   ,- ..   --•»-
            '  i-j'—..  ,'-.5  ;  ^ (      •
             "!  """r-;    l"-:  l-—-,   *•
          ^aib^-^^?^-^^'11^*""*"****^.^ "^
LEGEND
        M.S.D.G.C. COMBINED-SEWER SERVICE AREA I	"ii,.
                                    FIGURE 3-1
             METROPOLITAN  SANITARY  DISTRICT  OF
         GREATER  CHICAGO  GENERAL SERVICE AREA
                                       3-2

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C.  Chronology of Plans and Studies




        The Metropolitan Sanitary District of Greater Chicago is divided




    into eight service basins.  Of particular interest in this statement




    is the Upper Des Plaines Drainage Basin,delineated in Figure 3-1.




    Collection and treatment of sewage generated in the Upper Des Plaines




    Basin has been the subject of many studies and reports.  Based on a




    report by Greeley and Hansen submitted in 1962, a tentative decision




    was made to convey all sewage from the area to the West-Southwest




    treatment works at Stickney.  Following the Greeley and Hansen 1962




    report, additional studies and investigations, carried out primarily




    because of the trend toward higher standards for disposal of treated




    effluent, have indicated the advisability of collecting and treating




    the sewage from each drainage area separately.  The policy of separa-




    tion of drainage areas has been adopted by the MSDGC and four treatment




    works are planned for the Northwest Area.  The four systems have been




    designated as O'Hare (Upper Des Plaines), Salt Creek, Hanover Park and




    Poplar Creek.




        A preliminary design concept for the O'Hare Water Reclamation Plant,




    and an estimate of cost of both the intercepting sewers and the recla-




    mation facilities was prepared in report form for the MSDGC by Brown and




    Caldwell, Consulting Engineers, dated June 1968.  Preliminary plans for




    the intercepting sewers were prepared by De Leuw, Gather & Company,




    Consulting Engineers, in accordance with an agreement between that firm




    and the MSDGC.
                                   3-3

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D.  Alternatives




         There are three basic alternatives to the wastewater management




    problem within the Upper Des Plaines Drainage Basin.  Given the need to




    provide additional treatment capacity, and the laws governing the dis-




    charge of combined sewage into surface waterways, there are:  1) Sewer




    separation, 2) Conventional interceptors, and 3) Interception and




    conveyance of combined sewage.  Certain of these alternatives can be




    combined; in addition, the basin alternatives themselves have




    sub-alternatives within the context of their own plan.




    1.  Sewer Separation — This alternative consists of the elimination of




        the combined sewer system throughout the Villages of Arlington Heights




        and Mount Prospect, and the City of Des Plaines.






        Detailed engineering and cost analyses have not been made for the




        the Upper Des Plaines Basin for this alternative; however, such analyses




        were made for Palatine, Illinois, a neighboring community of similar




        character.  In the latter instance, two methods were investigated:




        construction of a new sanitary sewer in every street within the




        combined area and conversion  of the existing combined sewer to a




        storm sewer; or, construction of new storm sewers and conversion of




        the existing facility to a sanitary sewer.  In practice, there




        would be some waste in either method, since the existing sewers are




        generally larger than required by sanitary flows, and not large




        enough to accommodate storm flows of the magnitude required to




        eliminate flooding.  Perhaps a more efficient solution may be




        conversion  of the larger existing facilities to storm sewers to




        sanitary sewers.




                                        3-4

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    The alternative would involve construction within every block of




    every street.   Construction within any given block length would




    probably require several weeks,  excluding construction time for the




    replacement of permanent pavement.  Such a program could extend




    over a period  of several years,  depending upon the magnitude of the




    area the municipality chose to impact at one time.






2.  Conventional Intercepting Sewer— Two conventional systems were




    examined:




    a.  A system of conduits which would intercept the existing MSDGC




        intercepting sewers within the Upper Des Plaines Basin and




        direct the sanitary flows to the proposed Water Reclamation




        Plant.  Two subalternatives were developed which differ only




        in alignment.  The least costly scheme would have a total




        project cost of approximately $24.2 million (1972 dollars).




    b.  Conventional intercepting sewers, together with sewer




        separation.






3.  Collection and Conveyance of Combined Overflows — This alternative




    consists of collecting overflows from the existing outfalls, and




    conveying combined sewage to the proposed Water Reclamation Plant




    for treatment  prior to discharge to the waterway.  The system would




    consist of large diameter rock tunnels, together with necessary




    appurtenant structures to connect the existing combined outfalls and




    redirect the combined overflows to the rock tunnel system.
                                 3-5

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    4.  A no action alternative was also considered for purpose of evaluation.

        This alternative consists of simply doing nothing with regard to

        combined sewer overflows into Weller's Creek and Feehanville Ditch

        or diversion of flows to the proposed O'Hare  Water Reclamation

        Plant.  Impacts on water quality of Weller's Creek as a result of no

        action are discussed in Chapters 2 and 5.  All sanitary sewage

        generated within the basin would continue to flow thru interceptors

        to North Side Sewage Treatment Works.


E.  Comparative Analysis of Alternatives

        To evaluate the various options available for wastewater management

    within the Upper Des Plaines Basin, six alternatives were assessed in

    relation to project objectives (See Table 3-1).


	Table 3-1  Comparison of Alternatives and Project Objectives	

                                     	Project Objective	
       Alternative No.
Eliminate   Conveyance   Minimize Environ-
Combined        to       mental Impacts
Overflows     Plant      of Construction
1. Sewer Separation
2A. Conventional
yes
no
no
yes
no
yes
       Interceptors

  2B.  Separation with

  3A.  Collection and
       Conveyance of
       Combined Overflows
  3B.  Collection, Conveyance
       and Storage of Combined
       Overflows

  4.   No Action
* Partial
  yes
 *yes
  yes
  no
yes
yes
yes
                no
                               no
yes
yes
                               yes
                                    3-6

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    Two alternatives—separation with interceptors (Alt.  2B)  and collection,
    conveyance and storage (Alt. 3B)  would meet the first two project
    objectives.  In addition, the collection/conveyance alternative (Alt.  3A)
    would meet the second objective and greatly reduce overflows.  This
    alternative partially meets objective one and would result in a 72 percent
    reduction in total volume of spills, a 93 percent reduction in number of
    spills and a reduction in the number of average yearly spills from
    approximately 80 to six.

        In the selection of alternatives for further screening, only those
    which were at least in part responsive to project objectives were
    carried forward.

F.  Final Systems Screening
        Three alternatives were selected for more detailed analysis.  These
    were:

    *   Separation with interceptors.
    *   Collection and conveyance of combined overflows.
    *   Collection, conveyance and storage of combined overflows.  The
        proposed Water Reclamation Plant is designed to handle peak dry
        weather flows only and not the peak wet weather flows from combined
        sewer areas.  MSDGC plants are normally operated at full capacity
        before and after storms to minimize the overflows of untreated flow.
        It is not cost-effective or feasible to increase the plant peaking
        capacity to match the rate of storm runoff, which for the 11.4
        square mile combined sewer area may reach over 30 times the dry
        weather flow for the entire 58.2 square mile basin.
                                    3-7

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1.  Separation with Interceptors Alternative




        Of the 7,322 acres of combined area in the Upper Des Plaines




    Basin, 1,370 have separate local sewer systems, which are recombined




    at the dowstream end with the combined system, leaving 5,952 acres




    which would require new separated sewer systems.  A detailed




    analysis of Palatine, Illinois indicates that the cost of a new




    separate sanitary sewer system would be approximately $12,700 per




    acre.  For the O'Hare Service Area this results in an estimated




    separation cost of $75.6 million.  In addition, if separation were




    accomplished, conventional interceptors would still need to be




    constructed at an estimated cost of $23.2 million for a total system




    cost of $98.8 million.




        While this alternative would achieve the objective of elimination




    of combined sewer overflows, it would have other severe environmental




    implications.  The amount of surface disturbance necessary would be




    extensive.  Even with considerable construction safeguards, there




    would still be a significant quantity of erosion and runoff due to




    the construction and separation of the sewer systems.  In addition,




    the quantity of material resources necessary for this alternative




    would be significant.






 2.   Collection,  Conveyance and Storage of Combined Overflows  Alternative




         A detailed engineering analysis was  made of tunnel  and reservoir




     alternatives.   A report titled "Preliminary Plans  for O'Hare  Collection




     Facility," dated November 1972,  presents a summary of this analysis




     and tunnel and reservoir concept plans.   The estimate for the preferred
                                   3-8

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tunnel and reservoir scheme selected for the total basin is $88.5

million.  This figure is established from Chapter XI, of the De Leuw,

Gather report by adding the estimated land cost to the estimated

construction cost (including 20 percent for contingencies) and

deducting the $18.8 million estimated cost of the Palatine area

projects.  (Palatine area projects are no longer planned to be

interconnected to the O'Hare tunnel conveyance system).

    It has been estimated that the average yearly volume of combined

sewage intercepted by the tunnels and reservoir would be 6670 acre-feet.

This is equivalent to a runoff of approximately eleven inches over

entire combined sewer area in the basin.  This 6670 acre-feet is

equivalent to a yearly volume of 2.17 billion gallons or 5.95 MGD

average additional flow to the plant.

    The treatment cost for the additional combined over-flows

intercepted by the tunnel and reservoir concept projects may be

estimated as follows:

                               Yearly Cost           Total Cost

    Additional flow due        $155/MG times
    to interception of         365 days/year
    combined sewage            times 5.95 mgd=
    flows 5.95 MGD             $336,621/year
                               times (Present
                               Worth Factor of
                               6%/50 years
                               15.762) =             $5,305,820

Therefore a cost comparison for separation versus a tunnel and

reservoir plan by only $5.0 million, the following factors should be

considered:

    a.  The maintenance and operation cost estimated at $144/MGD is
                              3-9

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            very conservative for combined sewage treatment.   It  is  based




            on the MSDGC surcharge ordinance which relates  to  the treatment




            of sanitary sewage and industrial  wastes.




        b.   The assumption of a 50-year maintenance and operation cost




            is cons erva t ive.




        c.   The cost of inconvenience to the public by excavation in




            every street in the combined sewered area, as would be




            required in the sewer separation alternative, is not  reflected




            in the cost comparison.




        d.   The cost of required replumbing for buildings in  the  combined




            sewered area is not included in the $12,700 per acre  cost used




            for sewer separation.




        e.   The monetary value of pollution reduction by the  treatment of




            polluted urban runoff is not reflected in the cost comparison.






3.   Collection and Conveyance of Combined Overflows Alternative




        The MSDGC has opted not to construct  the reservoir  portion of the




    tunnel and reservoir plan at this time.  Such a decision  results in




    a system of rock tunnels identical in structure to those  of the tunnel




    and reservoir plan.  This option is referred to as the  Rock Tunnel




    Alternative.  All flow characteristics, connections, locations and




    sizes would remain the same as those under the tunnel and reservoir




    plan, but the storage volume would be reduced to that of  the  volume




    of the tunnels.




        The completed Rock Tunnel Alternative system will provide approxi-




    mately 200 acre-feet of storage for combined sewage capture.   This
                                3-10

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is sufficient volume to contain approximately 1/3 inch of runoff




from the entire 7322 - acre combined sewer area.  Using a combined




runoff factor of 45 percent, this is equivalent to the runoff from




a 3/4 inch rainfall over the Upper Des Plaines combined sewer area.




    Computer model studies indicate that approximately 72 percent




of the volume of all combined sewer discharges to Weller's Creek and




Feehanville Ditch would no longer occur on completion of the tunnel




system.  This would reduce the biochemical oxygen demand (BOD) and




suspended solids discharged by approximately 92 percent and 93




percent, respectively.   Cost of a system of collection and conveyance




rock tunnels including all appurtenant structures to provide an




operating facility is estimated to be $36.5 million (1972 present




worth).




    The Rock Tunnel Alternative is described in greater detail in




Chapter 4 and assessed in Chapter 5 for comparative purposes with the




no action alternative.
                              3-11

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                          CHAPTER  4






              DESCRIPTION OF THE PROPOSED ACTION






     The proposed action consists of a network of tunnels and shafts ranging




in diameter from 5 to 20 feet.  A majority of the tunnels (6.63 miles) would




be located approximately 160 feet below the ground surface in rock.   The




remaining 3.22 miles of earth tunnel would be at depths approximately 40 feet




below the surface.  See Figure 4-1.




     This network is designed to collect all combined sewer overflows within




the project area and direct them together with sanitary flows, to the




south end of the tunnel system.  A description of each contract of the proposed




project is given in Chapter 1.  All earth tunnels will be lined with  12 inches




of concrete and all rock tunnels with 10 inches of concrete.




A.  Main Tunnel




     The main rock tunnel would be 20 feet in diameter and run north  along




Elmhurst Road from a main shaft located approximately 400 feet southwest of




the intersection of Elmhurst Road and Northwest Tollway to Drop Shaft 4.  From




Drop Shaft 4 the main tunnel would proceed northwest along Weller's Creek




to Drop Shaft 1 located approximately 400 feet north of the intersection of




Central Road and Weller's Creek.




B.  Branch Tunnels




     The east branch tunnel would be 16 feet in diameter.  It would begin




at a junction with the main rock tunnel at the intersection of Elmhurst Road




and Lonnquist Boulevard, and proceed east in Lonnquist Boulevard to Drop




Shaft 6 at Williams Street, then turn north and follow Williams Street to




Drop Shaft 8 located approximately 200 feet northeast of the intersection
                                   4-1

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 /	1
LEGEND
• ••• ROCK  TUNNEL
        (APPROXIMATELY 1 SO FEET BELOW SURFACE)
Illlllllllll EARTH TUNNEL
        (APPROXIMATELY 60 FEET BELOW SURFACE)
   A   DROP  SHAFT
 SCALE IN MILES
O    1/4    1/2
                                  1 1/7
                                            FIGURE 4-1
                          ROCK TUNNEL ALTERNATIVE
                                               4-2

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of Isabella Street and Rand Road.   A nine-foot rock tunnel would junction




with the east branch at Lonnquist Boulevard and Williams Street, and proceed




east along Weller's Creek to Crop Shaft 5 located at Weller's Creek and




Mt. Prospect Road.




     A five-foot earth tunnel, to be lined with concrete, would begin at




Drop Shaft 5 and proceed north on Mr. Prospect Road to Princeton Street,




then east in Princeton to Wolf Road and north in Wolf Road to intersection




of Rand Road and Wolf Road.




     Beginning at Drop Shaft 7 a five-foot concrete-lined earth tunnel




would extend west under Oakton Street approximately 2.08 miles to the




intersection of Oakton Street and Wildwood Road.




C.  Sequencing of Tunnel Construction




     It is anticipated that construction of the 4 tunnel contracts will




commence on approximately the same date.  The connection and laterals




contract, U.D. 20A  (Contract 73-318-2S) is expected to be awarded approximately




one year later.




     Tunnels are generally excavated in an upgrade direction since this




facilitates dewatering and muck removal.  However, for the rock tunnel




project it is anticipated that spoil removal, specified shaft location and




the magnitude of the projects will be a more  important consideration.




1.  U.D. 20 (Contract 73-317-2S)




     Tunnelling will commence at the main shaft at the southwest corner of




the Northwest Tollway and Elmhurst Road and proceed northerly and westerly




to the site of Drop Shaft No. 1 located at Central Road east of Busse Road
                                 4-3

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2. U.D. 21 (Contract 73-320-2S)




     Tunnelling for the 16 foot  diameter tunnel will commence at the site




of Drop Shaft 8 at Rank Road and Isabella Street and proceed, reverse grade,




southerly and westerly to a junction with U.D.  20 at Elmhurst Road and




Lonnquist Boulevard.




     Tunnelling for the 9 foot diameter tunnel  will commence at the location




of Drop Shaft No. 5 at Mt. Prospect Road and Lonnquist Boulevard extended




and extend westerly to the junction with the 16' diameter tunnel at Lonnquist




Boulevard and Williams Street.




3.  U.D. 20B (Contract 73-319-2S)




     Tunnelling will commence at Lonnquist Boulevard (extended) and Mt.




Prospect Road and proceed northerly and easterly to Wolf and Rand Roads.




4.  U.D. 20C (Contract 69-307-2S)




     Tunnelling will commence at the location of Drop Shaft 7 at Elmhurst




Road and Oakton Street and proceed westerly to Oakton Street and Wildwood




Road.




     The  tunnel water detention basin required for U.D. 20 will be located




immediately west of the main  shaft.  Water infiltrating into the tunnels will




drain  by  gravity to the low point in the tunnel  system at the location  of the




junction with the 7-foot  diameter plant influent tunnel.  From this point it




will be pumped out  through the main shaft to the detention basin which  will




be pumped or drained by gravity to Higgins Creek immediately west of  the




site of the Main shaft.
                                  4-4

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     Excavated material will be removed from the tunnels at main shaft




sites.  Transportation in the tunnels will be by muck cars traveling on




rail tracks laid in the tunnels.  The material will be removed from the




tunnels by a crane or elevator hoisting system.  It will then be deposited




near the shaft at a temporary storage location or hauled immediately




from the site to its ultimate user.  Market conditions and available storage




space will dictate the amount and time of storage.  The MSDGC owns




approximately 112.5 acres adjacent to the main shaft, part of which will




be made available for spoil storage.




     The material excavated will be composed of spalled or laterally split




rock of small dimensions with a large percentage of fines.  As this




material does not have a. gradation conforming to accepted specifications




for concrete aggregate or roadway base material, it is not generally




acceptable for these purposes.  However it has been used in private




developments for such things as stone base for parking lots.  The primary




use of this material is expected to be as land fill.




D.  Main Shaft and Drop Shafts




     The main shaft is the location for lowering and removing the mining




machines.  Men, equipment and material will enter and exit from the tunnel




system from this shaft during construction.  Dewatering during construction




will take place at this location.




     After construction, the main shaft will serve as part of the exit




structure from the tunnel system should a reservoir eventually be constructed




 at its terminus.   The  main  shaft is in fact  located on the proposed site




 for a main reservoir which  was  proposed by DeLeuw,  Gather and Company in




 the preliminary  plans.   After construction the main shaft,  having a finished




                                 4-5

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internal diameter of 16 feet,  will be capable of being used for lowering a

maintenance vehicle into the tunnel system.

     A drop pipe will be provided at the Main Shaft to extend service to

the portion of the service basin area south of the Tollway.


                              Drop Shafts


Shaft Number                       Location

     1                    Approximately 400 feet north of the inter-
                          section of Central Road and Weller's Creek.

     2                    At the intersection of Weller's Creek and
                          Lincoln Street.

     3                    Within the park along Weller's Creek
                          approximately opposite Wa-Pella Avenue.

     4                    At the intersection of Weller's Creek
                          and Elmhurst Road.

     5                    At the intersection of Weller's Creek
                          and Mt. Prospect Road.

     6                    At the intersection of Williams Street
                          and Lonnquist Boulevard.

     7                    At the intersection of Elmhurst Road
                          and Oakton Street.

     8                    Approximately 200 feet northeast of  the
                          intersection of Isabella Street and
                          Rand Road.

     The  shafts  would  require excavation approximately 160 feet  deep  into

 the overburden soils and  rock.  These excavations would  require  temporary

 sheeting  and  bracing to support the  adjacent earth until the permanent

 structures are constructed  and backfill work is completed.  Blasting  would

 be required for  excavation  of the  rock portions.  This blasting  would

 continue  for  approximately  one month at  each shaft and be  limited  to  one

                                   4-6

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blast every two or three days.  During the construction of the shafts




the work areas would be fenced and secured in accordance with MSDGC




standard practices.  The shafts would vary in size from five to nine




feet in Internal diameter.  Construction would proceed from the surface




downward to the tunnel level.




     A sectional view of the Type D-4 drop shaft to be used in the Upper




Des Plaines Tunnel Conveyance System is shown in Figure 4-2.  It is noted




that the air insufflated into the water on its way down the shaft in




the downcomer is released in the separation chamber.  This air rises




in the vent shaft and becomes reinsufflated into the incoming sewage




at the top of the downcomer.  There is, therefore, no net movement




of air out of the drop shafts.  During model studies the vent shaft




openings to the atmosphere at the top of the structures were sealed during




some of the experiments, thereby precluding the possibility of air movement




out of the shafts.  This did not affect operation of the drop shaft.




     While the aspect of aerosol release at the top of the vent shaft or




downcomer was not specifically studied in the model study program, MSDGC




observed that this phenomenon did not appear to be occurring.  In the




event that the prototype drop shaft does operate differently from the




models and the phenomenon of air movement out of the shafts does occur




the openings to the surface of the ground could be sealed without hydraulically




affecting the structures.




