EPA-600/2-76-082
  MARCH 1976
Environmental Protection Technology Series
Do not remove. This document
should be retained in the EPA
Region 5 Library Collection.
                           TERTIARY TREATMENT FOR
                           f HOSPHOROS REMOVAL AT
                        ELY, MINNESOTA AWT PLANT
                    APRIL, 1973 THRU MARCH, 1974

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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 five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:

     1.    Environmental Health Effects Research
     2.    Environmental Protection Technology
     3.    Ecological Research
     4.    Environmental Monitoring
     5.    Socioeconomic Environmental Studies

This report  has  been  assigned  to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate  instrumentation, equipment, and  methodology to repair or prevent
environmental 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-600/2-76-082
                                                                  March  1976
Yl
 '                          TERTIARY TREATMENT FOR PHOSPHORUS REMOVAL
XJ                                   AT ELY,  MINNESOTA AWT PLANT
                                  April,  1973 thru March, 1974
d
f
J                                               by
3,
                                         John W.  Sheehy
                                      Francis L.  Evans,  III
                                  Wastewater Research  Division
                           Municipal Environmental  Research  Laboratory
                                     Cincinnati,  Ohio   45268
                                       Grant No. S-802309
                                         Project Officer

                                         Robert M. Brice
                                  Shagawa Lake Research Project
                                Environmental Research Laboratory
                                    Corvallis, Oregon  97330
                                                          U.S. Environmental Protection Agency
                                                          Region 5, Library (PL-12J)
                                                          77 West Jackson Boulevar.d, 12th Floor
                                                          Chicago,  !L  60604-3590

                             U.S. ENVIRONMENTAL PROTECTION AGENCY
                              OFFICE OF  RESEARCH AND DEVELOPMENT
                          MUNICIPAL ENVIRONMENTAL RESEARCH LABORATORY
                                    CINCINNATI,  OHIO  45268

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                                 DISCLAIMER

This report has been reviewed by the Municipal Environmental Research Labora-
tory, U.S. Environmental Protection Agency, and approved for publication.
Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
                                      11

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                                    FOREWORD


 The  Environmental  Protection Agency was  created because of  increasing public
 and  government  concern  about the  dangers  of pollution to the health and welfare
 of the American people;  Noxious  air,  foul water, and spoiled  land are tragic
 testimony  to  the deterioration of our  natural environment.  The complexity of
 that  environment and the interplay  between its components require a concen-
 trated and integrated attack on the problem.

 Research and  development is that  necessary first step in problem solution and
 it involves defining the problem, measuring its impact, and searching for
 solutions.  The Municipal Environmental Research Laboratory develops new and
 improved technology and systems for the prevention, treatment, and management
 of wastewater and  solid and hazardous waste pollutant discharges from municipal
 and community sources, for the preservation and treatment of public drinking
 water supplies, and to minimize the adverse economic, social, health, and
 aesthetic  effects  of pollution.  This publication is one of the products of
 that research; a most vital communications link between the researcher and
 the user community.

This report shows that an effectively operated advanced wastewater treatment
 facility can reliably and continuously reduce total phosphorus to a very low
concentration and in this way enhance the quality of the receiving body of
water.
                                 Louis W. Lefke
                                 Acting Director
                                 Municipal Environmental Research Laboratory
                                    111

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                                   ABSTRACT
This report documents the first 12 months of continuous operation of the 1,5
mgd Ely tertiary wastewater treatment plant which reliably removed 99% of the
influent total phosphorus and discharged an extremely low effluent total
phosphorus concentration, averaging 0.045 mg/1,   The tertiary treatment
facility, consisting of flow equalization two-stage lime clarification, dual-
media filtration and chlorination, was designed to reduce total phosphorus
concentration in the existing trickling filter plant effluent to 0.05 mg/1.
Operational costs for the tertiary plant averaged $0.24/m3 ($0,91/1000 gallons)
However, it is estimated that the facility could have been operated to achieve
an effluent phosphorus concentration of 1 mg/1 for approximately $0.13/m3
($0.50/1000 gallons),

This report includes performance data, operational data, maintenance require-
ments, and operating costs for the Ely AWT facility from April, 1973 through
March, 1974.  The report presents a thorough discussion of phosphorus per-
formance data along with pertinent information on suspended solids, turbidity,
TOG, calcium and iron removal.  The report also includes a discussion of
sludge treatment processes including data such as sludge volumes, vacuum
filter yields, and sludge dryness.  Operating data described includes waste-
water flow, chemical dose, pH, clarifier solids volume and gravity filter
head loss.  The report further describes routine maintenance and manpower
requirements, including major equipment breakdowns and repairs.  Operating
costs are divided into five categories and 27 sub-categories.  The five cost
categories are personnel, chemicals, utilities, laboratory and miscellaneous
supplies, and equipment operation and repair.
                                        IV

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                                  CONTENTS

                                                                         Page
 Foreword                                                                 m
 Abstract                                                                 •
 List of Figures                                                          vii
 List of Tables
                                                                          -LyC
 Acknowledgements
                                                                          JC
 Sections
 I       Summary  and Conclusions                                            1
 II      Recommendations                                                    4
 III     Introduction                                                       5
 IV      Process  Description                                                10
       A.  Primary and Secondary Facilities
       B.  Tertiary Treatment Unit Processes
       C.  Appurtenant Equipment
       D.  Analytical Program and Sample Scheduling
V      Process Performance                                               iq
       A.  Secondary Plant
       B.  Tertiary Plant
           1.  Two-Stage  Lime Clarification
           2.  Dual-Media Filtration
       C,   Summary of Tertiary Plant  Performance:  Plant  Reliability
           and Effluent Variability

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                                                                     Page





VI     Sludge Treatment and Disposal                                  47




       A.  Sludge Handling




       B.  Sludge Thickener Influent Characteristics




       C.  Tertiary Thickener Performance




       D.  Vacuum Filtration and Landfill Disposal




VII    Operation and Maintenance                                      56




       A.  Personnel Organization and Tasks




       B.  Plant and Equipment Problems




       C.  Maintenance Requirements




VIII   Costs of Operation and Maintenance                             65




IX     References                                                     69




X      Appendices




       A.  Treatment Plant Layout Plans and Design Criteria           70




       B.  Schematics of Liquid and Sludge Flows                      82




       C.  Secondary Plant Data                                       89




       D.  Tertiary Plant Data Summary: April, 1973 thru March, 1974  92




       E.  Total Phosphorus Data: April, 1973 thru March, 1974       102




       F.  Distribution of Operation and Maintenance Costs           116
                                    VI

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                                    FIGURES

 No.                                                                     Page

 3-1     Shagawa Lake  Restoration  Project  Site                            7

 4-1     Flow Diagram  of Ely Secondary Wastewater Treatment  Plant         11

 4-2     Flow Diagram  of Ely Tertiary Wastewater Treatment Plant          13

 5-1     Monthly Average Values of Influent Alkalinity, Lime Dose,
        Clarifier pH, and Effluent Total  Phosphorus for First-Stage
        Lime Clarifier                                                   20

 5-2     Influence of Upper  Mix Zone  Solids  Volume on Total Phosphorus
        Removal  in First-Stage Lime  Clarifier                            22

 5-3     Monthly  Average  Values of Upper Mix Zone Solids Volume, Percent
        Total P  Removal, and Total P Concentration in Second-Stage Lime
        Clarifier Effluent                                               23

 5-4     Influence of Iron Dose on Total Phosphorus Removal in Second-
        Stage Lime Clarifier                                             26

 5-5     Influence of Tertiary Plant Flow on Total Phosphorus Removal
        by First and Second-Stage  Effluent                               28

 5-6     Monthly Average Suspended Solids in First-Stage Influent,
        First-Stage Effluent, and Second-Stage Effluent                  30

 5-7     Monthly Average Concentrations of Suspended Solids,  Turbidity,
        Particulate Phosphorus and Total Phosphorus in Second-Stage
        Clarifier Effluent                                               32

 5-8     Effect of Hydraulic Loading on Total  Phosphorus Removal by
       Dual-Media Filtration                                            37

 5-9    Variability of Total Phosphorus  in Second-Stage Clarifier
       Effluent and Filter Effluent  April 1,  1973  to  March  31, 1974     42

5-10   Variability of Turbidity in Second-Stage  Clarifier Effluent and
       Filter Effluent, April 1,  1973  to  March 31,  1974                  43

5-11    Variability of Suspended Solids  in Second-Stage Clarifier
       Effluent and  Filter  Effluent, April 1,  1973  to March 31,  1974   44
                                   VII

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N£.                                                                      Pag<

5-12   Monthly Values of Coefficient of Variation for Total  Phos-
       phorus Removal by Each Tertiary Unit Process  and by Tertiary
       Treatment System                                                   45

6-1    Monthly Averages of Feed Solids Concentration, Filter Yield,
       and Drum Speed for Vacuum Filtration of Lime  Conditioned
       Combined Biological-Chemical Sludge                                54
                                   Vlll

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                                   TABLES

No.                                                                    Page

4-1    Analytical Sampling and Analysis Schedule                         18

5-1    Total TOC Removal by Tertiary Lime Clarification                  33

5-2    Particulate and Soluble Phosphorus Removal by
       Dual-Media Filtration                                             36

5-3    Gravity Filter Performance                                        38

5-4    Total Phosphorus Removal Summary -
       April, 1973 thru March, 1974                                      41

6-1    Biological and Chemical Sludge Flows to Tertiary
       Sludge Thickener                                                  48

6-2    Chemical Sludge Characteristics                                   50

6-3    Tertiary Sludge Thickener Overflow Characteristics                52

6-4    Vacuum Filtration of Combined Biological and Chemical
       Sludges                                                           53

7-1    Manpower Requirements for Ely AWT Plant                           62

8-1    Operation and Maintenance Costs for Ely Wastewater Treatment
       Plant - April, 1973 thru March, 1974                              66

8-2    Unit Costs of Chemicals and Power for Ely AWT Plant
       Operation                                                         67
                                     IX

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                               ACKNOWLEDGEMENTS


The construction and operation of the Ely AWT Plant was supported by the U.S.
Environmental Protection Agency's Office of Research and Development for the
City of Ely, Minnesota under the administration of the Honorable J. P. Grahek,
Mayor.

The overall planning and execution was urider the general direction of Mr.
Robert M. Brice, EPA Project Officer for the Shagawa Lake Research Project.

The operation of the Ely AWT plant depended on the efforts of numerous indi-
viduals.  Thanks are extended to these and especially to Glen Lindroos, City
of Ely, for providing much of the background data on the operation and main-
tenance of the existing trickling filter plant and to Robert Randall, EPA, for
supervising the chemistry laboratory where myriad analytical determininations
were required.  Particular thanks are extended to the twelve EPA operating
personnel who in no small way contributed to the successful performance of
the Ely AWT plant.

Appreciation is also expressed to Dr. R. L.  Bunch, Messrs.  Richard Brenner,
J. M.  Smith and James J.  Westrick of the Municipal Environmental Research
Center in Cincinnati Ohio, who provided program guidance and assistance in
the conduct of this study.

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                                   SECTION I

                            SUMMARY AND CONCLUSIONS


1.   The costs required to operate the Ely Wastewater Treatment Plant from
April 1, 1973 through March 31, 1974 were $389,107.64.  During this period
1.6 x 106m3 (427.7 million gallons) of wastewater were treated at a cost of
$0.24/m3 ($0.91/1000 gallons).


2.  For the one-year period of operation from April 1, 1973 to March 31,
1974 the tertiary facilities at the Ely AWT plant performed as follows:
Parameter
(mg/1)
BOD
TOC
Suspended Solids
Turb.-JTU
Soluble P
Particulate P
Total P
2-Stage Lime
INF

46
Clarification Dual-Media Filtration
EFF* %


70**
23
2.
1.
4.

68
88
56**

18
7.
2.
0.
0.
0,


1
0
033
050
083
Removal INF*

61
90
91
99
97
98

19.
8.
2.
0.
0.
0.

5
7
22
038
051
089
EFF % Removal
12.
17.
1.
0.
0.
0.
0.
3
9
3
56
037
008
045
.
8
85
75
3
84
49
Removal in
Tert. Pit
_
61%
98%
98%
98.6%
99.6%
99.0%
 *  The difference between the clarifier effluent values and the filter influ-
ent values was due to the chemical reactions resulting from sulfuric acid and
ferric chloride additions which were made between the sampling points in the
second-stage  clarifier overflow and the dual-media  filters' splitter box.

**  The tertiary plant influent values were greater than the secondary plant
effluent values due to high solids and phosphorus in the waste flows which
were returned to the head of the tertiary plant.
 3.   Tertiary plant recycle streams  returned to the head of the high-rate
 trickling filter secondary treatment facilities most likely improved the
 performance of the secondary treatment facilities.   For the one-year period
 of operation from April  1, 1973 to  March 31,  1974 the secondary treatment
 facilities achieved the  following performance.

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BOD
Suspended Solids
Total Phosphorus
Influent
(mg/1)
90
202
7.07
Effluent
(mg/1)
39
44
3.81
                                                                Reduction
                                                                    57
                                                                    78
                                                                    46
 4.  The 208 m3 (55,000 gallon)  wet well of the tertiary influent pump station
 was used as an equalization tank.   In addition to secondary effluent  flow to
 the influent tank consisted of six sample waste streams and clarifier over-
 flows.   The tertiary influent tank,  together with the manually operated pump
 controller, served to dampen hydraulic variations.   Steady flows could be
 maintained for periods of time  varying from one to eight hours,  resulting in
 improved tertiary plant operation.

 5:  The first-stage lime clarifier removed an average of 93.5  percent of the
 total  influent phosphorus in 12 months of continuous  operation   The monthly
 median  clarifier  pH values varied  from 11.84 to 12.07.   The  performance of the
 first-stage clarifier was related  to  the  solids inventory carried in the mix-
 ing zone which in turn was determined by  the speed  of the turbine mixer.

 6.   The second-stage lime clarifier operated at a pH  of 9.6  +_  0.1 and removed
 an  average  of 72.2  percent of the  second-stage  influent  total  phosphorus.
 Through two-stage clarification, total phosphorus removal  averaged 98 percent.
 The addition of 3-6 mg/1  iron (as  Fe   ) to  the  second-stage  clarifier quali-
 tatively improved coagulation/flocculation  and  enhanced  the  removal  of phos-
 phorus .

 7.   The  removal of  soluble phosphorus,  particulate phosphorus, and total phos-
 phorus  through  dual-media  gravity  filtration  averaged 3 percent,  84 percent
 and 49 percent, respectively.  The mean filter  effluent  suspended  solids was
 less than 2  mg/1, and  the  mean effluent turbidity averaged 0.6 JTU.   The
 adjustment of the filter  influent pH  to 7-8 prevented, deposition  of  CaCO,  on
 the  filter and  the  addition of 2-4 mg/1 iron  (as Fe+3) minimized  the  disso-
 lution of particulate phosphorus.  Filter runs up to  24 hours and hydraulic
 loadings up  to  8.6  m/hr  (3.5  gpm/sq ft) were achieved.

8.  Sludge solids loading  to  the gravity thickener averaged 2780 kg/day  (6130
 Ibs/d^y) of  combined biological-chemical sludge at an average daily flow of
 109 m /day  (28,760  gpd).  Of the total flow 12 percent was undigested combined
raw and secondary sludge from the trickling filter plant at 7-10 percent solidsj
 62  percent was  first-stage lime clarifier underflow at 0.8-1.0 percent  solids;
and 26 percent was second-stage lime clarifier underflow at 2.1 percent solids.'
Thickener underflow solids concentration averaged 15 percent.  Sludge handling
problems encountered were(a) high solids in the thickener overflow which was
due to poor settling characteristics of the undigested combined raw and
secondary sludges and (b) odors caused by processing undigested sludge from
the secondary plant.

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9.  Prior to vacuum filtration, thickener underflow was conditioned with lime
at the average rate of 33 gm/kg (66 Ibs/ton)  of dry solids.  At an average
loading of 47.0 kg/nr/hr (9.6 Ibs dry solids/sq ft/hr)  the filter cake con-
tained greater than 30 percent solids 95 percent of the time, and averaged
35.7 percent solids for a ten month period.   Conditioning sludge with lime
increased the filter yield by 81 percent from an average of 27.0 kg/m2/hr
(5.6 Ibs/sq ft/hr) to an average of 49.0 kg/m2/hr (10.0 Ibs/sq ft/hr).

10. Operation of the secondary and tertiary facilities  at the 5678 m /day
(1.5 mgd) Ely AWT plant required an operating staff of  15-16 persons plus 3-4
laboratory personnel.  Four shifts of two men each operated the tertiary
facilities.  While the vacuum filter was in operation,  the full-time attention
of one operator was required.  In addition to routine maintenance, consider-
able time and money were expended for corrective maintenance of the comminutor,
secondary bioligical clarifier, second-stage lime clarifier, sludge thickener,
and sludge underflow pumps.  Additional time was spent  to improve safety
conditions within the plant buildings and around the grounds,

Based on the operation of the 5678 m /day (1.5 mgd) Ely AWT plant, it is esti-
mated that operation of a similarly designed 37,850 m^/day (10 mgd) plant
would require an operating staff of 18 to 20 persons plus 3-4 laboratory
personnel.

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                                  SECTION II

                                RECOMMENDATIONS


1.  Long term operation of the two-stage lime clarifier indicated that per-
formance of the process with respect to clarifier effluent phosphorus and
suspended solids concentrations was related to effluent turbidities.  Auto-
matic turbidity measurements with continuous read-out is suggested for both
first and second-stage lime clarification process monitoring,

2.  Performance of the sludge thickener was adversely affected in direct pro-
portion to the amount of undigested combined raw and secondary sludge in the
thickener.  Poor settling characteristics of this sludge increased solids in
the thickener overflow and decreased underflow solids concentration.  The
short-term use of a polymeric flocculant aid improved thickener performance
and is suggested for continuous use,

3.  Prior to plant start-up, safety training for supervisors and operating
personnel should be provided because of the potential hazards which are
associated with complex treatment equipment and chemical us.age.

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                                 SECTION III

                                INTRODUCTION


The Shagawa Lake Restoration Project in Ely, Minnesota is a field activity of
the Eutrophication and Lake Restoration Branch of EPA's Environmental Research
Laboratory, Corvallis, Oregon.  The Project is being carried out in coopera-
tion with the Wastewater Research Division of EPA's Municipal Environmental
Research Center in Cincinnati Ohio which has assumed primary responsibility
for operation of the tertiary wastewater treatment plant.  The objective of
the project is the demonstration of the feasibility of improving the quality
of a culturally eutrophic lake by removing phosphorus from the Ely municipal
wastewater treatment plant effluent, the primary source of nutrient supply to
that lake.

Eutrophication is the process whereby a body of water is enriched with aquatic
plant nutrients to concentrations which result in nuisance levels of biological
activity.  During early stages of evolution, lakes are typically low in bio-
logical productivity and high in purity.  As lakes age, biological productivity
increases first through levels that are optimal for the propagation of desir-
able game fish but eventually levels are reached which result in a lowering of
water quality to the point that a lake no longer provides adaauate habitat for
desired species.  In the final stages of evolution, they often undergo periods
of low oxygen content, may possess undesirable tastes and odors, and develop
recurring nuisance algal blooms.  Lakes thus may lose their aesthetic proper-
ties, may become unacceptable as a source of water supply, and may become
relatively useless for fishing, boating or swimming.

Natural eutrophication is generally a slow process requiring hundreds or thou-
sands of years for objectionable water characteristics to develop.  Cultural
eutrophication, however, which is due to man's activities, proceeds much more
rapidly.  A major cause of cultural eutrophication is the discharge of muni-
cipal wastes to a body of water.  Such discharges greatly increase the flow of
nutrients to the body of water drastically accelerating the eutrophication
process.

Cultural eutrophication is a major environmental problem.  The concern of sci-
entists and demands for remedial action have prompted investigations of tech-
niques to reduce the productivity of culturally eutrophic lakes and to restore
them to higher purity.  Pilot or full-scale demonstrations have shown that
diversion of wastewater effluent around a lake, in situ chemical treatment of a
lake to precipitate nutrients, and dredging and aeration may be useful lake
restoration techniques.  Another technique, nutrient removal from wastewater
entering a lake, appeared technically feasible.  However, prior to initiation
of the Shagawa Lake Project, its effectiveness had not been demonstrated.

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 Ely, Minnesota, which has a population of 5,000 persons,  is located in north-
 eastern Minnesota,  about 160 km (100 miles)  north of Duluth.   Shagawa Lake,
 shown in Figure 3-1,  is located adjacent to  the City of Ely.   It was formed,
 along with many other lakes in the region, during the retreat of the Wisconsin
 Glacier approximately 10,000 years ago.   The lake has a surface area about 970
 hectares (2397 acres), a maximum depth of 14 meters  (46 ft)  and an average
 depth of about 6 meters (20 ft).   Burntside  River, which  flows out of oligo-
 trophic Burntside Lake, is the major contributory, entering Shagawa Lake from
 the west.   Several  smaller tributaries flow  into the lake on  the southwest and
 the north.   The only  outlet is the Shagawa River on  the eastern side of the
 lake.

 There are  few natural sources of algal growth-promoting nutrients, and the
 high productivity of  Shagawa Lake has been attributed to  the  nutrients in the
 municipal  wastewater  which has been discharging into the  lake since prior to
 1900.   The City employed primary wastewater  treatment until  1954 when a high-
 rate trickling filter and secondary settling facilities were  installed.   Dur-
 ing the period when secondary treatment  plant effluent was  being discharged
 to  the lake,  studies  have shown that about 80 percent of  the  phosphorus enter-
 ing the lake  through  surface flows came  from this  source.   About one percent
 of  the surface flow has been attributed  to municipal wastewater and about 75
 percent to  Burntside  River.

 A number of factors influenced the selection of Shagawa Lake  as the site for
 demonstrating the restoration of  a eutrophic lake by phosphorus removal  from
 a wastewater  treatment  plant  effluent.   (1)   Shagawa Lake has  had  a history of
 nuisance algal blooms.   (2)   The  lake water  quality  is of particular concern
 because its outflow passes  through parts  of  the Superior National  Forest,  a
 National Wilderness Area (Boundary Waters Canoe Area)  and Canada.   (3)   The
 eutrophic state of  the  lake was uncommon  among the lakes in the area.   (4) The
 major  surface flow  of water  into  Shagawa  Lake  is high purity water and  the
 calculated  hydraulic  retention time in the lake is very short  - about nine
 months.  (5)   Municipal  wastewater was the major source of nutrients  to  the
 lake,  there being no  significant  agriculture  or industrial activity in  the
 area.

 The Shagawa Lake  Restoration  Project  was  initiated on a pilot  plant  scale in
 Ely, Minnesota in 1966.  A  106 HP/day (28,000  gpd) tertiary wastewater  treat-
 ment plant  processed  effluent  from the Ely municipal  secondary (high-rate
 trickling filter) wastewater  treatment plant.   Using  isolated  test  basins
 floating in the  lake, the tertiary effluent was  evaluated relative  to algal
 growth  potential.   Concurrently,  a limnological  investigation  was  carried out
 to document the  trophic  state  of  the  lake and  to provide characterization for
 comparison  of "before"  and "after"  quality.  Results  of the study have been
 published  (1).

The tertiary wastewater treatment pilot plant included chemical clarification,
multi-media filtration, carbon adsorption, and ion exchange.   In these early
 studies, both  lime and alum clarification followed by settling and filtration
reduced the total residual phosphorus concentration to less than 0.05 mg/1.
Carbon adsorption and ion exchange were not necessary in achieving the low
residual phosphorus concentrations.

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                                    SHAGAWA LAKE
           BURNTSIDE
             RIVER
970 Hectares
(2397  Acres)
WASTEWATER
 TREATMENT PLANT
                                             STINKY !__w
  SHAGAWA LAKE
ST. LOUIS COUNTY,
   MINNESOTA
                                                            -T
                                                            '
                                                                KILOMETERS
                                                               0  0.5  1.0
                                                       SCALE
                  FIGURE 3-1.  SHAGAWA  LAKE RESTORATION PROJECT SITE.

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 The use of floating basins as "receiving ponds" for the tertiary effluent
 isolated segments of the lake and permitted evaluation of the pilot plant
 effluent in a simulated lake environment.  The basin tests demonstrated that
 the tertiary treatment system substantially reduced the potential of the efflu-
 ent to produce algal blooms when mixed with Shagawa Lake water or Burntside
 River water.

 Based upon the positive results of these pilot studies,  the Environmental
 Protection Agency considered a demonstration study for a tertiary wastewater
 treatment system in order that full-scale restoration of Shagawa Lake could be
 studied.   The rate and extent of recovery of the  lake would be documented and
 limnological  studies would continue for several years.   Background data de-
 scribing  biological,  physical,  and  chemical  characteristics  of the  lake  had
 already been  developed.   These data would be used  in determining the  validity
 of several mathematical  models to be developed in  an attempt to describe the
 eutrophication process,  and to simulate the  lake water quality improvement
 expected  to result from  tertiary phosphorus  removal  from secondary effluent.

 In 1971,  a Research and  Development  grant was awarded by the EPA to the  City
 of Ely, Minnesota to design a tertiary wastewater  treatment  facility.  The
 primary objectives of this  grant were  the following:

 1.  To  develop a  complete  set  of engineering plans and specifications  for a
 tertiary  wastewater treatment  system to remove phosphorus  from secondary efflu-
 ent to  a  residual  of 0.05 mg/1  of total phosphorus or less.

 2.  To build  into  the  design  of the  phosphorus removal facilities the  capabil-
 ity for upgrading  the  effluent  quality  to meet the State of Minnesota  BOD and
 suspended  solids  standards.  The  standards proposed by the State  for Ely's
 effluent discharge, which would  guide  the design of the proposed  facilities,
 were 25 mg/1  BOD5  and  30 mg/1  suspended solids.

 3.  To develop  sound engineering  estimates for construction and operating
 costs for  the proposed facilities.  The construction cost estimates were to be
 sufficiently detailed  so that the cost of the phosphorus removal facilities
 could be considered apart from the cost of repairs to the existing plant.
 Likewise,  operating costs were to be estimated separately for both the second-
 ary trickling filter plant and the tertiary phosphorus removal facility.

 The City of Ely engaged the architectural-engineering firm of Toltz, King,
 Duvall, Anderson and Associates,  Inc., St. Paul, Minnesota, to carry out the
 design objectives.  Plans and specifications for the AWT plant were completed
 in June of 1971.

 In this same year funds for construction and operation of the tertiary waste-
water treatment facility and for renovation of the existing high-rate trick-
 ling filter plant  were provided  by two  EPA grants totalling  $2,572,358.

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The six primary objectives of the construction-operation grant are listed
below:

1.  Construct tertiary wastewater treatment facilities which would remove phos-
phorus from the effluent of the typical high-rate trickling filter plant at
Ely, to a residual of 0.05 mg/1 of total phosphorus or less.

2.  Demonstrate that the effluent from the upgraded facility could meet an
effluent BOD standard of 25 mg/1 and a suspended solids standard of 30 mg/1
as proposed by the State of Minnesota.

3.  Begin construction of tertiary wastewater treatment facilities not later
than September I, 1971, and complete construction and have facilities ready
for "start'up" and "shake-down" by May 31, 1972.

4.  Repair and restore the existing conventional wastewater treatment facili-
ties at Ely by July 31, 1972.

5.  Provide facilities to return to the headworks of the existing conventional
treatment facilities for subsequent treatment, the maximum practicable amount
of runoff which drains into a channel known as "Stinky Ditch" from adjacent
hillsides and which for many years flowed untreated into Shagawa Lake.

6.  Operate the combined wastewater treatment complex to a high degree of
efficiency with maximum practicable removal of phosphorus, BOD, and suspended
solids for a continuous period of three years commencing on or around August 1,
1972, while concurrent limnological studies are conducted on Shagawa Lake.

Completion of construction was delayed until December 1972 because of adverse
weather and labor strikes.  Debugging and shakedown took about three months
and the tertiary facility was put into operation on April 1, 1973.

Because of the unpredicted delays in completion of construction and start-up,
the grant period was subsequently extended to January 31, 1976.

Although this construction-operation grant provided for construction, utility
costs, chemicals, fuel, supplies, etc., it did not provide funds for operating
personnel.   Therefore,  the Wastewater Research Division of the Municipal
Environmental Research Center, Cincinnati provided funding for an engineer-
superintendent, twelve plant operators, and four laboratory technicians.
The laboratory technicians are part of an analytical laboratory staff that
does all analytical work including that required for operation, for evaluation
of the plant, and for the limnological studies.

