WATER POLLUTION CONTROL RESEARCH SERIES • 11023 FDD 07/71
 Demonstration of Rotary Screening
   For Combined  Sewer Overflows
ENVIRONMENTAL PROTECTION AGENCY • RESEARCH AND MONITORING

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          WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes
the results and progress in the control and abatement
of pollution in our Nation's waters.  They provide a
central source of information on the research,  develop-
ment, and demonstration activities in the Water Quality
Office, Environmental Protection Agency, through inhouse
research and grants and contracts with Federal, State,
and local agencies, research institutions, and industrial
organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Head, Project Reports
System, Office of Research and Monitoring, Environmental
Protection Agency, Room 801, Washington, B.C. 202^2„

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             DEMONSTRATION OF ROTARY SCREENING




                              FOR




                  COMBINED  SEWER OVERFLOWS
                               For




              ENVIRONMENTAL PROTECTION AGENCY
                               By




                 CITY OF PORTLAND,  OREGON




                DEPARTMENT OF PUBLIC WORKS




              BUREAU OF  SANITARY ENGINEERING
                     Program No.-11023  FDD




               Contract  1$-12-128 Modification No.  7




                            July, 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price 66 cents

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                      EPA Review Notice
This report has been reviewed by the Water Quality Office and
approved for publication.  Approval does not signify that the
contents necessarily reflect the views and policies of the
Environmental Protection Agency, nor does mention of trade names
or commercial products constitute endorsement or recommendation
for use.
                                  ii

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                           ABSTRACT
The objective of this demonstration was to determine screen durability,
solids removal, COD removal, and hydraulic efficiency of rotary fine
screening of storm-caused combined sewer overflows.

2300 gpm were evenly distributed to a 60 inch diameter rotating (55 rpm)
screen cage holding 18 ft^ of 165 mesh stainless steel screens (105 mi-
cron opening, 47.1 percent open area).  During a screening cycle a
concentrate sensor stopped the sewage pumps, ending the screening phase
and initiating a 30 second cleaning phase during which the screens were
automatically washed.  At the end of the cleaning phase the pumps re-
started automatically and a new cycle began.

Performance on storm-caused combined sewage flow averaged 54.8 percent
removal of settleable solids, 26.6 percent removal of suspended solids,
and 15.5 percent removal of COD.  Duration of the screening phases aver-
aged 14.6 minutes with average hydraulic efficiencies dropping from
0.880 to 0.668.

The ultimate screen life varied from a minimum of 190.5 hours to a maxi-
mum of 516 hours with an average of 346.  Screens required an average
of 3.5 repairs during this life.  (Schmidt - Portland).
                             iii

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                      TABLE  OF CONTENTS


SECTION                    TITLE                          PAGE

            ABSTRACT	-	___    in

            TABLES ------------- 	    vii

            FIGURES -	-	      ix

   1        CONCLUSIONS ---- 	       1

   2        RECOMMENDATIONS  ------------        3

   3        INTRODUCTION  -  	 ______       5

            Combined Sewage-Stormwater Overflow - - -       5



   4        DEMONSTRATION PROCEDURE ---------       7

            Site Description -------------      7

            Screening Plant Layout ----------      7

            Description and Operation of
            Screening Equipment ------------     7

            Sampling Program -------------     n

            Observations ---------------     n

   5        MODE OF OPERATION ------------      13

   6        DISCUSSION OF RESULTS 	      15

   7        ACKNOWLEDGMENTS	---      2?

   8        GLOSSARY --	_--       35

   9        APPENDICES	-	--        39

            Screen Cleaning Agents ---------        tyO
            Data Presentation ------------       Ul
            Supplemental Data ------------      52
            Detailed Methods of Analysis -------     133
            Screen Life - High Velocity	-       51*
            Screen Life - Low Velocity --------      '35
                             v

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                      TABLES



NUMBER                      TITLE                         PAGE

  1            DETAILED  SAMPLING  PROGRAM 	       12

  2            HYDRAULIC EFFICIENCY 	        16

  3            SCREEN LIFE  ------------       17

  4            REMOVAL RATES/RAIN CAUSED FLOW (3 MGD)    30

  5            REMOVAL RATES/DRY  WEATHER FLOW (3 MGD)    31

  6            REMOVAL RATES/RAIN CAUSED FLOW (2.5 MGD)  32

  7            REMOVAL RATES/DRY  WEATHER FLOW (2.5 MGD)  33

  8            REMOVAL RATES/DRY  WEATHER FLOW            31*
               HIGH VELOCITY  (3 MGD)  --------
                             Vll

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                         FIGURES


NUMBER                      TITLE                        PAGE

  1      GENERAL LAYOUT, SULLIVAN GULCH PUMP STATION
         AND SCREENING FACILITY ---- 	      9

  2      SAMPLING DIAGRAM 	 	     18

  3      SCREENING UNIT ---	--     19

  4      SCREENING CYCLE --------------      20

  5      RAINFALL PORTLAND, OREGON - 1970 ------     2l

  6      FLOW CHART 	 ___________     22

  7      FLOW CHART -----------------     23

  8      BfflOFF CONE STREAM FLOW COMPARISONS - - - -      24

  9      TYPICAL SCREEN FAILURES 	      25
                               IX

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                         SECTION 1

                        CONCLUSIONS
1.  Effective screening of storm caused combined sewage overflow is
    reduced substantially in the presence of oil and grease.  Fre-
    quent backwashing is required to return the screens to their
    original capacity.

2.  Paint has a detrimental effect on hydraulic efficiency and only
    after hand application of concentrated cleaner, Zep 9658, could
    the screens be returned to normal efficiency.

3.  Screen failures were attributable to two causes, physical break-
    down and puncture.

4.  At low velocity an average screen was repaired 3.5 times before
    ultimate failure.  At high velocity an average screen was repaired
    2.3 times before ultimate failure.

5.  Alkaline, acidic, and alcoholic agents did not adequately clean the
    screens.  Chloroform, solvent parts cleaner, soluble pine oil,  Zif,
    Formula 409, and Vestal Eight offered limited effectiveness.   Zep
    9658 cleaned the screens effectively but it should be noted that
    water quality implications were not determined.

6.  Appreciable quantities of frothy floating oil were noted in the
    relatively quiescent baffled trough which served as an effluent
    channel.
                                  - 1 -

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                       SECTION 2

                    RECOMMENDATIONS
1.  It is recommended a study be made to determine hydraulic effici-
    ency of the screens at pre-determined grease loadings.   Such a
    study would facilitate predicting hydraulic performance of screen-
    ing equipment when grease loading of the sewer is known.

2.  It is recommended a study be made for finding an economical screen
    cleaning agent, one which would be environmentally acceptable when
    discharged into a receiving water.

3.  It is recommended a study be made to find a practicable method to
    skim the oil from the screened effluent in the effluent channel
    where appreciable quantities of frothy floating oil were observed
    passing over the weir into the receiving water.
                            - 3 -

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                          SECTION 3

                        INTRODUCTION


COMBINED SEWAGE STORMWATER OVERFLOW
The majority of the existing sewers in the City of _Por_tland,
carry combined storm and sanitary flows.  Only three timelTaverage dry
weather flow reaches the sewage treatment plant.  The storm caused flow,
above three times average flow, bypasses to the receiving streams there-
by causing pollution of the water course.  To correct this condition,
separate storm and sanitary sewers would be required.

A method proposed to reduce the cost of separate sewers is the instal-
lation of high-rate, fine mesh screening units on outfall sewers to
intercept and provide primary treatment of the storm overflow.  The
feasibility of this method has been researched at this location prior
to this study.  It was the objective of this test period to determine
ultimate screen life, solids removal efficiency, C.O.D. removal effic-
iency and hydraulic efficiency of the SWECO screening equipment at the
rate of 3.3 MGD during storm flow conditions.

For storm water testing of the screenings unit, it was assumed that a
50 percent increase of the recorded average daily flow at the Sullivan
Sewage Pumping Station, would be considered storm caused flow.