     Sluice gates will be placed in collection structures at the location




of all major sources of storm water inflow into the tunnel system.  These




gates will be provided with an alternate power supply or other means to




insure their operation when required.  The gate status will be continuously






                                    4-7

-------
      DROPSHAFT   D-4  TYPE

   UPPER  DES  PLAINES  TUNNEL PLAN
                                  GROUND LEVEL
                              RECIRCULATIN6 AIR
SUMP-
                                 t—AIR SEPARATION CHAMBER
                 •x-^l      *     \

                 *°o I	U[    1	

         '/X?'^>*^re&%<:\ • - ' • I . ° *   • ' •
          ' Ci-Oo o Q o..o;fij=y»Q-^«;y-Tr^"*>vr-'>;—^"—-;
           c ° _O, ;.uo o oo-i,'ct^~tWo—o^B-SL -«r a_,*
         »*OC7Q <^0°* oOos^^yg^gZ	-S±:
          O^. ^ r-K'*- 
-------
monitored (visually and be computer) at the proposed O'Hare Water




Reclamation Plant.  In the proposed tunnel conveyance system the gates




will be closed as necessary during major storm events to prevent filling




of the rock level tunnel system above a level higher than the crown at




the upstream ends of these tunnels.  This will prevent rapid filling of




the drop shafts which might result in hydraulic surges.  In addition by




keeping the rock level tunnels from being surcharged potential backup of




local sewer systems will be prevented.




E.  Access Manholes




     Access manholes would be constructed at approximately 2,000-foot




spacing along the work tunnel alignments.  Under current MSDGC practices




manholes are placed at approximately 600-foot spacing along tunnel




constructed through earth.  These manholes would be constructed from the




surface downward in a manner similar to the drop shafts; however, they




would require a much smaller excavation.  Some blasting would also be




required in the excavation of some of these elements.  Access manholes




would be located within or adjacent to the parkway or shoulder area




of public roadways.  The construction period for an access manhole is




approximately three months.




F.  Relationship of Proposed Action to Existing Facilities and Other Projects.




     The physical relationships between the existing combined sewer systems




and the proposed conveyance system are exhibited in the preliminary plans




for the project.  (Preliminary Plans for O'Hare Collection Facility, November




1972, De Leuw, Gather & Company)
                                  4-9

-------
     These preliminary plans illustrate that under the ultimate plan




(reservoir included) sufficient storage capacity will be available with




the facility to permit plugging the smaller combined sewer overflows.




The larger interceptor outfalls are maintained to serve as safety valves




for the system.  Under the proposed plan, all existing overflows will be




maintained due to limited storage capacity.  The volume of the proposed




conveyance tunnels is approximately 220 acre-feet.




     The existing combined sewer systems have been estimated to be slightly




less than capable of handling a storm of 5-year return frequency.  This




evaluation is a generalization, however, since some subsystems very likely




have a capacity of even less than this.  The proposed tunnel facilities were




planned to provide a flow-through capacity sufficient to handle the




"storm of record" without creating surcharging in the existing combined




sewer system.  The existing systems do not have the capacity to handle




the storm of record volume, and accordingly provisions are made in the




design of the proposed facility for future relief of the existing system




by the local municipalities.




     The total mass discharge  from all combined sewer outfalls within




the project area for the 21 years used in  the study analysis is 140,000




acre-feet.  This arithmetically averages to 1,867 acre-feet per year being




discharged to  the waterways after the  facility is in operation.  These




remaining overflows will continue to occur at the existing outfalls.




     Tunnel maintenance, when  required, must be done by entering the tunnels




and performing the work in accordance  with procedures common within the




industry.  No  techniques or equipment  not  presently available  are expected




to be  required.  In  the event  the tunnels  must be entered, all inflow  and






                                 4-10

-------
control gates must be closed,  and dry weather flow diverted to the North




side plant for processing.   Gates are provided at all inflow points to




the proposed tunnel system.




     The design of the tunnel system of the Upper Des Plaines Tunnel Plan




does not depend on or interact with the design of small, local storm




water retention basins, whether existing or to be constructed by the




Villages of Mount Prospect and Arlington Heights.  The Upper Des Plaines




Tunnel and Reservoir Plan contemplates two reservoirs, the Main or Upper




Des Plaines Storage Reservoir, possibly to be located on a site at the




southwest corner of the Northwest Tollway and Elmhurst Road adjacent to




the Main Shaft, and the Mount Prospect Detention Basin to be constructed




adjacent to Drop Shaft No.  1 at Central Road east of Busse Road.




     It is noted that the Main Reservoir and Mount Prospect Detention




Reservoir would fill only irregularly.  Reference to the DeLeuw, Gather




and Company Report, (Figure XI-3 on Page X-8), indicates that in the 21




years of records studied, the computer simulation study indicated that




the detention basin would detain more than 100 acre-feet only 8 times, and




more than 300 acre-feet four times.  Further, the reservoir remains completely




dry except on 24 occasions in the 21 years of record, or approximately




once a year.  The volume of the detention basin as proposed in the DeLeuw,




Gather and Company Report is 850 acre-feet.  Under the simulated condition,




when the Mount Prospect Basin filled to the greatest extent (810 acre-feet)




during the July, 1957 storm, the basin was empty 19 hours after it began




to be filled.  (This is seen by examination of Table XI-2 on Page XI-5




of the DeLeuw, Gather Report.)
                                4-11

-------
     The Main Reservoir,  on the other hand,  is  a retention basin.   As the

dewatering rate (24 MGD)  is very small relative to the inflow rate during

storms, its size is essentially equal to the volume of runoff in the

combined sewer area.   Therefore the size of  the Main Reservoir is almost

totally independent of the rate of runoff or presence of local retention

basins in the combined sewer area.


     The MSDGC is in the process of entering into an agreement with Mount

Prospect and Arlington Heights for the construction of a 130 acre-feet

storm water retention reservoir on a portion of the site of the proposed

Mount Prospect Reservoir.  This reservoir could be a shallow gravity

type, discharging storm water at a reduced rate to Weller's Creek.  The

construction of this storm water reservoir would be made possible by sewer


separation within the tributary area, to be performed by the Villages of

Mount Prospect and Arlington Heights.

     If the MSDGC proceeds with construction of the Combined Sewer Detention

Reservoir at the Mount Prospect site at a later date, the separate storm

water reservoir could be abandoned and its volume used for the larger

combined wastewater reservoir.  However, based on feasibility studies it

is possible that it may prove feasible to have two reservoirs on the same

site, a storm water reservoir and a combined wastewater detention basin,

thereby not recombining the storm water but continuing to discharge  it  to

Weller's Creek without treatment.

     At the present time the feasible alternate has not been determined

but  this will be established prior to constructing the storm water reservoir.


At this time  the MSDGC does not plan to treat  storm water except where

this is the most economical manner of reducing  combined wastewater-caused


pollution  of waterways.
                                 4-12

-------
     The only sewer tunnel and/or combined waste water reservoir projects




which may be implemented in the next 20 years in the Upper Des Plaines




Service Basin, are the O'Hare (Main) Reservoir, the Mount Prospect Detention




Basin and the Upper Des Plaines Intercepting Sewer 22 (Contract 73-314-2S).




This intercepting sewer will be an earth tunnel which will serve a separate




sanitary sewer service area and will relieve the existing Upper Des Plaines




14A and 14B interceptors in Wolf Road.  The service area, size, location




and other information related to this intercepting sewer are shown on




Figure 4.3.




     No determination of the desirability of constructing the combined




waste water reservoir(s) or additional sewer line has been made in this




EIS.  Possible future connections are reported for the purpose of identifying




some options that are available through implementation of the proposed




tunnel conveyance system.




     The selection of the tunnel conveyance system as the proposed sewer




intercepting system for the O'Hare Service Area does not predetermine




the site of the Water Reclamation Plant.




     The location of the dropshafts, earth and rock tunnels are a function




of the existing sewers  (especially  those serving the combined sewer area),




hydraulic design parameters, and ease of construction and operation and




maintenance.  Nine possible sites are considered in the  siting of the




proposed Water Reclamation Plant (See the Draft EIS on the O'Hare WRP,




Chapter 3).  At each site a 7-foot diameter influent sewer would be needed




to dewater the main 20-foot diameter rock tunnel.  Thus, constructing the




recommended tunnel conveyance system leaves open the site selection process




for the Water Reclamation Plant.





                                 4-13

-------
                         AREA SERVED 15.1 Sq. Miles
                         Design Population 122,616
              ARLINGTON HEIGHTS
UPPER DES PLAINES 22
CONTRACT 73-314-2S
19,000 Ft. of 7'-6" Dia.
$6,750,000.
PROPOSED U.D. 21
TO O'HARE W.R.P.
EXISTING M.S.D.
SEWERS TO
NORTH SIDE W.R.P.
                                        THE METROPOLITAN SANITARY DISTRICT
                                               OF GREATER CHICAGO
                                             ENGINEERING DEPARTMENT
                                    FIGURE 4-3
                                       4-14
                              MAY, 1973

-------
                          CHAPTER  5
                     ENVIRONMENTAL EFFECTS OF THE
                           PROPOSED ACTION
     Four key components have been identified for the proposed action.

They are:

     1)  The tunnels

     2)  Eight drop shafts and one main shaft

     3)  Seventy access manholes

     4)  Nine monitoring wells

     The proposed plan is thus composed of separate component parts, each of

which may produce a given impact or degree of impact depending upon its

location and size.  In addition, the tunnel conveyance system would have

both beneficial and adverse impacts on the area as a whole.  These two levels

of impacts combine to produce the overall impact that would be associated

with the proposed tunnel conveyance system.

     A matrix summary of potential impacts at the end of the chapter indicates

the range and types of impacts involved in the proposed action.

A.  Bedrock Geology

     A large portion of the Rock Tunnel Alternative is located in the bedrock

strata.  The general geologic sequence to be expected along this tunnel

alignment is illustrated in Figures 5-1 and 5-2.  The geology as shown in

these figures is greatly generalized and the location, number, attitude and

condition of faults are totally interpretive and not verified by field

observations.  However, the formations involved with the Rock Tunnel

Alternative are stable and the boring of the tunnel would not cause any
                                5-1

-------
           X '
      LEGEND
           Sr   RACINE
  _U_
   D
           Sjr  ROMEO


           Sm  MARKGRAF
Sk  KANKAKEE


Ob  BRAINARD SHALE





Faults


Formation Contact
NOTE  I.  ELEVATIONS  IN FEET AND
        BASED ON C.C.D (CHICAGO
        CITY  DATUM )

      2  FAULTS REPORTED BY VIBROSEI^
        SURVEY.  HARZA ENGR. CO.
                   GEOLOGY  AT  TUNNEL  ROOF
                                       5-2
                                                                           FIGURE 5-1

-------
NOTE I. ELEVATIONS IN  FEET AND
       BASED ON C.C.D (CHICAGO
       CITY DATUM )
      2 FAULTS REPORTED BY VIBROSEIS
       SURVEY. HARZA  ENGR. CO.
                                                                   FIGURE 5-2
                     GEOLOGY  OF  TUNNEL INVERT
                                         5-3

-------
slipping or instabilities.


     Due to numerous vertical joints and high permeability of formations,


groundwater would seep into the tunnel during construction.   Because the


tunnel would be fully grouted and lined, infiltration would be reduced to a


minimum after construction.


     The linings for all rock tunnels will be 10-inch plain concrete with a


minimum 28 day compressive strength of 4,000 psi.   This concrete is the


MSDGC standard for dense, watertight, durable concrete in contact with sewage.


Linings for earth tunnels will be 12-inch thick concrete identical to that


above, or precast concrete pipe depending on the Contractor's selection of


method of construction.


     In the case of the proposed rock tunnels, the lining serves the principal


function of protecting mudstone partings, present in some of the rock members,


from continuous contact with the flowing sewage.  See Figure 5-3.


     The lining, once in place, serves to further reduce potential infiltration


and exfiltration by providing a continuous, virtually impervious barrier


between the tunnel opening and surrounding rock.  For this reason, it is


believed that infiltration can be reduced below that accomplished with unlined


tunnels.
                         !

     In addition to the concrete lining, the adjacent rock formations will


be grouted where necessary.  This grouting is intended to seal openings in


the rock through which water may migrate either into or out of the tunnel


system.  There is a practical limit with respect to opening size, with which


cement grouting may be effectively employed.  Results of a previous grouting


program of a recently constructed facility indicate that openings with


infiltration rates less than 1/8 gpm are practically ungroutable, using cement
                                5-4

-------
      ROCK    TUNNELS

        Surface
                           EARTH    TUNNELS

                                -Surface
                           +6O
 +52,

5O —
OVERBURDEN:
   ESTIMATED   PREDOMINANTLY
   PIEZOMETRIC
   HEAD UNDER  CLAYS AND SILTS
   MAXIMUM
   SURCHARGED
   CONDITIONS
RANGE OF PREVAILING
GROUND WATER LEVELS
AT TIME OF SUB-SURFACE
INVESTIGATION
                                            CONC. LINING
                                                                        50
                                                 PROPOSED 5
                                                 TUNNELS EARTH
        GENERALIZED  STRATIGRAPHIC  SECTIONS

                             FIGURE 5-3                         5-5
                                                                        75
                                                                        100
                                                                            E-i
                                                                            W
                                                                            w
                                                                        125
                                                                        150
                                                                        175
                                                                        200

-------
grout, with cost effective results.   For this tunnel conveyance system lining




and grouting are intended to augment each other.




     During the construction period, however, such inflow may temporarily




result in a lowered water table in the overlying glacial drift aquifer and




dewatering pumpage may contribute to short-term water quality degradation




(mainly turbidity) in Higgins Creek.




     The proposed system would not be affected by the intensity of future




earthquakes predicted to occur in this area.




     Approximately 350,000 cubic yards of dolomite would be removed during




a 2 to 3 1/2 year construction period estimated for various tunnel segments.




These dolomites and the overlying glacial material represent a natural




resource which should be utilized in a productive manner.




     It is anticipated that the restricted usability of the tunnel spoil




material will reduce its value to an extent where double handling is unwarranted.




Therefore it is not expected that a high percentage of the material will be




stored near the main shaft sites.  However in the event of storage of the




material it can be expected that it will have a lower permeability than the




unpaved ground surface thereby increasing storm runoff.  The minor increase




in runoff and its short term nature minimize the significance of this negative




impact.  The rate of removal w.ill be such that it is not expected to have any




significant environmental or economic impact.




B.  Soils and Surficial Geology




     The proposed project will have no  significant effect on the weathered




surface soils of  the project area, as the construction of the eight drop




shafts and one main shaft represents the largest modification.  There may be




some  soil compaction resulting from the operation of construction equipment
                                5-6

-------
in the vicinity of the drop shafts, manholes, and main shaft.




     The earth tunnel portions of the rock tunnel plan would require removal




of approximately 8,000 cubic  yards of subsoil.  The composition of this




subsoil ranges from clayey silts to silty clays, with occasional sand lenses




and some gravel.




     The 12-inch concrete lining in the earth tunnel portion will protect




the shallow aquifers present throughout these morainal deposits.  Construction




techniques are designed to prevent collapse of the earth tunnel and subsequent




earth settling.  These construction techniques have been utilized in the past




and have proven successful.




C.  Hydrology




1.  Surface Water




     Implemention of the proposed plan would result in the improvement of the




water quality of Weller's Creek and Feehanville Ditch, as combined sewer




overflows to these streams would be reduced.  The 29 area outfalls are




indicated on Figure 5-4.  With the proposed tunnel system in operation,




combined overflows to these streams would be reduced from 80 occurrences per




year to fewer than six.  This would respond to the IEPA Water Pollution




Regulations requiring provision for treatment of all combined sewer overflows




by December 31, 1977.




     A dewatering program will be necessary during the construction of the




rock tunnel, as a flow up to 600 gallons per minute could be produced.  This




water will be discharged into Higgins Creek after the water passes through




a settling basin of sufficient size to permit a one-half hour detention period.




The settling basin will be located near the main shaft.  However, this water




may increase the turbidity of Higgins Creek in the1 short term as the water
                                 5-7

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LEGEND
  A  EXISTING COMBINED SEWER OVERFLOWS

     INUNDATED FLOOD AREAS OF JULY 1957
                               FIGURE 5-4
                   COMBINED SEWER OVERFLOW POINTS
                                                               5-8

-------
will not be retained fpr a sufficient period to eliminate all of the fine




limestone particles.  A discussion of the impacts of the effluent from the




Water Reclamation Plant is discussed in the EIS on the Water Reclamation plant.




2.  Aquifers




     The proposed modifications should have little effect upon the groundwater




of the glacial material and those shallow aquifers in the Silurian dolomites,




as all tunnels will be lined to prevent infiltration and exfiltration.




However, during construction of the rock tunnels, there will be some loss of




water in the Silurian aquifers due to the necessity of dewatering.  There




should be little water loss during the construction of the earth tunnels.




     The MSDGC and its consultants have considered the general subject of




interference with private and municipal wells by construction activities or




by the completed Upper Des Plaines Tunnel Conveyance System.




     The areas of study fall into two general categories — effects during




construction activities and effects after completion of construction.  The




subjects considered relating to construction operations are as follows:




     a.  Clouding or contamination of wells by tunnel .or shaft construction




         operations;




     b.  Lowering of the water table during construction operations;




     c.  Clouding or contamination of wells by grouting operations; and




     d.  Reduction in well yields due to grouting operations.




     The subjects considered relating to post-construction operation of the




completed facility are as follows:




     a.  Protection of the aquifers from contamination by sewage in tunnels;




     b.  Effect of completed facility on water table; and




     c.  Aquifer monitoring well operations, location, and standards.
                                5-9

-------
     Following is a discussion of the potential impacts listed above.




     There are a number of private wells in the vicinity of the 20-foot and




16-foot rock tunnels (Contracts 73-317-2S and 73-320-2S) that may be




influenced by the construction of these tunnels.  The effect on these wells




is anticipated to be limited to some clouding during grouting operations.




These wells are thought to draw most of their water from the soil-rock




contact area.  A monitoring well has already been located in the vicinity




of all known well areas, particularly near areas where complaints of cloudy




water were received during the subsurface exploratory program.  These wells




will receive constant monitoring during construction.  Should clouding




caused by the grouting operations occur, pump-out of the monitoring wells




may be sufficient to prevent the further migration of grout particles.  If




these procedures fail to prevent cloudiness, fresh potable water may be




supplied for the short time required to complete the grouting and for the




water to return to its original state.  Since the grouting is intended to




extend one tunnel diameter beyond the tunnel walls, no long-term effects on




the wells are expected.




     The potential groundwater drawdown within the glacial till-Silurian




aquifer is extremely difficult to predict.  The ability of water to migrate




from the soil-rock into the tunnel±sa function of the number of joints and




bedding planes intersected by the tunneL.  No data is available which will




allow precise arithmethical determination of joints, bedding planes and




opening sizes which may be encountered.  Several factors are known however,




if only in a general way, which enable a review of the  existing soil-rock




conditions and an evaluation of how these conditions may impact groundwater




loss into the proposed conveyance  system.  The known factors are the  results
                                  5-10

-------
of soil and rock boring programs performed for the project,  a review of




conditions that prevailed on a similar project before and after grouting.




     The glacial till throughout the project area is predominantly fine




grained soils with an estimated coefficient of permeability of 10~" to




10   cm/sec.  These soils do not readily release water and consequently will




not cause significant inflows into the tunnel which will be detrimental to




construction or water levels in the soild.  Isolated sand and gravel pockets




exist within the glacial till which are discontinuous and not connected to




the surface.  These pockets will hold limited amounts of water which, if




encountered by construction, will release their contained water.  The quality




of such water appears to be extremely limited and is not known to be used




as a potable water supply.  These wafers will be replaced» in time, after




completion of construction, by natural recharge.




     The Silurian system is described in depth in Volume I,  Bedrock Geologic




investigation of the Geotechnical Report on Upper Des Plaines Tunnel and




Reservoir Plan, Contracts 73-317-2S and 73-320-2S, dated July 1974.  This




report describes the rock systems to be encountered! and postulates the




conditions expected to be encountered during construction.  Since the water




bearing features within the rock consist of openings, primarily in form of




cracks and joints, location of the inflows are easily located after excavation,




particularly within machine bored sections.  It is the intention of the Contract




Specifications that grouting be performed shortly after excavation so that




such inflows will be stopped before the pezometric level can be appreciably




affected over any sizeable areal area.