All other project personnel, laboratory supplies, administrative services, and
incidental costs not provided under the grant, or from MERL-Cincinnati were
provided by the Environmental Research Center in Corvallis, Oregon.

-------
                                   SECTION IV

                               PROCESS DESCRIPTION
 A.   Primary and Secondary Facilities

 The 5678 m3/day (1.5 mgd) high-rate trickling filter plant consists of a grit
 chamber, trash rack, primary clarifier,  trickling filter,  secondary clarifier,
 chlorine contact chamber, and a high-rate anaerobic sludge digester.   The sec-
 ondary plant is shown schematically in Figure 4-1 and the  design criteria are
 given in Table A-l.

 The grit chamber is  10 m (32.5 ft)  long  x 1  m (3  ft)  wide  x 1.2  m (4  ft)  deep.
 It  is equipped with  a proportional  weir  which maintains  a  constant  flow rate
 of  0.30 m/s (1 fps)  through the grit chamber.   The comminutor, with 9.5 mm
 (3/8 in)  horizontal  slots,  screens  and shreds large solids  into  smaller parti-
 cles prior to  further treatment.  The comminutor  was  designed for a flow of
 5678 m-Vday (1.5 mgd)  with  a peak capacity of 263500  m3/day (7.0 mgd).

 The primary clarifier has a diameter of  15.2  m (50 ft) and  a sidewater  depth of
 2.4 (7  ft  10 in).  At  the design flow of 5678  m3/day  (1.5 mgd) the  clarifier
 detention  time is  2  hours,  the overflow  rate  is 31  m/day (760 gpd/sq  ft)   and
 the weir overflow  rate is 128  m2/day (10,270  gpd/lf).  The  primary  clarifier is
 equipped with  mechanical  scraper arms  for  sludge  removal.   Primary  clarifier
 underflow,  which consists of primary sludge and recirculated secondary  sludge,
 is  conveyed  to the tertiary thickener  by a piston  pump.  Floatable  material  in
 the primary  clarifier,  which includes  recirculated  scum  from the  secondary
 clarifier,  is  collected  in  a scum box  and discharged  for further  treatment and
 disposal.  The solids  handling  facilities for  the  secondary and tertiary  treat-
 ment units  are described  later.

 After primary  settling, the  sewage passes through  a high-rate, stone media
 trickling filter that  is  18  m  (60 ft)  in diameter and 1.8 m (6 ft)  deep.  The
 hydraulic loading at 5678 m3/day (1.5 mgd) is  22 m/day (23 mgad)   and the  organic
 loading is 780  kg BOD/day/1000 m3 (49  Ibs BOD/day/1000 cu ft).   Although  the
 trickling filter was designed for recirculation, this method of operation is not
used due to hydraulic  limitations of the bypass Control Box #1 which is located
between the primary clarifier and trickling filter.

The secondary  clarifier is 15.2 m (50 ft) in diameter, and  has a  sidewater depth
of  2 m  (6 ft 10 in).   At a plant flow of 5678 m3/day  (1.5 mgd)  the clarifier
has a detention time of 1.77 hours,  an overflow rate of 31  m/day   (760 gpd/sq ft)
and a weir overflow rate of  128 m2/day (10,270 gpd/lf).   The secondary clarifier
                                      10

-------
         Grit     Bar
        Chamber Screen
         Bypass            Bypass           Bypass
_ .       Control   _ .  ...     Control c     ,    Control
Primary   _       Trickling   _     Secondary ^QX
Clarifier  .,   ,     Filter    ..  n   Clarifier  .,  0
         No. 1             No. 2            No. 3
       • • ^^^^     ^-^^^^^      ^"^^   f~      1^1 •—«—
                                      D
                                      Bypass ch|orine
                                      00"'1"0'  Contact
                                                                      Tertiary
                                                                      ,nf|uent
                                                                      Pumping

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Trickling Filter
Recirculation
Pump Station
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                                                              I    I
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                      Supernatant! i
                                                      Secondary Sludge
                                                        Pump Station
I      ISupernatc
                Sludge
               Digester
Wet Wellt
   #3   u
                   Tr
                   J!
                                                 Sand Drying Beds
                                                   LEGEND
                                                     Wastewater  Piping
                                                           —•——• Sludge  Piping
                                                                  Scum Piping
                                       Sludge     Tank Truck
                                    Holding Tank Loading Area

FIGURE  4-1.  FLOW  DIAGRAM OF ELY SECONDARY WASTEWATER TREATMENT PLANT

-------
 equipment includes a sludge rake,  scum scraper arm,  and scum collection box.
 Secondary sludge is pumped to the  primary clarifier  where it is resettled
 with the primary sludge.

 The secondary clarifier effluent passes through the  existing chlorine contact
 chamber of the secondary plant.  The chlorine  contact  chamber has  been modi-
 fied to include flow measuring and sampling equipment.   Chlorine is  not added
 at  any point  in the chlorine chamber but instead is  added subsequently in the
 tertiary plant.

 B .   Tertiary
 Tertiary  treatment  includes  flow  equalization,  two-stage  lime  clarification,
 dual  media  filtration  and  chlorination.   Schematics  of  the  tertiary  facilities
 are shown in  Figure '4-2  and  in  Figures A-l  and  A-2.  The  design  criteria  are
 listed  in Table A-l, and the hydraulic   schematic  is shown  in  Figure B-l.  The
 influent  wet  well,  which has a  capacity  of  208  m3  (55,000 gallons) receives
 secondary effluent, overflows from the lime  clarifiers, flow from  the three
 tertiary  plant sample  sinks, and  the  flow from  the north  side  floor  drains.
 The wet well  provides  some equalization  of  flow.  Two variable-speed centrif-
 ugal  pumps  controlled  by a manually operated pump controller,  lift the waste-
 water from  the influent  wet  well  to the  mix  zone of the first  lime clarifier.
 Each  pump has a maximum  capacity  of 4.2  m3/min  (1100 gpm) at a TDH of 20 m
 (65 ft).

 The first -stage lime clarifier  is 17 m (55 ft)  in diameter with  a sidewater
 depth of  6  m  (19 ft 6  in)  (Figure A- 3) .   At a flow of 5678 m3/day  (1.5 mgd)
 the detention time  is  5.3 hours and the  overflow rate is 26 m/day  (631 gpd/
 sq ft) .   The volumes of  the  mix zone, flocculation zone and clarification
 zone  are  28 m3 (7,330  gal),  92 m3 (24,300 gal)  and 1,135 m3 (300,000  gal),
 respectively.

 Secondary effluent, slaked lime, and polymer are pumped to the mix zone of the
 clarifier.  Powdered carbon  can also be  fed at  this point.  A variable speed
 turbine creates an upward flow through the mix  zone draft tube and draws solids
 into  the  mix zone for  coagulation.  A sludge scraper, two inches above the
 clarifier floor,  rotates slowly and moves sludge gradually to the center sump.

 Effluent  from the first-stage lime clarifier flows by gravity to the  second-
 stage lime clarifier (Figure A-4)  .  Carbon dioxide dissolved in water is fed
 to the mix  zone of the second stage to precipitate CaC03 and reduce the pH to
 about 9.6.  Ferric chloride,  slaked lime, polymer, and powdered carbon can
 also be added to  the mix zone of the second -stage clarifier.

The design flow through the second-stage  lime clarifier is 5678 m3/day
 (1.5 mgd)  plus a  757 m3/day  (0.2 mgd)  feed stream of recycled tertiary efflu-
 ent containing dissolved carbon dioxide for pH control.   The surface area is
 identical  to that of the first-stage lime clarifier,  however,  the overflow
 rate is 29 m/day  (715 gpd/sq ft).   The second stage has  a sidewater depth of
 5 m (16 ft 6 in)  and a detention time of 4.5 hours.   The mix zone volume,
                                      12

-------
      Trickling     Tertiary Influent
      Filter Plant   Pump Station
                                                                              Filter
                                                                              Backwash
                                                   H2S04
                                                   •FeCLa   Dual-Media Filters
Primary/Secondary J
   Sludge j
                                                                 —ITank Truc_k
                                                                   [Loading Area
                                                                                               SHAGAWA
                                                                                               LAKE
                                                                                       Filter Backwash
                                                                                         ualization Tank
                Wet Well #3 HI    h
                                   _._.._}_,
^                                                                         Supernatant

                                                                         i'eTt'WasTT' I
    Lift Sta. #2
                           Sludge  Holding  j
                               Tank       i
                                                                               LEGEND

                                                                          	Process Flow

                                                                          	-Sludge  Flow
                                                                                , Process
                                                                                 Return Flow
               'STINKY DITCH"
                                                         Sludge
                                                       Holding Pond
FIGURE 4-2.  FLOW DIAGRAM  OF  ELY  TERTIARY WASTEWATER TREATMENT PLANT

-------
 flocculation zone volume,  and clarification zone volume are 23 m3 (6,130
 gallons),  77 m3 (20,400 gallons)  and 954 m3 (252,000 gallons), respectively.
 Each lime  clarifier has a  maximum hydraulic capacity of 11,356 m3/day
 (3,0 mgd).   The two lime clarifiers  each have overflow drains  and each clari-
 fier can be emptied by gravity to one foot  above the floor level.

 Affixed to  each lime clarifier is a  sample  sink  equipped with  a pH meter and
 sample  ports.   Sample lines  lead  from the upper  mix  zone,  lower mix zone,
 upper flocculation and lower flocculation zones,  and effluent  weir to the
 sample  sink.  A port for a variable  depth sampler is also  located at the
 sample  sink.  The pH,  solids volume,  and sludge  blanket depth  can be monitored
 at the  sampling sinks.

 The  second-stage lime  clarifier effluent flows by gravity  to a splitter box
 which splits  the wastewater  into  four equal  streams  and directs the wastewater
 to the  gravity  filters.  Chlorine, sulfuric  acid,  and  ferric chloride can be
 added to the  second-stage  effluent ahead of  the  splitter box.   Each of the
 four gravity  filters (Figure A-5)  is  3.7 m  (12 ft) in  diameter,  4.9 m (16 ft)
 high, and has a surface  area of 10.5  m2  (113 Sq  ft).   The  design hydraulic
 loading is  5.6  m/hr  (2.3 gpm/ft2)  at  5678 m3/day  (1,5  mgd)  and the design max-
 imum hydraulic  loading to  the filters is 8.6 m/hr  (3.5 gpm/ft2).   The filter
 media consists  of a  0.6  m  (2  ft)  layer of anthracite above a 0.3m  (l ft) layer
 of sand.  The anthracite has  an effective size of  0.8  to 0.13 mm with a uni-
 formity coefficient  of 1.7.   The  effective size of sand is 0.4 to  0.5 mm with
 a uniformity coefficient of  1.4 minimum  to 1.65 maximum.

 The  gravity filters  can  be backwashed automatically  on the basis  of either
 elapsed time or head loss, or backwashing can be  initiated manually.   Normally
 the  filters are  backwashed automatically every 24  hours.   While  one filter is
being backwashed,  the  other  three filters remain in  service,   The  backwash
water is held in  a 26 m3 (6,930 gallon)  chamber on the  top of  each filter
 (Figure A-5).  The backwash  cycle includes 5 minutes of air scour  at  1.5 m/min
 (4.9  scfm/ft2)  and a backwash rate of 0.61 m/min  (15 gpm/ft:-) until  the  cham-
ber  is  empty.

The effluent from the gravity filters  flows  to the effluent water  pump  station
 (Figure 4-2) and  is either discharged to  Shagawa Lake or is recycled  through
the tertiary plant.  From 15 to 25 percent of the  filtered wastewater  is re-
cycled through the tertiary plant as process water.  The tertiary plant can
use both city water or recycled effluent  for the plant processes.  Normally,
recycled effluent is used for all process purposes except to mix polymer.
Process water is used for:

        dissolution of CO-  and Cl2

        slaking CaO and as  lime ejector water

        bearing water to the fiber bearings  of the two lime clarifiers
        and the sludge thickener
                                      14

-------
      0  tertiary influent pump seal water

      0  sludge pump flushing water

      0  powdered carbon wetting and transport

      0  vacuum filter belt wash water

      0  tertiary plant cleanup

The treated wastewater not recycled passes through the parshall flume to
Shagawa Lake.  The parshall flume is both a flow metering station and a sam-
pling station.  The parshall flume meters and samples automatically the ter-
tiary plant effluent and any tertiary plant bypass.

The tertiary plant is designed so that the treatment units can be combined
into various treatment systems.  The two-stage lime clarifiers are operated
in series with the second-stage clarifier effluent being split among the four
parallel gravity filters.  The clarifiers are piped so that they may be oper-
ated in parallel.  The lime clarifiers, gravity filters, and the effluent res-
ervoir can each be bypassed for maintenance and repair.

Sludges from the first and second-stage lime clarifiers and sludge from the
trickling filter plant are normally pumped to an 8 m (26 ft) diameter x 5 m
(16 ft 6 in) high picket-type gravity thickener.  The sludge can also be routed
to a 757 m3 (200,000 gallon) emergency holding pond, to a tank truck loading
station, or to the vacuum filter.

Thickener underflow is pumped by a variable speed progressive cavity pump to a
1.8 m (6 ft) diameter, 2.5 m (8 ft) face belt type vacuum filter.  Filter cake
is discharged via conveyor to hoppers where it can be loaded by gravity into a
dump truck for ultimate disposal in a sanitary landfill.  Thickener underflow,
in an emergency, can be discharged to the 757 m3 (200,000 gallon) sludge hold-
ing pond.  The thickener supernatant is pumped via lift station #1 to the head
of the secondary plant.

C.  Appurtenant Equipment

The chemical feed systems include lime, ferric chloride, sulfuric acid, carbon
dioxide, chlorine, polymer, and powdered carbon.  Pebble lime (CaO) is stored
in two 18 ton (metric), (20 ton) storage bins.  The bins discharge directly to
duplicate paste slakers.  The slaked lime is transported to the first-stage
lime clarifiers by a system of hydraulic ejectors.  The lime feeder belt speed
is proportioned to the influent flow and the lime dose is set manually by means
of a timer mechanism which turns the feeder on and off.  The maximum capacity
of each lime feeder is 454 kg/hr (1,000 Ibs/hr),  Lime usage is determined
from reading the lime slaker totalizer daily.

Ferric chloride is stored in a 23 m  (6,000 gallon) tank which supplies two
0.11 m  (30 gallon) day tanks.   Two flow-proportional diaphragm pumps feed
                                      15

-------
      to the  second-stage  lime clarifier and to the influent pipe to the
 splitter box.  The  iron dose is set by pump stroke frequency, which is propor-
 tional to the influent flow, and by manually adjusting the stroke length,  A
 daily average Fed3 dose is calculated by measuring the drop in the day tank
 level.

 Sulfuric acid is stored outside of the building housing the tertiary plant in
 a  15 m3  (4,000 gallon) tank.  The acid is pumped by a flow-proportional dia-
 phragm pump to a point in  the pipeline ahead of the splitter box.

 Chlorine is purchased in 68 kg (150 Ib) cylinders.  Two cylinders are used
 simultaneously.  A flow proportional chlorine feeder, using recycled plant
 effluent, feeds chlorine to the splitter box influent pipe and to the effluent
 from the gravity filters.  Average daily chlorine dose is determined from
 change in weight of the chlorine cylinders.

 Liquid carbon dioxide, used for pH control, is stored in a 22 metric ton
 (24 ton) refrigeration unit and is vaporized and dissolved in approximately
 750 m3/day  (0.2 mgd) of recycled plant effluent.  The C02 dosage in pounds/day
 is read from the gas feeder 24 times per day, and the calculated dosage is the
 average of the 24 readings.

 Powdered activated carbon is purchased in 20 kg (45 Ib)  bags  which are stored
 in a room with only non-spark switches and equipment.   The powdered carbon
 feed system includes a hopper,  a volumetric feeder, ejector system and piping
 to the mix zones of both clarifiers.   The powdered carbon feeder is not flow
 proportional.

 Dry polymer is dissolved in city water and pumped to the first-stage lime
 clarifier by a pump that is not flow proportional.  Initially,  a commercial
 polymer mixer was used but it often plugged and failed to operate.   Polymer is
now added by hand and mixed with city water in a day tank.   There have been no
maintenance problems using manual polymer makeup during  a one year operating
period.   Polymer dosage is calculated from the daily inch drop in the day tank
 and the calculated concentration of polymer per inch of  tank depth.

 In case of power failure,  a diesel-powered emergency generator ensures con-
tinued operation of the tertiary plant.   Equipment connected to the emergency
generator include:

        Lights in emergency generator room

        One influent sewage pump

        One lime slaker

        Boiler,  heating units

     0   Air exchangers

        Two effluent pumps
                                      16

-------
      0  Turbine and sludge rake for both lime clarifiers

      0  Exhaust fan above gravity filter pit

         One underflow pump

      0  Thickener drive

      0  Carbon dioxide refrigerator and compressor

      0  All sump pumps

      0  Service water pumps

 The tertiary plant is totally housed in a 2004 m2 (21,570 sq ft)  building.
 Included in the building are a 130 m^ (1400 sq ft)  office and analytical lab-
 oratory area, work bench, showers, rest rooms, operator control  room;  opera-
 tional panel with an annunciator tied into the equipment, three  large  ventila-
 ting units, a boiler, emergency generator, and auxiliary equipment.   Two addi-
 tional storage areas were constructed because of the great need  for a  place to
 store spare parts, laboratory chemicals,  emergency heaters,  etc.

 D.   Analytical Program and Sample Scheduling

 Flow proportional wastewater samples are  composited at  two locations in the
 secondary plant and six locations in the  tertiary plant.   Sample  locations  are
 between the comminutor and primary clarifier ("Raw Sewage"),  the  chlorine con-
 tact chamber ("Secondary Effluent"), the  pipe ahead of  the magnetic flow meter
 for the first-stage lime clarifier,  the effluent weir of the  first-stage clar-
 ifier ("Influent second-stage lime clarifier"),  the effluent  weir of the
 second-stage clarifier,  the splitter box  for gravity filter  influent,  the
 viewing well ("Gravity filter effluent"), and the effluent metering station
 ("Effluent-discharge to Shagawa Lake").

Sludge samples are taken of the combined primary-secondary sludge from the
primary clarifier underflow ("Primary-secondary sludge"), from the first-stage
lime clarifier underflow, second-stage lime clarifier underflow,  and the vac-
uum filter sludge cake.  A sample of the sludge thickener supernatant,  which
is recycled to the head of the secondary plant, is also  taken.  The  plant
operators obtain and composite flow-proportional samples from each location
as described.  The samples are picked up each midnight and delivered to the
laboratory the next day.  The analytical sampling and analysis schedule, shown
in Table 4-1, indicates the sampling frequency, compositing method,  and
frequency of analytical testing.
                                      17

-------
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-------
                                   SECTION V

                              PROCESS  PERFORMANCE
 A.   Secondary Plant

 The  influent  flow  to  the  trickling  filter plant  includes wastewater  from the
 City of Ely and  discharges  through  three package lift  stations  adjacent to the
 plant site  as shown in  Figure A-l.  Tertiary plant return  streams  flow to the
 208  m3 (55,000 gallon)  equalization sump of lift station #1  and are  pumped to
 the  plant influent.   Lift station #2 pumps water from  a creek,  "Stinky Ditch",
 which contains some septic  tank  drainage, and also pumps the runoff  from the
 sludge holding pond.  Lift  station  #3 picks up the swamp water  situated east
 of the trickling filter plant and discharges it  to the plant influent sewage
 pipe.

 Influent to the  trickling filter plant averages  4,163 m^/day (1.1  mgd).  For
 eight months  of  data  as shown in Table C-l, Appendix C, total phosphorus aver-
 aged 7.07 mg/1,  SS averaged 202  mg/1, alkalinity averaged  181 mg/1 as CaCO-,
 BOD  averaged  90  mg/1  and  the median pH was 7.9.

 Eight months  of  trickling filter plant performance data, as shown  in Tables
 C-2  and C-3,  Appendix C,  were obtained during the first year of the project.
 The  trickling filter plant removed  an average of 46 percent of the total phos-
 phorus, 78 percent of the suspended solids, 21 percent of  the alkalinity and
 57 percent of the BOD.  The concentrations in the trickling filter plant efflu-
 ent  averaged  3.81 mg/1 total P,  44 mg/1 SS, 139  mg/1 alkalinity, and 39 mg/1
 BOD.   The effluent median pH was 7.3.

 B.   Tertiary  Plant

      1.  Two-Stage Lime Clarification

         Phosphorus Removal

During normal  operation the pH in the  first-stage lime clarifier was raised to
 11.8 or higher by the addition of slaked lime to precipitate hydroxyapatite
and magnesium hydroxide.  The operating pH, lime dose required,  incoming alka-
 linity, and first-stage effluent total  phosphorus concentration for the first
year of operation are shown in Figure  5-1.   As  can be seen in the figure,  ther
pH varied between 11.84 and 12.03 and  the lime  dose varied between 266 and
344 mg/1.   For this period of operation,  total  phosphorus  in the first-stage
 clarifier effluent averaged 0.298 mg/1.
                                      19

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  u. os
    ,
  o
  -
.6


.5


.4


.3


.2
FIGURE 5-1.  MONTHLY AVERAGE VALUES OF INFLUENT ALKALINITY,
            LIME DOSE, CLARIFIER  pH, AND EFFLUENT TOTAL P FOR
            FIRST STAGE LIME CLARIFIER.
                             20

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 The second-stage lime clarifier was operated at a pH of 9.6 and was originally
 designed so that C02  following dissolution could be  added  to  the influent  of
 the second-stage clarifier.   Shortly after start-up,  the influent pipe  plugged
 with CaC03 and had to be  taken apart and  cleaned.  To avoid this frequent
 occurence,  the situation  was  corrected by adding dissolved CCU  directly to the
 second-stage mix zone instead of to  the influent pipe.  Also  during start-up
 it was  determined that the  effluent  from  the  second-stage  clarifier was very
 unstable and CaCOg was being  precipitated on  the filter media.   Although de-
 posited CaCOj removed soluble phosphorus  to very low  levels,  high head  losses
 and short filter runs resulted.   This  problem was  resolved after the sulfuric
 acid feed system was  placed in operation  to reduce the second-stage effluent
 pH from a range of 7.6 to 9.5 to a range  of 7.5  to 7.8 thereby  producing a
 negative Langelier index.   While this  resulted in  dissolution of the carbonate
 deposit and prevented further precipitation,  soluble  phosphorus was no  longer
 removed by the filters.

          Effect of Solids Volume on  Phosphorus Removal

 During  the  initial  stages of  plant operation, it was  observed that  the  volume
 of solids in the mix  zone and the ratio of upper mix  zone  solids  volume to
 lower mix zone solids volume  were critical in the  control  of  the  performance
 of the  two  lime clarifiers.   The solids brought  into  the mix  zone provided
 surfaces  which theoretically  promote the  completion of chemical  reactions  and
 improve flocculation.

 Therefore,  a procedure was  initiated through which the solids volume in the
 mix  zone  of the lime  clarifiers  was controlled by  sampling and  testing  the
 upper and lower mix zones on  an  hourly  basis.  The test involved  filling a
 one  liter graduate and allowing  30 minutes for the sample  to  settle.  After
 30 minutes  the  solids  level in the graduate was read  and recorded in milli-
 liters  per  liter.  Through this  procedure, it was determined  that a  satisfac-
 tory upper  mix  zone solids volume in the  first-stage  lime  clarifier  ranged
 from 140  ml/liter to  280  ml/liter.  As  seen in Figure 5-2,   the  total phos-
 phorus  removal  was 91  percent  or greater  when the upper mix zone  solids volume
 averaged  140  ml/liter  or more.   When the  upper mix zone solids volume de-
 creased to  84 ml/liter, total phosphorus  removal by the first-stage clarifier
 dropped to  84 percent.

 In the  second-stage lime clarifier sufficient solids  in the upper mix zone
 also resulted in satisfactory total phosphorus reduction.   As shown in  Figure
 5-3, when the upper mix zone solids volumes averaged  less than  70 ml/liter,
 total phosphorus removal ranged  from 51 to 67 percent.  When the upper mix
 zone solids volume was greater than 140 ml/liter, total phosphorus removal
 ranged  from  72 percent to 84 percent, and total phosphorus  concentration in
 the clarifier effluent averaged  0.04 to 0.06 mg/1.

A second operational parameter used for clarifier operation was  the ratio of
upper mix zone solids volume to the lower mix zone solids  volume.  As an oper-
ational tool it indicated whether the turbine speed was great  enough to pump
                                     21

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                       100_
                        95
                      LU
                      ee.
                        90
NJ
N)
                      co
                      O
85
                      O 80
                                   I
                   I
I
I
 I

250
                          0       50      100      150      200

                                  UPPER MIX ZONE SOLIDS VOLUME,  ml/liter

                  FIGURE 5-2.  INFLUENCE OF UPPER MIX ZONE  SOLIDS VOLUME ON
                              TOTAL PHOSPHORUS REMOVAL IN FIRST STAGE LIME
                              CLARIFIER.
_J

300

-------
  <
  o
    200 i—
FIGURE 5-3. MONTHLY AVERAGE VALUES OF UPPER MIX ZONE
          SOLIDS VOLUME, PERCENT TOTAL PHOSPHORUS
          REMOVAL,  AND TOTAL PHOSPHORUS CONCENTRATION
          IN SECOND STAGE LIME CLARIFIER EFFLUENT.
                           23

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sufficient solids into the mix zone.  Although the equipment supplier recom-
mended a ratio of 0.95 for both clarifiers, operating experience proved other-
wise.  First-stage total phosphorus removal was satisfactory with a ratio
above 0.72, and very good removal was attained at a ratio between 0.85 and
0.90.  In the second-stage clarifier, the most effective ratio was normally
between 0.75 and 0.90.

Because of the very good mixing in the second stage, the turbine speed was
rarely adjusted in this unit.  Occasionally the turbine would not pump suffi-
cient solids to the upper mix zone of the second-stage presumably because the
intake to the turbine was blocked by heavy solids.  This situation was cor-
rected by temporarily increasing the speed of the sludge rake and by increas-
ing sludge withdrawal.

         Control of the Solids Blanket

The sludge blanket depth in the lime clarifiers refers to the depth of solids
which exist beneath the solids-liquid interface.  It was necessary to con-
trol the blanket level so that it was high enough to provide solids for the
mix zone, yet low enough to prevent solids carryover to the effluent weir.
While the blanket depth was influenced by operating conditions, it was con-
trolled principally by the sludge blowdown rate.  The blowdown rate was regu-
lated by the balance between sludge pumping rate and pumping interval.  Ordi-
narily the pump speed was held constant while the blowdown rate was adjusted
by increasing or decreasing the duration of the on/off pumping cycle.

In the first-stage lime clarifier the characteristics of the solids blanket
depended on lime dosage, polymer addition, and flow, in addition to the sludge
blowdown rate.  Lime dosage was adjusted according to pH requirements however,
a large increase in lime dosage increased solids and thus added to the blanket
depth.  As a general rule, lime dosages were not increased specifically to
build the solids blanket.  (Flow and polymer addition are discussed later.)
The average depth of the first-stage solids blanket was 1.8 m (6 ft), ranging
from 1.4 m (4.5 ft) to 2.7 m (9 ft).

In the second-stage clarifier, the solids blanket, a combination of heavy cal-
cium carbonate and iron precipitate, varied from less than 0.6 m (2 ft) to
1.8m (6 ft) in depth.  Experience demonstrated that a blanket depth of 1.2 m
(4 ft) provided optimum percent removal of total phosphorus by the unit.  The
solids blanket was held at this level during the months of September, October,
and December, 1973 and January and February, 1974 when the percent removal of
phosphorus was relatively high.

Although the clarification process could be operated either with or without a
sludge blanket, the existence of a blanket in the second stage aided solids
capture.  However, it was observed that after the solids blanket had aged for
several weeks, solids capture became optimum.  For example, the second-stage
clarifier was refilled October 31, 1973.  By November 7, soluble phosphorus in
the second-stage effluent was 0.029 mg/1 and the particulate: phosphorus was
0.045 mg/1.  During the following two weeks, the sludge blanket depth stabil-
ized at 1.2 m  (4 ft) and particulate phosphorus decreased to a low of 0.017
mg/1.  Only a slight increase in soluble phosphorus removal was noted.  On


                                      24

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another occasion when the second-stage clarifier was again refilled, support-
ing data were obtained further demonstrating that solids capture in the clari-
fier improved as the solids blanket aged.