Monthly rainfall records for the period of operation are shown in figure
No. 5.
                               - 5 -

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                        SECTION 4

                 DEMONSTRATION PROCEDURE
SITE DESCRIPTION
The screening facility is located adjacent to the Sullivan Sewage
Pumping Station in Portland, Oregon.  The Sullivan Station serves a
drainage basin of approximately 25,000 acres of Portland's metro-
politan area from which it pumps up to 53 (MGD) million gallons a
day.  This area is mainly residential with approximately 30,000
single-family residences within its boundaries.  The usual services
are available within this area to support the population.  Paint and
automobile related industries are well represented in this area as
indicated by their waste products frequently visible in the screened
effluent channel.  Since these are combined sewers, the usual undesir-
able amounts of oils and fats are present in varying amounts.  During
prolonged rainy periods, these amounts are, understandably, less con-
centrated.  The 72-inch interceptor sewer has a capacity upwards of
59 MGD.  The Sullivan Pumping Station is adequately sized to handle the
flow without by-passing.

The flow to the screening facility was pumped from the Sullivan Pump
Station by-pass channel at all levels of flow into the station.

SCREENING PLANT LAYOUT

Figure 1 illustrates the layout of the screening facility adjacent to
the Sullivan Sewage Pumping Station.  Combined sewage flows to the
Sullivan Station through a 72-inch horseshoe interceptor sewer.  The
flow enters the by-pass chamber through a coarse bar screen before
reaching the screening facility pumps.  The two vertical turbine pumps
are capable of lifting combined sewage flow at the rate of 5.6 MGD.

In a typical installation on an outfall sewer, the flow passing through
the screens would pass to a receiving stream after disinfection.  The
retained flow would be returned to an interceptor sewer.  In this demon-
stration installation, both flows are returned to the Sullivan Pumping
Station.

DESCRIPTION AND OPERATION OF SCREENING EQUIPMENT

Figures 3 and 4 show section s of the SWECO screening unit.  This unit
stands 69 inches high with an outside diameter of 84 inches.  The flow
enters near the bottom of the unit and passes up through a pipe in the
center of the unit onto a horizontal distribution dome.  This flighted
dome spreads and directs the flow downward against the inner top sur-
face of the screens.  The manufacturer reports an impingement velocity
                             - 7 -

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of approximately 15 feet per second at the screen.  This flow ac-
tion together with the centrifugal force resulting from the rota-
tion of the screen cage and the characteristics of the influent
determine the percentage of the flow through the screen and that
concentrate flow retained inside the screen.  The unit is equipped
with a cleaning device which activates when the concentrate flow
reaches a predetermined level.  Hot water (170 degrees F) from a
commercial water heater and tar and asphalt remover, Zep 9658,
were used to clean the screens.  The cleaner was injected into the
hotwater piping with a positive displacement pump at dilutions
varying with the consistency of the sewage.   During the cleaning
phase, the pump stops and the screen cage continues to revolve at
55 rpm while spray nozzles, located outside the screens, blast
solids and grease back into the concentrate bowl, then the inside
nozzles operate with each set alternating twice during the 30 sec-
ond cleaning phase.  This cleaning returns the screens to their
initial hydraulic capacity except when materials like paints and
heavy asphalts are present.  When such materials are present, the
screens must be cleaned manually with concentrated cleaner.  The
materials which cannot pass through the 105 micron screens are con-
tained and drop down inside of the screens to a concentrate bowl
located below the screen cage and are discharged by gravity.

The screened effluent is collected in a concentric annular chamber
box at the bottom of the unit.  The screen cage drive is located at
the top of the screening unit and is driven at 55 rpm by a 5 HP
induction motor.
                               -  8

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                                SULLIVAN
                                GULCH
                                PUMP
                                STATION
SCALE-l"= 20
 2,000 G.RM. VERTICAL
 TURBINE  PUMPS
 24 INCH DIAMETER
 DISCHARGE
 DISCHARGE
 CHANNELS
 SCREENING
 FACILITY
                               SULLIVAN
                               GULCH
                               SCREEN
                               BUILDING
12 INCH  INFLUENT PIPE

SCREEN

SCREENINGS DISCHARGE



72 INCH  HORSESHOE TRUNK
                             FIGURE  I
                         GENERAL LAYOUT
                  SULLIVAN GULCH PUMP STATION
                      AND SCREENING  FACILITY
                        PORTLAND.OREGON
                           -  9  -

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                          SAMPLING PROGRAM
Three grab samples of equal volume were taken during a one hour
time period at twenty minute intervals to make up a one hour
composite sample.  The influent samples were taken from a one
inch line attached to the influent supply pipe.  The effluent
samples were taken at the sampling point provided for on the
screening unit.  Table 1 is a summary of the sampling program.

A schematic diagram of the screening facility, the process streams
and the observations made on each stream are shown on figure 2.
                               - 11 -

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OBSERVATIONS
SETTLEABLE SOLIDS
SUSPENDED SOLIDS
COD
FLOW RATE
BACKWASH FREQUENCY
SCREEN LIFE
BOD
TOTAL SOLIDS
VOLATILE SOLIDS
CHLORINE REQUIREMENT
GREASE
PROCESS STREAM
Influent and screened
effluent
Influent and screened
effluent
Influent and screened
effluent
Screened effluent and
solids concentrate
_ _ _
- - -
Influent and screened
effluent
Influent, effluent,
concentrate
Influent, effluent,
concentrate
Influent, effluent
Influent, effluent,
concentrate
SAMPLE FREQUENCY [
twice/day
twice/day
twice/day
continuously
continuously
- - -
8nee/week
once /week
once /week
twice/day
once /week
ANALYTICAL METHOD
Appendix page 83
Wyckoff, "Rapid Solids Determination
using Glass Fiber Filters", Water
and Sewage Works, June 1964.

Jeris, "A Rapid COD Test" Water and
Wastes Engineering, May 1967.

recorder
recorder
Visual observation and log
Standard Methods, 12th Ed.

ii M ii it
it ii n ii
Appendix page 83
Appendix page 83
1- A sample is a  one-hour composite
  consisting of  three grab samples
          TABLE  I
DETAILED  SAMPLING  PROGRAM

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                          SECTION 5

                      MODE OF OPERATION
During the testing program the machine was in operation under test
conditions for a total of 914 hours.  The first 76 hours the screen
cage was rotated at 65 rpm.  The 3 MGD flow was fed to the unit at
high velocity  (the velocity was not determined).  The high velocity
was accomplished by placing an extension piece on the inlet pipe and
tightening down on a movable deflection plate thereby decreasing the
flow area.

It was discovered that general screen life was not acceptable under
these operating conditions; therefore, the screen cage was reduced
to 55 rpm, the extension piece and deflection plate were removed and
the flow reduced to 2.5 MGD.  These low velocity conditions were main-
tained for a total of 188 hours.  During the remaining 650 hours, the
machine was operated at 3 MGD and the screen was rotated at 55 rpm
without the extension piece and high velocity plate attached.

It should be understood that process stream flows are approximations
only and may range as follows:  3 MGD (high velocity) varied between
3.1 MGD and 3.8 MGD, 3 MGD (low velocity) varied between 3.2 MGD and
3.6 MGD, 2.5 MGD (low velocity) varied between 2.5 MGD and 3.3 MGD.
Actual flows are dependent on the length of the screening cycle.

During the testing program, the screens were inspected about once every
two hours for  failures.  This was done by shutting the machine off and
observing the  screens through the window or the opening provided in the
top of the machine while turning the screen cage by hand.  Shining a
light on the screens made any holes or rips quite visible.  If a screen
developed a large rip (4" or larger) it could usually be detected by
the change it  caused in the flow pattern on the window while the machine
was running.

Screens were patched with epoxy glue; and after mastering the repair
technique, the screens can be back in operation within an hour after
they have been removed.

During the 914 hours of operation, the main bearing required lubrica-
tion three times.  This was accomplished by lifting the hinged motor
cover to expose the grease fitting and could be done in five minutes.
                             -13  -

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                      SECTION 6

                DISCUSSION OF RESULTS
The results of the EPA Research and Development Project  ("Rotary
Vibratory Fine Screening of Combined Sewer Overflows", Program
11023 FDD) by Cornell, Howland, Hayes and Merryfield, indicated
that screen life was quite short and that testing under  this con-
tract should include screen durability tests under rain  caused com-
bined sewer overflows.

