September 1974
Environmental Protection Technology Series
                                 DEMONSTRATION OF
                           WASTE  FLOW REDUCTION
                                  FROM HOUSEHOLDS
                                   £
                                   55
                                   \
            W
\
 UJ
 CD
                                  National Environmental Research Center
                                    Office of Research and Development
                                   U.S. Environmental Protection Agency
                                            Cincinnati, Ohio 45268

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                                 EPA-670/2-74-071
                                 September 1974
         DEMONSTRATION OF WASTE FLOW
          REDUCTION FROM HOUSEHOLDS
                      by
                Sheldon Cohen
             and Harold Wallman
              General Dynamics
           Electric Boat Division
         Groton, Connecticut  06340
           Contract No. 68-01-0041
            Project No. 11010 GXJ
         Program Element No. 1BB033
               Project Officer

               Harry  E.  Bostian
Advanced Waste Treatment Research Laboratory
   National Environmental Research Center
           Cincinnati, Ohio   45268
   NATIONAL ENVIRONMENTAL RESEARCH CENTER
     OFFICE OF RESEARCH AND DEVELOPMENT
    U.S. ENVIRONMENTAL PROTECTION AGENCY
           CINCINNATI, OHIO  45268

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               REVIEW NOTICE

The National Environmental Research Center,
Cincinnati, has reviewed this report and
approved its publication.  Approval does not
signify that the contents necessarily reflect
the views and policies of the U. S. Environ-
mental Protection Agency, nor does mention of
trade names or commercial products constitute
endorsement or recommendation for use.
                      11

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                            FOREWORD

Man and his environment must be protected from the adverse
effects of pesticides, radiation, noise and other forms of
pollution, and the unwise management of solid waste.
Efforts to protect the environment require a focus that
recognizes the interplay between the components of our
physical environment—air, water, and land.  The National
Environmental Research Centers provide this multidiscipli-
nary focus through programs engaged in:

         o  studies on the effects of environmental
            contaminants on man and the biosphere, and

         o  a search for ways to prevent contamination
            and to recycle valuable resources.

This report covers work on conservation of water in the
home.  Through the use of reduced flow plumbing fixtures
and wastewater recycle systems, it has been demonstrated
that significant reductions in water use and sewage flow
can be achieved.
                               A. W. Breidenbach, Ph.D.
                               Director
                               National Environmental
                               Research Center, Cincinnati
                             iil

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                      CONTENTS
FOREWORD                                         ill

LIST OP FIGURES                                    V

LIST OF TABLES                                    vi

ACKNOWLEDGMENTS                                  vll



   Sections
I        CONCLUSIONS                               1

II       RECOMMENDATIONS                           5

III      INTRODUCTION                              7

IV       NORMAL WATER USE PATTERNS                11

V        BATHROOM FLOW REDUCTION DEVICES:         20
          SELECTION, INSTALLATION AND
          PERFORMANCE

VI       RECYCLE SYSTEMS: DESIGN, DEVELOP-        42
          MENT, INSTALLATION AND PERFORMANCE

VII      HOMEOWNER ACCEPTANCE                     85

VIII     COST ANALYSIS                            89

DC       REFERENCES                               96

X        APPENDIX                                 98

ABSTRACT AND REPORT DATA                          103
                          lv

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                            FIGURES
No.                                                    Page
 1   Schematic Diagram for Homes With Flow               8
      Restricting Shower and Dual Cycle or Shallow
      Trap Toilet
 2   Schematic Diagram for Homes With Flow               9
      Restricting Shower, Dual Cycle or Shallow
      Trap Toilet, and Wash Water Recycle System
 3   Typical Data Collection Form                       13
 4   Shallow Trap Toilet                                21
 5   Econo-Flush Toilet Device                          24
 6   Sink-Bob Toilet Device                             26
 7   Saveit Toilet Device                               27
 8   Econo-Flush Toilet Device: Installed               28
 9   Saveit Toilet Device: Installed                    30
 10  Speakman Auto-flo Shower Head: 13.3,1pm            31
 11  Speakman Auto-flo Shower Head:  9.5 1pm            32
 12  Recycle System With Cartridge Filter               43
 13  Recycle System With Diatomite Filter               44
 14  Recycle System With Cartridge Filter: Installed    47
 15  Recycle System With Diatomite Filter: Installed    48
 16  Polyethylene Storage Tank                          55
 17  Low Level Control System                           56
 18  Low Level Control Float Rod Assembly               57
 19  Typical Data Collection Form - Recycle System      60
 20  Diaclear Diatomite Filter                          61
 21  Diatomite Filtration System: Installed             62
 22  Filter Pressure Drop vs. Time                      65
 23  AMF/Cuno Cartridge Filter                          67
 24  Pram MCM Cartridge Filter                          69
 25  Air Lift Clorox Feeder                             75
 26  Air Lift Feeder Installation                       76
 27  Chlorine Tablet Feeder                             77
 28  Pressurization System

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                             TABLES
No.                                                     Page
 1   Water Savings Summary                                ^
 2   Test Home Characteristics                           12
 3   Distribution of Household Plow Reduction Devices    12
 4   Phase I - Water Consumption Data                    1^
 5   Phase III - Water Consumption Data                  15
 6   Phases I & III - Water Consumption Data             15
 7   Average Household Water Use. Test Data (Phases      16
 ;     I & III)
 '8   Statistical Summary of Normal Water Use Patterns    1?
 9   Hot Water vs. Cold Water Usage for Bath and         19
      Laundry, Ipcd
10   Comparison of Water Closet Plush Volumes            23
11   Test Period Water Consumption Data                  33
12   Statistical Summary of Water Use Patterns During    34
      Test Period (Phase II)
13   Statistical Significance of Individual Water        36
      Savings
14   Water Savings Obtained With Shallow-Trap Toilets    37
15   Water Savings Obtained With Dual Flush Devices      39
16   Water Savings Obtained With Plow Limiting Shower    40
      Heads
17   Shower Hot Water Savings                            41
18   Effect of Lawn Sprinkling on Various Soil Char-     51
      acteristics
19   Wash Water Recycle System: Flow Reduction Summary   52
20   Diatomite Filtration System Performance Data        64
21   Pram MCM Cartridge Filter Performance Data          70
22   AMF/CUNO CG4-DC1 Cartridge Filter Performance Data  72
23   Filter System Performance Summary                   73
24   Clorox Air Lift Feeder Performance Data             79
25   Chlorine Tablet Feeder Performance Data             82
26   Summary of Questionnaire Results                    86
27   Cost Summary - Bathroom Water Saving Devices        90
28   Cost Summary - Wash Water Recycle System            91
29   Cost Comparison                                     93

                               vi

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                       ACKNOWLEDGMENTS
This report was submitted in fulfillment of Project
11010 GXJ and Contract 68-01-0041 by General Dynamics,
Electric Boat Division under the sponsorship of the
Environmental Protection Agency.  The experimental portion
of the project ran from May 1971 to May 1973.

The performance of this project was carried out under the
guidance and supervision of Harold Wallman, Project Manager,
and Sheldon Cohen, Project Engineer.  The valuable assis-
tance of Donald E. Leone, Senior Biologist/Microbiologist
throughout the course of the program is gratefully acknow-
ledged.  The assistance of C. Douglas King, Life Sciences,
Convair Division of the General Dynamics Corporation, in
coordinating activities in the San Diego area is acknow-
ledged with sincere thanks.

Acknowledgment  is made of the cooperation given by the
following volunteer homeowners and their families during
the two-year demonstration program:  Messrs. Andrew J.
Ciminera, George J. Erkan, William J. Fish, Roy F. Holmes,
C. Douglas King, Donald Manley, Paul Murphy, and Gordon W.
Thomson.

The support given the project by Dr. Harry E. Bostian,
Project Officer, Advanced Waste Treatment Laboratory,
Environmental Protection Agency, is acknowledged with
sincere appreciation.
                              vii

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                           SECTION I


                          CONCLUSIONS
WATER SAVING TOILET DEVICES

The results of the program show that water requirements for
toilet flushing can be substantially reduced by commerci-
ally available devices, and in an acceptable manner in terms
of functional, economic, and aesthetic considerations.  All
of the water saving devices tested were convenient to oper-
ate, provided satisfactory operation and performance, and
scored very well in terms of user acceptance.

Water saving (shallow trap) toilets were found capable of
providing reductions in water closet consumption by way of
flush volume reductions afforded with the six units tested.
The average reduction observed (25$) was somewhat less than
anticipated because of the generally lower than average
flush volumes of the original conventional toilets.  Be-
cause of the smaller flush volume utilized by the shallow
trap toilet, proper adjustment of the tank level and fill
rate was found to be important in achieving satisfactory
performance.  The unit costs no more than its standard size
counterpart, and is definitely warranted for new homes or
necessary replacements.  However, because of its relatively
high initial cost, the shallow trap toilet appears to be of
limited economic value for replacement of workable toilets.

Toilet insert devices which converted conventional toilets
to dual cycle operation yielded average reductions in toi-
let flushing requirements of from 18$ (ECono-Plush) to 26#
(Sink-Bob) by achieving respective flush volume reductions
of from 25$ to 50$ for liquid wastes.  The design of the
toilet bowl was found to be important in terms of the ade-
quacy of the reduced flush for liquid and/or solid wastes.
Hence, although the Sink-Bob device has greater water-
saving potential, its effectiveness would be more depen-
dent upon the design of the toilet in which it is installed.