         Chemical Addition (Cationic Polymer in First Stage)

Polymer addition to the first-stage lime clarifier began in April 1973.  Ini-
tially, a cationic polymer, Betz 1150, was used at a dosage level of 0.53 mg/1.
In early May, Betz 1200 was substituted for Betz 1150.  Betz 1200 was more
viscous and difficult to dissolve so on May 10 polymer addition was discontin-
ued.  On May 23 an attempt was made to feed Betz 1130 but it too was difficult
to dissolve and to pump.  On June 1, addition of Betz 1150 to the first-stage
clarifier began again at a dosage level of 0.20 mg/1.  This dose appeared
effective in controlling the solids blanket.

The addition of Betz 1150 improved process performance through better mangage-
ment of the solids inventory, and by permitting a lower blowdown rate to main-
tain the proper sludge blanket depth.  When polymer addition was stopped, the
first-stage solids blanket rose rapidly.  When polymer was again added, the
blanket depth decreased and stabilized near 1.8 m (6.0 ft).  Other than pre-
venting solids carryover, polymer addition seemed to have no influence on
first-stage clarifier effluent quality.

         Chemical Addition (Iron in Second-Stage Clarifier)

Beginning in March 1973, ferric chloride was added to the mix zone of the
second-stage lime clarifier.   The dosage was 6.0 mg/1 as Fe+3.

Theoretically, some hydrolysis products of Fe+^ ion causes coagulation of
phosphorus (2).   Although FeP04 is considered to be mostly soluble in neutral
and alkaline wastewater, some hydrolyzed Fe"1"^ compound presumably coagulated
the phosphorus at the second stage pH of 9.6 and thus aided in total phos-
phorus removal (3).

For a two-week period in June and July, the FeClj dosage to the second lime
clarifier was reduced significantly.  The total phosphorus removal by the
second-stage clarifier as a function of ferric chloride dosage is shown in
Figure 5-4.  From June 28 to July 7, when the FeClg dosage was reduced from
5.2 mg/1 to 2.2 mg/1, the total phosphorus removal deteriorated from an aver-
age of 65 percent to less than 50 percent.  In addition, the solids volume in
the upper mix zone decreased along with the decrease in the iron dose.
Whether the decrease in the iron dose or the decrease in the solids volume     ,
caused the reduction in total phosphorus removal is not clear.

It was concluded that a minimum iron dosage, somewhere between 3.0 and 6.0
mg/1 as Fe"1"^, was needed to ensure adequate phosphorus removal and to improve
clarification.
                                      25

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  80
^o
Jf70

O
ui
at
  60
of.
O
  50
  40
  30
        1
                         V
            _L
I
I
I
I
    01234567
          IRON DOSE, mg/l  as Fe+3
FIGURE 5-4.  INFLUENCE OF IRON DOSE ON TOTAL
            PHOSPHORUS REMOVAL IN SECOND
            STAGE LIME CLARIFIER.
                     26

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          Effect of Flow on Performance of Lime Clarifiers

The tertiary plant influent flow averaged 4315 m3/day (1.14 mgd) for 12 months
and on a monthly average basis varied from 3104 m^/day  (Q.,82 mgd) to 5678
m3/day (1,50 mgd).  The minimum daily flow was 2877 m^/day (0,76 mgd) and the
maximum daily flow was 8706 m3/day (2.3 mgd).  The second-stage lime clarifier
influent flow included the first stage flow plus 757 m3/day (0.2 mgd) of recir-
culated tertiary treated water used for CC>2 dissolution,

There was some indication that large variations in the flow through the first-
stage lime clarifier affected total phosphorus removals in the first-stage
clarifier.  High flows caused the solids blanket in the first-stage clarifier
to rise rapidly.  For example, when high flows were experienced in July, the
solids blanket rose to over 4.8 m (16 ft) allowing carryover of particulate
phosphorus.  The first-stage effluent total phosphorus on July 18 was 0.83 mg/1,
which was about three times the normal monthly average.   On the other hand, in
October when heavy rains again occurred,   the sludge blowdown rates were in-
creased soon enough to prevent the carryover of phosphorus-laden solids.  The
major difference in the operation of the first-stage lime clarifier during
these two instances of high flows was the control of the solids blanket in
order to prevent solids carryover.

Unlike the performance characteristics just described for the first-stage clar-
ifier, large increases in plant flow did not greatly influence the solids blan-
ket level in the second-stage lime clarifier nor did they greatly affect phos-
phorus removal in the second-stage clarifier.  This contrast in clarifier per-
formance is shown in Figure 5-5.  When the daily flow averaged about 3780 m3
(1.0 mgd) prior to October 8, total phosphorus removal was 95-96 percent in the
first stage and 85 percent in the second stage.  When the plant flow increased
between October 8 and October 17, phosphorus removal in the first stage dropped
from 95-96 percent to about 90 percent while phosphorus removal in the second
stage remained fairly stable.

It should be noted that during the periods of high plant flows resulting from
rainstorms, the chemical consumption for coagulation did not increase propor-
tionately because there was a dilution of influent alkalinity.

          Phosphorus Removal Summary

Two lime clarifiers operating in series removed 98.2 percent of the tertiary
plant influent total phosphorus during a 12-month period.  The first stage
total phosphorus removal ranged from 84 percent to 95.5 percent.  During the
same period of time, the second-stage lime clarifier reduced total phosphorus
in the effluent of the first lime clarifier by an average of 72.2 percent,
ranging from a low of 49 percent to a high of 84 percent.  Variation in plant
operation, including draining of the second-stage clarifier,  accounted for
occasions of poor phosphorus removals.  Total phosphorus concentration in the
first-stage effluent varied from a low monthly average of 0.20 mg/1 to a high
of 0.57 mg/1 (Appendix D).   The second-stage lime clarifier effluent total
phosphorus varied from a low of 0.034 mg/1 to a high of 0.171 mg/1.
                                       27

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m.o 100
o^
<_J-
£<  90
i°
o[f  80
                                MONTHLY AVERAGE OF DATA
     t-._,_»_.S __...'
   70 U—L
                     * i i
                                   i  i i  i

  O  94
  LU
  O
  ^  90
     88
          i  i  i  i i  i  i  i i i  i  i
•o
t  2.2
^  2.0
O  1.8
^  1.6
^  1.4
2  1-2
^  1.0
>  0.8
          iii
       1
                    10       15       20
                          OCTOBER, 1973
25
30
    FIGURE 5-5. INFLUENCE OF TERTIARY PLANT FLOW ON TOTAL
                PHOSPHORUS  REMOVAL BY  FIRST STAGE AND
                SECOND STAGE CLARIFIERS.
                             28

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         Suspended Solids Removal

The monthly average suspended solids concentrations in the tertiary plant in-
fluent, the first-stage lime clarifier effluent, and the second-stage clarifier
effluent are shown in Figure 5-6.  The variability observed in the influent
solids is due to the fact that the tertiary plant influent flow included the
trickling filter plant effluent together with flow from the tertiary plant
sample sinks and floor drains.  The mean monthly tertiary plant influent sus-
pended solids concentrations were as low as 36 mg/1 and as high as 122 mg/1
with a 12-month average of 70 mg/1.

Influent suspended solids increased significantly on four occasions when the
second-stage lime clarifier was drained.  Draining a lime clarifier returned
the contents of the clarifier to the tertiary influent wet well.  The points
shown separately in Figure 5-6 for the months of October, February and March
represent the increment added to the monthly average values by the clarifier
solids.

Although the suspended solids to the first stage varied considerably, the con-
centrations in both the first-stage and second-stage effluents were stable, as
shown in Figure 5-6.  The first-stage effluent SS monthly average varied from
7 mg/1 to 16 mg/1 with a 12-month SS average of 9.6 mg/1; and the second stage
solids varied from 3.5 mg/1 to 12 mg/1 with a 12-month average of 7.1 mg/1.

Optimum clarification in the second stage was desirable from the standpoint of
both solids and phosphorus removal.  Efficient solids removal was needed to
prevent high solids loading to the gravity filters which would have resulted
in shorter filter runs.  Also, if particulate phosphorus was not settled out,
it would have been resolubilized between the clarifier and filter when the
second-stage effluent pH was adjusted from 9.6 to less than 8.0.  This resolu-
bilized phosphorus would have escaped filtration and been discharged in the
final effluent to Shagawa Lake.  During the year of operation, even in the
month of poorest clarification by the lime clarifiers, the suspended solids
concentration was 40 percent of the discharge standard (30 mg/1).  This shows
that the standard could have been met without the use of a filter.

         Turbidity Removals

The influent turbidities to the first-stage lime clarifier were variable
throughout the year.  Minimum and maximum average monthly influent turbidities
were 10 JTU and 41 JTU, respectively.  The 12-month average was 23 JTU.  The
first-stage effluent turbidities were nearly constant after the initial months
of operation in April and May.  The average turbidity for those two months was
6.0 JTU, and the average turbidity during the remaining 10 months was 2.0 JTU,
varying from 1.3to 2.7 JTU.  Maintaining good control of the solids inventory
in the first-stage clarifier was the principal factor in lowering the turbidity
levels in the first-stage effluent.
                                      29

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 o>
 E
O
CO

O
LU
Q
o.
«/>
3
to
    120



    110



    100
    20
       •  FIRST STAGE INFLUENT    O


       A  FIRST STAGE CLARIFIER EFFLUENT


       •  SECOND STAGE CLARIFIER  EFFLUENT
O Indicates the influence on the monthly average

  SS values due to recirculation of the contents of

  the second  stage clarifier to the influent.
FIGURE 5-6.  MONTHLY AVERAGE  SUSPENDED  SOLIDS IN  FIRST

              STAGE   INFLUENT,  FIRST STAGE EFFLUENT AND SECOND

              STAGE  EFFLUENT.
                                   30

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As previously discussed, cationic polymer was useful in stabilizing the solids
blanket, which also resulted in lower first-stage effluent turbidities.  Even
with flows as high as 50 percent above design flow,  turbidity levels in the
first-stage effluent were consistently low except when the solids blanket was
allowed to overflow the weir.

The second-stage effluent turbidity is shown in Figure 5-7 together with the
total phosphorus and particulate phosphorus concentrations in the second-stage
effluent.  The second-stage effluent turbidity for 12 months averaged 2.0 JTU
with monthly averages ranging from 0.85 JTU to 3.4 JTU.  The U.S. Public
Health Service limits turbidity in public water supplies to 5.0 units  (4).
Particulate phosphorus, which is the difference between the unfiltered and
filtered phosphorus, was found to be directly related to effluent turbidity.
This would suggest that the particulate phosphorus could conceivably be moni-
tored by using a turbidimeter with a continuous readout.  Turbidity measure-
ments have been considered more relevant to water treatment than wastewater
treatment  (5).  To achieve the desired effluent total phosphorus concentration,
it was necessary to achieve a degree of clarification similar to that attained
in the treatment of potable water.  Turbidity measurement, therefore, became
a valuable tool in process control.  Turbidity analyses were also quicker and
easier to perform than suspended solids tests.  The first year's data indicate
that turbidity measurements could be used for process control with less reli-
ance on the more time consuming suspended solids analysis.

         Organic Removal

Routine analysis for total organic carbon did not begin until December 1973.
Thereafter, samples of first-stage lime clarifier influent, first-stage efflu-
ent, second-stage effluent, and tertiary plant effluent were analyzed twice
per week for TOC.  Table 5-1 shows the TOC removals through the two-stage clar-
ification  system.  The first-stage influent averaged 46.0 mg/1 for four months.
First-stage effluent and second-stage effluent TOC averaged 23 mg/1 and 18.5
mg/1, respectively.  The first-stage lime clarifier removed an average of 49
percent of the influent TOC, while the second-stage lime clarifier removed
only 9 percent of the tertiary plant influent TOC.  Together, the two  lime
clarifiers removed 60 percent of the tertiary plant influent TOC.  Whether TOC
removal, based upon data obtained in the winter months, could be extrapolated
for the whole year is not clear.  From December through March the flow was
relatively low and steady, unlike the rest of the year.

The TOC analysis schedule which was set up in December  1973 was expected to
continue through 1974.  During this time the effect of powdered carbon addi-
tion to the mix zone of the second lime clarifier was to be examined.

         Chemical Addition Prior to Gravity Filters

The effluent from the second-stage lime clarifier passed through the splitter
box to the gravity filters.  Chemicals were injected into the wastewater in
the pipe between the second-stage clarifier and the splitter box.  The chem-
icals included sulfuric acid for pH adjustment, ferric chloride for phos-
phorus removal, and chlorine for disinfection.  The pipeline turbulence was
sufficient to ensure good mixing.


                                      31

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              I—I	I    I    I
              I	I	I    I    I
       4.0
    9  2.0
    to
    OL
    D
    "-   0
J—I—I—I—I	I    I     I    I    I	I
    o>
    E
    o
    z
    LLJ
    Q.
    to
    3
    to
FIGURE 5-7.  MONTHLY AVERAGE CONCENTRATIONS OF SUSPENDED

            SOLIDS, TURBIDITY, PARTICULATE PHOSPHORUS AND TOTAL

            PHOSPHORUS IN SECOND STAGE CLARIFIER EFFLUENT.
                              32

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             TABLE 5-1  TOTAL  TOC  REMOVAL  BY TERTIARY LIME CLARIFICATION *
  PROCESS
                       Influent  (mg/1)          Effluent (rag/l)     % Reduction Thru Process
Range Average Range Average Range Average
First-stage
Clarifier
Second-stage
Clarifier
Two-stage
System
33-63 46 19-30 23 38-66 49
19-30 23 14-25 18.5 9-27 19
33-63 46 14-25 18.5 43-75 60
* Based on data Dec. 1973 - Mar.  1974

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 Sulfuric acid was added to the second-stage effluent which lowered the pH to
 about 7.5 prior to filtration.  At this pH, a negative Langelier Index was
 achieved which prevented deposition of CaC03 on the filters.   Acid addition
 also decreased the pH to within the 6.5 to 8.5 range required by the State of
 Minnesota, and no further pH adjustment was necessary before the treated
 wastewater was discharged to Shagawa Lake.

 Subsequent to initiation of pH adjustment of the filter influent, large
 amounts of scale were removed from the filters.   In April, the gravity filter
 influent and effluent Ca+2 concentrations were 57.3 mg/1 and 65.7 mg/1,
 respectively.  In May the filter influent and effluent Ca+2 averaged 39.3 mg/1
 and 49.7 mg/1, respectively (Appendix D).  The increase in calcium through the
 gravity filters was due to the dissolution of CaC03 scale that had built up on
 the filters prior to April, 1973.

 A^negative effect of lowering the filter  influent  pH with acid was the resolu-
 bllization of a portion of the remaining  particulate phosphorus.   The extent
 to which resolubilization occurred resulted in an  increase of soluble phos-
 phorus  in the filter influent from an average of 0.023 mg/1 to an average of
 0.065 mg/1.   Such a concentration was unacceptable since  soluble  phosphorus is
 unaffected by filtration and  a final  effluent concentration of 0.065  mg/1
 exceeded the design goal of 0.050 mg/1 total  phosphorus.

 In order to counteract  the  dissolution of particulate  phosphorus,  an  average
 of 2.66  mg/1  of ferric  chloride (as Fe+3)  was added to the filter  influent
 which served  to precipitate a portion of  the  residual  soluble phosphorus.
 Although dissolution  was still  experienced, the  increase  in soluble phosphorus
 was smaller,  and  the  filter influent  soluble  phosphorus concentration was re-
 duced to 0.043 mg/1.

 Chlorine for  disinfection was  dissolved using  treated  wastewater before being
 fed to the  filter  influent  stream.  Adding the chlorine prior to the  filters
 provided contact  time for disinfection  in  the  filtered backwash storage com-
 partment (Figure A-5).   The detention  time in  the backwash  compartment at a
 flow of  5678  m-Yday  (1.5 mgd) was  27 minutes.

 Grab samples  for coliform analysis were obtained from the effluent reservoir
 during the  10 months  of  operation between  June 1973 and March  1974.   The  grab
 samples  were  analyzed four times each week  for total coliform and once each
 week for fecal coliform.  In seven of the  10 months the presence of total coli-
 form was not  reported in any of the 100 milliliter samples.   In nine  out of the
 10  months there were no fecal coliform bacteria reported.  Out of approximately
 160 grab samples collected and analyzed for total coliforms, only six were
 found to have one or more total coliforms per 100 ml.

Without  chlorination, coliform reappeared in the  tertiary plant effluent.   In
October,  no chlorine was added for 3 days.  During  this 3-day period,  total
coliforms were found in two of the three grab samples and fecal coliforms were
present  in one of two grab samples.  The chlorine residual of  the  treated
                                      34

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wastewater was checked by the orthotolidine method every 2 hours.  From April
to October 1973, the combined chlorine residual averaged 0,50 mg/1.  When the
problem of a chlorine shortage evolved in the autumn of 1973, a lower dose,
resulting in a residual of 0.10 mg/1, was tried.  However, because a zero re-
sidual was observed on several occasions, dosage at a slightly higher level
was resumed.  Thereafter, the combined chlorine residual from November 1973
through March 1974 averaged 0,18 mg/1.

Chlorine dosages for the year averaged 3.0 mg/1.  From June to October the
mean dosage was 3.6 mg/1.  In November the chlorine dosage was reduced because
of the potential chlorine shortage.  The mean chlorine dosage for November
through March was 2,7 mg/1.

     2.  Dual-Media Filtration

         Phosphorus Removal by Dual-Media Gravity Filters

As seen in Table 5-2, an average of 85 percent of the influent particulate
phosphorus, which comprised 68 percent of the total influent phosphorus, was
removed by dual-media filtration.  The effluent particulate phosphorus concen-
tration averaged 0.008 mg/1, or 17 percent of the total phosphorus in the
effluent.

As shown in Table 5-2, soluble phosphorus passed through the gravity filters,
with the following exceptions.  In April, a period which in part preceded the
addition of H2S04 to the filter influent for pH adjustment, soluble phosphorus
was removed because of buildup of calcium on the filters.  In May, therefore,
during the period when CaC03 was dissolving off the filters, soluble phosphorus
showed an increase.  Upon achieving chemical equilibrium, the soluble phos-
phorus in the filter influent and effluent was essentially the same.

The effect of variation  in hydraulic  loading on total phosphorus removal by the
gravity filters is shown in Figure 5-8.  The points on the graph represent data
from 20 days of operation in each of  the three indicated months and the curve
is an  approximate fit to the averaged data for each of the three operating
periods.

The trend of the data indicates that  (a) a lower filter  loading resulted in a
greater percentage phosphorus removal while less phosphorus removal was
achieved at high filter  loadings, and (b) that during a  period of  operation in
which  wide  fluctuations  in hydraulic  loading were experienced  (as  in August),
a smaller percent phophorus removal resulted than when the filter  loadings were
low and consistent  (as in January).

         Suspended Solids, Turbidity, Iron, and TOG Removal

The performance of the gravity filters with respect to suspended solids, tur-
bidity, iron, and total  organic carbon is shown in Table 5-3.  The suspended
solids concentration in  the filter influent ranged from  5 to 15 mg/1, averaging
9 mg/1 for the year, and effluent suspended solids averaged  less than 1.3 mg/1.
Average suspended  solids removal  was greater  than  85  percent.   It  will  be
recalled that the  filters  also removed 85  percent  of  particulate phosphorus.
                                      35

-------
 TABLE 5-2  PARTICULATE AND SOLUBLE PHOSPHORUS REMOVAL BY DUAL-MEDIA
            FILTRATION
                  PARTICULATE PHOSPHORUS *
                                SOLUBLE  PHOSPHORUS
Month
April, 1973
May
June
July
August
September
October
November
December
January, 1974
February
March
Influent
(mg/1)
0,097
0.093
0,055
0.069
0.034
0.027
0.027
0.027
0.028
0.040
0.045
0.079
Effluent
(rog/1)
0,012
0.014
0.013
0.014
0.003
0.006
0.006
0.003
0.004
0.004
0.007
0.012
Percent
Removal
88
85
76
80
91
78
78
89
86
90
84
85
Influent
'(mg/1)
0.074
0,022
0,043
0.073
0.039
0.016
0.019
0.027
0.017
0.021
0.036
0.065
EfJ-luent
(mg/1)
0,058
0,046
0.033
0.062
0.038
0.016
0.017
0.029
0.017
0.022
0.036
0.065
Percent
Removal
22
<-•>-
23
15
3
0
11
--
0
--
0
0
Average
0.052
0.008
85
                               0.038
                               0.037
 * Particulate phosphorus = (total phosphorus) - (soluble phosphorus)

"* Soluble phosphorus refers to that portion of the total phosphorus which
   passes through a 0.45y membrane filter.
                                    36

-------
fe?


<
>
o

LU
tt
   70f-
   60
    50
    40
O
X
Q.
(/)

O
X
Q.

_,   30
    20
    10
                                  A  A   A    A
     0

     0
          A Aug. '73 Data  A Average Aug. Data


          D Sept. '73 Data  • Average Sept. Data


          O Jan. '74 Data  * Average Jan. Data

        AT |     |     |

      )" 1.4   U>   L8
                         I
                                 I
I
I
I
I
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                        .8   2.0  2.2  2.4   2.6  2.8   3.0  3.2   3.4  3.6


                 AVERAGE DAILY HYDRAULIC  LOADING, gpm/ft2


FIGURE 5-8.  EFFECT OF  HYDRAULIC LOADING ON TOTAL PHOSPHORUS

             REMOVAL  BY  DUAL-MEDIA FILTRATION.
                              37

-------
00
           Month
       Average
  Suspended Solids
        (mg/1)
Influent   Effluent
TABLE 5-3  GRAVITY FILTER PERFORMANCE

       Turbidity (JTU)
                     Iron as Fe
                        (mg/1)
Influent  Effluent  Influent  Effluent
                                                                                            TOG (mg/1)

                                                                                         Influent
April 1973
May
June
July
August
September
October
November
December
January 1974
February
March
5
15
7
8
7
7
6
7
9
9
10
14
<2 3.1
<1 5.9
<0 . 8 2.4
<;i,6 1.53
<1 1.21
<1 1.30
<1.7 1,48
<1 1.45
<1.4 1.83
<1 1.43
<1.5 2.19
<2 2.8
2.6
1.2
0.45
0,17
0.11
0.33
0.44
0.33
0.32
0.14
0.20
0.43


3.15
2.98
3.40
3,47
3,23
4,24


0,20
0.21
0.17
0.176
0,175
0.30




18.8
17,5
16,1
25,5




16.7
15.0
16.2
23.8
   8.7
        2.22
                                   0.56
                      3.41
                                                                                 0.21
                                                                   19.5
                                                            17.9
       Percent Removal
        >85%
             75%
                                                                           94%
                                                                        8%

-------
The turbidity data indicate a yearly average removal of 75 percent, and a
yearly average effluent turbidity level of 0.56 JTU,  However, it should be
recalled that during the first two months of operation the procedures for
chemical addition prior to filtration were being tested and the filtration
system had not yet attained equilibrium.  Therefore, during that period tur-
bidity removal averaged only 58 percent with an average effluent turbidity ot
1 9 JTU   After stable operation was achieved, turbidity removal increased to
an average of 83 percent and the effluent turbidity averaged a low 0.29 JTU.
These latter values are more representative of typical operation at the Ely
plant.

As shown in Table 5-3, the filters removed an average of 94 percent of the_
analytically determined iron from the filter influent.  There is some quali-
tative indication that higher influent  iron concentrations produce higher
effluent iron concentrations.  In March 1974, for example, the influent iron
concentration was 25 percent greater than the mean, and the effluent iron con-
centration was  43 percent above the mean.

Based upon four months of data, as  shown in Table 5-3, the gravity filters
removed negligible  amounts of TOG from  the wastewater.  Average removal was
8 percent and,  at best, was  14 percent.  It would appear  from the  data that
TOC remaining at this point  in the  treatment train  would be soluble  and there-
fore unaffected by  filtration.  Potentially, additional TOC could  be removed
by powdered  carbon  adsorption in  the second-stage lime clanfier with  subse-
quent removal of the powdered carbon carryover  by filtration.

          Filter Hydraulics

The hydraulic loading on the gravity filters varied considerably during the
one-year period of  operation due  to long-term  seasonal variations  in the  waste-
water flow and  also to  short-term flow  increases resulting  from stormwater  run-
off.  The filters were  designed for a  loading  of 5.6  m/hr (2.3  gpm/sq  ft)  at  a
flow  of 237  m3/hr  (1.5  mgd)  with  a  design maximum peak  loading  of  8.6  m/hr
 (3 5  gpm/sq  ft).   In practice, the  lowest and  highest average daily  hydraulic
loadings were 3.4 m/hr  (1.4  gpm/sq  ft)  and  9.3 m/hr (3.8  gpm/sq ft), respec-
tively.  The monthly mean  hydraulic loadings  ranged from  3.7  m/hr  (1.5 gpm/sq
ft)  to  6.4 m/hr (2.6  gpm/sq  ft).

The  permissible head  loss  across  the filter was about 3.0 m (10 ft).   The fil-
ters  were backwashed  automatically  every 24 hours  and only rarely  was  it nece-
 sary to backwash  more  often.   In  the low-flow months the  pressure  loss buildup
 seldom  exceeded.2.1 m (7 ft)  during a  24-hour  filter run.   In December,  Janu-
 ary   and  February,  the typical  head loss for a 24-hour filter run  was  1.9 m
 (6.2 ft),  1.6 m (5.2  ft)  and 1.6  m (5.2 ft),  respectively,  which was well below
 the  3.0 m (10 ft)  allowable  head  loss.   In the months of April to  November, the
 24-hour filter  head loss generally varied from 2.4 m (8 ft)  to 3.0 m (10 ft).
 On one  occasion,  when the hydraulic loading reached a maximum of 9.3 m/hr
 (3.8 gpm/sq ft) the 24-hour head loss  buildup was  above 3.0 m (10 ft).
                                       39

-------

 C.   Summary of Tertiary  Plant Performance: Plant Reliability and Effluent
      Variability              ~~        ~        ~ - — -- — -

 The  12-month mean total  phosphorus removed by the tertiary treatment plant was
 99 percent   For the year the influent total phosphorus to the tertiary plant
 averaged 4.56 mg/1 and the effluent averaged 0.045 mg/1 of total phosphorus.
 no        ^.averaSe raonthly total Phosphorus concentrations at 7 sampling
 points including raw sewage, secondary effluent, tertiary plant samples  and

  he daily"'!! mo thl^* ^ "" ^^^ in Appendix E   Also tabulate
 the daily and monthly percent removals of total phosphorus by various waste-
 thro^hnMa T^f5-  °fly t0tal Ph°SPhorus concentrations^ April I, 1973
 first sta^e V   !are/  "^ *" FigUI>e ^  The three curves represent the
 totaf'nJ *V       ^     influent total phosphorus, the first-stage effluent
 total phosphorus, and the second-stage effluent total phosphorus






 A summary of daily total  phosphorus  concentrations  in the effluent  from the
 second-stage lime clarifier  and  the  gravity  filters  is shown  in  Figure  5-9
 The probability curves  for total  phosphorus  are based upon 12 months  of daily
 average  data obtained between April  1,  1973  and March 31,  1974.  Each point
 shown represents an aggregation  of up  to  15  daily sample  data points.

 The tertiary plant  effluent  quality  for 12 months is  summarized  in Appendix D
 and probability curves  for turbidity and  suspended solids  concentrations  in
 the second-stage clarifier effluent  and the  filter effluent are  shown in
 ngures  5-10 and 5-11,  respectively.  The mean  suspended  solids  concentration
 in  the tertiary effluent was less  than 1.3 mg/1, the  mean  TOG concentration
 was 16 mg/1,  the average alkalinity  (as CaC03) was 42  mg/1, and  the median
 effluent pH  was  7.5.