Preliminary to the final testing program, the screen rotation was
set at 65 RPM and the sewage inflow pipe below the distribution pan,
was extended for the purpose of increasing flow velocity.  It was
hoped that this increased velocity would increase hydraulic perform-
ance.

The combination of the 65 RPM screen speed and the high  velocity
sewage flow proved to be disastrous to general screen life.

The screen velocity was reduced to 55 RPM and the extension fitting
on the inflow pipe was removed.  The flow was also reduced to approxi-
mately 2.5 MGD.  After considerable testing it became apparent that
the high velocity of the screen and the increased velocity through the
extension fitting were primarily responsible for the short screen life
and that the flow could again be increased to 3 MGD without detriment.

Final testing of the screening unit was conducted at the lower velocity
inflow at 3 MGD with a screen speed of 55 rpm.

The results of the screen life tests are shown on Table No. 3.
                             - 15  -

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OPERATING CONDITIONS
AND NUMBER
OF OBSERVATIONS
3 MGD DRY
20 OBSERVATIONS
HIGH VELOCITY2
2.5 MGD DRY
31 OBSERVATIONS
LOW VELOCITY 2
2,5 MGD RAIN
6 OBSERVATIONS
LOW VELOCITY
3 MGD DRY
20 OBSERVATIONS
LOW VELOCITY
3 MGD RAIN
26 OBSERVATIONS
LOW VELOCITY
HYDRAULIC EFFICIENCY1
AT START OF
•SCREENING PHASE
MEAN

0.848
0.833
0.822

0.878

0.880

MIN.

0.892
0.873
0.843

0.915

0.920

MAX.

0.805
0.764
0.804

0.840

0.837

HYDRAULIC EFFICIENCY
, At . END OF,
SCREENING PHASE
MEAN

0,768
0.659
0.670

0.750

0.768.

MIN.

0.8-11
0.773
0.688

0.900

0.894

MAX.

0.733
0.570
0.617

0,656

0.650

SCREENING PHASE
LENGTH IN MINUTES
MEAN

8.0
9.6
9.6

11.2

14.6

MIN.

2.8
4.5
5.0

4.0

4.0

MAX.

25.0
25.0
20.0

40.0

56.0

1- SEE  GLOSSARY
2- SEE GLOSSARY
                                              TABLE  2
                                        HYDRAULIC  EFFICIENCY

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FLOW AND OPERATING CONDITIONS
3.1 - 3,8 MGD FLOW
HIGH VELOCITY 65 RPM
18 SCREENS TESTED
2.5 - 3.6 MGD FLOW
LOW VELOCITY 55 RPM
17 SCREENS TESTED
INITIAL SCREEN LIFE
(HRS.)
Ave.
20.5
233.2
Min.
1.8
32
Max.
35.5
336.8
NUMBER OF REPAIRS
Ave.
2.3
3.5
Min.
0
0
Max.
7
10
ULTIMATE SCREEN
LIFE (HRS.) 1
Ave.
34.3
346.
Min.
16.5
190.5
Max.
95.3
516.
1- The ultimate screen life  as  reported above is actual running hours of the screens,  and  the  life of an indivi-
   dual screen ended only when  it  could no  longer be successfully repaired.   See Appendix  .
                                                  TABLE 3
                                               SCREEN   LIFE

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                                 -SCREENING UNIT
CO

I
                                                            EFFLUENT
                            SAMPLE
                            POINTS
           WASH WATER
           EQUIPMENT
SOLIDS ( SUSPENDED
    AND SETTLEABLE )
C.O.D.
                                                         REQUIREMENT
                        COMBINED
          SCREENED SOLIDS
                                   OVERFLOW  INFLUENT

                                    SOLIDS(SUSPENDED
                                        AND SETTLEABLE)
                                    C.O.D.
CONCENTRATE
                                    CU REQUIREMENT
            COMBINED
          SEWAGE FLOW
                                                            SULLIVAN GULCH
                                                            PUMPING STATION
                                                                    INTERCEPTOR  SEWER  TO
                                                                    SEWAGE  TREATMENT PLANT
                                                  FIGURE 2
                                                   TYPICAL
                                  COMBINED  SEWAGE  OVERFLOW SCREENING
                                             SAMPLING DIAGRAM

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              HINGED  COVER
COLLAR SCREEN DRIVE
SYSTEM HOUSING
INFLUENT  DISTRIBUTION PAN



REMOVABLE SCREEN PANELS


ACCESS  FOR SAMPLING
CONCENTRATE
DISCHARGE
               ROTATING  SCREEN CAGE
                                                                       LIFTING LUGS
                    INFLUENT
                                                                    CLEAN BACKWASH
                                                                    SPRAY LINES
                                                                CONCENTRATE COLLECTOR

                                                              EFFLUENT  COLLECTOR
                               ' EFFLUENT
                               DISCHARGE
SPLASH-BACK
                                     FIGURE  3
                     SWECO  WASTEWATER CONCENTRATOR
            This unit stands 69 inches high with an outside diameter of
            84 inches.  The flow enters near the bottom of the unit and
            passes up through a pipe in the center of the unit onto a
            horizontal distribution dome.  This flighted dome spreads and
            directs the flow downward against the inner top surface of the
            screens.  The manufacturer reports an impingement velocity of
            approximately 15 feet per second at the screen.  This flow ac-
            tion together with the centrifugal force resulting from the
            rotation of the screen cage and the characteristics of the in-
            fluent determine the percentage of the flow through the screen
            and that concentrate flow retained inside the screen.
                                   - 19

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                                        INFLUENT FLOW
                                        AUTOMATIC VALVE
          SCREENED EFFLUENT
 Influent  flow valve  open:   flow continues until the
 pre-determined maximum concentrate level is reached,
 (Monitored by Sensor)
CONCENTRATE
FLOW SENSOR
 Influent flow valve  closes:   Concentrate  flow has
 reached  pre-determined maximum  level.   Cleaning
 phase is then  initiated.
                                           CONTROL PANEL

                                              IP .
  Cleaning phase:  The screen  cage  continues  to re-
  volve during the 30-second cleaning  phase.   First
  the outside nozzles spray, then  the  inside,  with
  each set operating twice during  the  phase.  Follow-
  ing the cleaning, the influent flow  valve automat-
  ically opens and the screening cycle is  repeated.

                    FIGURE  4
                 SCREENING  CYCLE
               - 20

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JAN. FEB. MAR. APR. MAY JUNE JULY
     MULTI-YEAR
     MONTHLY AVERAGE
MONTHLY TOTAL
                 FIGURE 5
                 RAINFALL
             PORTLAND,OREGON
             - 21 -

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•SCREENED EFFLUENT FLOW LEVEL
-SOLIDS CONCENTRATE  FLOW LEVEL
                   BEFORE CLEANING PHASE - SCREEN BLINDING
                    AFTER CLEANING PHASE-BACK TO NORMAL
                      FIGURE 6
                   INDICATION  OF
        LOW SOLIDS AND LOW GREASE LOADINGS
              OVER FOUR-HOUR  PERIOD
                    - 22  .

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SCREENED EFFLUENT FLOW LEVEL
-SOLIDS CONCENTRATE FLOW LEVEL
                  -BEFORE CLEANING PHASE - SCREEN BLINDING
                 y-AFTER CLEANING PHASE - BACK TO NORMAL
                      FIGURE  7
                    INDICATION  OF
           SEWAGE CHARACTERISTIC  CHANGES
               OVER  FOUR-HOUR PERIOD
                         - 23"

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      INFLUENT COMBINED
          SEWAGE


        SCREENED EFFLUENT-
           FIGURE  8
    IMHOFF  CONE COMPARISON
              OF
SCREENED AND UNSCREENED FLOWS

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                                            NEW  SCREEN
-TYPICAL SCREEN FAILURE
 NOTE PRIOR  REPAIR TO
 PROLONG ULTIMATE  SCREEN
 LIFE .
                                                     -SCREEN STRESS
                                                      BREAK  REPAIRED
                             FIGURE   9
                         TYPICAL  SCREENS

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                          SECTION 7

                      ACKNOWLEDGMENTS



The City of Portland, Oregon acknowledges SWECO, INC.  of Los Angeles,
California, for their cooperation and assistance in conducting this
study for the Environmental Protection Agency.