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Installation of the toilet inserts in most standard toilets
can be readily accomplished by the average homeowner.   How-
ever, some of the newer toilet models have a rather elab-
orate flush valve design which would preclude the insertion
and use of the devices tested.  Due to their low initial
cost, as well as their ability to produce significant  re-
ductions in water usage, toilet insert devices possess a
greater potential for cost savings than any of the other
bathroom devices tested.  Increased usage and production of
the toilet devices should result in even lower initial
costs •  additional  innovative  designs,  such  as  the
Saveit toilet insert which was given a preliminary evalua-
tion (when modified for dual flush operation, its flow re-
ducing potential appeared similar to the Econo-Flush),
should promote greater acceptance of these devices by  the
general public.

FLOW LIMITING SHOWER HEADS

The adequacy of a reduced shower flow rate of 13.3 Ipra (3.5
gpm) was clearly established in terms of providing an  ade-
quate water supply and spray pattern.  A further reduction
in flow to 9.5 1pm (2.5 gpm) proved unsatisfactory to  33$
of the participants.

Despite their low cost, the flow limiting shower heads
proved to be of less economic value than anticipated
largely because of the rather limited water savings obtain-
ed with these devices.  This can be traced primarily to the
personal bathing habits (lower than average bathing fre-
quency as compared to previous surveys1 and preference for
tub baths as indicated by personal interviews) of the  pro-
gram participants and does not necessarily invalidate
their potential.  Significant savings in hot water heating
costs, in addition to water savings, should also be achieved
with flow reducing showers where more frequent shower usage
is encountered than in this test program.

WASH WATER REUSE FOR TOILET FLUSHING AND LAWN SPRINKLING

In three of the test homes, the reuse of waste wash water
(bath and laundry) for toilet flushing and lawn sprinkling
was successfully demonstrated throughout the one-year test
period.  The recycle system proved to be manageable and
simple to use, and capable of reliable and safe operation.
No impairment of toilet operation was observed due to the
recycling of filtered, disinfected wash water.  No signif-
icant effects, adverse or beneficial, were noted on lawn
growth or appearance throughout the test period or during
the next growing season.

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In general, the supply of waste bath and laundry water
collected sufficed to meet the demands for toilet flushing.
The supplemental feedwater requirements averaged only 5#
of the total water reused.  A 380 liter (100 gallon) storage
tank should provide an adequate reservoir for an average
size family.  The Incorporation of lawn sprinkling was found
to be useful as a supplemental reuse mode in those homes
with an excess of wash water in order to reduce the waste
overflow to the waste treatment (septic) system.

The performance attained by the diatomite filter system
proved to be satisfactory in terms of aesthetic acceptance
by the homeowner and was achieved with relatively low oper-
ating costs.  Maintenance requirements were found to be
similar to those involved in the operation of a small
swimming pool.  The residual suspended solids in the re-
cycled wash water did produce temporary stains in the
toilet bowls which tended to increase cleaning requirements.
No problems due to foaming were experienced during refill
of the toilet tank.

Continual chlorination of the stored wash water with rela-
tively simple and inexpensive feeders effectively inhibited
bacterial growth, and no unpleasant odors were detected
during normal operation.  Stable chlorine residuals were
maintained at the point of reuse despite the presence of
interfering agents (soaps, detergents), and any potential
health hazard for toilet flushing reuse is considered ex-
tremely remote.  Reuse for lawn sprinkling may present a
possible hazard because of the greater accessibility to the
recycled wash water, should any pathogens be present.  This
potential hazard can be eliminated by suitable underground
discharge, but with substantial increased cost.

A comparison of the relative effectiveness of each of the
four different kinds of units tested, in terms of water
savings, is summarized in Table 1.  As anticipated, the
wash water recycle system produced the greatest savings in
total water consumption.  The overall average water savings
for toilet flushing and/or lawn sprinkling was 305 Ipd,
corresponding to a reduction in total water consumption of
Although the wash water recycle system afforded approxi-
mately three to four times as much water savings as was
provided by either the shallow trap toilet or dual flush
devices  (26# vs. 6.9-8.6$), the projected annual cost for
a mass produced recycle system of $43/yr is about one to
two orders of magnitude greater than the annual cost for
the bathroom flow reduction devices.  A comparison of the

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projected recycle  system cost of $0.39/1000 liters with the
water and sewer use rates in Connecticut indicates that the
system can effect  marginal cost savings for single homes in
high water and  sewer use rate areas, and becomes economi-
cally attractive only when septic systems with poor  drain-
age are encountered.  Cost comparisons with and without
septic systems  and for ranges of water and sewer charges
are shown in Section VIII, Table 29.
                Table 1.  WATER SAVINGS SUMMARY
Unit
tested
No. of
units
tested
Average
no. of
occupants
Water
savings
<$> reduction
in total
water usase
Wash water
recycle system


Shallow trap
water closet


Dual   Sink-Bob
flush
device Econo-
      Plush


Flow limiting
shower head
                11
                           6.3


                           4.5

                           2.8
4.6
44.0


14.8


20.5


12.4



 2.7
                      26.0


                      6.9

                      8.6
1.0
  Ipcd = liters per capita-day


The  reuse  of  waste wash water for toilet flushing and/or
lawn sprinkling can provide tangible benefits  above and
beyond  the savings in water consumption.  The  recycle
system,  by minimizing the surges in outflow  to the septic
system  associated with laundry and bath discharges, as
well as  by reducing total waste flow, allowed  the septic
tank and soil absorption system to operate more effective-
ly.   In two of the three homes, septic system  backup nor-
mally experienced was not observed throughout  the test
period.

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                           SECTION II

                         RECOMMENDATIONS
1.  In order to promote greater public awareness of both
the need for and benefits of water conservation, as well as
the availability of flow reducing devices for both toilets
and showers, broad-based educational/demonstration programs
should be considered in selected areas.  Such large-scale
programs will also generate data with a higher degree of
statistical significance than was possible In this program.
The water saving customer education and appliance test pro-
gram recently completed by the Washington Suburban Sanitary
Commission2*3 is an excellent example of the utilization of
both software (water saving handbooks) and hardware (toilet
inserts, flow limiting shower heads, and inlet pressure re-
ducing valves) in a comprehensive effort aimed at promoting
water conservation by the general public.  More demonstra-
tions can serve to stimulate further development and mass
production of water conservation devices.

In Implementing such broad-based programs, a particularly
fruitful approach might be to induce participation by the
major toilet manufacturers in adaptating one of their
standard models for use as a dual cycle toilet.  The devel-
opment of such toilets would preclude any compatibility
problems which may exist between certain toilet inserts and
some of the current toilet models, provide much greater ex-
posure for this approach to water conservation, and assure
professional installation by an experienced plumber.

2.  The extension of the wash water reuse concept to mul-
tiple family dwellings should be investigated in order to
determine its potential attractiveness for water conserva-
tion and waste flow reduction.  Reuse on a multiple-dwell-
ing basis should be more economical than for a single
dwelling.  Scale-up of the system developed for single
family dwellings should not only permit substantial reduc-
tions in both initial and operating costs, on a per capita
basis, but also allow significant improvements in recycle
system design and performance with minimal impact on total
system costs.  The need for installation of a separate

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distribution system for toilet flushing should not alter the
economics in a decisive manner.  All of the foregoing pre-
sumptions need to be assessed in the light of further de-
tailed design and cost analyses.  In addition, public atti-
tudes toward the reuse of waste wash water on a communal
basis will have to be further explored.  Public safety in
regard to the possible transmission of pathogenic organisms
must also be carefully considered.  It is therefore recom-
mended that a preliminary study phase be conducted, prior to
the design and construction of a prototype unit, in order to
ascertain economic feasibility, public acceptance, and any
potential health hazards.

3.  The results of this project show that reuse of waste
wash water at the single household level for toilet flushing
and lawn sprinkling can be applied successfully.  Also,
the projected economics look marginally favorable for high
user charge areas and where septic systems are flow limited.
Further work on fixing the cost of a mass produced reuse
system for single family dwellings could make the economics
more favorable.  It is therefore recommended that a larger-
scale demonstration program be considered, for single
family dwellings, which would incorporate as an initial
phase the development and detailed costing of a prototype
unit suitable for mass production.  Such a program would
(a) result in a cost and performance optimlz-ed system,
(b) clearly establish the acceptability and safety of this
approach to the homeowner, and (c) could lead to the avail-
ability of a marketable unit.

4.  The previous recommendations regarding home water con-
servation are Justifiable on the basis of cost savings to
the individual homeowner.  On the larger scale of net cost
savings to the community, however, there may be more
effective ways of conserving water and reducing waste flow.
Technological concepts related to wide scale reuse, reduc-
tion of infiltration and integration of utilities could be
more important than home water saving.  User attitudes and
rate structures could also have a determining influence.
It is therefore recommended that a broad study be made of
the technological, economic, public health, aesthetic and
sociological factors relative to water conservation and
waste flow reduction, in order to determine where the most
incentive exists for further research, development and
demonstration.