 The  coefficient  of variation (% CV) was calculated for the total phosphorus
 removal by various treatment plant units.   The % CV reflects the percentage
 variability  and  is equal to the monthly standard deviation divided by the
 monthly mean.  Lower coefficient values indicate more consistent unit process
 performance.  The percent Coefficient of Variation is shown in Figure 5-12 for
 the  first and second-stage lime clarifiers,  and the  gravity filters,  as  well
as for all three units in series.   The  general interpretation  attached to
                                     40

-------
          TABLE 5-4  TOTAL PHOSPHORUS REMOVAL SUMMARY - APRIL 1973 THRU MARCH 1974

            First Stage Lime Clarifier   Second Stage Lime Clarifier  Gravity Filters
Month
April 1973
May
June
July
August
September
October
November
December
January 1974
February
March
Mean
Influent
(me/I)
\. of s
3.62
3,61
4.96
5.22
4.66
3.83
3.65
4.04
4.13
4.44
6.59
5.98
4.56
Effluent
(mg/1)
0.568
0.318
0.267
0 . 306
0.249
0.269
0.217
0.205
0.270
0.347
0.284
0.279
0.298
Percent
Removal
84.3
91.2
94.6
94.1
94.6
93.0
94.0
94.2
93.5
92.2
95.7
95.3
93.5
Effluent
(mg/D
0.171
0,115
0,097
0.137
0.070
0.046
0,034
0.056
0.046
0,060
0.060
0,105
0.083
Cumul . Percent
Removal
95.3
96.8
98.0
97.4
98.5
98.8
99.1
'98.6
98.9
98.6
99.1
98.2
98.2
Effluent
(mg/1)
0.070
0.060
0.046
0.076
0.041
0.022
0.023
0.032
0.021
0.026
0.043
0.077
0.045
Cumul Per-
cent Removal*
98.1
98.3
99.1
98.5
99.1
99.4
99.4
99.2
99.5
99.4
99.3
98.7
99.0
Percent
Remaining
1.9
1.7
0.9
1.5
0.9
0.6
0.6
0.8
0.5
0.6
0.7
1.3
1.0
Cumulative percent removal as a function of first stage clarifier influent total phosphorus
concentration

-------
   0.4
   0.2
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   .01
     0.01
             I  I
                       1   I     T
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                            I
                                             i   i   n   i   r

                                      SECOND STAGE     •

                                      CLARIFIER EFFLUENT •
                                                             •* FILTER EFFLUENT
                                                    NOTE: EACH POINT REPRESENTS AN AGGREGATION


                                                         OF 10-15 DAILY SAMPLE DATA POINTS.
                                        I
                                               I
               0.2
I   I    I
I
1
                                                                               I
                                                                                     _L_L
                                                                          98
                                                                                      99.9   99.99
                       2    5   10   20     40 50 60     80   90

                         PROBABILITY %,  equal  to  or  less than

FIGURE 5-9.  VARIABILITY OF  TOTAL PHOSPHORUS  IN SECOND STAGE CLARIFIER EFFLUENT AND

             FILTER EFFLUENT, APRIL 1,  1973 TO MARCH 31, 1974.

-------
 10
8.0
7.0
6.0
5.0
4.0

3.0


2.0
|   1.0
2   -8
    .7
    .6
    .4
             i—
                    rr~i
                                                                      '     '   '
                                   SECOND STAGE EFFLUENT
                                                          *•
                                                         •
                                                                    FILTER EFFLUENT
                                                             NOTE -- EACH POINT REPRESENTS AN AGGREGATKJN
                                                                   OF 10-25 DAILY SAMPLE DATA POINTS.
                                    I
                                         I    I   I   I

      0.01
             0.1
                       1
                                                                                       99.9    99.99
                                    10   20  30  40 50 60 70  80   90   95  98  99
                                      PROBABILITY %, equal to or less  than
FIGURE 5-10.  VARIABILITY OF TURBIDITY IN SECOND  STAGE CLARIFIER EFFLUENT AND FILTER EFFLUENT
              APRIL 1,1973  TO  MARCH  31,  1974.

-------
  100


   80


   60





   40
  20
o>

E
   10
Z  °
LU
u


O  4
Q


O



a
Ul
Q

Z
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to

   .8



   .6





   .4
   .2
   .1
C	T
                    T~I   i   i    i   i  i   i  j  i  i—r
                                 CLARIFIER EFFLUENT  •
                                                        FILTER EFFLUENT
                                 NOTE: EACH POINT REPRESENTS AN

                                       AGGREGATION OF 15-40 DAILY

                                       SAMPLE DATA POINTS.
    0.01  0.1
               1   I	L
                               J	L
                                         _L
J	L
            1
                                                  -L
                      2   5  10  20 30   50   70 80  90       99    99.9   99.99


                         PROBABILITY  %, equal to or less than


FIGURE 5-11.  VARIABILITY OF SUSPENDED SOLIDS IN SECOND STAGE CLARIFIER


             EFFLUENT AND FILTER EFFLUENT,  APRIL 1, 1973 TO MARCH 31, 1974.
                                   44

-------
               COEFFICIENT OF VARIATION (% C.V.) =  "^^iT  Xl°°
          50
                                     SECOND STAGE CLARIFIES
           10



            5



            04
co a

£<
                 o
                 <•
                 «
                 TERTIARY TREATMENT PLANT
                       *    *
c
3
_x

3
                         a
                         0)
U

0
                   o
                   Z
«•»  n- c   -Q
*  K! o    v
Q  £ ->   "•
FIGURE 5.-12.  MONTHLY VALUES OF COEFFICIENT OF VARIATION FOR

              TOTAL PHOSPHORUS REMOVAL BY EACH TERTIARY UNIT

              PROCESS AND BY  TERTIARY TREATMENT SYSTEM.
                                45

-------
  % CV  values  is as  follows;

     20                      Highly consistent

     20-39                   Fairly consistent

     40-59                   Inconsistent

     60 and above            Highly variable to unpredictable

The performance of the first-stage lime clarifier was highly consistent in
each month.  The second-stage total phosphorus removal was highly consistent
to fairly consistent except for July and March.  The performance of all three
units in series was highly consistent.  The performance was particularly smooth
in the last seven months due largely to improved process control.
                                   46

-------
                                  SECTION VI

                         SLUDGE TREATMENT AND DISPOSAL
A.  Sludge Handling

Biological sludge from the secondary clarifier was recirculated to the head of
the secondary plant and resettled with raw sludge in the primary sedimentation
basin.  During the initial months of study, the combined primary/secondary
sludge was pumped to the digester, and then to the tertiary thickener.  At
average sludge flows, detention time in the 225 m3 (59,500 gal) thickener was
50 hours.  In an emergency the sludge could be pumped to one of two 284 m3
(75,000 gallon) sludge holding tanks (Figures 4-1 and 4-2, and A-l.)  In June
1973 the digester failed and the combined primary/secondary sludge was re-
routed directly to the tertiary thickener.  Within the next few months piping
modifications were made which permitted the piston pump to replace the centrif-
ugal sludge pump.  Through these changes, the volume of combined primary/sec-
ondary sludge could be calculated from the pumping rate by knowing the length
of the piston stroke, strokes per minute, and pumping duration.

Chemical sludge from the two lime clarifiers normally was pumped to the ter-
tiary thickener by two, variable speed, progressive cavity pumps (Figures 4-2
and A-6),  Alternatively, the chemical sludge could also be pumped directly to
the vacuum filter, to the sludge holding pond, or to the tank truck loading
area.

The tertiary thickener supernatant was returned to the head of the trickling
filter plant via the filter backwash equalization tank and lift station #1
(Figure 4-2).  Normally, the sludge thickener underflow was conditioned with
lime and pumped to the vacuum filter.  However, the thickener underflow could
also be discharged to a tank truck without vacuum filtering or to the sludge
holding pond (Figures 4-2 and A-6).  After vacuum filtration, the sludge cake
was conveyed to a truck for ultimate disposal.  The vacuum filter filtrate,
belt wash water, and vat rinse water were returned to the filter backwash
equalization tank and pumped by lift station #1 to the head of the trickling
filter plant.

B.  Sludge Thickener Influent Characteristics

An average of 13 m /day (3360 gpd) of combined primary-secondary sludge was
pumped to the thickener from November 1973 (when the piston pump was  in-
stalled) through March 1974 (Table 6-1).
                                      47

-------
 TABLE  6-1     BIOLOGICAL  AND CHEMICAL  SLUDGE FLOWS TO TERTIARY SLUDGE
              THICKENER
April  1973
May
June
July
August +
September +
October +
November
December
January 1974 +
February +
March +
Monthly
Average
Combined
Primary/Secondary
Sludge
(gallons/month)
*
*
*
*
*
*
*
101,000
104,000
104,000
94,000
104,000

Volume
(gallons/month)
348,000
588,000
623,000
1,043,000
916,000
777,000
827,000
664,000
1,012,000
1,019,000
718,000
737,000
Chemical
Sludge
Percent from Percent from
1st Stage 2nd Stage
Clarifier Clarifier




77
81
79


51
69
74




23
19
21


49
31
26
101,000
773,000
70
   Sludge volume not directly quantified
   Daily average sludge flow to thickener:
             Primary sludge -                       3,360 gpd
             Chemical sludge - 1st stage clarifier 17,900 gpd
             Chemical sludge - 2nd stag  clarifier  7,500 gpd
30
                                     48

-------
The volume of chemical sludge pumped from the tertiary clarifiers averaged
96 m3/day (25,400 gpd).   This amounted to 2.2 percent of the average daily
wastewater flow.  As seen in Table 6-1, sludge withdrawal from the lime clari-
fiers varied from month to month.   It ranged from 44 m3/day (11,600 gpd)
during plant startup to 127 m3/day (33,600 gpd),   About 70 percent of the total
chemical sludge volume came from the first-stage clarifier; the remainder from
the second stage.  The percentages derived are based on the hours of pumping
and are not adjusted for the pumping speed which was usually,  but not always,
the same for both underflow pumps.

The total sludge flow to the thickener (Table 6-1) averaged 109 m3/day
(28,760 gpd) of which 13 m3/day (3360 gpd) represented combined primary/sec-
ondary sludge, 68 m3/day (17,900 gpd) was from the first-stage lime clarifier
and 28 m3/day (7500 gpd) was from the second-stage clarifier.

Operating experience demonstrated that variations in the volume of primary/sec-
ondary sludge had a much greater effect on thickener performance than varia-
tions in the amounts of chemical sludge.   The. combined primary/secondary sludge
discharged to the thickener averaged 7 to 10 percent solids.

The monthly mean solids concentrations of the chemical sludge ranged from 0.8
to 1.1 percent in the first-stage underflow and from 0.3 to 3.5 percent in the
second stage as shown in Table 6-2.  From 35 to 51 percent of the chemical
sludge was calcium as Ca+2.  In the first stage the calcium concentration was
4 to 5 g/1 and in the second stage 11 to 18 g/1.   The iron  (Fe+3) concentra-
tion in the second-stage underflow was 1 to 2 g/1 or about 10 times the iron
concentration in the first-stage underflow.  Total phosphorus concentration
averaged 0.17 to 0.27 g/1 in the first-stage underflow and about 20 percent of
that in the second-stage underflow.

From a quantitative standpoint, the chemical sludge data in Table 6-2 should be
used cautiously since manually-composited sludge samples are only semi-repre-
sentative of actual chemical sludge.  But from a qualitative standpoint, some
observations can be made.  The second-stage underflow SS were relatively dense
in February and March which was probably due to the heavy calcium carbonate
sludge.  On the other hand, low solids concentrations, as occurred in January,
may have resulted from "coning."  "Coning" occurs when sludge withdrawal, nor-
mally on a periodic pumping basis of 5 minutes per hour, creates a draw-down
profile in the sludge blanket through which clarified wastewater is also drawn
into the suction line of the underflow pump.  "Coning" was eliminated by tem-
porarily speeding up the sludge rake and continuously withdrawing sludge for
about 30 minutes.

C.  Tertiary Thickener Performance

The thickener supernatant was sampled and analyzed for suspended solids, pH,
calcium, and total phosphorus.  These analyses describe the degree of clarifi-
cation provided by the thickener and also point out the composition of a large
portion of wastewater that was returned to the head of the trickling filter
                                      49

-------
                               TABLE   6-2
                 CHEMICAL SLUDGE CHARACTERISTICS*   (mg/1)
1974

January
February
March
First Stage Underflow
Total P SS Ca++
260 8,330
177 9,660 4,940
268 10,900 3,870

Iron**
79
99
156
Second Stage Underflow

January
February
March
Total P SS Ta++
59 3,150
65 35,570 18,240
45 24,730 11,040
Iron**
269
1,580
1,750
 *  Results based on three samples per week except for iron




**  Samples analyzed for iron once per week
                                   50

-------
plant.  The monthly averages for the four parameters are shown in Table 6-3.
The thickener overflow was typically very high in solids, the S^month mean
being 14,8 g/1 with a range of O.ll'g/1 to 28.8 g/1.  The high solids concen-
tration led to plugging of the overflow weir, which in turn led to short-cir-
cuiting.  Withdrawal of sludge for vacuum filtration temporarily improved the
quality of the thickener overflow, but as soon as sludge withdrawal and vac-
uum filtering stopped, the overflow again increased in solids concentration.

Operating experience demonstrated that without the primary/secondary sludge
from the primary clarifier the thickener overflow was relatively low in solids,
and the chemical sludge settled rapidly in the thickener.  This was observed
on several occasions when the combined sludge from the primary clarifier was
not pumped to the thickener and a well-clarified thickener overflow was pro-
duced within a few days.  Jar tests also illustrated the relatively poor set-
tling character of the undigested primary/secondary sludge.  The addition of a
polymer, Betz DK-522, to the undigested primary/secondary sludge appeared- to
improve settling in the thickener.' However, Betz DK-522 was available for
only a brief time because of inadequate supplies.

In practice, the thickener was operated to maximize the underflow solids con-
centration while avoiding septic conditions in the thickened sludge.

D.  Vacuum Filtration and Landfill Disposal

The solids concentration in the underflow was greatest during the first hour of
pumping the underflow to the vacuum filter and varied between 15 percent and
36 percent.  As the sludge continued to be withdrawn for the duration of vac-
uum filter operation, the underflow solids concentration decreased.  When the
underflow concentration had decreased to 5 percent to 8 percent, the vacuum
filter was shut down.

The vacuum filter was operated to produce a sludge cake of at least 30 percent
dry solids without using excess amounts of lime for conditioning.  An operating
procedure was established whereby the filter operation began at the same time
of day, 6 days each week, and remained in operation until the filter cake
solids had decreased to 32 percent.  Through this mode of operation, the filter
cake dry solids averaged 35.7 percent for the reporting period.

The vacuum filter performance for the first year of operation is shown in
Table 6-4.  The yield averaged 49 kg/m2/hr  CIO Ibs/sq,ft/hr) and the sludge
production averaged 690 kg/hr (0.72 tons/hr) on a dry weight basis with lime
addition.  The minimum average yield was 27 kg/m2/hr  (5.6 Ibs/sq.ft/hr) when
lime conditioning was not employed.  The maximum yield with lime addition was
79 kg/m2/hr (16.2 Ibs/sq.ft/hr).  Figure 6-1 shows that the filter yield varied
directly with the feed solids level except for the month of July.  This apparent
inconsistency was a result of increased chemical sludge production resulting in
high initial thickener underflow concentration for the first hour of vacuum
filter operation.  This led to the production of very thick filter cake (1 to
1 1/2 inches compared to normal cake thickness of 3/8 inch) for the first hour
of vacuum filter operation, thus increasing the average filter yield.  In April
and May the combined primary/secondary sludge was digested prior to combining
                                      51

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      TABLE 6-3  TERTIARY  SLUDGE THICKENER OVERFLOW CHARACTERISTICS
Month
August 1973
September
October
November
December
January 1974
February
March
Average *
Average +
Total Phosphorus
(mg/1)
404
1.88
117
392
489
407
414
318
318
363
Suspended Solids
(mg/1)
28.8
.106
8.9
20.3
19.1
10.2
17.4
13.7
14.8
16.9
Calcium
(mg/1)
842
103
374
802
882
598
926
1,570
762
856
pH
9.76
9.62
11.00
9.66
9.45
9.51
9.31
9.20
9.69
9.70
* Average of data from August 1973 through March 1974



+ Average does not include data of September 1973.
                                  52

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                       TABLE 6-4  VACUUM FILTRATION OF COMBINED PRIMARY/SECONDARY AND CHEMICAL  SLUDGES




                                                 APRIL 1973 THRU MARCH 1974
Parameter
Yield - Ibs dry solids/sq ft/hr
Drum Speed - min/rev
Operating Time - hrs
Feed Solids - percent
Cake Solids - percent
Wet Product - tons/hr
Dry Product - tons/hr
Total Wet Yield- tons
(including lime)
Total Dry Yield- tons
(including lime)
Lime Dose- Ibs/ton dry solids
Lime Usage - Ibs
April
1973
5.6
5.29
116.5
15.0
31.9
1.32
0.42
151
49.2
0
0
May
8.4
5.60
71.0
16.0
39.0
1.55
0.64
108
43.5
41
1775
June July October November December January
1974
10.4 14.1 16.2 12.04 11.7 8.33
3.95 2.19 2.76 2.49 2.69 3.81
99.5 149.0 110.0 116.0 102.4 137.1
16.4 13.2 17.8 18.0 16.6 13.3
39.2 38.0 39.1 36.9 35.5 33.0
1.98 2.71 3.10 2.42 2.45 1.67
0.78 1.06 1.32 0.90 0.88 0.56
226 399 333 286 246 224
87.4 155.0 133.0 105.8 87.5 72.7
95 61 34 49 57 76
8275 9510 4000 4300 4950 6800
February March 10-Month
Average +
7.1 6.56 10.04
3.85 3.70 3.60
88.9 85.3 1076.3 *
14.0 11.6 15.2
31.1 33.7 35.7
1.71 1.33 2.02
0.53 0.49 0.76
149 114 2180 *
46.6 39.7 820 *
72 62 61
2825 2350 44,785 *
*  Ten-month total

-------
         E

         O  4
         UJ
         Ul
         CL

         1/1  2
         5
         o

         s  °
        *  15
        £>



        Q  10
                          I    I
           18

        fe?

        crT  16
        a

        O  14
12
10
0

KEY: \
7 (•) No lime conditioner used.
1 1 1 1 1 1 1 1 1 1 |

          -Is
          o«  <   *

0   S-
"-   S
FIGURE 6-1. MONTHLY AVERAGES OF FEED SOLIDS CONCENTRATION,

           FILTER YIELD, AND DRUM SPEED FOR VACUUM FILTRATION OF

           LIME CONDITIONED  COMBINED BIOLOGICAL-CHEMICAL SLUDGE.
                                 54

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with the chemical sludge for thickening and vacuum filtration.  In June 1973
the sludge digester broke down and has not been in operation since that time.
Consequently, the combined primary/secondary biological sludge is not being
digested prior to thickening and vacuum filtration.

As previously stated, the -filter was operated to produce a sludge cake of at
least 30 percent dry solids.  This was to meet a State requirement of a mini-
mum cake solids concentration of 30 percent necessary for the disposal of this
sludge to landfill.  The filter operation produced a sludge cake of 35 percent
solids or better.  For 10 months, the cake mean dry solids content averaged
35.7 percent (Table 6-4), ranging from 31.1 percent to 39.2 percent.  During
April 1973, when no lime conditioning agent was added, the cake solids aver-
aged 31.9 percent.

An average of 74.4 metric tons (82 tons) of sludge (dry weight) was vacuum
filtered each month.  The total production for the year was approximately 893
metric tons  (984 tons) of sludge including 24 metric tons (26 tons) of lime.
Production ranged from 36 metric tons (40 tons) to 141 metric tons (155 tons)
per month.   Increased sludge production in the summer months resulted from
increased wastewater flows and increased chemical dosages.  For example, lime
dosage (CaO) to the first-stage lime clarifier was only 282 mg/1 in February
(43 metric tons sludge produced) but was 340 mg/1 in July (141 metric tons
sludge produced).

Table 6-4 also shows that for 10 months, the total wet sludge production was
1978 metric tons (2,180 tons).  From April 1, 1973 to March 31, 1974 disposal
of this sludge required 350 trips to the sanitary landfill.   Using 6.8 metric
tons (7.5 tons) as a typical truckload, 20 trips were made to the landfill in
February compared with 53 trips in July.

During the 12-month operating period from April 1, 1973 to March 31, 1974, the
vacuum filter produced 893 metric tons (984 tons) of dry solids including 24
metric tons  (26 tons) of hydrated lime. The average filter yield was 49 kg/m2/hr
(10.0 Ibs/sq ft/hr).  The filter sludge cake was typically 35 percent dry sol-
ids.  The dry solids content was at least 30 percent in greater than 95 percent
of the truck loads.  A higher rate of sludge withdrawal from the primary clari-
fier should improve vacuum filtration by eliminating septic  sludge.   The vacuum
filter operation is considered to have been satisfactory; however, the clarity
of the thickener supernatant was•considered marginal.
                                      55

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                                  SECTION VII

                           OPERATION AND MAINTENANCE
A.  Personnel Organization and Tasks

The tertiary plant personnel consisted of 13 people.  There was a plant engineer,
an operator supervisor, a plant foreman, a maintenance and boiler operator, and
nine tertiary plant operators.  Three additional employees operated the trick-
ling filter plant and performed in-plant and up-stream maintenance and repairs.

The tertiary plant maintenance and repair work was performed by the maintenance
person, plant foreman, and City of Ely chief operator.  Sample preparation and
collection was the responsibility of the plant foreman or one; operator-helper.
Safety was the responsibility of project safety officer, plant foreman, and
plant engineer.  Operator supervision, pay records, purchasing, clerical, and
some maintenance were the duties of operator supervisor.  Staff meetings, pro-
cess control, overall supervision, written summaries, and quarterly and annual
reports were the responsibility of the plant engineer.


Day-to-day operation of the tertiary plant was the duty of the EPA operators
and operator-helpers.  Two operators were on hand 24 hours per day, seven days
per week in the tertiary plant.  Each shift included one trained operator and
one operator-helper.

The duties of the shift operators were operating the tertiary' plant, operating
the vacuum filter, and other assigned tasks.  Once each hour an operator col-
lected and composited samples at five locations and recorded totalizer readings,
wet well levels, chemical feed rates, pH meter readings, and solid blanket
levels.  The clarifier mix zone percent solids test was set up on the half-hour
and read on the hour.  Chlorine residuals were determined every two hours.
Every four hours the temperature, gravity filter pressure loss, and effluent
clarity were recorded, and the thickener overflow was sampled.  The operators
adjusted wastewater flow rates, chemical feed rates, recirculation flow, and
sludge withdrawal rates as needed.  Operators inspected lime slakers for exces-
sive lime buildup.

Almost all mechanical and electrical systems were tied into the main control
panel.  When a piece of equipment failed, a light and an annunciator alerted the
operator.  The operator was expected to perform minor repairs as needed.  If
repairs could not be made by the operator, the plant staff was notified.
                                       56

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The operators kept a log of all readings and recordings,  but significant devel-
opments were written in a separate log book.  The written log book included any
change in chemical dosages, equipment breakdowns or repairs, and unusual obser-
vations.

The vacuum filter, while in operation, required full time attention of one
operator.  This operator prepared the lime for conditioning and started the
vacuum filter.  While the filter was operating, samples of the influent and the
dry cake were collected for solids analysis.  The operator saw to it that the
lime additon was correct, that the sludge depth in the vat was maintained, that
the filter cloth was straight, that the sludge cake formed was dry, and that
the sludge cake did not stick to the cloth.   The operator emptied the sludge
into the truck for ultimate disposal at the sanitary landfill.

Additional duties performed by the operators included cleaning the bar screen
and checking the trickling filter plant when the City of Ely operators were off
duty.   Operators inspected the three lift stations and pumps in the vicinity of
the tertiary plant.  In addition, each operator shift was assigned a cleaning
and maintenance schedule.

B.  Plant and Equipment  Problems

    Major Equipment Breakdowns

The major equipment problems  experienced during the first year of  operation of
the Ely plant included the second-stage lime clarifier, the sludge thickener,
the boiler,  and the secondary clarifier.  A description of each failure and the
corrective action  taken  is given below.

         Second-Stage Lime Clarifier  - Both the first  and second-stage lime
clarifiers are equipped  with  a double shaft driver for the impeller and sludge
rake as  shown in  Figure  A-4.  A water-lubricated fiber bearing separates  the
impeller shaft from the  shaft of the  sludge rake.

In October 1973 the fiber bearing developed an unusual noise.  Upon investi-
gating  the cause,  it was determined that a  pipe which  supplied lubricating
water to the  fiber bearing had failed because of inadequate support.  When the
water pipe was repaired, additional pipe supports were used.  However, damage
to the  fiber bearing had resulted, and within five months it  was necessary to
replace the bearing because of excessive wear.

On another occasion a high-pitched noise developed in the second-stage clari-
fier.  Upon investigation, it was determined that two grease  fittings located
near the top of the sludge scraper main shaft had not been properly serviced.
The result was that the  main-shaft bearings were not being lubricated.  Once
the grease fittings were installed, proper  lubrication was applied to the
bearings and the high-pitched noise was no  longer heard.
                                       57

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In March 1974 vibrations developed in the second-stage lime clarifier.   The
vibrations became severe enough to take the clarifier out of operation  and to
drain it for inspection.  Upon inspection, it was found that the mid-joint
fiber bearing was loose and that the sludge agitator paddle had twisted 90
degrees.  With the assistance of a millwright a new fiber bearing was installed
and a new sludge agitator paddle was constructed to replace the one which was
damaged.

         Tertiary Sludge Thickener - On two occasions repairs were required on
the tertiary sludge thickener.  On one occasion unusual noises suddenly devel-
oped in the thickener.  Before the thickener could be inspected, the shaft of
the hydraulic jack snapped.  This jack was used to adjust the operating depth
of the sludge rake.  Extensive repairs to the jack were completed at the fac-
tory and new parts including a new fiber bearing and larger washer, roller
bearing and pin were installed.  It was also necessary to machine a large cyl-
inder and the shaft of the rake mechanism since both these parts had been
scored.

Before two months elapsed, noises from the thickener were again heard.   When
the thickener was drained and inspected the noises were found to be caused by
the bearing assembly which was binding on the thickener bridge.   The resulting
damage, which was a slight scoring of the inside surface of the cylinder sur-
rounding the bearing assembly, was minimal. Adjustments were made to prevent the
bearing assembly from binding on the bridge and no further difficulties were
experienced.

         Boiler - The boiler used to heat the tertiary building was equipped
with an automatic low-water cut-off switch which shuts off the boiler when
water service to the boiler is interrupted.  In November 1973 the automatic cut-
off failed to function which allowed a "dry-firing" of the boiler.   The exces-
sive heat which resulted from insufficient water warped 52 of the heat  exchanger
tubes.  Because it was wintertime, emergency repairs were made immediately.  In
the following March all the damaged boiler tubes were replaced,

         Secondary Clarifier - In the biological treatment plant, the scum rake
in the secondary clarifier fell off its track which caused damage to the scum
rake and bull gear.  When repairs were being made, cracks in the clarifier floor
were found.  The cracked protion of the clarifier floor was repaired, the scum
rake repaired, and a new bull gear was installed.

         Comminutor and motor - The communitor which had been added to  the head
of the secondary plant when the tertiary plant was constructed was repaired at
a cost of almost $2,000.  After only two years of operation it became necessary
to replace all the cutting teeth and shear bars.  The comminutor motor also
burned out and had to be replaced.  While the unit was out of operation for re-
pair, a rag problem developed which resulted in repeated plugging of the thick-
ener underflow pumps.  This problem was temporarily circumvented by removing rag
debris by three bar screens located in series in the grit chamber of the second-
ary plant.
                                      58

-------
         Sludge pumps - The Moyno pumps, which removed thickened sludge from
the tertiary thickener, regularly became plugged with rags.  This problem was
aggravated when the comminutor was out of service.   The rag problem increased
the wearing rate of the stators.  The stators on all four sludge pumps were
excessively worn within 1 1/2 years of operation and the installation of new
stators was required.

         Polymer Mixer - For three months a polymer; Betz 1150, was mixed auto-
matical ly~with~a~liiechahical mixer.  The mixer required excessive cleaning and
maintenance because the dry polymer feed opening, which was installed in the
mixer, regularly became plugged by wetted polymer particles.  After using the
mixer for three months, the practice was discontinued.    Thereafter,  the
polymer was periodically batch-mixed in a day tank, which resulted in an effi-
cient, low-maintenance, operation.

         Miscellaneous repairs - The minor repairs required included the
following:

(1)  The carbon dioxide primary regulator leaked and had to be tightened with
new bolts.

(2)  The wear plate on the vacuum filter had to be replaced frequently.

(3)  Factory repair of the chlorine detector and the torque overload control
on the first-stage lime clarifier sludge scraper was required.

    Design Considerations

Hindsight demonstrates that many changes and additions could have been designed
into the tertiary wastewater plant to improve plant operation  and reliability
of equipment.  During the first one and one-half years of operation, a number
of process modifications and safety improvements were made.  Among them are the
following:

(1)  C02 feed pipe - During the first months of operation the  wastewater influ-
ent pipe to the second-stage lime clarifier became completely  plugged with
calcium carbonate.  To correct  the situation, the CO 2 line, which had been
feeding into the influent pipe, was moved so that CO- could be fed directly to
the mix zone of the second stage.  This eliminated tne buildup of CaC03 in the
pipe between the first and second-stage lime clarifiers.