Donald Hernandez, Project Officer - E.P.A.

City of Portland:

Joseph P. Niehuser, Chief, Bureau of Sanitary Engineering

H. Tim Neketin, Chemist

Harry K. Dennis, Jr., Technical Investigator
                            - 27  -

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TABLES
   29

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                                      REMOVAL RATES RAIN CAUSED FLOW




                                             26  OBSERVATIONS




                                                  3 MGD
CHARACTERISTIC

SETTLEABLE SOLIDS
mg/L
SUSPENDED SOLIDS
mg/L
COD mg/L
INFLUENT
MEAN

59.5
111.8
180.5
MIN.

22
54
79
MAX.

180
246
303
EFFLUENT
MEAN

28.2
81.6
152.2
MIN.

2
36
60
MAX.

120
192
281
PERCENT REMOVAL1
MEAN

54 8
26.6
15.5
MIN.

16.1
6.1
5.9
MAX.

92.5
56.4
31
1-  26  OBSERVATIONS  (SEE APPENDIX)
                                                    TABLE  4

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                                      REMOVAL RATES  DRY-WEATHER FLOW




                                              20  OBSERVATIONS




                                                      3 MGD
CHARACTERISTIC
SETTLEABLE SOLIDS
mg/L
SUSPENDED SOLIDS
mg/L
COD mg/L
INFLUENT
MEAN
46.4
85.3
217
MIN.
28
54
67
MAX.
92
128
303
EFFLUENT
MEAN
17.1
57.6
188.8
MIN.
6
38
57
MAX.
44
82
272
PERCENT REMOVAL1
MEAN
62.7
31.9
13.5
MIN.
12
10.7
5.3
MAX.
85.7
45.7
27.8
i- 20 OBSERVATIONS (SEE APPENDIX)
                                                   TABLE   5

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                                        REMOVAL RATES RAIN CAUSED FLOW




                                                6  OBSERVATIONS




                                                    2.5 MGD
CHARACTERISTIC

SETTLEABLE SOLIDS
mg/L
SUSPENDED SOLIDS
mg/L
COD mg/L
INFLUENT
MEAN

65

111
273.5
MIN.

38

70
248
MAX.

176

224
299
EFFLUENT
MEAN

26.3

77.7
207.5
MIN.

0

52
182
MAX.

82

136
233
PERCENT REMOVAL l
MEAN

64.2

28.0
224.1
MIN.

35

20
22.1
MAX.

100

39.3
26.6
1- 6 OBSERVATIONS (SEE APPENDIX)
                                                     TABLE   6

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                                                REMOVAL RATES DRY-WEATHER FLOW




                                                        31 OBSERVATIONS




                                                            2.5 MGD
uo
uo
CHARACTERISTIC
SETTLEABLE SOLIDS
mg/L
SUSPENDED SOLIDS
mg/L
COD mg/L
INFLUENT
MEAN
68.8
113.8
284.4
MIN.
30
62
160
MAX.
182
246
405
EFFLUENT
MEAN
21.9
71.6
244.3
MIN.
6
38
123
MAX.
66
134
347
PERCENT REMOVAL l
MEAN
68.8
35.9
14.7
MIN.
39.4
20
7.1
MAX.
93.3
53.6
23.1
       1-  31  OBSERVATIONS (SEE APPENDIX)
                                                           TABLE   7

-------
                                                REMOVAL RATES DRY-WEATHER FLOW



                                                        20 OBSERVATIONS


                                                      3 MGD high velocity
uo
Xr
CHARACTERISTIC
SETTLEABLE SOLIDS
mg/L
SUSPENDED SOLIDS
mg/L
COD mg/L
INFLUENT
MEAN
74.8

124.1
350
MIN.
46

86
24
MAX.
134

186
532
EFFLUENT
MEAN
32.3

88
305
MIN.
8

60
206
MAX.
64

122
502
PERCENT REMOVAL1
MEAN
57.5

28.7
12.9
MIN.
33.3

16.1
5.6
MAX.
82.6

38.1
24.7
         1- 20 OBSERVATIONS  (SEE APPENDIX)
                                                            TABLE   8

-------
                          SECTION 8

                          GLOSSARY
AVERAGE DAILY DRY WEATHER FLOW - The flow from a complete sewer system,
or a defined portion thereof, measured in total gallons throughout a
24-hour period  (expressed in millions of gallons per day).

BAR SCREEN - A  screen composed of parallel bars, either vertical or
inclined, placed in a waterway to catch debris, and from which the
screenings may  be raked.  (Also called a rackX

BOD5 - Five-day Biochemical Oxygen Demand is that amount of oxygen
utilized in aerobic decomposition of a waste material during a five-day
incubation at constant temperature.

CLEANING PHASE  - That part of the screening cycle during which the sewage
pumps are off and the screens are being automatically washed.

COD - Chemical  oxygen demand is a measure of the oxygen necessary to
stabilize most  of the oxidizable compounds in a waste.

COMBINED SEWER  SYSTEM - A system of sewers receiving both surface runoff
and sewage.

COMPOSITE SAMPLE - Integrated sample collected by taking a portion at
regular time intervals, with sample size varying with flow; or taking
uniform portions on a time schedule varying with the total flow.

CONCENTRATE - That portion of the flow (solids and liquid) which does not
pass through the screens.

DISSOLVED OXYGEN - Usually designated as D.O.  The oxygen dissolved in
sewage or other liquid usually expressed in milligrams per liter or per
cent of saturation.

DISSOLVED  SOLIDS -  Solids which are present in solution.

EFFICIENCY - The ratio of the actual performance of a device to the
theoretically perfect performance sometimes expressed as a percentage.

EFFLUENT - Liquid flowing out of a basin or treatment plant.

EFFLUENT WEIR - A weir at the outflow end of a sedimentation basin or
other hydraulic structure.

GENERAL SCREEN  LIFE - Collective term used in referring to any or all of
ultimate, initial, or service screen lives.
                            .  - 35  -

-------
GREASE - In sewage, grease includes fats, waxes, free fatty acids,
calcium and magnesium soaps, mineral oils, and other nonfatty
materials.  Substances soluble in n-hexane.

GRIT - The heavy mineral matter in water or sewage, such as sand,
gravel, cinders, etc.

HIGH VELOCITY - The impingement velocity upon the screens when the
screen cage is rotating at 65 RPM, the extension piece coupled to
the influent line and the deflection plate is closed down over the
end of the extension.

HYDRAULIC EFFICIENCY - The ratio of screened effluent flow to influent
flow.

INFLUENT - Liquid flowing into a basin or treatment plant.

INITIAL SCREEN LIFE - The number of working hours on a screen until
it sustains its first damage, repairable or not.

LOW VELOCITY - The impingement velocity upon the screens when the screen
cage is rotating at 55 RPM, the deflection plate is raised and there
are no alterations to the influent line.

mg/L - Milligrams per liter.

MGD - Million gallons per day.
OUTFALL SEWER - The outlet or structure through which sewage is finally
discharged.

PER CENT CONCENTRATE - (100) (Concentrate Flow) / (Influent flow)

PRIMARY TREATMENT - The removal of settleable organic and inorganic
solids by the process of sedimentation.

SCREENING CYCLE - The sequential events between sewage pump start-up
and the conclusion of the cleaning phase.

SCREENING PHASE - That part of the screening cycle during which sewage
is being pumped to the screens.

SEDIMENTATION - The process of subsidence and deposition of suspended
matter carried by water, sewage, or other liquids, by gravity.  It is
usually accomplished by reducing the velocity of the liquid below the
point where it can transport the suspended material.

SERVICE SCREEN LIFE - The number of working hours on a screen between
renairs.
                               -36  -

-------
SETTLEABLE SOLIDS - That matter in sewage which will not stay in
suspension during the settling period.

SEWAGE TREATMENT PLANT - Man-made structures which subject sewage to
treatment by physical, chemical, or biological processes for the pur-
pose of removing or altering its objectionable constituents, and
rendering it less offensive or dangerous.