     Two pump-out tests performed in the course of the subsurface investigations




failed to reflect any affect on observation wells as close as 75 feet away.
                              5-11

-------
This supports the contention of Foundation Sciences, Incorporated, Geologic




Consultant for the project, that intersection of joints will have an




extremely local effect on existing pelzometric levels.




     During construction of a similar project, groundwater actually rose in




nearby observation wells, as a result of seasonal fluctuations.  Also, on




that earlier project, one of the highest inilow areas was adjacent to a




quarry which was open and dry, further indicating the difficulty in predicting




groundwater loss or behavior in the localized area of the proposed tunnels.




     It is anticipated that drawdown of the aquifer during operation of the




facility will be virtually zero.  It is expected that grouting will reduce




groundwater flow into the tunnel to less than 300 gpm over the total length




of tunnels, based on results obtained with previous projects.  The tunnel




lining will further reduce the inflows.  Any openings in the lining which




permit significant groundwater inflows must be repaired.  Any local drawdown




which may occur will be short-term, due to the tunnel tightness, and is




expected to return to the original piezometric level.




     The design storm of July 1957 represents the most severe storm of the




21-year study period having a postulated frequency of occurrence of greater




than once in a 100 years.  During this storm event, the predicted maximum




hydraulic gradient during peak runoff conditions for the ultimate system,




with reservoirs,  will vary between evelation +23 (City of Chicago Datum)  at




the downstream end to elevation +52 at the 16-foot tunnel upstream end.   This




dynamic condition would last for less than one hour.




     Immediately following the storm, the system will fill to static




evelation +52, which represents the maximum design surcharged conditions.




The length of time the water level within the tunnels will be at  elevation
                               5-12

-------
+52 will be approximately 18 hours.  Consequently, there may be a period of

approximately 18 hours that would occur with a return frequency of greater

than once in a 100 years, when the level in the tunnels would be slightly

higher than that of the surrounding groundwater.

     Accurate data is not available on the groundwater levels, or its

seasonal fluctuations.  The groundwater readings taken during the boring

program range too widely to be used with any arithmetical certainty.  Since

the tunnels are being lined due to geological reasons, and since it is

believed that the tunnels can be maintained in a water tight condition,

computations have not been made which would quantify transmissibility

between the tunnel system and the aquifer.

     The following criteria set up by the MSDGC with respect to the aquifer

monitoring wells will apply to the proposed project.

     "To demonstrate that the project is not causing contamination  of
     the groundwater, it will be necessary to set up monitoring programs,
     consisting of sampling wells with instrumentation to provide contin-
     uous recordings of water level and the necessary equipment to extract
     water samples for laboratory analysis.  Instrumentation for recording
     water level within the tunnel will also be required to obtain the
     interrelationship between the groundwater levels and the tunnel
     pressures.

     "Samples will be tested for the following parameters:

     pH              NH -N                 Total Bacteria Plate Count
     BOD             Total Phosphorus      Coliform (M.F.)
     Chlorides       Phenol                Fecal Coliform (M.F.)
     Hardness        COD                   Fecal Strep. (M.F.)
     Alkalinity      Cyanide               Conductivity
                     Mercury               T.S.S.

     Sampling will be performed at each of the wells at two-week intervals

and after each major storm event by the Research and Development Department

of the MSDGC.  Monitoring wells will be installed at approximately one-half

to three-quarter miles along the line of tunnel at a minimum offset distance
                                   5-13

-------
of 30 feet from the edge of the tunnel so as to  be outside the  grouted  area.




Figure 5-5 shows approximate location of monitoring wells considered for




this project.  In order to have continuous information of changes of ground-




water conditions and characteristics due to implementation of this project,




all monitoring wells should be in operation prior to tunnel excavation.




     In response to the concern of certain citizens who experienced well




clouding during the soil and rock exploration program, it is noted that the




nature of the work performed during this program was quite different than




that to be done during construction of the tunnels and shafts.   In the  drilling




of the rock and soil borings, water was used, under pressure, to remove soil




and rock particles.  This water pressure apparently caused a migration  of




soil and rock strata which serves as a water source for private wells.   The




nature of the construction operations will be such that, during excavation




of the tunnels and shafts, no net flow of water  will flow from the construc-




tion areas, but in fact there will be a movement of water, or at least  a




tendency of movement, into the excavation areas, thereby precluding the




possibility of groundwater contamination.




     In areas of the tunnel where infiltration of groundwater into the  rock




tunnels through bedding planes, faults or fractures is encountered, it  will




be necessary to grout at these points.  These openings will be sealed and




groundwater infiltration will be reduced, thereby insuring the maintenance




of the groundwater level above the tunnel and thus eliminating the possibility




of sewage from escaping into the surrounding rock.  The grouting should have




no effect on nearby wells as it is performed with quick setting mixtures




and is thus kept in close proximity of the periphery of the tunnel.




     In the event of any effect on groundwater quality, or potential clouding
                                 5-14

-------

 IIIIIIIIIIIIIIIIIIIIIIIIIIIHllltl
                                               •///, WATER  RECLAMATION
                                               W,.         -IANT
                    MAIN^HAFT
LEGEND

• ••• ROCK TUNNEL
       (APPROXIMATELY 150 FEET BELOW SURFACE)
Illlllllllll EARTH  TUNNEL
       (APPROXIMATELY 60 FEET BELOW SURFACE)
  £  DROP SHAFT

       MONITORING WELL
                                        FIGURE  5-5
                          LOCATION  OF  MONITORING  WELLS
                                                                              5-15

-------
of wells, grouting operations will be stopped until remedial measures have




been taken to insure the necessary protection of the public.




D.  Land




     A map of existing land uses around the conveyance system has been




included in Chapter 2.




     Without the conveyance system, existing conditions of sewer backups




and stream pollution from combined sewer overflows would continue.  The




entire conveyance system is located underground with drop shafts and access




manholes at ground level; tunnelling will require the acquisition of easement




rights.




     Some surface features of the tunnel project will be located in open space




areas.  Further information needs to be acquired regarding disturbances




during and after construction in park and school properties.




     Land use impacts as prepared by MSDGC, are included in Table 5-1.




Existing zoning and land use controls in the service area will impact future




growth.  The anticipated growth of the area has been evaluated by MSDGC




and NIPC staff with varying findings.  The capacity of the conveyance system




to accomodate future proposed growth is sufficient.  Industrial development




has been forecast by MSDGC from 2000 acres in 1970 to 7300 acres in 2000.




At a meeting of the Planning Committee of the Regional Planning Commission




(NIPC), the NIPC staff indicated that industrial growth patterns would be




half of MSDGC's estimates.  However, MSDGC contends that their evaluation of




NIPC documents, rate of  industrial growth and expected growth would support




their  projected industrial acreage figure.




     NIPC planning papers do not include industrial acreage forecasts.




After  a  presentation by  MSDGC to NIPC regarding this issue, the Regional




Planning Commission approved the MSDGC design capacity of the conveyance




                                5-16

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system and WRP.




     Factors in addition to conveyance system capacity will result in




ultimate industrial development of existing vacant acres.




E.  Air Quality




1.  Construction Impacts




     Construction would require the use of large vehicles and trucks,




generally driven with internal combustion engines with the resultant addition




of these air pollutants to the atmosphere.  Under adverse weather conditions,




residents and animal populations in the immediate vicinity of the surface




construction activity could notice an air quality change.  This would be a




temporary condition during construction, lasting no longer than three months




for access manholes, and 32 weeks fo1" the drop shafts.  Total project




construction activity above and below surface and at the main shaft work




area would extend over a 42-month period.  All of these effects, however,




are anticipated to be minor with the continued improvement in vehicle emission




control devices.  Pollutant levels affecting construction workers, especially




those employed in the underground tunneling operations, will be within the




limits of the Federal Occupation Safety and Health Act (OSHA) standards.




     Dust from construction activities at the surface sites could be signifi-




cant without proper controls.  The mechanical ventilation systems used in



underground construction control the quality of exhaust discharged to the




atmosphere.




     Dust raised by truck traffic will be minimized by using hard paved sur-




faces and dust control measures.




     The amount of blasting and thus the volume of particulate matter that




could be emitted from the drop shafts due to blasting will be small and in
                                5-17

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low concentrations.  The rock blasted in the shafts will be wet  by ground-




water.  In addition, it will, by necessity,  need to be matted by rubber




tire or steel mesh mats prior to detonation  of explosives,  to prevent




release of high velocity particles.




2.  Operational Impacts




     Operation of the system will not produce particulate matter.   No




adverse aerosol or water vapor effects are anticipated to be present in the




construction phase of any alternatives.  During operation,  the possibility




of aerosol generation and release from the operation of the drop shafts does




not appear to be a problem.   As presently designed there should  be no net




movement of air out of the drop shafts.  During model studies there were no




observations of aerosolization.  Should it be found that the actual drop




shaft operate differently, the openings to the surface could be easily




sealed without hydraulically affecting the structures.




     A marked improvement in the residual odors reported in the Weller's




Creek area should result from the elimination of the combined wastewater




overflows.  Construction activities should not create odor  problems.  No other




odor problems are anticipated.  The conveyance facilities are designed to




maintain self-cleansing velocities to prevent deposition of solids and




consequent creation of odors so that there would be no detrimental effects




on the population in the vicinity of the drop shafts and manholes.




3.  Mitigating Measures




     Remedial actions to minimize air pollutants would include effective




enforcement of regulations regarding the operation and maintenance of




construction vehicles.  A continued reduction of emissions from these vehicles




would result as provisions of  the Clean Air Act are implemented.
                                5-18

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     The levels of particulate matter resulting from blasting and excavation




could, if necessary, be reduced by scrubbing controlled exhausts of ventilating




systems, effective use of dust control water and chemicals, and cessation




of surface activities during adverse weather conditions.




     Reduction of pollutants resulting form the operation of construction




equipment will require the constant surveillance to assure all operations




are consistent with MSDGC requirements.




F.  Biology




     The natural ecosystems along the tunnel route have already been




extensively altered or eliminated by human activities.   The proposed




project will have short term adverse impact on terrestrial plants and




animals from the construction of dropshafts and manholes.  Vegetation




removed during the project may be replaced to reverse this impact and




restore the habitat for animal life.




     The aquatic ecosystems of Higgins Creek may be adversely affected by




siltation from construction erosion and by fluctuation of water temperatures




produced by the dewatering of tunnels.  Detention ponds should greatly reduce




these problems.  There should be no long term effect on the stream if species




are able to migrate into the affected area from upstream areas.  The long




term effect of the project will benefit water quality and the stream biota




by greatly reducing combined sewer overflows.




G.  Environmentally Sensitive Areas




     Parklands will be affected by the manhole construction of this project.




This has been discussed with other impacts to area land use in Section D.




H.  Aesthetics




     Most of the tunnel construction will occur underground, reducing




its visual impact.  Surface connections at dropshafts and manholes will cause



                                    5-19

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a temporary adverse visual effect,  which will be largely corrected when the




construction site is restored.   Manhole covers,  26 inches in diameter,  will




be visable at the ground surface upon completion of the project and replanting




of the sites.  Dropshafts will  each have two 47  inch outside diameter




manhole frame and cover castings, and one 3 foot 6 inch by 10 foot open




grate visable from the ground surface.




I.  Noise and Vibration




     Noise levels may reach 120 decibels during  construction; however,  most




noise will be intermittent and  generally below 100 decibels.  Noise will be




an adverse, short term impact.   Mitigative measures will be taken to reduce




noise from construction equipment and trucks.




     The operation of exhaust systems during construction might be considered




noisy and objectionable by nearby residents.  Both working shafts are not in




residential areas, but are adjacent to heavily travelled roads such as the




Northwest Tollway and Rand Road; therefore, its  impact should be minimal.




     The tunnel depth should reduce any blasting vibration during shaft and




possible tunnel blasting.  Blasting operations will be planned to maintain




particle velocities at less than one inch per second and vibration potentials




will be within permissible limits depending on the specific sites where




construction operations are planned.  Information programs will prepare the




public for the unavoidable temporary vibrations  and noise.  Construction




schedules would take into account those hours of operation where noise would




cause the least disturbance.  Use of moles will  minimize these problems in




the construction of the tunnels themselves.




J.  No Action Alternative




     A no action decision would result in a continuation of the combined
                                  5-20

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wastewater overflow during peak storms from the 29 outfall points within




Weller's Creek and Feehanville Ditch Drainage Basins.   See Figure 5-4.




This condition, which presently occurs approximately 80 times annually,




would eventually be in violation of IEPA Regulations requiring this waste-




water to be directed to a treatment plant by December 31, 1977.   The




flood hazard would continue to increase.  The sewage generated within basin




would continue to flow to North Side Sewage Treatment Works through over-




loaded interceptors.




K.  Summary




     The proposed projects will result in a significant improvement in




environmental quality, with respect to the water quality of the local streams.




Construction of the projects will, hovever, result in the irretrievable




commitment of certain resources, such as concrete and energy.  Once completed




however, the operational impacts will be practically non-existent.




     The only long-term negative impact resulting from construction will be




the very localized soil compaction in the area of the construction shafts.




This impact cannot be considered significant when viewed in light of the




extensive land development and other construction taking place in the area.




Other negative impacts will be of a short-term nature.  The turbidity of




Higgins Creek will be temporarily and periodically increased due to the




water pumped out of the tunnels during construction.  In order to mitigate




this adverse effect, a detention pond (1/2 hour detention time) will be




provided to allow some settling of the materials.  Construction vehicle




exhaust and dust resulting from vehicle operation will also temporarily




affect localized air quality.  Given the magnitude of other air polluting




sources in the area, the incremental effect of this project will be
                              5-21

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insignificant.  There will be some adverse impacts from the explosives used




in the construction of the tunnels.  The noise vibrations at the surface




will be minimized by careful design and construction controls.




     The most significant impact of the projects will be the improvement




in the water quality of Weller's Creek and Feehanville Ditch, which now




receive tremendous BOD and suspended solids Loadings from the 80 or more




combined sewer overflow events each year.  The proposed projects will reduce




the number of overflows to 6 or less each year.  While this is a significant




reduction, the ultimate objective is to eliminate all combined sewer overflows.




The MSDGC is presently examining various alternatives for dealing with the




remaining overflows.  (See Figure  5-6.)




L.  Findings




     As a result of this EIS, we believe the following actions would serve




to increase the environmental compatibility of the proposed projects:




1.  The Upper Des Plaines - O'Hare tunnel conveyance system can be




    constructed as proposed, provided the necessary environmental




    safeguards discussed in this EIS are implemented.




2.  The MSDGC should take whatever steps are necessary, within their control,




    to insure that the rock extracted during the construction of the conveyance




    system is utilized in the most environmentally compatible manner.




3.  The MSDGC should take additional reasonable measures necessary to




    decrease  the amount of siltation in Higgins Creek due to the water




    pumped from the tunnels during construction.  The possibility of increasing




    detention time  in  the  pond  should be seriously investigated.




4.  Once  the  conveyance system  is  in operation the drop  shaft openings




    to the surface  should  be monitored by  the MSDGC  for  any  significant
                                 5-22

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                               FIGURE  5-6
MATRIX   SUMMARY  OF   IMPACTS
           AREAS IMPACTED                      ALTERNATIVES
                                                              Rock Tunnel
           	              No Action         Alternative
            BEDROCK GEOLOGY                  •                 •


            SOUS AND SURFIC1AL
             GEOLOGY

                 Weathered Soils                  •                 •

                 Soil Compaction                  •                ^K


            HYDROLOGY

                 Surface Water Quality           Q               Q

                 Ground Water Quality            •                 •

                 Ground Water Quantity            •                 •

                 Water Quahty-Higgens C reek      •                I^M


            AIR QUALITY

                 Vehicle Exhaust                  •                |^|

                 Odors                         0               Q

                 Dual                           •                [B

                 Aerosols                        •                 •


            ECOSYSTEMS

                 Wildlife Habitat                 f               Q

             '    Rare and Endangered             •                 •
                   Species

            1OPOGRAPHY                        •                 •


            CLIMATE                            •                 •


            LAND USE

                 Landscaping                     •                I^Pi

                 Traffic  Flow                     •                HH

                 Kethetic Appearance              •                 •
                  (Surface Structures)

                 Permanent Easements            •                 •

                 Combined Overflow Hazard        ^P               f~*\


            NOISE AND VIBRATION

                 Noise                           •                121

                 Vibration                        •                Kl


            KEY:

          B     Negative Impact

          •     No Impact

          f_)     Poaitwe Impact
         I   I    Duration of Impact
                 is Temporary (Construction Period)
                                  5-23

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    odor and/or aerosol releases.   If  these  are  found  to  occur  on a




    regular basis,  consideration should  be given to  the provision of




    covers.




5.   The MSDGC should fully evaluate alternatives to  the combined sewer




    overflow reservoir which may be built on site 2.   The cost-effective




    analysis of alternatives should specifically include  the possible




    interconnection to the main TARP system  presently  proposed.
                                 5-24

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                           CHAPTER 6




                FEDERAL/STATE AGENCY COMMENTS




                   AND PUBLIC PARTICIPATION
(This chapter will be completed after circulation of this




Draft EIS and the public hearing.  It will be included in




the final EIS.)
                              6-1

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                         CHAPTER  7
                        SELECTED REFERENCES
Argonne National Laboratory, Energy and Environmental Systems
     Division.  August 1973.  Airport Vicinity Air Pollution Study.

Brown and Caldwell.  1968.  Design Report, O'Hare Reclamation Plant,
     Metropolitan Sanitary District of Greater Chicago.

DeLeuw, Gather, and Co.  1972.  Preliminary Plans for O'Hare
     Collection Facility.

Flood Control Committee.  August, 1972.  Summary of Technical
     Reports, Development of a Flood and Pollution Control
     Plan for the Chicagoland Area.

Greeley and Hansen.  1962.  Proposed West and Northwest Sewers,
     Metropolitan Sanitary District of Greater Chicago.

Illinois Department of Transportation.  1973.  Summary of Local
     Planning Documents in Illinois.

Illinois Environmental Protection Agency.  March 7, 1972.  Water
     Pollution Regulations of Illinois.

Metropolitan Sanitary District of Greater Chicago.  November, 1973.
     Appendix to the Environmental Assessment, Alternate
     Management Plans for Control of Flood and Pollution Problems
     Due to Combined-Sewer Discharges in the General Services
     Area of the MSDGC.

Metropolitan Sanitary District of Greater Chicago.  November, 1973.
     Draft Environmental  Impact Statement.  A Plan for Control of
     Flood and Pollution  Problems Due to Combined-Sewer Discharges  in
     the General Service  Area of the MSDGC.  (Tunnel and Reservoir
     Plan).

Metropolitan Sanitary District of Greater Chicago.  November, 1974.
     Environmental Assessment Statements for Proposed Projects
     for the Upper Des Plaines Service Basin, O'Hare Tunnel System.

Metropolitan Sanitary District of Greater Chicago.  December, 1974.
     Facilities Planning  Report.  MSDGC Overview Report.
                               7-1

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Northeastern Illinois Planning Commission.  1971.  Regional
     Wastewater Plan.

Northeastern Illinois Planning Commission.  September, 1974.
     Regional Water Supply Report #8.

Walton.  1964.  Future Water Level Declines in Deep Sandstone
     Wells in Chicago Region, Illinois State Water Survey,
     Reprint Series #36.

U.S. Department of Commerce, Bureau of the Census.  1970.
     Census of Population, Numbers of Inhabitants, Illinois.
     PC (DA15-I11-.
                                  7-2

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THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
                         APPENDIX  A

               O'Hare Area Flood Control Activities

                       Design  Criteria
    Wilke-Kirchoff Reservoir,  Project  70-407-2F
    Heritage Park Reservoir, Project 68-815-2F
    .White Pine Ditch Retention Reservoir, Project 72-313-2F
    Buffalo Creek Retention Reservoir, Project 67-803-2F
    WillowHiggins Retention Reservoir, Project 68-836-2F
    Mount Prospect Retention Reservoir, Project 69-308-2F
                             A-l

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   THE  METROPOLITAN  SANITARY   DISTRICT  OF  GREATER  CHICAGO
WILKE-KIRCHOFF RESERVOIR, PROJECT 70-407-2F
     The Wilke-Kirchoff Reservoir is a multi-purpose, excavated flood-
water retarding, pump evacuated reservoir constructed by the Metropoli-
tan Sanitary District of Greater Chicago, in cooperation with the
Village of Arlington Heights, at a cost of $871,000.  The reservoir
occupies a 16 acre site, is 12 feet deep,  ad has a storage capacity of
100 acre-feet.  It serves a 717 acre tributary area and is designed to
accommodate a 100 year storm.

