EPA-600/2-78-043a
March 1978
Environmental Protection Technology Series
                PRETREATMENT OF  THE  COMBINED
         INDUSTRIAL-DOMESTIC WASTEWATERS OF
                         HAGERSTOWN,  MARYLAND
                                           Volume I
                           Rot
                                  Office of Research and Development
                                 U.S. Environmental Protection Agency
                                         Ada, Oklahoma 74820

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                RESEARCH REPORTING SERIES

Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology.  Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:

      1.  Environmental  Health Effects Research
      2.  Environmental  Protection Technology
      3.  Ecological Research
      4.  Environmental  Monitoring
      5.  Socioeconomic Environmental Studies
      6.  Scientific and Technical Assessment Reports (STAR)
      7.  Interagency Energy-Environment Research and Development
      8.  "Special" Reports
      9.  Miscellaneous Reports

This report has  been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.

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                                       EPA-600/2-78-043 a
                                       February 1978
PRETREATMENT OF THE COMBINED INDUSTRIAL-DOMESTIC
      WASTEWATERS OF HAGERSTOWN, MARYLAND
                    Volume I
                        by

                 David S. Kappe
             Kappe-Associates, Inc.
           Hagerstown, Maryland 21740
             Project No. 11060 EJD
                Project Officers

             Harold J. Snyder, Jr.
                 Marshall Dick
       Office of Research and Monitoring
     U.S. Environmental Protection Agency
            Washington, D.C. 20460
ROBERT S. KERR ENVIRONMENTAL RESEARCH LABORATORY
        OFFICE OF RESEARCH AND DEVELOPMENT
      U.S. ENVIRONMENTAL PROTECTION AGENCY
              ADA, OKLAHOMA 74820

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                               DISCLAIMER
     This report has been reviewed by the Robert S. Kerr Environmental
Research Laboratory, U.S. Environmental Protection Agency, and approved for
publication.  Approval does not signify that the contents necessarily re-
flect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
                                      ii

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                                  FOREWORD
     The Environmental Protection Agency was established to coordinate
administration of the major Federal programs designed to protect the
quality of our environment.

     An important part of the Agency's endeavors to fulfill its mission
involves the search for information about environmental problems, manage-
ment techniques and new technologies through which optimum use of the
nation's land and water resources can be assured.  The primary and ulti-
mate goal of these efforts is to protect the nation from the scourge of
existing and potential pollution from all sources.

     EPA's Office of Research and Development conducts this search through
a nationwide network of research facilities.

     As one of these facilities, the Robert S. Kerr Environmental Research
Laboratory is responsible for the management of programs to:  (a) investi-
gate the nature, transport, fate and management of pollutants in ground-
water;  (b) develop and demonstrate methods for treating wastewaters with
soil and other natural systems; (c) develop and demonstrate pollution con-
trol technologies for irrigation return flows; (d) develop and demonstrate
pollution control technologies for animal production wastes; (e) develop
and demonstrate technologies to prevent, control or abate pollution from
the petroleum refining and petrochemical industries; and (f) develop and
demonstrate technologies to manage pollution resulting from combinations
of industrial wastewaters or industrial/municipal wastewaters.

     This report is a contribution to the Agency's overall effort in ful-
filling its mission to improve and protect the nation's environment for
the benefit of the American public.
                                       William  C.  Galegar,  Director
                                       Robert S.  Kerr  Environmental
                                          Research Laboratory
                                      iii

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                                ABSTRACT
The sewage treatment plant of the city of Hagerstown, Maryland—a
manufacturing city with about 130 industrial  firms, which are classified
in more than 25 different product categories—receives for treatment
domestic sewage and a diversity of industrial waste and process waters.
Some of these industrial wastewaters exert high immediate and ultimate
oxygen demands that could not be satisfied by the treatment plant or
were otherwise detrimental to the biological  treatment processes of the
treatment system.  Therefore, certain methods of "pretreating" the city's
combined wastewaters to render these waters, more amenable to treatment
by the existing treatment plant were tried and evaluated.  The pretreat-
ment methods tested were intended to assist the plant in meeting the
oxygen demands by providing initial  oxidation.  The methods were: diffuse
aeration with and without the addition of waste activated sludge,
chlorination, addition of sodium nitrate, and the addition of potassium
permanganate.  Ammoniation was also  tried in  an effort to destroy some
of the more noxious industrial materials in the wastewaters.  Both
aeration and chlorination proved to  be effective methods of pretreatment,
with the efficacy of aeration being  enhanced  somewhat by the addition of
waste activated sludges.  Both methods increased the BODg removal
efficiency of the plant under dry-weather conditions from less than 70%
to better than 90%.
                                  IV

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                              TABLE OF CONTENTS
                                                                       Page
Abstract                                                                iii
List of Tables                                                          vii
List of Figures                                                         xiv
Acknowledgments                                                          xv
Sections
I.      Introduction                                                      1
        A.  Statement of the Problems and Objectives of Study             1
        B.  General Study Plan                                            3
II.     Conclusions                                                       8
III.    Recommendations                                                  10
IV.     The Project Site—The Hagerstown Water Pollution
        Control Plant—and the Project Facility                          11
        A.  Description of the Hagerstown Water Pollution
            Control Plant                                                11
        B.  Capacities of Existing Sewage Treatment Units                15
        C.  Project Modifications of the Hagerstown Water
            Pollution Control Plant                                      17
        D.  Project Facility                                             18
V.      Baseline Studies                                                 27
        A.  Preliminary Wastewater Analyses                              27
        B.  Survey of Industrial Plant                                   38
VI.     Studies of Various Pretreatment Methods                          69

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                       TABLE OF CONTENTS (continued)
        A.   Wastewater Analysis Schedule for Pretreatment
            Studies                                                      69
        B.   Startup and Stabilization of the Project Facility            69
        C.   Pretreatment by Plain Aeration and by Aeration
            and the Addition of Waste Activated Sludge                   76
        D.   Pretreatment by Addition of Sodium Nitrate and
            by Addition of Ammonia                                       82
        E.   Pretreatment by Addition of Potassium Perman-
            ganate and by Addition of Chlorine                           87
        F.   Pretreatment by Addition of Potassium Perman-
            ganate                                                       88
        6.   Pretreatment by the Select Method                            91
        H.   Sludge Dewatering Experiments                                93
VII.    Summary                                                          96
        A.   General                                                      96
        B.   Subsequent Work                                              97
VIII.   Reference                                                        99
IX.     Appendices  (Available  only  from  NTIS)
                                     vt

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                                 TABLES

No.                                                            Page

1.      Chemicals and Dyestuffs Consumed by the Florida         44
        Avenue Plant of the Potomac Dye and Printing
        Corporation

2.      Chemicals and Dyestuffs Consumed by the Franklin        48
        Street Plant of the Potojnac Dye and Printing
        Corporation

3.      Chemicals and Dyes Used by the Associated Ribbon        53
        Works

4.      Chemicals Used by Victor Hosiery Company                58

5.      Daily Chemical Useage of the Maryland Ribbon Conjpany    60

6.      Chemical and Materials Used by the W. H. Reisner        62
        Manufacturing Company

7.      Chemicals and Other Substances Used in Processes        66
        of the Breakstone Foods Plant

8.      Analysis Schedule for the Operational Studies           70

9.      Description of Sampling Points                          74

10.     Average Percent Removals of 6005, COD and Suspended     90
        Solids Achieved for the Four Two-Week Periods of
        the Study of Pretreatment by Chiorination

11.     The Decrease With Time in the Percent Moisture          95
        Content of Digested Sludge Placed on Sand Drying
        Beds in Various Layer Thicknesses

12.     Wastewater Flows and Temperatures Pretreatment by      112
        Aeration and Sludge Addition and Plain Aeration
        Treatment Systems A and B

13.     BODc Values of 24-Hour Composite Wastewater Samples    118
        Pretreatment by Aeration and Addition of Waste
        Activated Sludge Treatment System A
                                 vfi

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                           TABLES (continued)

No._

14        COD  Values  of 24-Hour Composite  Wastewater Samples    121
          Pretreatment  by  Aeration and  Addition  of Waste
          Activated Sludge Treatment System  A

15.       Suspended Solids Levels in 24-Hour Composite         124
          Wastewater Samples Pretreatment by Aeration
          and Addition of Waste Activated Sludge Treat-
          ment System A

16.       Hydrogen Ion Concentrations in 24-Hour               130
          Composite Wastewater Samples  Pretreatment by
          Aeration and Addition of Waste Activated
          Sludge Treatment System A

17.       Dissolved Oxygen Concentrations in Wastewaters        134
          Pretreatment by Aeration and  Addition  of Waste
          Activated Sludge Treatment System  A

18.       Hydrogen Sulfide Concentrations in Wastewaters        138
          Pretreatment by Preaeration and Addition of
          Waste Activated Sludges Treatment  System A

19.       Oxidation-Reduction Potentials of  Wastewaters*        142
          Pretreatment by Aeration and  Addition  of Waste
          Activated Sludge Treatment System  A

20.       BOD5 Values of 24-Hour Composite Wastewater          143
          Samples Pretreatment by Plain Aeration Treatment
          System B

21.       COD Values of 24-Hour Composite Wastewaters          146
          Samples Pretreatment Plain Aeration Treatment
          System B

22.       Suspended Solids Levels in 24-Hour Composite         149
          Wastewater Samples Pretreatment by Plain Aeration
          Treatment System B

23.       Hydrogen Ion Concentrations in 24-Hour Composite     154
          Wastewater Samples Pretreatment by Plain Aeration
          Treatment System B

24.       Dissolved Oxygen Concentrations in Wastewaters        158
          Pretreatment by Plain Aeration Treatment System B

25.       Hydrogen Sulfide Concentrations in Wastewaters        161
          Pretreatment by Plain Aeration Treatment System B
                               vm

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                          TABLES (continued)

No.                                                            Page

26.       Oxidation-Reduction Potentials of Wastewaters*       165
          Pretreatment by Plain Aeration Treatment System B

27.       Wastewater Flows and Temperatures Pretreatment by    167
          Addition of Sodium Nitrate and by Addition of
          Ammonia Treatment Systems A and B

28.       BOD5 Values of 24-Hour Composite Wastewater          172
          Samples Pretreatment by Addition of Sodium
          Nitrate Treatment System A

29.       COD Values of 24-Hour Composite Wastewater Samples   175
          Pretreatment by Addition of Sodium Nitrate Treat-
          ment System A

30.       Suspended Solids Levels in 24-Hour Composite         178
          Wastewater Samples Pretreatment by the Addition
         (of Sodium Nitrate Treatment System A

31.       Organic Nitrogen Concentrations in 24-Hour           183
          Composite Wastewater Samples Pretreatment by
          Addition of Sodium Nitrate Treatment System A

32.       Ammonia Nitrogen Concentrations in 24-Hour Com-      185
          posite Wastewater Samples Pretreatment by Addition
          of Sodium Nitrate Treatment System A

33.       Nitrite Nitrogen Concentrations in 24-Hour Com-      187
          posite Wastewater Samples Pretreatment by Addition
          of Sodium Nitrate Treatment System A

34.       Nitrite Plus Nitrate Nitrogen Concentrations in      190
          24-Hour Composite Wastewater Samples Pretreatment
          by Addition of Sodium Nitrates Treatment System A

35.       Dissolved Oxygen Concentrations in Wastewaters       193
          Pretreatment by Addition of Sodium Nitrate
          Treatment System A

36.       Hydrogen Sulfide Concentrations in Wastewaters       196
          Pretreatment by Addition of Sodium Nitrate
          Treatment System A

37.       Hydrogen Ion Concentrations in 24-Hour Composite     199
          Wastewater Samples Pretreatment by Addition of
          Sodium Nitrate Treatment System A
                                 IX

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                            TABLES (continued)

No.                                                            Page

38.       8005 Values of 24-Hour Composite Wastewater          203
          Samples Pretreatment by Addition of Ammonia
          Treatment System B

39.       COD Values of 24-Hour Composite Wastewater           206
          Samples Pretreatment by the Addition of Ammonia
          Treatment System B

40.       Suspended Solids Levels in 24-Hour Composite         210
          Wastewater Samples Pretreatment by the Addition
          of Ammonia Treatment System B

41.       Organic Nitrogen Concentrations in 24-Hour Waste-    215
          water Samples Pretreatment by Addition of Ammonia
          Treatment System B

42.       Ammonia Nitrogen Concentrations in 24-Hour           217
          Composite Wastewater Samples Pretreatment by
          Addition of Ammonia Treatment System B

43.       Nitrite Nitrogen Concentrations in 24-Hour           219
          Composite Wastewater Samples Pretreatment by
          the Addition of Ammonia Treatment System B

44.       Nitrite Plus Nitrate Nitrogen Concentrations         221
          in 24-Hour Composite Samples Pretreatment by
          Addition of Ammonia Treatment System B

45.       Dissolved Oxygen Concentrations in Wastewaters       223
          Pretreatment by Addition of Ammonia Treatment
          System B

46.       Hydrogen Sulfide Concentrations in Wastewaters       226
          Pretreatment by Addition of Ammonia Treatment
          System B

47.       Hydrogen Ion Concentrations in 24-Hour Composite     229
          Wastewater Samples Pretreatment by Addition of
          Ammonia Treatment System B

48.       Wastewater Flows and Temperatures Pretreatment       233
          by Addition of Chlorine and by Addition of
          Potassium Permanganate Treatment Systems A and B

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                            TABLES (continued)

No.                                                            Page

49.        BODs Values of 24-Hour Composite Wastewater         238
           Samples Pretreatment by Addition of Potassium
           Permanganate Treatment System A

50.        COD Values of 24-Hour Composite Wastewater          241
           Samples Pretreatment by Addition of Potassium
           Permanganate Treatment System A

51.        Suspended Solids Levels in 24-Hour Composite        244
           Wastewater Samples Pretreatment by the Addition
           of Potassium Permanganate Treatment System A

52.        Organic Nitrogen Concentrations in 24-Hour          248
           Composite Wastewater Samples Pretreatment by
           Addition of Potassium Permanganate Treatment
           System A

53.        Ammonia Nitrogen Concentrations in 24-Hour          250
           Composite Wastewater Samples Pretreatment by
           Addition of Potassium Permanganate Treatment
           System A

54.        Nitrite Nitrogen Concentrations in 24-Hour          252
           Composite Wastewater Samples Pretreatment by
           Addition of Potassium Permanganate Treatment
           System A

55.        Nitrite Plus Nitrate Nitrogen Concentrations in     254
           24-Hour Composite Wastewater Samples Pretreat-
           ment by Addition of Potassium Permanganate
           Treatment System A

56.        Dissolved Oxygen Concentrations in Wastewaters      256
           Pretreatment by Addition of Potassium Perman-
           ganate Treatment System A

57.        Hydrogen Ion Concentrations in 24-Hour Composite    259
           Wastewater Systems Pretreatment by Addition of
           Potassium Permanganate Treatment System A

58.        Manganese Concentration in Grab Samples Pretreat-   263
           ment by Addition of Potassium Permanganate
           Treatment System A

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                           TABLES (continued)

No.

59.        BODs Values of 24-Hour Composite Samples of         264
           Treatment Plant Influent and Effluent Pre-
           treatment by Chiorination Treatment System B

60.        COD Values of 24-Hour Composite Wastewater          267
           Samples Pretreatment by Addition of Chlorine
           Treatment System B

61.        Suspended Solids Levels in 24-Hour Composite        270
           Wastewater Samples Pretreatment by the Addition
           of Chlorine Treatment System B

62.        Organic Nitrogen Concentrations in 24-Hour          275
           Composite Wastewater Samples Pretreatment by
           Addition of Chlorine Treatment System B

63.        Ammonia Nitrogen Concentrations in 24-Hour          277
           Composite Wastewater Samples Pretreatment by
           Addition of Chlorine Treatment System B

64.        Nitrite Nitrogen Concentrations in 24-Hour          279
           Composite Wastewater Samples Pretreatment by
           Addition of Chlorine Treatment System B

65.        Nitrite Plus Nitrate Nitrogen Concentrations        281
           in 24-Hour Composite Wastewater Samples Pre-
           treatment by Addition of Chlorine Treatment
           System B

66.        Dissolved Oxygen Concentrations in Wastewaters      283
           Pretreatment by Addition of Chlorine Treatment
           System B

67.        Hydrogen Ion Concentrations in 24-Hour Composite    286
           Wastewater Samples Pretreatment by Addition of
           Chlorine Treatment System B

68.        Wastewater Flows and Temperatures Pretreatment      291
           by Chiorination (300 Ibs Cl2/day) Combined
           Treatment System

69.        BODs Values of 24-Hour Composite Wastewater         293
           Samples Pretreatment by Chiorination (300 Ibs
           Cl2/day) Combined Treatment System
                               xn

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                           TABLES (continued)

No.                                                            Page

70.        COD Values of 24-Hour Composite Wastewater          295
           Samples Pretreatment by Chiorination
           (300 Ibs Cl2/day) Combined Treatment System

71.        Suspended Solids Levels in 24-Hour Composite        297
           Wastewater Sample Pretreatment by Chiorination
           (300 Ibs Cl2/day) Combined Treatment System

72.        Total Chlorine Residuals in Wastewaters Pre-        301
           treatment by Chiorination  (300 Ibs Cl2/day)
           Combined Treatment System
                               xiii

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                                 FIGURES
No.                                                             Page

1.    Schematic Diagram of the Hagerstown Water Pollution        19
      Control  Plant

2.    A View of the Pretreatment Facility from the Head           24
      End of the Pretreatment Tanks

3.    A View across the Pretreatment Tanks of the Project        25
      Facility, Showing the Primary Settling  Tanks and
      Other Parts of the Hagerstown Water Pollution Control
      Plant in the Background

4.    The Project Facility immediately prior  to the Intro-        26
      duction of the Municipal Wastewaters into the
      Pretreatment Tanks

5.    Oxygen Demand Indices (GDI's) of Grab Samples of            30
      Primary Effluent Collected over the period of
      October 18 to October 24, 1967

6.    Photomicrograph of the Aeration Tank Mixed Liquors,        35
      Taken during the Baseline Study and Showing Fila-
      mentous Sulfur Bacteria Containing Globules of
      Sulfur and Growing among Masses of Zoogleal Bacteria

7.    Photomicrograph of the Aeration Tank Mixed Liquors,        75
      Showing New Fingerlike Growths of Zoogleal Bacteria

8.    Photomicrographs of the Aeration Tank Mixed Liquors,        78
      Taken during the Study of Pretreatment  by Addition of
      Sodium Nitrate and Showing Unidentified Filamentous
      Bacteria among Small Zoogleal Masses with much
      Adsorbed Inert Solids and the General "Burnt-Out"
      Appearance of Overage Sludge Resulting  from Excessive
      Recycling of Biological Solids in the Treatment Plant
                                xiv

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                           ACKNOWLEDGMENTS
This project was supported by the U. S. Environmental Protection Agency
through EPA Research, Development and Demonstration Grant No.  11060 EJD,
the State of Maryland and the City of Hagerstown, Maryland.

The Project Director wishes to express his deep appreciation to
Mr. Harold J. Snyder, Jr., who was the EPA Project Officer at the start
and through most of the project, for his much needed administrative
help and to Mr. Marshall Dick, who took over the duties of Project
Officer at the end of the project, for his patience and guidance in
the preparation of this report.

Also, special thanks are extended to the Honorable Herman L. Mills, who
was Mayor of the City of Hagerstown during the project and also the
Project Grant Administrator, for his sincere interest in and steadfast
support of the project program and the project team and to both
Mr. Robert E. Lakin, who, as President of J. B. Ferguson and Company,
had immediate responsibility for both the administrative and technical
aspects of the project, and Mr. Stanley E. Kappe, President of Kappe
Associates, Inc., for their invaluable guidance and engineering exper-
tise in the design and construction of research facility and in the
project studies.

Thanks are also due to Mr. James E. Eyerly, Superintendent of the
Hagerstown Water Pollution Control Plant during the project, for his help
in coordinating project activities at the project site and to his then
assistant and the present plant Superintendent Mr. Eugene Barnhart for
his outstanding assistance with the day-to-day operations and maintenance
of the pretreatment facility and with the on-site analytical program, and
to the laboratory technicians and plant operators of the Hagerstown treat-
ment plant for their fine efforts in carrying out the project program plan.

It is a pleasure to acknowledge, too, Dr. Charles E. Renn, Professor
Emeritus of Environmental Science Engineering, the Johns Hopkins
University and Research Associate of Kappe Associates, Inc., who
conducted the microscopic examinations of the plant biota, and
Mr. Dick C. Heil, Mr. Neil F. Kershaw and Mrs. Julia M. Patel,
engineer and chemists, respectively, of Kappe Associates, Inc.,
their exceptional engineering and analytical contributions to the
project.

In addition, the Project Director wishes to thank the industries that
were surveyed under the project for their superb cooperation and partici-
pation in the survey effort.
                                   xv

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                                SECTION I

                               INTRODUCTION


A.  Statement of the Problems and Objectives of Study

The City of Hagerstown, Maryland, with a population of over 35,000 persons,
is the  seventh  largest municipality  in the  state of Maryland.  It is a
manufacturing city with about 130 industrial firms, which are classified
in more than 25 different product categories.  These industries produce
such diverse products as aircraft, trucks, pipe organs, furniture, food
products, chemicals, dyed textiles, electrical equipment, tools and toys.

Thus, the Hagerstown Water Pollution Control Plant, which serves not only
the city proper but also contiguous areas, receives in addition to
domestic sewage a diversity of industrial waste and process waters.
Some of these waters exert high immediate and ultimate oxygen demands
that could not be satisfied by the existing treatment plant or were
otherwise detrimental to the biological treatment processes of the plant.
Consequently, the Hagerstown treatment plant experienced great difficulty
in achieving wastewater treatment to the degree necessary to meet the
requirements established by the Maryland Department of Health and the
Maryland Department of Water Resources.  Although the plant uses the
contact stabilization form of the activated sludge process—which in
theory ought to be able to reduce the pollutional strength of the raw
wastewaters in terms of BOD by at least 85%--it typically achieved BODg
removals in the range of only 40 to 60 percent.

From time to time, over a period of many years, treatment plant personnel
and various consulting engineering firms called in by the city conducted
at best cursory investigations to ascertain the specific causes of the
Hagerstown wastewater treatment problems.  Their findings strongly
suggested that the industrial wastewaters that were the most harmful to
the treatment plant were those from the metal plating plants and textile
dyeing plants.  Moreover, most, if not all, of these investigators strongly
suspected that certain substances in these particular industrial waste-
waters exhibited inhibitory and even toxic effects on the biota of the
treatment plant.  It was reported by one team of investigators who carried
out a fairly extensive survey of the industries "in the city that the
following noxious and toxic substances were being discharged into the
city's sanitary sewage system and reaching the treatment plant in
sufficient concentrations to be especially troublesome:

1.  Napthols—water insoluble azo dyes, which act as strong dis-
    infectants.

2.  Sodium hydrogen sulfite—a strong reducing agent, which can
    readily react with dissolved oxygen and therefore exert an
    immediate oxygen demand.  It is used in textile dyeing as
    an antichlor, primarily.


                                    1

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3.  Sodium hydrosulfite (sodium dithionite)--a reducing agent that
    is stronger than sodium hydrogen sulfite.   It is used in textile
    dyeing as a dye stripping agent and bleach.

4.  Sulfonated organic compounds—dyes and detergents.

5.  Sulfoxylates—-strong reducing agents, which  like sodium
    hydrosulfite are used as stripping agents  in textile
    dyeing.

6.  Reduced chemical dyes—complex organic compounds that,
    reportedly, are readily oxidized and require considerable
    amounts of oxygen for treatment.

7.  Chromate metallic dyes.

8.  Petroleum solvents.

9.  Miscellaneous chemicals—sulfuric acid, hydrochloric, acetic
    acid and formaldehyde.

Daily tests taken by the laboratory personnel  of the treatment plant had
indeed shown that "free sulfites", which ideally should not be present
at all in the raw wastewaters, entered the plant on week days in con-
centrations that generally ranged from 4 to 200  mg/1 and occasionally
reached as high as 450 mg/1.  Sulfites were usually not found in the
wastewater on either Saturdays or Sundays; and,  it was  noted that the
variations of sulfite concentrations during week days followed no regular
pattern.

Although the plant consistently failed to produce an effluent of accept-
able quality, the most noticeable plant operational problem—which
subjected the city government, the city engineer and plant management
personnel to much public criticism—was the continual production by the
plant of offensive odors, in particular, the pungent, "rotten-egg" odor
of hydrogen sulfide gas.  Frequently, the concentration of hydrosulfuric
acid, H2S, in the plant effluent would be found  to be as high as 10 mg/1,
and hydrogen sulfide gas would emanate from the  primary tanks and would
be swept from the aeration tanks in amounts sufficient  to annoy the
entire population of the City of Hagerstown, as  well as people of
surrounding communities.

As a result of a great public outcry, efforts  were made by plant per-
sonnel to minimize the generation of this odoriferous gas'in the aeration
basins by maintaining mixed liquor suspended solids concentrations in the
contact aeration tanks at very low levels (500 to 900 mg MLSS/1) and to
check production of the gas by constant chlorination of the return sludges
and the mixed liquors themselves.  Unfortunately, however, these efforts
were only partially successful in abating odors  and, of course, did not
improve the wastewater treatment efficiency of the treatment plant.