STORM SEWER - A sewer which carries storm water and surface water,
street wash and other wash waters or drainage, but excludes sewage
and industrial wastes. (Also called a Storm Drain).

SEPARATE SYSTEM - A sewer system comprised exclusively of sanitary
sewers which carry only sewage and to which storm water, surface water,
and ground water are not intentionally admitted; also referred to as
"sanitary system" or separate sanitary system.

SUSPENDED SOLIDS  - Non-filterable residue  (expressed in parts per
million, ppm, or milligrams per liter, mg/L).

TOTAL  SOLIDS  - The solids in water, sewage, or other liquids,

ULTIMATE  SCREEN LIFE  - The number of working hours on a screen until
it  sustains  irreparable damage.

VOLATILE  SOLIDS  - The quantity of solids in water, sewage or other
liquid lost  on ignition of the total  solids.
                             - 37  -

-------
                 SECTION 9




                 APPENDICES




                                              PAGE




SCREEN CLEANING AGENTS      	  57




DATA PRESENTATION    			59




SUPPLEMENTAL DATA    	   81




DETAILED METHOD OF ANALYSIS 	    83




SCREEN LIFE  (High Velocity)	    85




SCREEN LIFE  (Low Velocity)	   87
                      - 39 -

-------
                   SCREEN CLEANING AGENTS
Early in the program it was found that sodium hypochlorite did not
clean the screens adequately and a minor research project ensued.
Several screens were taken to the laboratory where they were wetted
and various solutions applied to them to determine the best cleaning
agent.  Concentrated sodium hydroxide, potassium hydroxide, 14% sodium
hypochlorite, acetone and chloroform were tried and only chloroform
appeared to have an affect on the screen residue.  A solvent parts
cleaner was tried under actual working conditions; it successfully
cleaned the screens but the high water temperature combined with its
volatile nature made it unacceptable.  A soluble pine oil, Zif, Form-
ula 409, Vestal Eight and a few other similar type cleaners offered
limited effectiveness.

A cleaner called Zep 9658 (designed for asphalt and tar removal) was
tried and was found to do a very good job cleaning the screens.  This
may not be the ultimate cleaner as no evaluation of its economic or
environmental implications was attempted, but it performed satisfactor-
ily at this installation and no effort was exerted to find a better
cleaner.

-------
                                                      SCREEN VELOCITY  (55 RPM)
RUN >;0.
™
WEATHER
SULLIVAN FLOW-MGD
PROCESS STREAM FLCW-MGD
I ' '
HYDRAULIC START
3 EFFICIENCY STOP
i
i
i SCREENING PHASE (MINUTES)
| 1 SETT. SOLIDS mg/L
1 « SUSP. SOLIDS mg/L
1 £j C 0 B mg/L
j CL 9 REQUIREMENT ing/L
SETT. SOLIDS mg/L
,^j SUSP, SOLIDS mg/L
-5
£| COD i«g/L
^ .. . ,
^ CL2 REQUIREMENT mg/L
| % REMOVAL SETT, SOLIDS
% JIEMOVAL SUSP. SOLIDS
1 % REMOVAL COD
1
0900
1000
Dry
24
2.8
0.754
0.659
7.5
60
88


18
46


70
47.7

2
1300
1400
Dry
24
2jB
0.764
0.598
6.1
48
90


10
54


79.2
40.0

3
0900
1000
Dry
21
2.5
0.820
0.570
9.5
56
120


28
88


50
26.7

5
1300
1400
Dry
30
3.0
0.808
0.664
4.5
50
84
252

16
54
211

68
35.7
16.3
6
0900
1000
Dry
22
2.8
0.799
0.659
9.5
112
164
405

16
76
347
I .,., .,!•_...,
85.7
53.6
14.3
7
1300
1400
Dry
27
2.9
0.811
0.665
6.1
42
80
272

24
64
239

42.8
20.0
12.1
8
1300
1400
Dry
30
2.9
0.834
0.873
6.0
64
132
396

30
102
368

53.1
23.9
7.1
10
0900
1000
Dry
20
2.8
0.842
0.623
11.5
58
106
347
14.6
8
68
289
15.0
86.2
35.8
16.7
1
11
1300
1400
Dry
25
3.1
0.834
0.653
8.0
.94
126
260

34
76
210

63.8
39.7
19.2
12
2000
2100
Dry
22
3.0
0.860
0.642
6.1
50
116


22
88

. 1
56.0
24.1
!
13
0900
1000
Dry
20
2.9
0.834
0.666
25.0
64
112
314

24
84
272

62.5
1
25.0
13.4
I
Jr

-------
SCREEN VELOCITY  (55 RPM)
f
»
Ti.\?:
<
VJtATKEK
i
SULLIVAN FLCW-MCO
PPO,.EPS f-TRr.^M FLOW-MGD
LY^RAULIC STArng/L
r1! c o r -^/L
i ^J i
, \ CI.--_3i.EQ'JIiJ2MErtT n:^/L
i r.::":r. SOLIJJS mg/L
j
i:j SJSP. SOLIDS tag/L
j^j -0-0 .tUj/L
hi ' '
~! CL-, RSQiTIRrMEHT mg/L !
» - >
% RSXCVAL SETT. SOLIDS
" REMOVAL SUSP. SOLIDS j
% PvEMOVAL COD |
16
1300
1400
Dry
30
3.1
0.814
0.659
8.0
56
80
194

.20
54
156

64.3
32.5
19.6
20
1300
1400
Dry
30
3.0
0.908
0.647
5.0
— , ,. ...
82
124


22
70


73.2
43.5

21
1700
1800
Dry
32
3.3
0.850
0.745
i
9.5
114
160


44
94


61.4
41.2

22
0800
0900
Dry
22
3.0
0.798
0.685
7.0
182
246


34
114


81.3
53.6

24
1300
1400
Dry
30
3.0
0.825
0.653
14.0
60
92


30
48


50.0
47.8

25
1700
1800
Dry
28
3.0
0.817
0.643
14.0
66
140


40
108


39.4
22.8

26
2000
2100
Dry
24
2.8
0.862
0.600
15.0
32
64


4
38


87.5
40.6

27
0900
1000
Dry
24
2.7
0.849
0.649
20.0
34
82


8
58

11.8
76.5
29.3

28
1300
1400
Dry
24
2.8
0.862
0.637
8.0
50
80

12.2
22
54
223
13.0
56
32.5
18.0
29
1700
1800
Dry
23


8.0
30
78
272
15.6
8
62


73.3
20.5

30
2000
2100
Dry
26
2.7
0.866
0.623
8.0 J
32
62


8
48


75.0
22.6


-------
SCREEN VELOCITY (55 RPM)
RIIN NO.,
§
TIME
WEATHER
^ SULLIVAN FLOW-MGD
i
1 ?.-lOCl:^S STREAM FLOW-MGD
1 HYDRAULIC START
1 EFFICIENCY STOP
| SCREENING PHASE (MINUTES)
i {
1 j | SETT. SOLIDS mg/L
^ f HJ
. (2=1 SUSP, SOLID S mg/L
[-- ?
; ^1 C 0 D nig /I'
J CL 2 REQUIREMENT ir.g/L
1 SETT. SOLIDS nig/L
« 3
H r
-------
SCREEN VELOCITY (55 RPM)