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                          SECTION III

                          INTRODUCTION

BACKGROUND

The austere reality of a fixed natural fresh water supply
combined with a continuously expanding demand has pro-
moted an increasing awareness of the need for developing
new long-term approaches to water management.  In recent
years, this need has become more acute as the country
becomes increasingly involved with controlling water.
pollution.  According to the Office of Saline Water,^ our
water needs are expected to double by 1980 (from 1.5 to
3 billion cu m/day or 400 to 800 billion gal/day), and by
the year 2000, total water consumption for the United
States may be as much as 4 to 8 billion cu m/day.

In a previous engineering study performed by General
Dynamics for the Federal Water Pollution Control Adminis-
tration,1 it was concluded that reduction of water usage
appeared to be the most practical and economically fea-
sible approach to both water conservation and waste treat-
ment at the household level, and would not become obsolete
as new treatment technology is developed.  The study cited
many household functions in which water is being used
wastefully.  In particular, the study indicated that water
for toilet flushing and bathing could be reduced by approx-
imately 35$ by using presently available devices and
technology.

The practice of water reuse at the household level is
another possible means of reducing both water usage and
waste treatment requirements.  In particular, the use of
waste wash water for toilet flushing (or lawn sprinkling)
appears to be the simplest and most practical method of
conserving water through reuse.  In a city of 100,000
these savings could amount to more than eight thousand
cubic meters of water per day that would not have to be
supplied to the user and eventually treated in the waste
treatment plant.  Besides savings in operating costs for
water supply and waste treatment, the decreased usage would
delay the need for construction of new waste treatment
facilities, for construction of larger sewer lines and

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water mains, and for the development  of new water  sources
which are becoming increasingly scarce and costly.

PROGRAM OBJECTIVES AND SCOPE  OP WORK

The main thrust of this program was to evaluate the rela-
tive merits, water savings, costs, acceptability,  and
potential attractiveness of (a) various presently  avail-
able bathroom flow reduction  devices, and (b) schemes  for
the reuse of household wash water for toilet flushing  and/
or lawn sprinkling.  The flow reduction devices and re-
cycle systems were installed  on a voluntary basis  in a
representative group of eight homes to reduce water con-
sumption in three major water use areas:  (l) toilet
flushing, (2) bathing, and (3) lawn watering.  In  five of
the homes, shallow trap water closets and/or dual-flush
devices were used to reduce the water requirements for
toilet flushing, and flow limiting shower heads were used
to reduce bathing water consumption (see Figure l).  In the
three remaining homes, in addition to the flow reducing de-
vices, an alternate approach  was implemented in which  waste
laundry and bath water were filtered, disinfected, and
pressurized for reuse in toilet flushing and/or lawn water-
ing (see Figure 2).
                              FLOW   I
                              RESTRICTING
                              SHOWER
                              (& BATH)
                                                    , METER)
                                         DUAL CYCLE OR
                                         SHALLOW TRAP
                                         TOILET
                                         LAWN
                                         WATER
 Figure 1.
Schematic diagram for homes with flow restrict-
ing shower and dual cycle or shallow trap toilet
                                8

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      I METER
LAUNDRY
MAQHINE


                                 FLOW
                                 RESTRICTING
                                 SHOWER  I
                                 (BATH)   1
          FV
    r~
 OVERFLOW
                      DISINFECTANT
                      FEEDER
            STORAGE
            TANK
                                                 T
                                                METER]
         METER]
         LAWN
         WATER
                                              DUAL CYCLE OR
                                              SHALLOW
                                              TRAP
                                              TOILET
                                                    PS
                             FILTER
[  PRESSURE  A
I  TANK     I
                                                       NOTE:
                                                       CV = CHECK VALVE
                                                       FV = FEED VALVE
                                                       PS = PRESSURE SWITCH
Figure 2.   Schematic diagram  for homes with flow restrict
             ing shower, dual cycle  or shallow  trap  toilet,
             and wash water recycle  system

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The work performed in this program was accomplished in
three major phases as outlined below:

     1.  Meters were installed in the eight test homes
         to determine normal water use patterns for a
         period of six months.  During this period, the
         design, selection and procurement of all
         necessary devices and systems were accomplished.

     2.  The bathroom flow reduction devices and recycle
         systems were then installed in the eight test
         homes for a period of one year.  Throughout this
         period, both water consumption and performance
         of all devices and systems were continually
         monitored.

     3.  The water saving devices and systems were then
         removed, and the monitoring of normal water usage
         was continued for an additional six months to
         minimize any bias in the results due to seasonal
         changes or long-term variations in family habits.

In addition to the analysis and evaluation of all data
collected during the program, all systems and devices
tested were evaluated in terms of homeowner acceptability
through the use of informal interviews and formal ques-
tionnaries completed by all adult occupants.
                               10

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                         SECTION IV


                   NORMAL WATER USE PATTERNS
HOMEOWNER SELECTION

The homes of eight volunteer families were chosen for the
test program.  To facilitate installation, inspection, and
data collection, six of the homes were chosen in the vicin-
ity of the Electric Boat Division facilities (four in
southeastern Connecticut and two in adjacent Rhode Island).
Two additional homes were chosen in a water-short region
(San Diego, California).  The homes and families were care-
fully chosen to obtain representative conditions of water
use and typical installation costs.  Additional guidelines
for selection of the demonstration homes included homeowner
interest and cooperation, single family dwelling with 3 or
more occupants, accessible plumbing for meter installation,
and drain lines suitably located for installation of re-
cycle systems.

Various relevant characteristics of each of the test homes
and families are shown in Table 2.  The number of occupants
(adults and children) listed in the table reflect condi-
tions at the start of the two-year test program.  Due to
fluctuations in the number of occupants for some of the
families throughout the program, the final average number
may not be the same as that shown in the table.  Toilet
characteristics are also included to serve as a basis for
correlation of the water use data obtained during both
control and test periods.  Table 3 indicates both the num-
ber and specific distribution of each of the household flow
reduction devices and systems installed in each test home.

HOUSEHOLD WATER CONSUMPTION DURING CONTROL PERIODS
(PHASES I AND III)

Throughout most of the two-year test program (May 1971 -
May 1973), water usage was recorded by each of the eight
homeowners, on a weekly basis, on data forms similar to
that shown in Figure 3.  In all eight homes, toilet, bath/

                              11

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shower and  inlet (total) usage were monitored.   In five of  the
homes, laundry usage was also monitored,  and the two homes  in
San Diego  (#1  and #2) recorded lawn water consumption.
               Table 2.  TEST HOME CHARACTERISTICS
Single
family
homes
#1
#2
#3
#4
#5
#6
#7
#8
Service
water
Water pressure
Supply cm He
City
(metered)
City
(metered)
Individ-
ual well
City
(metered)
City
(metered)
City
(metered)
Regional
(metered)
Regional
(non-
metered )
284
320
104-
208
232
475
300
388
284
Waste
disposal
Sewers
Sewers
Septic
tank
Sewers
Sewers
Septic
tank
Septic
tank
Septic
tank
Adults5
1-W
1-NW
1-W
1-NW
1-W
1-NW
2-W
1-W
1-NW
1-W
1-NW
1-W
1-NW
1-W
1-PT
b
Children
1-S
2 -PS

1-S
1-PS
2-S
1-S
7-S
1-PS
3-S-
3-S
Number
of Toilet
baths dssiKn
1 Reverse
trap
^ Siphon
jet
1 Reverse
trap
1 Siphon
Jet
1 Siphon
jet
1 Siphon
Jet
2 Reverse
trap
Wash-
l|r down
Plush
vol.,
liters
17.2
14. 3/
16. 3/
16.7
12.5
16.3-
20.8
14.4
17.9
13. 6/
17.0
15.5/
15.5
   a W=W0rking
    NW=Non-w orking
PT=»Part time
S=School
PS=Pre-school
Table 3.  DISTRIBUTION OF HOUSEHOLD FLOW  REDUCTION DEVICES
Single
family
homes
#1
#2
#3
#4
#5
#6
#7
#8
Shallow
trap
toilets
1
1
1
1
1
1
—
—
Econo-
Plush
__
2
—
—
—
—
2
—
Sink-
Bob
_._
2
—
—
—
—
—
2
Shower
9-^ *w

—
i
i
—
i
—
—
heads
13.3 1pm
1
3
—
—
1
—
2
1
Toilet
. flushing

—
—
—
—
1
1
1
Lawn
snplnklinz
__
—
—
—
—
1
1
__
                                12

-------
                                      HOME NO.
HASE

DATE
TIME
MCCER
READIftflaR
GALLONS '
WATEF
CLOSE
BATH
LAUNDRY
1
T

COLD

HOT

COLD

HOT

INLET


NUMBER OF OCCUPANTS
UNUSUAL
CONDITIONS





































*










































































COMMENTS:
                   Figure 3.  Typical data collection form

-------
The control period, during which normal water  use  patterns
were monitored, was broken down  into  two  six-month periods
(Phases  I and  III) covering  the  beginning and  end  of the
two-year test  program.  Water consumption data for the con-
trol period are summarized in Tables  4, 5, and 6.   Average
values for each household as vjell as  overall averages for
the entire group  are  shown for each function monitored.
The data are'best presented  on a per  capita basis  due to
changes  in the number of occupants in all but  two  of the
test homes.  Atypical data resulting  from leaks, unusual
circumstances, etc.,  were not included in the  data summar-
ies.
         Table  4.   PHASE
I - WATER CONSUMPTION DATA
(5/ri -