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In another effort to minimize treatment plant problems, key officials of
the textile dyeing plants that discharged into the city's sewage system
were contacted by representatives of the city and meetings between the
city representatives and the dye plant officials were held to inform the
dye plants officials of the difficulties being experienced by the treat-
ment plant and to solicit their aid in abating the discharge of noxious
and toxic dyeing wastes into the city's sewers.  Consequently, the dye
plants agreed to cooperate and to take certain corrective steps.
Unfortunately, however, no significant improvement in conditions at the
treatment plant was ever noted as a result of these meetings.

Also at these meetings, it was suggested that the dyeing plants should
treat their wastes before the wastes are discharged into the sewerage
system; but, it was quickly pointed out by the dye plant officials that
most of the dyeing plants are located well within the city and, have
limited, if any, space for expansion and that the possibility of them
constructing waste pretreatment systems therefore was rather small.

Consequently, in May 1967, the city formulated a research program to
study through a full-scale project various methods of actually pretreat-
ing the city's combined industrial-domestic wastewaters at the site of
the municipal treatment plant itself and, subsequently, applied to the
Federal government for financial assistance.  In March 1968, the city
received from the Federal Water Pollution Control Administration a
Federal Research and Development Grant, WPRD 149-01-68, of $320,890 or
75% of eligible project costs, whichever was less.  This grant was then
supplemented by a state grant covering 12.5% of project costs eligible
for coverage under the Federal grant.  The project costs eligible for
Federal participation equalled the total project cost of $427,853.

B.  General Study Plan

The object of the project was to study and evaluate certain pretreatment
methods aimed at rendering the city's combined industrial-domestic waste-
waters more amenable to the existing conventional biological treatment
processes of the city's wastewater treatment plant.  Since the combined
wastewaters regularly exerted high immediate and ultimate oxygen demands,
five of the six pretreatment methods that were studied were methods in-
tended to assist the existing treatment plant in meeting these oxygen
demands by providing initial oxidation.  The five pretreatment methods
were diffuse aeration with and without the addition of waste activated
sludge, chlorination, sodium nitrate addition, and potassium permanganate
addition.  Ammoniation was the sixth pretreatment scheme that was studied.
It was hoped that ammonia would prove to be effective in destroying some
of the more noxious industrial materials contained in the wastewaters.

As planned, these pretreatment methods were studied in pairs to conserve
project time and were applied to the raw wastewaters as these wastewaters
flowed through a pretreatment facility built especially for the research
project on the grounds of the Hagerstown Water Pollution Control Plant.
This facility, which was designed to handle the city's entire wastewater

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flow, was constructed between the grit chamber and the primary settling
tanks of the municipal treatment plant.  The facility consists of two^
aeration tanks, a mechanical  building for housing the necessary facility
equipment and the facility equipment.

At the design flow for the treatment plant, the facility aeration tanks
each hold 300000 gallons (40000 ft3) of wastewater and together, a total of
600000 gallons (80000 ft3) of wastewater.  Air can be supplied to the two
tanks by either or both of two positive displacement type blowers, each
having a capacity of 3500 cfm.  These blowers are a part of the facility
equipment and were purchased with project funds.  The aeration tanks with
their air supplies were intended not only for aerating the wastewaters as
called for in the project plan but also for mixing the wastewaters with
the selected chemical additives that were tested under the various study
tasks of the project.

Facility equipment also include a dry chemical feeder for feeding sodium
nitrate and potassium permanganate and a gas feeder for feeding ammonia
and chlorine.  By means of a valve-and-piping system, these feed machines
were able to deliver aqueous solutions of the various chemical additives
used in the project to the influent ends of one or the other or to both
of the two aeration tanks of the facility.

Also among the equipment of the facility are an electronic wastewater
quality monitoring system that was able to measure and record continually
the pH, dissolved oxygen concentrations and oxidation-reduction potentials
of the raw wastewaters and of the effluents of the two aeration tanks and
three automated and refrigerated samplers that collected proportionally
to the flow composite samples of the raw wastewaters and the two aeration
tank effluents.

The pretreatment facility was constructed with two aeration tanks so that,
as mentioned, two pretreatment methods could be studied at the same time.
As the wastewater flow passed through the influent channel of the research
facility, it was divided into two separate flows for separate treatment.
Beyond the project facility, the treatment plant itself was modified as
called for under the research program, to enable this flow separation to
be maintained.  Thus, the existing treatment plant beyond the facility
functioned essentially as two independent and distinct secondary treatment
systems, whose responses to the pretreatment methods being employed could
be examined.  However, it should be noted that since two studies were
always conducted simultaneously with the plant divided, one plant division
never functioned as the experimental "control" for the other.

The original project program plan provided 4 months for the design of the
project facility, a month and a half for bidding and letting of the con-
struction contract and nine and one half months for facility construction.
In addition, nine months after the project was initiated and concurrent
with project facility construction, the program plan scheduled five months
for the acquisition of necessary laboratory equipment, training of

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laboratory personnel and establishment of analytical procedures.  For a
three-month period starting twelve months after project initiation, the
plan called for extensive analyses of the wastewaters entering, passing
through and leaving the Hagerstown plant in order to gather good informa-
tion on wastewater characteristics and treatment plant performances.
Once the construction of the project facility was completed and the
baseline analyses were finished, the project plan called for the treatment
facility to be brought into service and tested and its aeration tanks
allowed to stabilize for one month.  Then, the various pretreatment
methods were to be studied in pairs, each pair being tried over a two-
month period with two weeks allotted after each study (except the last,
of course) for the incoming raw sewage to pass through the pretreatment
tanks with only plain aeration to flush out the tanks for the next study
and to allow time for process "change over."

After the various pretreatment methods were tried and evaluated, that
method that yielded the best results then was to be studied further, for
an additional two months; but, this time, the study was to be done with
pretreatment method being applied to the entire wastewater flow and with
the secondary systems of the treatment plant recombined so that the plant
beyond the pretreatment facility would function as a single unit as it
had before the pretreatment studies were begun.

Also included in the project program plan was a survey of certain select
industries within the city—industries that were suspected of being possible
sources of the more noxious and toxic wastes that the treatment plant was
receiving.  On the basis of the assumption that most of the noxious and
toxic wastes were contributed by the textile dyeing plants, these plants,
in particular, were considered of primary interest and, therefore, were
the main concern of the planned survey.  This survey was scheduled to
begin one month after the start of the project and to end seven months
later.

Except for delays in construction of the project facility and in the con-
struction of an additional final settling tank for the treatment plant
and modification of two existing final settling tanks (work not done under
the program of the research project) and extensions of a pretreatment
study and the industrial survey periods, this project schedule and plan
was essentially adhered to.  The project program tasks and the actual
periods over which they were carried out are as follows:

     Period                                    Project Task

5/22/68 - 10/1/68                   Site studies and design of project
                                    facility.

10/1/68 - 12/11/68                  Review of facility plans and
                                    specification by state and
                                    federal agencies.

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      Period
                                     Project Task
12/23/68 - 1/30/69




8/1/68 - 9/31/70

10/1/68 - 7/15/69
7/15/69 - 5/19/70
1/27/70 - 5/19/70
5/19/70 - 7/24/70
7/24/70 -


8/18/70 -



10/15/70


10/31/70
 8/18/70


 10/15/70



- 10/31/70


- 12/25/70
12/25/70 - 1/18/71
1/18/71 - 3/23/71
Construction of project facility
and modification of treatment plant
piping to achieve two separate
secondary treatment systems.

Survey of industrial plants.

Preparation of treatment plant
laboratory for analytical program
of the project, training of
laboratory personnel, and establish-
ment of analytical procedures.

Execution of baseline studies--
analysis of treatment plant waste-
waters.

Startup of project facility,
stabilization of the aeration
tanks of the facility, and
installation and calibration
of the facility wastewater
quality monitoring system.

Investigation of wastewater pre-
treatment by plain aeration and by
aeration with addition of waste
activated sludge.

Preparation for the next pair of
pretreatment studies.

Investigation of wastewater pretreat-
ment by addition of ammonia and by
addition of sodium nitrate.

Preparation for next pair of pre-
treatment studies.

Investigation of wastewater pretreat-
ment by addition of chlorine and by
the addition of potassium permanganate.

Preparation for final pretreatment
studies—recombination of in-plant
wastewater flows.

Application of pretreatment by
chlorination, to entire raw waste-
water flow.

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     Period                                   Project Task

2/20/71 - 1/16/71                   Loading of specially prepared digestor
                                    with combined sludges and digestion of
                                    sludges for sludge dewatering studies.

4/1/71 - 4/7/71                     Studies on dewatering of digested
                                    sludges and waste activated sludge
                                    on a pilot vacuum filter.

4/15/71 - 4/21/71                   Studies on dewatering of digested
                                    sludges on an existing sand bed.

4/21/71                             Supplementary analyses and data
                                    tabulation.

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                                SECTION I I

                               CONCLUSIONS
From May 22, 1968, to April 21, 1971, the City of Hagerstown, Maryland,
investigated six proposed schemes of pretreating its combined domestic-
industrial wastewaters.  These schemes or methods, which, during the
investigation, were applied to the city's raw wastewaters at the site of
the city's wastewater treatment plant, were pretreatment by plain aera-
tion, aeration with the addition of waste activated sludge, ammoniation,
chlorination, addition of potassium permanganate, and addition of sodium
nitrate.  It was hoped that one or more of these methods would be effec-
tive in significantly increasing the rather poor degree of treatment the
existing plant was able to achieve and in eliminating the frequent
evolution from the plant of the malodorous gas hydrogen sulfide.

During the project, it was found that the plant suffered from (1) hydraulic
overloading during wet-weather conditions as a result of the considerable
susceptibility of the city's sanitary sewage system to stormwater inflow,
(2) organic overloading occurring regularly on week-day mornings as a
result of batch discharges of cottage cheese whey from a local  food pro-
cessing plant and (3) the frequent presence in the raw wastewaters of
dye stripping agents (which exerted high immediate oxygen demands) and
intensely colored dye stuffs from local textile dyeing plants.

The hydraulic and organic overloads were overwhelming in their impacts
on the treatment plant and were obviously the major causes of the treat-
ment difficulties the facility was having.  In addition, it is believed
that, because of their overwhelming nature, the two types of overloads
could have easily obscured other factors contributing to the poor treat-
ment performance of the plant.  Moreover, they interfered greatly with
several of the pretreatment studies of the project, particularly the
hydraulic overloads as they varied widely in their magnitudes and in
the times and extents of their occurrences.

Even so, it was definitely determined that there were not present in the
municipal wastewaters, at least in effective concentrations, any materials
that were toxic or inhibitory to the treatment plant biota,  Thus,
contrary to the opinions expressed by certain previous investigators, the
biological processes of the plant were not being affected by bacterio-
cidal or bacteriostatic substances in the wastewaters.

During the base-line studies of the investigation, it was discovered, too,
that among the biota of the treatment plant there was an appreciable
population of a filamentous sulfur organism, which, it is concluded,
markedly affected the settleability of the mixed liquor suspended solids
and contributed appreciably to the high-solids carry-over into the final
plant effluent that the plant had been experiencing for some time.  This

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bacterial population, however, was subsequently eliminated from the
plant, in the pretreatment studies, through the preaeration of the raw
wastewaters.

Other conclusions that were drawn from the results of the investigation,
in particular the pretreatment studies themselves, are as follows:

1.  Pretreatment of the municipal wastewaters by plain aeration,
    by aeration with the addition of activated sludge, and by
    chlorination were effective in improving the degree of waste-
    water treatment achieved by the treatment plant.

2.  Preaeration of the municipal wastewaters effectively reduced
    the evolution of hydrogen sulfide gas from the treatment plant
    and produced a better settling biological floe in the secondary
    system by essentially eliminating from the aeration tank bio-
    masses the above mentioned population of the filamentous sulfur
    bacterium.

3.  Pretreatment of the municipal wastewaters by addition of sodium
    nitrate lead to the floatation (assumably through denitrification)
    of raw primary and waste activated sludges deposited in the
    primary settling tanks of the treatment plant and, in addition,
    may have stimulated the growth of a hitherto unidentified
    filamentous organism that appeared in such great abundance
    during the application of this method that the settleability
    of the solids in the aeration tanks and in the anaerobic
    digesters of the plant were considerably impaired.

4.  Pretreatment by addition of ammonia may have improved plant
    performance somewhat; but, the experimental data are incon-
    clusive as a consequence of the fact that the plant, during
    much of the time period devoted to the study of this method,
    was upset by severe hydraulic overloading.

5.  No noticeable benefits were obtained by pretreatment with
    potassium permanganate; however, it is felt that the dosages
    applied were minimal and that higher dosages should have been
    tried.

6.  Pretreatment by chlorination increased color removal but only
    at the higher chlorine dosages used in the pretreatment study.
    The other pretreatment methods were not noticeably effective.

In addition, it is also concluded that, by the combination of substantial
reduction of stormwater inflow into the city's sewerage system, applica-
tion of pretreatment by plain aeration with the addition of waste activated
sludge and flow equalization over 24 hours of the slug discharges of the
cheese whey from the food processing plant, the Hagerstown Water Pollution
Control Plant should be able to achieve BOD5 removals of 90% or better.

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                               SECTION III

                             RECOMMENDATIONS
Based on the experimental  data and conclusions of this project, the
following recommendations  are offered:

1.  The inflow of stormwater into the city's  sanitary sewerage
    system should be substantially reduced.

2.  The batch discharge into the sanitary sewerage system of
    significant amounts of high pollutional strength wastes,
    noxious materials, and/or bacteriocidal or bacteriostatic
    substances should be prohibited;  and, the installation of
    aerated waste flow equalization tanks by  industries currently
    practicing batch discharging of appreciable volumes of waste-
    waters should be strongly encouraged.

3.  Pretreatment of the municipal wastewaters by plain Deration,
    or by the combination  of aeration and the addition of waste
    activated sludge, or by chlorination should be practiced.

4.  Pretreatment of the municipal wastewaters by addition of
    sodium nitrate should  definitely not be employed because
    of its adverse effects on the municipal treatment plant.

5.  The use of other oxidants, such as  ozone, pure oxygen and
    hydrogen peroxide, for pretreatment should be explored; and,
    the method of pretreatment with potassium permanganate should
    be tried with higher permanganate dosages.
                               10

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                                SECTION IV

       THE PROJECT SITE—THE HAGERSTOWN WATER POLLUTION CONTROL PLANT--
                        AND THE PROJECT FACILITY
A.  Description of the Hagerstown Water Pollution Control  Plant

The Hagerstown Water Pollution Control Plant is located on a 300-acre
farm in the southeastern part of the City of Hagerstown and receives  the
wastewaters not only from the city but areas surrounding the city.
It serves a population estimated to be about 43500 people.  The plant is
of the conventional activated sludge type with a design average hydraulic
load capacity of 7.5 mgd.  However, in an effort to effect better treat-
ment, it now employs the contact stabilization modification of the
conventional activated sludge process.  Its treated effluent discharges
into Antietam Creek, a major tributary of the Potomac River.

The original municipal treatment plant was constructed in 1924.  Over the
years, as the city grew, the plant was improved and expanded.  Today, the
plant (exclusive of the project facility) and the city's sewerage system
consist of the following units:

1.  Outfall Sewer

    A 54-inch reinforced concrete box sewer serving a separate sanitary
    sewerage system laid throughout the confines of the city limits and
    contiguous areas in Washington County.  The capacity of the 54-inch
    outfall is approximately 25.0 mgd.

2.  Grit Removal Facilities

    The existing grit removal facilities of the plant consist of two
    grit chambers; one is a gravity type and the other, an aerated
    type.

    The gravity type grit chamber is  18'-0" x 18'-0" x T-6" normal
    water depth with 2'-0" maximum water depth and is equipped with
    a circular grit collector and other mechanical means for removing
    grit from the  unit.  The volume at T-6" depth is 488 ft3  (3640 gal)
    to give a detention time of 0.88 minutes at 6.0 mgd; the volume at
    2'-0" depth is 648 ft3  (4850 gal) to give a detention time of 0.58
    minutes at 12.0 mgd flow.  Because this grit chamber does  not give
    satisfactory operating  results, it is presently not used except as
    a stand-by unit.

    The aerated grit chamber, which has mechanical conveyor equipment to
    remove the grit from the tank for disposal into a truck, is 18'-0"
    long x 16'-0" wide x 12'-8" water depth at a flow rate of  12.0 mgd.
    The detention  time that this chamber provides at 12.0 mgd  flow is
    3.25 minutes.

                                   11

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3.  Screen and Comminutor

    A manually cleaned coarse bar screen with 3-inch clear openings is
    installed in the 54-inch outfall  sewer ahead of the grit chambers
    to catch and remove the heavy trash.

    On the downstream side of the grit chamber, there is a Chicago Pump
    Model 25A comminutor to cut up all coarse material  in the sewage.
    This machine has a capacity to handle wastewater flows from 1.5 to
    25.0 mgd.

4.  Primary Settling Tanks

    The plant has two rectangular primary settling tanks, each being
    75'-0" x 16'-0" with a 10'-0" water depth, which have a combined
    volume of 179500 gallons and one  circular primary settling tank,
    which is 55'-0" in diameter with  a lO'-O" side water depth and a
    2'-3-1/2" deep hopper bottom and  has a volume of 178000 gallons.
    The plant, therefore, has a total  primary settling  volume of
    357500 gallons.  Each rectangular tank has a surface area of 1200
    ft^ and the circular tank a surface area of 2380 ft^ for a total
    settling area of 4780 ft*.  Furthermore, each rectangular tank
    has a weir length of 16 ft and the circular tank has a weir length
    of 173 ft to give a total weir length of 205 ft.

5.  Aeration Tanks

    There are in the plant six spiral-flow aeration tanks in two
    batteries of three tanks each.  Each tank is 122'-Q" x 16'-0" x
    15'-0" water depth, providing a volume of 29280 ft3/tank, 87800
    ft3/battery or a total of 175680  ft3 for the six tanks.  In addition,
    the plant has a battery of two spiral-flow aeration tanks, each being
    95'-0" x 30'-0" x 15'-0" water depth with a 42750 ft3 volume.  The
    total volume provided by eight aeration tanks is therefore 261180 ft3.

    Of the six tanks constructed in two batteries of three tanks, each
    tank has a double row of air diffuser tubes along one side and four
    transverse wood baffles that divide the tank into five equal volume
    sections and extend from above water surface to within one foot of
    tank bottom to reduce short circuiting.  Each aeration tank of the
    two tank battery has air diffusion tubes mounted 2'-0" above the
    tank bottom in two rows on 4-inch air headers suspended from six
    "swing-diffuser" assemblies.

    Although originally designed for  the conventional activated sludge
    process, the two batteries of three aeration tanks  per battery and
    the battery of two aeration tanks are operated in the contact
    stabilization mode.  The aeration tanks of each three-tank battery
    are employed in series with return activated sludge being discharged
    into the head end of the first of the three tanks in the series and
                                   12

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    primary effluent being introduced into the head end of the third or
    last tank in the series.  Thus, in each, three tank battery, the first
    two tanks function as sludge reaeration tanks while the third tank
    functions as a contact aeration basin.  In the one battery of the
    two aeration tanks, one of the two tanks serves as the sludge
    aeration tank, and the other, as the contact aeration tank.

    The return sludge to both of the three tank batteries is a combina-
    tion of the settled activated sludges from the three settling tanks
    that follow the two batteries.  The return sludge to the two tank
    battery is taken from the one settling tank that follows this
    battery.

6.  Final Settling Tanks

    The flow from the battery of six aeration tanks is conveyed to two
    square settling tanks and one circular settling tank which was
    built during the construction of the project facility and brought
    into use just before the beginning of the first pair of pretreatment
    sludges.  Each square settling tank is 50'-0" x 50'-0" x lO'-O" side
    water depth with 3'-0" hopper depth and is equipped with a circular
    type collector system.  Each tank has a center feed well and two
    weir troughs extending across the tank and one weir plate along a
    side.  And, each tank has a surface area of 2500 ft2, a volume of
    195000 gallons and a weir length of 247 ft.  The single circular
    settling tank is 55'-0" in diameter x 10'-0" side water depth and
    is equipped with a suction type sludge collector.  The tank has a
    surface area of 2380 ft2, a volume of  178,000 gallons, and a weir
    length of 173 ft.

    The flow from the battery of two aeration tanks is conveyed to one
    circular final clarifier tank which is 60'-0" in diameter with a
    11'-0" side water depth and a 2'-4-3/8" deep hopper bottom.  The
    tank is equipped with a circular sludge collector, which moves
    sludge to sump located in center of tank.  The tank has a volume
    of 31100 ft3, a surface area of 2827 ft2 and a weir overflow length
    of 188 ft.

    Together, all the final settling tanks of-the treatment plant have a
    total surface area of 10200 ft2, a total volume of 822,000 gallons
    and a total weir length of 855 ft.

7.  Chlorine Contact Tanks

    There are two chlorine contact tanks, each being 61'-0" x 44'-0"
    x 5'-0" water depth and having five dividing walls or baffles to
    form end around flows in the 44-foot direction.  Each tank has a
    volume of 100650 gallons to give a total volume for chlorination
    of 201300 gallons.  These tanks are rather recent additions to the
    treatment plant system.  They were, in fact, constructed during the
                                   13

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     baseline study period of the research  project and were not brought
     into service until  well  after the pretreatment studies of the project
     were initiated.

 8.   Sludge Thickening

     Sludge from the primary  tanks,  which  is  a  mixture of waste activated
     and raw sludges, is thickened before  going to the digesters in a
     tank which is 20'-0" in  diameter x lO'-O"  deep and equipped with a
     Dorr picket-fence type mechanical  thickener.   The volume of the tank
     is 3140 ft3.

 9.   Sludge Digestion Tanks

     Sludge from the thickening tank is pumped  to  one of five digesters.
     Four of the digesters are heated by hot  water circulated through
     coils installed in the digesters and  are mixed by gas recirculation.
     The remaining digester is not heated  or  covered.   It is used as a
     sludge storage tank and  is provided with a small  aeration system
     for mixing and scum breaking.

     The capacities of these  tanks are as  follows:

     Digester No. 1 (Primary)   - 53015 ft3
     Digester No. 2 (Secondary) - 49088 ft3
     Digester No. 3 (Storage)   - 53015 ft3
     Digester No. 4 (Primary)   - 53015 ft3
     Digester No. 5 (Secondary) - 49088 ft3

     The total capacity of all the digesters, excluding Digester No. 3,
     is ft3; the total capacity of all  the digesters,  including Digester
     No. 3, is 257221 ft3.

     Digesters No. 1  and No.  4 are 50'-0"  diameter x 24'-6" side water
     depth x 5'-9" hopper depth and are provided with fixed steel covers.
     Digesters No. 3 and No.  5 are 50'-0"  diameter x 22'-6" side water
     depth x 5'-9" hopper depth and are provided with gas storage type
     floating steel covers.  Digester No.  3 is  of  same size as Digesters
     No. 1 and No. 4.  As mentioned, it is  open and serves as a sludge
     storage tank as well as  a digester. Sludges are normally pumped to
     Digester No. 1 with overflow to Digester No.  2 and from there to
     Digester No. 3, or into  Digester No.  4 with overflow into Digester
     No. 5 and from there to  Digester No.  3.

10.   Sludge Drying Beds

     Although most of the digested sludges  are  carted away by tank trucks
     for disposal on farm lands, the treatment  plant has four open sludge
     drying beds, each 90 ft  x 26 ft, and  six beds, each 121 ft x 47 ft,
     enclosed by a structure  having a steel roof and open sides.  The
     total drying bed area is 43482 ft?.


                                   14

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11.  Return Sludge Pumps

     The sludges from the two 50-foot square and the one 55-foot
     diameter circular clarifiers are pumped by either one or both
     of two 1900 centrifugal pumps to the battery of six aeration
     tanks, through two 8" discharge lines.

     The sludge from the 60-foot diameter circular clarifier is
     pumped by either one or both of two 950 cfm centrifugal pumps
     to one aeration tank of the battery of two aeration tanks.

     All pumps are provided with constant speed motors and the rates
     at which sludges are returned are controlled by throttling gate
     valves in the discharge lines of the pumps.  Total return sludge
     capacity of the plant is 5700 gpm or 6.1 mgd with all pumps
     operating.

12.  Blowers
     Air requirements are furnished by the following equipment:

     (1)  One Roots-Connersville two speed positive displacement
          type blower with maximum capacity of 2562 cfm (1900 cfm
          at 695 rpm, 2562 cfm at 870 rpm);

     (2)  Two Ingersoll-Rand Centrifugal blowers, each rated at
          1500 cfm to 3000 cfm; and,

     (3)  One Chicago Standardaire two speed positive displacement
          blower with maximum capacity of 1600 cfm (900 cfm at
          1150 rpm, 1600 cfm at 1750 rpm).

     The air lines are interconnected so that air from all blowers can
     supply all aeration tanks.

B.   Capacities of Existing Sewage Treatment Units

1.   Grit Chambers

     Each grit chamber is designed for a capacity of 12.0 mgd; thus,
     both units together have a maximum capacity of 24.0 mgd.