(2)  Boiler - Two smaller boilers should have been provided instead of one
large boiler for heating the Ely plant.  The winter temperature  in Ely, Minne-
sota can reach -40°C  (~40°F) or lower,  and a boiler failure in such weather
could cause extensive damage to the tertiary plant.  Recognizing this risk,
turbine heaters and electric heaters were purchased in October 1973 for emer-
gency heating.  On November 15  the boiler failed in moderate subfreezing wea-
ther, but the emergency heaters provided sufficient heat.  Had the  temperature
been extreme, the turbine and electric  heaters would probably  have been inade-
quate.  In such a situation and with a  two boiler arrangement, one boiler could
prevent the tertiary plant from freezing if the other boiler had failed.
                                      59

-------
 (3)   Vacuum filter lime  conditioning  agent  - No provisions ?iad been made  in  the
 original  design for feeding  a  sludge  conditioning  agent to the vacuum  filter.
 When  it was determined lime  conditioning was necessary, a day tank, pump,
 mixer, and related equipment were installed in the vacuum filter room  as  an
 interim lime-feeding system.   For the permanent system the lime slaker dis-
 charge piping  was  modified to  allow slaked  lime to be pumped to the day tank
 in the vacuum  filter room.

 (4)   Ventilation in the  VF room - No  exhaust fan had been included in  the de-
 sign  of the filter room.  A  large stand-up  fan, exhausting to the main plant,
 was added and  provided very  good ventilation.

 (5)   Glass piping  -  Glass piping which was  used to feed sulfuric acid  and fer-
 ric chloride proved to be both unreliable and dangerous.  Occasionally a  length
 of glass  pipe  would break and  fall to the ground, or a glass valve would break
 off while being turned.  Maintenance  personnel could not work near the glass
 piping for fear of breaking it.  As a result, sulfuric acid piping was replaced
 with  CPVC piping and ferric chloride  lines  were replaced with CPVC tubing.

 (6)   Storage -  Two new storage areas  were developed.  (a)  A metal shed was
 constructed to  store spare parts, tubing, piping, tanks, welders, fittings,  etc.
 (b) The carbon  storage room was divided to  create a storage area for laboratory
 chemicals  in one section and powdered carbon in the other.

 (7)   Water hammer  -  In general, tertiary plant effluent was used for the
 757 m-Vday (200,000  gpd) process water required in the tertiary plant.  City
 water was  used  for process water only one percent of the time.   On those occa-
 sions, however,  a  water hammer was created  that damaged hot water heaters in
 the vicinity of the  Ely plant.   A pressure  relief valve was put ahead  of the
 break tank to protect against the water hammer.  The relief valve ended further
 damage to  the hot  water heaters, although fluctuations in water pressure con-
 tinued when  the  city  supply was used for tertiary process water.

 (8)  Additional  modifications were made or were suggested to improve operation
 of the Ely plant.   (a)  The plant effluent  totalizer range was increased from
 11,356 m3/day  (3.0 mgd) to 18,925 m3/day (5.0 mgd)  in order to record  flows
 that bypass  the  tertiary plant.  (b)   A wet well level indicator was installed
 in the operator  control room.  (c)   Controls to activate the sludge hopper
 doors were repositioned to improve plant safety and maintenance.   (d)   Individ-
ual underflow metering devices  for each lime clarifier are recommended to re-
place the  combined underflow totalizer.   (e) Chemical feed pumps  should be con-
nected to  the emergency power source.   (f)   The capacity of each of the two
effluent recycle pumps should be greater,  since one pump was inadequate about
half the time.    (g)  The probe  for the high-level alarm on the CaO bins was too
short to provide sufficient warning when filling the CaO bins.   The probe has
been  lengthened.   (h)  Tertiary plant effluent water is  now used  for all non-
potable purposes except polymer makeup.   This has resulted in a considerable
savings in costs.


 Despite these  design and equipment difficulties, the processes and equipment
 performed  well  enough to meet the design effluent total phosphorus requirements.
                                      60

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C.  Maintenance Requirements

Routine maintenance duties were performed by the City of Ely operators,  EPA
operators, and EPA day shift personnel.   The City of Ely operators shoveled
snow in the winter, cut the grass in the summer, and kept the wastewater plant
grounds orderly.  The city operators cleaned the bar screen and grit chamber,
cleaned the trickling filter distributors and moving parts, inspected and re-
paired the secondary plant pumps, and lubricated all secondary plant pumps and
mechanical equipment.  The city operators assisted the EPA personnel with the
tertiary plant maintenance, thereby familiarizing themselves with the tertiary
plant equipment.

Maintenance of the trickling filter plant and the tertiary plant was the re-
sponsibility of the day shift personnel.  Each week the plant engineer compiled
a list of maintenance problems.  The operator supervisor, the foreman, the
maintenance man, and the City of Ely chief operator saw to it that required
maintenance was performed.  The routine maintenance duties included cleaning
out plugged sludge pumps; lubricating equipment; ordering spare parts; repair-
ing or cleaning hoses, pipes, tanks, fittings, valves, stand pipes, and rota-
meters; and performing some custodial duties.  The day shift personnel oper-
ated a welder,  torch, grinder, compressor and other equipment needed in making
repairs.  The vacuum filter required maintenance which included lubrication,
sewing and glueing replacement filter cloths, replacing filter springs, chang-
ing the wear plate, removing lime scale from the filter grids and drum, and
repainting the  drum.  The filter cloth was changed three times in the initial
five months; however, the most recent filter cloths lasted six and seven months,
respectively.

The shift operators contended with high maintenance items as the lime slakers,
chemical feed pumps, and underflow pumps.  The operators cleaned around the
slaker paddle shaft and weigh belt, and checked the lime paste consistency
every four hours.  The lime feed piping, particularly the valves and the ejec-
tors, became plugged or coated with lime and had to be disassembled and cleaned.
The operators replaced valves, gaskets, diaphragms, etc. in the chemical feed
pumps as the parts wore out.  Operators unplugged the thickener underflow pumps
that regularly  bound with rags or heavy sludge.  The chemical sludge underflow
pumps on occasion required both unplugging and replacement of shear pins.

Preventive maintenance performed by the operators involved  inspecting the  pack-
age lift stations, lubricating some equipment, checking and sometimes bleeding
the influent pumps and effluent recycle pumps, inspecting  the powdered carbon
unit, testing for chlorine leaks, observing the temperature of the chlorine
room and the emergency generator room, and checking the boiler.

The custodial duties of  the operators were mopping halls and floors, hosing
down the floors in the main process area, the chemical rooms, the dry wells,
and the gravity filter pit, cleaning the vacuum filter room and equipment,
cleaning the truck room, and general housekeeping.

The distribution  of  operation  and maintenance duties  is  shown in Table  7-1.
                                       61

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K)
                               TABLE 7-1  MANPOWER REQUIREMENTS FOR ELY AWT PLANT
MAN -YEARS/ YEAR

Unit Process Admins.
Grit Chamber and Comminutor
Secondary Treatment **
First-stage lime clarifier
Second-stage lime clarifier
Gravity filters
Other process equipment
Lime storage and feeding
Ferric chloride, sulfuric acid, polymer
Carbon dioxide, chlorine
Underflow pumps
Sludge Thickener
Vacuum filter
Sludge disposal
Tertiary Building Systems
Emergency Generator
Plant Grounds
Sample collection and preparation
Laboratory analysis .60
Administration 1 . 20
Process control and data analysis .60
Reports .40

Operation
.29
.25
.77
.78
.09
1.00
.18
.40
.47
.08
.06
1.15
.29








Prev.
Maint.
.02
.11
.06
.06
.05
,20
.25
.15
.14
.02
.03
,06
.02
.35
.08

.04
.15



Corr.
Maint .
.04
.54
.02
.11
.06
.20
.22
.05
.04
.90
,11
.09
,04
.15
.02
.20
.14
.15



Sampling
§ Analysis Custodial Total
.35
.90
.85
.95
.20
1.40
.65
.60
.65
1.00
.20
1.30
.35
1.15 1.65
.10
.30 .50
.92 1.10
2,80 3.70
1.20
.60
.40
    Totals
                                  2.80
5.81
1.79
3.08
3.72
1.45
        *
       **
1 man-year = 2080 hours
primary settler, trickling filter, and secondary settler
18.6

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    Maintenance - Electrical, Boiler, and Instruments

The duties of the designated maintenance man involved electrical work, instru-
mentation, heating, air-conditioning, and ventilation.  Besides routine duties,
the maintenance man installed electrical conduit and did some welding.  The
maintenance man was assisted by other personnel as needed.

Electrical work included checking and greasing motors in both the trickling
filter plant and tertiary plant, along with maintaining motor controllers, the
diesel emergency generator, and the gravity filter backwash cycle and valve
sequence.

Any instrumentation such as calibrating pH meters, the flow proportional sys-
tem, and flow meters was the responsibility of the maintenance man.

During the heating season the boiler was regularly inspected for C02, smoke
and draft.  Every two weeks low and high water cut-offs were tested.  Filters
to the air exchangers, the boiler air supply, and the air-conditioning system
were changed as needed.  Steam traps were inspected and cleaned every other
season.  The maintenance man was expected to perform his duties without spe-
cific supervision.

    Safety

The purpose of the safety program at the tertiary wastewater plant was to
create safety awareness, maintain a  safe work area, provide safety training,
and seek participation by all personnel in  safety discussions and in  detection
of hazards.

A safety committee, including the tertiary  plant foreman, was established and
acted to bring all work areas,  including the tertiary plant building, up  to at
least OSHA standards.  As part  of directing the safety program,  the safety
committee inspected work areas  for hazards, put up posters concerning safety,
organized first  aid courses, encouraged good housekeeping to prevent  accidents,
and made  recommendations to  eliminate hazards  in the working environment.

In order  to reduce safety hazards in the tertiary plant,  the following actions
were  taken.  An  access platform was  constructed around  the vacuum filter,
safety showers and eye washes were installed in the  laboratory  and next to the
sulfuric  acid pump; glass piping for sulfuric  acid and  ferric chloride was re-
placed with CPVC piping; alarms for  evacuation were  mounted at  five locations
in  the tertiary  plant building; defective  guards on  machinery were replaced or
repaired; steel  mesh and non-slip tape were attached to  slippery surfaces; and
a railing was  constructed around a drywell manhole as a  substitute  for a  warn-
ing  chain.  Life jackets,  safety lines,  and harnesses were purchased  for  work-
ing  above clarifiers.  Rubber  suits  and  an acid resistant hood  were obtained
for  handling  sulfuric acid.  Hard hats  and ear plugs were also  purchased. The
wearing  of hard  hats was required for  anyone  in  the  process area of  the ter-
tiary plant.
                                       63

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The safety committee as a group Inspected the tertiary plant periodically;
however, one safety committee member checked for hazards in the plant each
week.  The weekly inspection included checking fire extinguishers, safety
showers, and the self-contained breathing apparatus.  On one inspection dead
flies were discovered blocking the air-flow to the mask of the self-contained
breathing apparatus.  The plant was also inspected for safety deficiencies by
three safety experts from an insurance company.

Safety skills and awareness of personnel have been enhanced by various train-
ing courses and lectures.   Two members of the safety committee attended one-
week courses in safety.  Six of the plant personnel have received first aid
training at a 14-hour course sponsored by the Red Cross.  Plant personnel par-
ticipated in a seminar on chlorine safety.   Listening to tapes on safety,
safety meetings, evacuation drills and the distribution of memos and pamphlets
on safety were also part of the safety program.
                                     64

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                                 SECTION VIII

                      COSTS OF OPERATION AND MAINTENANCE


The costs required to operate the plant from April 1,  1973 through March 31,
1974 totaled $389,107.64.  During this period  1.6 x 10& m3 (427.7 million
gallons) of wastewater were treated at a cost  of $0.24/m3 ($0.91/1000 gallons).
The 12-months1 operating costs and the percentages for 27 categories are shown
in Table 8-1.  The unit chemical costs and power costs are shown in Table 8-2.

The relative costs for personnel, chemicals, utilities, miscellaneous, and
equipment operation and repair are shown in Figure F-l.  The five principal
cost categories are subdivided in Figures F-2  through F-6.  The operational
cost breakdowns which are shown in Appendix F  are based on the cost information
in Table 8-1.

Figure F-l points out that more than 60 percent of the operational costs were
for operating personnel.  This reflects the need for a skilled staff.  Chemical
costs, including shipping, amounted to  15 percent of total operational costs
or $58,000 per year.  The cost of shipping in chemicals was high because of the
distance from chemical suppliers.  Chemical usage, which was confined almost
entirely to  the tertiary operation, was greater in the summer months while util-
ity costs, particularly fuel oil costs, were highest in the winter months.
Utility costs were 9.7 percent of total operational costs (Figure F-4).  Miscel-
laneous supplies represented 5.8 percent of total costs (Figure F-5), and the
cost to operate and repair plant and equipment was 8.3 percent (Figure F-6).

Personnel costs are apportioned in Figure F-2.  Operator salaries amounted to
about one-half of personnel costs and provided for two operators in  the  terti-
ary plant 24 hours per day, seven days  per week.  Two operators were required
at all  times to ensure high performance of the wastewater treatment process and
for their own safety.  Laboratory personnel performed a very large number of
analyses during the  12-month period of  tertiary plant operation.  The wastewater
stream  was  sampled daily at eight locations and the underflow streams were sam-
pled several times per week.  The wastewater samples were tested  for more than
a dozen parameters;  some daily,  some  three  times  a week,  and some weekly.  Main-
tenance tasks were performed by  the foreman, supervisor,  and operators  as well
as  the  maintenance-boiler  man and assistant.  The maintenance-boiler assistant,
along with  the foreman,  collected and prepared samples  for  the laboratory.

Figure  F-3  indicates  that 87 percent  of the cost  of chemicals was  expended  for
 lime, carbon dioxide,  and  ferric  chloride.  The  category., "Other  Chemicals/'
 included chiefly  the cost  of powdered  carbon.  During  five  months  of operation
                                      65

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                             TABLE 8-1
OPERATION AND MAINTENANCE COSTS FOR ELY WASTEWATER TREATMENT PLANT
                     APRIL 1973 THRU MARCH 1974
Category
Personnel (December 1974 waee
Operators
Maintenance S, Boiler
Foreman, Supervisor
Engineer
Laboratory
Accounting
Subtotal
Chemicals
CaO
Cl2
C02+Rental
FeCl3
H2S04
Poly
Other chemicals
Subtotal
Utilities
Electricity
Water
Heating-fuel oil, propane
Telephone
Subtotal
Supplies
Laboratory
Sampling
Custodial
Grease § oil
Subtotal
Equipment Operation £ Repair
Replacement S, spare parts
Misc. repair § maintenance
Equip, repairs £ maintenance
New Equipment - Structures
Safety Equipment
Sludge Truck 0£M
Subtotal
TOTAL COSTS
12 -month
Costs
rates)
116,215.34
30,608.67
30,291.81
14,696.00
45,000.00
1,678.00
238,489.82
15,406.04
1,655.25
18,606.51
16,459.39
2,815.89
1,931.96
1,195.03
58,070.07
20,088.54
440.47
15,653.77
1,553.50
37,736.28
20,450.00
1,743.92
232.76
145.58
22,572.26
16,497.36
7,777.67
3,702.29
2,517.68
906.44
837.77
32,239.21
389,107.64
Percent of
Category
48.7
12.8
12.7
6.2
18.9
.7
100.0
26.5-
2.9
32.1
28.3
4.8
3.3
2.1
100.0
53.2
1.2
41.5
4.1
100.0
90.6
7.7
1.0
.7
100.0
51.2
24.1
11.5
7.8
2.8
2.6
100.0
Percent Unit
of Total 
-------
TABLE 8-2  UNIT COSTS OF CHEMICALS AND POWER FOR ELY AWT PLANT OPERATION
Chemical Costs
          Lime:                 Low -  $25.25 per ton
                                High - $32.77 per ton
                                Freight  - included

          Ferric chloride:      Low - $80.00 per ton
                                High - $90.00 per ton
                                Freight  - $40.08 per ton

          Sulfuric  acid:        Low - $45.15 per ton
                                High - $50.90 per ton
                                Freight  - included

          Carbon dioxide:       Low - $65.00 per ton
                                High  - $75.00 per ton
                                Freight  - included

          Polymer  (Betz 1150):  Low  - $2.38 per Ib.
                                High  -  $3.32 per  Ib.
                                Freight  -  included
 Power Costs
           Electricity:          Low -  2.05<^/kWh
                                 High - 2.06<£/kWh
           #2 fuel oil:          Low - 23.6^/gal
                                 High - 29.95*/gal

           Propane:              Low - 25.9
-------
 ferric chloride was  shipped  in  drums  rather  than by  tank  truck, which  signif-

 clTiy^nnnnaSed  ^  C°St °£ ferriC  chloride"  The  carbon dioxide  costs  in-
 cluded $3,000  per  year rental of  a C02 refrigerator-storage unit.

 The  cost  of water  as shown in Figure  F-4 was kept very low by utilizing ter-
 water  Pl3nt efflU6nt f°r &11 tertiary P^nt processes except polymer make-up


 In Figure F-5,  laboratory expenses, excluding laboratory personnel  costs
 accounted for  almost all miscellaneous costs.  Laboratory expenses were large
 because considerable analytical work  was necessary for research and quality
 control in the  tertiary plant.

 Equipment replacement  and spare parts totaled 51 percent of the total main-
 tenance costs as shown in Figure F-6.  A large spare parts inventory was
 obtained to allow repairs to be made promptly and prevent downtime caused by
 a slow delivery and/or shortage of parts.  Some equipment required periodic
 replacement of parts such as the underflow pumps and chemical  feed pumps   The
plant staff minimized repair and maintenance costs by making the repairs them-
 selves.  Repair costs were increased due to extensive repairs  needed in the
 20-year-old trickling filter plant.   New equipment purchases included emergency
heaters, a storage shed, and a pump with a motor to route slaked lime to the
vacuum filter room.
                                     68

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                                 SECTION IX

                                 REFERENCES


1.   "Shagawa Lake Project:   Lake Restoration by Nutrient Removal from Waste-
    water Effluent," Environmental Protection Agency, Report No. EPA R3-73-
    026, January, 1973.

2   Fair, G.M., Geyer, J.C., and Okun, D.A., Water Purification and Waste-
    water Treatment and Disposal, John Wiley § Sons, Inc., 1968, pg. 30-11.

3.   IBID, pg. 29-22.

4.   Sawyer, C.N., and McCarty, P.L., Chemistry for Sanitary Engineers, McGraw-
    Hill, Inc., 1967, pg. 292.

5.   IBID, pg. 297.
                                       69

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                  APPENDICES






                  APPENDIX A








TREATMENT PLANT LAYOUT PLANS AND DESIGN CRITERIA
                     70

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                                                    INFLUENT WET
                                                           WELL
                                            INFLUENT PUMPS   _j
                                                             CHLORINE
                                                             CONTACT
                                                             CHAMBER
                                                                              SLUDGE DIGESTER
                                                                                  ^	-X
                                                                                  TRICKLING
           EFFLUENT   i
      METERING STATION
SLUDGE HOLDING POND |
                                                    Laboratory!  ?_o>
                                                         II  In U
                                                                                          ,   PRIMARY
                                                                                          11  CLARIFIER
                               kludge Thickener
                              Filter Backwash Equalization Tank     j
                               (°) PACKAGE Lin
                                    STA. NO. 1                       i
                               SLUDGE
                               HOLDING
                                 POND
                                  DRAIN
                                     Filter Backwash
                                                                             SLUDGE
                                                                            HOLDING
                                                                             TANK
                                            LIFT STA. NO. 2
                                                                                                           =40 feet
STINKY DITCH
        LEGEND
      	 PROCESS
      	 BYPASS
                Flow Intercepting
                       Structure
                                                                                             COMMINUTER
                                                                                                    PACKAGE LIFT
                                                                                                   STATION NO.  3
••	*- Influent Sewer



^-—Syphon

      Plant Influent
          APPENDIX A, FIGURE A-1.  WASTEWATER TREATMENT PLANT LAYOUT PLAN

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                                                     14" Reactivates
                      14" Overflow to Influent Wet Well      No. 1 Bypass  Magnetic Flow Meter
                                                                                             14" Overflow to
                                                                                             Influent Wet Well
                                                                                                ^INFLUENT PUMPING STATION
        EFFLUENT RESERVOIR
24" Effluent to Metering
     & Sampling Station s/,~2~
                    • i  'i'
  24" Tertiary Bypass _{.,  fl
14" Effluent Reservoir        >
                    M '
   14" Gravity Filter Bypass
8" Effluent Reservoir Drain-f,
                                                               16" Reactiva
                                                               No. 2 Bypass
                                                 16" Reactivator
                                                 No. 2 Effluent
                    Flow Splitter Box
                   Gravity Filter Units

                               1 1
                                                                                                                             .INFLUENT MANHOLE
     'condary  Effluent



|jJ«-24" Tertiary Bypass
  APPENDIX A; FIGURE A-2.   TERTIARY PLANT  LAYOUT PLAN SHOWING WASTEWATER PIPING

-------
    VARIABLE SPEED
    SLUDGE  SCRAPER  DRIVE
  COLLECTOR FLUME
 TREATED WATER \
     OUTLET
   VARIABLE SPEED
   RECIRCULATOR  DRIVE
   DRAFT TUBE
                                                            IPOLYMER FJJD
SLOW MIXING  AND
FLOC FORMATION
   SCRAPER ARMS
SLUDGE COLLECTOR PIT
         6" SLUDGE DRAWOFF
      »AiviMr       WASTEWATER
RAPID MIXING       INFLUENT
AND  RECIRCULATION  'pNpFELUENT
IMPELLER
SLUDGE  AGITATOR PADDLE

3" CLEANOUT
    APPENDIX  A,  FIGURE  A-3.   FIRST STAGE  LIME CLARIFIER
                                    73

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     VARIABLE  SPEED
     SLUDGE SCRAPER DRIVE

    COLLECTOR FLUME
  TREATED WATER
      OUTLET
     VARIABLE SPEED
     RECIRCULATOR DRIVE
                                           DISSOLVED C02  FEIED]
SLOW MIXING AND
FLOC FORMATION

  SCRAPER  ARMS

SLUDGE COLLECTOR PIT
        6" SLUDGE DRAWOFF
RAPID MIXING       WASTEWATER
AND RECIRCULATION  INFLUENT
IMPELLER           P'PE

SLUDGE  AGITATOR PADDLE

3"  CLEANOUT
  APPENDIX  A,  FIGURE  A-4. SECOND STAGE LIME CLARIFIER
                                  74

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                                     BACKWASH
                                     COMPARTMENT
             GRAVITY FILTER
             EFFLUENT
          FILTER
      COMPARTMENT
24" THICK ANTHRACIH

        BACKWASH
           PIPE
                                                            GRAVITY FILTER
                                                            INFLUENT
                                                            FROM FLOW
                                                            SPLITTER BOX
VALVE U

  VALVE  A
                                                                VALVE C
         APPENDIX A, FIGURE A-5. GRAVITY FILTER  UNIT
                                     75

-------
6" Sludge'to Sludge

  Holding Pond
   4" Sludge Pump
   Discharge
                                                        6" Underflow
                                                        Pump Discharge
 4" Sludge to Truck
 Loading  jj      I
 •4" Vacuum Vent  fH ™l/s.
 -Vacuum Filter     | fj    /
    Sludge to Vacuum FilterA
         U      * •'
Sludge Conveyor
   •      W
•Sludge  Hopper    ( «
 with Hydraulic Gatesfe—
                                          <;   -»•• Sludge     \  4" Filtrate to Backwash
                                          I    Thickener     \JEqualization Tank
                                           I   Overflow        4" Filtrate tn Clurlno TkirLo^ar
                                           \                          -~	"- 		
                                            4" Digested Sludge
                                             to Sludge Thickener
              APPENDIX A, FIGURE A-6.  TERTIARY PLANT  PLAN  SHOWING SLUDGE PIPING

-------
                                  APPENDIX A

                                   Table A-l


                               DESIGN CRITERIA
1.   Grit Chambers (2)
       Velocity Control
       Length
       Width
       Depth

2.   Comminuter
       Design Flow
       Peak Flow

3.   Primary Clarifier
       Diameter
       Sidewall Depth
       Volume
       Detention Time
         @ 1893 m3/day (0.5 mgd)
         § 3785 m3/day (1.0 mgd)
         @ 5678 m3/day (1.5 mgd)
       Overflow Rate
         @ 1893 m3/day (0.5 mgd)
         @ 3785 m3/day (1.0 mgd)
         @ 5678 m3/day (1.5 mgd)
       Weir Length
       Weir Overflow Rate @ 5678 m3/day
                               (1.5 mgd)

4.   Trickling Filter
       Diameter
       Rock Depth
       No. of Distributor Arms
       Surface Area
       Hydraulic Loading @ 5678 m3/day
                              (1.5 mgd)

5.   Secondary Clarifier
       Diameter
       Sidewall Depth
       Volume
       Detention Time
         § 1893 m3/day (0.5 mgd)
         @ 3785 m3/day (1.0 mgd)
         @ 5678 m3/day (1.5 mgd)
Proportional Weir
   10 m (32'-6")
   0.9 m (3'-0")
   1.2 m (4'-0")
   5678 m3/day (1.5 mgd)
   28,387 m3/day (7.5 mgd)
   15.2 m (50')
   2.4 m (7'-10")
   473 m3 (16,700 cf)

   6 hrs.
   3 hrs.
   2 hrs.

   10 m/day  (255 gpd/sq ft)
   21 m/day  (510 gpd/sq ft)
   31 m/day  (765 gpd/sq ft)
   44.5 m (146')
   128 m2/day  (10,270 gpd/lf)
   18.3 m  (60')
   1.8 m (61)
   4
   263 m2  (2830 sq ft)
   21.6 m/day  (530 gpd/sq ft)
   15.2 m  (50'-0")
   2.1 m  (6'-10")
   417 m3  (14,700  cf)

   5.3 hrs.
   2.65 hrs.
   1.77 hrs.
                                     77

-------
         Overflow Rate
           § 1893 m3/day (0,5 mgd)            10,4 m/day  (255 gpd/sq ft)
           8 3785 m3/day (1.0 mgd)            20.8 m/day  (510 gpd/sq ft)
           § 5678 nrVday (1,5 ragd)            31,2 m/day  (765 gpd/sq ft)
         Weir Length                          44 <8 m (U7 .)
         Weir Overflow Rate 8 5678 m3/day     128 m2/day  (10,270 gpd/lf)
                                (1.5 mgd)
 6.   Chlorine Contact Chamber
         Length                               12.8 m (42')
         Width                                4.8 m (16')
         DePth                                1.5 m (5')
         Volume                               95.12 m3  (3360 cf)
         Detention Time
           §  1893 m3/day (0.5 mgd)             72 min.
           §  3785 m3/day (1.0 mgd)             36 min.
           6  5678 m3/day (1.5 mgd)             24 min.

 7.   Solids Contact Unit No.  1 (Graver  Reactivator No.  1)
         Diameter                             16.76 m  (55')
         Sidewall  Depth                       5.94 m (19'-6")
         Volume
          Mixing  Zone                         27.74 m3  (980  cf)
          Flocculation Zone                   92.0 m3  (3250  cf)
          Clarifier  Zone                      1135.2 m3  (40,100  cf)
        Detention Time
          @ 5678 m3/day (1.5  mgd)
                     (Design Flow)             5.3  hrs.
          8 11,355 m3/day  (3.0 mgd)
           (Hydraulic  Design  Flow)            2.65  hrs.