Home-
owner
#1
#2
#3
#4
#5
#6
#7
IB
Overall
Average
Ho. or
occu-
pants
5.0
3.0
4.0
3.5
2.7
10.5
5.0
4.5



Inlet
locd
I6la
356a
166
252
260
177
133
200

213

Flush
locd
36.8
105
44.0
67.5
111
42.5
34.4
72.0

64.0

toilet
gihlet
22.8
29.4
26.5
26,7
42.5
24.0
25,9
36.0

29.2


Bath/Shower
Ipcd
11.8
29.9
8.71
20.4
46.3
26.9
is. 5
22.4

22.7
$inlet
7.29
8.40
5.30
8.10
17.8
15.2
11.7
11.2

10.6


Laundrv
Ipcd
79.3
35.6
—
—
—
—
34.0
30.3

44.6
$inlet
49.2
10.0
—
—
—
—
25.7
15.2

25,0
Lawn


water
ID ^ SSlnlet
1340
1000
—
—
—
—
—
--

1170
62
48
-
-
-
-
-
-

55
.4
.4
-
-
-
-
-
-

.4
 •a
  Inlet values shown = Total inlet - lawn water
The per capita water use data show considerable variation
among the eight homes selected.  Some of the more recent
dafa publlshed5*o correlated water consumption with such
parameters as property valuation, education, income, occu-
pation, etc.  In the current program, the relatively small
sample size precludes a meaningful evaluation of such rela-
tionships.  The variability in the data, from one home to
another, is largely a function of the difference in family
habits and "life styles."  Another significant factor
appears to be the type of waste disposal used.  The aver-
age total water consumption for the sewered homes was

-------
        Table  5.   PHASE III - WATER CONSUMPTION DATA
                       (11/72 - 4/73)

Home-
owner
#1
#2
#3
#4
#5
#6
#7
#8
No. of
occu-
pants
8.2
2.0
4.0
4.5
2.3
9.0
5.0
3.6

Inlet
Ipcd
121a
432a
144
193
267
224
153
153

Plush
Ipcd i
31.0
103
36.4
76.6
116
50.9
50.9
66.8

toilet
frLnlet
25.6
23.8
25.3
39.6
43.4
22.7
33.1
43.4


Bath/Shower
Ipcd
17.4
46.2
14.0
13.3
33.7
32.2
35.6
18.9
S&lnlet
14.4
10.7
9.70
6.86
12.6
14.4
23.2
12.3



Laundry
Ipcd
54.4
33.3
—
—
—
37.8
28.8
22.0
JSlnlet
45
7
-
-
-
16
18
14
.0
.7
-
-
-
.9
.8
.3
Overall
Average
210
66.4
32.1
26.4
13.0
35.2
20
.5
Lawn
water
Ipd S&lnlet
53.0
227
—
—
—
—
—
—

140
5.0
20.8
—
—
—
—
—
—

12.9
a
 Inlet values shown = Total Inlet  - lawn water
         Table  6.  PHASES I & III - WATER  CONSUMPTION DATA

Home-
owner
#1
#2
#3
#4
#5
#6
#7
#8
Overall
Average
No. of
occu-
pants
6.3
2.6
4.0
4.0
2.5
10.0
5.0
4.1



Inlet
Ipcd
I45a
384a
157
220
263
190
143
179

210

Plush
Ipcd
34.4
104
41.0
72.5
113
44.8
42.1
69.8

65.2

toilet
fSinlet
23.8
27.1
26.0
32.8
43.0
23.6
29.5
38.9

30.6


Bath/Shower
Ipcd ?
14.0
36.0
10.8
16.6
40.2
28.4
24.9
20.8

23.8
Sinlet
9.68
9.37
6.82
7 -.51
15.2
15.0
17.5
11.6

11.6



L^undrv
Ipcd
69.0
34.8
—
—
—
37.8
31.4
26.5

39.8
S&inlet
47
9



20
22
11

19
.6
.10
—
—
—
.0
.1
.6

.1
Lawn

Water
Ipd"
811
714
—
—
—
—
—
— —

763
5&lnlet
47.0
41.6
—
—
—
—
—
-—

44.3
alnlet values shown = Total Inlet - lawn water
                                   15

-------
253 Ipcd,  as compared with 167 Ipcd for those connected to
septic tanks.  Although two of the eight test homes had
non-metered water supplies prior to the test program, this
was not found to be a meaningful parameter in this study
in terms of correlating total water consumption.

A comparison of the test data with the results of a previ-
ous survey by General Dynamics reported in Reference 1 is
shown in Table 7.  The total (inlet) water consumption of
210 Ipcd is only 13$ less than the published figure and
within the range of values commonly cited in the literature,
The average water closet and bath consumption values, how-
ever, are considerably less than the results of the previ-
ous survey.  Whereas Reference 1 reports toilet and bath
usage as representing 39.2$ and 31.4$, respectively, of
total water usage, the test data for phases I & III show
respective levels of 30.6$ and 11.6$.  On the other hand,
laundry, and kitchen and lavatory usage are significantly
higher than anticipated.  The discrepancies noted probably
reflect the different basis on which the data were collec-
ted.  While the test data were based on suburban/rural
single-family dwellings, the previous survey was probably
more reflective of multiple-family dwellings within an
urban setting.

Table 7.  AVERAGE HOUSEHOLD WATER USE, TEST DATA (PHASES
                            I AND III)
No. of
occu-
pants
Test
data 4.8
Inlet Plush
Ipcd Ip'c'd
a
210 65.1
toilet
%lnlet

30.6
Kitchen &
Bath/Shower Laundry lavatory
ipca 5*»inJ.et Ipcd ^.Inlet Ipcd 5&lnlet

23.8 11.6 39.8 19.1 68.3 29.4
Pre-
vious
survey 4.0   242   95.0 39.2   75.9  31.4  33.1  13.8  37.8  15.7
aOutslde uses included.
 In order to facilitate subsequent statistical evaluation of
 the data in terms of each' of the flow reduction devices
 tested,  an additional tabulation was prepared (Table 8).
 The actual time periods covered in each home for Phases I
 and III  are shown along with the mean per capita usage,
 and the  standard deviations for the entire control period.

                                16

-------
 Table 8.   STATISTICAL SUMMARY OF NORMAL WATER USE  PATTERNS
            (For uses later  modified by water saving devices)
A.   Flush toilet,shallow trap, homes

            .Phase !_	         Phase III          Phases I & III
House-
hold
#1
#2
#3
#4
#5
#6
Time
Period
5A4-12/22
5/12-12/22
4/30-11/T
4/27-10/3
4/26-10/22
5/5-1A3
No. of
days Ipcd
180
214
191
138
165
223
36.8
108
44.0
67.5
111
42.5
B. Sink-Bob homes
Phase I
House-
hold
#2
#8
Time
Period
5 A2 -12/22
4/23-11/12
No. of
days Ipcd
214
202
74.6
72.0
C. Econo-Plush homes
Phase I
House-
hold
#2
#7
Time
Period
5/12-12/22
4/28-10/29
D. Plow limiting
House-
hold
#1
#2
#3
#4
#5
#6
#7
#8
Time
Period
5A4-12/22
__
4/30-11/7
4/27-10/3
4/26-10/22
5/5-1A3
4/28-10/29
4/23-11A2
No. of
days Ipcd
214
184
shower
No. of
days
180
—
191
138
165
223
184
202
74.6
34.4
Time
Period
No. Of No. Of
days Ipcd days locd
12/27-5/2 28
12/27-5/2 126
12/24-4/28 119
11/24-5/6 163
11/22 -5 A 156
2/5-5/2 86
37.1 208
95.5 340
36.4 310
76.5 301
116 321
50.9 309
Phase III
time
Period
sa
36.8 5.3
103 20.8
41.4 6.9
72.0 12.0
113 15.9
45.5 7.2
Phases I &
No. of wo. of
days locd days Ipcd
11/16-4/29 160
214
66.8 362
Phase III
Time
Period
—
11/24-4/29
wo. or
days Ipcd
—
163
-
50
-
.8
74.6
69.5
Phases I
No. of
days
214
347
&
Ipcd
74
42
.6
.1
III
s
14.2
9.2
III
S
14.2
13.1
head homes

locd
11.8
—
8.75
20.4
46.3
26.8
15.5
22.4
Time
Period
12/27-5/2
12/27-5/2
12/24-4/28
11/24-5/6
11/22-5/11
2/5-5/2
11/16-4/29
11 A6 -4/29
No. of
days
28
126
119
163
156
86
163
160


locd
20
46
14
13
33
32
35
18
.0
.3
.0
.3
.7
.2
.6
.9
No. of
days
208
126
310
301
321
309
347
362


Ipcd
14.
46.
11.
16.
40.
28.
25.
20.
6
3
0
2
2
6
4
9

S
5.7
5.1
3.6
4.6
8.0
4.4
6.5
7.6
 S = Standard deviation calculated from monthly averages.
                                  17

-------
The standard  deviations for toilet consumption were com-
puted on the basis of weekly average values.  Bath water
usage exhibited significantly greater irregularities, on a
weekly basis.  In order to obtain a more meaningful statis-
tical analysis, monthly averages for bath usage were used
for computation of the standard deviation in each household.
The per capita usage data were obtained from Tables 4, 5,
and 6, with some modifications required for homes #1 and #2
in order to obtain a meaningful comparison with Phase II
data.