2.   Comminutor

     The comminutor is rated for a maximum capacity of 25.0 mgd.
                                  15

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3.   Primary Settling Tanks

     At 10.0 mgd flow, these tanks  provide a  detention  time  of 51.5
     minutes, a surface settling rate of 2100 gals/ft2/day and a  weir
     overflow rate of 48800 gals/ft/day.

4.   Aeration Tanks

     With a total volume of 1950000 gallons and based on mixed liquor
     suspended solids concentration in the aeration tanks of 3500 mg/1
     and loading of 35 Ibs 6005 per 100 Ibs solids, the organic load
     capacity of aeration tanks is:

          Ibs BOD5
          - - - - = 1.95 mgd x 3500 mg/1  x 8.34 =  19850 Ibs/day
             Uajr

          Assuming Average BOD5 of 225/mg/l ,  the waste  flow  yielding
          the above loading would be
          Flow =       = 10.6 mgd
               8.34 x 225
                                                         »
     The detention time in the aeration tanks at 10.0 mgd flow would
     be 4.68 hours.  (The detention time at design  flow,  7.5 mgd,  is
     6.2 hours.)

5.   Final Settling Tanks

     Based on surface settling rate of 1000 gals/ft^/day, the settling
     tanks can handle 10.2 mgd per day, providing a detention time of
     1.93 hours and a weir overflow rate of 11930 gals/ft/day.

6.   Chlorine Contact Tanks

     The volume of 201300 gallons at 30-minute detention  time provides
     sufficient capacity to handle an average flow of 9.67 mgd.

7.   Sludge Digestion

     Since high rate digestion by gas recirculation is rated at 2.0
     ft3 per capita, the four anaerobic digesters with a  total volume
     of 204206 ft3 can handle a total equivalent population of 102103
     persons.  Therefore, even without the digester/storage tank,  the
     digester capacity of the treatment plant is more than adequate.

8.   Sludge Drying Beds

     Sludge drying beds rated at 1.5 ft3 per capita and having an  area
     of 43482 ft2 can handle an equivalent population of 29000 persons
                                 16

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     and with tank truck disposal as the major method of disposing the
     sludge, sludge bed capacity is adequate to serve during weather
     periods when tank truck disposal is not possible.

C.   Project Modifications of the Hagerstown Hater Pollution Control
     PTant                  "~	

In order to be able to carry out two pretreatment studies at the same
time in accordance with the project program plan, it was necessary to
have the effluents from the two aeration tanks of the pretreatment
facility fed separately to two independent treatment systems--each
system having its own primary and secondary units and distinct sludge
return systems.  Because of the layout of the Hagerstown plant, the
dividing of the plant into two separate treatment systems required only
minor changes in the piping arrangement of the plant.

Specifically, the following changes were made in the treatment plant
piping system:

The concrete wastewater distribution box that precedes the primary
settling tanks of the treatment plant was hydraulically connected to the
longitudinally divided effluent channel of the pretreatment facility and
sectioned by means of a simple, transite divider wall into two compart-
ments.  The sectioning was done in a manner such that in the box the
effluent from one pretreatment tank (referred as pretreatment Tank A)
would flow to and be distributed between the two rectangular primary
settling tanks and the effluent from the other pretreatment tank
(pretreatment Tank B) would flow into the circular primary settling tank
of the treatment plant.

The piping for the circular primary tank effluent was changed to enable
this effluent to be conveyed directly to the contact aeration tank of the
two-aeration-tank battery; and the piping for the rectangular primary tank
effluents was modified so that these effluents would flow to only the
contact aeration tanks of the two three-aeration-tank batteries.  Originally,
the effluent of the circular primary tank was combined with the effluents
from the rectangular settling tanks; and, then, the combined primary
effluent flow was distributed among the three contact stabilization tanks
of the treatment plant.

No further piping changes were necessary in the existing plant since the
wastewater flow entering the two three-tank batteries and the flow enter-
ing the one two-tank battery are not combined until the treated wastewaters
are finally discharged to the receiving stream and since the return sludge
systems of the two groups of aeration tanks were already separate systems.

As a result of these few piping changes, the plant was able to function
as two distinct and independent treatment systems.  The two distinct
                                     17

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treatment systems thus formed are referred to herein as Systems A and B
and were comprised of these treatment plant units:

    Treatment System A                   Treatment  System B

1.  Pretreatment Tank A.             1.  Pretreatment Tank B.

2.  The two rectangular primary      2.  The circular primary settling
    settling tanks.                      tank.

3.  The two three-aeration-tank      3.  The battery of two aeration
    batteries.                           tanks.

4.  The two square and the 55-foot   4.  The 60-foot diameter circular
    diameter circular final              final settling tank.
    settling tank.

D.   Project Facility

1.   Design of the Project Facility

     Immediately after the initiation of the research project, certain
     preliminary engineering studies of the project site were made to
     secure those site data needed to design and to integrate struc-
     turally and hydraulically the project facility into the existing
     Hagerstown treatment plant.  A survey crew gathered data on
     pertinent ground elevations and invert elevations of existing pipe
     lines, channels, and junction and distribution boxes.  These data
     then were used to prepare a preliminary site plan showing the
     critical invert elevations and site topography.  On the basis of
     the survey data and prepared site plan, engineering determinations
     were made as to the best location for the two  pretreatment tanks
     and the facility influent and effluent conduits; and, subsequently,
     preliminary plans of the project facility were developed.

     The plans that were generated called for the aeration tanks of the
     facility to be located between the existing comminutor chamber and
     the concrete division box that distributes the wastewater to the
     primary settling tanks of the plant.  It was known, however, that
     the hydraulic head differential between the chamber and the box was
     rather small; but, it was not known for certain how small.  Conse-
     quently, to ensure that accurage design data were available, field
     measurements of water levels were made at key  points in the treatment
     plant system during low and high sewage flows  and during wet weather
     conditions.  These field measurements extended from a low flow of
     2.3 MGD to a high flow of 30.4 MGD.  The resulting data confirmed
     the tightness of hydraulic conditions for the  proposed facility,
     they showed that it was feasible to locate the facility as proposed
     in the preliminary plan.  Subsequently, the final engineering plans
     for the facility were generated and approved.
                                    18

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                                                                                    EFFLUENT
                              AERATION TANKS (B)
                                                FINAL TANK
                                                                  CHLORINE CONTACT TANK
Figure 1.   Schematic Diagram of  the Hagerstown Water Pollution Control  Plant

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    The fundamental  considerations  that were  made  in  the  planning  of  the
    project facility were  that:   (1)  the  facility  must  fully meet  the
    needs  of the  project program  for  such a structure,  (2)  the  facility
    ought  to be useable  for post  project  pretreatment operations involv-
    ing the entire plant including  any likely plant expansions,  (3) the
    wastewater flow into and out  of the facility should be  by gravity
    to obviate the need  for pumping,  (4)  the  loss  of  head through  the
    facility must be minimal, (5) the Hagerstown treatment  plant must
    be able to continue  to operate  while  the  facility is  being  constructed,
    and (6) the cost of  the facility  should be as  low as  reasonably
    possible.

2.   Description of the Project Facility

    The project pretreatment facility, which  consists of  two aeration
    tanks  (i.e.,  pretreatment tanks)  of compressed-diffused air design
    with their influent  and effluent  channels and  a building for housing
    the facility  equipment—blowers,  electrical controls, wastewater
    monitoring and sampling units,  chemical feed machines,  etc.—was
    constructed as planned ahead  of the primary settling  tanks  and
    downstream from the  comminutor  basin  of the Hagerstown  Water
    Pollution Control Plant.

    A concrete manhole located 80 feet downstream  from  the  comminutor
    basin  was enlarged under the  facility construction  task of  the project
    to receive a  42-inch concrete pipeline that also  was  built  under  the
    project to intercept the raw  wastewater flow of the plant at the
    manhole and carry it some 100 feet to the aeration  tanks of the
    pretreatment  facility.  Two stop  gates were installed in the enlarged
    manhole in order that  the raw sewage  could be  allowed to flow  through
    either the 42-inch concrete influent  line of the  pretreatment  facility
    or the original  42-inch line  of the treatment  plant in  order to by-
    pass the facility.  The 42-inch influent  line  of  the  facility  discharges
    into the head end of a grating-covered V-shaped channel formed in and
    running the full length of the  coping wall  that separates the  two
    facility pretreatment  tanks.  An  air  diffusion system is installed
    in the coping wall channel itself to  prevent deposition of wastewater
    solids in the channel.  Toward  the end of the  coping  wall channel,
    the channel is divided so as  to split the .wastewater  flow into two
    separate streams. At  the very  end of the channel,  these two flow
    streams are then directed downward through separate openings in the
    bottom of the divided  channel and into vertical down  channels  that
    are formed in the corners of  the  pretreatment  tanks.  These vertical
    down channels extend below the  line of air diffuser elements in the
    pretreatment  tanks so  that each of the two separate wastewater flow
    streams is introduced  into its  respective pretreatment  tank at a
    point  where rapid and  vigorous  mixing can occur.
                                    20

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Each pretreatment tank is 30'-0" wide x 95'-0" long with a 15'-0"
maximum water depth for a total water capacity for both tanks of
6.30 x 105 gallons (8.40 x  10^ ft3).  At the average design flow
for the treatment plant (7.5 MGD) the water depth in the tanks is
14'-3" and total capacity of the tanks is 6.00 x 105 gallons
(8.00 x 104 ft-3) for  a detention time of 2.0 hours.  The tanks as
aeration basins are of the  spiral flow design with swing type air
diffusers (Chicago Pump "Swing Diffusers").  There are seven swing
diffuser assemblies in each tank with 12'-10" air headers each
equipped with 16 Chicago Pump  "Shearfuser" air diffuser elements
mounted on 9-inch centers and  7 evenly spaced Chicago Pump "Discfuser"
diffusers mounted on  piping that extend out from the headers to
beneath the coping wall.  The  purpose of these discfusers is to
prevent the formation during aeration of a dead volume (confined
roll) under the appreciable overhang of the coping wall.

In the end wall of each pretreatment tank—the end wall at the head
of the coping wall channel  and opposite the end wall where the waste-
water flow is introduced into  the tank—a 48-inch wide rectangular
opening is provided to connect the  tank to a 48-inch wide rectangular
channel that carries  the tank  effluent to the previously mentioned
concrete division box of the treatment plant that distributes the
wastewaters to the primary  settling tanks.  During all of the pre-
treatment studies except the last,  pretreatment by the "select
method" involving the operation of  the entire treatment plant as
a single system, this 48-inch wide  effluent channel was divided by
an asbestos-board divider wall into two channels to provide a
separate channel for  each pretreatment tank effluent.  This division
was carried up to and, as mentioned, through the concrete division
box.  In addition, because  it was anticipated that low-flow velocities
would exist in the 48-inch  wide effluent channel, an air pipe line was
installed in the channel in order that the effluent waters in either
the channel as a whole or its  divisions could be aerated to keep
particulate solids in suspension.

In order to be able to bring waste  activated sludge to the head
ends of the pretreatment tanks and  there to mix the sludge with the
incoming raw wastewater as  required by the project program plan, the
6-inch waste activated sludge  line  of the treatment plant that
terminated in the concrete  division box preceding the primary tanks
was extended to the influent end of the pretreatment tanks where
another concrete box  was built to receive the extended line and to
distribute the sludge to either or  both of the coping wall influent
channels of the pretreatment tanks. This sludge distribution to
either or both influent channels was made controllable by means of
adjustable discharge  weirs  in  the concrete sludge distribution box,
each weir leading to  one channel in the coping wall.  Pumping of
waste activated sludge to the  pretreatment tanks can be accomplished
as required by one or both  of  two activated sludge pumps of the
treatment plant.  These pumps, which as stated earlier, have a
capacity of 1900 gpm  each when pumping sludge to the concrete

                                  21

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distribution box ahead of the primary tanks, lose about 35% of their
pumping capacity when pumping sludge to the sludge distribution box
of the pretreatment tanks.  This loss stems from the increase in the
total dynamic head of the pumping system as a result of the extension
of the sludge line.  During the project, a single pump provided, as
anticipated, all the pumping capacity necessary however to satisfy
the sludge pumping requirements of the project program.

Housed in the mechanical building of the project facility are the
following facility equipment, which were purchased and installed
under the grant program:

(1)  Two Ingersoll-Rand positive displacement blowers each capable
     of delivering to the pretreatment tanks 3500 cfm of air at
     15 psig.

(2)  Two mercury manometers reading 0 to 10 psig and. mounted in
     the discharge piping of each blower to measure to the air
     pressure in the lines.

(3)  Two Permutit Company Permatubes fitted with manometers and
     installed in the two air mains of the facility leading from
     the blowers to the pretreatment tanks.  These are Venturi
     type devices for measuring the air flows to the pretreatment
     tanks.

(4)  Three Chicago Pump Tru-Test Samplers for collecting and holding
     under refrigeration composite samples of the common influent
     (raw wastewaters) and the separate effluents of the two pre-
     treatment tanks.  These samplers are capable of sampling either
     proportionally to the raw wastewater flow (being paced by the
     plant flow meter located at the head end of the treatment system)
     or at a constant rate which is set by a timer-controller provided
     with each sampler.  They are dip type samplers and each can take
     three to twenty 25-ml sample aliquots per hour and automatically
     composite them into a single sample and store the composite in a
     2-gallon bottle kept in a refrigerated compartment in the unit.

(5)  Three Megator L 100 positive displacement "Snore Pumps" for
     pumping the various wastewaters to the Tru-Test Samplers.  These
     pumps are located next to the samplers in the mechanical building
     of the pretreatment facility and are driven by one horsepower,
     1150 rpm electric motors through variable pitch pulley and belt
     drives to give a range of pumping rates.

(6)  An electronic wastewater quality monitoring system for continuous
     automatic measurement and recording of the pH's, dissolved oxygen
     concentrations and oxidation-reduction potentials of the pre-
     treatment tank influent and effluents.  This system was manufactured
     by Automated Environmental System, Inc.  During the project the
                                   22

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     sensing probe assemblies of the system were mounted in the
     submersible, stainless-steel baskets that were placed just
     outside of the mechanical building of the project facility
     in the appropriate wastewater channels.

(7)   An ammoniator-chlorinator for metering and feeding tank
     ammonia or chlorine in solution form into the pretreatment
     tanks.  This device is a Wallace and Tiernan Modular Series
     V-800 Chlorinator with a capacity for feeding 2000 Ibs of
     chlorine per day and, through slight modification, 950 Ibs
     of ammonia per day.  By means of the chemical feed-line-
     piping-and-valving arrangement of the project facility, the
     ammoniator-chlorinator can supply either ammonia or chlorine
     to either or both of the pretreatment tanks.  The feed machine,
     for obvious safety reasons, is installed in a separate, well
     ventilated room in the mechanical building.  On the open con-
     crete pad of the building are located the manifolds and storage
     areas for the ammonia 150-lb and chlorine 2000-lb cylinders for
     the gas feed machine.

(8)   Two chlorine scales, Force Flow Equipment Chlor-Scale Model
     6D80, which are installed in the concrete pad of the mechanical
     building and are sized to hold and weigh two 1-ton chlorine
     cylinders each.  The scales read from 0 to 8000 Ibs.

(9)   A dry chemical feeder for metering and feeding sodium nitrate
     and potassium permanganate to the pretreatment tanks.  This is
     a Wallace and Tiernan, Inc., Screw-Type Volumetric Feeder,
     Series A-690, having a control feed range of 20 to 1 and a
     maximum feed rate for pelletized sodium nitrate of 1170 Ibs/day
     and for "free-flowing" potassium permanganate of 312 Ibs/day.
     The feeder meters and deposits powdered chemicals into a
     35-gallon solution tank  contained in its base where the dry
     chemicals with the aid of a mechanical stirrer are dissolved
     in tap water.  From the  solution tank, the dissolved chemicals
     can be fed by gravity flow to either or both of the pretreatment
     tanks.  The machine is equipped with a 28-ft3 hopper extension
     to provide a total hopper capacity of 6.0 ft3.  The additional
     hopper capacity provided by the extension allowed enough sodium
     nitrate to be stored in  the machine that when the machine was
     used to feed sodium nitrate at the maximum rate, it refilled
     not quite once each shift.  (Bulk density of sodium nitrate is
     approximately 75 lbs/ft3)
                                  23

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•• -

          Figure 2.  A View of the Pretreatment Facility from the Head End of the Pretreatment Tanks

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r j
           Figure  3.
A View across the Pretreatment Tanks of the Project Facility,  Showing  the
Primary Settling Tanks and Other Parts of the Hagerstown Water Pollution
Control Plant in the Background

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Figure 4.   The Project Facility immediately prior to
           Wastewaters into the Pretreatment Tanks
the Introduction of the Municipal

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                               SECTION V

                           BASELINE STUDIES


A   Preliminary Wastewater Analyses

.1.  Establishment of Analytical Procedures

    Shortly after the project was begun, an  inventory of the equipment
    and chemicals in the  laboratory of the Hagerstown sewage treatment
    plant, was conducted and  those laboratory items that the laboratory
    did not have but that would be needed for the project were purchased.
    As had been proposed, the purchases were made partly with project
    funds designated for  this purpose and partly with "non-project
    funds" provided by the city.  Once analytical systems were set up,
    laboratory personnel  were trained by the professional chemists of
    the project team in carrying out those standard analytical tests
    that the laboratory personnel were not familiar with and that would
    be conducted routinely throughout the lifetime of the project.

    All standard chemical analyses performed on wastewaters during the
    project except for the determination of  the oxygen demand indicates
    (GDI's) and sulfite and  hydrogen sulfide contents of wastewaters
    were conducted in accordance with the 12th Edition of Standard
    Methods for the Examination of Water and Wastewater, 1960, APHA,
    AWWA and WPCF.The ODI  determinations were done following the
    Hach procedure patterned after the Department of Public Health of
    Illinois ODI test.  The  sulfite concentration measurements were done
    using the Hach SU-2 Sulfite Test Kit and the hydrogen sulfide con-
    centration determinations were made by means of the Hach "Screening
    Test for Soluble Sulfides."  These Hach  procedures were adopted be-
    cause of the rapidity and ease with which they could be performed
    by most of the personnel of the plant.

    While laboratory personnel were being trained and for a short time
    thereafter, all the adopted standard analytical procedures were checked
    carefully and all the analytical instrumentation was meticulously
    checked to insure that all analytical measurements would yield
    reasonably accurate results for all the  various analytical conditions
    that would be encountered in the different operational studies of the
    project.  Moreover, several techniques for using gas chromatography
    to detect and to trace through the treatment plant various volatile
    organic components of the Hagerstown wastewaters were explored.
    Among the several candidate chromatographic techniques examined,
    the techniques or, more  precisely, combination of techniques that
    were judged to be most suitable for the  project and, therefore,
    adopted for project use  were "freeze concentration" of the volatile
                                     27

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    wastewater organics  for improved detection,  injection  and  volatili-
    zation of the concentrated samples  in the gas  chromatograph,
    separation of the volatile organics on either  a  SE-30  or Porapak Q
    thermally programmed column,  and detection of  the separated components
    by means of a flame  ionization detector.   The  gas chromatograph  used
    was a Beckman CG-5.

2.  Analysis of Wastewaters

    While the project facility was being constructed, the  mixed liquor
    suspended solids (MLSS) levels in the contact  aeration tanks  of  the
    treatment plant were brought  up to  and maintained at 2500  ± 500  mg/1
    in order to have reasonable concentrations of  biologically active
    solids in these tanks.   Many  analyses were then  conducted  on  the
    wastewater flowing into, through and out  of  the  plant  in order to
    ascertain the nature of the raw wastewaters  and  the operational
    effectiveness of the various  treatment plant sections  as well  as
    of the whole plant itself. These analyses,  determined the baseline
    conditions of the project and are discussed  in some detail below.

    a.  Sanitary Chemical Analyses

        On each day of a seven-day period in  July  1969, grab samples
        of the raw sewage and primary effluent were  collected  at  0100,
        0200, 0300, 0400, 0500, 0600, 0800, 0900,  1100, 1500,  1700,
        1900, 2100, 2300, and 2400 hours and  grab  samples  of the  final
        effluent of treatment plant section 3 (subsequently known as
        System B) were collected  at 0300, 0600,  0900, 1200, 1600,  2000,
        and 2400 hours.   Immediately after each  sample was collected, its
        conductivity, dissolved oxygen concentration, and  pH were measured.
        The samples were then acid preserved  and,  as soon  as it was  practi-
        cal, their COD's and GDI's (oxygen demand  indices) were determined
        with their colors being noted;  in addition,  the BODs's of those
        samples of (1) the raw sewage that were  collected  between 0100
        and 0700 hours,  (2) the primary effluent that were collected
        between 0200 and 0800 hours, and (3)  the final effluent that
        were collected at 0300, 0600, 0900, and  2400 hours were measured.
        The BOD, COD, and ODI measurements gave  exceptionally  high values
        for the raw wastewater samples collected during the early morning
        hours of the week days.  The COD and  BOD values of the raw waste-
        water samples obtained during these times  generally exceeded 1000
        and 400 mg/1, respectively, with recorded  highs: of 1750 and  840
        mg/1, respectively.  During other times  over the sampling period,
        BOD's values were less with the lowest values usually  falling in
        the 30 to 40 mg/1 range,  while COD's  values  were also  lower  and
        dropped down into the 200 to 400 mg/1 range.  Thus, the raw
        wastewaters entering the  treatment plant on  week days  were found
        to vary greatly in their  pollutional  strength, not only from day
        to day but from hour to hour.  On the other  hand,  the  BOD and COD
                                    28

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values of the grab samples collected on the weekend that fell
within the 7-day sampling period did not vary as markedly.  Most
of these BOD values were in the range of 30 to 120 mg/1; and most
of the COD values, in the range of 130 to 400 mg/1.  The BOD, COD,
and ODI results obtained on the primary effluent grab samples were
also higher for those samples collected during the week day
morning hours than for those samples collected at other times;
however, their peak values were never as high as the peak values
obtained for the raw sewage samples and they lagged the raw
sewage peak values in time by about two to three hours yet per-
sisted for longer periods to show (as would be expected) that
the slug loads that hit the plant during the morning hours were
smoothed out somewhat as they passed through the primary tanks.
A plot against collection times of ODI values obtained on samples
of primary effluent that were grabbed hourly over seven consecutive
days is shown in Figure 3.  This plot dramatically illustrates the
slugging of the aeration basins of the plant on week day mornings
with a waste flow containing appreciable quantities of oxidizable
materials.  The BOD and COD results obtained on final effluent
grab samples were in the ranges of less than 10 to 150 mg/1 and
120 to 600 mg/1, respectively.

The chlorine demands of the raw sewage samples grabbed nearly once
each hour over two separate 24-hour periods were determined for 30-,
45-, and 60- minute contact times.  During the first of the 24-hour
sample collection periods, the raw waste flow exhibited the early
morning peak in ODI values, while during the second of the 24-hour
periods the waste flow did not; however, the chlorine demands for
both periods, even over the early morning hours, did not offer
appreciably, running between 5 and 15 mg/1 for 30 minute contact
times.  Chlorine demands at 45- and 60- minute contact times ran
only slightly higher than those at 30-minute contact times.

Over another seven-day period, grab samples of the raw sewage,
primary effluent, and Section No. 3 final effluent were collected
hourly and composited daily, with sample preservation being
effected during daily compositing period by refrigeration.  The
daily composites were then analyzed for their total phosphorous
concentrations  (soluble and soluble plus insoluble), oil and
grease concentrations (by the Freon extraction procedure), COD's
and BODs's (soluble and soluble plus insoluble), dissolved solids
concentrations, suspended solids concentrations, specific con-
ductances, chloride ion concentrations, pH's, and oxygen uptake
rates.  A similar set of daily composites spanning a third seven-
day period were collected and analyzed for their ammonia nitrogen
concentrations, organic nitrogen concentrations, nitrite nitrogen
concentrations, COD's, sulfide concentrations, sulfate concentra-
tions, total sulfur concentrations (sulfide, sulfite, hydrolyzable
sulfonate, and sulfate sulfur as sulfate), specific conductances,
                                29

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co
o
        22 i—
        20
        18
        16
        14

      5 10
      o
                                 J	L
               J	L
               J	L
                J	L
               J	L
             6   12   18
              WEDNESDAY
6   12   18
 THURSDAY
6   12
  FRIDAY
 6   12   18
  SATURDAY
Time (hours)
6   12   18
  SUNDAY
6   12   18
  MONDAY
  12   18
TUESDAY
             Figure 5.   Oxygen  Demand  Indices  (GDI's)  of Grab Samples of Primary  Effluent Collected
                          over  the period of October 18  to October 24,  1967

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and pH's.  The significant findings obtained from these analyses
are summarized below:

(1)  The BOD values of the composite samples of the raw sewage
     ranged between 200 and 300 mg/1 and the BOD values of the
     composite samples of the final plant effluent (i.e., Section
     3 effluent), from 45 to 150 mg/1 with daily BOD removals
     averaging about 70%.  The soluble BOD's of all the samples
     regardless of type—i.e., raw sewage, primary effluent or
     final effluent—were generally 70% of the total BOD's of
     the samples, although this percentage often varied quite
     widely among samples of even the same type.