     The Wilke-Kirchoff Reservoir is located south of Kirchoff Road,
and east of Wilke Road in the Village of Arlington Heights.

     The reservoir was designed to serve as a recreational facility, in
addition to its primary function of reducing local flooding.  Possible
winter activities include tobogganing and skiing on a large earth mound
in one corner of the reservoir formed with excavated material.  Summer
activities can include such things as volleyball, basketball, baseball,
soccer, football, and a general play area.  All recreational activities
are supervised by the Arlington Heights Park District.

     The reservoir is excavated in a clay soil.  The side slopes are
7:1, providing easy access to the bottom of the reservoir for recrea-
tional usage.  The bottom and side slopes are sodded to prevent erosion
and to present an esthetically attractive appearance.

     A pumping station, located at the northwest corner of the site con-
tains three variable speed pumps with a capacity of 6.67 cfs to 12 cfs
and two low flow pumps with a capacity of 0.33 cfs.  These pumps can
empty a full reservoir in 6 days.  Most storms, however, will not fill -
the reservoir completely, and the dewatering time will be less than 6
days.  An underdrain system is provided beneath the reservoir floor to
remove the excess ground and storm water and thereby provide maximum
recreational usage of the reservoir bottom.

     Storm sewers draining the tributary area carry the runoff into the
reservoir through two inlet structures.  At low flows, the runoff drops
through a grate in the inlet structures and is conveyed to the pumping
station through the reservoir dewatering system.  The multi-purpose use
of the reservoir is enhanced by use of th.e_low flow bypass system.  The
water from the reservoir is pumped through a 30 inch force main to a
storm sewer that discharges into Weller_Creek, the natural drainage out-
let for the reservoir tributary area.

     Construction of the reservoir began in August 1972, and was com-
pleted in the fall of 1973.  The Metropolitan Sanitary District contri-
buted $736,000 of the construction cost and the Village of Arlington
Heights contributed $135,000.  In addition, 'the Village 'of Arlington
                                  A-2

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
                    i              i
Heights paid $195,000 to acquire the reservoir site and also assumed
the engineering design costs.  The Village will be responsible  for  the
operation and maintenance of  the facilities.
                                  A-3

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          WILKE - KIRCHOFF RETENTION RESERVOIR
           RESERVOIR -  PROJECT NO.  70-407-2F
         OUTFALL SEWER - PROJECT NO. 71-310-2F
SHEET 1 OF 2
              DRAINAGE AREA              717 ACRES
              DESIGN STORM                100 YR.
              PUMPING STA. CAPACITY       36.7 c.f.s.
              CONSTRUCTION COMPLETED
              CONSTRUCTION COSTS         $ 871.000
              LAND AREA                14.6 ACRES
              LAND COST                 $  232,000
DRAINAGE
  AREA   S
      -  i
                                                   EXISTING STQRM
                                                      SEWER
                  VILLAGE OF ARLINGTON HEIGHTS
                      LOCATION MAP
                                      METROPOLITAN SANITARY DISTRICT
                                           OF GREATER CHICAGO
                                         FLOOD CONTROL SECTION
                                                           JAN. 1973
                        A-4

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                  WIIKE - KlRCHOFF RETENTION  RESERVOIR
                    RESERVOIR - PROJECT  NO. 70-407-2F
                  OUTFALL SEWER - PROJECT NO. 71-310-2F
                                                                           SHEET 2 Of 2
         PUMPING STATION
                                                      30' GRAVITY
                                                        OUTFALL
                                RESERVOIR LAYOUT
 •in.
 no

TO

m\

•M

698

•US

NO

 675
Mt

6*C
n.    STORAGE IN BASIN - 100 acre ft.
       TOTAL STORAGE • 100 acre ft.
              RESERVOIR BASIN FIOOR (677 5' I
       SEWER-* «- SEWER-'   21- SEWER-/ 24'
                                          PUMP STATION
                                     PROFJLE
    STORM PUMPS #1. #2 & #3
    VARIABLE -  3.000 to 5.400 gpm
          6.67 to 12.0 cfs • 100 hp
666.9'   SUMP PUMPS  #4 & #5
    CONSTANT - 150 gpm - 0.33 cfs
               7.5 hp
  TOTAL PUMP CAPACITY - 16.500 gpm
                    36.7 cfs
     OVERFLOW @ 689.5' elev.

 PUMP CONTROLS - SPARLING - FLOAT
                                                                              30" R.C.P.
                                                                              GRAVITY SEWER
70S

700

695

890

885

680

675

870

665

660
                                    73 F 539 R2
                                                METROPOLITAN SANITARY DISTRICT
                                                      OF GREATER CHICAGO
                                                    FLOOD CONTROL SECTION
                                                E.E.W.                   JAN. 1973
                                              A-5

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   THE  METROPOLITAN   SANITARY  DISTRICT  OF  GREATER   CHICAGO
HERITAGE PARK RESERVOIR, PROJECT 68-815-2F
     The Heritage Park Reservoir is a multi-purpose flood water reser-
voir constructed at a cost of $270,000 by the Metropolitan Sanitary
District in cooperation with the Village of Wheeling and the Wheeling
Park District.  The reservoir is on a 25 acre site and has an average
depth of 5 feet.  It has a usable storage volume of 112 acre-feet which
serves a tributary area of 447 acres and is designed to accommodate a
100 year storm.

     The reservoir is an excavated storage gravity discharge structure.
The reservoir was designed as a multi-purpose facility for recreation,
in addition to its primary function of reducing local flooding.  A per-
manent lake, about 8 acres in area and 5 feet deep, is provided to en-
hance the recreational features of the reservoir and usage for winter
activities.  Tobogganing and skiing utilize a large earthen hill con-
structed east of the reservoir with material excavated from the reser-
voir.  The adjacent park areas are utilized for all other seasonal
activities.  Recreational activities are supervised by the Wheeling
Park District.

     The reservoir side slopes are 4:1 or less, permitting easy access
to the reservoir bottom except for the permanent lake area.  The reser-
voir area is grassed to prevent erosion and enhance the recreational
use.

     The reservoir is emptied through a 60 inch diameter pipe into the
Wheeling Drainage Ditch.  A flap gate on the 60 inch discharge pipe pre-
vents water from the drainage ditch entering the reservoir during peri-
ods of high water in the Wheeling Drainage Ditch.  The flap gate also
restricts the flow of storm water out of the reservoir until flow capa-
city is available in the Wheeling Drainage Ditch.

     The reservoir construction was completed in 1970.  The Metropolitan
Sanitary District contributed $180,000 of the facility's construction
cost and the Village of Wheeling contributed $90,000 for the construc-
tion and paid the engineering design costs.  The land for the reservoir
was provided by the Wheeling Park District.
                                 A-6

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                 HERITAGE  PARK WEST RETENTION RESERVOIR

                              PROJECT NO. 68-815-2F
                          <
                         DRAINAGE AREA           447 ACRES
                         DESIGN STORM            1QD YEARS
                         PUMPING STA.  CAPACITY        NONE
                         CONSTRUCTION COMPLETED     2-16-70
                         CONSTRUCTION  COSTS       $270,000  TOTAL  (M.S.D. PAID f.
                         LAND AREA                25 ACRES
                         LAND COST (furnished by village)                       M
                                                   RESERVOIR

                                                     RO.
           DRAINAGE AREA
                                                        DISCHARGE
                                                        PIPE
                                 VILLAGE OF WHEELING
                              LOCATION MAP
     i WHEELING RO.

           j| RAILROAD
WHEELING DRAIN. DITCH
WATER EL 638.S WITH
10 YR. RUNOFF •
                    MAX. WATER ELEV. IN
                    RESERVOIR 639.0
   I   > *w—\
30^   \  ^   ,  —

. EL 634.7^      ^-EL 630.
                                 PROFILE
                                                                   METROPOIITAN SAHUMY DISTRICT

                                                                       Of MUTER CHICAGO


                                                                      FLOOD CONTROL SECTION
                                     A-7

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
WHITE PINE DITCH RETENTION RESERVOIR, CONTRACT NO. 72-313-2F
     The White Pine Ditch Retention Reservoir is a project of inter-
agency cooperation that will divert flow from the White Pine Ditch
Watershed to control chronic overbank flooding and sanitary aewer back-
up caused by storm flows entering and overloading the sanitary sewer
system.  The need for additional public services tp assist people in
flooded areas, and the loss of direct access to or around flooded areas
with emergency equipment, is costly to the habitants in both life and
assets.  Diversion of the existing and increased flows from the road im-
provement and urbanization will convey the flows to a reservoir site
with the capacity to store the excess storm runoffs.  Along the water-
course no site could adequately provide the protection from the 100-year
storm event.

     The Dundee Road improvement project, developed and under construc-
tion by the Department of Transportation, State of Illinois, includes
the larger sized storm sewer to divert flows from the White Pine Ditch
to the east.  The discharge of this sewer and the naturally contributing
areas are directed into the retention reservoir of 50 acre-feet storage
capacity.  The reservoir and White Pine both discharge into Buffalo
Creek.

     The Village of Buffalo Grove reported the monetary flood related
losses for the year 1972 to be $50,700.  These losses for the White Pine
Ditch area only involved 119 homes.

     Cost involvement for the reservoir project are as follows:
$120,000 from the Metropolitan Sanitary District, $130,000 from the
Department of Transportation of the State of Illinois, and any addi-
tional cost by the Village of Buffalo Grove.

     In addition to the construction cost for the reservoir, the Sani-
tary District will administer the construction contract and the Village
of Buffalo Grove will secure the land rights upon which the reservoir is
located.

     The Sanitary District has authority to undertake this work and com-
mit funds without a general election.  Plans and specifications were
awarded August 8, 1974.  Work will be completed by May 1, 1975.
                                  A-8

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                         WHITE PINE DITCH  RESERVOIR
ORMMAl WHITE PINE DITCH DRAINAGE
AREA (585 ACRES)

WHITE PINE DITCH DRAINAGE AREA DIVERTED
BY HWHWAV IMPROVEMENT (315 ACRES)
                                             r-J
                                         Up! |   / RESERVOIR BY M.S.D
                                         -H*'! I  /  jSai dstail below)
                                                  STORM SEWER BY STATE HIGHWAY AGENCY
                              LOCATION PLAN
    -> v  )
  I    i  6th grit* by others
  i	•
Ttk to by othtn
                                COtJSTBUCTION PLAN
                                              A-9
                                                              2nd lee
                                                            1st green
             IXHIKIT  3

METROPOLITAN SANITARY DISTRICT
       OF GRtATER CHICAGO

     FLOOD CONTROL SECTION

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
BUFFALO CREEK RETENTION RESERVOIR,  CONTRACT NO. 67-803-2F
     Urbanization of the Buffalo Creek Watershed has,increased storm
runoff and flooding in areas adjacent to Buffalo Creek and the Wheeling
Drainage Ditch in the Village of Buffalo Grove and Wheeling.   To reduce
this flooding, the proposed Buffalo Creek Retention Reservoir will im-
pound approximately 700 acre-feet of storm water.  This valley reservoir
will be an earthfill dam located just west of Arlington Heights Road and
south of Checker Road in Lake County.  A culvert control structure will
pass low flows and limit the maximum discharge from the reservoir to ap-
proximately 250 cfs.  An emergency spillway will be provided to pass
storm flows from storm events that exceed the 100-year storm event stor-
age capacity and to protect the dam structure.

     Additional construction work includes a le'vee or other flood pro-
tection method for the private buildings adjacent to the reservoir site
north of Checker Road.  Checker Road will be raised above the high water
elevation as will the new bridge over Buffalo Creek.  The reservoir site
is approximately 160 acres located west of Arlington Heights Road in
Section 31 of Vernon Township, Lake County.  The site also included some
area in Wheeling Township, Cook County.  Total cost to the District is
estimated at $2,100,000.

     Project implementation will be guided by a Cooperative Agreement
between the Lake County Forest Preserve District, Village of Buffalo
Grove, and the Metropolitan Sanitary District.

     The reservoir site will be a multiple-use facility for open space
recreation uses, in addition to the primary function for flood control.

     The Sanitary District has authority to undertake this work and com-
mit funds without a general election.  Plans and specifications will be
available for bid advertisement in March, 1975.  The construction con-
tract will be let within 90 days after bid advertisement.  Work will be
completed by December,  1975.
                               A-10

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                                            A-ll

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
WILLOW-HIGGINS RETENTION RESERVOIR, PROJECT 68-836-2F


     The project includes the construction of two storm water retention
reservoirs, Willow-Higgins Creek Channel Modifications and Willow Creek
relocation to control the flooding in the Willow-Higgins Creek Watershed
for the 100 year storm event as shown on Exhibit 1.  This provides for
storing flows from the 0'Hare Water Reclamation Plant that exceeds chan-
nel capacity.  The reservoirs will be located in the O'Hare Airport run-
way clear zone areas.  Clear zones are provided at the ends of runways
because of the high noise level in these areas, the need to control ele-
vation of structures in runway approaches and to provide for aircraft
over run conditions and thus are unavailable for individual public use.

     The Ravenswood Reservoir site is located approximately 2750 feet
from the end of the runway 32R-14L and the Lee Street Reservoir site is
located approximately 900 feet from the end of runway 4L-22R.  The
Willow-Higgins Creek Channel Modifications will be a closed concrete
section downstream of the Lee Street Site.  The Willow Creek Relocation
will consist of both grass lined earth channel and closed concrete sec-
tions as physical conditions permit.

     Willow Creek will be relocated generally along the western limits
of O'Hare Airport south of Old Higgins Road, and then northerly to the
Ravenswood Reservoir.

     The project will relieve the flooding problems in the Willow Higgins
Watershed downstream of O'Hare Water Reclamation Plant for storm events
tfp to the 100 year frequency.  Relocation of Willow Creek would facilitate
the future development of O'Hare Airport.  Also, conveying the flow of
Willow Creek drainage area to the Ravenswood Reservoir, will effectively
utilize the greater storage capacity available at the Ravenswood site.

     The flows added by O'Hare Water Reclamation Plant will be stored
at Ravenswood Reservoir when the flow in the downstream channel exceeds
the design capacity.  These added flows will result from the treatment
of flows from an ultimate population equivalent of 439,000 in the service
area and also from the treatment of the storm flows from a combined sewer
area of 8000 acres located in Weller Creek Watershed, part of Upper
Des Plaines Tunnel and Reservoir Plan.
                                        *
     The proposed project would have following long terra effects:

     1.  Eliminate flood damages for storm events up to the  100-year
         frequency and would provide peace of mind to the citizens
         in  flood prone areas.

     2.  Provide storage  for additional flows from the proposed
         O'Hare Water Reclamation Plant.
                                A-12

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THE  METROPOLITAN  SANITARY  DISTRICT  OF GREATER  CHICAGO  -



3.  Facilitate the O'Hare  Airport expansion  program.

4.  Use land located in clear zones for additional  public benefit.

5.  Increase property valuation by control of overbank  flooding
    and thereby increase real estate tax revenues,  even with the
    removal of some private land from the tax rolls for the project.
                                 A-13

-------
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-------
   THE  METROPOLITAN   SANITARY  DISTRICT  OF  GREATER  CHICAGO
MOUNT PROSPECT RETENTION RESERVOIR, PROJECT NO. 69-308-2F
     The reservoir will be an interim facility designed to provide a
certain level of protection to the area until such time as the Tunnel
•nd Reservoir Plan is implemented.  At that time, the reservoir will be
enlarged from 130 acre-feet (interim) to 850 acre-feet (ultimate).  The
basin will function by gravity.  No pumping will be required.

The interim plan involved 130 acre-feet of storage providing relief to
the upstream storm sewer system.  The Village will be responsible for
the measures necessary to convey separate storm flows into the reser-
voir.  Conversion to the ultimate facility will involve enlargement of
the reservoir and conveyance facilities to bring combined overflows
into the reservoir.

     The interim facility will store storm flows only.  The ultimate
facility will include measures to handle combined flows.  The DeLeuw
Gather report, "Preliminary Plans for O'Hare Collection Facility", con-
cerns the O'Hare Tunnel and Reservoir system of which the ultimate fa-
cility will be a part.  The interim facility is not covered in this re-
port.  Detailed design and analysis of the interim proposal will com-
mence subsequent to the completion of negotiations with the Village and
the purchase of the site.

     Drop Shaft No. 1 under the Tunnel and Reservoir Plan for the
 (O'Hare) Upper Des Plaines Basin will be situated at Central Road and
Weller Creek.  The 8,50 acre-foot Mount Prospect combined waste water
detention basin will function  to  limit the flow to Shaft No. 1 to 800
cfs.  Based on a fully developed upstream drainage area, and an unre-
stricted upstream local sewer  system  (exceeding 100-year design storm
 frequency), this flow was exceeded 24 times in the 21 year record period,
 there were 21 times the maximum detention volume did not exceed 100 acre-
 feet.  Twelve times the volume detained did not exceed fifty acre-feet.
The maximum time of detention  in  the  study period was 20 hours.  This
was  for  a recurrence of the July  1957 storm.  In general, the detention
period would be a small fraction  of  the 20 hour maximum even under full
development conditions.
                                 A-15

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ARLINGTON HEIGHTS
                                      Ave.
                                            MT. PROSPECT
                                               VILLAGE BOUNDA2Y
                                     EXISTING M.S.O. SEWER
                                     MT. PROSPECT
  SITE OF  PROPOSED
  MT. PROSPECT
  RETENTION RESERVOIR
  CONTRACT 69-308-2F
                                    THE METROPOLITAN SANITARY DISTRICT
                                          OF GREATER CHICAGO

                                        ENGINEERING DEPARTMENT
                             A-16
                                                        AUG., 1973

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   THE  METROPOLITAN  SANiTARY  DISTRICT  OF  GREATER  CHICAGO
                         APPENDIX  B

                      MSDGC TARP PROGRAM

Combined Sewer Overflow Elimination

     The selected plan for eliminating untreated combined -iewer ove..-
flows or plant bypasses was chosen from various alternatives a~:d was
described in the August 1972 "Summary or Technical Reports,"
by the Flood Control Coordinating Committee.  Since 1972 lo
to sub-systems of the plan have been made as additional s ndies an
sub-surface exploration work have been performed.

     Tills chapter first describes the August 1972 Recommended  Plan
and then describes the five revisions that have been made.   These
revisions do not change the concept of the plan but only present
additional development of the-project to reflect sub~system optimiza-
tion.
August 1972 FCC Recommended Plan

       Description and Maps

       After extensive review of. the alternatives, the Flood Control
Coordinating Committee unanimously agreed that tbe Alternatives "G",
"H", "J" and "S" Mod 3, are less costly and would be more environ-
mentally acceptable to the community than any of the other plans
presented.  Detailed studies and layouts along the lines of these
plans were then continued to develop the recommended plan.

     The system recommended herein, a composite of several  of the above
Alternatives, is outstanding in its relative storage economy and
simplicity.  It will capture the total runoff from all of the record
meteorological sequences of history, if they were to recur on future
ultimate developed drainage basins, except for the peak few hours of
three of the most severe storm events.  The system will convey these
captured combined sewer flows through high velocity, out-of-sight
underflow tunnels below the routes of the existing surface water-
courses to large pit-type storage reservoirs.  Figure M-IX-1 shows
the general location of the conveyance tunnel system and storage
reservoirs.

     The primary storage reservoir is shown located in the area now
occupied by the sludge lagoons of the Metropolitan Sanitary District
in the MeCook-Summit area.  This reservoir will be in the form of a
300 to 330 feet deep rock quarry, with a maximum water depth of
approximately 200 feet, in the heaviest storm ;event,and  water  surface
dimensions averaging about 1,000 feet wide by 2 1/2 miles long.  Total
storage capacity of the reservoir with the water surface as its
maximum level of -100 CCD, will be 57,000 acre-feet.

     Figure M-X-2 shows the general layout of the reservoir, conduits
and pumping facilities.  The lower 100 feet of depth of  the reservoir
                            B-l

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    THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
 will  be divided  into  three  basins  by  transverse  dikes,  providing  two
 small basins,  each with a volume of 5,000  acre-feet  for t.he more
 frequent small runoff periods.  The larger runoff  volumes will  flood
 the remaining  basin and the water  surface  will rise  in  elevation  over
 the entire reservoir.