In home #1, the number of occupants changed abruptly from
five to nine early in Phase III.  The change was regarded
as invalidating the family "identity" in terms of water use
habits.  Hence, only the data collected up to the time the
change occurred (180 days + 28 days) were utilized.  In
home #2, a similar modification was made due to a decrease
in the number of occupants from three to two which affected
separately monitored toilets #2 and #3 in which the Sink-
Bob and Econo-Flush devices were installed.  Toilet #1
(shallow-trap toilet), used primarily by the two remaining
occupants, was essentially unaffected by the change.  Also,
a radical change in bathing habits reported by homeowner #2
at the start of Phase II necessitated deletion of Phase I
bath data for comparison purposes.

Significant long-term shifts in water use patterns, from
Phase I through Phase III, are evident from a comparison
of per capita bath water consumption.  For toilet usage,
relatively minor changes were the rule.  In addition, bath
water usage showed greater variability than water closet
consumption based on relative deviations from the mean.

Hot and cold water service to the bath and clothes washing
machine (laundry) was separately monitored and recorded
throughout the test program.  The data are presented in
Table 9 for all three phases of the program, and will serve
as the basis for an analysis of the savings in hot water
usage (and associated fuel costs) effected by the flow lim-
iting shower heads.  Bath and laundry hot/cold water ratios
are also tabulated for each household.  A summary of all
the data indicates that hot water represents 63^ of bathing
water consumption and only 43$ of laundry water usage.
                               18

-------
   Table 9.  HOT WATER VS.  COLD WATER USAGE FOR  BATH AND
                           LAUNDRY,  LPCD
           Phase I	         Phase II               Phase III
House- Bath
hold Hot Cold
#1
#2
#3
#4
8.3
14.6
4.5
10.2
3.4
19.3
3.4
10.2
Laundry
Hot Cold
24.2
9.8
—
—
54.9
25.7
—
—
Bath Laundry
Hot Cold Hot Cold
12.5
13.2
4.9
8.7
3.8 26.5
22.3 9.5
4.2 --
4.18 —
48.1
26.5
—
—
Bath
Hot Cold
15.5
18.2
7.6
8.7
4.5
27.3
6.4
4.6
Laundry
Hot Cold
28.0
11.7
—
—
26.1
21.6
—
— •
 #5  23.1  23.1    —    --   18.2  15.5   ~    —  23.8   9.8   --
 #6  18.6  13.6    —    —   16.7   6.8  27.6  25.4 23.5   8.4  17-4  21.6
 #7   7.6   7.6   19.3  14.8  13.6  12.5  17.8 . 14.4 23.1  14.0  15.9  12.1
 #8  15.2   7.2'   11.7  18.6  18.9   8.3. 14.0  22.8 13.3   5.7   8.3  13.2

Overall
Average
Ratios   1.35        0.69       1.77       0.77       2.03        0.87
                                        19

-------
                        SECTION V

             BATHROOM FLOW REDUCTION DEVICES:
           SELECTION, INSTALLATION AND PERFORMANCE

TOILET FLUSHING REQUIREMENTS

According to toilet consumption data reported  in Reference
1, flushing accounts for a major fraction of the total
household water requirements, ranging from 30$ to 40$.  How-
ever, despite the recent emphasis on water and waste manage-
ment in this country, cleaning action and appearance are
considered at least as important as water consumption.  The
predominant type of flushing action when a tank is used is
the siphon jet type.  When flushing occurs, a  jet of water
is activated under the water level creating a  siphon action
which cleans out the bowl.  The average consumption for
each flushing action is approximately 20 liters (5»3 gal.),
a substantial portion of which is involved in  the bowl clean-
ing function.  Another common toilet design is the reverse
trap type.  The flushing action and general appearance of
the reverse trap bowl is similar to the siphon jet.  The
water surface and size of trapway are smaller, however, and
the depth of seal is less.

Two distinct approaches have been implemented  in this pro-
gram in an attempt to reduce toilet flushing requirements
in a manner consistent with homeowner acceptability.  The
approaches, described below, are:  (a) shallow trap toilets
and (b) dual cycle flush devices.

SHALLOW TRAP TOILET

One of the approaches involved the use of a water saving
toilet designed to use approximately one-third less water
than ordinary toilets.  The specific model selected for
testing was the American Standard Water Saving Elongated
Cadet, shown in Figure 4.  It is similar in appearance
and cost to the standard model except for a noticeably
smaller tank.  Less water is required for flushing due to
the special design of the bowl (shallower trap).  The
Crane Company manufacturers a toilet similar in design
and flush volume called the Radcliffe Water Miser.  This
toilet was not tested due to availability problems rela-
tive to our program schedule.


                                20

-------
Figure 4.  Shallow trap toilet
              21

-------
The original plan called for the incorporation, inside the
toilet tank, of one of the dual flush devices described be-
low.  However, preliminary testing indicated that this was
not possible because (a) the shallow trap toilet would not
operate properly with a reduced flush (less than 11.5 liters),
and (b) the unique design of the toilet flush valve pre-
cluded insertion of either dual flush device.

Shallow trap toilets were installed in six of the eight test
homes, four in southeastern Connecticut and two in San
Diego.  The water saving toilets had the standard 30.4 cm
(12 ) roughing-in dimension and no problems were encountered
by the plumbing contractors in their installation.  In each
case, the float arm had to be bent downwards substantially
in order to keep the water level at the prescribed mark.
The maximum inflow rate to the tank was also adjusted in
order to provide an adequate flush with minimum flush vol-
umes.  The entire installation, including adjustments,
averaged about 30 minutes.

Plush volumes actually used for each of the six shallow
trap toilets are presented in Table 10 and compared with the
flush volumes of the original, conventional toilets.  Init-
ial flush volumes for the water saving toilets ranged from
9.5 to 12.5 liters, representing an average flush volume
reduction of 24$.  Two of the toilets (homes #5 and #6)
required follow-up adjustments due to double flushing prob-
lems noted by the homeowners.  Several field adjustments
had to be made at home #5.  Recurrence of the flushing
problem was finally traced to a defective flush valve
(metering type) which was closing prematurely.  Repair of
the flush valve corrected the flushing problem.  The
double flushing reported in home #6 was found to be related
to the wash water recycle system installed in that home for
toilet flushing.  This was verified by temporarily switch-
ing to the city water supply, during which time the shallow
trap toilet performed satisfactorily.  After switching from
a cartridge to a diatomite filter system, and doubling the
capacity of the pressure tank, the toilet was reconnected
to the recycle system and satisfactory performance was ob-
tained for the remainder of the test period.
DUAL FLUSH TOILET DEVICES

The second approach utilized devices which converted a con-
ventional water closet to dual cycle operation, i.e., a
short flush for liquids and a normal flush for solids.
Three different devices were examined during the program,
                               22

-------
     Table  10.   COMPARISON OP WATER CLOSET PLUSH VOLUMES
Home
1
2
3
4
5
6
7
Number
of
baths
1
3
1
1
1
1
2
Conventional
toilet f lush
vol., liters
17.2
14.8A6.3/
16.7
12.5
16.3/20.8
14.4
17.9
13.6A7.0
Shallow Trap Sink-Bob
toilet flush flush vol.,
vol., liters liters
11.4
12.1
9.5
12.1
12.5-14.4
11.4-12.9
—
Light
8.0/
8.7
—
—
—
—
—
Normal
16.7/
17.0
—
—
—
—
__
EC ono -Flush
flush vol.,
liters
Light
14. V
14.0
—
—
—
—
10. 6/
Normal
17. 1/
17.8
—
—
—
—
14.0/
                                              14.0
17.1
8 3
-4 15.5A5.5
7.6/
8.0
16.7/
15.5
the Econo-Plush, the Sink-Bob, and the Saveit.  Although
similar in effect, all the devices differed substantially
in design, and are described below.  Water consumptions
with the Sink-Bob and Econo-Plush were shown previously in
Table 10.

Econo-Plush

This toilet device consists of two interconnected plastic
tanks open at the bottom which are positioned inside the
toilet tank, and a handleAever assembly incorporating a
unique valve arrangement.  A picture of the assembled de-
vice is shown in Figure 5.  With the exception of some of
the newer toilet models (American Standard, Sears), which
have special flush valves, most standard models with stan-
dard flush valves will accommodate this particular device.
The Econo-Plush operates in the following manner:

     (a) Light flush - This is activated by pushing the
         handle up.  The handle assembly, through a unique
         linkage arrangement, simultaneously opens the
         toilet flush valve and closes a plastic valve which
         seals both plastic tanks from the atmosphere.  The
         contents of both tanks (approximately one gallon)
         are thereby trapped by the vacuum created and a
         reduced flush results.
                               23

-------
Figure 5.  Econo-Flush toilet device

-------
     (b)  Normal flush - This is activated by pushing the
         handle down in the usual manner.  The plastic
         valve now opens in conjunction with the toilet
         flush valve, breaks the vacuum seal and thereby
         allows a full flush to occur.