(2)  The concentrations of total phosphorus (expressed as ortho-
     phosphate) in the unfiltered samples fell in the range of
     20 to 40 mg/1.  The phosphorus concentrations in the filtered
     samples were not much less than the phosphorus concentrations
     in the corresponding unfiltered samples, thereby revealing
     that most of the phosphorus in the different wastewater
     samples was in solution.

(3)  The chloride concentrations in the samples ranged between
     48 and 75 mg/1 and averaged 61 mg/1.

(4)  Significant sulfide concentrations—0.1 to 3 mg/1—were
     present in nearly all samples.
                                        /
(5)  The total sulfur concentrations in the samples ranged
     between 80 to 120 mg/1 as sulfate.

(6)  The concentrations of ammonia nitrogen in the raw wastewater
     samples were about 20 mg/1 while the concentrations of
     organic nitrogen were about only 5 mg/1.  The relatively
     high ratio of ammonia N to organic, it is believed, is
     indicative of considerable decomposition of proteinaceous
     materials occurring in the raw wastewaters before these
     waters reach the treatment plant.

(7)  Only rarely were there not detectable concentrations of
     nitrate or nitrite in any of the samples.  Generally, all
     the samples including those of the raw sewage had nitrate
     and nitrite; but, the concentrations of these anions in
     terms of nitrate or nitrite nitrogen were never greater
     than 0.2 mg/1; and, in many of the samples, these concen-
     trations were only at trace levels.  In addition, the
     effluent samples consistently contained smaller concentra-
     tions of nitrate and nitrite than did the corresponding
     samples of raw sewage and primary effluent.
                               31

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 (8)   The  specific  conductances of  plant  Influent and primary
      and  secondary effluent  samples composited over a single
      24-hour  period varied little  from one another; and, over
      the  entire week of  sampling,  specific conductance values
      of daily composited samples fell in the rather narrow  range
      of 180 to 390 pmhos/cm  with 309 pmhosAim being the typical
      value.

 (9)   Over the sampling period, the pH values of raw sewage
      samples  averaged 7.2; the primary effluent samples, 7.2;
      and  the  final effluent  samples, 7.4.

(10)   The  levels of suspended solids in both the raw sewage  and
      the  final plant effluent varied greatly from day to day.
      The  suspended solids concentrations in 24-hour composite
      samples  of raw sewage ran as  low as 58 and as high as  986
      mg/1 and in  24-hour composite samples of the final effluent,
      from 22  to 196 mg/1. The volatile  portion of the influent
      suspended solids also varied, ranging from 70 to 100%.
      Typically, the plant influent contained about 250 mg of
      suspended solids per liter while the plant effluent had
      about 95 mg  per liter.   The regular occurrence of high
      suspended solids concentrations in  the final effluent was
      a major  operational  problem of the  treatment plant and,
      except for the extremely frequent production of malodorous
      hydrogen sulfide gas by the treatment plant, was the most
      obvious  deficiency  in the performance of the plant.

      In the baseline study,  not only were sulfide concentrations
      of significant proportions found in grab and composite
      samples  taken from  various points throughout the treatment
      plant; but,  by means of lead  acetate impregnated filter
      papers suspended over the wastewaters at different points
      in the plant, hydrogen  sulfide gas  was found to evolve
      almost continuously from the  wastewaters that were dis-
      charging over the effluent weirs of the primary and final
      settling tanks—as  well  as from the mixed liquors that were
      being aerated in the sludge reaeration and contact aeration
      tanks.

      In extending  the routine wastewater testing program of the
      treatment plant, sulfite tests on grab samples of the  raw
      sewage were made regularly throughout the period of project
      baseline study. These  tests  were closely followed because
      of the high  immediate oxygen  demand that sulfites exert and
      because  of the quite large sulfite  concentrations that were
      reported to  have been found entering the Hagerstown treat-
      ment plant prior to the initiation  of the research project.
      The  tests showed that during  the baseline study sulfites
                               32

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            were^often  present  in the raw wastewaters  for  short  periods
            of  time,  and  that their concentrations  generally  ranged  from
            0 to  3 mg/1.   Although sulfite levels as high  as  7 and 10
            mg/1  were found,  no concentrations  of sulfite  were detected
            that  were as  high (i.e., >25 mg/1)  as many of  those  reported
            prior to  the  development of the project plan.

            In  addition to the  dissolved oxygen analyses performed on the
            various wastewater  samples, dissolved oxygen profiles of
            various plant sections were run with dissolved oxygen measure-
            ments being made  in situ by means of a  Weston-Stack  dissolved
            oxygen meter.  These measurements were  made throughout the
            treatment plant every 8 hours over  a 7-day period.   Generally,
            extremely low dissolved oxygen levels were found  to  exist
            throughout  the entire treatment system. Incoming wastewaters
            and the wastewaters in the primary  tanks were  found  to have
            no  dissolved  oxygen, except rarely, then only  in  trace
            amounts.  The wastewaters entering  the  aeration tanks often
            had slight  amounts  of dissolved oxygen  as  a result of having
            been  discharged over the weirs of the primary  tanks.  Dissolved
            oxygen  levels in  the aeration tanks were usually  in  the  order
            of  tenths of  a mg/1 although they occasionally did reach
            1 mg/1  or more.  The wastewaters in the final  settling tanks
            usually contained no oxygen also but upon  being discharged to
            the receiving stream did pick up some oxygen.   As a  rule,
            dissolved oxygen  levels ran somewhat, though not  appreciably,
            higher  on the weekend than on the week  days of the 7-day
            study period.

3.   Oxygen Uptake Measurements

    The rates  at which the dissolved oxygen concentrations  would  be
    depleted in  well  aerated 24-hour composite samples  of raw  sewage,
    primary effluent,  and  final  effluent was investigated.   It was found
    that dissolved oxygen  levels in well aerated (oxygen saturated) raw
    sewage and primary effluent samples that were collected on week days
    would drop from  7  mg/1 to  less than 0.5 mg/1 in  25  to 35 minutes  while
    in that same length  of time the dissolved oxygen concentrations in well
    aerated final  effluent samples that were also collected on week days
    would drop by only about 30%.  It was also found that weekend samples
    of raw sewage, primary effluent, and final effluent consumed  oxygen
    at appreciably lesser  rates than their week  day  counterparts.

    A number of  mixed  liquor samples were collected  over the preliminary
    analysis task period of the project and the  rates at which they took
    up oxygen  were also  measured, the measurements being made  by  means
    of Warburg Apparatus (Aminco, 18-station Model). Samples  taken from
    the tail end of the  sludge reaeration tank of Section No.  3 had
    oxygen uptake rates  of 5 to 9 mg 02/g MLSS/hour  and samples taken
                                     33

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    from the head end of the contact aeration  tank  of  the  same  section
    had oxygen uptake rates  of between 10  and  20  mg 0£/g MLSS/hour.
    Besides these measurements, several  1:1  mixtures of sludge  re-
    aeration tank mixed liquor and  composite raw  sewage samples collected
    on week days  were examined and  they showed healthly oxygen  uptake
    rates of around 20 mg Oo/g MLSS/hour.   It  is  felt  that these high
    uptake rates  displayed By the mixtures strongly indicate  that the
    wastewater used in the mixtures, which seemed typical  of  the raw
    sewage entering the treatment plant on week days during the project,
    contained no  toxic and/or inhibitory substances.

    !.._ rt'uiburg Apparatus was also  used to check  for the possible presence
    in the wastewater of toxic or inhibitory materials in  another way:
    The 5-day BOD of a raw wastewater sample that was  composited over a
    24-hour week  day period  was determined by  both  the standard dilution
    method and the direct method, which requires  the Warburg  Apparatus.
    Both methods  gave BODs values for the  sample  that  were in good
    agreement. Thus, dilution of the sample (which was 100:1 in the
    dilution method) had no  major effect on its BODs value.   Consequently,
    it is reasonable to assume that in all  likelihood  toxic and inhibitory
    materials, if present in the raw sewage, were not  present in sufficient
    amounts to affect biological activity.

4.  Microscopic Examinations of Plant Biota

    As a part of  the preliminary analyses  that were performed,  microscopic
    examinations  were made of the wastewaters  from  active  parts of the
    Hagerstown treatment plant.  These examinations revealed  that the
    outstanding feature of the zoogleal  floe mixes  from the aeration tanks
    of the treatment plant was the  universal presence  of filamentous
    "sulfur bacteria" growing among relatively small and stringly zoogleal
    bacterial masses (see Figure 3).  These filamentous sulfur  bacteria
    were of the type commonly found in activated  sludges receiving hydrogen
    sulfide, mercaptans, and other  reduced sulfur compounds.  The filamentous
    bacteria were readily distinguishable  by their  motility--they exhibited
    bending and creeping movements, much like  the blue-green  algae,
    Oscillatoria.  They consisted of a series  of  nearly cylindrical  cells,
    aligned in a  common capsular sheath.  Refractile masses of  elemental
    sulfur appeared at intervals in the filaments.   It is  generally
    believed that these sulfur deposits represent the  end  product of the
    oxidation of  hydrogen sulfide to sulfur and that the reaction is not
    carried further by the bacterial group.

    Besides being found in the mixed liquors,  the filamentous sulfur
    organisms were also observed in the raw sewage, and in the  primary
    tank and final tank effluents.   It is  general experience  that solids
    bearing filamentous bacteria settle poorly.  Consequently,  it was
    felt that if  these sulfur organisms could  be  eliminated from the
    treatment system by destruction of hydrogen sulfide and other reduced
    sulfur compounds serving as their source of energy, a  more
                                    34

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                                                  ..

                                                                             '* .
                                                                             •-»»•
                                                        > ?$~*       >•
Figure 6.   Photomicrograph of the Aeration Tank  Mixed Liquors, Taken during the
           Baseline Study and Showing Filamentous  Sulfur  Bacteria Containing
           Globules of Sulfur and Growing among  Masses of Zoogleal Bacteria

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    readily settleable floe would be generated and better manage-
    ment of the treatment process would be possible.   It was hoped, of
    course, that the pretreatment schemes using oxidants would achieve this
    this destruction of reduced sulfur compounds.

    It is interesting to note in view of the considerable quantities of
    hydrogen sulfide that were in the wastewaters  that the microscopic
    examinations that were made did not reveal the presence of micro-
    organisms of the type that produce hydrogen sulfide.  However,  it is
    believed that they were indeed in the plant, perhaps attached to the
    sidewalls of the various tanks.

5.  Color Measurements

    As another part of the baseline study, many wastewater samples  were
    collected over a four-day period from three sections of the Hagerstown
    water treatment plant.  The four-day period ran from a Thursday
    through a Sunday and the hourly and multi-hourly collections yielded
    representative grab sample of raw waste, primary effluent and final
    effluent, as well as 24-hour composites of these waters.   The samples,
    over 90 in all, were analyzed to determine the color characteristics
    of wastewaters (which are usually intensely colored as a result of
    the dye wastes they contain) and how these characteristics changed
    as the wastewaters flowed through the plant.

    The following observed trend and general conclusions were derived
    from the experimental data:

    a)  Typical color data in final form appeared  as  follows:

Type      Date    Time    % Luminance          Hue	    % Purity

Raw       1/22    1100         84         greenish-yellow        5

Primary   1/22    1300         85         greenish-yellow        4

Final     1/22    1800         98         greenish-yellow       <1

Raw       1/23    1500         89         greenish-yellow        8

Primary   1/23    1700         94         yellow                 2

Final     1/23    2100         97         yellow-green           1

    b)  Part (a) typifies the general trend in the samples.  The hues of
        the samples seldomly changed significantly from raw to final and
        over 90% of them fell into the blue-green  to yellow range of the
        spectrum.  In the majority of cases, the degree of brightness was
                                   36

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        relatively high and increased from raw to final, while the
        corresponding values for color saturation were very low and
        decreased that same sequence.

    c)   Weekend grab samples were almost exclusively in the greenish-
        yellow range.  Their percent purity and percent luminance
        indicated a somewhat better quality to the waste.  This probably
        is attributable to lesser volumes of dye wastes discharged into
        the system at this time of the week.

    d)   The 24-hour composites displayed an overall lack of change from
        sample to sample.  Only three of the eleven composites were not
        greenish-yellow, these three being green, blue-green,  and yellow
        respectively.  Here again, the percent purity was very low in  all
        the samples.

6.  Detection of Volatile Organics

As part of the investigation of treatment plant performance and wastewater
characteristics, gas chromatography was employed to trace certain organic
pollutants in the wastewaters through the various sections of  the plant
and to "fingerprint" the-various industrial wastes entering the plant.
Wastewater samples used in this work fell into three groups:

    (1)  Hourly grab samples taken from manholes near industries
         suspected of discharging high strength, extremely noxious,
         or toxic wastes into the city's sanitary sewerage system.
         The sampling points were chosen such that the wastes  from
         any one particular industry would be isolated from those
         from any other industry.  Some of these samples were
         collected from 0000 (midnight) to 0800 hours as part  of
         an effort to locate the source or sources of the heavy
         load of high oxygen demanding materials that were entering
         the Hagerstown treatment plant during the early morning
         hours, week days.

    (2)  Twenty-four-hour composite samples of the plant influent
         collected each day of a seven-day period, which included
         week day and weekend wastewater representation.

    (3)  Twenty-four-hour composite samples of the plant influent,
         primary effluent, and final effluent collected at random
         times, weekly.

         The chromatograph obtained on the grab samples of the wastewaters
         that were essentially industrial in nature (groups (1) samples)
         exhibited, as a whole, some 19 different peaks exclusive of the
         water and air peaks common to all chromatograms made  on aqueous
         samples.  It was evident from an analysis of the data that
         particular peaks or pollutants could be associated with parti-
         cular industries.


                                    37

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         Chromatograms of the group (2)  samples,  the 24-hour composites
         of the plant influent,  distinctly showed at least six of the
         peaks found in the chromatograms  of the  group (1) samples.   One
         especially predominate  peak was traceable to wastes discharged
         by a textile dyeing and printing  plant by correlation with  the
         chromatographic information obtained on  the group (1)  samples.
         The other major peaks were attributable  to the textile dyeing
         and printing plant also, and to a creamery.   Other constituents
         appeared in the group (2)  composites that were not detected in
         the group (1) samples;  however, they were relatively minor.
         On the other hand, certain of the chromatographically detected
         components of the group (1) samples were not found in the group
         (2) samples, perhaps as a result  of being reduced in concentra-
         tion below G-C detection limits by dilution in the sewer system
         and by sample compositing.  The group (2)  samples collected on
         week days contained a greater number and larger amounts  of
         chromatographable materials than  did the group (2)  samples
         collected on the weekend,as had been expected.

         The chromatograms of the 24-hour  composite samples  of plant
         influent, primary effluent, and final  effluent (group (3)
         samples) showed some of the same  peaks as  the chromatograms
         of the samples of groups (1) and  (2).  In  following the  chroma-
         tograms of the group (3) samples  from plant influent to  effluent,
         it was plainly evident  that there were gradual  decreases in  the
         areas under some of the peaks,  indicating  decreases in the
         quantities of the wastewater components  yielding the peaks,
         and certain influent chromatogram peaks  were completely  absent
         in the chromatograms of the final  effluent samples.   These  de-
         creases and disappearances may have been due to one or a
         combination of the following factors:

         (1) the pollutants were actually  degraded  in the treatment
             plant,

         (2) the pollutants were diluted in concentration as they
             passed through the  plant,

         (3) the pollutants, being volatile, were swept from the
             wastewater by aeration, and

         (4) the pollutants were absorbed  by suspended solids.

B.  Survey of Industrial Plant

1.  Introduction

    Beginning shortly after the  project was initiated, a limited survey
    of a select number of industrial plants located within the city  of „
    Hagerstown was conducted to  discover the types  and amounts of wastes
                                   38

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these plants were discharging into the city's sanitary sewerage
system.  Since it was felt at the beginning of the project that
the textile dyeing plants wastes and the wastes from the metal
finishing and plating plants were imposing the greatest diffi-
culties on the treatment plant, the textile dyeing and metal
finishing and plating plants were the primary target of the
survey effort.

Preparatory to the effort, a cursory literature study of modern
textile dyeing and metal finishing and plating practices was
carried out to familiarize the survey personnel with these
practices.  Also, a list of the various textile dyeing plants
as well as other types of industrial plants utilizing the city's
sewerage system was compiled, and waste-discharge-questionnaire-
and-record booklets for issuance to the industries were prepared.
From the compiled list of industries, key industries were selected
to be surveyed.  These industries then were sent a letter from the
Mayor's office, explaining in general the project and in particular
the planned survey and requesting the cooperation—in fact, the
active participation—of these industries in the investigatory
effort.  These industries were screened further through actual
in-plant visits by members of the project team; and, on the basis
of plant size, nature of the wastes discharged, and the volumes
of the discharges, nine of the candidate industries were finally
chosen for the complete survey, the rest being dropped from further
consideration.

Following the selection of the nine industries, top management
personnel in each of the industries were given copies of the
questionnaire—record booklets with instruction for their completion
and the in-depth survey of these industries were begun.  The  purpose
of the record booklets was to obtain in written form from each in-
dustry project pertinent information on plant practices and to
establish in each industry a program of recording daily over the
survey period the types and amounts of chemicals consumed and
materials wasted during each day of operation.  A set of the  forms
contained in the booklets may be found in the appendices of this
report.

Over the survey period, which initially was allotted sixteen weeks
of project time, a series of visits were paid by various members of
the project team to each of\the industries.  During these visits,
data recorded in the booklets were collected; plant operations were
reviewed; supplemental information on plant waste disposal practices
were secured; and, to promote the spirit of cooperation, questions
about the project from plant personnel were encouraged and, when
raised, openly answered.  Without exception, each industry contacted
responded to the survey undertaking with expressions of interest in
the project and of willingness to participate in the survey.   The
favorable responses are attributed in part to the fine public relations
                                   39

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efforts conducted by the city in regard to the project and the
realization by the industries of the real  necessity for the
project, including the industrial survey.

Industries Surveyed and Survey Data Obtained

The industries surveyed and the survey data obtained are
presented below:

(a)  Mack Trucks, Inc. - 1999 Pennsylvania Avenue, Hagerstown, Md.

     This plant of Mack Trucks, Inc., employ approximately 3500
     persons, working in three shifts, seven days a week.   It has
     about 1.02 million square feet of manufacturing area  and
     produces the complete power train—engines and transmissions—
     for heavy duty trucks.

     Prior to the project, this plant reportedly, was responsible
     for several sizeable oil dumps into the city's sewerage system
     that resulted in large quantities of oil  reaching the municipal
     sewage treatment plant and severely impairing the performance
     of the treatment plant for periods of several days.  However,
     just before the project was begun, the company installed and
     placed into operation two No. 150 Josam Oil  Interceptors to
     prevent further such incidents.

     The basic manufacturing operations of the Mack plant  are cutting
     and heat treatment of metal engine parts.  No metal pickling or
     plating operations are carried out.  The oil necessary for the
     cutting operations is prepared and stored at a single location
     in the plant and pumped from that location through a  piping
     system to the various metal cutting machines in the plant.
     Waste oils from the cutting machines are collected in four
     sumps situated strategically throughout the plant and then
     pumped from the sumps into a single waste oil storage tank.
     Ultimately, the waste oils are pumped from the storage tank
     into a tank truck for reclamation or disposal elsewhere.

     Machined engine parts are washed free of excess oils  in large
     industrial washers.  There are 52 such washers in the plant and
     they use Mack 326 and 328 Alkaline Cleaners in the concentration
     of 1 to 3 oz of the alkaline base material to one gallon of water
     with approximately 180 to 360 Ibs of the Mack 326 Cleaner and
     700 to 1500 Ibs of the Mack 328 Cleaner being consumed each week.
     Once a week, generally between midnight and 8:00 a.m., the
     cleaner solutions are discharged from the washers into the city's
     sanitary sewerage system.  One third of the industrial washers
     are equipped with oil skimmers; the rest have drip drags which
     aid reportedly in oil removal.
                                  40

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The plant contains two recirculating cooling water systems, the
waters of which are treated for corrosion control with chromate
(25 to 50 mg/1), sulfuric acid and sodium polyacrylate.  Approxi-
mately, 70 Ibs of chromate (Dearborn 533), 2.6 Ibs of 66° Be
sulfuric acid and 9 gallons of sodium polyacrylate are used
weekly in the treatment of the waters.  In addition, the cooling
waters are also treated with sodium pentachlorophenate (Dearborn
711), a slimicide, of which about 21 Ibs are used weekly.  The
"blow down" from these systems is set at approximately 2%, which
amounts to a constant flow of about 15 gpm from one system and
10 gpm from the other.  These blow-down discharges enter the
city's sanitary sewerage system directly.  However, any excess
cooling waters from the boilers that supply hot water to the
previously mentioned industrial washers are discharged into
the storm drain system of the plant.

In the plant, certain machined metal parts undergo heat treatment
for case hardening.  Two different heat treatment processes are
used.  In one process parts undergo carburizing in a furnace.
Some of these parts, immediately after removal from the carburi-
zing furnace, are automatically oil quenched, then rinsed with
water, which subsequently is wasted to the city's sewerage
system.  Other parts, after removal from the carburizing furnace,
are held in a die press to hold their shapes until sufficiently
cool, then subjected to an oil quench and finally a water quench.
There are about one dozen water-quench-bath vessels in the plant
for this process.  These are 5' x 5' x 2.5' in size and, depend-
ing on the-degree to which they are used, are generally dumped
once a month into the sanitary sewerage system.

In the second heat treatment process, which involves liquid
carburizing with the use of "Cyanobrik" (97% sodium cyanide
briquettes), there are three baths; namely:  a molten salt
bath (Park Chemical Company "Nu-Sal", neutral salt, m.p.
1230°F), an electrolytic salt quench (Park Chemical Company
"Thermo-Quench," m.p. 288°F), and a salt bath water quency
(AJEM-33-S).  The salt bath water quench is contained in only
one vessel, whose dimensions are 2' x 2' x 1.5'.  There is a
continuous overflow from this vessel to the drain and the
sanitary sewerage system; this overflow amounts to about 25
gallons per day.  From 620 to 920 Ibs of the AJEM-33-S material
is used weekly to maintain the salt content of the quench bath.

Concerned about cyanide being introduced into the city's sewerage
system as a result of the above heat treatment process, the
project team sampled and tested the wastewater discharges of>the
Mack plant during the survey of the plant.  These tests revealed
no significant levels of cyanide in the discharges.
                               41

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    There  is a  research and development and engine testing area in
    the  plant where engines are assembled, run, studied and dis-
    assembled.  The floor drains  in this area lead to the previously
    mentioned oil separators.  Waste oils recovered by the separators
    are  pumped  into one of two waste oil storage tanks.  One tank_is
    for  oils to be carted away; the other is for oils to be reclaimed.
    Waters from the separators are pumped into the sanitary sewerage
    system.

    The  plant has its own storm drain system, which surrounds the
    entire Mack facility; and, this system discharges into an
    earthen dam, which can store  nearly 1.5 million gallons of
    stormwater. This drain system is not connected in any way to
    the  city's  sewerage system.

    The  plant wastes to the city's sewerage system an estimated
     400,000 gallons of water  daily.

(b)  Pangborn Corporation - Pangborn Boulevard, Hagerstown, Md.

    The  Pangborn Corporation  is a wholly-owned subsidiary of the
    Corborundum Company, Niagara  Falls, New York.  The Hagerstown
    facilities  of the corporation employ more than 1200 people and
    are  devoted to both engineering and manufacture of complete
    systems for cleaning, deburring, descaling, peening, etching
    and  finishing the surfaces of metals and metal components and
    complete systems for industrial air pollution control.  The
    manufacturing facilities  consist of foundry, machine-shop,
    metal-working, wood-working,  and assembly plants.

    Essentially all manufacturing operations performed in the
    Hagerstown  facilities of  the  Pangborn Corporation are "dry."
    Treatment of metals is done solely mechanically by means of the
    company's own devices--"Rotoblast" and air blast machines--
    consequently there are no chemical treatments, such as pickling,
    with highly acidic or alkaline liquid waste.  In some metal
    cutting and drilling operations, oils and other lubricants are
    used;  but,  these substances are employed in only limited
    quantities; and, when they are spent, they are disposed of by
    being  poured over the gravel  bed of the railroad spur that
    serves the  Pangborn complex.  This method of disposal is practiced
    primarily for weed control and, reportedly, there are never enough
    spent  lubricants for this purpose.

    There  are several air scrubbers for dust control located in
    various sections of the Pangborn facilities.  The waters in
    these  units are continuously  recirculated (with evaporation
    losses continually replaced), and these waters are never
    discharged  to the city's  sewerage system.  The sludges of fine
    particulate matter that collect in the scrubbers are continuously
                                  42

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     and  automatically removed from the scrubbers  by mechanical
     conveyor systems  and deposited in drums,  which, when  full,
     are  carted away from the Pangborn site for ultimate disposal
     of the sludges elsewhere.

     Because all  the manufacturing operations  of the Pangborn
     facilities in Hagerstown are, in fact, dry, these  facilities
     do not discharge any "industrial wastewaters" of any  sort
     into the city's sewerage system.

(c)   Potomac Dye and Print Corporation - 1000  Florida Avenue,
     Hagerstown, Maryland.