      The dewatering pumping station shown  on  Figure  M-X-2 will  dis-
 charge from the  storage reservoir  to  the West-Southwest Treatment Plant
 at an average  rate of about 700 cfs.   The  station's  total capacity
 will  be 2400 cfs in order to dewater  the conveyance  tunnels and Stearns
 Quarry into the  reservoir within two  or  three days following a  storm.

      Computer  studies indicate  that the  storage  utilized in Basins 1
 and 2 will exceed  their combined volume  (10,000  acre-feet) at an
 average frequency  of  six or seven  times per year and that: these two
 basins alone will  entrap more than 70% of  the annual combined sewer
 spillage containing over 95% of the annual Suspended Solids.

      The use of  a  deep pit  storage basin of such magnitude and  depth
 requires that  aeration be provided to insure  positive odor control by
 floating equipment.  This is necessary because the range of liquid
 level varies over  200 feet.  It is proposed to use submerged turbine
 aerators provided  xvith a downflow  draft  tube  with  air injection below
 the propeller.

      The submerged turbine  aerators will be provided with a bar screen
 to prevent large ice  chunks from being drawn  into  the draft tube  and
 damaging the blades.   The aerators will be provided  with legs to
 protect the draft  tube and  will need  a minimum of  20 feet of water to
 operate.  When floating at  greater depths, it is considered that
 active aeration  will  be limited to the upper  50  feet of the water in
storage.

      Aerators, in  the heaviest  rainfall  year  will  be in near continuous
 operation in or  above Basins 1  and 2. A lesser  amount  of aeration on
 an intermittent  schedule will be required  in  Basin No.  3.

      An aerated  reservoir of lesser depth  and  a volume of  1,800 acre-
 feet, will be  provided near the proposed O'Hare  Water Reclamation
 Plant, to serve  the combined sewered  area  of  the suburban communities
 to the northwest.

      Another reservoir will utilize  the  existing Stearns rock quarry
 in the vicinity of 28th and Halsted  Streets.  This reservoir will
 provide approximately 4,000 acre-feet of storage space  and will be
 used only during record storm events  to  flatten  out  the peak discharge
 through the conveyance tunnels.
                                 B-2

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
     Conveyance Tunnels

     There are approximately 120 miles of conveyance tunnels inter-
cepting 640 sewer overflow points in the 375 square mile area served
by combined sewers.  Most of the conveyance tunnels will be construclt'il
in the Silurian Dolomite rock formation 150 to 300 feet beiow the
surface of the waterways.  In some areas, the smaller tunnels will be
constructed in the clay overburden.  See Figure M-X-3, 4 for profile---
of the tunnels.

     The tunnels will in general be drilled by mining machine (moles),
except for the largest sizes which will probably be constructed by
the conventional drill and blast method.

     Three main conveyance tunnel systems fork out from the primary
reservoir facility located in the McCook-Cummit area.  See Figure M-X-1.
Figure MX-1.   The Des Plaines Tunnel System extends north alone the
Des Plaines River to the Village of Des Plaines, thence northwest
terminating at the Village of Palatine.  The Mainstream Tunnel System
extends under the Sanitary and Ship Canal, the North and South Branches
of the Chicago River and the North Shore Channel to the Wilmette
controlling works.  The Calumet Tunnel System extends south and south-
easterly along public right-of-way to the Sag Channel, thence eastward
under the Little Calumet, Grand Calumet and Calumet Rivers to near the
State Line.  The storage space in the conveyance tunnel system is
9,100 acre-feet.

     Drop Shafts

     The spillages will be delivered to the tunnels by hundreds of
vertical drop shafts, capturing the present spillage from the existing
riverbank sewer outlets of over five thousand miles of near-surface
sewer systems.  A typical drop shaft is shown in Figure M-X-5.

     The drop shafts will have a split vertical shaft, one side for
water and the other side for air.  The center dividing wall will have
slots to insufflate air in the falling water.  This reduces the impact
when the air-water mixture hits bottom.  An air separation chamber is
provided to reduce the amount of air entering the tunnel.  At the top,
a vent chamber will allow air to escape during filling and to be drawn
in during dewatering.

     Groundwater Protection and Recharge

     The major 'project elements are sited in rock units of the Silurian
System of the geologic strata underlying the Chicagoland area.  These
limestone and dolomite rock units, together with the hydraulically
interconnected overlying glacial drift, comprise the so-called shallow
aquifer of the region which is recharged by local rainfall.
                                  B-3

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   THE  METROPOLITAN   SANITARY  DISTRICT  OF  GREATER  CHICAGO
     Additional data on protection of groundwater  and  limitation of
infiltration into tunnels and storage areas is available  in Technical
Report No. 4, Geology and Water Supply.   This  upper aquifer system is
used as a water supply for individuals and certain municipalities.
However, the water supply for the vast majority of the area is  through
piped systems using Lake Michigan water.

     The preservation of groundwater quality and quantity is achieved
by positioning the project elements in the best available rock  units,
taking advantage of the natural low permeabilities of  the rock  and
augmenting this low permeability by sealing the water  bearing bedding
planes and joints, thus providing for elimination  of the  direct connec-
tions between the aquifer and the project element.

     Additionally, the naturally high piezometric  level within  the
aquifer will provide a positive inward presssure providing additional
assurance against exfiltration of flows.   In those areas  were excessive
groundwater withdrawals occur, adversely lowering the groundwater
table, the added protection could be provided  by artificial recharge
to restore high levels around the project element.  The identification
of this recharge need, however, can only be made after sub-surface
exploration, testing and detailed positioning  of the project elements.

     Benefits

     A brief listing of anticipated benefits to be derived from
completion of the system of flood and pollution control proposed
herein, includes the following:

     1.  Protection of the valuable water resources of Lake Michigan
         from flood release of river water as  now  required through
         the existing Chicago River, the North Shore Channel and
         the Calumet River into Lake Michigan.

     2.  Achieving and maintaining acceptable  water quality (in
         accordance with National Goals and Regulations of the
         Illinois Pollution Control Board and the  Metropolitan
         Sanitary District) in the open waterways  known as the
         Chicago River and its branches, the Sanitary and Ship
         Canal, the North Shore Channel, the Calumet-Sag Channel
         and those portion of the Calumet River, Des Plaines River,
         Salt Creek and other open waterways,  under the jurisdiction
         and control of the Metropolitan Sanitary  District of Greater
         Chicago.

     3.  Reduction of surface and basement flooding by underground
         backwaters or overbank flooding.
                                   B-4

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
     4.  Improvement of recreational values of all surface waterways.

     5.  Increase in property values due to general improvement of
         environment.

Additional Plan Developments

     The plan described in previous sections was produced in 1972.
The intervening two years have provided the opportunity to incorporate
new analysis and information, and improve the Plan accordingly.  These
up-dates can be grouped under five headings, with the revised Recommen-
ded Plan shown on the attached m^p (Figure M-X-6).

     a.  Independent Calumet System:   The most significant revisions are the
separation of the Calumet Area from the Central System and having an
independently operating system with dewatering to the Calumet Plant.
     ,   The decision to separate the Calumet Area was based on detailed
study  ' of operational flexibility and cost.  This study originated
with the recognition that several potential reservoir sites exist in
the Calumet Area, and the cost of the 55,000-foot connection tunnel
($100 million) would be saved by independently operating systems.

         The study considered three alternative concepts,  each with
several variations:

         A.  Maximum Size Intertfe Tunnel Plan;  In this plan, no
storage would be provided in the Calumet area.  All flow would be
directed to the McCook-Sutnmit area terminal reservoir.  Economies
would be realized by concentrating terminal reservoir facilities.
These savings would be compared to the extra costs associated with
conveyance facilities required to concentrate the storage.

     This scheme is similar to the layout shown in Figure  M-X-1 (tS
Recommended Plan from the Summary of Technical Reports) for the
project area remaining after exclusion of the O'Hare sub-project area.
However, these studies included drainage flow from the communities of
Lansing and part of Markham which were not a part of the prior studies
made in support of the Summary of Technical Reports.   This additional
drainage flow is included as well in all other alternatives evaluated
in this study.

             An Intermediate Size Intertie Tunnel Plan.  Storage would
be provided in the Calumet area but it would be an amount  which would
be insufficient to accommodate all of the runoff in the Calumet area
during a large storm.  In these instances, the Calumet area reservoirs
would fill and, subsequently, flow would be diverted through the
intertie tunnel to the McCook-Summit area reservoir.
                                 B-5

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   THE  METROPOLITAN   SANITARY  DISTRICT  OF  GREATER  CHICAGO
             No Intertie Tunnel Plan.  In this scheme,  storage volume
provided in the Calumet area would be sufficient to accept the excess
combined sewer flow in that area.  The Mainstream and Des Plaines Tunnel
Systems would drain to the McCook-Summit area terminal  reservoir.

             Several variations within each of the above  basic concept planr
are possible and were examined in this study so that the  l_east-cost
representation of each of the above concepts could be identified.  This
led to development of twelve separate project layouts for comparative
evaluation, which included different reservoir locations  and tunnel
systems.

Initial Evaluation of Project Layouts;  The evaluation and cost estima-
ting methods employed in the initial phase of this study  are identical
to those used in the studies which are reported in the Summary of
Technical Reports.  The same basic unit costs and cost curves were
used as were the computer programs previously developed.   These were
accepted and used to conduct simulation studies which yielded results
concerning performance of the twelve project layouts.  A  "trial and
error" procedure was employed in the development of these layouts
wherein tunnel diameters and reservoir sizes were first assumed; then,
for selected storm events, the system performance was simulated by
electronic digital computer cooperation; and system performance defi-
ciencies were noted upon completion 'of the computer run.   Adjustments
were then made in tunnel diameters and reservoir dimensions as
indicated by the simulation analysis results.  The procedure was
repeated until all of the twelve project layouts satisfied the perfor-
mance requirements.  These performance requirements were  to limit
the overflow quantities during repeat of the largest storms to prevent
hackflow to the Lake and to treat the captured water at the existing
treatment plants at a rate such that the total flow to the plant
combined with dry weather flow did not exceed 1.5 times average dry-
weather flow.  The estimates of costs of construction of the sanitary
systems were compiled using the cost parameter data developed for the
prior studies.

     The general approach employed in the initital evaluation phase
of this study  is presented here.  The prior studies which are described
in the  Summary of Technical Reports  showed that, of the 21 year
continuous  record of precipitation,  a tunnel-reservoir system which
functioned  adequately in simulation  analysis during the events of
July 12-13, 1957 and October 3-12, 1954 would also  function satis-
factorily  throughout the remainder of the period of record.  Further,
the tunnel  sizes required in any given layout were dictated principally
by conditions which prevailed during the 1957 storm; a storm  which
yielded  the maximum instantaneous peek runoff flow.  Also, the prior
studies  showed  that the  total reservoir storage volumes required
were controlled by  the  conditions which obtained during the 1954  storm.
                                   B-6

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   THE   METROPOLITAN   SANITARY   DISTRICT  OF  GREATER  CHICAGO
Moreover, an approximate correlation existed between the reservoir
requirements established by simulation of the 1957 storm and those
established by simulation of the 1954 storm.

     For these initial evaluation studies, only the July 12-13, 1957
precipitation event was used in simulation analysis step of the work.
This was made necessary because of the large number of computer runs
required and the especially lengthy run-time of the 1954 event simu-
lation.  The July, 1957 analyses yielded the required tunnel diameters
of the several schemes.  The construction costs of these tunnel network-
were computed.  The July, 1957 analyses also indicated reservoir volume
requirements for satisfactory system performance for this event.
These values were extrapolated to approximate total reservoir volume
requirements which would be needed for satisfactory system performance
during the Oc.tober, 1954  storm.  Reservoir construction cost estimates
were then developed.

     Cost comparison of the twelve alternatives was made on the basis
of the sum of the tunnel and reservoir costs.  These were regarded as
the controlling project costs since these two project compontents
comprise approximately ninety percent of the total construction cost.
Additionally, much of the remaining 10 percent of construction costs
consist of modification of surface collection facilities and drop
shafts, both elements being a common and near-constant cost factor for
all proposed systems.

"Least Cost" Alternatives - Detailed Evaluations;  The maximum size
intertie tunnel plan (Scheme 1A), the intermediate size intertie
tunnel plan (Scheme 2E), and the no intertie tunnel plan (Scheme 3A),
having been identified as the most economicaly systems for each of the
three concepts, were examined in greater detail than the remainder of
the alternatives.  Each of these schemes include the use of existing
quarries as reservoirs.  These quarries, already having depths in
excess of 200 feet and large volumes available, had distinct advantages
over other sites with no significant existing storage volume such as
in the sludge lagoon sites.  Preliminary reservoir layouts were made
for these plans and more detailed construction cost estimates were
prepared as shown in Table M-X-1.

     The totals show the cost advantage of 3A, separation.  Addi-
tional advantage is found in the freedom of construction phasing.
                               B-7

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   THE  METROPOLITAN   SANITARY   DISTRICT  OF  GREATER  CHICAGO
TABLE M-X-1  LEAST COST SCHEMES ESTIMATE OF CONSTRUCTION COSTS;  MILLIONS
             OF DOLLARS (Based on a Limitation of Stockpile Height of
             200 Feet in the McCook-Summit Area)   ,

_ Sum of Tunnels and Reservoirs (1972 Costs, Unescalated) _
Item                               Scheme 1A    Scheme 2E  Scheme  3A

                           2
1.  McCook-Summit Reservoir           496         351         286

2.  Thornton Reservoir                 -           56          74

3.  Mainstream On-Line
       Reservoir                       15          15          15

4.  Tunnels1                          691         568         552

5.  Pumping Stations

    a.  McCook-Summit                  71          65-          64
    b.  Stearns Quarry                  8           8
    c.  Thornton-Calumet            _ ^          30          30

TOTAL, without contingencies        1,281       1,093       1,029
^Estimates of tunnel cost require a determination of whether or r>ot
 they are concrete-lined.  The final decision concerning concrete
 lining must be reserved for the design phase of the project and
 completion of subsurface investigations.  This decision cannot alter
 the conclusions of this optimization study because all project:
 layouts will be similarly affected.

^Includes credit for future sale of rock and other future land values.
                                  B-8

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   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
     As a result of these studies, the interconnecting tunnel has been
eliminating and planning and subsurface explorations have been concen-
trated on development of the plan with an independently operating
Calumet System.

     b.  Palatine Tunnel Elimination

         An additional revision is the elimination of a tunnel leg into
the Village of Palatine.  A report titled "Preliminary Engineering
Study of Palatine, Illinois for Intercepting and Holding Combined-
Sewage Overflows" was completed in September, 1973.  Eighteen alternate
solutions were studied.  The lowest cost alternate for a tunnel and
reservoir concept system for Palatine area to connect to the O'Hare
System, as originally proposed was $22,700,000.  Of the alternates
discharging to Salt Creek Water Reclamation Plant, the lowest cost was
$17,300,000; however the recommended tjnnel and reservoir concept
system was estimated at $18,900,000.  It was further established that
construction of a separate new five-year storm sewer system for the
combined-sewer area would cost $11,100,000 and the construction of a
new sanitary sewer system would cost an estimated $12,700,000.  Either
a new storm sewer system or new sanitary sewer system would eliminate
combined-sewer overflows in this drainage basin.

     At the regular Board Meeting of April 22, 1971, the Board of
Trustees of the District approved the U.S. Soil Conservation Service
Upper Salt Creek Watershed Work Plan.  This plan, of which the District
is a local sponsor, is a comprehensive program which will prevent
overflow of Salt Creek in the Palatine area.  The District has already
committed $4,861,000 for seven projects under the Work Plan.  In view
of this program, the flood control benefits of the District's Tunnel
and Reservoir Plan for the Palatine area will not be required.

     The estimated cost of the tunnel and reservoir plan exceeds the
estimated cost of separating sewers within that portion of the Village
of Palatine which has combined-sewers; and therefore, the tunnel and
Reservoir concept is not the cost-effective method for preventing
discharge of combined-sewage to the waterways.

     Therefore, the Palatine tunnel leg in the Northwest Area of the
District has been eliminated and at meetings with the Village of
Palatine the Village Officials have been so informed.

     c.  Mainstream Dual Tunnel System

         A third revision or updating  includes dual tunnels for the
Mainstream System from Summit to Lawrence Avenue.   The August 1972
Plan included a 42-foot diameter or equivalent along this reach.  In
order  to maintain a uniform slope, this tunnel would  have  to  be  constructed
through the Maquoketa shale.  This shale formed from clay sized
                               B-9

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   THE   METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO
particles is a softer rock than the  dolomitic  limestone, and presents
different stability considerations  for  both  long-term use and during
construction.  Thus, the construction in  this  shale will be more costly
than in limestone.

     During 1974, additional rock borings have been made to  further
identify the location of this shale  formation  and additional analysis
have been performed.  As a result,  it has been determined that  the most
cost-effective plan is to construct  a smaller  tunnel first  at the
required slope and at a latter date  construct  a second tunnel which
vould be totally in the limestone formations.   Each of the  dual tunnels
would provide one-half the required  conveyance capacity.
                                      B-10

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TABLE
inc. iw c i nwrwui i MI* oMniiMni uioinii^i
M-X-2 TUNNELS MAINSTREAM SYSTEM (McCook
v/r u r> c. M i c. n v* n e v* M u V 	
I
to Confluence)

SINGLE TUNNEL
LINE
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
49
50
LENGTH
7,095
13,575
8,00
8,600
7,332
8,368
10,992
11,718
8,285
4,095
5,451
4,104
3,823
2,865
24,400
11,300
14,580
DIA.
42
42
42
42
42
42
42
42
42
42
42
42
42
42



SUBTOTAL
TOTAL
Cost
shown exclude shafts
COST
$ x 1000
:? JL/,UUU
15,600
29,800
17,600
18,900
16,100
18,400
24,100
25,700
18,200
10,800
11,900
9,010
8,390
6,290



$247,790
$247,790
, connecting

Dia.
33
33
33
33
33
30
30
30
30
30
30
30
30
30
30





structure
DUAL TUNNELS ;
Stage I Stapp '
COST DIA. CO,
ft x 1000 $ x
10,820 35 7,810 \
20,700 35 14,930
12,200 35 8,800
13,120 35 9,460
9,750
11,130
14,620
15,590
11,020
6,520
7,250
3,650
3,400
2,550 35 3,150
35 26,840
35 12,430
35 16,038
$152,890 $110,958
$263,848
and contingences
B-ll

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   THE   METROPOLITAN   SANITARY   DISTRICT  OF  GREATER  CHICAGO
     The Table M-X-2 compares the construction costs of the single tunnel
with the costs of the dual tunnel system.  As can be seen the cost
difference  is $16 million or 6 per cent of the total.  This difference
is  insignificant when considering the total costs of the program.  There-
fore, also  considering the uncertainties of grant funding, the dual
tunnel system is chosen because the first tunnel can be constructed at
a lower initial cost and provide for the capture of in excess of 80 per
cent of the pollutants now discharged to the waterways, and thus obtain
an  early return on the invested funds.  The dual tunnel system also
offers time to further optimize the size needed for the second tunnel
to  meet project objectives.

     d.  Mainstream On-Line Reservoir

         Another revision has been elimination of Stearns Quarry as the
location of the Mainstream On-Line Detention Reservoir.  This reservoir
has been included in the Plan in order to reduce the size and cost of
the Mainstream Tunnel System.  Without such a reservoir, the lengthy
Mainstream  Tunnel would have to increase in size from a 42-foot diameter
equivalent  tunnel to a 55-foot diameter equivalent tunnel'^',

         The Stearns site is now being filled in and will eventually
be  used as  a park.  The previous studies had considered this site only
in  relation to evaluating different alternatives of solving the combined-
sewer overflow problem, and not in terms of the specific details of the
site.  It has now been determined that the best and highest use of the
site is as  a park.