(
1
i
*
:-:c

t—
"
Ul
f-

r j
H
U-l
E
«



RUN NO.
TIME
WEATHER
SULLIVAN FLOy-MGD
PROCESS STREAM FLOW-MGD
HYDRAULIC START
EFFVOIEXCY STOP

-------
SCREEN VELOCITY (55 RPM)
RUN NO .
TIME
WEATHER
| SULLIVAN FLOW-MGD
•- — ,
8
1 PROCESS STREAM FLOW-MGD
\ HYDRAULIC START
P EFFICIENCY STOP
i
I
1 SCREENING PHASE (MINUTES)
j [ SETT. SOLIDS mg/L
j r_/l
1 r-| SUSP. SOLIDS mg/L
' £ « •
£ C C D mg/L
'"-':
1 j CL 2 REQUIREMENT mg/L
I I
SETT. SOLIDS mg/L
I
r "
^j SUSP. SOLIDS mg/L
!^| COD mg/L
Ir"1 F *
f~1 !
| W CL2 SEQUIREMRNT mg/L
I % REMOVAL SETT, SOLIDS
% REMOVAL SUSP. SOLIDS
>% REMOVAL COD
176
2000
2100
Dry
20
3.3
0.853
0.656
10.0
52
94
232
7.6
14
58
219
8.7
73.1
38.3
5.6
181
0100
0200
Dry
21
3.3
0.915
0.900
20.0
32
56
79
12.9
26
50
57
16.2
18.8
10.7
27.8
196
0100
0200
Dry
12
3.3
0.900
0.866
25.0
50
76
67
12.4
44
64
60
13.1
12.0
15.8
10.4
199
1300
1400
Dry
20
3.3
0.876;
0.746
7.5
42
74
243
12.4
6
54
234
11.0
85.7
27.0
3.7
205
2000
2100
Dry
19
3.3
0.874
0.660
15.0
32
64
170
11.1
8
38
133
8.3
75
40.6
21.8
206
0100
0200
Dry
12
3.4
0.902
0.757
10.0
92
120
152
6.6
34
68
135
9.0
63.0
43.3
11.2
210
1700
1800
Dry
20
3.4
0.886
0.744
23.0
40
78
234
38.3
14
52
213
34.8
65
33.3
9
211
2000
2100
Dry
19
3.3
0.882
0.706
10.0
52
76
217
9.6
20
46
184
11.3
61.5
39.5
15.2
215
1300
1400
Dry
30
3.2
0.862
0.732
5.0
42
70
232
9.7
10
38
208
9.3
76.2
45.7
10.3






















i
i





j
i
1
i
1
3

|

-------
                                                          SCREEN VELOCITY (55 RPM)
7 	
L
rUX NO.
TIME
WEATHER
SULLIVAN FLOW-MGD

PROCESS STREAM FLOW-MGD
HYDRAULIC START
FrFICTKN'CY STOP
SC
r
j
Hi-"
£-
HH
1:
I o
1- .
u,
iJ-t
-1
REENINC4 PHASE (MINUTES)
SETT. SOLIDS mg/L
SUE'-1. SOLIDS mg/L
CO U ™g/L
CI. o RaQU IPvEMENT mg/L
SK'iT. SOLIDS nig/L
SUSP. SOLIDS mg/L
COD rcg/'L
CL2 P^'4UIREMENT mg/L
% REMOVAL SETT. SOLIDS
% REMOVAL SUSP. SOLIDS
7. REMOVAL COD
9
0900
1000
Rain
30
3.1
0.824
0.688
8.0
54
104
248

30
82
182

44.4
21.2
26.6
i
14
1700
1800
Rain
32
3.1
0.840
0.681
9.5
38
90


0
62


100
31.1

15
2000
2100
Rain
30
2*
0.843
0.617
5.0
40
100


26
80


35.0
20.0

17
1700
1800
Rain
33
3.0
0.808
0.647
7.0
38
70


6
54


84.2
22.8

18
2000
2100
Rain
32
2.8
0.804
0.634
8.0
44
78


14
52


68.2
33.3

38
0800
0900
Rain
30
3.1
0.814
0.751
20.0
176
224
299
13
82
136
233
14.3
53.4
39.3
22.1








































































. _

















I
Xr

-------
SCREEN VELOCITY (55 RPM)
S RUN NO !
5
5
| TIME
a
I
t WEATHER
SUI.L I VAN FLOW -MGD
i
' PROCESS STREAM FLOW-MGD
| lijfORAULIC START
1 EFFICIENCY STOP
I
I
( SCREENING PHASE (MINUTES)
fl« V-.., u, --, ,«_ _.-_.... T. - ,, 	 „•.,••,.„.„,.....,„•.,....
, i ' " -...-..—.
! | SZTT SOLIDS mg/L
' H /T
5 s; SUS;' SOLIDS mg/L
8 -1-- (
! £j C 0 D mg/L
! r" I
5 ( CLo REQUIREMENT mg/L
? t "
3 j
I 1 EET'i\ SOLIDS mg/L
» i
| fcis SUSP.. SOLUS ^g/L
S -'1 /T
j r-! COD mg/L
i f^J
j L--' J
\ ^\ CL-; REQfJIRElCNT mg/L
s,.^_ _—
i ^ R£V;OV,a S'lTT. SOLIDS
L
L_. - .... , . ._
% RJ7HGv^L GJSP. SOLIDS
; .% REMOVAL C 0 D
i,_u_« -.-.—— .-.I. — in... —~.~^
124
;0900
1000
Rain
55
3.3
0.870
0.650
40.0
66
114
228
12.7
42
88
176
13.1
36.4
22.8
22.8
.
125
1900
2000
Rain
55
3.2
0.910
0.800
10.5
i i..i ,i ...M ,i. , i
28
58
172
11.6
12
46
120
14.0
57.1
20.7
30.2
130
1700
1800
Rain
55
3.3
0.878
0.732
16.5
. .. ...„ 	
54
94
211
10.3
20
66
159
10.8
63.0
29.8
24.6
131 ,
2000
2100
Rain
45
3.6
0.907
0.838
12.0
56
92
116
8.1
28
68
99
7.1
50
26.1
14.6
162
0900
1000
Rain
45
3.3
0.862
0.748
10.5
52
92
162
12.1
26
68
144
11.1
50
26.1
11.1
168
1300
1400
Rain
33
3.3
0.860
0.746
4.5
56
122
303
11.1
20
88
281
12.4
64.3
27.9
7.3
177
0900
1000
Rain
48
3.3
0.859
0.726
10.0
130
224
237
10.4
60
162
175
10.0
53.8
27.7
26.2
178
1300
1400
Rain
58
3.3
0.875
0.837
15.0
42
98
158
14.1 .
22
66
109
14.1
47.6
32.6
31.0
179
1630
1730
Rain
44
3.4
0.904
0.787
10.0
50
120
169
13.8
20
86
151
13.1
60
28.3
10.6
180
2000
2100
Rain
58
3.3
0.900
0.724
20.0
58
128
193
11.1
22
98
175
11.1
62.1
23.7
9.3
183
0900
1000
Rain
38
3.3
0.884
0.837
0.5
42
70
206
12.9
14
44
179
11.7
66.7
37.1
13.1

-------
SCREEN VELOCITY (55 RPM)
Rim NO.
TIME
1
WEATHER
SULLIVAN FLOW-MGD
PROCESS STREAM FLOW-WGD
HYDRAULIC :JTART
EFFICIENCY STOP
1
j SCREENING PHASE (MINUTES)
i , , ,. 	 	 -
1 SI/IT. SOLIDS iag/L
^ SUSP. SOLIDS nig/L
£ C 0 D rng/L
CL 2 REQUIREMENT mg/ L
SETT. SOLIDS mg/L
gj SUSP. SOLIDS mg/L
'- i
^ COD mg/L
~ CL2 REQUIREMENT tng/L
?i REMOVAL SETT. SOLIDS
7, RLMOVAL SUSP. SOLIDS
,% REMOVAL COD
184
1300
1400
Rain
38
3.3
0.857
0.755
14.0
180
246
180
14.8
120
192
162
12.9
'
33.3
22.0
10.0
185
0100
0200
Rain
54
3.3
0.866
0.904
12.0
22
54
79
10.4
2
36
70
9.6
90.9
33.3
11.4
186
1000
1100
Rain
38
3.3
0.837
0.750
4.0
80
124
80
9.4
6
54
226
9.4
92.5
56.4
8.9
190
2000
2100
Rain
36
3.5
0.899
0.742
16.5
56
134
122
10.7
14
94
109
11.1
75
29.8
10.8
191
0100
0200
Rain
48
3.3
0.878
0.797
5.5
62
98
191
9.7
52
92
148
10.4
16.1
6.1
22.5
192
0900
1000
Rain
30
3.3
0.850
0.731
6.5
32
84
187
9.7
12
62
176
9.4
62.5
26.2
5.9
193
1300
1400
Rain
50
3.3
0.884
0.739
8.0
50
88
172
13.1
36
70
121
11.4
28.0
20.4
29.6
194
1700
1800
Rain
44
3.3
0.901
0.696
56.0
82
148
155
9.7
36
100
129
10.4
56.1
32.4
16.8
195
200q
2100
Rain
40
3.5
0.904
0.810
35.6
38
84
140
13.5
16
62
114 ,
14.5
57.9
26.2
18.6
198
0900
1000
Rain
33
3.3
0.875
0.790
15.0
34
84
148
17.6
12
68
138
11.7
64.7
19
6.8
202
0900
1000
Rain
34
3.3
0.868
0.794
5.0
40.
98
215
11.1
18
72
178
10.0
55
26.5
17.2