     The  Florida Avenue plant of the Potomac Dye and Print Corporation
     is one of two textile dyeing plants owned by this  corporation  in
     the  City of Hagerstown.  The second plant is  located  on Franklin
     Avenue in the city and its operations are reviewed subsequently.
     The  Florida Avenue plant employs about 65 people and  occupies
     approximately 51000 square feet of space.

     Primarily, the plant roller prints synthetic fabrics  with a water
     phase print system.  The print vehicle is mineral  spirits (Varsol)
     in water emulsion; and, all dye colors, emulsions, and resins  used
     in the print colors are water soluble until they are  dried and
     cured on the printed fabric in the printing process.   Varsol
     comprises about 50% of any dye mixture.

     In addition to several roller type printing machines, which
     incidentally use copper rollers that are etched with  the print
     designs elsewhere, the plant contains four dye jigs,  one dye
     box (2000-gallon capacity) and a large fabric washer  with a
     stream dryer.  The four dye jigs and the dye box are  used for
     cloth "boil-off" and the washer-dryer for washing  and drying
     back greige (cotton duck) and print cloth.

     Typically, about 15500 yards of back greige and 37000 yards of
     fabric to be printed and washed and dried each day.   Nearly 90%
     of the wastewaters discharged by the printing plant  in the city's
     sewerage system are generated by the washer-dryer.  In the
     washing process, only two chemicals are used—sodium  pyrophosphate
     and sodium metasilicate.  Approximately,  162 Ibs and  49 Ibs of
     these chemicals, respectively, are employed daily.

     The entire plant consumes a total of about 112000  gallons of
     water a day, of which about 102000 gallons are ultimately
     discharged to the sewer and 10000 gallons are lost by evapora-
     tion in the cloth washing and drying operation.
                                   43

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              Table 1.  CHEMICALS AND DYESTUFFS CONSUMED BY THE FLORIDA AVENUE PLANT
                                OF THE POTOMAC DYE AND PRINTING CORPORATION

Chemical
Chemical Division
Press Cakes (all colors)
Monsanto Serox DJ (Alkylaryl
Polyoxyethyle Ether)
Antifoam B
Pontamine White BT
Potassium Tripolyphosphate
Titanium Titanox A-WD
(Titanium Dioxide)
Methacel
China Clay
Rohm & Haas Rhoplex HA-8
Purpose
Pigments for Color Dispersions
Emulsifier
Anti foaming Agent
Optical Bleach
Dispersing Agent
Titanium Pigment
Thickener
Filler
Fabric Binder
Quantity
In 84 Days
8700 Ibs
1870 Ibs
485 Ibs
54 Ibs
46 Ibs
2700 Ibs
2500 Ibs
2410 Ibs
3875 Ibs
Consumed
Per Day
_ _ m.
	
	
	
	
___
	
	
	
(Acrylic Emulsion)

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                                                 Table  1.   continued
                   Chemical
                                            Purpose
                                                                                     Quantity Consumed
                                     In 84 Days
                  Per Day
-ts>
on
Mineral Spirits (Varsol)
Dow Latex 881
Polyacrylamide
Polyacrylate
Sodium Lauryl Sulfate
Monsanto Lytron 822
Aqua Ammonia
Butylated Mel amine
Dipentene
Monoethanolamine
Thickener L
RWA 325
Diethylene Glycol
Solvent
Latex Binder
Dispersing Agent
Dispersing Agent
Wetting Agent
Emulsifier
Cleanser
Fabric Finish
Solvent
Dispersing Agent
Thickener
Dispersing Agent
Dye Solvent
49000 Ibs
 9000 Ibs
  100 Ibs
   80 Ibs
 4015 Ibs
  610 Ibs
 2955 Ibs
 4325 Ibs
  780 Ibs
   95 Ibs
 2800 Ibs
 649  Ibs
 435  Ibs

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                                               Table 1.   continued
CT>
                 Chemical
Purpose
                                                                                  Quantity Consumed
In 84 Days
Per Day
Print Division
Rohm & Haas Paraplex G60
Dow Antiform B
Ammonium Sulfate
Mineral Spirits (Varsol)
Dow Latex 881
Natural Latex
Trimethylol Mel ami ne
Acetone
Back Greige and Print Cloth
Sodium Pyrophosphate
Sodi urn Metasi 1 i cate

Print Softener
Anti forming Agent
Catalyst
Solvent
Binder
Finishing
Fabric Treatment
Solvent
Washing
Cleanser
Cleanser

1090 Ibs
1600 Ibs
500 Ibs
2100 Ibs
20800 Ibs
7300 Ibs
920 Ibs
21 Ibs

13600 Ibs
8300 Ibs

13 Ibs
191 Ibs
6 Ibs
250 Ibs
247 Ibs
87 Ibs
11 Ibs
1/4 Ib

162 Ibs
99 Ibs

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    The plant has  nearly  one  floor  drain  for  every  500  square feet
    of floor space.  These  drains lead  to three  below-the-floor
    sumps whose  effluent  lines  eventually join into one line which
    empties into the city's sewerage system.

    The plant has  its  own laboratory (referred to as  the  "Chemical
    Division" of the corporation) for preparing  the color cakes and
    color dispersions  used  in the textile printing  operations of
    the plant as well  as  plants of  other  companies.   In general,
    it is not practical  to  give typical values for  the  quantities
    of chemicals and dyestuffs  utilized in the preparation of the
    colors  and  in  the  textile printing  operations of  the  plant on
    a daily basis  since  the printing operations  vary  considerably
    from day  to  day with  respect to the types and amount  of fabrics
    printed and  colors used.   However,  the amounts  of the various
    chemical  and dyestuffs  consumed in  all plant operations over
    the 83  plant operating  days that comprised the  plant  survey
    period  were  recorded  and  are tabulated on the next  page; and,
    in those  instances,  where daily consumption  values  are meaning-
    ful these date are given  also.

(d)  Potomac Dye  and Print Corporation - 367 East Franklin Street,
    Hagerstown,  Maryland.

    This  is the  second of the two plants  of the  Potomac Dye and
    Print  Corporation  in  the  City of Hagerstown; and, it  has about
    69 employees.

    The plant dyes synthetic  fabrics (materials  of  nylon, polyester,
    etc.),  filaments  or  spun  yarns  and  some cotton  goods.  In addition,
     it  finishes  all the  cloth that  is dyed in the plant and all the
    cloth  that  is  printed in  the Florida  Avenue  Plant.

    The  "dyeing operations" of the  plant  consist of the following
    cloth  treatments:

     (1)  Washing with  plain water
     (2)   Bleaching with  hydrogen peroxide and "optical  bleaches"
     (3)   Boil-off  with detergents  and alkalies
     (4)   Dyeing with either dispersed,  acetate or direct  colors

    The application of finishes to  cloth  is done in baths which may
    contain water  and water solutions of  water repellents, resins,
    soaps,  starch, urea, dullers and softeners.   A  list of the
    chemicals used during the survey period in both the dyeing and
    finishing processes  is  presented in Table 2  on  the  following
    page.
                                  47

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               Table 2.  CHEMICALS AND DYESTUFFS  CONSUMED  BY THE  FRANKLIN STREET PLANT
                                'OF THE POTOMAC DYE AND  PRINTING  CORPORATION

Chemical
Dyeing
Disperse Acetate Dyes
Neozyme L (Enzyme)
Zinc Sulfoxalate
Hydrogen Peroxide (35%)
Sodium Hypochlorite
Mineral Spirits (Emulsion
Purpose

Dyes
Desizer
Stripper
Bleach
Machine Cleaner, Bleach
Solvent
Quantity
In 84 Days

3862 Ibs
10400 Ibs
650 Ibs
7950 Ibs
900 gals
3370 gals
Consumed
Per Day

46 Ibs
124 Ibs
8 Ibs
93 Ibs
11 gals
40 gals
  Form)
Rock Salt (Sat'd. Brine
  Solution)
Wintergreen Oil (Methyl
  Sal icylate
Trisodium Phosphate
Direct Viscose and Cotton
  Dyes
Dyeing
Carrier

Sequestrant
Dyes
88100 Ibs

  115 Ibs
44000 Ibs
 3044 Ibs
1045 Ibs
   1 Ib

 524 Ibs
  36 Ibs

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                                              Table 2.   continued
10
Chemical
Ammonia Solution
Sodium Silicate
Muriatic Acid (Hydrochloric
Acid)
Acetic Acid
Sodium Nitrite
Proctor & Gamble 01 ate Flakes
Sodium Bisulfite
Purpose
Cleanser
Detergent
Acid
Acid
Dyeing Assistant
Detergent
Reducing Agent (Anticlor)
Quantity
In 84 Days
2333 Ibs
8522 Ibs
224 Ibs
,6060 Ibs
1431 Ibs
2225 Ibs
50 Ibs
Consumed
Per Day
28 Ibs
101 Ibs
3 Ibs
72 Ibs
17 Ibs
27 Ibs
1/2 Ib
      Soda Ash (Sodium Carbonate)
      Monsanto Sterox CD
        (Polyoxyethylene Ether)
      Dow Versene 100 (EDTA)
      Finishing
      Secondary Butyl Alcohol
      Dow Antifoam B
Detergent
Detergent
Sequestrant

Solvent
Antifoaming Agent
2494 Ibs

 900 Ibs

2313 Ibs
1080 Ibs
30 Ibs

11 Ibs

28 Ibs
12 Ibs

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                                              Table 2.   continued
in
o

Chemical
Amour Arquad 2HT-75 (Quarternary
Ammonium Compound)
American Cyanamide Dicyandi amide
American Cyanamide Resin M3
(Trimethyol Mel ami ne)
American Cyanamide Resin 23 Spec.
Dow Dowicide A (Sodium o-Phenyl-
phenate Tetrahydrate)
Magnesium Chloride
White Bentonite (Natural
Aluminum Silicate)
Gum Tragacanth (Natural Gum)
Monsanto Mersize (Resin Soup)
Monsanto Syton DS (Colloidal
Purpose
Softener
Buffer for Resins
Fabric Treatment
Fabric Treatment
Preservative
Catalyst
Duller
Finishing
Detergent
Antislip Finish
Quantity
In 84 Days
2779 Ibs
2650 Ibs
21450 Ibs
6585 Ibs
50 Ibs
2350 Ibs
550 Ibs
318 Ibs
4000 Ibs
2200 Ibs
Consumed
Per Day
33 Ibs
32 Ibs
255 Ibs
78 Ibs
1/2 Ib
28 Ibs
6 Ibs
4 Ibs
48 Ibs
262 Ibs
        Silica)
      Monsanto Sterox DJ (Alkylaryl
        Polyoxyethylene Ether)
Detergent
5644 Ibs
67 Ibs

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                                              Table 2.  continued
tn

Chemical
Sodium Formate
Titanium Pigment Corp.
Purpose
Gas Fading Inhibitor
External Delustrant
Quantity Consumed
In 84 Days Per Day
16500 Ibs 196 IDS
200 Ibs 2 Ibs
  Titanox A-WD (Titanium
  Diox-ide)
Urea
Aluminum Acetate
Glacial Acetic Acid
Dupont Zelon S (Aqeous Dispersion
  of Polymer Wax)
National Starch Korfilm 50
  (Starch)
American Cyanamid Aerotex
  Reactant 1 (Cellulose
  Reactant)
American Cyanamid Cyanolube
  Softener 40 (Polyethylene
  Emulsion)
American Cyanamid Cyanolube
  Softener SB!00
 Weighter (with starch)             11400 Ibs
 Water Repellent                     350 Ibs
 Water Repellent Preparative         330 Ibs
 Water Repellent                    1117 Ibs
 Finishing                         30400 Ibs

 Wrinkle Recovery                  13387 Ibs

Softener (Resin Finishes)            8000 Ibs

 Softener                           2133 Ibs
136 Ibs
  4 Ibs
  4 Ibs
 13 Ibs
361  Ibs

159  Ibs

 95  Ibs

 25  Ibs

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     During  a  typical  operating  day,  the  plant  dyes  some  78500 yards
     of cloth  and  finishes  some  109300 yards, utilizing in  these
     processes about  130000 gallons of water.   Of  this volume of
     water consumed daily,  about 41000 gallons  are lost through
     evaporation and  91000  gallons are discharged  into the  city's
     sanitary  sewerage system.

     Before  the discharged  process wastewaters  reach  the  sewer,
     however,  they are funneled  by the floor drain system of the
     plant into an 8-foot diameter by 15-foot deep holding  tank.
     Reportedly, this tank  is  cleaned out every two months  by a
     private disposal  company.

(e)   Associated Ribbon Works - 655 N. Prospect  St., Hagerstown, Md.

     The Associated Ribbon  Works employs  33 persons  and engages in
     the dyeing of ribbon.   The  ribbon materials processed  by the
     plant are generally made  of rayon, acetate, cotton-acetate,
     rayon-acetate and nylon and vary in  widths  from  1/4  inch to
     5 inches.

     Ribbon  is handled in skein  form.  Before being actually dyed,
     it is cleaned (scoured) with hot alkalies  and detergents,
     bleached  in sodium hypochlorite  solution,  water  rinsed and then
     treated with  an  antichlor.  Some of  the ribbon so processed is
     not subsequently dyed  but is retained as white stock.  Most of
     the ribbon, however, is dyed, and aniline  type dyestuffs are
     used in the dyeing process.  These dyes are applied  to the
     ribbon  fabric in boiling  liquors that contain in addition to
     the dyes  used during the  period  this industry was surveyed can
     be found  in the  table  given on the following  page.   The plant
     does not  do any  ribbon finishing; instead,  it sends  the ribbon
     it has  processed to the Maryland Ribbon Company  plant  on
     Willow  Circle in Hagerstown for  this treatment.

     The day-to-day dyeing  operations are not carried out in accordance
     with any  regular schedule.  Consequently,  water  useage varies
     between 55000 to 102000 gallons  per  work day.  Moreover, all
     processing is done on  a batch basis  with spent  scouring,
     bleaching, rinsing and dyeing baths  never  being  regenerated;
     each bath is  dumped immediately  after each bath  operation is
     completed. The  spent  liquors are discharged  into floor trenches
     which convey  the waste to a single drain line which  discharges
     directly  into the city's  sewerage system.
                                  52

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     Table 3.   CHEMICALS AND DYES USED BY THE ASSOCIATED RIBBON WORKS
      Chemical
      Purpose
Average Daily
   Useage
Dyes
GAP Igepon T-5 (Sodium
  N-methyl-N-oleoyl
  taurate)
Sodium Pyrophosphate
Laurel Vidol Flake
  Soap (Low Titre Soap)
Laurel Laurel 65-3
Rumford Quadrofos
  (Sodium Tetra-
  phosphate)
Glaubers Salt (Sodium
  Sulfate Decahydrate)
Soda Ash (Sodium
  Carbonate)
Sodium Bicarbonate
Sodium Hypochlorite
  Solution
Sulfuric Acid, 66° Be
Sodium Bisulfite
Althouse Resamide  Extra
Althouse Resogen FWL
Brine (Sat'd. Sodium
  Chloride Solution)
Acetic Acid
Dyeing                           32 IDS
Leveling & Dispersing            13 Ibs
Agent
Water Conditioner                17 Ibs
Detergent & Dispersing Agent     10 Ibs

Leveling Agent                   13 Ibs
Water Conditioner                 7 Ibs
Exhausting Dyes onto             71  Ibs
Fabric
Cleaning & Dyeing               100 Ibs
Dyeing Catalyst                   4 Ibs
Cotton Bleach                    20 Ibs
Neutralization in Bleaching       8 Ibs
Reducing Agent (Antichlor)        6 Ibs
Stain Prevention                0.5 Ibs
Making Dyes Washable            0.5 Ibs
Direct Dyeing                    57 gals

Acidifying                        7 Ibs
                                  53

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                          Table 3.   continued
      Chemical
     Purpose
Average Daily
   Useage
Ciba Albatex BD (Sodium
  m-Nitrobenzone
  sulfonate)

TNA-5 Salt (Sodium
  Chloride)

Althouse Metachloron
Formaldehyde

Caustic Soda (Sodium
  Hydroxide)

GAP Dizopon SS837

Royce Vatrolite (Sodium
  Hydrosulfite)

Ammonia Sulfate

Tanatex Gas Inhibitor
  A (Neutral Alkylamine
  Derivative)

Muriatic Acid, 20%
  Hydrochloric Acid)

Sandoz Revatol S
  (Sodium m-Nitrobenzene
  sulfonate)

Royce Parolite (Zinc
  Formaldehyde Sulfoxa-
  late)

01 in Mathieson Textone
  (Sodium Chlorite)
Leveling Agent                  4 Ibs



Direct Dyeing                 277 Ibs


Color Migration Pre-            4 Ibs
ventative

Making Dyes Washable            3 Ibs

Cleaning Agent                 11 Ibs


Leveling Agent                0.3 Ibs

Stripping Agent                 7 Ibs


Acidifying in Dyeing            2 Ibs

Atmospheric Fading              1 Ib
Preventative


Acidifying (Resin Removal)      8 Ibs


Leveling Agent                  1 Ib



Stripping Agent               0.5 Ib



Stripping Agent (Nylon)       0.1 Ib
                                   54

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                           Table 3.  continued
      Chemical
      Purpose
Average Daily
   Useage
Tanatex X-Tan Special C
  (Sodium Alkyl Oleate
  Sulfonate)

Oxalic Acid

Aqueous Ammonia, 29%

Sandoz Sandofix WE-51
  (Cationic Resinous
  Compound)
 Corrosion Control
(w/Terbine)
 Rust Stain Removal

 Acid Neutralization

 Fixation of Colors
      0.3 Ib



      0.1 Ib

      0.2 Ib

        3 Ibs
                                    55

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(f)   Maryland Ribbon Company - 857 Willow Circle,  Hagerstown,  Md.

     The Hagerstown plant of the Maryland Ribbon Company both
     finishes and packages ribbon and related narrow fabrics
     for marketing.  Most of the 225 employees of  the plant are
     engaged in packaging and shipping of ribbon—operations,
     which do not involve the use of any chemicals of any nature
     that may ultimately end up in the sanitary sewerage system
     of the city.  About only seven plant employees are assigned
     to the ribbon finishing operations of the plant.

     For the main part, ribbon finishing is done automatically
     by machines which pass the ribbon to be treated through
     small, narrow baths of water solutions and suspensions of
     finishing materials, namely, resins and water soluble
     starches.  Most of these solutions and suspensions are absorbed
     by the fabrics in the treatment process and as the ribbons are
     dried by the steam dryer associated with the  finishing machines
     the water of the solutions and suspensions is of course driven
     off by evaporation.  As a result, the plant generates a minimal
     amount of liquid waste from its finishing operations.  In fact,
     it discharges about only 45 gallons of process water per  day
     while it consumes about 250 gallons of process water daily.
     The waste finishing liquors are discharged to the city sewer
     only between machine runs (and at the end of  each work day
     since the contents of the finishing baths are not held over
     from one working day to the next) when the finishing baths
     are flushed free of their contents.

     The plant uses only a limited number of substances in its ribbon
     finishing operations and these substances are summarized  in the
     table on the following page.
                                                      »
(g)   Victor Hosiery - 775 Frederick Street, Hagerstown, Md.

     Victor Hosiery, which has about 30 employees, both manufactures
     (weaves) and dyes nylon stockings and panty hose for women.

     Only the dyeing and associated scouring and stripping processes
     of the plant yield any industrial wastewaters.  The volume of
     wastewater resulting from these operations amounts to approxi-
     mately 1024 gallons each working day.  These  waste enter
     directly into the city's sewerage system.

     The plant dyes nearly 10000 dozen pieces of hosiery weekly.
     Dyeing as well as scouring and stripping is done in batches
     (500 dozen pieces per bath) and carried out in seven barrel
     type dyeing machines.  Upon completion of any of these
     operations, the liquid contents of the dyeing machines being
                                 56

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     used  are  dumped.   Generally,  the actual  scouring  and  stripping
     operations  are followed immediately by one or two plain water
     rinses  that are effected in the dyeing machines.   The spent
     rinse waters are of course released to the city's sewer,  also.
     During  the  20-week period over which the Victor Hosiery plant
     was surveyed, stripping, which involves the use of sodium
     hydrosulfite, was generally performed only once or twice  a
     week  although there were some weeks in which stripping was
     not done  at all or as frequently as four times (days)  a week.

     The plant uses a variety of chemicals and dyestuffs in its
     dyeing  operations.  These materials and the amounts of them
     that  are  consumed during a typical  work day are given in  the
     table on  the next page.  As noted in the table, a few of  these
     listed  materials are used only very infrequently.

(h)   W. H. Reisner Manufacturing Company, Inc. - 240 N. Prospect
     Street, Hagerstown, Maryland.

     This  industry employs 73 people and produces pipe organ supplies,
     screw machine products and, for the U. S. Navy, radar plotting
     boards.  It is housed in two separate buildings,  which are located
     adjacent to each other and are considered by the  company  as two
     separate and distinct manufacturing plants.

     The manufacturing operations of the industry are  essentially
     metal working and metal treatment although the industry does
     do some woodworking, cabinet making and electrical wiring in
     addition.  The primary metal  operations of the industry are:
     die  casting (zinc), press forming and blanking, heliarc welding
     of aluminum sheets and extrusions,  chemical cleaning  of metal
     parts,  chemical preparation of metal surfaces for painting and
     plating and the painting and plating of metal products.

     Chemical  cleaning and chemical preparation for painting and
     plating of  metal surfaces and the actual plating  of metals are
     essentially the only industrial processes of the  Reisner
     Manufacturing Company that generate wastes that are eventually
     discharged  to the city's sewerage system.  The industry consumes
     on the  average about 10000 gallons  of city water  per  day. Of
     this  amount, approximately 750 gallons are used for sanitary
     purposes and 9250 gallons for industrial purposes. Almost
     all  the water employed for industrial reasons is  used for
     cooling various plant equipment; namely, two compressors, a
     die  caster, a spot welder, a heliarc welder and a vapor
     degreaser.   The cooling waters from the heliarc welder and
     vapor degreaser are passed through  the hot water  rinse tanks
     of the  metal cleaning and plating operations.  The overflow
     from  the rinse tanks and the cooling waters from  the  plant
                                   57

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           Table 4.  CHEMICAL USED BY VICTOR HOSIERY COMPANY

Chemical
Geigy Cycoluce Yellow G
Textile Chemical
Cellutate Brilliant
Blue B Sepia
Geigy Setacyl Scarlet
RNA Sepia
Osco Chemical Auto Dye
63-50
GAP Celliton Orange GRA
Geigy Erio Black J
Geigy Tinopal WHN Liquid
Textile Chemical Assoc.
Fascadye 201 LF
HyChem Res i lube T-5
HyChem Migratex 39
Caustic Soda (Sodium
Purpose
Dye
Dye
Dye
Dye
Dye
Dye
Dye
Detergent (Scouring)
Finishing
Scouring
Scouring
Average Daily
Useage
0.5 Ib
0.5 Ib
0.4 Ib
35 Ibs
3 grams
0.2 Ib
0.1 Ib
7 Ibs
1 Ib
1 Ib
1 Ib
  Hydroxide)
Royce Sodium Hydro-
  sulfite
Asco Chemical Oscotol 300
Scholler Brothers Allo-
  Scour
Laurel  Products Vidol
  Soap Flakes
Stripping
Water Treatment
Scouring
Detergent
      1  Ib
      2 Ibs
(See Note 1 below)
(See Note 2 below)
                                  58

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                           Table 4-  continued
                                                     Average Daily
      Chemical                  Purpose                 Useage


Soda Ash (Sodium          Scouring                         0.2 Ib
  Carbonate)

Geigy Alrosol CS          Detergent (Scouring)             0.1 Ib
  (Fatty Acid Amine
  Condensate)
Notes:  1.  Allo-Scour was used on only two days during the 20-week
            period over which chemical useage data on Victor Hosiery
            was collected and on each of these days the amount of
            material  used was only 0.5 Ib.

        2.  Vidol Soap Flakes was used on only three days during the
            20-week  survey period and on these three days the useage
            was only 1, 3 and 2 Ibs, respectively.

        3.  A  total  of only  15 grams of Celliton Fast Pink FF 3BA
            were  used during the 20 week survey period.
                                    59

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       TABLE 5.  DAILY CHEMICAL USEAQE OF THE MARYLAND RIBBON COMPANY
      Chemical
      Purpose
Amount Used
   Daily
Rohn & Haas Rhonite
  R-l (Urea-
  Formaldehyde Resin)

Rohm & Haas Catalyst
  H-7 (Zinc Complex)

Althouse Polyanthrene
  KS

A. E. Staley
  Solvitose H
  (Potato Starch-
  Ether)

Colloids Vicol 175
  Vinyl  Acetate
  Copolymer)
Wetfastness & Shrinkage
Control
U-F Resin Catalyst
Wetfastness
Finish
    106 IDS



    15 Ibs


    14 Ibs


    56 Ibs
Finish
    47 Ibs
                                   60

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         equipment other than the hell arc welder and vapor degreaser
         are wasted into the city's storm sewer system.   However,  only
         the air compressors operate continuously and,  consequently,  use
         and discharge water to the sewer.  The welding,  cleaning  and
         plating operations are performed on a rather irregular  schedule
         depending, of course, on the work load of the  industry  and may
         on some days be carried out not at all or for  only a  few  hours.