         In its place, a Mainstream On-line Reservoir at an unidentified
site is included.  The location of this reservoir can be anywhere along
the tunnel  between the Stearns site and Wilmette Harbor.  Since this
reservoir will be used only during the large storms of record to reduce
the peak flow rates to the tunnels, it will be one of the last facilities
to  be constructed.  If a suitable site is not found for the reservoir,
the alternative does exist to increase the size of the second tunnel of
the Mainstream Dual Tunnel System.

     e.  Des Plaines Watershed

         A  fifth revision provides for the total capture of  the combined-
 sewer overflows in the Des Plaines River Watershed.  The August 1972 Plan
 included the equivalent of a Mod 3 level of capture for the  sizing of  the
Des Plaines River Tunnel and the O'Hare Northwest System.  However, as
was stated  in the report, total captvire would be needed in order  to meet
 the higher  water quality standards of the General Use and the Public and
Food Processing Water Supply Designated waterways. (See Figure M-X-7.)
This was the case in the Little Calumet River and the North Branch of
 the Chicago River Upstream with its junction with the North  Shore Channel.
Tunnel  sizing is provided so as not to spill into these waterways.
                                    B-12

-------
   THE  METROPOLITAN  SANITARY  DISTRICT  OF  GREATER  CHICAGO  —
     The higher water quality standards for the above waterways includes,
among others, the requirement that the dissolved oxygen level shall not
fall below five milligrams per liter at any time.  The computer simu-
lation of the overflows into the Chicago and Calumet River Systems
(designated as secondary contact waters) demonstrates that depression of
the oxygen levels below five milligrams per liter will occur.  Since ther^
latter waterways have a lower water quality designation and instream
aeration is to be provided the Mod 3 level of protection is judged to be
adequate.   However, it is not judged to be adequate in the Des Plaines
River Watershed.  A computer model of the Des Plaines River has not been
developed as for the above waterways.  However, the same level of contami-
nants would be discharged during overflow and the results can be expected
to be the same.

     Therefore, the plan now includes reservoir capacity in the O'Hare
Area to provide for total capture and increased sizing in the Des Plaines
River tunnels to transport a higher rate of flow to the Mainstream-
Summit Reservoir.

     In the O'Hare Area, the August 1972 Report provides for an 1800
acre-foot reservoir including capacity for Palatine.  Subsequent
Analysis &' demonstrates that 1280 acre-feet is required for the
equivalent of Mod 3 level storage for the O'Hare sewered area and 2700
acre-feet for total capture.  Provision for the latter quantity of storage
is being included in the Plan.  The sizing of the tunnels is not changed
because of the decision to include total capCure.  The tunnel size has
been chosen to transport dry-weather flows to the O'Hare Plant, and on
the basis of transporting peak storm flows wi.lh an On-line reservoir
providing for the detention of peak flow rates so as to control the tunnel
surcharge.  The cost of both the 2700 acre-foot O'Hare terminal storage
reservoir and the On-Line reservoir is included in the Plan.

     The Des Plaines River Tunnel has been increased in size to provide
for total capture.  This size increase is shown on Table M-X-3.  The
original size was picked such that spillage to the waterways occurred
during a repeat of the July 1957 storm, (the storm of record for rate of
flow) at  approximately the same ratio to total flow as in the Chicago
and Calumet River Systems:  During the 1954 storm (the storm of record
for total volume), there was no spillage to the Des Plaines River and the
total flow was transported to the reservoir.  Thus, no additional storage
volume is needed to provide for total capture and only increased tunnel
sizing is required.
                                 B-13

-------
	 	 — inc. w c. i nwr uui i MII oMitiiMni uioimui ur ontMltn uniUAUU 	 •
TABLE M-X-3 TUNNELS- DES PLAINES RIVER SYSTEM

LINE LENGTH TOTAL CAPTURE
(ft.) DIA. (FT.) COST
($ x 1000)
18 8800 36 15,224
19 5040 15 2,974
20 11,280 10 3,948
21 9460 36 16,366
22 12,200 32 17,690
23 11.200 15 6,608
24 8160 32 11,832
25 14,390 32 20,866
26 5100 32 7,395
27 8600 24 8,600
28 7050 24 7,050
29 10,380 24 10,380
30 6470 24 6,470
TOTAL 11 ft, 130 135,403
Cost shown exclude shafts, connecting
MoD 3 LEVEL PROTECTION
DIA. (FT.) COST
($ x 1000)
30 11,704 ,
15 2,974
15 6,655
30 12,582
25 12,810
15 6,608
25 8,568
25 15,110
25 5,355
25 9,030
25 7,403
20 8,304
20 5,176
112,279
structures and contingencies
B-14

-------
                     THE RECOMMENDED PLAN
                           AUGUST 1972     V
• STORAGE
  RESERVOIRS
O TREATMENT
  WORKS
                       FIGURE  M-X-1
                     B-15

-------
                                        ><
                                        oe
                                        =3
                                        O
      DEVELOPMENT  OF  A  FLOOD AND POLLUTION
     CONTROL  PLAN FOR THE CHICAGOLANO AREA
         PART 5 - ALTERNATIVE SYSTEMS

PRELIMINARY  LAYOUT  OF STICKNEY  RESERVOI

 B-16           DECEMBER. 1972

-------
I»CUS«NOS Of Fill— 0    10    20    30    40    50    tO    10
    STORAGE       SANITARY AND SHIP CANAL         SOUTH
                                            ao    90   too    no
                                            NORTH CHICAGO RIVER
                                                              NORTH SHGRf  -,','il
    RESERVOIR
                                 CHICAGO RIVER
                        MAINSTREAM SYSTEM
* 1 e |5
I h j a1
»J?i 1UM8IH-* ) 7 33 36 37
! ! 1 i
i 1 ' ;
*1GO *
• 1 1
I I i
39 *0 '
! I
1 1
i
iils

|
l
i
5" M J
45 4G 4E
t

! ' ,__^._*-r""
 -400
 THOU5ANOS 0' HC— 0     W    20
    STORAGE _       	
    RESERVOIR
                          40    50    60    10
                         OES PLAINES RIVER
                                                                MBq^kc a i-ui-
                              100   110    120   130   UO
                              O'HARE AREA      PALATINE BRANCH
                     DES PLAINES RIVER SYSTEM
P
h
        	-J- 	"
                    .   Si  i II  ia
                    II  I!  J I!  II
                                 -100

                                 -200
0    10    •'O    30    40
    NORTH BRANCH CHICAGO RIVER
05   05
CHGO    SOUTH
RIVER    FORK
   MAINSTREAM BRANCHES
i \ ill ill
I * S £ 1 1 .
3 34 35 37 38 0
1


LV fttf

— ^

.
I
•2GO
•100
0
-too
-203
-300
                                                   10    20
                                                SALT CREEK BRANCH    AOOISON
                                                              CREEK
                                                                       FEEHANVIUE
                                                                         DITCH
                                           DES PLAINES RIVER BRANCHES
                        TUNNEL  PROFILES
                B-17          FIGURE   M-X-3

-------
NODE NUMBER—   12
• 100
p
o
o -100
Z
o

< -200

UJ
   300



  -400
                                  Silunan Dolomite -
                                        iure •

                                        ytt''"tod s" '	-\  !!"""   !["~^"oi.7i"
                               30' Dio IT i •
                                                                                         /CO
THOUSANDS OF FEET— 0
     STORAGE   HARBOR BELT
                              30     40
                               HARLEM AVE.
                                          50
     RESERVOIR '    R.B.
                     4-
60     70     80

 CAL. SAG CHANNEL
                                                                   so
                                                                         100
LIHLE CALUMET
                                                                               no
                               CAL.
                                                                                      - ---320
                                                                                     120
                                                                                     GRAND
                                                                                        -400
                                                                               RIVER CALUMET
                                  CALUMET SYSTEM
X gj
» s ;
I i •

£ =i
1 _i g
' . m B 5 S
I 1 II a 1 • 1 I ?
£*• CO ?-. no S- too
NODE NUMW1— 27 20 21 22 23 24 25 24 31 3

O
o
X
o
< -200 .
LLJ

THOUSANDS OF BET—







-—-1 	 1_ _ 	 _, 	 pl__l


1
75' Olo. 2
_„, 	 •'-•
— 	 »»— «-^




1 10
Siliiddi Dolomite

0- Dla. I/' Dia. 1S' Pl°'- —
1
1
L




	 ,


20 30 40
LITTLE CALUMET RIVER







V .
1


- 	 -..__!_
i^
IS' Dlo. 1



1 10




YTERCONNECTIDN
                                CALUMET BRANCHES
                               TUNNEL   PROFILES
                                     FIGURE   M-X-4
                                           B-18

-------
                                         VENT CHAMBER
               ENTRANCE
                 CHAMBER
CONNECTING PIPE
             WATER SIDE
                                              TOP OF ROCK
                                            AIR SEPARATION CHAMBER
                                                ROCK TUNNEL
              TYPICAL  DROP  SHAFT  STRUCTURE
                          FIGURE  M-X-5
                               B-19

-------
          TUNNEL AND RESERVOSR PLAN
     I    eo<
     *
        -1*
 A ON-LINE RESERVOIR
—ROCK TUNNEL

 0 STORAGE
  RESERVOIRS
 a TREATMENT
  WORKS
                                                       ,.!/ COUf
                             B-20
                                                          NOV. 1974

-------
•!•" B	„	Ufl
                                                                  THE METROPOUTAN
                                                                  SANITARY DISTRJCT
                                                                 OF GREATER  CHICAGO
                            r"-,..;.
            GEN. USE AND WATER SUPPLY  ^
            GEN. USE ONLY
 !           SECONDARY CONTACT

            TREATMENT PLANT
        v  ^
         r •«««•_«!
                                                             METROPOLrrAN  CHiCAGO

                                               FIGURE   M-X-7
                                       B-21

-------
                       APPENDIX  C
 THE METROPOLITAN SANITARY DISTRICT OF Grt£ATER CHICAGO

            POSITION PAPER ON SELECTION OF
          UPPER DESPLAINES SERVICE BASIN PLAN
            OVER OTHER SUGGESTED ALTERNATES

     The O'Hare Facility Area  (Upper DesPlaines Service Basin)
is a 58 square mile area in 'the northwest region of the
Metropolitan Sanitary District. At present, all sanitary sewacie
and the combined sewage finding its way into District inter-
ceptors through regulated control structures, is diverted
through existing interceptors to the District's Northside
Sewage Treatment Works for treatment. Initially, following
annexation into the District of most of the area in 1956,
it was planned to transmit sewage flows for the District's
northwest area to the West-Southwest Sewage Treatment Plant
in Stickney for treatment. However, further study indicated
the cost-effectiveness and desirability of dividing the north-
west area into four  (4) service areas. This Paper gives, in
detail, the planning history and rationale of dividing the
northwest area of which the O'Hare Facility Area is a part,
into four  (4) facility  (service) areas.

     Collection and treatment of sewage generated in this
basin has been the subject of many studies and reports. In
1961, the Sewer Design Section of the Metropolitan Sanitary
District recommended that the Northwest Intercepting System
be constructed to relieve existing sewers in the northwest
portion of the District to provide service for the ultimate
development of that area  (Ref.1). The northwest area comprises
the O'Hare, Salt Creek, Hanover Park and Poplar Creek  (Elgin)
Facility Areas as shown in Figure 1. The consulting firm of
Greeley and Hansen was-retained to investigate this proposal.
Based on their report, submitted in 1962, a tentative decision
was made to convey all sewage from the area to the West-Southwest
Treatment Plant  (Ref.2). Further investigation of this proposal
indicated that the cost and magnitude of the project would
require such time and resources as to necessitate construction
of temporary plants  in the northwest area  (Refs.1,2). Additional
studies and investigations carried out primarily due to the
trend toward higher  standards for disposal of treated effluent,
indicated the advisability of collecting and treating the
sewage from each facility area  in the northwest area separately,
since construction of temporary tertiary treatment plants, of
the magnitude indicated, would  not be cost-effective  (Ref.3).
Furthermore, the District considered that diversion of substantial
quantities of water  from the northwest area would not be conducive
to water reuse. The  utilization of tertiary quality effluents for
stream augmentation, within the area, was considered to have

                          c-i

-------
C-2

-------
environmental and recreational benefits. The Northwest Inter-
cepting Sewer proposal would have diverted all sewage flows
from the area for treatment at West-Southwest Treatment Plant
and treated effluent would be discharged into the Sanitary
and Ship Canal at Stickney.

     As a consequence, the Northwest Area was divided into
Facility Areas corresponding to existing drainage basins:
Upper DesPlaines Service Basin, O'Hare Facility Area; Upper
Salt Creek Service Basin, Salt Creek Facility Area; Upper
DuPage Service Basin, Hanover Park Facility Area; and Poplar
Creek Service Basin, Poplar Creek  (Elgin) Facility Area.

     A preliminary design concept for the O'Hare Water Reclama-
tion Plant and intercepting sewers was prepared in report form
by Brown and Caldwell, consulting engineers, in 1968  (Ref.4),
The contract plans for O'Hare Water Reclamation Plant have been
prepared by Consoer, Townsend and Associates, consulting engineers,
and are presently under review by the District. Preliminary  plans
for two  (2) collection facilities systems were prepared in a
report by DeLeuw, Gather & Company, consulting engineers  (Ref.5).
One system would divert total sanitary sewage flow only within
the basin to the O'Hare Water Reclamation Plant; the second
system would convey all sanitary sewage to the plant but would,
in addition, eliminate combined sewer overflows by collecting
and storing for treatment, all combined sewer overflows presently
discharging to waterways within the drainage area. They are
presently developing contract plans for the O'Hare Tunnel System
as part of the second system.

     In 1973, The Corps of Engineers published the Chicago-South
End of Lake Michigan Study  (Ref.6). The investigation included
the O'Hare Facility Area and the O'Hare Water Reclamation Plant
was defined in three of the five alternates presented in the
Report.

     Northeastern Illinois Planning Commission  (NIPC) included
the District's plan for the O'Hare Facility Area  in  its  "Regional
Wastewater Plan" in 1971  (Ref.7).  This  plan has been revised a
number of times since  (Refs.8,9,10,11,12) but revisions have not
affected the O'Hare Facility Area  except to include  the District's
Tunnel and Reservoir Plan as a  regional solution  to  the combined
sewer overflow problem. The first  three NIPC  Plan  revisions  have
been certified by the State of  Illinois and the Federal Government
in accordance with 40 CFR 35.565  (Refs.8,9,10).

     The review of the planning history indicates  that the
division of the District's Northwest area into four  facility
areas is cost-effective and environmentally sound  and has been
                            c-3

-------
recognized by NIPG,  the State of Illinois and the Federal Government.
The District's comprehensive plan calls for collection and treatment
of sewage within each facility area separately.   For the O'Hare Facility
Area, the District has planned a collection system designated as O'Hare
Tunnel System and a treatment facility, O'Hare Water Reclamation Plant.

     It is, therefore, clear that the selection of the Upper Des Plaines
Service Basin Plan over other alternates suggested was a sound judgment,
based on a number of detailed engineering studies concurred in by a multitude
of governmental agencies.  Based on the results of the studies and
concurrence of the applicable regulatory and planning agencies, as well
as the majority of the affected communities, decisions have been, made ami
actions taken over a number of years which weigh even more heavily in
favor of continuing the proposed course of action as- expeditiously as
possible.  The initiation of new studies and reconsideration of numerous
alternates suggested by individuals untrained in the relevant fields of
endeavor and uninformed in the history of past decisions and the multitude
of facts and data drawn upon in making these decisions is unwarranted.
                                C-4

-------
REFERENCES:

    1.    MSDGC,  "Recommendation for Site Acquisition
          for Additional Sewage Treatment Plants for
          Northwest Section.of Cook County, Salt Creek
          and DesPlaines River Areas," June 25, 1964

    2.    Greeley and Hansen,"Proposed West and Northwest
          Sewers," MSDGC, 1962

    3.    Greeley and Hansen,  "Report for Northwest Area",
          MSDGC, 1968

    4.    Brown and Caldwell,  "Design Report, O'Hare Re-
          clamation Plant", MSDGC, 1963

    5.    DeLeuw, Gather &  Company,  "Preliminary Plans for
          O'Hare Collection Facility", MSDGC, 1972

    6.    Corps of Engineers,  "Chicago South End of Lake
          Michigan Study",  Chicago District, 1974

    7.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", March, 1971

    8.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", Revised September, 1971

    9.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", Revised October, 1971

   10.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", Revised January, 1972

   11.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", Revised July, 1972

   12.    Northeastern  Illinois Planning Commission,
          "Regional Wastewater Plan", Revised October, 1972
                          C-5

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                      APPENDIX  D








BEDROCK GEOLOGY





        This  description of the general bedrock geologic conditions





in the  study area is complemented by the analysis of field borings





as reported in The Geotechnical Report on the Upper Des Plaines





Tunnel and Reservoir Plan,  Volume 1,  Bedrock Geologic Invest i -





gation, 1974, De Leuw,  Gather & Company.




       The limestone and dolomite rock units, together with the





hydraulically interconnected overlying glacial drift, function as





an aquifer.




        Rocks in the project area date back to the  Upper Ordovician





Period.  They consist of mudstones,  argillaceous dolomite, pure





dolomite and unconsolidated or semi-consolidated glacial deposits.





Stratigraphic hiatuses (disconformities) occur between Middle Silurian





and Pleistocene, and between  the Lower Silurian and Upper Ordovician





age rocks.   Local lensing may totally remove some rock units




(Waukesha Formation).   See Exhibit II-1.




       The lowering of sea level which produced the disconformity




at the end of  the Ordovician period resulted in local valleys cut as




much as 150  feet deep in the underlying mudstones.  With the re-





advance of the sea, these valleys were subsequently filled with




the shaley dolomite of the Edgewood Formation, which was  not






                           D-l

-------
System
QUATERNARY
SILURIAN
ORDOVICIAN
Series
( 1
/ Pleistocene S
(
Niogaron
\
Alexandrian
Cincmnatian \
Formation/Member

WADS WORTH
MEMBER
WEDRON
FORMATION
h-^ " *,.«—-*>. ,.r— • ,-r— * -— *-—


RACINE
(0 -300')


(WAUKESHA)
(0-20')
JOLIET
(4O-7O'J
Romeo
Markgraf
Brandon
Bridge
KANKAKEE
(20-50')
(EDGE
(0-
^-*-*^~^~—^-
|
£ BRA
o SH
1 (0-
1
t>
0
'WOOD)
100')
MFDA
(0-15')
INARD
ALE
100')
Base
Column
%
/
y4
/
"/"i.
/
/
I
?:<
tri
/
^
/'
^
/
/,
f:
/
:•:-)/
/
/
i^.
/
/
1
1
1
/
1
/
\




•^

/
h


rJ
I] \
1
I
L


1

/

j



1s


y


\

/
/
/ /
/
\ /
/X /


/

^
__

^
'not desert
~!
Description

Till and outwash deposits. Clayey silt with
sand lenses. (Gravel lenses possible but not
probable - described in soils report. )
Bouldery till, clayey silt with sand lenses,
gravel, boulders common near base and at
unconformity. (Described in soils report. )
Gray- brown, argillaceous, fine groined,
thin bedded dolomite containing reefs
of pure, gray, massive, vuggy, dolomite.
Gray, fine grained, silly dolomite.
(Generally absent m northern area )
Light gray, pure, porous dolomite.
Light gray, si I ty, very fine groined dolomite
Red or greenish gray dolomite and
mterbedded shale.
Light brown, fine groined dolomite with
prominent wavy clay partings.
Brown to gray sha/ey dohmite.
(Cherty near top. Not recognized in
project area J
"^^^"/•Z^-jT^ ^""^^^T ~i^7~^77C~* J""~~< g~^^~" ^~"~ ' — ' —
Oolite and red shale. (Generally absent)
	 Green to brown fossiliferous mudstone
tied
STRATIGRAPHIC SEQUENCE
              D-2

-------
recognized in any of the rock cores recovered during the explorations




reported herein, but which may exist in local areas of the project.




       The stratigraphic sequence used in this report has  been




developed from rock cores taken along the project alignment.




No surface rock exposures are available for study.  The rock units




used follow as closely as possible formational units as described in




the literature (Willman,  1971  and 1973), but vary somewhat in the




designation of formational member units as the contacts between




member units are gradational and thus subject to  personal judgment.




 Bedrock Surface





       The bedrock surface is covered by glacial till throughout




the project area; the bedrock  contours shown in Exhibit II-2 are based




totally on interpretation of boring data and are generalized.  The
                             D-3

-------
                                                               :*W»:
                                                                   •H*"*:*!:!
EXHIBIT 11-2
NOTE  I. ELEVATIONS IN FEET AND
       BASED ON  C.C.D (CHICAGO
       CITY DATUM )

      2 FAULTS REPORTED BY VIBROSEIS
       SURVEY  HARZA ENGR. CO.
                      CONTOURS  ON  TOP  OF  ROCK
                          AND  BEDROCK GEOLOGY
                                                                             D-4

-------
bedrock relief in the project area is over 60 feet.