-------
                                                    SCREEN VELOCITY (55 RPM)
"•""" 	 '""• 	 • 1
RUN NO.
TTMF
"
s
WEATHER
SULL IVAN FLOW -MGD
PROCESS STREAM FLOW-MGD
! HYDRAULIC START
EFFICIENCY STOP
1
SCREENING PHASE (MINUTES)
SETT; SOLIDS mg/L
| SUSP. SOLIDS mg/L
| £H COD mg/L
| j CL 2 REQUIREMENT mg/L
—T"1- "-"• 	 	 '•"""'
\ SETT. SOLIDS mg/L
S
| ;^| SUSP, SOLIDS mg/L
I 9! COD mg/L
i ' '
a ^
W CL2 REQUIREMENT mg/L
f ^ — 	 	 	
| % REMOVAL SETT. SOLIDS
|
! % REMOVAL SUSP. SOLIDS
•% REMOVAL COD
L™_«-",— -«-m -- 	 - 	 - 	 — - — - — •• — •• —
1
203
1300
1400
Rain
33
3.2
0.844
0.686
4.2
64
116
239
10.4
_
36
88
208
8.7
43.8
24.1
13
204
1700
1800
1
Rain
28
,3.3
0.878
0.703
20.0
96
198
248
14.2
38
138
226
9.7
60.4
29.6
8.9
208
0900
1000
Rain
: 58
3.3
0.917
0.894
15.0
42
72
70
12.1
34
64
60
12.1
19
11.1
.14.3
209
1300
1400
Rain
30
3.3
0.900
0.836.
8.0
34
68
136
12.1
14
50
125
12.1
58.8
26.5
8.1




















































































































i









I

-------
SCREEN VELOCITY (65 RFM)
RUN NO
TIME
LEATHER
SULLIVAN FLOW-MGD
PROCESS STREAM FLOW -MOD
riVUUAULIC START
EFFICIENCY STOP
SCREENING PHASE (MINUTES)
J SETT. SOLIDS mg/L
r
£ SUSP. SOLIDS mg/L
I'- COD mg/L
• s
GL 2 REQUIREMENT mg/L
SETT. SOLIDS mg/L
1
£ SUSP. SOLIDS ajg/L
• £•
£ C 0 U ^g/'L
" CT , REQUIREMENT mg/L
I z
% REMOVAL SETT. SOLUS
% EEMGVAL SUSP. SOLIDS
(
:: REMOVAL COD
1-1
0900
1000
Dry

3.8
0.848
0.785
6.0

125
246
,

99
224

c
20.8
t
8.9
1-2
1300
1400
Dry
30
3.4
0.832
0.774
3.7
76
148
310

26
110
265

65.8
25.7
14.5
1-3
0900
1000
Dry
25
3.5
0.846
0.780
12.8
46
105
356

8
72
322

82.6
31.4
9.6
1-4
1300
1400
Dry
25
3.5
0.855
0.786
5.5
75
149
301

29
119
275

61.3
20.1
8.6
1-5
0900
100
Dry
24
3.3
0.858
0.793
4.5
54
112
339

36
94
318

33.3
16.1
6.2
1-6
0900
1000
Dry
24
3.6
0.806
0.782
2.8
48
98
267

16
68
234

66.6
30.6
12.4
1-7
1300
1400
Dry
30
3.3
0.866
0.799
14.5
108
162
281

58
114
250

46.3
29.6
11.0
1-8
0900
1000
Dry
20
3.3
0.892
0.740
25.0
90
154
532
I
48
122
502

46.6
20.8
5.6
1-11
'0900
1000
Dry
32
3.6
0.836
0.761
3.3
52
86
.303

24
60
269

53.8
30.2
11.2
1-12
1300
1400
Dry
25
3.6
0.856
0.761
4.5
118
162
377

64
116
328

45.8
28.4
13.0
1-13
0900
1000
Dry
21
3.3
0.865
0.740
13.0
50
116
476

22
88
410

56
24.1
13.9

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                                                         SCREEN VELOCITY (.65 RPM)
1 	 i
RUN NO .
TIME
| WEATHER
SULLIVAN ii-LCW-MGD
•
! PROCESS STREAM FLOV-MGD
! HYDRAULIC START
I EFFICIENCY STOP
j SCREENING PHASE (MINUTES)
p.
J ] SETT. SOLIDS mg/L
\ '^\
\ 2< SUSP. SOLIDS mg/L
; /•' 5
5 £1 C 0 L mg/L
1 3
j. Hl
| | CL 2 REQUIREMENT mg/L
1 SETT. SOLIDS mg/L
g SUSP. SOLIDS mg/L
,_., 1 	 . _ 	 ... 	 , ..
£J COD mg/L
PI., j —
^1 CL-7 REQUIREMENT mg/L
i
i % REMOVAL SETT. SOLIDS
1
1 % REMOVAL SUSP. SOLIDS
| % RTMOVAL COD
i
1-14
1300
1400
Dry
22
3.3
0.850
0.758
5.0
70
118
348

30
84
302

57.1
f
28.8
•
13.2
1-15
0900
1000
Dry
30
i
3.4
0.841
0.760
10
72
96
336

38
66
253

47.2
31.2
24.7
1-16
1300
1400
Dry
30
3.4
0.841
0.733
8.1
134
186
352

60
11.6
'
291

55.2
37.6
17.3
1-17
0900
1000
Dry
22
3.5
0.832'
0.811
11.5
60
106
422

18
72
327

70
32.1
-
22.5
1-18
1300
1400
Dry
30
3.3
0.858
0.768
7.0
54
100
341

28
78
315

48
22.0
7.6
1-19
2100
2200
Dry
30
3.6
0.838
0.745
4.5
92
138
302

38
90
263

58.7
34.8,
12.9
2-2
1700
1800
Dry
21
3.3
0.884
0.791
11.5
92
122
246

28
76
211

69.6
37.7
14.2
2-3
1700
1800
Dry
25
3.3
' 0.858
0.756
3.5
54
94
504

16
60
448

70.4
36.2
11.1
2-4
2100
2200
Dry
20
3.1
0.805
'0.754
3.5
68
96
254

28
62
206

58.8
35.4
18.8
































1
i


I
Ul

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                                                     SUPPLEMENTAL DATA
1970 DATE

1
.-3
B

g
§
fa
W

W
B
z
8
z
8
5 Day BOD mg/L
Hexane Solubles mg/L

Total Solids mg/L
5 Day BOD mg/L


Hexane Solubles mg/L
Total Solids mg/L
5 Day BOD mg/L

Hexane Solubles mg/L


Total Solids mg/L
7-27
145
43

570
165


29
444
190

47


728
8-3
175
32

435
180


35
383
250

43


607
8-10
180
16

343
30


8
315
105

18


482
9-21
145
18

437
145


11
377
185

13


489
9-28
130
12.8

373
115


10.4
274
205

16


508
10-6
110
23

331
120


16
310
195

28


533
10-13

32

356



24
325


32


470
10-20
100
23

245
85


30
224






11-19
90
64

273
105


36.4
275
115

34.4


326
11-24
90
37.6

382
75


32.4
358
120

42.8


480
11-30
85


294
70


24
274
110

28


409
I
r\j
i

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                     DETAILED METHOD OF ANALYSIS


SETTLEABLE SOLIDS

1.  Determine suspended solids on a well-mixed sample.

2.  Pour approximately three quarts of well mixed sample into
    a wide-mouthed plastic gallon jug.  Depth should be at least
    20 cm, diameter at least 9 cm.