         Because of the irregularity of the metal  cleaning and plating
         operations and the rather small amounts in which many of  the
         chemicals employed in these operations are used, it was
         difficult to obtain meaningful typical chemical  useage  data
         on the industry even over the rather extended  period  of time
         of the survey effort.  Fortunately, however, the company
         maintains from year to'year fairly accurate records of  its
         chemical purchases, and it made these records  available to
         the survey team.  The table on the following page presents
         data on the average amounts of chemicals used  by the  company
         over a year, data based on both the company records and
         direct findings of the survey.

3.   An Extension of the Survey

    (a)  The Search for a Waste Source

         None of the data gathered in the survey of the industrial plants
         of the City of Hagerstown provided any explanation for  the
         occurrence of the high chemical and biochemical  oxygen  demands
         that, as revealed during the baseline studies  of the  project,
         were regularly exhibited by the wastewater flows reaching the
         Hagerstown wastewater treatment plant during the early  morning
         hours on week days.  Since it was felt by the members of  the
         project team that the wastes that created these  high  demands
         were probably being discharged in the city's sewerage system
         by a single industrial plant and since the wastes exerted
         such a significant impact on the city's treatment plant and,.
         of course, on the operational  studies of the project, which,
         at the close of the scheduled portion of the survey effort,
         were well underway, it was decided that the source of these
         wastes ought to be found to disclose the exact nature of  the
         wastes.

         The plan exercised to locate the waste source was simply  to
         track the slug discharge back up the sewer line  from  the  plant
         until the point of discharge was found.  Over several workdays,
         grab samples of the wastewaters flowing in various sewer  mains
         serving the major sections of the city were collected hourly
         over the time period of 11:00 p.m. to 7:00 a.m.  and the oxygen
                                   61

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               Table 6.  CHEMICAL AND MATERIALS USED BY THE
                         W. H. REISNER MANUFACTURING COMPANY
      Chemical
    Purpose
Amount Used
   Yearly
Plant No. 1 ("Main Plant")
Wyandotte Nu-Vat (Hot
  aqueous solution)
Wyandotte F-S
Nickel Sulfate
Nickel Chloride

Boric Acid

Zinc Cyanide
Sodium Cyanide

Sodium Hydroxide
Muriate Acid, 20° Be
Nitric Acid, 42° Be
Sulfuric Acid, 66° Be
Perchloroethylene
  (tetrachloroethylene)
Plant No. 2
Oakite #160 (Hot
  aqueous solution)
Metal Cleaning

Metal Electrocleaning
Nickel Electroplating
(Barrell plating)
Nickel Electroplating
(Barrel! plating)
Nickel Electroplating
(Barrell plating)
Zinc Electroplating
(Barrell plating)
Zinc Electroplating
(Barrell plating)
Zinc Electroplating
(Barrell plating)
Pre-plati ng.Etchi ng
Pre-plating Etching
Pre-plating Etching
Solvent (Vapor Degreaser)
Metal Cleaning
(See Note 1)

(See Note 2)
    500 Ibs

    100 Ibs

     50 Ibs

250-300 Ibs

200-250 Ibs

    150 Ibs

     80 gals
     14 gals
     14 gals
    330 gals (See
    Note 3)
    900 Ibs (See
    Note 4)
                                    62

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                           Table 6.  continued
                                                         Amount Used
      Chemical                Purpose                      Yearly
Oakite #34                Deoxidizer                         500 Ibs

Allied Iridite #14.2      Painting Pretreatment               20 Ibs


Notes:  1.  Nu-Vat, a product of Wyandotte Chemical Corporation, is a
            synthetic detergent preparation, which, reportedly con-
            tains no cyanides, chromates or cresoles.  It is used in
            hot aqueous solution, 2 to 4 ounces in one gallon of water.
            When metal cleaning is being carried out, the maximum
            amount of Nu-Vat solution that is discharged to the
            sanitary sewer per day is about 50 gallons.  All discharges
            are batch.

        2.  F-S, also a product of Wyandotte Chemical Corporation, is a
            phosphate cleaner which is mixed with water in the propor-
            tions of 6 to 10 ounces of F-S per gallon of water.

        3.  Every two months, about 4 gallons of perchloroethylene,
            which is used as the solvent in the company's metal vapor
            degreaser, are discharged to the sanitary sewerage system.

        4.  The tanks containing the Oakite #160 solutions are dumped
            only once or twice a year, depending on their use, with the
            liquid being discharged to the sanitary sewer and tank
            sludges being hauled away.
                                   63

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     demand  indices  (GDI's) of the samples determined.  In addition,
     in  order  to  confirm  that the waste slug was indeed entering the
     treatment plant on the mornings of the sewer main sampling,
     grab  samples of the  plant influent were also collected hourly
     over  the  early  morning hours and their GDI's subsequently measured.

     Prior to  the initiation of sample collection in the source search
     effort, time-of-flow measurements were made in the sewer lines to
     establish the appropriate starting time of each sewerline samples
     were  not  collected to late, i.e., after the slug of waste had
     passed  the selected  sampling points.  These measurements also
     gave  some feel  for the residence time of wastewaters in the
     different sewerline  sections examined.  They were made by in-
     jecting dye  (rhodamine B) into the sewage flow at various points
     at  the  extremes of the sewerage system and then timing how long
     it  took for  the dye  to reach the treatment plant.  The longest
     flow  time measured—1 hour and 55 minutes—occurred in the
     extensive "north line" which serves the northern section of
     the city, with  the dye injection being made at the extreme
     end of  the line, at  the Mack Truck plant.  Flow times from
     the extremes of other sewer lines—east, south and west—ran
     about an  hour or less.  Therefore, it was concluded that an
     11:00 p.m. starting  time for each sampling period was sufficiently
     early to  catch  the slug no matter where in the system samples were
     collected.

     By  this sampling technique, it was discovered that the waste
     with  the  high chemical oxygen demand was coming to the treatment
     plant through the west line.  Subsequently, intensive sampling
     of  this line was conducted over a period of a couple weeks, the
     sampling  crew moving up the line from one key manhole to the
     next.  As a  result,  the source of the potent wastes was isolated
     and found to be a cheese plant belonging to the Breakstone Sugar
     Creek Foods  Division of the Kraftco Corporation.

(b)   Breakstone Sugar Creek Foods Division, Kraftco Corporation -
     500 McDowell Avenue, Hagerstown, Maryland.

     Immediately  after the Breakstone Foods plant was discovered to
     be  the  source of the slug waste discharges of concern, it was
     included  in  industrial survey effort of the project.  As had
     been  done with  the other industries surveyed, in-plant inspec-
     tions were made of the industry by members of the project survey
     team.  Key personnel of the Breakstone Sugar Creek Food Division
     upon  learning of the inclusion of cheese plants in the survey
     cooperated fully with.the survey team and supplied the team with
     all requested plant  operating data.

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The plant, which employs 26 persons, produces cottage cheese,
sour cream and sour dressing.  In the plant, whole milk is
separated into cream and skim milk, which are then pasteurized.
The pasteurized skim milk is put in vats, a culture of lactic
acid bacteria "starter" is added to it, and the milk is incubated
until the curd is set (i.e., until a firm coagulum is formed).
The curd is then cut into small pieces and heated until the
desired amount of whey has been expelled from it and it
develops the texture sought.  The whey is then drained off and
wasted and the curd washed.  The washed curd is subsequently
pumped to blenders, which blend cream dressing into the curd.
From the blenders, the finished creamed cottage cheese is
packaged into containers of various sizes, placed into shipping
cartons and moved to refrigerated storage in preparation for
shipping.

The pasteurized cream is made into either sour cream, sour
dressing or sweet cream dressing.  These products are packaged
separately or mixed with the cottage cheese curd.

At the end of a day's operation, or earlier when convenient or
necessary, all of the plant process equipment is washed with an
alkaline cleaner and sanitized with a chlorine solution; and,
as needed, mineral deposits in the equipment are dissolved away
by the use of diluted phosphoric acid solution.  The various
chemicals employed in these operations and added to the boiler
waters (the blow-down fraction of which enters the city's sewerage
system) of the process heaters and the amounts of them consumed
per working day are given in the table on the next page.

Plant operations are shut down on Fridays and started up again
on Sundays.  Cottage cheese whey is discharged to the city's
sewage system every week day, sometime between midnight and
4:00 a.m.  The volume of whey discharged each time is about
7700 to 8000 gallons.  The spent wash waters from the curd
washing operations, which immediately follows the dumping of
the whey, are also discharged to the city's sewerage system,
the discharge time occurring between 1:30 and 6:30 a.m. and
the discharge volume being about  23,000  to  26,000 gallons.   On
Sundays, Mondays, Tuesdays, Wednesdays and Thursdays the total
volume of process water—which includes the cottage cheese
wash water, cooling and heating water, and equipment and plant
washdown water—that is used and discharged to the sewer daily
ranges from  120,000 to  140,000 gallons.   On  Fridays,  process water
consumption drops to around  80,000  gallons;  on Saturdays,  to
about  10,000 gallons.
                                65

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        Table 7.   CHEMICALS AND OTHER SUBSTANCES USED IN PROCESSES
                        OF THE BREAKSTONE FOODS PLANT
      Chemical
     Purpose
Amount Used
   Daily
Sodium Hypochlorite
  Solution (6%)
Phosphoric Acid (75%)
Liquid Detergent
Manual Cleaner
All-Metal Recirculation
  Cleaner
Hi-Alkaline Cleaner
Garrett Calahan 153
Garrett Calahan 101-CF
Garrett Adjunct SS-CAT
  (Sodium Sulfite)
Sanitizing

Millstone Remover
Cleaning
Cleaning
Cleaning

Boiler Additive
Boiler Additive
Boiler Additive
Boiler Additive
      30 gals

      55 Ibs
       3 qts
      50 Ibs
      30 Ibs

      33 Ibs
       7 Ibs
      17 Ibs
       2 Ibs
                                   66

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tc)  Pollutional Significance of Whey

     In the dairy industry, th.e disposal of cheese whey—especially
     whey resulting from the manufacture of cottage and cream cheese-
     has always been a problem.  Currently, about 22 billion pounds of
     whey are produced each year in the United States and about one
     half of this amount goes to waste.  Therefore, the Breakstone
     Foods plant in Hagerstown is not unique in its whey disposal
     practices.

     The magnitude of the load that whey places upon a sewage
     treatment plant can be of course rather large depending on
     the amount wasted since whey is very rich in readily biode-
     gradeable organic substances.  It  is estimated that one thousand
     gallons of whey discharged per day into a treatment plant imposes
     a BOD loading on that plant equal  to the domestic water loading
     generated daily by 1800 people per day.  Thus, in the case of
     Breakstone Foods plant in Hagerstown, the 8000 gallons of whey
     discharged per working day by the  plant exerts a load on the
     Hagerstown sewage treatment plant  equivalent to the load
     generated by 14400 people—or 41%  of the city's population.
     Moreover, the wasted curd wash waters of course-exert an
     additional load.  Obviously, the load resulting from the whey
     discharge is relatively large; however, its impact on the
     municipality's sewage treatment plant was heightened severely
     because the whey was not  released  at a steady rate over a
     24-hour period but batch  discharged to reach the treatment
     plant in hefty slugs.

 (d)  Recommended Remedial Action

     Upon the conclusion of the survey  of the Breakstone Foods
     plant, the project staff  advised city authorities that the
     severity of the  impact of the whey and wash-water discharges
     on  the treatment plant could be ameliorated greatly by having
     the cheese plant install  a simple  waste flow equalization tank-
     from which the waste could be bled into the city's sewerage
     system over a 24-hour period.  The city passed  this recommenda-
     tion on to the industry,  which immediately responded by taking
     steps to design  and install an appropriate flow equalization
     system.  The project staff, however, requested  that the
     Breakstone Foods delay the installation of any  equalization
     systems until the project was completed to avoid a major change
     in  project baseline conditions while the project was still in
     progress.  This  request was honored and no equalization system
     was installed until after the operational studies of the project
                                  67

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were concluded.  When an equalization system was finally con-
structed and placed into operation, an immediate and marked
improvement in the performance of the sewage treatment plant
was observed by plant personnel.
                               68

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                                SECTION VI

                  STUDIES OF VARIOUS PRETREATMENT METHODS


A.  Wastewater Analysis Schedule for Pretreatment Studies

    Shortly after the wastewater analyses of the project baseline study
    were completed and the data compiled and evaluated, a wastewater
    sampling and testing schedule was prepared for the pretreatment
    studies of project and submitted to FWQA for review and comment.
    The schedule was rather ambitious in that it included many more
    analyses than were originally considered in the project program
    plan.  Tests that were suggested by the findings of the baseline
    study and that were felt would be of value to the pretreatment
    studies were added to the original list of proposed analyses.
    The final schedule, which was designed to meet the sampling and
    testing requirements of each of the pretreatment studies, is
    presented on the following pages.  Generally, this schedule was
    fairly well adhered to over the course of the studies.

B.  Startup and Stabilization of the Project Facility

    On January 27, 1970, the entire wastewater flow received by the
    Hagerstown treatment plant was directed for the first time into
    and through the pretreatment tanks of the project facility and
    the diffused air system of the facility was put into service.
    Over the following three months—February, March and April—the
    preaeration of the raw sewage flow was continued to allow the
    pretreatment tanks of the facility to "stabilize."  Although the
    project program plan called for a one-month stabilization period,  -
    which was felt to be sufficient, the initiation of the first pair
    of pretreatment studies was delayed until certain uncompleted work
    on the facility, the previously mentioned modifications of the
    existing final settling tanks of plant Sections No. 1 and No. 2,
    and the construction of the additional settling tank for these
    plant sections were completed so that the treatment plant would be
    fully operational.  Throughout the three month period, tests were
    performed on the influent and effluents of the pretreatment tanks
    to follow the course of stabilization.  Initially, effluent dis-
    solved oxygen concentrations ranged between 7 and 8 mg 02/1;
    however, towards the end of February, these concentrations began to
    drop presumably as a result of the appearance of significant
    biological growths on the walls of the tanks.  By the middle
    of March effluent dissolved oxygen concentrations were in the
    range of 4 to 6 mg 02/1, where they remained until the facility
    aeration rates were changed in preparation for the first pre-
    treatment study task.
                                   69

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                         Table  8.  ANALYSIS SCHEDULE FOR THE OPERATIONAL STUDIES

Analysis
Ammonia & Organic
Nitrogen
Biochemical Oxygen
Demand
Chemical Oxygen
Demand

Chlorine Residual
Color
Type of Sample
24-hr
24-hr
24- hr

24-hr
Grab
24- hr
Composite
Composite
Composite

Composite
Composite
Sampling
1,
7A
1,
7A
1,
7A

2B
2B
1,
7A
2A,
, &
2A,
, &
2A,
, &

, 3B
, 3B
2A,
, &
2B,
7B
2B,
7B
2B,
7B

, &
, &
2B,
7B
Points
3A, 3B,
3A, 3B,
3A, 3B,

7B
7B
3A, 3B,
Analysis
Frequency
Every
3 Days
Every
2 Days
Every
2 Days

Daily
Every 8 hrs
Hours
Every
Thursday
or Friday
Remarks

To be done concurrently
with COD's.
To be done concurrently
with BOD's, and on both
filtered and unfiltered
aliquots of samples from
points 7A & 7B.
To be done only during
pretreatment by chlorina
tion

Dissolved Oxygen
(In Situ Measure-
ment)
1, 2A, 2B, 3A, 3B,
4A11, 4A12, 4A21,
4A22, 4B, 5A13,
5A23, 6A1, 6A2, 6B,
7A, & 7B.  Also head
and tail ends of all
wastewater tanks.
Daily, Week  DO Meter measurements
                                                                 Days
             made in situ.   DO at
             points 1, 2A and 2B will
             be measured continuously
             by automated monitoring
             system.

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                                        Table 8.   continued
     Analysis
Type of Sample
  Sampling Points
Analysis
Frequency
     Remarks
Hydrogen Sulfide        Grab
Mixed Liquor Micro-     Grab
  scopic Examination

Mixed Liquor Oxygen     Grab
  Uptake Rates

Mixed Liquor Suspended  Grab
  and Volatile Sus-
  pended Solids
Ni trate
Nitrite
Oxidation-Reduction
  Potentials
24-hr Composite
24-hr Composite
(In Situ Measure-
ment)
                    1, 2A, 2B, 3A, 3B,    Daily,  Week
                    7A & 7B               Days
                    5A and 5B


                    4A12, 4B, 5A & 5B     Once a  Week
                      Every
                      Wednesday
                    4A12, 4A22, 4B, 5A1    Every
                    5A2, & 5B             2 Days
1, 2A, 2B, 3A, 3B,
7A, & 7B

1, 2A, 2B, 3A, 3B,
7A, & 7B

1, 2A, 2B, 3A, 3B,
4A, 4B, 5A, 5B, 6A,
6B, 7A, & 7B
 Every
 3 Days
 Once a Week
Warburg respirometric
measurements.

Sampling point 8 to be
included during pre-
treatment by waste
activated sludge addi-
tion.

To be done every 2 days
on samples from points
1, 2A, 3A, and 7A during
pretreatment by NaN03
addition.

ORP's at points 1, 2A
and 2B will be measured
continuously by auto-
mated monitoring
system.

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                                          Table 8.  continued
         Analysis
                        Type of Sample
                      Sampling Points
                     Analysis
                     Frequency
                    Remarks
    PH
                        24-hr Composite
ro
Phosphate (Total)


Sulfate


"Sulfite" (Iodine
  Oxidizable Sub-
  stances)

Suspended Solids

Temperature


Volatile Organics
    Wastewater Oxygen
      Depletion Rates
24-hr Composite


24-hr Composite


24-hr Composite



24-hr Composite

(In Situ Measure-
ment)

24-hr Composite


24-hr Composite
                    1, 2A, 2B,  3A,  3B,
                    7A, & 7B
1, 2A, 2B, 3A,  3B,
7A, & 7B

1, 7A, & 7B
                                                1, 2A, 2B, 3A, 3B,
                                                7A, & 7B
                                                1, 3A, 3B, 7A & 7B

                                                Same as for DO
1, 2A, 2B, 7A, &
7B

1, 2A, 2B, 3A, 3B,
7A, & 7B
                      Daily
Every
3 Days

Once a Week
                      Every
                      8 Hours
                      Daily

                      Daily
               pH at points 1,  2A, &
               2B will  be measured
               continuously by  auto-
               mated monitoring
               system.
To be done turbidi-
metrically.

Analysis measures both
sulfide and sulfite
concentrations.
               To be done concurrently
               with DO determinations.
Every Thurs-   To be done by means of
day or Friday  gas chromatography.

Every Thurs-   To be done by means of
day or Friday  a DO meter.

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                                           Table 8.  continued
          Analysis
Type of Sample
Sampling Points
Analysis
Frequency
Remarks
co
     Digester Supernatant    Grab
       Liquor pH, Alkali-
       nity, and Volatile
       Acids

     Mixed Liquor            Grab
       Settleable Solids
                    Primary and
                    Secondary digester
                    supernatant liquor
                    lines

                    4A, 4B, 5A, & 5B
                    Once a Week
                    Daily
     Notes:

          (1)  Wastewater Monitoring System to be calibrated every Tuesday and Friday.

          (2)  Rates at which air, waste activated sludge, chlorine, ammonia, etc., are supplied to the
              pretreatment tanks to be recorded daily.

          (3)  Rates at which air is supplied and at which sludge is returned to Sections 1 and 2 and to
              Section 3 to be recorded daily.

          (4)  Wastewater flows to the entire treatment plant and*to Section 3 contact aeration tank are
              recorded continuously by existing flow meters.
          (5)  The wastewaters at sampling points 1, 2A and 2B will be sampled continuously and proportional
              to the flow by the automatic, refrigerated samplers of the project facility.

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              Table 9.  DESCRIPTION OF SAMPLING POINTS
Sampling Point                         Description

      1                Influent "Y-Wall" Channel  of Pretreatment Tanks
      2A               Effluent Channel  of Pretreatment Tank A
      2B               Effluent Channel  of Pretreatment Tank B
      3A               Effluent Channel  of Primary Settling Tanks 1  & 2
      3B               Effluent Channel  of Primary Settling Tank 3
      4A11             Bay 1  of Section 1  Sludge  Reaeration Tank
      4A21             Bay 1  of Section 2 Sludge  Reaeration Tank
      4A12             Bay 2 of Section 1  Sludge  Reaeration Tank
      4A22             Bay 2 of Section 2 Sludge  Reaeration Tank
      4B               Section 3 Sludge Reaeration Tank
      5A1              Section 1 Contact Aeration Tank
      5A2              Section 2 Contact Aeration Tank
      5B               Section 3 Contact Aeration Tank
      6A1              Effluent Channel  of Section 1  Contact Aeration
                       Tank
      6A2              Effluent Channel  of Section 2  Contact Aeration
                       Tank
      6B               Effluent Channel  of Section 3  Contact Aeration
                       Tank
      7A               Effluent Channel  of Settling Tanks  of Sections
                       1  & 2
      7B               Effluent Channel  of Section 3  Settling Tank
      8                Waste Activated Sludge Distribution Box of
                       Pretreatment Tanks
                                74

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                       -
          ->

                                                I
                                                 i
Figure 7.   Photomicrograph of the Aeration Tank Mixed  Liquors,  Showing  New  Fingerlike
           Growths of Zoogleal  Bacteria

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C.  Pretreatment by Plain Aeration and by Aeration and the Addition of
    Haste Activated Sludge

1.  General Conditions

    This operational study task was begun on 19 May 1.970.   Under this task,
    the wastewaters that passed through treatment  ystem A (previously
    referred to as Sections No. 1  and No. 2 of the undivided Hagerstown
    sewage treatment plant) were pretreated by aeration and the addition
    of waste activated sludge while the wastewaters that passed through
    treatment  ystem B (previously referred to as Section No. 3 of the
    undivided treatment plant) were pretreated by aeration alone.

    Over the period of the study,  the characteristics of the wastewaters
    that entered the treatment plant remained essentially the same as they
    were during the baseline study, particularly during May, June, and the
    first week of July, although the raw wastewaters contained significant
    amounts of dissolved oxygen, no sulfide and, surprisingly, quite fre-
    quently no sulfite.  On those  rate occasions when sulfite was detected,
    it was found at concentrations of only 1 mg/1 or less.

    On 9 July 1970, an extremely heavy rainfall occurred in the Hagerstown
    area, yielding 4.5 inches of rain from 1600 to 2300 hours.  As a
    result, incoming wastewater flows became abnormally high and remained
    that way until 20 July 1970.  Consequently, on 11 July 1970, the study
    program of the project was suspended (wastewater sampling being dis-
    continued) and was not started again until 20 July 1970.  To make up
    for the lost study time, the project effort was then extended to 24
    July 1970 and therefore spanned a period of 68 days.  Rain showers,
    however, also occurred on 20,  21 and 22 July 1970 to add to area
    flooding problems and to sustain high flows to the treatment plant
    and to hamper the pretreatment studies.

    These high "wet-weather" flows pointed up a major problem with the
    city's sanitary sewerage system:  Its tremendous susceptibility to
    storm water runoff.  From time to time throughout the life of the
    project, high wet weather flows plagued the study program.

    All through the first study period, the discharging of spent dye
    stuffs into the sanitary sewerage by the textile dyeing plants in
    the city continued as was readily evident by the regular week day
    appearance at the treatment plant of intensely colored wastewaters.
    Unfortunately, removal by the treatment plant of these colored wastes
    was not noticeably improved by either of the two pretreatment methods
    being employed.

    Also during the study period,  fluctuations in the pH of the raw
    sewage occurred from time to time with unpredictable and low
    frequency as they had during the baseline study.  The fluctuations
                                   76

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    were generally no more than ± 1 pH unit and were "smoothed  out"  by
    the time the wastewaters passed through the pretreatment tanks.
    The pH's of most of the raw sewage samples composited daily during
    the study fell in the narrow range of 7.1 to 7.35; yet,  there  were
    daily composites with pH values as low as 6.5 and as high as 8.0.

    The BODij of the composite raw sewage samples averaged about 200  mg/1
    but varied greatly from day to day and, over the study period, ranged
    from 83 to 403 mg/1.  The COD's of the composites also varied  con-
    siderably, ranging from 296 to 1502 mg/1; their average  value  for  the
    period was 650 mg/1.  The upper limit values of the BOD  and COD
    ranges were obtained on the same sample, which was considered  a  very
    typical sample in that it contained an unusual amount of particulate
    material.

2.  Pretreatment by Aeration and the Addition of Haste Activated Sludge.
    Treatment System A.

    Although it had been planned originally to supply air at a  constant
    rate to the pretreatment tank of System A to maintain in the tank
    fixed conditions with regards to both aeration and mixing and  to
    vary just the rate at which activated sludge was introduced into
    the tank, the air supply rate was in fact actually changed  over  the
    period within the limits of 2.0 to 2.5 thousand cubic feet  of  air
    per minute as a consequence of the variations in air supply rates
    that were effected in System B.  Over the study period,  the rate at
    which waste activated sludge was introduced into pretreatment  tank A
    was increased step wise from zero to levels of 9.0 x 10^, 1.5  x  105,
    and 3.0 x 105 gallons of sludge per day.  The concentration of sus-
    pended solids in the introduced waste activated sludge generally ran
    about one percent.  The maximum sludge feed rate of 3.0  x 105  gph
    employed during the last weeks of the study created, however,  a  demand
    for waste activated sludge that slightly exceeded the capability of
    the system to generate the waste material.  As a consequence of  this
    and the abnormally high stormwater flows that entered the plant
    during July, the level of suspended solids in the mixed liquors  of
    System A gradually decreased during the final weeks of the  study to
    about 0.5%.