         A label is included for posting on or near the
         toilet in order to remind the household occupant
         of the new flushing procedure.

Sink-Bob

As shown in Figure 6, this dual flush device consists of a
polystyrene float and lead sinker connected to the float
stem by a split brass ring.  As with the Econo-Plush de-
vice, most standard toilet models will accommodate the
Sink-Bob.  The Sink-Bob attaches to both rod and flapper-
type seals at a point just above the flush valve.  The
device operates in the following manner:

     (a) Light flush - The toilet handle is tripped in the
         normal manner, opening the flush valve and allow-
         ing the water in the closet tank to drain into the
         bowl.  When the level inside the tank has de-
         creased by approximately 50$, the Sink-Bob attains
         sufficient negative buoyancy to prematurely seat
         the flush valve.

     (b) Normal flush - For full flush, the handle must be
         held down during the entire flushing operation to
         prevent premature closing of the flush valve.

Saveit Water Saver

The Saveit water saver, unlike the other devices described
above, will not convert a toilet to dual-cycle operation
without modification.  It does provide a reduced flush of
approximately 50$ in a manner similar to that of the Sink-
Bob.  The device consists of a pre-folded plastic sheet
which is formed around the flush valve and secured with two
anchor rods (see Figure 7).  When flushing occurs, the
flush valve closes prematurely as approximately one-half
of the water in the tank is blocked from gaining access to
the drain.
                                25

-------
               Figure 6.  Sink-Bob toilet device
Home Installation

Dual-flush toilet devices were installed in homes #2,  #7,
and #8.  Pour Econo-Flush units were installed; two in
home #7 for one year, and two in home #2 for a six-month
period.  In home #2, installation was performed by the
homeowner in about 15 to 20 minutes.  A slight increase
in normal flush volumes was observed due to slight adjust-
ments to the float rod necessitated by the presence of the
plastic tank inserts.  In home #7, due to a special toilet
flush valve arrangement, the new trip lever assembly had
to be modified accordingly (see Figure 8).  In addition,
some minor alterations were required in the float rod
orientation.  In both homes, the dual-flush modification
provided a light flush volume nearly 3.8 liters less
than the normal flush volume.
                               26

-------

Figure 7.  Saveit toilet device
             27

-------
ro
oo

                      Figure 8.  Econo-Flush toilet device:  installed

-------
In order to correct occasional binding of the handle which
occurred after light flush tripping of one of the toilets
in home #7, the handle assembly was removed and lubricated
with Teflon spray.  Subsequent flushing problems in home #7
were related to intermittent clogging of the inlet valves
with recycled water solids, and traced to the flow restric-
tive design of the downcomer tube.  Replacement of both in-
let valves with valves of newer, more modern design cor-
rected the problem.

Pour Sink-Bob units were installed, two in home #8 for one
year, and two in home #2 for a six-month period.  Installa-
tions of all units were accomplished by the homeowners in
approximately 3 to 5 minutes, without any modifications
required.  In home #2 the Sink-Bobs were attached to rod-
type flush valvesj in home #8 the devices were attached to
flapper valves.  In the light flush mode, flush volumes
were reduced by about 50$•

The Saveit toilet device was installed in two homes not
connected with the test program for a preliminary qualita-
tive evaluation.  The installation was readily performed by
the homeowner in about 5 minutes.  As noted above, the
Saveit device is not a dual-flush device, and provides a
reduced flush only.  In one of the toilets, the device did
not provide an adequate flush for solids.  The Saveit was
subsequently modified for dual flush operation by removing
a small semi-circular section at the base of the unit, and
operated satisfactorily thereafter.  The light flush was
achieved by depressing and releasing the toilet handle in
the normal manner.  For a full flush it was necessary to
keep the handle down until the toilet tank had been com-
pletely emptied.  For the last two months Of Phase II, the
modified Saveit was installed in home #7 (see Figure 9)
for a limited qualitative comparison with the Econo-Flush
device.  The modified device provided a flush reduction of
about 4.8 liters (similar to the Econo-Flush).  Because of
the limited use of the Saveit, results with this device are
not Included in the summary tables elsewhere in this report.

FLOW LIMITING SHOWER HEADS

Published surveys of water usage (references 1 and 5) indi-
cate that approximately 30$ of the total household water
consumption is used for bathing.  It is interesting to note
the disparity between this value and the overall average
usage recorded during Phases I and III of approximately
12$.  This points to the possibility that the group of
eight families selected are atypical with respect to bath-
ing patterns (lower than average bathing frequency).  They


                                29

-------
u>
o
                                                                                   :. -
                         Figure 9.  Saveit toilet device:  installed

-------
also seemed to have a greater preference for tub baths than
showers.

Shower heads with built-in flow limiting orifices are avail-
able which can reduce water consumption rates from the
typical 19 to 38 1pm (5 to 10 gpm) to 9.5 or 13.3 1pm (2.5
to 3.5 gpm).  The actual amount of water saved will depend
primarily on the system water pressure and the personal
habits of the bather.  Two different Speakman flow limiting
shower heads were selected for testing.  The first of these,
shown in Figure 10, is equipped with a 13.3 1pm integral
"Auto-flo" flow limiting orifice.   This shower head has a
fully^adjustable spray, integral ball Joint and a 5 cm face.
The second shower head, shown in Figure 11, is equipped with
a 9.5 1pm integral "Auto-flo" limiting orifice.  It is also
of the adjustable spray, ball Joint type but has a much
narrower shape.  Both shower heads have standard 1.27 cm
(l/2M) I.P.S. female inlets which are compatible with stan-
dard shower arms.  A total of eleven flow limiting shower
heads were installed in the eight test homes, with the
specific distribution shown previously in Table 2.  Install-
ation can be performed by a homeowner in about 5 minutes.

     Figure 10.  Speakman Auto-flo shower head:  13.3 1pm
                                31

-------
                                      i':";  m*
    Figure 11.  Speakman Auto-flow shower head:  9.5 1pm
WATER METERS

Pre-calibrated, domestic-type water meters were used for
monitoring total water consumption as well as water used
for toilet flushing, bathing, laundering and lawn sprink-
ling as indicated before in Figures 1 and 2.  Neptune Tri-
Seal split-case meters, 1.59 cm (5/8") size, were selected
for all cold water lines, and Neptune Trident Type S
meters were used for all hot water lines (bath and laundry).
Both- meters provide very close to 100$ accuracy from 0.9^
1pm to 75 Ipro and beyond, and produce a negligible pres-
sure drop over the range of Interest for all fixtures mon-
itored.  The meter registers were calibrated in gallons,
and could be read to the nearest tenth of a gallon.

TEST PERIOD WATER CONSUMPTION DATA

Daily average water use values are presented in Table 11 on
a per capita basis for all eight test homes.  The data

-------
cover roughly a one-year period froip November 1971 to
November 1972.  In Table 12, the  data  have been recast in
a more convenient form for evaluation  of water savings and
statistical analyses.  The actual time periods covered are
shown along with the mean per  capita usage and correspond-
ing standard deviations.  As noted in  Section IV,  the
standard deviation for water closet consumption and bath
usage were computed on the basis  of weekly averages and
monthly averages, respectively.
  Table 11.  TEST PERIOD WATER CONSUMPTION DATA  (PHASE  II)
Hdtne-
owner
1
2
3
4
5
6
7
8
No. of
occu-
pants
5.2
2.5
4.1
3.4
2.4
9.9
5.0
4.1
Overall
Average
Inlet
Ipcd
136a
300a
149
172
260
195
99.8
117
178
Flush toilet
Ipcd
20.4
82.3
35.6
50.0
103
27.6
39.4
47.5
52.0
S&inlet
15.0
27.4
23.9
29.1
43.2
14.2
39.5
40.5
29.1
Bath/Shower
Ipcd J&lnlet
16.1
35.9
9.1
14.4
32.2
23.8
25.8
27.6
23.1
11.8
12.0
6.1
8.4
12.4
12.3
25.9
23.7
14.1
Laundry
Ipcd
74.8
36.0
—
—
—
53.0
32.2
36.8
46.6
JSlnlet
54.7
12.0

—
—
27.2
32.3
31.5
31.5
Lawn t{
Ipcd
1520
497
—
—
—
—
—
—
1010
later
J&lnlet
68.0
39.8
—
—
—
—
—
—
53.9
a
 Inlet values shown » Total inlet - lawn water.
In home #2, Econo-Flush dual-flush devices were tested for
a period of eight months in water closet #2 and #3.  The
Econo-Flush devices were then replaced by two Sink-Bobs for
a comparative evaluation.  However, as indicated in Table 12,
only 31 days of testing were completed.  This was because
the primary user of water closet #2 and #3 vacated the home
for the remainder of Phase II.