8.  Solids Contact Unit No. 2 (Graver Reactivator  No. 2)
        Diameter                              16>76 m (551)
        Sidewall Depth                        5  03 m (16,_6n)
        Volume
          Mixing Zone                         23.21 m3 (820 cf)
          Flocculation Zone                   77>28 m3  (273Q c£)
          Clarifier Zone                      952.63 m3  (33,,650 cf)
        Detention Time
          § 5678 m3/day (1.5 mgd)
                    (Design Flow)             4.45 hrs.
          @ 11,355 m3/day (3.0 mgd)          2.23 hrs.
).  Automatic Gravity Filters (Graver Mono-Scour Filters)
        Number                               4
        Diameter                             3.7 m (12.)
        Unit  Height                           4.9 m (16t)
        Filter Media  Depths
         Anthracite                          0.61  m (24")
         Sand                               0.30  m (12")
       Surface Area                          10.5  m2 (113  sq ft)
                                  78

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10.
11.
12.
    Design Flow

    Max, Peak Flow

    Average  Backwash  Flow

    Backwash Air Compressor
       e  0,031 Pa  (4.5 psi)
       Motor  (.1800 rpm)
    Backwash Chamber  Volume
Sludge Digester
    Diameter
    Sidewall Depth
    Volume
    Heat Exchange
    Gas  Compressor  @0.055  Pa (8.0 psi)

Sludge Thickener  (Graver Rota-Rake)
    Diameter
    Sidewall Depth
    Volume
    Design Flow
    Detention Time  §0-0037 m3/s (60 gpm)

Vacuum Filter
    Diameter
    Face Width
    Surface  Area
    Drum Speed
    Vacuum Pump @ 0.508
       Motor  (1750  rpm)
    Filtrate Pump  @ 11
       Motor  (1150  rpm)
   0.0164  m3/s (260 gpm)  per filter
   0.00156 m/s (2.3 gpm/sq ft)
   0.0249  m3/s (396 gpm)  per filter
   0.0023  m/s (3,5 gpm/sq ft)
   0.11  m3/s (1690 gpm)
   0,0101  m/s (15 gpm/sq ft)

   0.26  m3/s (550 cfm)
   15 hp
   26.3  m3 (930 cf)

   7.3 m (24')
   4.51  m  (15')
   205.2 m3 (7250 cf)
   300,000 BTU hr.
   73.6  m3/hr (2600 cfh)


   7.9 m (26')
   5.029 m fl6'-6")
   225.34  m3 (7960 cf)
                                              0.0037 m3/s
                                              16.5 hrs.
               (60 gpm)
                            m  (20")Hg

                            ,58 m  (38' TDH)
13.
   Pumps                No.     HP.
   Sewage
   Recirculation         2    7.5
   Influent              2   30.0
   Effluent Water        2   15.0
   Tert. Serv. Water     2   20.0
   Sec,  Serv.  Water      1    1,5
   Lift Sta. No, 1       2   10
   Lift Sta. No. 2       25
   Lift Sta, No. 3       23
   Sludge
   Primary (PD2)         1    2
   Secondary             1    2
   Digested              1    2
   Recirculation (HE3)   1
   Underflow             2    7.5
   Transfer              2    7.5
   1.8 m (61)
   2.4 m (8')
   13.93 m2 (150 sq ft)
   0.14 to 0.94 rpm
   0.2595 m3/s (550 cfm)
   30 hp
   0.0075 m3/s (120 gpm)
   3 hp
RPM      TDH  ft.   Design Flow  (gpm)
                                            1150
                                            1150
                                            3500
                                            1750

                                            1150
                                            1150
                                            1150

                                              48.6
                                            1150
                                            1150
            37
            65
           170
           120

            55
            40
            30

            23
            37
            37
            25
 500
1100
 150
 300

 200
 100
 100

  85
  50
  50
 150
                                        Var.  Speed (84-420)
                                        Var.  Speed (84-420)
TDH
- Total Dynamic Head  2Positive Displacement    3Heat Exchanger
                                       79

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   C.  Sump Pumps
       Influent
          Drywell
       Effluent
          Drywell
       Underflow
          Drywell
       Lift Sta. No,
       Lift Sta. No.
       Lift Sta. No.
                            No,
                 RPM   TDH ft,  Design Flow  (gpm)
2
1
1
1
 1
1/3
1/3
1/3
14.   Chemical Feed Systems
   A.   Chlorine
         Storage Units
         Tertiary Chlorinator
           Rotameter-Tertiary
           Adjustable Range
             @ 5678 m3/day (1.5 mgd)
         Secondary Chlorinator
           Rotameter-Secondary
           Adjustable Range
             @ 5678 m3/day (1.5 mgd)
   B.   Carbon Dioxide
         Storage Unit (Cardox Rental)
         Feeder
         Rotameter
         Adjustable Range
             @ 5678 m3/day (1.5 mgd)
  C.   Lime
         Storage (2 bins)
         Gravimetric Slakers  (2)
             Capacity (Max. Each)
             Accuracy
             Range  (Each)
             @  5678  m3/day (1.5  mgd)
         Ejector Pumps  (2)  36.57 m  (120'
             Motor  (3450 rpm)
  D.   Powdered  Activated  Carbon
         Storage  Hopper
        Volumetric  Feeder

        Range
         @ 0.0657 m3/s  (1.5 mgd)
        Slurry Feed Pump  @ 39.0 m (128'
          Motor  (3500 rpm)
        Dust Collector
          Motor
1725
1725
1725
46

46

46
18
14
14
50

50

50
21
34
34
                    68.02 kg (150 Ibs)
                    181.4 kg/day (400 Ibs/day)
                    90.7 kg/day (200 Ibs/day)
                    20 to 1
                    16 mg/1  to  0.8 mg/1

                    45.35 kg/day (100 Ibs/day)
                    20 to 1
                    8  mg/1 to 0.4 mg/1

                    21.8 metric tons (24  tons)
                    2721 kg/day (6000 Ibs/day)
                    2040.75  kg/day (4500  Ibs/day)
                    20 to 1
                    360 mg/1 to 18 mg/1

                    50.95 m3 (1800 cf)

                    453.5 kg/hr  (1,000 Ibs/hr)
                    -  n
               0 to 453.5 kg/hr  (0  to 1000  Ibs/hr)
                    0  to  1920 mg/1
            TDH)    0.0378 m3/s  (60 gpm)
                    5 hp

                    2.123 m3 (75 cf)
                   0.2095 m3/hr (7.4 cf/hr)
                   34 kg/hr (75 Ibs/hr)
                   20 to  1
                   144 mg/1 to 7.2 mg/1
           TDH)    0.00144 m3/s (23 gpm)
                   5 hp
                   0.2359 nrVs   (500 cfm)
                   3/4 hp
                                     80

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    E.   Miscellaneous Chemicals
          Acid Storage [66° Baume1)
          Polymer Storage
             Dry Storage (Portable Chemix)
             Batch Size (Chemix)
             Alum Room Day Tank
          Alum Storage                   22.6 m
          Metering Pumps (4)  0.861 Pa (125 psi)
             § 0.0657 m3/s (1.5 mgd)
             Motor (DC)

15.   Plant Flow Meters
          Trickling Filter -
             Recirculation - Propeller
          Chlorine Tank Effluent -
             Rectangular Weir
          Tertiary Plant Influent -
             25.4 cm (10")Magnetic Meter
          Underflow Sludge Flow Rate
             7.62 cm (3") Magnetic Meter

          Plant Effluent
          Parshall Flume
             228.6 mm (9") Throat

16.  Emergency Generator
          KW Rating @ 0.8 Power Factor
          Engine Type 6 cylinder in line diesel
          Engine Speed
          Brake Horsepower Available
          Fuel Consumption (100% load)

17.  Boiler
          Horsepower
          Steam Production
          Fuel Consumption (150,000 BTU/gal)

18.  Fuel Oil System
          Storage (Buried)
             Generator
             Boiler (2)
          Boiler  Fuel Oil Pumps (2)
             Type
16,655.8 £ (4400 gal)

0.2547 m3 (9 cf)
94.61 £ (25 gal)
208.2 I (55 gal)
(800 cf) 22712.4 I (6000 gal)
5 to 79 I  (1.3 to 20.8 gal)
0.87 mg/1 to 13.87 mg/1
1/4 hp
0.0126 to 0.1373 m3/s
    (200 to 2180 gpm)

0.00067 to 0.01008 m3/s
     (11 to 160 gpm)


0.0316 to 0.0945 m3/s
     (500 - 1500 gpm)
200 kw
4 cycle
1800 rpm
311 hp
0.0617 m3/hr  (16.3 gph)
200 hp
0.8687 kg/s  (6900 Ibs/hr)
0.211 m3/hr  (55.8 gph)
2119.83 I  (560 gal)
30283.29 H  (8,000  gal) each

Gear
                                      81

-------
             APPENDIX B
SCHEMATICS OF LIQUID AND SLUDGE FLOWS
                 82

-------
STP=City  Secondary Wastewater
    Treatment Plant
IF = lnfluent Tank
M = Flow Meter
CUi =#] Contact Unit
CU2=#2  Contact Unit
ST = Sludge Thickener
SVF =  Sludge  Vacuum  Filter
ET = Equalization Tank
SB = Splitter Box
F = Gravity Filter
VW = Viewing  Well
PF = Parshall Flume
SD  =  Stinky  Ditch
SHP = Sludge Pond
SW = Swamp East Side of Plant
                   APPENDIX B, FIGURE B-l.

-------
    Activated Corbon
    Ba, Feed Hopp
 j Gate Valve       =^= Process Piping     ^^	^	I
 * Ball Valve       -4-i-f Process Bypass Piping,  -----*- --'-_—a A.  f
 * Plug Valve       	Sludge Piping              i '*	f^^^~V LJ"ie Storage and                                            Qt
-2£;±      — ^tllo^Pipt9          MlLl_J'N.dH,p.B                                             JLjh     	.	
 I Pres,ure Regulating Valve           P 8              V/ V/                                                 Chlorine n n      _T      Vaream.l.r        4 Carbon Dioxide Feeo
 < Pressure Relief Valve                     T         Y   f    Service Water                                Cylinders S Scale Jl|   , Vent I    Distribution Panels       (,Vent.-Hea,
 Tsrr:-1-                         oJ|[-5~^^                                                ch,or~!:i|54^p/       NSsJiJvL^

 C"bo" _Jt                        Dust Collectors    T       f   ^Jt	^"f-l'-t ^f!-^	^	>_C"_", ~ "^.V-i	__<_      Tff CO 2 Stom^eand

        N               	Water Pump,  ^      |  ^Elector. |             r<_^r.Sefvite Wo,,rS.,o,ess Water  '    It	1  ?  f f|	H        Corbon Dioxide Feed System
       "ftBolometer -ifH;              Lime Storage and Feed System                  '  "" S1°ro9e Tan                 I    1  L  I 11     '                   Sulluric Acid
.ssembly	-\  \ _     ^ ['  *j" )                                    Chemical fjj 	f Vhem ."«e"te"rin5>ump'«,	*"'"[*"["?(	T °?" " " " *"          Storage Tank, „
                                                                                                                                                                                     Service
                                                                                                                                                                                     Water
                                       Chlorine Cylinder
                                                                --
                                                 condary Chlorine Feed Syst
                                                      fChbrinato,         Service Wa^erpj   /
                                                      '--	>	•,         T	L)Bl-J
 I
CO
       Chrfm'Lrs   f™       "^ B""«i C°"''°' T"*li™ »""»' C°""°' S~>"d"»   c'S'   ™°^ MTtTw™"'"1
       Chambers   Screen    cbrifier   Box No ,     Fl|ler   Box No j   Oll,aa  ^ ^ 3  chomb(,r    "ln9  %e

          ~1     t    I             I       t    It              i{s
                                                                                  Chemical Metering Pump
                                                                                     Polymer Feed Systerr

                                                                                 Chlorine  Secondary Effluent
                                                                                                         i.rvice WaterJ^,	^,  ^..J,	
                                                                                                                  I—li.»^.|tLj   I
                                                                                                                  1     r-"?=r--fr'-?-r*
                                                                                                                                                      Backwash /  package Lift
                                                             Digested Sludge to Sludge Thickener r~">—	>—	>-- >j  r- -*
                                                                                           *   "*        "*
                 Sludge Gas to
                Slud'ge'GoTSediment « D.ip Trap     P'™<"V   "j
                                            d9e
                                                                                                                        ^•f-T^-Tn-T-	> —
                                                                                                           ic. Watery   ,Fj ^J        i    f Station
                                                                                                                 C  i   *- Cl«inoii)   +  To Drain
                                                                                                                   Thickened Sludge Pump Station                                        Loodina Ar
                                   APPENDIX  B   FIGURE  B-2.    WASTEWATER  TREATMENT  PLANT  FLOW  SCHEMATIC

-------
                                  APPENDIX B




                            Water Budget Equation




   ' Q! + QB - (Q3 + Q8} - (Q5 + Q9 + Q12 + <*16 + V ' (Q14 + Q17 + V ~


     CQ4 + Q7 + Qn) - (Q23 + Q24 - Q27 + Q31)



   = Discharge to Lake - Metered and Recorded



QT = Influent to Tertiary Treatment Process - Metered and Recorded



QD = AWT Plant By-Pass - Not Metered
 D


Q, + Q0 = 27,707 GPD Sludge Withdrawal from CU, + CIL (6-73 thru 3-74 average
 JO                                       1     Z


          nearly constant}




Q5 + Q9 + Q12 + Q16 + Q21 = 18'°39    Constant


Q-. + Qn_ + Q.0 = 24,376 GPD    Constant
 14    1/    4o


Q  + Q  + Q   = CU, + CU2 + SB  Overflows rarely occur



Q23 + Q24 + Q2y + Q31 = 200 GPD   Constant



   = QT + QD - 27,707 - 18,039 - 24,376 + 200
      1    B


   = Qj + QB - 70,000



Q  = Flow from City Collection System - Not Metered



Q  = Secondary Effluent -  Metered and Recorded
 O


Q  = Influent to Tertiary Treatment Process - Metered and Recorded



   = Discharge to Shagawa Lake -  Metered and Recorded
QD = AWT Plant By-Pass - Not Metered
 B


QT = Influent to AWT Plant



Q  = Pumped from Influent Tank to CU.



Q  = Sample Flow (TCJ



Q  = Sludge Withdrawal from O^




                                     85

-------
 Q4  = Overflow from CU



 Q   = Sample Flow (TCJ
  b                   2.


 Q6  = Effluent from CU ,  Influent  to CU



 Q?  = Overflow from CU2



 Qg  = Sludge Withdrawal  from CU-



 Q9  = Sample Flow (TS^



 Q1Q  = Effluent from CU2,  Influent  to SB



 Qn  = Overflow from SB




 Q12  = Sample Flow (TS2)




 Q13  = Effluent from SB,  Influent to  F



 Q14  = Filter Backwash  Water



 Q15  = Effluent from F, Influent to VW



 Q16  = Sample Flow  (TVW)



 0-_  =  General  Use  Flow (like washing down floors)



 Qlg  =  Special  Use  Flow (slaking lime, C02 feed, etc.)



 Qig  =  Effluent  from VW



 Q2Q  =  Influent  to  PF



 Q2   =  Sample Flow  (TP)



Q22  =  Chemical  Feed Prior to SB




^23  =  Sulfuric Acid Feed



Q24  =  Ferric Chloride Feed



Q25  = Chlorine  Feed, Part of Q




Q26  = Water § Chemical Feed to CU



Q   = Ferric Chloride Feed
                                    86

-------
Q   = Fiber Bearing Water



Q?q = Carbon Dioxide Feed



Q   = Water § Chemical Feed to CU



Q   = Pol/electrolyte (Uses City Service Water)



Q   = Fiber Bearing Water
 O ^


Q _ = Lime Feed



Q   = Wastewater (Not Secondary) Influent to IF
 O^


Q _ = Internal Plant Sewer - Showers, Toilets, etc.
 oo


Q,fi = Seepage into Equalization Tank



Q__ = North Side Floor Drains



Q_0 = South Side Floor Drains
 JO



^39 = Qll + <*14 + Q38 + ^36 + ^35


Q Q = Sludge Vacuum Filter Belt Wash Water



Q41 = Sludge Vacuum Filter Filtrate



Q42 = Sludge Thickener Overflow





Q43=Q40+Q41 +Q42


Q   = Equalization Tank Contents Pumped to City Plant
Q   = Stinky Ditch



Q._ = Drainage from Sludge Holding Pond



0.0 = Sludge Vacuum Filter Belt Wash Water
 4o



^49 = <*14


Q50 = Sludge from Thickener (Use only when Sludge Vacuum Filter is down.)



Q   = Solids to Sanitary Land Fill
                                    87

-------
Q „ = Sludge from Thickener to Vacuum Filter




Q53 - Primary Sludge from City Plant to Sludge Thickener




Q 4 = Swamp, East Side of Plant (Receives Septic Tank Effluent)
                                    88

-------
                               APPENDIX C

                          SECONDARY PLANT DATA
    Month
    Table C-l  Primary Influent (mg/1)

  Total     Suspended   Alkalinity
Phosphorus    Solids     as CaC03    B.O.D.
                                pH
July 1973
August
September
October
November
December
January 1974
February
March
7.08
4.47
4.14
4.05
11.01
	
9.09
9.00
7.72
276
297
74
68
357
	
177
203
162
181
187
137
148
235
	
204
186
172
136
66
60
39
80
	
113
120
109
7.54
8.18
7.36
7.66
8.24
	
8.25
8.12
7.89
Average
   7.07
202
                                           181
90
7.90
                                89

-------
                   Table  C-2   Secondary Effluent  (mg/1)

              Total      Suspended    Alkalinity
    Month    Phosphorus      Solids       as CaC03     B.O.D.      pH

 July  1973       4.39            79            142        68

 August          3.16            75            149        23.5      7.43

 September       3.36            16            143        23.9      7.22

 October         2.93            23            136        18.1      7.26

 November        2.96            30            133        40        7.43

 December        —            __            	        	

 January 1974    4.33            58            142        	       7.44

 February        4.78            33            135        46        7.30

March           4.57            42            130        56        7.22



Average         3.81            44            139        39        7.33
                              90

-------
          Table C-3  Removal Through Trickling Filter Plant (%)
Month
July 1973
August
September
October
November
December
January 1974
February
March
Total
Phosphorus
46,0%
34
20
27
68
--
51
48
41
Suspended
Solids
72.0%
75
78
66
92
--
67
84
74
Alkalinity
as CaC03
22.0%
20
-7
8
43
--
30
27
24
B.O.D.
50,0%
64
60
53
50
--
--
62
49
Average           45.6%          76%           21%           55%
                                91

-------
                                    APPENDIX D
               YEARLY DATA SUMMARY - PLANT OPERATION AND PERFORMANCE *
                            Influent to Tertiary Plant
Parameters
Total Phosphorus Unfiltered
Total Phosphorus Filtered
Suspended Solids
Turbidity (JTU)
TOG
TIC
Calcium
Magnesium
Alk as CaC03
Iron
1973
April
3.62
2.42
37.0
25.0
29.9

39.8
6.3
144.0

May
3.61
2.30
46.0
31.4
28.5

47.8
8.62
153.0

June
4.96
3.34
60.1
16.7
40.4

53.9
8.3
154.0

July
5.22
2.74
105.0
30.3
39.8

56.8
7.2
156.0

August
4.66
2.30
100.0
22.8
35.8

53.4
7.5
161.0

September
3.83
1.93
71.0
25.0


47.4
6.7
159.0

All units mg/1 unless otherwise noted.

-------
                                        Influent to Tertiary Plant  (Continued)
Parameters
Total Phosphorus Unfiltered
Total Phosphorus Filtered
Suspended Solids
Turbidity (JTU)
TOG
TIC
Calcium
Magnesium
Alk as CaCOs
Iron
October
3.61
1.79
63.0
16.9


54.0
6.86
148.0
5.30
November
4.04
2.74
44.0
10.3


45.0
6.8
143.0
2.31
December
4.13
2.96
36.0
10.67
33.4

30.0
6.1
134.0

1974
January
4.44
3.03
41.0
11.4
34.7
27.2
34.7
5.6
137.0
1.93
February
6.59
3.49
122.0
34.51
62.87
35.63
27.0
5.4
147.0
3.12
March
5.98
3.10
110.0
41.47
53.25

27.93
5.65
138.0
3.84
Yearly
Average
4.56
2.68
70.3
23.0
39.9
31.4
43.2
6.75
148.0
3.3
(0

-------
First-Stage Lime Clarifier - Operation  and Performance Data
Parameters
Flow (MGD)
Overflow rate (gpd/sq ft)
Lime (CaO)
Polymer (Betz 1150)
PH
Upper Mix Zone Solids Vol.
fml/1)
Lower Mix Zone Solids Vol.
fml/1)
Blanket (ft)
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Magnesium
Iron
Alk as CaCOs
1973
April
1.164
490
283.0
0.53
12.07
84.0
249.0
4.7
0.568
0.108
14.0
6.0
-
-
122.0
-
-
-
May
1.356
571.0
266.0
0.33
11.96
249.0
388.0
6.8
0.318
0.122
12.0
6.1
-
-
109.0
0.49
-
-
June
1.107
466.0
287.0
0.19
11.87
280.0
351.0
7.6
0.267
0.148
9.8
2.67
-
~
105.2 !
-
-
~ i
July
1.302
548.0
340.0
0.24
11.90
236.0
299.0
9.1
0.306
0.123
9.5
2.11
-
-
154.0
-
-
_
August
1.50
631.0
342.0
0.21
11.88
199.0
275.0
6.5
0.249
0.107
16.0
1.86
19.7
-
149.0
0.12
-
,_
September
1.33
560.0
343.0
0.20
11.90
147.0
191.0
4.9
0.269
0.093
8.0
1.89
_
-
153.0
0.14
-
^_

-------
First-Stage Lime Clarifier -  Operation  and Performance Data (Continued)
Parameters
Flow (MGD)
Overflow rate (gpd/sq ft)
Lime (CaO)
Polymer (Betz 1150)
pH
Upper Mix Zone Solids Vol.
(ml/1)
Lower Mix Zone Solids Vol.
(ml/1)
Blanket (ft)
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Magnesium
Iron
Alk as CaCO^
October
1.38
581.0
296.0
0.19
11.84
185.0
236
5.4
0.217
0.089
8.3
1.82
-
-
140
0.23
0.12
-
November
1.046
440.0
301.0
0.17
11.90
220.0
259
5.3
0.205
0.085
8.5
1.41
-
-
115
.1.2.7....
0.071
-
December
0.92
387.0
281.0
0.21
11.91
188.0
215
5.0
0.27
0.091
6.5
1.27
20.8
-
101
0.95
0.105
-
1974
January
0.85
358
274.0
0.19
11.95
134.0
151
4.6
0.347
0.094
7.0
1.53
19.3
3.72
94.2
0.6
0.92
-
February
0.82
345
282.0
0.21
12.03
253.0
283
5.5
0.284
0.127
7.0
2.41
21.57
4.31
98.6
0,2
0.089
1
March
0.88
371
271.0
0.23
12.03
289.0
332
6.22
0.279
0.126
9.0
2.17
29.46
-
101.05
0.25
0.119
-
Yearly
Average
1.14
479
297.0
0.24
11.94
205
269
6.0
0.298
0.109
9.6
2.60
22.2
4.01
120
0.47
0.099
-

-------
                                 Second-Stage Lime Clarifier - Operation and Performance Data
VD
Parameters j
I April May
Flow (MGD) 1.164 ! 1.356
Recirculation (MGD) i 0.183 i 0.208
Overflow rate (gpd/sq ft)
C02 118 95
FeCl3 as Fe 5.60 6.07
PH 9.60 9.56
Solids Vol. (ml/1) UMZ 95 45
Solids Vol. (ml/1) LMZ | 106 i 5.5
Blanket (ft) 6 1.9
Total P - Unfiltered ~^ 0.171 ~*~ 0.110
_ _ . j ! 	 i
Total P - Filtered 0.074 0.060
.. . . . i.. .
Suspended Solids 5 \ 6
Turbidity (JTU) 3.1 1 3.2
1UL 20.5 j 15.4
TIC - i _
Calcium 57.3 j 47.7
Iron - i
Alk as CaCO^ 89.4 j 74.2
i
June j
1.107 |
0.196 i
i
82 ;
5.57 :
9.56 !
40 |
46
2.9
0.097
0.024
8
2.53 ;
-
-
25.4
-
68,9
July
1.302
0.199

125
4.50
9.66
61
74
2.8 |
0.137 i
0.047 '
12 ;
2.40 i
i
:
40.9
-
72.7
j
August
1.50
0.199

131
5.79
9.64
31
41
2.8
0.070
0.020
11
T.88~"
-
-
46.6
-
55.8
!
i
! September
i 1.33
| 0.198

; 122
I 6.56
! 9.61
! 140
i 162
! 3.8
1 0.046
! 0.019
| 5
T 	 "6" .'si 	
i
-
! 26.4

1 47.8

-------
Second-Stage Lime Clarifier - Operation  and Performance Data (Continued)
Parameters
Flow (MGD)
Recirculation (MGD)
Overflow Rate (gpd/sq ft)
C02
FeCl3 as Fe
PH
Solids Vol. (ml/1) UMZ
Solids Vol. (ml/1) LMZ
Blanket (ft)
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Iron

Alk as CaCOs
October
1.38
0.174

108
5.87
9.60
146
173
4.0
0.034
0.018
6
0.94

! ~
27.8
-

i —
November
1.05
0.159

98
6.07
9.60
140
160
3.4
0.056
0.031
7 '
1.63
-
-
23.1
0.44
. . 	 	 	 	
-
December
0.92
0.166

79
5.79
9.59
180
194
4.3
0.046
0.024
4
1.28
19.0
7.04
27.4
0.43
_ 	 — 	
-
1974
January
0.85
0.164

81
5.88
9.55
148
160
3.9
0.060
0.031
3.5
0.99
14.6
10.0
34.7
0.544
| 	 	 	 •- " 	
-
February
0.82
0.160

82
7.13
9.62
160
177
4.0
0.060
0.027
7
1.38
15.7
12.68
36.0
0.590
	 —
-
March
0.88
0.166

80
7.19
9.65
99
113
3.3
0.105
0.017
11
3.38
24.58
-
36.7
0.717

-
Yearly
Average
1.14
0.181
556
100
6.0
9.60
107
122
3.6
0.083
0.033
7.1
1.96
18.3
9.9
35.8
0.544

68

-------
                                          Hravity Filter  Influent Data
00
Parameters
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Magnesium
Alk as CaC03
Iron
Total Solids
Temperature (°C)
FeCl3 as Fe+3 (dosage)1
Cl2 (dosage)
1973
April
0.171
0.074
5
3.1
-
-
57.3
0.&5
-
-
303
-
0
1.92
1 !
May | June
0.115 ' 0.098
0.022 j 0.043
15 j 7
5.9 ! 2.4
1
i
39.3 i 28.0
0.59 ;
57.0 i 40.0
I
224 i
! 13.0
2.38 i 2.12
3.08 I 2.98
July
0.142
0.073
8
1.53
_
-
36.6
-
43.4
-

15.1
2.20
3.80
August
0.073
0.039
7
1.21
_
_
42.8
-
40.4
-

15.4
2.24
4.84
September
0.043
0.016
7
1.30

.
27.0
-
24.0
-

16.2
2.42
3.65
                (1)  Starting May 10,  1973

-------
Gravity Filter Influent Data (Continued)
Parameters
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Magnesium
Alk as CaCO?
	 O
Iron
Total Solids
Temperature °C
FeCl3 as Fe+3 (dosage)
C12 (dosage)
October
0.046
0.019
6
1.48
-
-
38.0
-
20.5
3.15
239
14.8
2.32
2.79
November
0.054
0.027
7
1.45
-
-
25.0
-
22.8
2.98
176
11.7
2.88
2.85
December
0.045
0.017
8.7
1.83
18.8
5.9
29.7
-
33.5
3.40
154
9.6
3.23
2.62
1974
January
0.061
0.021
9
1.43
17.5
9.1
36.2
-
49.9
3.47
205
8.82
3.24
2.34
February
0.081
0.036
10
2.19
16.08
10.37
41.09
-
42.7
3.23
274
8.66
3.41
2.40
March
0.144
0.065
14
2.8
25.53
-
52.5
-
44.8
4.24
-
7.68
5.51
3.17
Yearly
Average
0.089
0.038
8.6
2.22
19.5
8.5
37.8
0.62
38.1
2.25
225
12.10
2.66
3.04

-------
                                             Tertiary Plant Effluent Data
Parameters
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOG
TIC
Calcium
Magnesium
Alk as CaC03
Iron
BOD
Total Coliform (No./lOO ml)
Fecal Coliform (No./lOO ml)
r\ r*
u . w .
Residual Chlorine
PH
1973
April
0.070
0.058
2
2.6
19.9
-
65.7
0.58
90.4
-
-
-
-
_
0.46
7.67
May
0.060
0.046
1
1.2
18.4
-
49.7
0.57
59.6
_
-
-
_
_
0.52
7.55
June
0.046
0.033
0.76
0.45
16.0
_
28.7
0.3
38.7
_
23.8
0
0
9.1
0.55
7.42
July
0.076
0.062
1.6
0.17
12.1
_
36.6
0.2
42.2
_
10.3
0
0
9.3
0.45
7.53
August
0.041
0.038
1
0.11
8.9
_
37.6
0.3
32.4
_
-
0
0
9.3
0.41
7.50
September
0.022
0.016
1
0.33

.
27.4
0.11
23.9

_
0
0
8.9
0.51
7.51
o
o

-------
Tertiary Plant Effluent Data  (Continued)
Parameters
Total P - Unfiltered
Total P - Filtered
Suspended Solids
Turbidity (JTU)
TOC
TIC
Calcium
Magnesium
Alk as CaC03
Iron
BOD
Total Coliform (No./ 100 ml)
Fecal Coliform (No./lOO ml)
D.O.
Residual Chlorine
PH
October
0.023
0.017
1.7
0.44
-
-
40.4
0.15
22.3
0.20
-
0.6
0.16
9.25
0.51
7.45
November
0.032
0.029
1.0
0.33
-
-
24.8
1.27
22.1
1
0.21
-
0
0
10.04
0.25
7.53
December
0.021
0.017
1.4
0.32
16.7
5.88
27.4
0.43
33.7
0.17
-
0.1
0
10.3
0.17
7.54
1974
January
0.026
0.022
1.0
0.14
15.0
-
36.3
0.56
49.9
0.176
3.78
0.3
0
10.6
0.14
7.50
i
February
0.043
0.036
1.5
0.20
16.2
9.98
41.53
0.3
42.7
0.175
11.27
0
0
10.83
0.16
7.40
March
0.077
0.065
2
0.43
23.75
-
53.51
0.28
44.8
o . 3 do"1
-
0
0
11.4
r~ 0.18
7.47
Yearly
Average
0.045
.037
1.3
0.56
16.3
7.9
39.1
.42
41.9
0.21
12.3
0.10
0.02
9.9
0.36
7.50

-------
                    APPENDIX E
TOTAL PHOSPHORUS DATA:   APRIL,  1973 THRU MARCH,  1974
                       102

-------
   O)
   E
   Of
   O
   I
   o.
   