    Although preaeration in pretreatment tank A had been effected  ever
    since the start of facility stabilization task, it was not  until just
    before the start of this study, the first of the operational study
    tasks, that the modifications that were being made in the treatment
    System A (construction of a new final clarifier and piping  changes
    in the existing final clarifiers) were completed; therefore, pre-
    aeration was continued and waste activated sludge was not added  to
    the raw wastewaters entering pretreatment tank A until the  third
    week of the study to allow time to gather some good baseline data
    on System A.  Although it had been hoped that this data would  show
    that System A operated with comparable efficiency to System B,
                                   77

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*<-**     \*&             -4-
1JI     *'*
                                   «.
                                **r-
                                 *%
                        ^^" -i;    .


  Yt4  ?^
  Jsa  -• '  >
                                                            &
                                                      •„

                                                      i   ..  a
                                                      *.   -ir'
     Figure 8.  Photomicrographs of the Aeration Tank Mixed Liquors, Taken
              during the Study of Pretreatment by Addition of Sodium
              Nitrate and Showing Unidentified Filamentous Bacteria
              among Small Zoogleal Masses with much Adsorbed Inert Solids
              and the General "Burnt-Out" Appearance of Overage Sludge
              Resulting from Excessive Recycling of Biological Solids
              in the Treatment Plant
                               78

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significant operation differences between the two systems were found
to exist; and these, disappointingly, made the application of the
baseline data earlier accrued on the secondary units of System B to
the secondary units of System A, unrealistic.  One of the major
differences noted was that in order to maintain a mixed liquor
suspended solids in the contact aeration tanks of System A at the
desired level of 2500 mg/1, the sludge reaeration tanks of system a
had to carry suspended solids at a level of about 10,000 mg/1; whereas,
in System B, the mixed liquor suspended solids in the sludge re-
aeration tanks needed to be carried at about only 6000 mg/1 to
achieve the same desired contact aeration tank mixed liquor suspended
solids level.  This difference was due to the difference in the
influent wastewater flow to return sludge pumping rate rates of the
two systems.  Moreover, it was evident that the air diffusion system
of System A (fixed air headers) could not drive as much air into the
mixed liquors of System A on a per volume basis as the air diffusion
system of System B could drive into the mixed liquors of System B.

As a consequence of these two differences, treatment System A did not
function as well as treatment System B under similar conditions.
While pretreatment by aeration alone was being carried out in both
systems, hydrosulfuric acid, H2S, was found frequently in the sludge
reaeration tanks of System A but found only very rarely in the sludge
reaeration tanks of System B.  And, frequently during this study, the
H£S concentrations were observed to build up in the sludge reaeration
tanks (to levels over 5 mg/1) then spill over and load the contact
aeration tanks of System A.  Of course, during the baseline study,
when preaeration was not practiced, H2S appeared quite regularly
and in great abundance throughout the entire plant, being found in
the wastewaters of the primary settling tanks, the sludge reaeration
and contact aeration tanks, and final settling tanks.  In this pre-
treatment study, this chemical species appeared with any regularity
in only the sludge reaeration tanks of System A.

In order to avoid sweeping the malodorous H?S gas from the sludge
reaeration tanks into the atmosphere in such quantities as to annoy
the public, chlorination of System A return sludges was practiced
intermittently, over the lifetime of the study task, at critical times
(normally from early evening to early morning, 1600 to 0200 hours)  but
not at times, it is believed, that would affect test results.  Of
course, this odor control practice did not permit the research team to
discover just how great the hydrosulfuric-acid-hydrogen-sulfide-gas
build up could become and, consequently, could heighten treatment
difficulties under each new operational condition tried.  However,
scientific curiousity withstanding, consistent H2S production in a
system intended to function aerobically is, without question, in.
itself, symptomatic of unsatisfactory system performance no matter
how far it is allowed to proceed.  So, it was felt that project
objectives were not subverted by limiting h^S production and that
the additional data that perhaps could have been gathered had
                                  79

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    chlorination  of  the  return  sludges  not been practiced would not be of
    sufficient  value to  the  project  to  risk  arousing public  ire in trying
    to  get  them.

    Some  of the data that was obtained  in the study on pretreatment by
    aeration and  addition of waste activated sludge are presented in  the
    tables  in the Appendices.   The data shows that pretreatment by air
    and waste activated  sludge  addition did  improve the performance of
    System  A but  show, in addition,  that the resulting performance was,
    generally,  irregular and rather  disappointing.  Yet, there appears
    in  the  data a trend  of  increasing improvement with increasing sludge
    addition, the average percent dally BOD  removal reaching  79% during
    the period  in which  the  sludge feed rate was at its maximum.
    Unfortunately, however,  the existence of this trend is somewhat
    obscured by the uncertainty of what effects the high hydraulic
    overloads experienced by the plant  toward the end of the  study
    had on  study  results.

3.   Pretreatment  by Plain Aeration.  Treatment System B

    The air supply rate  to  the  pretreatment  tank of System B  was varied
    over the study period from  1.0 x 103 to  3.5 x 103 cubic  feet of air
    per minute.  For a wastewater flow  of 2.5 mgd (the assumed average
    flow for the  study), this variation amounted to a variation in air
    application of 0.58  to  2.0  cubic feet of air per gallon  of wastewater.
    Initially,  it had been  planned that the  air supply rate  be increased
    in  steps every two weeks with the excess air generated by the constant
    speed positive displacement blowers being bled off through the pressure
    relief valves of the blowers themselves.  However, for certain selected
    air supply  rates, it was found that the  relief valves were not capable
    of  bleeding off the  high surpluses  of air generated.  As  a result, the
    air supply  rate was  not  constantly  increased in regular  steps over the
    entire  period of the study  but was  increased directly from the minimum
    rate tried  initially to  the maximum rate tried and then  decreased to
    an  intermediate rate which  was achieveable only after a  special air
    release valve (gate  valve)  was installed in the air main.

    Over the first two-week  period of the study, pretreatment tanks B
    received air  at the  1.0  x 103 cfm rate and the daily BOD removals
    by  the  system averaged  84%.  For those study periods that followed
    in  which higher preaeration rates were employed, the averages of
    the percent daily BOD removals were less than 84%.  Specifically^
    for those subsequent periods in  which the air supply rates used
    were  2.5 x  103 cfm and  3.5  x 103 cfm the average BOD removals were
    only  79 and 78%, respectively.   The dissolved oxygen concentration
    in  the  pretreatment  tank effluent increased with the stepped increases
    in  preaeration rate, going  from  an  aeration step period  average of
    1.1 mg/1  for  1.0 x 103  cfm  air to 5.6 mg/1 for 3.5 x 103 cfm air.
    However,  the  primary tank effluent  dissolved oxygen level did not
                                    80

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    change markedly over  the  study  in  the  changes  in the preaeration
    rate, the dissolved oxygen  level in  the  primary effluent generally
    staying below  1 mg/1.                                            J

    Because it Deemed  inexplicable  that  better treatment would be
    obtained with  only 1.0  x  103 cfm of  air  being  applied in pretreat-
    ment and not with  the greater air  applications, preaeration with
    1.0 x ID-* cfta  air  was tried again  during the final weeks of the
    study task.  This  time, the daily  BOD  removal  percentages were
    greater than before,  their  average being 93%.  The high flows
    created by the wet-weather  conditions  that prevailed during this
    latter period  clouded the analytical picture somewhat and it is
    difficult to say for  certain why this  particular improvement was
    observed.

    Although System B  showed significant improvement in effecting
    treatment with pretreatment by  aeration, the almost consistent
    appearance of  rather  low dissolved oxygen levels in and ORP values
    of the liquors of  the sludge reaeration  and contact aeration tanks
    strongly indicated that these units were at best just barely able
    to supply sufficient  oxygen to meet the  exerted oxygen demands.

    Perhaps, one of the most encouraging signs of treatment improve-
    ment in both Systems  A  and  B, which had  been noted ever since the
    pretreatment facility was brought  into service and preaeration
    was begun, was the reduction in the amount of suspended matter in
    the final plant effluent.   During  the baseline study, final  effluent
    suspended solids levels as  determined on 24-hours composite samples
    were generally above  100 mg/1 and  sometimes approached 200  mg/1.
    After the baseline study, when preaeration was practiced, effluent
    suspended solids levels fell well  below 100 mg/1— particularly in
    System B.

    These data as  well as the data mentioned earlier and other  pertinent
    analytical results that were gotten during the study task are also
    tabulated in the Appendices of this report.

4.  Improvements in Plant Biota

    In general, it was noteable that, as a result of both pretreatment
    methods employed,  there were improvements in the quality of the
    wastewaters being  introduced into the mixed liquor basin and in
    the performance of the basins themselves.  These improvements
    appeared despite the heavy hydraulic overloads caused by the heavy
    rains in the Hagerstown area.  It was particularly striking that
    the sulfur precipitating bacteria that had been present during the
    baseline study were absent during this study from the various
    aeration tank mixed liquors and from the water of the preaeration
    tanks,  and that new finger! ike growths of zoogleal  bacteria were
    common  in the mixed liquors.  (See Figure 7.).
    these findings represented a distinct improvement over the conditions
    prevailing in the treatment plant before pretvedtment tids applied.

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D.   Pretreatment by Addition of Sodium Nitrate and'by-Addition of Ammonia

1.   General Conditions

    During the approximately eight-week period of this study,  as a result
    of little rainfall in the Hagerstown area, the treatment plant did
    not experience the high hydraulic overloads that it had during the
    latter part of the preceding study.  Daily total flows recorded at
    the plant varied from 4.1 to 6.8 million gallons.  Thus, daily flows
    stayed well under the 7.5 mgd design average hydraulic load capacity
    of the plant.  The average flow for the period was only 5.35 million
    gallons daily.

    Sulfite, which had been associated with the discharge into the city's
    sewerage system of spent liquors from the dye-stripping operations of
    the textile dyeing plants located in the city, was rarely detected in
    the raw wastewaters although the consistent appearance at the treat-
    ment plant of intensely colored waters affirmed that the dyeing plants
    continued to operate and to discharge dyeing wastes throughout the
    study.  And, with the exception of only a few cases in which readings
    of 0.1 and 0.2 mg ^S/l were obtained, hydrogen sulfide concentrations
    in the raw wastewaters- were generally zero.  In addition,  the dis-
    solved oxygen levels in these waters were found to be lower than they
    had been throughout the preceding study assumably, as a consequence,
    of reduced stormwater inflow and infiltration during this  study.
    Over the study period, the raw sewage dissolved oxygen concentrations
    ranged from 0.3 to 1.6 mg 02/1 with an average for the period of
    0.68 mg 02/1.

    The pollutional strengths of the raw wastewaters as determined on
    24-hour composite samples ranged from 63 to 528 mg BODs/l  and 338
    to 1886 mg COD/1 with the averages for the two sets of measurements
    being 262 mg BOD5/1 and 1040 mg COD/1.  The lowest BODs and COD
    values and the highest BOD5 and COD values were obtained,  as might
    be expected, on the same samples.

    A number of unusually high pollutional strength raw wastewater
    samples were obtained at different intervals during the study but
    their high pollutional strengths were the result of materials
    introduced into the raw wastewaters by the treatment plant itself.
    The filamentous sulfur bacteria that were discovered in the plant
    during the baseline study and that subsequently disappeared from
    the plant during the first pretreatment study remained absent from
    from the plant during this study.  However, early in this  study, a
    new and different type of filamentous microorganism appeared
    throughout the plant.  This organism was of the kind sometimes
    noted in "overaerated" or underloaded extended aeration activated
    sludge systems.  Photomicrographs of the Hagerstown sewage treatment
    plant mixed liquors containing these organisms are presented in
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Figure 8 on the next page.  The bacterial filaments are sheathed
with a very sticky, watery stuff to which small zoogleal masses
readily adhere; and, thus, they form biological mats that settle
poorly and are easily buoyed by microscopic bubbles or adsorbed
oils.  Consequently, these filamentous growths that developed in
the plant created a biological sludge that would not settle well
in either the aeration basins or, when wasted, in the anaerobic
digesters.  As a result, waste activated sludge eventually would
be returned to the head of the treatment plant via the digesters
with the drawn-off digester "supernatant liquor," increasing the
pollutional strengths and the suspended solids levels of the raw
wastewater samples.

By 11 September 1970, this undesirable recycling of biological
solids caused such a buildup of suspended solids in plant and
generated such a heavy organic load on the plant that treatment
System A, which was having difficulty providing sufficient air to
its aeration basins even under "normal" loadings, began to produce
in its aeration basins and to release from there to the atmosphere
considerable amounts of hydrogen sulfide gas and the sludge in the
final clarifier of treatment System B began to bulk severely.  The
odor problem became intolerable on 17 September 1970 and around-
the-clock chlorination of System A return sludges had to be executed
to abate the intense pungent odor of H^S that was being produced and
creating much public annoyance.  On 21 September, the suspended solids
level in the daily composite raw sewage samples was over 1300 mg/1.
On 22 September 1970, in order to stop the constant cycling and
buildup of biological solids in the treatment plant, the uncovered
digester tank of the plant was placed into service to receive and
store the heavily suspended solids laden digester supernatant
liquors.  Although it was hoped that, in the open tank, the sus-
pended matter could be made to settle out by chemical means, through
addition of ammonia gas to raise the pH of the held liquors to above
8.5, effective solids separation was never achieved.  However, the
use of the tank to store the digester liquors temporarily broke the
sludge recycling cycle and relieved the plant of its self-generated
overload.

As a result, this difficulty with suspended solids recycling in the
plant did not become troublesome again until two to three weeks later;
and, at that time, it was compounded by the occurrence of rising sludge
(believed to be caused by denitrification) in the primary settling
tanks of System A.  Furthermore, at the end of the study period, with
relatively high concentrations of digester solids again coming into
the plant proper, a gas was noticed evolving from the primary tanks
of both Systems A and B.  A sample of this gas was collected and
analyzed in the laboratory by means of gas chromatography and found
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    to be a mixture of methane (62.5%),  nitrogen  (37.0%),  and  oxygen
    (0.5%).  This  information thus  indicated  that a  sizeable amount
    of methane-forming bacteria has been swept  from  the  digesters  and
    deposited in the primary tanks.  Fortunately, during the two-week
    "change-over period" that followed the  termination of  the  pretreat-
    ment study the solids problem abated and  the  treatment system
    gradually returned to its baseline conditions.

2.   A Search for the Cause of the Appearance  of the  Filamentous
    Organism

    Because the filamentous bacteria that produced the poorly  settling
    sludges had been seen before by members of  the project team  in only
    "overaerated"  or underloaded extended aeration sewage  treatment
    plants, it was felt that (1) they may be  saprophytes of the  mixed
    liquor zoogleal bacteria—that  is, that they  may utilize for substrate
    the walls zoogleal masses and other  generally refractory materials of
    lysed zoogleal cells—and thus  become populous in underloaded  systems
    or (2) they may be a direct consequence of  nitrate additions to the
    wastewaters (or the relatively  high  nitrate concentrations produced
    in extended aeration treatment  systems  exceeding having long aeration
    periods).    A laboratory experiment involving aeration for  several
    days of an unfed sample of the  Hagerstown treatment  plant mixed liquors
    containing the filamentous bacteria  and no  nitrate was carried out
    under the direction of the project biologist  in  order  to test  the
    first hypothesis, i.e., to see  if the filamentous organism would
    proliferate under truly extended aeration conditions.   They  did not,
    and so it was  concluded that they were  indeed not saprophytes  of the
    zoogleal bacteria.  No effort unfortunately was  ever made  by members
    of the project team to rigorously test  the  second hypothesis although
    it was hoped that such a test could  have  been made before  the  project
    was terminated.

3.   Pretreatment by Addition of Sodium Nitrate

    Under this operation study of the project program, sodium  nitrate
    (Chilean nitrate, 16% nitrate nitrogen) was added to the raw waste-
    waters that were directed through treatment System A of the  divided
    treatment plant.  The initial rate of addition was 250 Ibs of  sodium
    nitrate per day, and this rate  was subsequently  doubled every  two
    weeks over the eight-week period of  the study.   Thus,  sodium nitrate
    feed rates of 250, 500, 1000, and 2000  Ibs/day were  employed.  For a
    wastewater flow of 5 mgd--the flow that had been anticipated for the
    treatment system—these feed rates would  have yielded  nitrate-nitrogen
    concentrations in the wastewater flow of  roughly 1,  2, 4 and 4 mg/1,
    respectively.   However, over the study  period, System  A flows  ranged
    from 1.9 to 4.1 mgd and averaged 2.9 mgd; therefore, nitrate-nitrogen
    concentrations that were introduced  into  the  wastewaters were  on the
    average 1.7 times greater than  planned.
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The sodium nitrate was added to the wastewaters at the head end of
the pretreatment tank of System A and this tank was aerated with air
supply rates being maintained at about 1400 ± 300 cfm over the study
period to promote mixing as well as to keep parti oil ate matter in
suspension.  The sodium nitrate was fed to the wastewaters in solu-
tion form by the dry chemical feed machine of the project facility
except when the feed rate was 2000 Ibs/day.  This feed rate exceeded
the feed rate capacity of the feed machine; and, consequently, the
output of the feed machine had to be supplemented by manually adding
sodium nitrate to the wastewaters in order to achieve the desired
feed rate.

As expressed in terms of BOD5 removal, the degree of treatment
obtained in the treatment system did not increase consistently with
increasing nitrate feed rates, although the highest average percentage
BODs removal, which was 85%, for any two-week period of the study was
realized for that two-week period in which the sodium nitrate feed
rate was at its maximum, 2000 Ibs/day.  Yet, because of the high
levels of suspended solids that were in the system at this time and
which added more to the COD than to the BOD values of the wastewaters,
the average percent BOD removal for the same period was only 51%,
which is far lower than the average percent COD removal for any
preceding two-week period.  On the other hand, however, the daily
percent removals of suspended solids over the entire study period
were of course much higher than previously experienced with the
overall average for the period being 91%.

Within a week after the sodium nitrate feed rate was increased to
2000 Ibs/day, during a period when considerable quantities of
activated sludge were being wasted into the pretreatment tank of
System A in hopes of alleviating the previously mentioned problem
of high suspended solids levels in the treatment plant, sludge
began rising in the primary tanks of System A—but not in the primary
tanks of System B.  Consequently, on 8 October 1970, the nitrate feed
rate was reduced for two days to 8 Ibs/day, and the formation in the
primary tanks of a sludge-scum blanket subsided.  The. nitrate feed
rate was then increased to 2000 Ibs/day again, and again a thick
(6-inches deep) sludge-scum layer formed on the surface of the
wastewaters in the primary tanks of System A, evidently as a result
of denitrification.

Only during that time when sodium nitrate was being added to the
wastewaters at the maximum rate employed where appreciable nitrate-
nitrogen concentrations detected in the effluent from the pretreatment
tank.  At the lower feed rates, nitrate-nitrogen concentrations in the
pretreatment tank effluent were generally below 0.2 mg/1.  Since the
nitrate nitrogen that disappeared in the pretreatment tank did not re-
appear in the system as either ammonia, organic, or nitrite nitrogen
to any significant extent, it is believed that the reduction in
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    nitrate concentrations  in the system was  a result of the biological
    utilization of nitrate  as a hydrogen acceptor ("chemical  oxygen
    source")  rather than as a nitrogen source, with  the concomitant
    loss of nitrogen as  ^

    The more significant experimental  data obtained  in this  pretreat-
    ment method study can be found tabulated  in the  appendices  of this
    report.

4.  Pretreatment by Addition of Ammonia

    In this study, ammonia  was added to the raw wastewaters  that were
    passed through treatment System B  of the  divided treatment  plant,
    with the point of ammonia introduction being at  the head end of the
    pretreatment tank of System B.  Initially, anhydrous ammonia from
    manifolded 150-lb cylinders was fed by means of  the ammoniator of
    the project facility in ageous solution form; however,  after several
    weeks of study time  had elapsed, direct feeding  of gaseous  ammonia
    into the wastewaters had to be resorted to because the  hydraulic
    ejector assembly of  the ammoniator became so severely clogged by
    heavy scaling that ammonia feed rates above 60 Ibs/day  could not
    be attained.  Direct feed was accomplished by temporarily modifying
    the ammoniator in a  manner that enabled the machine to  still  regulate
    and measure gas flows,  while ammonia was  being withdrawn under pressure
    instead of under a partial vacuum.

    The initial ammonia  feed rate used was 30 Ibs of ammonia per day.
    For the wastewater flow that had been anticipated for the treatment
    system—VIZ., 3 mgd—this feed rate would have increased the ammonia-
    nitrogen concentration  in the wastewaters (which, incidentally ran
    about 15 ± 5 mg NH3-N/1) by only slightly more than 1 mg/1.   Ammonia
    feed rates were doubled every two  weeks at the same time the nitrate
    feed rates were doubled in the concurrent pretreatment  study; thus,
    ammonia feed rates of 30, 60, 120  and 240 Ibs/day were  utilized in
    the study.  To insure accuracy of  gas flow measurements, the rotameter
    of the ammoniator was checked frequently  by directly weighing the
    ammonia cylinders to determine their losses in weight in a  given
    period of time, usually 24 hours.

    Air was also introduced into the pretreatment tank of System B, the
    introduction of course  being made  through air diffusion  system of  the
    tank.  As in the case of pretreatment by  nitrate addition,  aeration
    was carried out to keep particulate matter in suspension and to mix
    the wastewaters with the ammonia feed.  Air supply rates to the pre-
    treatment tank were  maintained at  2000 ±  500 cfm over the lifetime
    of the study.
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    Although it had been anticipated from the wastewater flow  data  that
    was  obtained during the preceding study task that System B wastewater
    flows  would be about 3 mgd during this study, wastewater flows  in
    System B were actually less than that value for the study, ranging
    from 2.1 to 2.9 mgd with a study average of 2.4 mgd.  Even though
    these flows were less than anticipated, they all exceeded  the
    design average hydraulic load capacity of the secondary units of
    System B of 2.0 mgd.  Yet, the treatment system generally  effected
    fair to good treatment over the study period.

    The  average percent removals of BOD5 realized for each of  the four
    different ammonia feed rate periods were:  90% (30 Ibs NHo/day),
    89%  (60 Ibs NH3/day), 80% (120 Ibs NH3/day), and 95% (240  Ibs NH3/
    day) while the percent COD removals for these same periods were:
    89%  (30 Ibs NH3/day), 88% (60 Ibs NH3/day), 78% (240 Ibs NH3/day).
    Moreover, over the entire study, the daily percent suspended solids
    removals were usually in the 90's to give an overall average removal
    of 95% for the study period.

    All  these figures indicate improvement in treatment in System B over
    the  treatment that was realized during both the baseline and preceding
    pretreatment studies.  However, the effect of the'lower wastewater
    flows and, particularly, the solids problem experienced in this study
    on the removal percentages was indeed significant and even may have
    obscured the full treatment benefits that^may be deriveable from
    ammonia addition.

    Additional data obtained in this study are listed in tables that may
    be found at the end of this report.

E.   Pretreatment by Addition of Potassium Permanganate and by  Addition
    of Chlorine

1.   General Conditions

    This study, like the immediately preceding treatability study, was
    conducted over a period of about eight weeks.  Specifically, the study
    was  initiated on October 30, 1970, and concluded on December 26, 1970.
    Dry weather conditions prevailed for nearly the entire time and,
    except for the final four days of the study period, influent flows
    ranged from 4.6 to 8.2 mgd and averaged 6.4 mgd, which is  below the
    7.5  mgd average design flow for the plant.  During the last four days
    of the study, high rains swelled the waste flows from 9.8  to 19.7 mgd.

    The BODc's of daily composite samples of the raw sewage ranged  from  a
    low of 82 to a high of 372 mg/1 and averaged 186 mg/1 while the COD's
    of these same samples varied from 307 to 1334 mg/1 and averaged 671  mg/1
    These BOD and COD averages are less by about one third than the
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    corresponding  BOD  and  COD  averages of the  first operational  study.
    In  addition, plant influent  suspended solids  concentrations, which
    were  also measured on  the  24-hour composite samples of  the  raw
    sewage,  ran from 40 to 800 mg/1  and  averaged  only  350 mg/1.  Thus,
    the average values for BOD,  COD  and  suspended solids concentrations
    over  the period apparently show  that, as far  as these parameters  are
    concerned, the quality of  the  raw sewage had  returned essentially to
    baseline characteristics during  this study; yet, however, over  the
    first week of  the  study period,  the  concentration  of suspended  solids
    in  the raw sewage  and, concomitantly, the  COD of the raw sewage were
    consistently higher than the respective averages for the study  period
    evidently as a' result  of the system  having not yet fully returned to
    baseline conditions from the unusual solids problem created  in  the
    preceding study.