       The rock units at the till,/rock contact are the Niaguran





age dolomites of the Racine and Joliet Formations.  The top of





rock surface is  usually broken and open for five to ten feet and





occasionally carries significant quantities of water.





Stratigraphy





       A detailed discussion of the stratigraphy of the study





area can be found in the Foundation Science Report,  A Geotechnical





Report on the Upper Des Plaines  Tunnel and Reservoir Plan, pre-





pared for De Leuw, Gather & Company.





Structure





       The geologic structure described in this report is based





solely on interpretation of boring data.  No exposures of bedrock





are available for study in the project area.  Therefore, the





situation presented in maps and sections must be used in  its





broad diagrammatic sense only.





       Faults.  A  number of faults of ten to 30 feet vertical offset




are postulated.   The faults are interpretive and have not been





physically observed,  but they do further explain stratigraphic





facts developed  by the boring  program.  None of the borings





actually intersected a  major fault zone.  In many cases, strati-
                            D-5

-------
graphic offsets of a single fault are probable — the result of more





than one fault of smaller proportion stair-stepped to produce the





total offset.





       With borings spacer! a I  1,000-foot centers, as m (his





program, il is also possible for fault blocks of greater  or  lesser





proportion than those shown  !o exist between borings and not be





represented on geologic maps and sections.  The general structural





trend for faults is expected to be NE-SW and NNW-SSE.  The actual





fault trends indicated on the  accompanying map are interpreted from





apparent bedrock drainage displacements and may or may  not in





fact represent actual conditions.





       Three angle borings were drilled to try to sample a fault





zone.  No significant amounts of faulted or gouged rock could be





identified in any of these holes although a few core Loss zones





occurred which may represent small shear zones.  However, the





rock on either side of the core loss zones  does not appear  bisected





as might be expected if a major fault zone were nearby.





       The Des Plaines Disturbance.   The project is immediately





west of a geologic anomaly known.as the Des Plaines Disturbance.





This disturbance is a five- and one-half-mile-diameter area having





a very complex system of high-angle faults.  Fault displacements
                          D-6

-------
along the edges of the disturbance range from ^0 to 300 feet,  and





in the interior reach 900 feet.  Thus,  faulting may he aptly described





as severe,  and the fault system may be expected to extend some




considerable distance away from the boundary of the disturbance.





Shear zones associated with the fault system would cause support





problems and would yield high  volumes of water.  Because of the





anticipated  areal faulting, water infiltration problems would prob-





ably be severe.   Also, because of the offsets across individual





faults, it would be difficult to avoid the contacts betwe.-n rock





meiiV rrs,  again adding to water inflow and support p ro!>] ruus.





        Jointintj.  Joints,  although not numerous in the  rock,  have





a significant influence on its permeability and local tunnel stability.





The open joints act as a  conduit to carry groundwater from the





overlying glacial till to the bedding  planes in the upper rock units





(Racine and Joliet Formations).  The  numbers of the open joints





are relative indicators of the amount  of groundwater to be





expected in a given rock.  Those data  clearly demons! rau- Hie





more open  and permeable natures of the Racmc and Upper .loliel





(Romeo) Formations.
                             D-7

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        Earthquakes.  In the past,  damage from earthquakes has





not been extensive or severe in Northern Illinois.  Past disturbances





have ranged in intensity up to VII on the  Mercalli scale, but a VII





intensity was  recorded only once in history.  Presently, the study





area is in Seismic Risk Zone 1,  an area  predicted to experience





only minor  damage from earthquakes that have the epicenters





outside the  state.   Intensities of the disturbances are predicted





to range from V to VI on the  Mercalli scale.   A V intensity distur-





bance; is felt by nearly everyone and breaks glassware and windows.





A VI intensity disturbance is felt by everyone; objects are upset;




and chimney and  plaster damage occurs.






SOILS AND SURFICIAL GEOLOGY




        The basic drainage patterns,  landforms and soil parent





materials are related to the  Wisconsin glaciation.  Glacial deposits





may approach depths of 60 feet in this area.   The texlural composi-





tion of these morainal till deposits range from clay to  clayey silt,





with varying amounts of sand, gravel and boulders.  At the  earth





tunnel  depth,  the soils range from clayey silts to silty clays, with





occasional sand  and gravel.  In this area, the Tinley Moraine





directly overlies the Valparaiso Moraine.  The  Tiriley Moraine,





predominately .1 silty clay,  m
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                                                 APPENDIX   E
REGIONAL WATER RESOURCES AND  NEEDS

SECTION A

Sources of Water Supply

2.01 GENERAL  At  the   present  time,  Lake  Michigan  and
groundwater are the  sources for public  water supply in north-
eastern Illinois. Groundwater is developed from four aquifer sys-
tems: 1) sand  and gravel deposits in the  glacial drift; 2)  shallow
dolomite formations; 3) the Cambrian-Ordovician aquifer; and 4)
the Mt. Simon aquifer. For  purposes of this report,  the sand and
gravel deposits and the dolomite formations are  collectively re-
ferred to  as the  shallow aquifers, while the  Cambrian-Ordovician
aquifer is referred  to as the deep sandstone aquifer.  The Mt.
Simon aquifer is considered separately and  discussed to  a lesser
degree because it is virtually unused at present.  While there are
several surface streams flowing through the region, only the Kan-
kakee River has been seriously considered  as  a source of public
water supply.

2.02 LAKE MICHIGAN   Lake Michigan is the most extensively
used water source.  It provided 1,105  million gallons  per day
(MGD) for public water supply in 1970, or about 85 percent of
the region's total public  water supply needs. (1)  From a purely
physical standpoint, the Lake offers an almost limitless amount of
water that can be  readily  treated  to acceptable  drinking water
                                                                  quality. It should be noted that no  water  flows naturally from
                                                                  the Lake to the region. That which is  withdrawn for water supply
                                                                  and other  purposes  constitutes a diversion.  Currently, this diver-
                                                                  sion is limited to 3,200 cubic feet per second  (cfs), or about 2,OHO
                                                                  MOD, as a result of a 1967 U.S. Supreme Court  Decision.

                                                                    The City of Chicago is the largest user of Lake Michigan water,
                                                                  withdrawing amounts to meet its own needs as  well as those  of
                                                                  72 suburban communities in Cook County which purchase water
                                                                  under contract.  Additional  water is withdrawn by fourteen other
                                                                  public  water supply  systems located  along the Lake Michigan
                                                                  shoreline in Cook and  Lake Counties; service  by those  systems
                                                                  is usually limited to one or  two communities.  Given the expected
                                                                  future development of the region, coupled with decreased  ground-
                                                                  water availability in certain areas, the Lake will be  more heavily
                                                                  relied upon for public water supply in the future.
                                                                  2.03 SHALLOW  AQUIFERS  The  shallow  aquifer system  in
                                                                  northeastern  Illinois is  comprised of  unconsolidated  sand and
                                                                  gravel deposits of the glacial drift and dolomite formations, mainly
                                                                  of Silurian age.  Although these aquifers uu- hytlraulically  intci-
                                                                  connected, their characteristics are sufficiently different to warrant
                                                                  separate discussion.

                                                                  a. Sand and Gravel Aquifers  The sand and gravel aquifers ran-
                                                                  domly underlie approximately 50 percent of the  region at depths
                                                                  ranging  from near the land suifare in certain areas to more than
                                                                  400 feet in  others.  (Figure 2-1 is a  cross-sectional  illustration  of
                                                                  (l):flef. l.pg. 3
Figure  2-1
              The Groundwater Aquifers of
              Northeastern Illinois
                                                     GEOLOGIC
                                                                                              HYDROLOGIC
                    THICKNESS
                     (FEET!
                                                                                                        CRYSTALLINE HOCK

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the entire regional  aquifer system.)  Extensive surficial sand and
gravel deposits are  found  in  parts  of  DuPage,  Kane,  Lake,
McIIenry and  Will counties, while deeply buried deposits  are
found  widely scattered throughout Kane  and McHenry counties,
western  Lake County,  northeastern Cook and  DuPage counties
and central Will County.  Generally, the greatest chance for suc-
cessful well penetration of a productive water yielding sand and
gravel formation is  within subsurface valleys cut into the bedrock
by preglacial and glacial geological processes.

  Because  of their irregular occurrence, the  sand and  gravel
aquifers  are more difficult to locate than the deeper, more exten-
sive sandstone  aquifers.  They are also more difficult to develop
for large water supply systems since they are more directly affected
by the vagaries of rainfall  and  drought.  On the  other  hand,
the glacial drift aquifers are generally  more rapidly recharged,
are more permeable  than  the deep aquifers, and  involve  lower
drilling costs.   Locally  they  provide  good sources  of  supply  to
municipalities and private individual users, with  some wells  yield-
ing in excess of 1,000  gallons per minute  (gpm).  In 1970, ap-
proximately  31.4 MGD were pumped from  the sand  and gravel
aquifers in the six-county region.  This amounted to approximately
Figure 2-2  Area of High Yield from the
              Shallow Dolomite Aquifer
12 percent of the estimated total groundwater pumpage  in  that
year, which was 261.2 MGD.(2)

  The hardness content of raw  water is  extremely  variable but
usually ranges between 100 parts  per million (ppm) and 450 ppm.
The iron content which can affect the taste, appearance  and use
of water averages about 2  ppm  and  is higher than that of the
deep  aquifers and Lake Michigan.  Water temperatures average
about 52 degrees, which is considered to be cool and refreshing.

b. Dolomite  Aquifer  Underlying much  of the region at depths
varying from  ground surface to 450 feet deep  is the  shallow dolo-
mite aquifer.   In this aquifer  groundwater is  found in  joints  and
fractures, and  it moves through an  interconnected network of
these  openings.  Since these water-bearing cavities  are unevenly
distributed both  horizontally  and vertically,  the  yields of wells
drilled into the  dolomite vary greatly from place to place.  Suc-
cessful development  for water supply depends upon a  well inter-
secting a large, water-filled fracture which is capable of sustaining
heavy pnmpaije over time.  Some  .veils drilled into dolomite yield
in excess of  1,000 gpm, while others result  in very low yields.
Figure 2-2 shows the general area of highest yields  from  this
formation.

  The dolomite aquifer is  an extensively used  source of water
supply for many municipalities,  particularly  in  DuPage  County
and  southern and  northwestern   Cook  County.  In 1970,  total
pumpage from the dolomite was estimated at 90.7  MGD, which
was approximately 35 percent of the  region's  groundwater with-
drawal.(3) In several areas the aquifer is being pumped in excess
of recharge,  and there have  been significant declines in water
levels and well yields.

c. Estimates  of Potential Yield   Potential yield is defined  as the
maximum amount of water that can be developed from a  reason-
able number of wells and well  fields without creating critical water
levels or exceeding the rate of groundwater recharge. The Illinois
State  Water Survey has estimated the  potential yield of the shal-
low aquifers  (sand and gravel and dolomite  combined)  at  507
MGD,  assuming they  are fully developed  in  the  six-county
area.(4)  According to the  total shallow aquifer pumpage figures
noted above,  only 122.1 MGD were withdrawn in 1970. Thus, on
a regionwide basis, the shallow aquifers  are  currently  producing
only about 25 percent of their potential yield,  and there is greater
opportunity for  increased development of them for future water
supply.

2.04  CAMBRIAN-ORDOVICIAN  AQUIFER   The   Cambrian-
Ordovician (or  deep sandstone aquifer)  is regarded as the  best
bedrock  aquifer in Illinois  because of its consistently high yield.
It extends  continuously throughout  the region and  is uniformly
productive. This aquifer is actually  a vertical  series  of  water-
bearing rock  fonViations, of  which the  Glenwood-St.  Peter  and
Ironton-Galesville  sandstones  ure the  principal  producers.  The
latter is  considered to be the most productive and  supplies over
50 percent of the aquifer's total yield. Because this  aquifer has a
regional  southeasterly dip of  about 10 feet per mile,  the top of
the Ironton-Galesville sandstone lies about 800 feet below the land
surface in the northwest corner of the region  and increases to a
depth of about 1,800 feet in the  southeastern part. The saturated
thickness of  this aquifer varies  from  approximately 100  feet to
about 275 feet, while the avetage collective thickness of the geo-
logic  formations comprising the aquifer is about 1,000 feet. It is
significant to  note that while some recharge of the deep sandstone
                                                        l by
                                                   i Howion Eng«w*r*
(2):Ref. 2
(3): Ref. 2
(4): Ref. 3
                                                              E-2

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occurs in western  Kane and McHenry counties,  most takes  place
in areas outside  of the metropolitan region,  including  Kendall,
Boone and  DeKalb counties of  Illinois,  and in certain  areas  of
southeastern  Wisconsin.  It  is important  that future urbanization
and  land use  in  those areas  not  have an adverse impact on
recharge.

  The Cambrian-Ordovician aquifer is the most heavily pumped
aquifer in  the region;  it furnished  approximately 53 percent  of
the total groundwater used in 1970.  Since 1958, withdrawals from
this aquifer have exceeded  the practical  sustained  yield,  which is
defined as the  maximum amount of water which can be continu-
ously withdrawn from existing pumping centers without eventually
dfwatcring  the most productive  unit (i.e., the Ironton-Galesville
stundstone).   The  practical sustained  yield  of  the  Cambrian-
Ordovician aquifer has been estimated at only 46 MGD. Pumpage
data for 1970 indicates that actual withdrawals approximated 139
MGD, or about three times  the estimated sustained yield.(5) This
withdtawal of water at rates in excess of natural recharge (termed
"mining")  has been reflected by a  progressive  decline  in  water
levels, increased  pumping  lifts  and increases in  pumping  costs.
During the period 1966-1971, annual water level declines in wells
in the Cambrian-Ordovician aquifer averaged nine feet.

  Table 2-1 lists the increases in pumpage from  the deep  sand-
stone aquifer during the period  1966-1971.

TABLE 2-1:  PUMPAGE FROM DEEP WELLS IN NORTHEASTERN
             ILLINOIS, 1966-1871 (IN MGD) (6)
Public
Supplies
County
Cook
DuPage
Karm
Lake
McHenry
Will
Total Region
1966
31
11
23
2
2
12
81
1971
42
16
26
5
2
14
105
industrial
Supplies
1966
24
1
3
1
1
16
46
1971
17
1
2
2
1
14
37
Total
1966
55
12
26
3
3
28
127
1971
59
17
28
7
3
28
142
 While industrial pumpage declined over the five-year period, total
 pumpage actually increased  15 MGD as a result of greater with-
 drawals for public supply. Particularly noticeable are the increases
 in public pumpage in Cook and DuPage counties.

   Despite  the problem  of overpumpage, the Cambrian-Ordovician
 aquifer will continue to be an important source of  supply. Water
 in this system is naturally free of bacterial pollution. The hardness
 content is from 200 to 250 ppm in the northwest part of the region,
 and increases toward the east as the aquifer increases in depth.
 The iron content of the water is usually less than 0.4 ppm. Tem-
 peratures range from 54 to about 62  degrees  and  increase with
 depth. The Cambrian-Ordovician aquifer  is generally well  suited
 for large, municipal water systems;  yields in excess of 1,000 gpm
 have been  recorded. Mining of this aquifer cannot be continued in-
 definitely.  Eventual provision must  be made for  transfer  to  an
 alternative or supplemental source in areas where water levels and
 well yields are declining.

 2.05  MT.  SIMON AQUIFER  The Mt. Simon aquifer  underlies
 the Cumbrian-Ordovician system and is the  deepest in the region.
 The top of this aquifer ranges from 1,400 to 1,600  feet  below the
 ground surface in the northwest, and from 2,200 to 2,400 feet in
 the  southeast.  Its average thickness is  approximately  1,600 feet,
 with the  materials consisting primarily of fine to  coarse grained
 sandstone.  The cleaner parts of the sandstone yield moderate quan-
 tities of water,  although the aquifer's  potential  is  limited by  a
number of factors. The most significant limitation i, ' ..nkish watt
beginning at depths below 1,300 feet mean sea le\u, necessitating
costly treatment prior to use. The  aquifer also is not consistently
permeable. Furthermore, deep and expensive wells are involved,

  The practical sustained yield of the Mt.  Simon aquifer has been
estimated at 14 MGD, although development of this  -ource  ha
been virtually nonexistent to date. In 1973, the Illmoi" State Watei
Survey  completed a feasibility study of developing a-n. desalting
water from  the Mt.  Simon  aquifer. Reverse  osmosis  ,MH\ freezin"
processes were considered feasible  for 1 MGD cap.'       .ihnon;
plants, while distillation was considered feasible fc><  .  ,n i > pl:,i ts
Costs (including  wells, transmission  lines, desalting (,i> i ';<-s  ai-
brine disposal) ranged from  $1.33/1,000 gallons  fo<    \  \!< .
reverse  osmosis plant to $1.85/1,000 gallons for a 5 M'  •  1,   ,<
tion plant.

2.06  SURFACE  WATER RESOURCES  Unlike man    .lur Ian;.
metropolitan areas, no inland  lakes, rivers  or streams are presei
used  for public water  supply in  northeastern  Illinois. There >
however, substantial industrial use  of water from the S.imtary  ,n,i'
Ship  Canal,  the Calumet River, the Des  Plaines River and,  to ,1
lesser extent, the Fox River.

a.  Limitations  There  are  several factors which  have mitigated
against the  use of surface watercourses. Certainly one reason (at
least  until  recently)  has  been  the  readily available supply of
groundwater which could be developed at low cost. But the major
deterrent has been the general poor quality of the region's surface-
waters,  a problem which  necessitates  thorough,  expensive treat-
ment. While water treatment technology has advanced to the point
where virtually any  water can be made potable, the cost of such
treatment may be excessive,  especially when compared with  tin-
cost of  developing alternative sources. Waterways such as the  Des
Plaines  River have been discounted as viable sources of municipal
water supply because of their lack of dependable flow, high  con-
centrations of bacterial  and viral organisms, high solids and heavy
metals  content, and  undesirable tastes  and odors.

  Nevertheless, the suitability of these waters should be periodi-
cally  reevaluated in  light  of changing needs  and conditions.  As
improved methods of wastewater treatment are  employed and as
nonpoint sources  of pollution  are reduced, surface waterways  may
become economically feasible and  attractive water sources.  In the
interim, greater attention could be  given to increased use of these
waters  for non-domestic purposes  whenever possible  in  order to
alleviate competitive  pressures on water resources which are  suit-
able for public supply.

b.  Kankakee River   It should be  noted that the Kankakee River
is an  exception to the foregoing  discussion  and  does offer potential
for development as municipal  supply. The river's raw water quality
is reasonably good, and its large flow volume would eliminate the
need  to construct expensive  storage reservoirs. In addition,  it is
proximately located to the Joliet area where there is concern for
the long-term availability of groundwater.

c.  Fox River  At the present time it is not advisable to  use the
Fox River for domestic purposes  since a high percentage of its
flow consists of wastewater treatment plant effluent which presents
a risk of  viral or chemical contamination. (7)  However, the  Fox
River may offer some potential for future use  as  a  public water
supply. Indeed, state water quality standards have designated the
river  for "domestic and food processing water supply," and pollu-
(5): Ref. 2
(6): Ref. 4, pg. 8
(7): Ref. 5
                                                                E-3

-------
tion  abatement efforts necessary to achieve that standard are un-
derway. After the desired level of water quality has been attained,
the river might be  used for this  purpose. One possible approach
would be to reduce deep well pumpage in the Fox Valley area to
the rate which can  be sustained without mining. Demands which
could not be satisfied by groundwater under this  condition  could
be compensated for through withdrawals from  the river. During
seasonal low streamflovvs, well pumpage could be increased beyond
sustained  yield  on  a  short-term basis  until  normal  flows  are
resumed.

') percent) wre  taken from  the deep sandstone aquifer, 36.4
MOD (36 nru-ent)  from  the dolviuti-.  and 3.7 MOD (4 percent)
from the  sh.iilow sand and gravrl

   Deep sandstone pumpage in  Cook Count j is  more  than  twice
'hat in any  other northeastern  Illinois  county. Water  well levels
 have declined in response to heavy drawdowns, particularly in the
northwest and southern portions. There is also significant pumpage
from the shallow   aquifers,  especially   in  the  southern sector.
Chicago  HeighK, and to a lesser  extent  LaGrange,  have  been
 identified as ,ue;is where pumpage has exceeded recharge. County-
    le, the i ' >;.!'<>u  01 allow aquifer potential yield is 98  MGD.
2.09 DU PAGE COUNTY  DuPage  County  is supplied exclu-
sively with  groundwater, and  pumpage  in  1970 averaged  51.7
MGD. The dolomite accounted for 33.9 MGD of the total with-
drawal (66 percent), while the  deep sandstone  yielded 15.5 MGD
(30  percent)  and  the  sand and gravel aiiiifers  2.3 MGD  (4
percent).