   O
   X
   <
   o
                     TERTIARY PLANT
                      INFLUENT TOTAL P
                        (FIRST STAGE INFLUENT)
                    FIRST STAGE EFFLUENT
                         TOTAL P
                   SECOND STAGE
                   EFFLUENT TOTAL P
                                                        ' I  I I  I I I I
                                            5  15  25  5 15 25  5  15 25
                                             AUG.    SEPT.    OCT.
5 15 25  5  15  25
 JUNE    JULY
5 15  25  5  15  25
  APR.    MAY
APPENDIX E, FIGURE E-l.   DAILY TOTAL P CONCENTRATION  FROM APRIL 1, 1973 TO MARCH  31, 1974 (mg/l).

-------
Table E-l
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
April
1973
1
2
3
4
5
6
7
8
9
10
11
!2
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE

































V

SEC.
EFFL.





4.74
3,20
3.79
6.26
4.18
4.35
4.24
4 71
3.99

3.61
4.45
4.56
4.09
3.57
3.67

4.09

4.40
4.03
3 81
—3,17
4.06
5.11


4.188
0.6323
15.1
1st STAGE
CLAR.
INF.
3.42
3.89
* HQ
3.57
V4Q
2.92
3.31
3.07
4.43
3.73
3.78
4.04
\ <;?
3.63
\ ^Q
3.34
3.64
3.70
3.46
3. 49
3.14
2.80
3.20
4.02
5.25
3.81
3 6J1
4.07
2.83
4.54


3.622
0.5149
14.2
1st STAGE
CLAR.
EFFL.
0.582
0.439
n c;^
0.729
n.s.vi
0.540
n.Qfl3
0.902
0.943
0.717
0.674
0.641
0 68.8
0.514
0.488
0.586
0.627
0.579
0.629
0.935
0.665
0.494
0.454
0.280
0.331
0.259
0.295
0.413
0.371
0.294


0.5682
0.1938
34.1
2nd STAGE
CLAR.
EFFL.
0.122
0.111
n 177
0,155
n.?.?4
0.249
°-26Z
0.238
0.205
0.232
0.191
0,190
n ?ns
0.21.7
0.184
0.159
0.201
0.197
0.208
0.179
0.186
0.169
0.138
0.126
0.101
0.100
n inn
0.101
0.143
o.n:


0.1713
0.0494
28.9
D.M.
FILTER
EFFL.
0.030
0.022
n n?s
0.032
n.nsn
0.026
0.032
0.035
0.024
0.039
0.078
0.072
n n?Q
0.091
0.073
0.080
0.100
0.101
0.107
0.091
0.105
0.101
0.101
0.089
0.078
0.079
n n?s
0 078
0.114
0.094


0.0695
0.0305
43.9
EFFL.
TO LAKE

0.032
n.nss
0.038
n.n*q
0.0.35
0 . 036
0.035
0.039
0.043
0.065
0.074
n n?^
0.077
0.070
0.080
0.096
0.104
0.102
0.085
0.114
0.090
0.083
0.079
0.073
0.068
n n^t;
n nvs
0.100
0.094


0.0690
0.0251
6.4
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
83.0
88.7
8^.1
79.6
84.6
81.5
72.7
70.6
78.7
80.8
80.2
84.1
sns
85.8
85.6
82.5
82.8
84.4
81.8
73.2
78.8
82.4
85.8
93.0
93.7
93.2
ai a
SQ Q
86.9
93.5


83.84
5 . 988
7.14
2nd STAG
LIME
CLAR.
79.0'
74.7
7fiT ^
78.7
58.4
53.9
7Q-4
73.6
78.3
67.6
71.7
70.4
fiq.8
57.8
62.3
72.9
67.9
66.0
66.9
80.9
72.0
65.8
69.6
55.0
69.5
61.4
f.f. ^
7^L ^
61.5
62.2


68.54
7.201
10.5
DUAL-
MEDIA
FILTER
75.4
80.2
78 n
79.4
86.6
89.6
80.0
§5.3
88.3
83.2
59.2
62.1
6? n
58.1
60.3
49.7
50.2
48.7
48.6
49.2
43.5
40.2
26.8
29.4
22.8
21.0
oo n
77 R
20.3
15.3


54.61
24.24
44.4
TERTIARY
PLANT
99.1
99.4
qq ?
99.1
99.1
99.1
99.0
98.9
99.5
99.0
97.9
98 2
Q7 R
97.5
97 g
97.6
97.3
97 3
96.9
97.4
96.7
96.4
97.4
98.0
98.6
98.2
OT Q
qs 1
96.0
97.9


98.07
0.9340
0.952
SEC. PLUS
TERT.
PLANT



































  EPA-280 (Cin)
  (12-75)

-------
    Table E-l ("continued")
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
May
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE

































V

SEC.
EFFL.
4 74


3.70
34^
_2 29

7 45
2.77
2.22
2 81
3 m
7 99
3 ^8

^ ^2
3 55
4.04
4 68
3 30

3.74
2.78

7 qi
3.32
3.43
4 74
3 q4

3 60

3.384
0 7069
20.9
1st STAGE
CLAR.
!NF.
4.74
3.64
3 70
3.49
3 3q
7.88
3 70
7 63
2.91
2.85
3 42
7 95
3 78
3 49
3 30
353
3 85
3.52
4.04
3 66
5 76
4.63
.3.. 37
4 81
3.06
3.28
.3.. 3 5
4 17
4 qq
4 1 1
3 7°

3.655
0 6635
18.2
1st STAGE
CLAR.
EFFL.
0.307
0.280
n 5^0
0.557
n 572
0.500
0.295
0 384
0.352
0.208
0 230
0 760
0 777
0 2c;2
0 307
0 276
o 798
0.288
o 298
0.274
0 781
0.298
0.301
0 346
0.367
0.277
o.2oq
0 21Q
0.253
0.25.3
n 3Qq

0.3178
0.9650
.30.4
2nd STAGE
CLAR.
EFFL.
0.129
0.094
0 102
0.175
n 14D
0.147
0.101
0 1 oq
0.105
0.080
0 093
0 108
0 114
0 114
0 143
0 130
0 1 70
0.112
0.122
0.115
0111
0.125
0.130
0 162
0.152
0.125
0.094
n n«o
0.086
0.091
n ins

0.1151
0.0207
18.0
D.M.
FILTER
EFFL.
0.108
0.072
0.053
0.058
n 076
0.079
0.053
0 046
0.073
0.053
0 051
0 051
O.053
n n5i
n 065
n 064
0 050
0.061
0.065
0.068
0.058
0.065
0.064
0.086
0.073
0.065
0.047
0 036
O.033
0.0.39
n 047

0.0601
0.0154
25.6
EFFL.
TO LAKE
0.103
0.059
0.049
0 . 048
0 067
0.196

0 091
0.089
0.059
0.062
0 059
0.049
o 049
0 053
0 043
0 . 043
0.051
0.057
0.051
0.048
0.048
0.052
0.070
0.057
0.058
0.050
0 040
0 . 0.38
0 . 0.36
o 044

n.0605
0.0298
49.2
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
93.5
97.3
85.7
84 0
8^ 1
87 6
90.8
85 4
87.9
92.7
9.3.3
91 .7
91 .6
97 8
90 8
97 7
97.3
91.8
92.6
92.5
94.7
93.6
91.1
92.8
88.0
91.6
93.8
94 7
95.0
9.3.8
91 8

90.97
3.457
3.8
2nd STAGE
LIME
CLAR.
58.0
66.4
80.8
77.6
75 5
70 6
65.8
71 6
70.2
61.5
59.6
58.5
58.8
54 8
52.6
57 9
59.7
61.1
59.1
58.0
60.5
58.1
56.8
53.2
58.6
54.9
55.0
63 5
66.0
64.0
65 0

62.22
7.319
11.76
DUAL-
MEDIA
FILTER
16.3
73 4
48.0
53.6
45 7
46 3
47.5
57 8
30.5
33.8
45.2
52.8
5.3.5
55 3
54.5
50 8
58.3
45.5
46.7
40.9
47.7
48.0
50.8
46.9
52.0
48.0
50.0
55 . 0
61.6
57.1
56 . 5

47.74
9.998
20.9
TERTIARY
PLANT
97.7
98 0
85.7
98 3
Q7 8
97 3
98.3
98 3
97.5
98.1
98.5
98.3
98.4
98 5
98.0
98.7
98.7
98.3
98.4
98.1
98.9
98.6
98.1
98.2
97.6
98.0
98.6
99.1
99.3
99.1
98.8

9?.89
2.310
2.4
SEC. PLUS
TERT.
PLANT



































O
tn
      EPA-280 (Cin)
      (12-75)

-------
o
ON
Tabl
DATE
June
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
•»T
28
29
30


MEAN
STDDE
%CV
e E-l f continued! TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE

































V

SEC.
EFFL.

4 78
3.64
5 IS



4 53
























4.532
n 6^94
iM
1st STAGE
CLAR.
INF.
4.10
4 63
4.10
•; 33
4.71
4.29
4.57
A 4R
6.714
4.65
5.72
s 69
4.93
4.50
4 7Q
4.5?
3 7n
5.65
5.fifi
5 32
A 89
4 49
5.11
4 QQ
4 97
4 20
r- r\ y
n -111
6.08
5.17
5.06


4.955
0,6401
12.92
1st STAGE
CLAR.
EFFL.
0.331
0.996
0.341
0.269
0.273
0.280
0.260
n 7*9
0,285
0.260
0.288
n 999
0.278
0.269
n 963
0.306
0.22Q
0.237
0 . 245
0 2°1
n 749
n 979
0.238
JL_224_
n 75Q
n 278
f\ r\ TV
11. ^.T.T
n 238
0.249.
n 963


_Q.2669
n n796
11.10
2nd STAGE
CLAR.
EFFL.
0.109
0.125
0.127
0.122
n 136
0.133
0.114
n DQ7
n r>Q4
n n«Q
0.086
n in7
0.118
0.094
o.nsq
0.109
0.083
0.083
0.100
n nan
n 089
0.084
0.093
0 . 083
n nsq
n ns4
u. u/»
n n7*
0.082
n nQ4


0.0982
0.0176
17.9
D.M,
FILTER
EFFL.
0.044
0.048
0.048
O.OS9
n nss
0.060
0.050
n .05.^
n n4fi
n n^o
0.043
0.048
0.050
0.048
0.046
0.050
0.043
0.033
0.050
n n3<;
0.044
0.039
0.060
0.062
0.053
n.fUR
U.UJ3
n n49
0.037
n n38


0.0464
0.0075
16.2
EFFL.
TO LAKE
0.041
0.041
0.037
0.049
n n^3
0.052
0.052
n n47
n n3s
n n3<;
0.040
0.043
0.053
0.042
0.028
0.045
0.032
0.053
0.050
n n4n
0.040
0.043
0.047
0.063
0.05.3
O.n47
U. UH-3
n n3Q
0.036
0.037


0.044
0.0076
17.4
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
91.9
93.6
91.7
95.0
94 9
93.5
94.3
94.1
95.5
94 4
95.0
94.7
94.4
94.0
94.5
93.2
93.8
95.8
95.7
94 ^
94.9
95.1
95.3
95.5
94.8
93.5
| 96.1
96.1
95.3
94.8


94.51
1.065
1.13
2nd STAGE
LIME
CLAR.
67.1
57.8
62.8
54.6
50.2
52.5
56.2
63.0
67.0
65.8
70.1
64.2
57.6
65.1
66.2
64.4
63.8
65.0
59.2
72.5
64.3
62.2
60.9
62.9
65.6
69.8
f f i
UU . J.
69.3
66.1
64.3


63.22
5.20
8.23
DUAL-
MEDIA
FILTER
59.6
61.6
62.2
68.0
57.4
54.9
56.1
45.4
51 .1
56.2
50.0
55.1
57.6
48.9
48.3
54.1
48.2
60.2
50.0
56.3
50.6
53.6
35.5
25.3
40.4
42.9
i- r\ f
^\J . U
42.5
54.9
59.6


51.90
'8.65
16.66
TERTIARY
PLANT
98.9
99.0
98.8
99.3
98.8
98.6
98.9
98.8
99.3
99.2
99.2
99.2
99.0
98.9
99.0
98.9
98.8
99.4
99.1
99.3
99.1
99.1
98.8
98.8
98.9
98.9
r\r\ *r
yy . j
99.3
99.3
99 2


99.04
0.2125
0.21
SEC. PLUS
TERT.
PLANT

































, *

        EPA-280 (Cm)
        (t2-75)

-------
Table E-l (continued)
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
July
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE





5.93



7 63
11.5





5.53
11.0





5.11
3.82
6 16






7.085
V 2.785
39.3
SEC.
EFFL.









5 66
4.14





4.83
5 18




4.40
5 . 35
3.27
7 7Q






4.390
1.139
25.9
1st STAGE
CLAR.
INF.
4,54
5.87
5 80
5.60
5.29
3. 60
8.37
4.40
6.66
5 48
5.93
2.08
/I /|5
4 43
6.40
7 83
5.42
4 83
4.79
4 61
6.65
6.40
4.82
4.43
5.07
^ 66
4.00
7 1Q
6 69
3.74
7 81

5.221
1.408
26.97
1st STAGE
CLAR.
EFFL.
0,765
0.319
n ^2^
0.255
0.229
0 229
0.291
n 777
0.288
n ^07
0.295
0 . 256
0 345
0715
0.229
n ?7n
0.447
0 878
0.463
0 767
0.255
0.216
0.235
0.525
0.317
o ^71
0.274
n i T\
0 180
0.195
n 201

0.3059
0.1337
43.7
2nd STAGE
CLAR.
EFFL.
0, 177
0.120
0.105
0.102
0.103
0 124
0.149
0 147
0.337
0 V*
0.289
0.219
0 119
0 1 51
0.1.31
0 1 37
0.166
0 1QQ
0.176
0118
0.078
0.065
0.101
0.142
0.252
0 1 ?q
0.090
0 nc;4
0 044
0.042
0 047

0.1420
0.076K
53.6
D.M,
FILTER
EFFL.
0.044
0.05.3
0.057
0.053
0.051
0 Ofi5
0.093
0 075
0 1.38
o 104
0.118
0.118
0 097
o 105
O.OQ1
0 083
0.127
0 1 37
0.104
0 06q
0.044
0.043
0.063
0.089
0.100
o 074
0.053
o o^q
0 021
0.025
0,074

0.0757
0.0333
44.0
EFFL.
TO LAKE
0.043
0.044
0.057
0.032
0.051
0 065
0.093
0 075
0 138
o 104
0.123
0.118
0 0Q7
0105
0.091
0 08^
0. 127
0 1 ^7
0.104
0 06q
0.044
0.043
0.063
0.089
0.100
0 660
0.114
n 0^6
o 025
0.024
0,074

0.1125
0.1958
174.0
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
94.2
94.6
90.9
95.4
95.7
q^ 6
96.5
95 0
95.7
Q4 S
95.0
87.7
Q9 7
q5 i
96 4
Q6 6
91 .8
87 q
90.3
q4 7
96.2
96.6
95.1
88.1
93.7
8q q
93.2
q7 6
qy \
94.8
97.8

93.66
3.227
3.44
2nd STAGE
LIME
CLAR.
54.0
67 . 4
80.0
60.0
55.0
45 q
48.8
33 8
17 0
6 q
2.0
14.4
56 8
79 8
42.8
m 1
62.9
76 0
62.0
^ s
69.4
69.9
57.0
72.9
20.5
65 7
67.2
68 8
7^ f>
78.5
79.1

51.41
25.59
49.78
DUAL-
MEDIA
FILTER
63.9
55.8.
45.7
48.0
50.5
47 6
37.6
49 0
5q 0
67 8
59.2
46. 1
34 9
30 5
30 . 5
37 1
23.5
33 7
40.9
41 q
43.6
33.8
37.6
37.3
60.3
4? 6
41.1
35 2
57 ^
40.5
42.9

44.19
10.59
23.96
TERTIARY
PLANT
99.0
qq 1
99.0
99.0
99.0
q« 2
98.9
q8 ^
q? q
q» i
98.0
Q4..3
97.8
q? 6
98.6
qs q
97.7
97 .3
97.8
q8 5
99.3
99.3
98.7
98.0
98.0
98 0
98.7
99 5
qq 7
99.3
qq.i

98.41
0.9896
1.01
SEC. PLUS
TERT.
PLANT





98.9



98.6
99.0





97.7
98.8





98.3
97.4
98.8






98.44
0.593
0.60
 EPA-280 (Cin)
 (12-75)

-------
    Table E-l fcontinuedl
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Aug.
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
IX
^ w
27
28
29
30
31

MEAN
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE




4 HO
4 c;6







2 Q4






1.20
q.74






4.96
3.89


4.47
STDDEV 7 633^
%CV 1 58.91
SEC.
EFFL.




2 7^
3 in






3.31
3 Q2






3.17
.3.16






3.70
3,07


3.1575
0.775.3
8 7?
1st STAGE
CLAR.
!NF.
^ ^2
4.18
6 Ql
4.99
c; 33
3.50
4 4^
9 qi
7 74
3 14
	
2 6q
3,99
4 71
3 %
3.91
q 07
5.30
7,98
5 71
6.23
4.02
4 87
4.97
4.85
3 . QQ
5 11
5,51
5 . 75
5, IS
3.82

4,658
1.37.3 i
9Q 48
1st STAGE
CLAR.
EFFL.
n 211
0.214
0 211
0.241
0 24-0
n,7n<;
0.493
i no
(1,168
0 154
0.190
n 163
0,158
0 21^
0 471
0.191
n 184
n 713
0.190
n 187
0.216
0.208
0.186
0.205
0.705
n , ? 1 5
0 240
0.242
0.249
0 738
0.209

0.2488
0.1576
63 34
2nd STAGE
CLAR.
EFFL.
n 047
0.066
0 048
0.053
n 104
n.iin
0.115
n ]8Q
n. 178
0 110
0.093
n n78
0.1.37
n 083
n n67
0.044
n n.50
n o<;7
0.046
n 040
0.046
0.045
n 043
0.048
n.05i
u. iio.^
n Q^(f
0.060
0.051
n 047
0.046

0.0726
0.0393
^4 16
D.M.
FILTER
EFFL.
n 074
0.029
o 02°!
0.031
0 068
0.076
0.093
0 OQ6
0.068
0 0^8
0.054
0 068
0.048
0 O^R
n 044
0.030
0.029
0 07Q
0.024
0 074
0.025
0.026
0 073
0.030
0.032
u . ii.-ju
o 0^4
0.035
0.029
0.021
0 09/1

0.0415
0.0213
51.25
EFFL.
TO LAKE
0 02^
0.027
0 028
0.0.37
o 074
0.080
0.135
0.6^7
0.777
0 06Q
0.066
0 060
0.057
o ns<^
o 049
0.025
0.031
0 037
0.024
0 07Q
0.033
0.027
0.07.3
0.029
0.032
u. u.iz.
0 036
0.036
0.027
0.028
0 048

0.0699
0.1157
165.41
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
Q6 2
94.9
Q6 Q
95.2
qc; q
94.1
88.9
65 6
97.5
qc; i
99.5
93 9
96.0
qq 4
88 1
95.1
98.0
96.0
93.6
96 7
96.5
94.8
96.1
95.9
95.8
r\ A *-•
i«+. 0
qc; 3
95.6
95.7
95.4
Q4 5

93.14
7.117
8.285
2nd STAGE
LIME
CLAR.
77 7
69.2
77 2
78.0
56 7
46.3
76.7
81 .1
6.0
78 6
51.0
52.1
13.3
61 4
85 8
77.0
72.8
75.6
75.8
78 6
78.7
78.4
76.9
76.6
75.1
77. 2
76 7
75.2
79.5
80.2
78 0

67.14
21.119
31.46
DUAL-
MEDIA
FILTER
48 q
56.1
3q 6
41.5
34 6
30.9
19.1
49 2
61 .8
47 3
41.9
12.8
65.0
33.7
34 3
31.8
42.0
44.2
47.8
40 0
45.6
42.2
46.5
37.5
37.2
*7 ri o
00. 0
39 3
41.7
43.1
55.3
47 »

41.85
10.63
25.40
TERTIARY
PLANT
99 6
99.3
qq 6
99.4
98 7
97.8
97.9
96.7
97.0
98 7
98.0
97.5
98.8
98.8
98.9
99.2
99.7
99.4
99.2
99.6
99.6
99.3
99.5
99.4
99.3
r\r\ 'i
yy . £
99 3
99.4
99.5
99.6
qq,4

98.93
0.8149
0.8237
SEC. PLUS
TERT.
PLANT




98 3
98.3







98 1







99.7






99.4
99.5


98.88
0.722
0.730
o
00
       EPA-280 (Cin)
       (12-75)

-------
o
Tab e E-l f continued} TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Sept
1973
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


MEAN
STD DEI
%CV

RAW
WASTE





3.85
.3.6,3





4.43
3. fin
3 71
3.73
5 71
4,18
4.40
5.50
3 96
3.71
3.85
5.60
4 in
3 16

4.35
3.60



4.143
/0.68027
16.42
TOTAL PHOSPHORUS GONTRATION - mg/l
SEC.
EFFL.





3.02
4.20





7.63
2.83
3.14
2.73
4,18
3.1?
3.32
3.32
7 80
3.n.3
3.13
4.n2
3 03


7.20
1.41



3.359
1.1827
3.5.2
1st STAGE
CLAR.
INF.
2.71
2.08
2 . 35
3.05
2.1Q
2.87
3.01
3.21
4.35
3.79
4. on
1 10
4,83
3.67
4.45
3.84
5.11
4,43
5.66
5.17
3 75
3.05
3.32
3 92
3.46
4 85
4.38
6.76
4.35
3.74


3.8347
1.0603
27.65
1st STAGE
CLAR.
EFFL.
n 7nq
0.134
0.166
0.205
n.247
0.306
0.467
n.4no
0.280
o.soi
n 37i
n 738
n 3QQ
0.341
0.288
0.262
n 76Q
n pss
0.269
0.307
n.33n
0.27.3
0.254
0.259
0 753
n ?3n
0 22°
0.217
0.230
n 2^6


0.2694
0.0655
24.31
2nd STAGE
CLAR.
EFFL.
0.038
0.027
0.023
0.062
n.033
0.043
0.083
0.111
0.057
0 045
n n47
0 034
n n35
0.0.39
n.n.37
0.034
n 033
n n3«
0.037
0.042
0.054
0.047
n 04n
0.037
n.04i
n 035
0 035
0.035
0.040
n n35


0.0431
0.01708
39.63
D.M.
FILTER
EFFL.
n.n77
0.016
0.014
0.036
0 018
0.022
0.03.3
0.056
0.023
0.093
0.020
0 017
n n2l
n.019
0.017
0.016
n ni4
n nio
0.017
0.022
0 037
0.025
0.025
0.019
n 07n
n,ni7
0 018
0.019
0.020
n nio


0.0220
0.00827
37.59
EFFL.
TO LAKE
0 . 554
0.382
0.109
0.070
0.078
n.n66
n.nsn
0.0.36
0.025
O.n?9
0.076
n n20
n n?n
0.021
0 .021
0.018
O.OIQ
n 077
0.022
0.028
0.031
0.024
0.024
0.025
0.024
n n?n
0 nlQ
0.020
0.020
n mo


0.0614
0.1148
186.97 II
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
97 79
93.56
92.94
93.28
88 Q5
89 34
84.48
87.54
93.56
98.81
91 .98
97 . 54
93,6n
90.71
9.3.. 5.3
93.18
94 74
Q3 5n
95.25
94.06
89 85
91.05
92.35
9.3.39
I 92.69
[ 95 76
04 77
96.79
94.71
04 40


92.77
2.782
2.999
2nd STAGE
LIME
CLAR.
SI 87
79.85
86.14
69.76
86 36
85 95
82 23
72 25
79.64
8.5 . 05
86.97
85 71
88 67
88.56
8715
87.02
87 73
86 81
86.24
86.32
8.3 . 64
82 78
84.25
85.71
83 79
84 7R
84 72
83 87
82.61
83 01


83.98
4.210
5.013
DUAL-
MEDIA
FILTER
47 in
40.74
39.13
41.94
45 45
48.84
60.24
49 . 54
59.65
48 89
52 38
50 . QQ_
40 00
51 28
54.05
52.94
57 58
50 on
54.05
47.62
40.74
46.81
37.50
48.65
51 22
.51 .43
4g 57
45.71
50.00
45 71


48.76
5.662
11.61
TERTIARY
PLANT
QQ 1Q
99.23
99.40
98 82
99 1 8
99 23
98.90
98 26
99 47
99 . 39
99. 5n
99.47
Q9.56
99 48
99.62
99.58
99.7.3
9Q 57
99.70
99.57
99.02
, 99.18
99.25
99.52
99.42
99 65
	 gq cq
99.72
99 54
J)9 49


99.07
1.759
1.776
SEC. PLUS
TERT
PLANT





99.4
99. i





qq 5
99.5
99 5
99.6
99. 7
qq c;
99.6
99 6
99.2
i 99.5
99.4
99 7
99.5
99 5

99.6
99 4



99 48
0.159
0.160
        EPA-280 (Cin)
        (12-75)

-------
Tahi* F.I OnntiTiiiPcn TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Oct.
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
•>A
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE
^ ^4
4 82
A qq
4.31
A 3q
5 14
3 86
5 IT
1 7fl
1 Q7
2.49
1 28
3 06
3 25
^ 64
2 72
3 00
•z of.
2 q6
3.18
3.24
5.28




4.86
5 46
13 2
3,73
3 61

4.050
V 9 230
cc DA
SEC.
EFFL.
3 74
3 88
3 07
3.61
3 38
3. 7.3
2 68
3.22
1 68

1.46
1 .26
1 9^
2.14 -
1 C7
2. 18
2 4q
•7/17
2 =;n
2.86
5.27
3.31
2 63
2 72
2.77
•Z -7/1
.3.16
3.81
3 78
2.6n
3 29

2.9.31
0,8448
2» §2
1st STAGE
CLAR.
INF.
5,10
5.25
4 on
5.06
1 7^
4.68
4 4<;
5.25
3.17
2 2Q
2.49
1 .90
2 08
2.45
3 42
.3.10
4 OQ
-7 88
3 ^4
3 22
2.65
3.46
2.93
3 !"*•
.3 . .32
A T7
3.91
3 81
4 ^
3.78
3.46

3.614
0 9489
2« 7£>
1st STAGE
CLAR.
EFFL.
n , 234
0.241
n 222
0.219
n IP?
0 . 5.30
0,1 q>;
n iq3
n 2Q6
0,224
0.211
0.202
0 188
0.218
0 222
0.179
n 17=;
0 207
n 181
0.174
0.177
0.190
n 1Q3
n 185
0.220
n i 77
0.234
n 195
0 1QQ
0.211
0.246

0.2171
n. 06.37
9Q ^4
2nd STAGE
CLAR.
EFFL.
n n^4
0.038
n 0^4
0.032
0 028
0.027
n.n.3n
n.028
n 07i
n 04^
0.034
0 . 0.3.3
0 028
0.029
0.0.32
0.029
n n^o
0 028
0 031
0.029
0.028
0.029
0.029
0 028
0.031
n n*i
0.036
0.0.39
0 187
0.202
0.1.32