    As  in all the  preceding studies, the highly colored wastes  from the
    textile dyeing plants  constantly entered the  treatment  plant on week
    days  throughout the study  period.  And, during the first 3  to 4 weeks
    of  the study period, the level of sulfite  and raw  sewage usually
    stayed at around 1 mg/1 although it  did drop  to a  low of 0 mg/1 and
    rose  to a high of  2 mg/1.  But,  over the remaining 4 to 5 weeks of
    the study, even though wasted  dyestuffs continued  to enter  the  plant
    as  before, no  sulfite  was  ever found in the raw sewage.  Moreover,
    throughout the entire  8-week study period, no suflide was ever  detected
    in  the plant influent  or in  any  part of the treatment system.   In
    addition, only on  one  day  out  of the entire eight  weeks of  the  study
    was there no dissolved oxygen  found  in the raw sewage;  otherwise, raw
    sewage dissolved oxygen concentrations fell in the range of  0.3 to
    4.8 mg/1 with  1.7  mg/1 being the mean dissolved oxygen  concentration
    value of the raw sewage for  the  study period.

F.   Pretreatment by Addition of  Potassium Permanganate

    By  means of the dry chemical feed machine  that had been employed  in
    the previous study for feeding sodium nitrate, potassium permanganate
    was added to the wastewaters being channeled  into  pretreatment  tank A.
    The chemical was applied as  an aqueous solution at rates of 20, 40, 80
    and 160 Ibs/day with each  rate being tried in the  sequence  given  for a
    two-week period.   Except for the last four days of the  study, daily
    waste flows through treatment  System A remained fairly  constant,
    staying within 4.5 ± 1.1 mgd.  Based on the 4.5 mgd flow, potassium
    permanganate doseage rates were  then 0.53, 1.1, 2.1, and 4.2 mg/1,
    respectively,  for  the  four feed  rates utilized.  Pretreatment tank A
    was aerated with about 2000  cfm  of air to  insure good mixing of the
    chemical with  the  wastewater.
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    Best  treatment of the wastewater by treatment System A in  terms  of
    the average percent COD removal  for a particular two-week  doseage
    period  was  achieved during the first two-week period when  the
    permanganate feed rate was just 20 Ibs/day.   The average percent
    BOD removal  for the system during the two-week period was  83%.
    However,  in terms of percent BOD5 removal, treatment during  the
    first two-week period by the system was  erratic and no better than
    the two subsequent two-week doseage periods  with the average percent
    BOD5  removals for all three periods being about 75%.  The  average
    percent BOD removals for the second and  third two-week doseage
    periods (when feed rates were 40 and 60  Ibs/day, respectively)
    were  65 and 66%, respectively.  Treatment deteriorated significantly
    in the system during the final two-week  period, owing to the greatly
    increased wastewater flows and resulting relatively high solids
    carry over in the final effluent of the  system.  The averages of
    the daily percent BODs and COD removals  for the final period were
    only  69% and 62%, respectively.  For this same period, suspended
    solids removals averaged only 54%.  In fact, the average percent
    suspended solids removals for the various doseage periods  consistently
    decreased from the first period to the last with the percent removals
    for  the first, second and third periods  being, respectively, 86%, 82%
    and  71%.

    Although the highest average percentage  COD removal for any  two-week
    period during the study occurred during  the first two-week period when
    permanganate was being added at a rate of 20 Ibs/day, it seems from
    the  experimental data that this improvement was more apparent than
    real, resulting from mainly high influent COD's caused by  a  typically
    high  influent suspended solids levels rather than as a direct effect
    of permanganate addition.  6005 removals, which would not  be as
    greatly effected by high suspended solids levels in the plant influent,
    were  not necessarily better for this two-week period than  for any other
    of the study nor, in fact, was the quality of the final effluent of
     treatment System A.  Therefore, it appears reasonable to conclude that
     the  potassium permanganate additions produced no measureable improve-
    ment  in the performance of the treatment system.

2.   Pretreatment by Chiorination

    While the wastewaters coursing through treatment System A  were being
     pretreated by addition of potassium permanganate, the wastewaters in
    System B were being pretreated by chlorination.  As with the sodium
     nitrate additions, one chlorine doseage rate was tried for a single
     two-week period, then doubled the next second week period  and so on
    over  the four two-week periods of the eight-week study. Chlorine was
     initially applied at 150 Ibs/day, then increased to 300, to  600  and
     finally to 1200 Ibs/day.  Wastewater flows in System B for the first
     31 days of the study averaged 1.45 mgd and ranged between  1.0 and
     1.8 mgd.   For the final 25 days of the study—except for the very
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     last  4  days when  flows  rose  and  varied  between 3.2  and  5.0 mgd  in
     System  B  due  to the  contribution of  the previously  mentioned storm-
     water runoff  flows—wastewater flows  increased suddenly,  averaging
     2.4 mgd and ranging  from  2.2 to  2.7 mgd.   In  any event, by calculation,
     the chlorine  doseages for the various feed rates and  the  average flow
     values  were approximately 12, 24,  30  and 60 mg/1, respectively.

     As in the parallel study  of  pretreatment by addition  of potassium
     permanganate, the best  treatment obtained in  terms  of COD removal
     by prechlorination of the raw sewage was  realized during  the first
     two-week  period of the  study during which time the  chlorine feed
     rate  was  150  Ibs/day; the average  percent COD removal for the entire
     two weeks was 90%.   But,  unlike  the  situation that  developed in the
     permanganate  study,  percent  BOD5 removals achieved  by System B  for
     the period were also high and consistently so, their  average being
     93% and their value  range, 89% to  98%.   Moreover, except  for one day
     when  the  percent  suspended solids  removal  obtained  was  unusually low,
     73%,  the  daily percent  suspended solids removals too  were high.
     They  averaged 97% exclusive  of the 73%  removal value  and  the average
     of the suspended  solids concentrations  in daily composites of the
     final effluent were  just  4 mg/1.

     Over  the  three succeeding two-week study periods, the individual
     period averages of the  daily percent  removals of all  three wastewater
     parameters--BOD5, COD,  and suspended solids—consistently decreased
     from  one  two-week period  to  the  next.   This trend can be  seen in the
     table of  percent  removal  values  given below.

       TABLE 10.   AVERAGE PERCENT REMOVALS OF BOD5, COD  AND SUSPENDED
                   SOLIDS ACHIEVED FOR  THE FOUR TWO-WEEK PERIODS OF
                      THE STUDY OF PRETREATMENT BY CHLORINATION
                                                    Removals
Pretreatment       Chlorine  Feed  Rate
   Period             (Ibs/day)
                                        %BOD        %COD         %SS
1
2
3
4
150
300
600
1200
93
84
73
69
90
71
65
61
97
90
76
74
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     Shortly after the chlorine feed rate was increased to 600 Ibs/day
     to initiate the third two-week study period, chlorine residuals  of
     the order of 0.5 to 1.5 mg/1 were frequently detected in grab samples
     of the effluent of the primary tank (i.e., influent of the contact
     aeration tank) of System B.  When the feed rate was subsequently
     increased to 1200 Ibs/day, chlorine residuals in grab samples of the
     primary effluent were regularly detected and ranged as high as 1.5 to
     5.0 mg/1; furthermore, chlorine residuals were detected for the  first
     time, although in trace amounts, in the effluent from the aeration
     basin.  General experience has shown that, while even very high
     doseages of chlorine applied directly to the liquors of aeration tanks
     for rather short periods of time may exhibit no appreciable effect on
     the performance of the tanks, the continuous maintenance over an ex-
     tended period of time of even relatively low chlorine residuals  in a
     mixed liquor basin can adversely effect the performance of the basin.
     Consequently, it is believed that the frequent to almost constant
     appearance of chlorine residuals in the influent of the aeration tank
     of System B during the last 4 weeks of the study contributed to  the
     decrease in the degree of treatment achieved by the system.   During
     the last 4 weeks of the study and particularly the last two, bleaching
     of suspended matter in the wastewater flow was readily apparent  and
     the odor of chlorine readily detectable throughout the treatment system.

6.   Pretreatment by the Select Method

     As mentioned earlier, the final operational study task of the project
     involved the application of the pretreatment process revealed by the
     preceding studies to be the most effective in treating the wastewaters
     to all the incoming raw sewage and required the recommendation and
     utilization of the entire sewage treatment plant.  Thus, upon the
     completion of the final pair of pretreatment studies, data obtained
     from all six studies was reviewed; and it was concluded that pre-
     chlorination carried out at the rate of 150 Ibs of chlorine per  day
     per 2 mgd of flow had yielded the best treatment results and that this
     doseage, the lowest tried, was probably more than sufficient since the
     degree of treatment that was realized had actually dropped off with the
     higher chlorine doseages employed.  Moreover, one important question
     remained to be answered:  How significantly had the dry-weather  flow
     conditions that existed at the time prechlorination was investigated
     at the 150 Ibs/day feed rate enhanced the goodness of treatment?
     Consequently, prechlorination was selected at the pretreatment method
     to be applied to the entire incoming raw sewage flow of the Hagerstown
     treatment plant.

     The high flows that occurred during that last week of the final  pair of
     pretreatment studies lasted through the month of December and into
     January.  Although the "change over", i.e., recombination of treatment
     systems A and B, was effected quickly by simpled valve changes,  pre-
     chlorination of the entire plant influent was not begun until
     January 18, 1971, in hopes the high incoming flows would subside.
     Unfortunately, they did not; but, nonetheless the final study was


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begun on January 18th since the project program had already fallen
considerably behind schedule by that time.

Chlorine was applied to the waste flow at a selected rate of 300
Ibs/day for the entire duration of the study, which was 68 days.
Except for nine days in early February when flows ran between 5.9
and 7.4 mgd, all daily flows exceeded the design hydraulic loading
of the treatment plant.  The average of the daily flows for the
68-day period was 9.0 mgd.  Thus, the applied chlorine doseage
based on this average flow value amounted to only 4 mg/1.

The constantly high wastewater flows through the aeration and final
settling tanks of the treatment plant swept biological active solid
from these tanks and out of the treatment plant.  Consequently, the
maintenance in the contact aeration tanks of reasonable biomass was
difficult; in fact, contact aeration tank mixed liquor suspended
solids levels dropped to 600 mg/1 and even lower on several occasions
during the study period.  As a result, treatment suffered appreciably.
For fourteen days scattered throughout the study period, final effluent
suspended solids level exceeded influent suspended solid levels; and
the daily percent suspended solids removals for the remaining 54 days
of the study averaged only 57%.  However, for these 54 days, the
average concentration of suspended solids in the final effluent was
55 mg/1, which, although high, was not as high the value obtained
during the baseline studies.  The daily percent BOD5 and COD removals
were very poor, their averages for the period being 63% to 53%, re-
spectively, and they varied widely from one day to the next as can
be seen from the data presented in the appendices.

During the last week in January filamentous organisms appeared in
moderate numbers in the mixed liquor of only the aeration tanks of
old system B and they persisted for no longer than two to three
weeks.  They were identified as being to the genus Sphaerotilus and
were definitely not the same filamentous organism that was prevalent
in the plant during the baseline studies nor during ammonia and
nitrate addition studies.  In any event, they apparently diminished
the settleability of the biological floe since floe particles were
swept readily from the plant by the high wastewater flows.  In
general, however, the biomasses in all the various aeration basins
of the treatment plant appeared to be highly stabilized, containing
many stalked ciliates of the Vovtiaella microstomas species and young
zoogleal masses of bacteria.

Needless to say, the results of the study were extremely disappointing,
but they served to emphasize the city's great need to minimize the
inflow of stormwaters into the sanitary sewerage system.
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H.   Sludge Dewatering Experiments

     As part of the final operational study task of the project program,
     the ease with which digested sludges and undigested waste activated
     sludges that were produced in the treatment plant during the testing
     of the select pretreatment method could be dewatered was to be in-
     vestigated.  Thus, prior to the start of the final study task an
     empty plant digester, Digester No. 4, was readied for service; and,
     shortly after the study was begun, when it was felt that "steady-
     state" conditions in the treatment had been established, the prepared
     digester was placed into operation, receiving and digesting sludges
     in accordance with usual plant practices.  The digester was brought
     relatively rapidly into operation by means of the conventional pro-
     cedure for reactivating a "stuck digester" (2), although some delay
     was experienced due to the Inability of the digester heating system
     (which had fallen in a state of disrepair) to adequately maintain
     proper digester temperature, 95 ± 3°F.  The sludges introduced into
     the digester were a combination of primary and waste activated sludges
     withdrawn from the primary settling tanks of the treatment plant.

     One of the sludge dewatering studies undertaken was of the ease with
     which sludges from Digester No. 4 and undigested waste activated
     sludges from the aeration basins of the treatment pTant could be
     dewatered on a vacuum filter; and, a second study was of the ease
     with which just Digester No. 4 sludges could be dewatered on sand
     beds.  The vacuum filter utilized in the first study was a Komline-
     Sanderson 3' x V pilot "Coilfilter" with 10 square feet of filter
     area made of stainless-steel coil springs.

     The sludges dewatered on this vacuum filter were first conditioned
     with chemicals; namely, ferric chloride, lime, and/or a commercial
     polymer preparation known as Floculate #532, manufactured by the
     DuBois Chemical Co.  Conditioning varied from treatment with ferric
     chloride (10% solution) and lime (10% solution) to treatment with a
     mixture of polymer, ferric chloride and lime.  Preliminary laboratory
     tests on the sludges determined the chemical requirements which pro-
     duced the best filter cake for the types of sludges to be filtered.

     The results of the vacuum filtration experiments showed that the
     digested waste activated sludges, on the whole, had a slightly lower
     moisture content, 73 ± 8%, than the undigested or raw wastes activated
     sludges tested, 76 ± 6%, when preconditioned with ferric chloride and
     lime.  Little improvement in moisture reduction was realized when a
     polymer was included in the preconditioning process, 71 ± 4% for the
     undigested sludges and 71 ± 5% for the digested sludges tested.
     However, these moisture contents are within the range of typical
     sludge filter cake—70% to 80% by weight.  The water content in these
     dewatered sludges lend them satisfactory for short distance hauling
     to a landfill for final disposal.
                                    93

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An important measure of the efficiency of the filtration process is
of course the filtrate quality.  The clarity of the filtrate is an
indirect measure of the efficiency of solids recovery, since these
solids which are not recovered in the sludge cake are discharged to
the filtrate stream.  In the experiments performed under this
investigation the percentage of solids remaining in the filtrate
ranged from 1 to 3% for digested sludges treated with FeCl^ and
lime to 2 to 21% for raw sludge treated with the same chemicals.
Addition of the polymer compound (Floculate 532) in pretreatment
of the sludges seems to have improved the filtrate quality of the
raw sludges seems to have improved the filtrate quality of the raw
sludge filtrates; however, the limited amount of data available for
this experiment casts doubt on the certainty of this conclusion.

Overall, the digested sludges exhibited slightly better qualities
of the two types of sludges tested by vacuum filtration, as is
generally true.

As mentioned, also tested under the sludge dewatering task was the
dewatering of digested sludges on a sand bed.  Three separate beds
were set up; one containing a 4-inch deep layer of sludge; another,
an 8-inch deep layer of sludge; and yet another, a 10-inch deep
layer of sludge.  The results of this investigation showed that
dewatering of the digested sludge to a moisture content comparable
to that for the same type of sludge dewatered on a vacuum filter
required 4 to 5 days for the 4-inch thick sludge layer, 7 to 8 days
for the 8-inch thick sludge layer, and about 10 days for the 10-inch
thick sludge layer.
                                 94

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Table 11.  THE DECREASE WITH TIME IN THE PERCENT MOISTURE
              CONTENT OF DIGESTED SLUDGE PLACED ON SAND
              DRYING BEDS IN VARIOUS LAYER THICKNESSES

Date
4/15/71
4/17/71
4/19/71
4/20/71
4/21/71
4/22/71
4/23/71
4/26/71
4/27/71
% Moisture Content
4"
78.2
77.4
70.3
67.6
—
—
—
—
—
for Various Thicknesses
8"
81.1
83.8
78.8
78.0
76.5
74.1
64.8
67.6
—
of Sludge Layers
10"
82.6
82.5
79.0
78.4
75.4
75.6
62.2
70.2
70.7
                           95

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                                  SECTION VII

                                    SUMMARY
A.  General
    Much effort, well  beyond the scope of the original  project plan was
    expended to define as accurately as possible the causes and to
    develop practical  solutions to the problems faced by the City of
    Hagerstown in the treatment of its combined domestic-industrial
    wastewaters.  The original analytical schedule of the project program
    plan was expanded, additional survey tasks undertaken, and operational
    studies extended to obtain more complete information and to insure the
    achievement of project objectives.

    As a result of the project, it was clearly shown that the municipal
    treatment plant suffered from severe hydraulic overloading during
    wet-weather conditions and organic overloading from periodic slug
    discharges of cottage cheese whey from a local cheese manufacturing
    plant.  It was revealed too that the aeration system of the plant
    could not supply sufficient air to the aeration tanks of treatment
    System A, the older of the two sections of the treatment plant, to
    meet exerted oxygen demands.  It was demonstrated that the plant
    was not being adversely affected by toxic materials or even inhibi-
    tory substances in the wastewaters as had been hypothesized unless,
    of course, the effects of any toxic materials were masked during the
    project by the overwhelming impact on the plant of the hydraulic and
    organic overloads and the inadequacy of the aeration system of treat-
    ment System A.  Moreover, it was learned that a filamentous sulfur
    organism existed in great numbers among the biota of the plant prior
    to the execution of the project pretreatment studies and created a
    poorly settling activated sludge and that this organism could be
    destroyed through aeration of the raw wastewaters and the settling
    characteristics of the activated sludge of plant thereby improved.
    In addition, it was shown that preaeration eliminated H2S formation
    in the primary tanks, keeping the raw wastewaters "sweet," and
    minimized it in the aeration basins under slug organic loading
    conditions and that, under high flow conditions, pretreatment by
    plain aeration, by aeration with addition of waste activated sludge,
    and by chlorination was well as perhaps by ammonia addition improved
    plant performance.  Finally, the project indicated that pretreatment
    by sodium nitrate addition may lead to the occurrence of appreciable
    denitrification in the primary tanks, causing there a rising sludge
    problem and to the appearance in the biomass of a witherto unidentified
    filamentous bacterium that can markedly increase the bulkiness of the
    biologically active sludge.
                                    96

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    In summary, the project, through the application of Us pretreatment
    schemes, significantly improved the performance of the treatment plant
    under dry-weather conditions by:  (1) markedly reducing H2S production,
    (2) allowing higher mixed liquor suspended solids levels to be carried
    without the fear of frequent odor formation, (3) decreasing the bulki-
    ness of the biological floe and consequently the concentration of
    suspended solids in the final plant effluent, and (4)  increasing
    considerably BODs and COD removals.  Furthermore, the  project resulted
    in the development of specific recommendations affecting the operation
    of the treatment plant.  These recommendations were: (1) stormwater
    inflows into the city's sanitary sewerage system should be reduced
    appreciably, (2) the performance of the air diffusion  systems of the
    aeration tanks of treatment System A of the sewage treatment plant
    should be improved, (3) the performance of the anaerobic digesters
    of the plant should be upgraded, (4) a sound treatment plant preventive
    maintenance program should be established and implemented, and (5)  the
    batch discharge into the sanitary sewerage system of high pollutional
    strength and otherwise noxious materials by industries should be pro-
    hibited.  A further project recommendation was that industries currently
    practicing batch waste discharging should be strongly  encouraged to
    install waste flow equalization tanks.

B.  Subsequent Work

    Shortly after the final operational study of the research project was
    concluded, the city undertook the carrying out of the  above-mentioned
    recommended actions.  The aeration tanks of System A were dewatered
    one at a time to discover why it was so difficult to drive air into
    these tanks.  It was discovered that almost half of the carborundum
    air diffusers in the system had been removed, (probably at one time
    or another because they had become clogged or broken)  and the air
    header plugged.  The city, subsequently, replaced all  the missing
    as well as the remaining carborundum diffuser elements in both Systems
    A and B with new "sock" type fine bubble diffuser elements and supple-
    mented the air supply of System A with surplus air from the pretreatment
    facility.  In addition, the city requested Breakstone  Foods to proceed
    with its planned installation of a waste flow equalization tank at  the
    company's Hagerstown cheese plant, a request with which the industry
    quickly complied.  Moreover, the city continued and expanded further
    the industrial waste survey begun under the project, requesting
    improvements in the waste disposal practices of other  industrial
    plants, and undertook an ambitious program to abate stormwater inflow
    and infiltration in its sewer lines, and continued the pretreatment
    of the incoming wastewaters using aeration with waste  activated sludge
    addition.
                                     97

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As a direct result of the changes made in the aeration systems  of the
plant, the application of the pretreatment method of preaeration with
waste activated sludge addition, and the installation by Breakstone
Foods of a flow equalization tank, plant performance improved remark-
ably (3).  For October and November 1971, the monthly averages  of
daily percent BOD5 removals were 92% and 94%, respectively.   However,
plant performance dropped off during the months of January and
February 1972, evidently as a result of the reoccurrence of high
wet-weather flows.  But, the plant still achieved 87% and 88% BOD5
removals for these months, respectively.  Thus, it is anticipated
that when stormwater flows in the sewerage system are substantially
reduced, the treatment plant should be able to achieve consistently
a fairly high degree of wastewater treatment.
                                 98

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                               SECTION VIII

                                REFERENCES
1.    Wrigley, I.E., "Hagerstown, Maryland, Water Pollution  Control
      Plant," Unpublished report presented to the Hagerstown City
      Council, Hagerstown, Md. (January 1967).

2.    "Anaerobic Sludge Digestion," Manual of Practice No. 16,
      Water Pollution Control Federation, Washington, D.C. (1968).

3.    Barnhart, E., Private communication, Hagerstown, Md.
      (May 1972).
                                99

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                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
1. REPORT NO.
  EPA-600/2-78-0^3a
                                                           3. RECIPIENT'S ACCESSIOI*NO.
 ». TITLE AND SUBTITLE.
  Pretreatment of the Combined Industrial-Domestic
 Wastewaters of Hagerstown,  Maryland - Volume I
             5. REPORT DATE
               March 1978 issuing date
             6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
                                                           8. PERFORMING ORGANIZATION REPORT NO,
  David S. Kappe
9. PERFORMING ORGANIZATION NAME AND ADDRESS

  Scientific Research Division
  Kappe Associates, Inc.
  Hagerstown, Maryland   21740
             10. PROGRAM ELEMENT NO.
                   1BB610
             11. CONTRACT/GRANT NO.
                   11060 EJD
 12. SPONSORING AGENCY. NAME AND ADDRESS
  Robert S. Kerr Environmental  Research Laboratory
  Office of Research and  Development
  U.S.  Environmental Protection Agency
  Ada,  Oklahoma  74820
             13. TYPE OF REPORT AND PERIOD COVERED
                   Final  Draft
             14. SPONSORING AGENCY CODE
                 EPA/600/15
 15,SUPPI FMFMTARY NOTES
  Appendices to Volume  I  can be found in Volume  II  (EPA-600/2-78-043b), and can  be
  obtained through  NTIS.
 1&.ABSTRACT
 The sewage treatment plant of  the  city of Hagerstown, Maryland—a  manufacturing city
 with about  130 industrial firms,  which are classified in more  than  25 different
 product categories—receives for treatment domestic sewage and  a diversity of indus-
 trial  waste and process waters.  Some of these industrial wastewaters  exert high
 immediate and ultimate oxygen  demands that could not be satisfied  by the treatment
 plant  or were otherwise detrimental  to the biological treatment processes of the
 treatment system.   Therefore,  certain methods of "pretreating"  the city's combined
 wastewaters to render these waters more amenable to treatment by the existing treat-
 ment plant were tried and evaluated.   The pretreatment methods  tested  were intended
 to  assist the plant in meeting the oxygen demands by providing  initial  oxidation.
 The methods were:   diffuse aeration  with and without the addition  of waste activated
 sludge, chlorination, addition of  sodium nitrate, and the addition of  potassium
 permanganate.   Ammoniation was also  tried in an effort to destroy  some of the more
 noxious industrial materials in the  wastewaters.   Both aeration and  chlorination
 proved  to be effective methods of  pretreatment, with the efficacy  of aeration being
 enhanced somewhat  by the addition  of waste activated sludges.   Both  methods increased
 the BODc removal  efficiency of the plant under dry-weather conditions  from less than
 70% to  Better than 90%.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTIFIERS/OPEN ENDED TERMS
                          c.  COSATI Field/Group
  Sludge
  *Sewage  Treatment
  Hagerstown, Maryland
  Combined Industrial/
     Municipal
 *Joint Treatment*
 *Pretreatment*
             50 B
 8. DISTRIBUTION STATEMENT

 Release to Public
19. SECURITY CLASS (ThisReport)
  Unclassified
            21. NO. OF PAGES

               116
 0. SECURITY.Cl/iSS
  UnclassTfTed
(This page)
                                                                         22. PRICE
EPA Form 2220-1 (9-73)
                                            100
                                                          •U.S. GOVERNMENT PRINTING OFFICE .  1978 0-720-335/6075

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