  There  is considerable concern for the long-term adequacy of
groundwater  supplies in DuPage County.  The potential  yield of
the sand  and gravel and  dolomite aquifers  is estimated at  42
MGD and by 1972, pumpage from these aquifers had increased to
39.7 MGD.  In  some  areas  (most  notabiy  in the  vicinities  of
Hinsdale, Clarendon  Hills, Addison,  Downers Grove,  Wheaton
and Glen Ellyn) the dolomite is  already being pumped  in excess
of recharge, and there has  been permanent lowering of the water
table and reductions in  well yields.  In  an effort to compensate for
these declines, increased numbers  of  deep sandstone wells  have
been drilled.  Extensive mining is being practiced, and water levels
in the deep wells have been declining steadily for several years.

2.10 KANE  COUNTY  Kane  County  is supplied  primarily with
groundwater, although  there is some minor  industiial use of the
Fox River. The  western two-thirds  of  the  < ounty is largely rural,
and  no  particular water supply problems  are  being  experienced.
However, in  the  more urbanized  Fox  River Valley urea,  the
Cambrian-Ordov ician aquifer  i;>  heavily used, and  steady water
level  declines have been  observed,  particularly  in  Aurora  and
Elgin.

   The importance of the deep sandstone aquifer is illustrated by
the fact  that it  provided 27.9  MGD (or 74  percent)  of  the 37.5
MGD total  pumpage m 1970.  The sand ami  gravel and  shallow
dolomite aquifers produced 6.2 MGD (17  peicent) and 34 MGD
(9 percent)  respective^ Theii potential yield is estimated i«s 31
MGD, which is  the lowest of the six counties.

2.11  LAKE  COUNTY  Lake  Michigan is the primary  source of
supply in eastern Lake County, while  groundwater is used in the
central and western portions. In ter ns  ot total groundwater pump-
age, development  of  the  three aquifer  systems  has been ap-
proximately  equal.  According to  1970  pumpago  figures,  with-
drawals amounted to approximately 19 MGD. The sam! and giiivel
aquifers  produced 69 MGD (36 peu-ent) of  the  total,  followed
by 6.1 MGD (32 percent) from the dolomite  and 6.0 MGD (32
percent) from the deep sandstone.

   Water  level declines in the deep wells are being  cxpei wnced
in certain areas  (primaiily Libertyville and Mundelein),  although
this situation is not  as  severe  as that  in  Cook and  DuPage
counties. There  appear to be considerable opportunities for greater
development of  the  '-hallow aquifers, where potential yield is esti-
mated at 51 MOD.

2.12  MC HENRY COUNTY  Of  the six counties, McHcnry is in
the most favorable position with respect to water supply  The sand
and gravel aquifers are by fur the predorniniiiit .source  and their
use  is increasing. They supplied  9.4 MGD (or 63 petccnt) of the
county's 15 MGD total pumpuge in 1970.  R\ \va\ of contrast, the
deep sandstone  produced 3.0 MGD (20 peicent) and the dolomite
produced 2.6 MGD (17 percent).

   It is significant that the  combined potential yield of the shallow
aquifers is estimated at 96 MGD. Thus, while the shallow aquifers
provided 12 MGD (or 80 percent)  of McHenry County's  total 1970
 groundwater demand, this still amounted to only about 13 percent
of the  total quantity potentially available to the area  from  the
 shallow  system.
                                                              E-4

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                                                                     APPENDIX  F
raising Lakes  Michigan and  Huron  by 4.4 inches,  excluding  the
effects of  the  Illinois diversion.  The effect of the present Illinois
diversion  (exclusive of the diversion  into  Lake  Superior)  is  to
lower Lakes  Michigan and Huron 2.7 inches  The net effect  of
these m-and-out diversions is to  raise the  levels of Lake Michigan
and Lake  Huron by 1.7 inches. To put this in perspective, artificial
diversion  into the  Great  Lakes presently  exceeds diversion out  of
the Lakes by  approximately  1,800 cfs. It therefore  would appear
that  diversion by  Illinois could  be increased  without having any
critical effect  on the Great Lakes Basin as a whole. Indeed, such
.111 increase would ullow n  better inflow-oiitllow  balance  to  be
achieved.


SECTION  C

Groundwater Mining
8.12  GENERAL  There are two basic approaches to groundwater
development.  The first regards  aquifers only as systems through
which water moves, and favors  limiting  well withdrawals to  the
practical sustained yield.  The second approach, mining, favors con-
tinued withdrawal of  water from the aquifers  at  a rate  which
exceed, that of rechaige At the present time, approximately  96
MCD ;,'f UK- 1)2  MGD pumped from the deep sandstone aquifer
in tins icgion  arc mined.

fc.l.'i  ADVANTAGES  AND DISADVANTAGES   Mining is  a  de-
but.ihlc ISMH-.  The most common argument against the practice
l/eneialiy  li.\s  been *h;it since it  removes  water held in storage, it
deprives future generations of the light to obtain adequate water
at i<",v i ost Tiie extension of this icasoning is that present punipage
illicit I-] be icduced to sustained yield, with any deficiencies  to  be
made up thioiigli the development of alternative supplies, including
u'uiote suif.iee souices In tins way, water held  in aquifer storage
uuiild he kept iii pfiiiianent tuist  for future  use.  The counter
urgMiiifnt  in favor of mining is  that the water in  storage is  of  no
value' unless  it is  used  In nddition,  mining  allows large capital
investments in smtate water supply projects  to be deferred to a
later date. In the  jiteiim, changing technologies and alterations in
watei use  patterns conceivably could reduce the need for importing
large quantities of water.

  One of  the cential objectives of water management is to provide
adequate  service with  the maximum net benefit to all. Clearly, if
the same  benefits  can  be  deuved from any of several alternatives,
t!n> least  cost alternative will result in the maximum net benefit.
Since the cost of mining  water is usually less than  the cost of
obtaining  water from  an outside source, it follows that mining
may need to be conducted until it is  no  longer economically fea-
sible, at winch time the  next "lower  cost" source  would be  de-
veloped.

  There are  a number of other  reasons why mining of the deep
sandstone  aquifer might be continued on a managed basis in north-
eastern  Illinois  First, if mining were not practiced  and  with-
drawals were  limited to the  rate  of recharge, a  number  of
townships m  the  region  would  become deficient in groundwater
by  1980  Given existing legal  limitations  on  diversion  of  Lake
walei. these  deficiencies  could not easily be satisfied by importa-
tion   froi.i that source.   Furthermore, considering  the existing
investment in  wells and pumping facilities, coupled with the large
amount of water  held  m aquifer  storage, it may  be expedient to
continue or accelerate mining, at least on  a short-term basis.  It
should also be noted that the dewatermg of the aquifci as a  result
of mining probably  would  not cause  serious   damage  to  the
aquifer's water storage or transmitting properties. Indeed, if after
a period  of mining, pumpage were reduced to  sustained  yield,
water levels would rise and the capacity of the aquifer to transmit
water would eventually return to  its original state.
Water Conservation, Recharge, and Recycling

8.14 GENERAL  One means of helping to avert water shortages
is to institute water conservation and/or reuse and recycling tech-
niques.  Conservation measures employ  technical, economic, educa-
tional or legal  tools to control water  usage in such  a way  as  to
balance  it with  supply  Recycling seeks  to  maximize  the use
potential of any  given quantity ol  water. The primary objective
of both of these approaches is  to  manage existing sources  more
efficiently and  effectively  as  an alternative  to  developing  new
sources.

8.15 WATER   CONSERVATION   TECH'.I'. j£S   A  detailed
discussion of water conseivation  (particular)  •'>mestic conserva-
tion techniques)  is contained in Appendix E  T!i   which follows
is  primarily concerned with water metering ana  leakage control
with brief attention given to  reduction of  in-house  \v iter  waste

a.   Metering   Metering water consumption is  one nethod  of en-
couraging thrift and normalizing water demand  m a community.
Metering allows consumers to be charged according to the amount
of  water they  use,  thus  providing  an economic  incentive  to
minimize waste. For example, greater use of meters has been cited
as a contributing factor to the reduction in per  capita consumption
in the  City of Chicago, where  average water use decreased from
302 gpcpd in 1930 to 249  gpcpd  in 1972.

  Metering is regarded as one of the most fundamental precept-,
of  modern water management. Yet.  .» number  of public vatci
systems in the region do not  meter  consumption and prefei  U.
charge a flat rate for water provided  regardless of the amount u  -:3
With a flat rate sysloiu  in operation, theie  is virtually no  eco-
nomic  incentive for  consumers to practice water conservation

   It must  be iccognized that  the  cost of purchasing, instullir,1'
maintaining and  reading water meters is  substantial  Thus, it  m
not  be economical  to  meter  all water  users  that arc presently
unmetcred, particularly in light of the  relatively low rates chaiged
for water  in most communities. However, as water  become',  a
mou: valuable  resource in  the future, greater metering  (at  U as!
of new and large users) will probably be practiced.

b.  Control of  Leaks   Leakage from  water distribution systems
can create a substantial demand on water supplies  without  pro
viding any corresponding benefits  Excessive leakage reduces the
amount of water available for domestic purposes and  increases
overall  costs. A number of factors  influence leaks, including  age
of the  system; maten'als used m construction; physical and chem-
ical properties  of the  soil;  properties  of the  water,  pressures in-
volved; and the degree of proper maintenance.

  While no  system  is absolutely  tight and  some  leakage  will
inevitably occur, leaks should be reduced to the greatest practical
degree. In the  construction of new distribution facilities or in the
replacement or addition to  older facilities, leakage control can  be
achieved through proper sealing of  joints and testing  for tightness
Control in existing systems can be  achieved through an ongoini'
detection and correction  piogram.  However,  the  savings deuved
from such a  program must be  balanced against  the costs of  its
operation. Total elimination is seldom  justifiable economically, bin
it can proceed to the point where the cost of salvageable water Sost
equals the cost of a repair  program. Any additional rehabilitation
beyond this point would not be economical since the cost of repair
would  exceed  the incremental  benefits  derived  from the water
savings.

  The appropriate magnitude  of a leakage detection and repan
program is thus  dependent upon  a number of factors, the most
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important of  which art'  the  rate  of  loss of  salvageable water
within the system, the cost  of  supplying  water;  and the cost of
system maintenance and repair.  Individual communities contem-
plating a  leakage control program should evaluate their particular
systems in light  of these  conditions to determine the extent of
corrective' ailion warranted  Those  having serious leakage prob-
le-rm  nuv Ix-nefit coiisider.ibly from  increased  water  savings,
especially if  water costs are high or  supply  is inadequate. Con-
veisely, communities that ha\e relatively minor leakage problems,
low water costs ancl abundant supplies probably need not under-
take extensive  coutiol programs.

c.  Water Conservation in  the Home  Several steps can be taken
to reduce  water consumption uiuKoi  waste  in and around  the
luiine. Maintenance am!  lepair  of  leaky  plumbing  fixtures  can
s.i\e huge quantities of water over time which otherwise would be
lost  Use oi water conserving devices such as shallow trap toilets,
washing  machine  "suds savers"  and restricted How showerheads
can also reduce  in-house  witer consumption.  Substantial reduc-
tions  can  also lie ellettcei by taking care that lawns arc not over-
wateied ami  that  too  much  water is not  used  for such activities
as washing automobiles Conscious  efforts to  eliminate  waste  not
only  < onsen c  water  but also  result in economic savings in  the
form  of reduced watei  bills.

8.16  ARTIFICIAL   RECHARGE  Intensive  development   of
Hunmdw.itei  lias  ricafed considerable  interest in the possibility of
.ntiliciaUy  ice-barging  the  aquifers   Replenishment of water in
,'reas  of concentiated punipage. it feasible, would  reduce  the rate
ft \\atei  level decline  and improve the yield  capacity  of wells.
( Vusequently,  the ines of existing wells could be prolonged  and
the aquifer could  continue to provide  a  dependable water supply.

n. Sources of Recharge Water  The most  readily available source
ot watei  for uitificia! recharge  i,s the seasonal  high flow in surface
>h earns.  The  diversion of high  flov,s  from  stream channels  foi
aitificial  recharge would also make available  additional storage
space in  these channels for the temporary stoiagc of flood peaks.
Sophisticated stormwater diainage systems piovide efficient means
foi the collection and  tempoiaiy detention in  basins of water that
also cini  be nstd for  aitificial icch.irge of  the shallow aquifers. If
the1 highy polluted initial Hush from urban areas  is bypassed,  the
rein.lining stonnwater, if treated, may be suitable  for artificial re-
cli.iryc  However,  the  feasibility  of this  technique' needs to  be
moie  thoioughly  investigated. Other possible .sources include cool-
ing water, certain industrial waste-waters, and conceivably, treated
domestic wastewater.

b.  Methods   The  three principal methods of  direct artificial re-
charge  are  water  spreading,  seepage  pits   and  injection wells
Induced infiltration from streams caused by pumpage from nearby
wells is  an mcliiect method of artificial recharge. Whatever  the
method,   artificial  recharge  icquije.s  agencies and facilities   to:
obtain, treat  (if necessary) and transport the; water to the recharge
aiea,  mfiltiate or inject the \vatei, and provide for the disposal of
any excess water.  The  development of the area affects the capital
cents  of  the-  project. High land costs in  the urbanized  parts of
the region faven  the  use  of  the  pit  and  injection well methods
which icquire less land. Spreading basin methods require more
land  and  would more likely be used in rural areas. Economics  will
slrongK influence the; degree to which artificial it-charge operations
ait initialed  in the* future.

e.  Potential  Recharge Areas  The Illinois State Water Survey has
identified ten areas in  northeastern  Illinois which  would probably
!»• suitable for the pit method of artificial recharge. These areas
\vcie selected because,  there was a well-defined cone of depression
in the water  level suitace of the aqmfei  under consideration; there
was a suificial sand and gravel  deposit in  the area, and there  was
a perennial stream  in the immediate vicinity  to seive as a ..)• i
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Figure 8-1   Prime Natural Recharge Areas in Northeastern Illinois
                                                                                                      scale  in miles
       Based on information provided by the
       Illinois State Water Survey
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realistic alternative in northeastern Illinois, at least in the immedi-
ate future. It is true that sophisticated methods of waste treatment
are presently available which allow near total reduction  in the
biological and chemical contaminants of wastewaters. When thus
purified, the effluent is suitable  for industrial  or agricultural pur-
poses.  However, the cost of such treatment,  when  coupled with
health concerns and probable aesthetic objections, does not pres-
ently favor the use of recycled  wastewater for municipal supply.

   During 1973, this Commission reviewed two separate but related
applications for federal funds which involved testing  the feasibility
of recycling wastewater effluent for use as potable  water supply.
The  applicants  were the Village of Bensenville and the Hinsdale
Sanitary District, both  of  which are located  in  eastern DuPage
County where there is  considerable concern for the adequacy of
local groundwater supplies. The basic  concept of both these pro-
posed research  and development projects  involves the incineration
of municipal solid waste to produce heat, which can then be used
to distill treated wastewater plant  effluent. Depending upon the
outcome of test results, the distillate  could be used to  directly
augment present water supplies or to  increase local groundwater
recharge.  Both projects  are presently being reviewed  by the
USEPA. Their futures are uncertain at this time due to the paucity
of federal funds for projects of this nature.


SECTION  E

Organization and Administration

8.19 FRAGMENTATION  Perhaps the  most conspicuous  short-
coming of  the  present institutional  framework for  water  supply
is  the  extensive  fragmentation of  authority  and  responsibility.
Several federal, multi-state,  state, regional, and  county agencies
conduct specialized  programs which have significance  in  water
supply  planning and management.  At  the local operational level,
there are approximately 260 municipalities and numerous  special
purpose districts which are empowered to furnish water and en-
gage in related activities. Then,  too, there are  a number of private
utility   companies  authorized to  provide  water,  principally  in
subdivisions and other  unincorporated areas.

   At the present time,  this Commission is the only  governmental
unit conducting a  comprehensive  water resources  management
planning program in the six-county northeastern Illinois  region.
On the operational level, the trend continues  toward the creation
of more separate and independent systems which deal with prob-
lems on a piecemeal basis.  Waterworks have been constructed and
expanded without benefit  of areawide planning,  coordination or
controls. Slight attention has been paid  toward developing a water
supply  system for the region as a whole, with the view of pro-
viding  for  needs beyond the immediate  future.  Instances  of co-
ordinated, interlocal efforts have been few. Indeed, there are cases
in which there has been keen competition between communities for
available water, a situation which has at times interfered with the
optimum development of the resource.

   There are, of course, examples  of successful intergovernmental
cooperation. The arrangement by which the City of Chicago pro-
vides water to suburban Cook  County communities is  the most
notable. Some  of the  lakeshore communities north  of  Chicago
provide water  to  neighboring inland  municipalities on a similar
though more limited basis. There are also four public water com-
missions or districts  which  were organized  for the purpose of
obtaining and  furnishing water to customer  municipalities on  a
sub-regional scale.

   The  Great Lakes Basin  Commission  has noted that although it
may be difficult, more  emphasis should be put forth in developing
plans  for areawide utilities  and cooperate efforts. (15)  Problems
such  as  well interference  could  be  solved  by  preventing the
proliferation of small water systems while favoring larger utilities
which cross  corporate  boundaries  and  which  develop the  best
available source of water rather than  relying heavily on wells  in
the immediate area.  The GLBC recommends  that the preparation
of such plans, before population pressures and increased water use
necessitate independent crash programs, should begin immediately
and be worked out with local, county  and regional planning com-
missions.  Implementing plans  for  areawide utilities  may  require
the creation of additional laws .ind  regulations.

   The most  pressing future water supply need  will  be  that  of
providing adequate substitute sources for  those areas of the region
where groundwater deficiencies arr expected  to occur. Given the
fact that the areas of projected shoitage are jsenerallv located some
distance  from  Lake  Michigan, it  is  not i<>asil>K. tor  individual
municipalities to construct their own  independent systems.  Some
type of multi-community approach  may have to !>t Liken m order
to achieve economies of scale  arid  to minimize conilicts and in-
efficiencies.

8.20  ORGANIZATIONAL  ALTERNATIVES   There  arc several
alternative organizational structures which might be established for
this purpose, varying both in scope of authority and area of juris-
diction. A number of these possible  alternatives are highlighted
below to illustrate the  range of management opportunities  avail-
ble.

a. Maintain Existing Arrangements  This is a continuance of the
status quo in which no  major changes  in agency structures or pre-
rogatives  would be effected. Water supply development and use
decisions  would  continue to be  made  at  local levels, generally
without  regard  for broader area needs  and  problems.

   Water supply has traditionally been viewed  as a local  respon-
sibility, and  attempts to drastically alter this approach may not
withstand the test of implementation. Therefore, expansion and
coordination  of  the water supply programs of existing local  units
may be the most politically feasible and realistic method for deal-
ing with water supply problems on a regional scale. The potential
for duplication  of effort, waste  of funds, arid competition and
conflict would remain.

b.  Metropolitan Water Authority  At  the opposite  end  of the
institutional spectrum would be the creation of a six-county metro-
politan water authority. If  authorized, this agency would assume
primary  responsibility for furnishing water on a "wholesale"  basis
throughout  the  region, or  for significant portions thereof where
economies of scale might  favor  such  an arrangement.   Source
development, treatment,  and  primary   transmission   would fall
within its purview.  Individual  municipalities would  retain  re-
sponsibility for  constructing and operating local  distribution and
storage systems.

   It  would  also  be possible  to  expand the role  of  the  water
authority to  include  other  important aspects of  water resources
management.  This  has been  done in  the Detroit  metropolitan
area  where a single  agency was  created to  deal with the water
supply, wastewater, and stormwater drainage problems of  Detroit
and 88 neighboring municipalities.  With respect to  water supply
alone, significant  cost sailings  have been realized as  a result  of
the metropolitan utility approach.

   Such an agency would allow for the systematic expansion and
operation of all public water facilities in the region.  It would of
course be necessary  to base such  functional program on a  com-
prehensive  plan for the region to ensure orderly  and  efficient
growth and  development.  Other  issues  requiring careful  consid-

(15): Ref. 9, pg. 278
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