0.0464
0.4411
Qt; 06
D.M.
FILTER
EFFL.
0 01Q
0.024
0,021
0.018
0,014
0.014
0 01 R
0.014
0.052
0 031
0.024
0.023
0 01Q
0.017
0.018
0.020
0 01Q
0 016
0 016
0.018
0.016
0.016
0.017
0 01Q
0.017
n m «
0.017
0.021
0.036
0.069
0.047

0.0227
0.012.3-
c;4 40
EFFL.
TO LAKE
0 022
0.027
n 024
0.020
0 017
0.015
0 017
0.112
0 790
0.851
1.20
0.632
0 "4
0.049
0.060
0.028
n o?4
0 023
0.02.3
0.022
0.019
0.019
0.018
0 018
0.019
n m s
0.019
0.027
n n^4
0.049
0.06.3

0.1488
0.2972
199 7.3
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
95.4
95.4
QH 5
95.7
Q4 8
88.7
Qi; 6
96.3
90.7
Q0.2
91.5
89.4
91.0
91.1
9.3.5
94.2
0=; 7
«2 8
94. 9
94.6
93.3
94.5
9.3.4
Q4 1
93.4
Q"; s
94.0
94.9
qq 4
94.4
92.9

93.65
2 . 054
2. 19.3
2nd STAGE
LIME
CLAR.
85 . 5
84.2
84 7
85.4
85 . 5
94.9
84.6
85.5
76.0
80.8
83.9
83.7
85 1
86.7
85.6
8.3.8
82 Q
«A t;
82.9
83.3
84.2
84.7
85.0
84.9
85.9
82 5
84.6
80.0
6.0
4.3
46.3

78.06
20.826
26.68
DUAL-
MEDIA
FILTER
44.1
36.8
38 2
43.8
qo o
48.1
50.0
50.0
26.8
27.9
29.4
30.3
32 1
41.4
43.8
31.0
36.7
49 q
48.4
37.9
42.9
44.8
41.4
32.1
45.2
41 .9
52.8
46.2
80.7
65.8
64.4

43.48
11,637
26.76
TERTIARY
PLANT
99.6
99.5
qq 6
99.6
99 6
99.7
qq 7
99.7
98.4
98.6
99.0
98.8
qq 1
99.3
99.5
99.4
99 . 5
qq 4
99.5
99.4
99.4
99.5
99.4
99.4
99.5
99.6
99.6
99.4
99.2
98.2
98.6

99.31
0.3964
0.3992
SEC. PLUS
TERT.
PLANT
99.7
99.5
qq 6
99.6
9q.7
99.7
qq.6
99.7
—
98.4
99.0
98.2
99 4
99.5
99.3
99.3
qq.4
qq <;
99.5
99.4
99.5
99.7




99.7
99.6
99.7
98.2
98.7

99.35
0.462
0.465
EPA-280 (Cin)
(12-75)

-------
Table E-l (continued)
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Nov.
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE
3.85
4 30
3 . 54
5 fiQ
11.1
16 5
26.0
13.7




4.18
8.06
6.37
6.84
10.0
5.97
71 7
10 7
?T n
5.86
15.1
Q Ofi
4 S1^
21 .9
Q 96
is. n




11 010
v 6 6949
fiO 807
SEC.
EFFL.
2.39
7 97
3.67
3.48
4.04
2 °>4
2.91

2.67


3.35
4,]8
1.98

3.17
7 04
2 34
7 33













2.964
n 6879
33,209
1st STAGE
CLAR.
INF.
3.22
3 64
3 . 95
3 86
4.49
3 8fi
3.88
3.91
3.77
4.14
3.88
4.56
3 qi
4.13
4.76
4.97
4.75
4.85
4.57
3 Q2
3 fin
.3.28
3.9.3
4 06
3 31
4.31
3.86
3.74
3.71
4.45


4.042 •
n.71.31
5.274
1st STAGE
CLAR.
EFFL.
0.207
0 71 8
0.207
n.189
0.206
n 777
0.190
0.252
0.194
0.176
n.705
0.188
n 18fi
0.187
0.199
0.197
n 177
0.191
n 173
0 1^3
n 749
n.24i
0.235
n 777
0 iq4
0.197
0.222
0.199
0.215
0.209


0.2048
n.n208
10.171
2nd STAGE
CLAR.
EFFL.
0.082
n 077
0.075
o 077
0.066
n 073
0.076
0.102
0.071
0.071
0 . 075
n.064
n n.54
0.047
0.045
0.046
n 045
0.045
n.n.39
n 040
0.038
0.039
0.036
0.044
n.0.38
0.034
0.033
0.037
0.036
0.037


0.0544
0.0185
34.062
D.M.
FILTER
EFFL.
0.049
0 049
0.058
0 057
0.044
0 057
0.055
0.057
0.047
0.040
0.040
0.035
0.074
0.025
0.024
0.021
0.077
0.022
0.021
0.023
0.020
0.021
0.020
0.024
0.020
0.019
0.018
0.021
0.019
0.018


0.0322
0.0145
45.104
EFFL.
TO LAKE
0.039
0 044
0.047
0.046
0.045
0 055
0.050
0.058
0.047
0.041
0.041
0.0.3.3
0.027
0.024
0.024
0.022
0.024
0.023
0.028
0.024
0.021
0.021
0.022
0.025
0.021
0.023
0.019
0.023
0.022
0.020


0.0320
0.01212
37.942
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
93.6
94 0
94.8
95.1
95.4
94 1
95.1
93.6
94.8
95.7
94.7
95.9
95.2
95.5
95.8
96.0
96.3
96.1
•96.2
95.1
9.3.1
92.6
94.0
94.5
94.1
95.4
94.2
94.7
94.2
95.3


94.837
0.94522
0.99668
2nd STAGE
LIME
CLAR.
60.4
67 0
63.8
61.9
68.0
67 8
60.0
59.5
63.4
59.7
63.4
66.0
71.0
74.9
77.4
76.6
74.6
76.4
77.4
79.3
84.7
83.8
84.7
80.2
80.4
82.7
85.1
81.4
83.3
82.3


73.237
8.9600
12.234
DUAL-
MEDIA
FILTER
40.2
31 9
22.7
27.8
33.3
21 9
27.6
44.1
33.8
43.7
46.7
45.3
55.6
46.8
46.7
54.3
51.1
51.1
46.1
42.5
47.4
46.1
44.4
45.4
47.4
44.1
45.4
43.2
47.2
51.3


42.50
8.8158
0 . 20743
TERTIARY
PLANT
98.5
98 6
98.5
98.6
99.0
98 5
98.6
98.5
98.8
99.0
99.0
99.2
99.4
99.4
99.5
99.6
99.5
99.5
99.5
99.4
99.4
99.4
99.5
99.4
99.4
99.6
99.5
99.4
99.5
99.6


99.163
0.4097
0.4132
SEC. PLUS
TERT.
PLANT
98.7
98 9
98.4
99.1
99.6
99 7
99.8
99.6




99.4
99.7
99.6
99.7
99.8
99.6
99.9
99.8
99.9
99.6
99.9
99.7
99.6
99.9
99.8
99.9




99.57
0.3991
o.4ob|
  EPA-280 (Cin)
  (12-75)

-------
Table E-l (continued)
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Dec.
1973
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE

































V

SEC.
EFFL.



































1st STAGE
CLAR.
INF.
4.21
3.88
4.42
4.13
.3.06
•* 70
3 88
•* QI
3.60
4,11
4.42
3.12
3.88
416
4.04
•^ Q7
4 38
4.18
4.00
4 ?Q
5.10
4.67
4 1^
4.47
3.23
* ?n
4.71
4 ?Q
4.63
4 76
4 81

4.125
0.23373
5.6662
1st STAGE
CLAR.
EFFL.
0.226
0.705
0.222
0 740
0.717
0 2?o
0 240
n 7^
0.747
o 2«8
0.248
0.7.38
0 744
0, 768
0.374
o wi
0 288
0.783
0.320
0.356
0 . 363
0.310
0 271
0.241
0.217
0 777
0.305
0 787
0.292
0 2^1
0 ^21

0.27039
0.04222
15.614
2nd STAGE
CLAR.
EFFL.
0.037
0.037
0.036
0 040
0.035
0 O^q
0 038
0 0^7
n.nsq
0 03q
0.041
0 . 0.37
0 039
o 047
0.045
o 045
0.044
0.044
0.042
0.047
0.050
0.048
o 040
0.042
0.040
n OAA
0.069
0 07^
0.065
0 051;
0 040

0.0449
0.00940
20.935
D.M.
FILTER
EFFL.
0.018
0,018
0.016
0 Oiq
0.013
n 020
0 018
n ni 6
0.01Q
o OIQ
0.019
0 015
O.OIQ
0 O1 8
0 070
0 021
0.018
0 OIQ
0.019
0.021
0.020
0.022
Q 020
0.020
0.020
n 074
0.038
0 04^
0.031
n 024
n n7i

0.0209
0.0061
29.244
EFFL.
TO LAKE
0.019
o OIQ
0.019
0 070
0 01 1
o 01°
0 018
o 018
0 0]Q
o 017
0.019
0.01Q
0 01Q
o OIQ
0,071
0 070
0.019
0 071
0.021
0.022
0.077
0.022
0 n2n
0.020
0.021
O O74
0.040
0 0^7
0.029
o 02^
p 02^

0.0214
0.00544
25 470
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
94.6
Q4 7
95.0
Q4 7
Q2 Q
04 Q
Q3 8
Q4 0
Q1? ^
93 0
94.4
Q7 4
Q3-7
Q1* 6
97 0
Q2 4
qV4
q^ 2
92.0
91.7
92. Q
93.4
Q? R
94.6
93.3
Q7 c;
93.5
Q3 ^
9.3.7
q* Q
03 ^

93.426
0.82622
0 88436
2nd STAGE
LIME
CLAR.
8.3.6
81 Q
83.8
8^ 1
8^ Q
82 3
84.2
84 t
S1^ Q
86 5
83 . 5
84 4
84 0
a? q
86 1
8^ 1
84 7
84 4
86.9
86.8
86.2
84 5
81 Q
82.6
81.6
«/i i
77.4
74 6
77.7
81 r 1
84 7

83.306
2.7227
3 2683
DUAL-
MEDIA
FILTER
51 .3
51 ^
55.6
52 5
62 Q
48 7
52.6
c;6 8
51 ^
51 3
53 7
5Q 5
51 3
61 7
55 6
c;^ ^
59 1
56 8
54.8
55.3
60.0
54 2
c;q 2
52.4
50.0
45.4
44.9
41 1
52.3
56.4
57 1

53.819
418624
9 0347
TERTIARY
PLANT
99.6
QQ 5
qq 6
QQ 5
QQ 6
99 5
99.5
qq 6
QQ 5
QQ 5
qq 6
qq <;
qq 5
qq 6
qq 5
qq c;
qq 6
qq c;
99.5
99.5
99 6
99 5
qq i;
99.6
99.4
QQ A
9Q.2
qq 0
99 . 3
99.5
QQ 6

99.493
0.12893
0 12959
SEC. PLUS
TERT.
PLANT



































  EPA-280 (Cin)
  (12-75)

-------
Table E-l (continued)
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Jan.
1974
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE





Q qy








19,3
16.4
5 R1*
5.68
5.22
5.00
q QR
7 04
12.6
10.4
6.09
10.7

R 7q
7.41



9.094
V 4.266
46.914
SEC.
EFFL.





•j; QJ
4.63







3.73
4 ??




6 nq
4.14





5,68
3.81
3.97
3.56

4.330
0.9062
20.928
1st STAGE
CLAR.
INF.
3.82
4.18
4 61
4.14
4 ?4
3 R4
4.39
A f.n
T, qq
4 43
4 06
/] -78
4.6*
4 qa
4 03
4 43
3.71
4 ^7
5.10
1 <;q
4.61
3. 88
3.88
3.96
4.18
5.54
3.97
5 in
6.41
5.68
5.32

4.4355
0.6407
14.444
1st STAGE
CLAR.
EFFL.
0.321
0 . 349
n ^60
0.404
n 471
0 . 364
0.407
n *oq
n •?«!
0 4^4
0 334
0 °99
0.30?
0,303
0 33?
n 3?i
0.307
n 777
0.31.3
n ^iq
0.37.3
0.432
0.463
0.428
0.366
0.306
0.288
0 ?q4
0.284
0.312
0.302

0,3473
0.05158
14.852
2nd STAGE
CLAR.
EFFL.
0.052
0.049
n oqo
0.051
0.059
0.060
0.059
n 06q
n 06q
n 06q
0 065
0 05°
0.052
0.047
0.056
n.n55
0.044
0.0.35
0.045
n nm
0.059
0.071
0.080
0.074
0.065
0.058
0.063
0.075
0.087
0.090
0.079

0,0608
0.0130
21.334
D.M.
FILTER
EFFL.
0.021
0.019
0 01Q
0.023
0.029
0.046
0.022
0 073
0.074
0,073
0 024
0 019
0.021
0.018
0.074
0.074
0.021
0.014
0.019
0 070
0.023
0.029
0.029
0.025
0.021
0.023
0.026
0.038
0.048
0.048
0.045

0,0261
0.009K
3b. Ibb
EFFL.
TO LAKE
0.021
0.002
0 07?
0.028
0.037
0.075
0.023
0:074
o.o??;
0.074
0,074
0.022
0.072
0.020
0.025
0.025
0.019
0.022
0.021
0.07.3
0.027
0.031
0.029
0.024
0.024
0.021
0.023
0.040
0.046
O.Q46
0.043

0,0261
0.00875
33.5by
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
91.6
91.6
92 2
90.2
90.1
90.5
90.7
91 .3
90.4
90.9
qi 8
93.0
93.5
93.4
91.8
92 7
91.7
93.6
93.9
91 .1
91.9
88.9
88.1
89.2
91.2
94.5
92.7
94.2
95.6
94.5
94.3

91.97
1,804
1.Q61
2nd STAGE
LIME
CLAR.
83.8
86.0
86.1
87.4
86.0
83.5
85.5
83.7
81 .9
82.9
80. 5
82.6
82.8
84.5
83.1
82.9
85.7
87.4
85.6
84.0
84.2
83.6
82.7
82.7
82.2
81.0
78.1
74.5
69.4
71.1
73.8

82.232
4,453
	 5 4151
DUAL-
MEDIA
FILTER
59.6
61.2
62.0
54.9
50.8
23.3
62.7
64.6
65.2
66.7
6.3.1
63.5
59.6
61.7
57.1
56.4
52.3
60.0
57.8
60.8
61.0
59.2
63.8
66.2
67.7
60.3
58.7
49.3
44.8
46.7
43.0

57.548
8.973
15.592
TERTIARY
PLANT
99.4
99.5
99.6
99.4
99.3
98.8
99.5
99.5
99.4
99.5
99.4
99.6
99.5
99.6
99.4
99.5
99.4
99.7
99.6
99.4
99.5
99.2
99.2
99.4
99.5
99.6
99.3
99.2
99.2
99.2
99.2

99,403
0.18K
0.182'
SEC. PLUS
TERT.
PLANT





99.5








99.9
99.9
99.6
99.8
99.6
99.6
99.6
99.6
99.8
yy.b1
99.7
99.8

99.6
99.4



99,68
0,147
0.148
  EPA-280 (Cin»
  (12-75)

-------
Table E-l (continued)
TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Feb.
1974
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV
TOTAL PHOSPHORUS CONTRATION - mg/l
RAW
WASTE

9.83
9.32
8.01
9.79
6.12
8.37
7.22
7.15
9.28
8. 99
7.80
10.10
fi.QS
4.61
11.9
12.9
in.o
7.87
10.7
8.45
9.60
5.50
10.2
11.3
11.7
13.6
5.73




9.0007
V2.2475
24.970
SEC.
EFFL.
3.50
4.40
4.03
4.96
4.02
4.17
4.99
4.70
4.40
4.43
4.70
4.21
4.18
4.04
5.03
4.46
4.04
5.64
6.76
5.03
5.12
5.10
8.48

5.79
4.70
4.57
3.59




4.7793
1.0136
21.209
1st STAGE
CLAR.
INF.
3.61
4.40
4.45
5.54
9.54
6.51
5.86
6.34
5.82
5.86
7.42
6.79
7.44
5 . 53
8.09
6.34
5.82
8.06
6.16
9.38
7.65
5.29
5 . 50
7.24
6.11
7.48
6.80
9.61




6.5943
1.4908
22.608
1st STAGE
CLAR.
EFFL.
0.269
0.259
0.252
0.278
0.273
0.259
0.229
0.245
0.220
0.241
0.249
0.253
0.247
0.276
0.267
0.273
0.288
0.283
0.328
0.488
0.350
0.307
0.295
0.270
0.303
0.306
0.321
0.317




0.2838
0.0506
17.830
2nd STAGE
CLAR.
EFFL.
0.062
0.052
0.052
0.050
0.238
0.128
0.044
0.044
0.045
0.044
0.044
0.048
0.047
0.046
0.045
0.052
0.055
0.052
0.057
0.101
0.078
0.064
0.062
0 . 059
0.064
0.185
0.255
0.193




0.0809
0.0608
75.152
D.M.
FILTER
EFFL.
0.033
0.027
0.024
0.025
0.094
0.071
0.029
0.028
0.026
0.023
0.023
0.025
0.025
0.025
0.028
0.028
0.030
0.029
0.030
0.055
0.051
0.041
0.035
0.033
0.038
0.066
0.127
0.122




0.0425
0.0286
67.337
EFFL.
TO LAKE
0.030
0.026
0.025
0.042
0.090
0.070
0.030
0.029
0.025
0.027
0.025
0.027
0.027
0:027
0.027
0.029
0.030
0.029
0.039
0.053
0.043
0.039
0.037
0 . 036
0.039
0.088
0.127
0.088




0.0430
0.0258
59.903
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
92.5
94.1
94.3
95.0
97.1
96.0
96.1
96.1
96.2
95.9
96.6
96 . 3
96.7
95.0
96.7
95.7
95.0
96.5
94.7
94.8
95.4
94.2
94.6
96.3
95.0
95.9
95.3
96.7




95.525
1.041
1.0896
2nd STAGE
LIME
CLAR.
77.0
79.9
79.4
82.0
12.8
50.6
80.8
82.0
79.5
81.7
82.3
81.0
81.0
83.3
83.1
80.9
80.9
81.6
82.6
79.3
77.7
79.1
79.0
78.1
78,9
39.5
20.6
39.1




71.918
19.687
27.375
DUAL-
MEDIA
FILTER
46.8
48.1
53.8
50.0
60.5
44.5
34.1
36.4
42.2
47.7
47.7
47.9
46.8
45.6
37.8
46.1
45.4
44.2
47.4
45.5
34.6
35.9
43.5
44.1
40.6
64.3
50.2
36.8




45.304
6.9932
15.436
TERTIARY
PLANT
99.1
99.4
99.5
99.5
99.0
98.9
99.5
99.6
99.6
99.6
99.7
99.6
QQ.7
99.5
99.6
99.6
99.5
99.6
99.5
99.4
99.3
99.2
99.4
99.5
99.4
yy.i
98.1
98.7




99.361
0.34996
0.35221
SEC. PLUS
TERT.
PLANT

99.7
99.7
99.7
99.0
98.8
99.7
99.6
99.6
99.8
99.7
99.7
QQ 8
99.6
99.4
99.8
99.8
99.7
99.6
99.5
99.4
99.6
99.4
99.7
99.7
yy.4
99.1
97.9




99.50
0.405
0,407
   EPA-280 (Cin)
   (12-75)

-------
Table E-l (continued) TOTAL PHOSPHORUS DATA FOR 24-HOUR COMPOSITE SAMPLES
DATE
Mar.
1974
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31

MEAN
STDDE
%CV

RAW
WASTE
5.12
5,78
5.30
6.08
5.79
4.93
5 . 25
s.ns
4.54
4.47
6.65
7. 06
11.4
8.82
5,54
6,65
6.99
7.29
7.51
8.02
7.81
11.7
10.6
14.5
7.Q2
n Q
9.46
8.81
9.70
8.69
9 = 85

7.7161
" 2.5075
32-497
TOTAL PHOSPHORUS CONTRATION - mg/l
SEC.
EFFL.
4.02
4.42
4.10
5.17
4.54
3,99
4.75
4.82
3.46
3.99
4.90
4.14
4.43
4.99
4.47
5,39
4.40
4.85
4.71
4.40
4.53
4.49
4o70
3.59
5.47
fi.fi*
4.68
5.2Q
3.93
4.00
4,31

4.5664
0.62198
.3,621
1st STAGE
CLAR.
INF.
8,19
6.55
6.58
6.48
5.62
9.60
4.74
7.92
4.99
4.11
7.15
8.12
9.78
5.15
5.01
5.12
5.03
4.70
5.98
4,76
7.12
5,48
6.23
4.07
4.34
7.20
5.26
5.11
4, fin
5_^
5.17

5 . 9835
1.5200
25.404
1st STAGE
CLAR.
EFFL.
0.247
0.345
0.217
0.224
0.319
0.373
0.209
0.220
0.260
0.267
0.290
0.319
0.249
0.263
0.370
0.271
0. 285
0.307
0.270
0,259
0.280
0,265
0.269
0.263
Oo270
0.355
0.278
0.321
0.256
0.252
0.267

0.2787
0,04230
15.176
2nd STAGE
CLAR.
EFFL.
0.161
0.140
0.134
0.114
0.301
0.335
0.105
0.107
0.121
0.129
0.133
0.134
0.130
0,105
0.133
0.122
oaoo
0.086
0.084
0.082
0.072
0.069
0.069
0.129
0.263
0.308
0.272
0.146
0.132
0.131
0.124

0.1442
0,07215
50,026
D.M.
FILTER
EFFL.
0.095
0.089
0.091
0.078
0.109
0.160
0.057
0.069
0.083
0.088
0.080
0.090
0.087
0,070
0.051
0.062
0.048
0.040
0.040
0.043
0.037
0.034
0.035
0.060
0.105
0.129
0.106
0.107
0.109
0.067
0.082

0.0774
0.03002
38.760
EFFL.
TO LAKE
0.065
0.065
0.065
0.053
0.076
0.082
0.052
0.053
0.058
0.074
0.069
0.086
0.063
0.070
0.070
0.061
0.049
0.041
0.040
0.041
0.040
0.038
0.047
0.076
0.089
0.091
0.099
0.055
0.049
0.044
0.063

0.0621
0.01663
26.798
REMOVAL THRU INDICATED PROCESS - PERCENT
1st STAGE
LIME
CLAR.
97.0
94.7
96.7
96.5
94.3
96.1
95.6
97.2
94.8
93.5
95.9
96.1
97.4
94.9
92.6
94.7
94.3
93.5
95.5
94.6
96.1
95.2
95.7
93.5
93.8
95.1
94.7
93.7
94.4
95.3
94,8

95.103
1.1915
1 2528
2nd STAGE
LIME
CLAR.
34.8
59.4
38 2
4Q.]
5.6
10.2
49.8
51.4
53.5
51.7
54.1
58.0
47.8
60.1
64.0
55.0
64.9
72.0
68.9
68.3
74.3
74.0
74.3
51.0
2.6
13.2
2.2
54.5
48.4
48.0
53.6

48.803
21.196
43.431
DUAL-
MEDIA
FILTER
41.0
36.4
32.1
31 .6
63.8
52 2
45.7
35.5
31.4
31.8
39.8
32.8
33.1
33.3
61.6
49.2
52.0
53.5
52,4
47.6
48.6
50.7
49.3
53.5
60.1
58.1
61.0
26.7
17.4
48.8
33.9

44.029
11:858
26.932
TERTIARY
PLANT
98.8
98.6
98.6
98.8
98.1
98.3
98.8
99.1
98.3
97.9
98.9
98.9
99.1
98.6
99.0
98.8
99.0
99.1
99.3
99.1
99.5
99.4
99.4
98.5
97.6
98.2
98.0
97.9
97.6
98.7
98.4

98.655
0.52079
052789
SEC. PLUS
TERT.
PLANT
98.1
98.5
98 ,3
98 7
98.1
96.8
98.9
98.6
98.2
98.0
98.8
98.7
99.2
99.2
99.1
99.1
99.3
99.5
99.5
99.5
99.5
99.7
99.7
99.6
98.7
98.9
98.9
98.8
98.9
99.2
99.2

98.88
0.620
0.627
EPA-280 (Cin)
(12-75)

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                   APPENDIX F
DISTRIBUTION OF OPERATION AND MAINTENANCE COSTS
                       116

-------
   CHEMICALS
UTILITIES
EQUIPMENT-
                                                                         PERSONNEL
          SUPPLIES
           FIGURE  F-l.  DISTRIBUTION  OF  OPERATION  AND  MAINTENANCE COSTS

-------
00
                                 MAINTENANCE
                                 AND BOILER
                                 OPERATOR
                 FOREMAN §
                 SUPERVISOR
                 ACCOUNTANT
                  ENGINEER
                             LABORATORY
                         AND LABORATORY -
                             SUPERVISOR
                                                                                          OPERATORS
                                     FIGURE F-2.  DISTRIBUTION OF PERSONNEL  COSTS

-------
            CARBON DIOXIDE
   OTHER
CHEMICALS

CHLORINE
SULFURIC ACID
                                                                        POLYMER
                                                                        LIME
      FERRIC CHLORIDE
                  FIGURE F-3.   DISTRIBUTION OF CHEMICAL COSTS

-------
               ELECTRICITY
    WATER

TELEPHONE
                                                        HEATING FUEL OIL
                                                        AND PROPANE
                    FIGURE F-4.   DISTRIBUTION OF UTILITY COSTS

-------
GREASE § OIL
   CUSTODIAL
    SAMPLING
                                                                            LABORATORY
                  FIGURE F-5.  DISTRIBUTION OF MISCELLANEOUS COSTS

-------
                                                           MISC.  REPAIR AND MAINTENANCE
ts)
tSJ
               EQUIPMENT
               REPAIR AND"
               MAINTENANCE
   SAFETY
   EQUIPMENT

SLUDGE TRUCK
OPERATION
                                                                           NEW EQUIPMENT
                                                                           AND STRUCTURES
                                                                              EQUIPMENT REPLACEMENT
                                                                              AND SPARE PARTS
                          FIGURE  F-6.  DISTRIBUTION OF EQUIPMENT OPERATION AND REPAIR COSTS

-------
                                       TECHNICAL REPORT DATA
                                fflease read /axructions on the reverse before completing)
|4. TITLE AND SUBTITLE

 TERTIARY TREATMENT  FOR PHOSPHORUS REMOVAL AT
 ELY, MINNESOTA AWT  PLANT, April, 1973 thru March, 1974
                                                                3. RECIPIENT'S ACCESSION-NO.
                                                                5. REPORT DATE
                                                                 March 1976
                                                                 . PERFORMING ORGANIZATION CODE
   John W.  Sheehy  and Francis  L.  Evans,  III
                                                                8. PERFORMING ORGANIZATION REPORT NO.
  9. PERFORMING ORGANIZATION NAME AND ADDRESS	
   Municipal Environmental Research Laboratory
   Office of Research and Development
   U.S.  Environmental Protection Agency
   Cincinnati,  Ohio   45268
                                                             10. PROGRAM ELEMENT NO.
                                                               1  BB033
  12. SPONSORING AGENCY NAME AND ADDRESS

   Same as  above
                                                              1. ODWCDBBOT/GRANT NO.


                                                              S-802309

                                                              3. TYPE OF REPORT AND PERIOD COVERED
                                                              "nterim 4/1/73 - 3/31/74
                                                                4. SPONSORING AGENCY CODE

                                                                iPA - ORD
  15. SUPPLEMENTARY NOTES
  IMS report discusses the  design, the  construction  and the  first year's operation of
  the 1.5 mgd tertiary treatment plant located in Ely,  Minnesota    The tertiary treat

                    ""*0   dU" the             ">"«" '-"on fro               "
   h
                                  KEY WORDS AND DOCUMENT ANALYSIS
                   DESCRIPTORS
 Sewage Treatment
 Sludge Disposal
 Phosphorus
 Chemical Removal
 Operating Costs
                 (Sewage  Treatment)
13. DISTRIBUTION STATEMENT

 Release  to  Public
EPA Form 2220-1 (9-73)
                                                b.lDENTIFIERS/OPEN ENDED TERMS
Shagawa Lake  (Minnesota)
Lime-Clarification
Dual-media Filtration
Tertiary Wastewater
Operation and Maintenance
                                             19. SECURITY CLASS (This Report)
                                              Unclassified
                                                20. SECURITY CLASS {Thispage)
                                                Unclassified
                                                                            c.  COS AT I Field/Group
                                                                              13B
                           21. NO. OF PAGES

                               133
                                                                         22. PRICE
  U.S. GOVERNMENT PRINTING OFFICE: 1976-657-695/5371 Region No. 5-11

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