3.  Affix a glass siphon tube to a sturdy holder with the end
    of the tube in the middle of the jug and allow to remain
    quiescent for one hour.  After one hour siphon off 250 ml
    being careful not to disturb the material.

4.  Determine suspended solids on the 250 ml portion.  Express
    result as mg/L non-settleable matter.

5.  Calculation:
    mg/L sett, matter = mg/L susp. matter - mg/L non-sett, matter

CHLORINE REQUIREMENT

A rapid method of determining the amount of chlorine which must
be applied to produce a measurable chlorine residual will be used.
Contact time is arbitrarily set at fifteen minutes.   Standardized
dilute sodium hypochlorite (Clorox) is added to the sample in suffic-
ient quantity to produce a measurable residual after the contact
period.  The residual chlorine level is titrated with standard sodium
thiosulfate/starch-iodide, and the chlorine requirement is calculated
as the difference between the amount applied and the residual.

GREASE

Filterable n-hexane soluble substance will be determined by mixing
250 ml of sample and 250 ml of n-hexane in a liter separatory funnel,
filtering the hexane phase through Whatman's #40 and weighing the
residue upon evaporation of the filtrate at 85°C.
                              -53  -

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VJ1
jr
SCREEN NUMBER
101
102
103
104
105
106
107
108
109
111
112
113
114
115
117
118
120
122
INITmL SCREEN LIFE-HRS.
Non -Reparable
Non-Reparable
Non -Reparable
23.5
Non -Reparable
25.25
35.5
Non -Reparable
Nonc-Reparab le
15.5
16.
1.75
28.
15.25
22.
12.5
23.75
26.5
NUMBER OF REPAIRS
--
--
--
7
--
6
6
--
--
2
1
5
1
3
3
5
2
1
ULTIMATE SCREEN LIFE-HRS.
19.
32.25
36.
40.
19.5
95.25
65.5
16.5
18.5
19.5
23.
31.25
30.
30.25
30.75
32.75
44.25
33.5
                                      SCREEN  LIFE  3.1 -  3.8 MGD - HIGH VELOCITY 65 RPM

-------
 J
U1
Ul
SCREEN NUMBER
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
INITIAL SCREEN LIFE-HRS.
49.25
336.75
226.5
228.75
216.
Non-Reparable
32.
118.
299.
216
232.25
283 . 25
288.5
316.75
312.5
293.
283.25
NUMBER OF REPAIRS
3
2
10
5
3
--
7
1
4
4
3
3
2
1
4
4
3
ULTIMATE SCREEN LIFE-HRS.
395.75
516.
428.25
397.25
320.5
239.25
325.75
190.5
364.
324.
355.
306.5
315.25
321.75
385.5
385.25
345.25
                                           SCREEN LIFE  -  2.5-3.6 MGD - LOW VELOCITY 55 RPM

-------
1

5
.Access/on Number
r. Subject Field & Group
0 5 D
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
Organization
     Bureau of Sanitary Engineering,  City of Portland, Oregon
    Title
     DEMONSTRATION OF ROTARY SCREENING FOR COMBINED SEWER OVERFLOWS,
1 Q Authors)
Neketin, Tim H.
Dennis, Harry K. , Jr.
•I z Project Designation
EPA Contract No. 14-12-128 Modification No.
2] Note

7

22 Citation
 23
    Descriptors (Starred First)
     storm runoff, water pollution control
 25
Identifiers (Starred First)
combined  sewage treatment * high-rate screening, solids removal efficiency,
C.O.D.  removal  efficiency
 27
Abstract
The  objective of this demonstration was to determine screen durability,  solids  re-
moval,  COD  removal, and hydraulic efficiency of rotary  fine screening  of storm-
caused  combined sewer overflows.

2300 gpm were evenly distributed to a 60 inch diameter  rotating  (55  rpm)  screen cage
holding 18  ft2 of 165 mesh stainless steel screens  (105 micron opening,  47.1  percent
open area).   During a screening cycle a concentrate sensor stopped the sewage pumps,
ending  the  screening phase and initiating a 30 second cleaning phase during which the
screens were  automatically washed.  At the end of the cleaning phase the pumps  re-
started automatically and a new cycle began.

Performance on storm-caused combined sewage flow averaged 54.8 percent removal  of
settleable  solids,  26.6 percent removal of suspended solids, and 15.5  percent removal
of COD.  Duration of the screening phases averaged  14,6 minutes  with average  hydraulic
efficiencies  dropping from 0.880 to 0.668.

The  ultimate  screen life varied from a minimum of 190.5 hours to a maximum of 516
hours with an average of 346.  Screens required an  average of 3.5 repairs during
this life.  (Schmidt - Portland)
Abstractor
                              Institution
 WR:I02 (REV. JULY 1969)
 WRSIC
                                          SEND TO:  WATER RESOURCES SCIENTIFIC INFORMATION CENTER
                                                  U.S. DEPARTMENT OF THE INTERIOR
                                                  WASHINGTON, D. C. 20240
                                                                               * GPO: 1969-359-339

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Continued from inside front cover....
11022 	 08/67

11023 	 09/67

11020 	 12/67

11023 	05/68

11031 	 08/68
11030 DNS 01/69
11020 DIH 06/69
11020 DBS 06/69
11020 	 06/69
11020 EXV 07/69

11020 DIG 08/69
11023 DPI 08/69
11020 DGZ 10/69
11020 EKO 10/69
11020 	 10/69
11024 FKN 11/69

11020 DWF 12/69
11000 	 01/70

11020 FKI 01/70

11024 DOK 02/70
11023 FDD 03/70

11024 DMS 05/70

11023 EVO 06/70
11024 	 06/70
11034 FKL 07/70
11022 DMU 07/70
11024 EJC 07/70

110 20/	08/70
11022 DMU 08/70

11023 	 08/70
11023 FIX 08/70
11024 EXF 08/70
Phase I - Feasibility of a Periodic Flushing System for
Combined Sewer Cleaning
Demonstrate Feasibility of the Use of Ultrasonic Filtration
in Treating the Overflows from Combined and/or Storm Sewers
Problems of Combined Sewer Facilities and Overflows, 1967
(WP-20-11)
Feasibility of a Stabilization-Retention Basin in Lake Erie
at Cleveland, Ohio
The Beneficial Use of Storm Water
Water Pollution Aspects of Urban Runoff, (WP-20-15)
Improved Sealants for Infiltration Control, (WP-20-18)
Selected Urban Storm Water Runoff Abstracts, (WP-20-21)
Sewer Infiltration Reduction by Zone Pumping, (DAST-9)
Strainer/Filter Treatment of Combined Sewer Overflows,
(WP-20-16)
Polymers for Sewer Flow Control, (WP-20-22)
Rapid-Flow Filter for Sewer Overflows
Design of a Combined Sewer Fluidic Regulator, (DAST-13)
Combined Sewer Separation Using Pressure Sewers, (ORD-4)
Crazed Resin Filtration of Combined Sewer Overflows, (DAST-4)
Stream Pollution and Abatement from Combined Sewer Overflows •
Bucyrus, Ohio, (DAST-32)
Control of Pollution by Underwater Storage
Storm and Combined Sewer Demonstration Projects -
January 1970
Dissolved Air Flotation Treatment of Combined Sewer
Overflows, (WP-20-17)
Proposed Combined Sewer Control by Electrode Potential
Rotary Vibratory Fine Screening of Combined Sewer Overflows,
(DAST-5)
Engineering Investigation of Sewer Overflow Problem -
Roanoke, Virginia
Micros training and Disinfection of Combined Sewer Overflows
Combined Sewer Overflow Abatement Technology
Storm Water Pollution from,Urban Land Activity
Combined Sewer Regulator Overflow Facilities
Selected Urban Storm Water Abstracts, July 1968 -
June 1970
Combined Sewer Overflow Seminar Papers
Combined Sewer Regulation and Management - A Manual of
Practice
Retention Basin Control of Combined Sewer Overflows
Conceptual Engineering Report - Kingman Lake Project
Combined Sewer Overflow Abatement Alternatives -
Washington, D.C.

-------