-------
B.
C.
D.
       Table 12.  STATISTICAL SUMMARY OP WATER USE
          PATTERNS DURING TEST  PERIOD (PHASE II)

Household

Time period
No. of
days
Shallow Trap Toilet
1
2
3
4
5
6
Sink -Bob
2
8
1/5 - 12/20
1/6 - 12/27
11/13 - 11/25
10/29 - 10/27
11/7 - 11/19
1A3 - 12/4

9/27 - 11/1
10/4 - 11/12
328
309
378
356
342
290

31
363

Ipcd

20.6
76.3
35.6
50.0
113
27.6

55.8
47.4
Q
sa

3.1^
10.1
4.55
7.97
17-4
6.07

12.0
8.8
EC ono -Plush
2
7
1/6 - 9A3
10/29 - 11/22
215
387
49.8
39.4
13.2
6.1
Plow Limiting Shower Heads
1
2
3
4
5
6
7
8
1/5 - 12/20
1/6 - 12/27
11/13 - 11/25
10/29 - 10/27
11/7 - 11/19
1/13 - 12/4
10/29 - 11/22
10/4 - 11/12
328
309
378
356
342
321
387
363
16.1
35.8
10.1
14.6
32.2
23.8
25.8
27.6
3.0
6.1
2.0
3.1
6.9
3.7
5.9
10.3
 aS = Standard deviation

-------
Statistical Analysis

Prior to a comparison of test and control period data, a
statistical analysis was performed to determine whether or
not the differences between the mean values being compared
(water savings) were statistically significant.  For this
analysis, the student's_t-distribution was used to test the
null hypothesis:  X., - X2 = 0.  The t-distribution is a
measure of the deviation between the means of two random
groups of data.  The specific values of t were calculated
from the following equation':


         t =    Xl - X2
(n,
                S
nl +n2
                 1

     where:

         X, = mean usage, control period

         &2 = mean usage, test period

         S, = standard deviation, control period

         S2 = standard deviation, test period

         n- = number of data points, control period

         n2 = number of data points, test period

The calculated values of t were compared with the theoreti-
cal values of t at P = 0.05 (95$ confidence level) in Table
13 at the corresponding number of degrees of freedom
(n, + ru - l).  The decision to reject the null hypothesis
(equivalent to a confirmation of statistical significance
at the 95$ confidence level) was made when the calculated
value of t was found to be greater than the theoretical
value.

For the shallow trap toilets, the null hypothesis was re-
jected in five of the six homes.  In home #5* the means
were statistically indistinguishable as the average values
were, in fact, identical.  As for the dual-flush devices,
both sets of data for the Sink-Bobs received statistical
confirmation, while only one set of Econo-Flush data was
found to be statistically significant.  In the other set
(home #7) the control period standard deviation is seen to
be excessively large relative to the rather small differ-
ence in means observed.


                                35

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                      Table  13.  STATISTICAL SIGNIFICANCE OF INDIVIDUAL WATER SAVINGS




»
•P .p

H £
J ^
CO
1
3 "o
to ,0
§•§
o c
O J-
W *•


g «
Ital W
•H 'C
•P (G
a x
H h
8 i
l-l X
Control period data
(Phases I & III)
House-
hold
1
2
3
4
5
6

2
8
2
7
1
2
3
4
5
6
7
8
Xl»
Ipcd
36.8
L03
41.4
72.0
L13
45.5

74.6
69.5
74.6
42.1
14.6
46.3
11.0
16.2
40.2
28.6
25.4
20.9
Standard
deviation
5.3
20.8
6.9
12.0
15.9
7.2

14.2
9.2
14.2
13.1
5.7
5.1
3.6
4.6
8.0
4.4
6.5
7.6

Nl
31
45
41
30
39
35

27
37
27
37
9
6
12
11
12
12
12
12
Test period data
(Phase H)
V
Ipcd
20.6
76.3
35.6
50.0
113
27.6

55.8
47.4
49.8
39.4
16.1
35.8
10.1
14.6
32.2
23.8
25.8
27.6
Standard
deviation
3.1
10.1
4.5
7.9
17.4
6.0

12.0
8.8
13.2
6.1
3.0
6.1
2.0
3.1
6.9
3.7
5.9
10.3

N2
47
44
25
40
48
36

4
28
13
26
12
12
12
12
12
11
12
12

Student's t - test

t _
calc.
16.7
7.5
3.7
9-1
0.0
11.2

2.43
9.6
5.1
0.96
0.74
3.4
0.73
0.94
2.51
2.69
0.15
1.74
t at
P - 0.05
1.99
1.98
2.00
1.99
1.99
1.99

2.04
2.00
2.02
2.00
2.12
2.46
2.39
2.40
2.39
2.40
2.39
2.39
w tf *tir f\
H * 9S X mm X C3 1}
V 12
Reject
Reject
Reject
Reject
Accept
Reject

Reject
Reject
Reject
Accept
Accept
Reject
Accept
Accept
Reject
Reject
Accept
Accept
GO
ON
           NOTE:   The decision to reject is equivalent to a confirmation of
                  statistical significance.

-------
In only three of the eight homes using flow limiting
shower heads (#2, #5, and #6) were the data found to be
statistically significant.  In those cases for which the
null hypothesis was accepted, any observed differences in
average water use (positive or negative) will be set equal
to zero.

WATER SAVINGS

Bathroom Plow Reduction Devices

Conventional toilets were replaced by shallow trap toilets
in six of the eight test homes.  The water saving toilets
were advertised as consuming approximately one-third less
water for flushing then conventional toilets.  Actual
measured flush volume reductions (as shown previously in
Table 10) averaged 25$, ranging from 1% to 35$.

Table 14 shows the actual water savings in each of the six
homes.  In general, the percentage reduction in water usage
correlated fairly well with the measured flush volume re-
ductions, ranging from 0$ to 44$, with an average reduction
of 25.6$.  This indicates that the toilets operated depend-
 ably.   Water savings ranged from 0 to 26.7 Ipcd, with an
average savings of 14.8 Ipcd.  The percentage reduction in
total water usage averaged 6.9$, with the maximum value
of 11.2$ attained in home #1.
 Table 14.
WATER SAVINGS OBTAINED WITH SHALLOW TRAP FLUSH
                  TOILET
Conventional
toilet
House-
hold
1
2
3
4
5
6


No. of
occupants
5.1
2.0
4.0
4.0
2.5
10.1



locd
36.8
103
41.4
72.0
113
45.5


Shallow trap
toilet
No. of
occupants
5.2
2.0
4.1
3.4
2.4
9.9
Average
savings

Ipcd
20.6
76.3
35.6
50.0
113
27.6


Water
savings

Ipcd
16.2
26.7
5.8
22.0
0
17.9

14.8
$
reduction
44.0
26.1
14.0
30.6
0
38.8

25.6
% reduction
in total
water
usage
11.2
7.0
3.7
10.0
0
9.4

6.9
                                 37

-------
In three of the test homes, six toilets were modified for
dual cycle operation by either the Sink-Bob or Econo-Plush
toilet inserts.  The Sink-Bob and Econo-Plush devices pro-
vide respective reductions of approximately 50$ and 25$
respectively when operated in the light flush mode.  The
overall reduction in« water consumption will depend on how
often the light flush is used as well as the adequacy of
bowl cleaning by the light flush.

Table 15 presents the water savings actually obtained over
the one-year test period.  The Sink-Bob devices performed
well in both homes #2 and #8, resulting in an average water
savings of 20.5 Ipcd, equivalent to an average reduction in
toilet flushing of 28.6$.  The Econo-Plush device gave
better 'than anticipated results in home #2, but proved in-
effective in home #7.  The insignificant water savings in
the latter home was partially attributable to a relaxation
of toilet flushing habits (failure to use the reduced flush)
due to the recycle system installation and the resulting
abundance of wash water for toilet flushing.  Another sig-
nificant factor was the relative infrequency of light flush
usage by the three children.  Average savings for the Econo-
Plush was 12.4 Ipcd (l6.6$).  The overall average water
savings for both dual flush devices was 16.5 Iped (22.6$).
The percentage reduction in total water usage averaged 6.0$.

Eleven flow limiting shower heads were installed in the
eight test homes.  As noted earlier, two different types
were employed.  In five of the homes, 13.3 1pm flow limit-
ing shower heads were used, and 9.5 1pm shower heads were
used in the remaining three.  The water savings produced by
these devices are shown in Table 16.  As indicated in Table
13, in only three of the homes (#2, #5, and #6) were the
data found to be statistically significant.  In the re-
maining five homes, the mean usage values (test vs. control)
were found to be statistically indistinguishable.  In general,
the observed lack of effectiveness appears to be primarily
a function of personal bathing habits.  In four of the
homes (#1, #3, #4, and #7), significant shifts in bathing
frequency and/or habits from Phase I to Phase III were ob-
served (see Table 8).  In homes #3 and #4, showering
accounted for only a minor fraction of all bathing activ-
ity.  An overall average water savings of only 2.7 Ipcd,
corresponding to a percentage reduction of 7.1$ was ob-
served.  The percentage reduction in total water usage
was only l.<
                               38

-------
                             Table 15.   WATER SAVINGS OBTAINED WITH DUAL FLUSH DEVICES
House-
hold
2
7a
8
Convent:
Toll
No. of
occu-
pants
1.5
5.0
U.I
ional
,et
Ipcd
7k.6
1*2.1
69.5
Dual flush devices
Sink bob
No. of
occu-
pants
1.5
.—
k.l
Ipcd
55.8

kj.k
Econo-flush
No. of
occu-
pants Ipcd
1.5 ^9.8
5.0 39-U
— —
Average
savings
Water Sav:
Sink-bob
Ipcd
18.8
...
22.1
20.5
%
Reduc.
ofFlusl
25.2
...
32.0
28.6
t
Reduc.
i of total
U.9
...
12.3
8.6
.ngs
Econo-flush
Ipcd
2k. 8
2.7*
...
12.U
*
Reduc.
ofFlus!
33.2
6.Ua
...
16.6
Reduc
L Of tot
6.5
1.9a
—
3.3







U)

Overall average
savings
Iped
16.5
% Reduction % Reduction
of Flush of total
22.6
6.0
        Water savings set = 0 based on statistical analyses

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                         Table  16. WATER SAVINGS OBTAINED WITH FLOW LIMITING SHOWER HEADS
House-
hold
Ia
2
3a
k&
5
6
7*
8
Conventional
shower
heads
No. of
occu-
pants
5.1
2.7
^.0
k.O
2.5
10.1
5.0
k*l
Ipcd
lk.6
1*6.3
11.0
16.2
kO.2
28.6
25A
20.9
Flow limiting
shower heads
13.3 1pm
No. of
occu-
pants
5.2
2.5
—
—
Z.k
— .
5.0
*.l
Ipcd
16.1
35.8
—
—
32.2
—
25.8
27.6
9.5 1
No. of
occu-
pants
—
—
*.l
3.^
—
9.9
...
—
tan
Ipcd

mum^m
10.1
1^.6
—
23.8
— _
—
Average
savings

Overall avg.
savings
Water savings
13.3 1pm
Ipcd
-1.5
10.5

—
8.0
—
-o.U
-6.8
3.7
% Redu.
of
bathing
-10.3
22.7
—
—
19.9

-1.6
-32.5
8.5
Ipcd
2.7
% Red.
of
total
-1.0
2.8
—
—
3.1
—
-0.3
-3.8
1.2
9.5 Ipa
Ipcd
	
...
0.9
1.6
—
l* .8
—
—
1.6
$ Redu.
of bathing
7.1
% Redu.
of
bathing
	

8.2
9.9
•»*»•«
16.8
—
—
5.6
% Red.
of
total
—

0.6
0.7
—
2.5
—
	
0.8
% Redu.
of total
1.0
s
      water  savings considered  statistically insignificant  (set = 0) for calc.   of average  savings,

-------
Shower hot water savings, presented in Table 17, ranged
from 0'to 5.2 Ipcd (0 to 21.8$ reduction), with an average
savings of 1.5 Ipcd (7.2$ reduction in shower hot water
usage).  Evaluation of the shower hot water savings was
based on the same statistical considerations as were applied
to the data in Table 16.

              Table 17.   SHOWER HOT WATER SAVINGS
House- Phases I & III
hold Ipcd
la
2
3a
4a
5
6
7a
8a
12.2
16.1
5.7
9.4
23.4
20.2
14.9
14.4
Phase II
Ipcd
12.5
13.2
4.9
8.7
18.2
16.7
13.6
18.9
Hot water savings
Ipcd
-0.3
2.9
0.8
0.7
5.2
3.5
1.3
-4.5
% reduction
-2.5
18.0
14.0
7.5
21.8
17.3
8.7
-31.0
                          Average
                          savines
7.2
 aHot water savings in  these homes set equal to zero
  based on results of statistical analysis summarized
  in Table 12.

-------
                        SECTION VI

           RECYCLE SYSTEMS:  DESIGN, DEVELOPMENT
               INSTALLATION AND PERFORMANCE
OVERALL SYSTEM DESIGN, INSTALLATION AND PERFORMANCE

Treatment, Storage and Toilet Flushing Reuse

Since toilet flushing normally accounts for the major
fraction (30-40$) of household water usage, the reuse of
waste wash waters (bath and laundry) for this function is
a potentially attractive scheme.  The actual amount of
water saved will depend upon the nature of the balance
between waste wash water generated and toilet usage in a
particular household.  If necessary, a more favorable bal-
ance can be effected by (a) a reduction in toilet flushing
requirements through installation of a suitable dual-flush
device, or (b) an increase in the"available supply by in-
clusion of lavoratory waste water.

Apart from the necessity of providing an adequate water
supply at all times, other desirable system criteria in-
clude minimum odor, minimum staining properties, accept-
able clarity and color, and prevention of health hazards.
It is, of course, also necessary to achieve these criteria
under the practical constraints of acceptable costs, main-
tenance, and space requirements.  One of the aims of this
program was to develop sufficient information with which
to establish an acceptable compromise in terms of perfor-
mance, cost, and safety.

All of the functions and components involved in the house-
hold wash water recycle systems are illustrated in Figures
12 and 13.  These configurations are the ones chosen for
extended testing after optimization of component choice and
arrangement.  The prior development work and individual
component performance are described in more detail in later
subsections of this chapter.  Both systems finally chosen
are fundamentally similar with the exception of the spec-
ific design of the filtration and disinfection systems.
The recycle system incorporating the diatomite filter


                               42

-------
LAUNDRY
DOLE
SOLENOID
VALVE
                                                                      TO FLUSH
                                                                      TOILET A


                                                                        1/2"
                                                                      COPPER!
                                           POLYETHYLENE
                                           STORAGE TANK
                                         1/3 HP
                                         SHALLOW WELL
                                         JET PUMP
                           CLOROX
                           FEEDER ASSY
                                             CARTRIDGE
                                             FILTER
      Figure  12.   Recycle system with cartridge  filter

-------
                                      BATH
  1" FLEXIBLE
  HOSE
LAUNDRY
                                             1-1/2" COPPER
                                             OR PVDC
                                                                   1/2"

                                                                   TO TABLET FEEDER
                                         POLYETHYLENE
                                         STORAGE TANK
                                         1/3 HP
                                         SHALLOW WELL
                                         JET PUMP
                                           1-1/4" BYPASS
                                               1"CHECK
                                               VALVE '
                                                                      DIATOMITE
                                                                      FILTER
                                    1"CHECK
               115V Zir    \            VALVE
                     1/30HPRECIRC.
                     PUMP
                                                               PVC
                                                      //      BACKWASH
                                                      '        VALVE
                                                           DF = DISINFECTANT FEEDER
       Figure  13.   Recycle  system with diatomite filter

-------
(shown in Figure 13) was somewhat more complicated because
of the need for recirculation as explained below.  Laundry
and bath water were collected in a suitably sized vented
storage tank, provided with an overflow pipe, side bottom
outlet, and a low-level control system for supplemental
feed water.  The stored wash water was either continuously
(see Figure 12) or intermittently (when the pressurization
pump operated, see Figure 13) disinfected prior to filtra-
tion.  The treated water was pressurized by a 1/3 HP
shallow well jet pump mounted on either a % or 115 liter
pressure tank, controlled by a pressure switch over the
range of 105 to 210 cm Hg.  When the pump was activated,
wash water was pulled through a cartridge or dlatomite
filter and pressurized.  This arrangement, with the filter
upstream of the pump, had several advantages:
   i
     (l) The filtration system operated under a vacuum
         (0-65 cm Hg) while the pump was running, and only
         4.5 to 11.5 cm Hg positive pressure at all other
         times.  Hence, the system, up to the pump check
         valve, was under minimal pressure at all times,
         thereby minimizing leaks as well as filtration
         system design requirements.

     (2) The pump was protected by the filter from any
         harmful debris.

A filter by-pass with an in-line strainer was also pro-
vided in case of filter breakdown.

In order to preclude contamination of an existing water
supply, no cross-connections were allowed, and a suitable
air gap was provided for the feed water inlet to the
storage tank.  For additional protection of the potable
water system, an A.S.S.E. (American Society of Sanitary
Engineers) approved double-check valve assembly (Watts
No. 9 backflow preventer) was installed in the house
service line.  This device provides positive protection
against back-syphonage and backflow if the supply pressure
should ever fall below recycle system pressure at the same
time that a cross-connection (pressure or gravity type)
existed.  Some localities may require the installation of
a more sophisticated backflow prevention device such as a
reduced pressure device (similar to the double-check valve
assembly with an added differential pressure controlled
relief valve).  An additional requirement of the national
plumbing code, not imposed on any of the test units in-
stalled, states that all non-potable water supplies must
be color coded yellow.  In general, plastic piping,
fittings and valves were used for those lines not under a

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positive pressure greater than 35 cm Hg.  All other lines
consisted of copper tubing and bronze fittings.  The
acceptance of plastic piping for uses other than cold water
drain lines, varies from one locality to another, and
appears to be gaining in favor in many areas.  The design
and installation of all recycle systems were subject to
prior approval by local and state authorities in both
Connecticut and Rhode Island.

Two local plumbing contractors were used to install the
wash water recycle systems in the three test homes.  The
systems in homes #7 and #8 were installed by the same con-
tractor   (see Figures l4 and 15).  The installations in
homes #7 and #8 were completed in approximately 8 hours
each.  In home #7, about one-half of the time was spent
plumbing the recycle system (cartridge filter), per se,
with the remaining time (4 hours) spent on connection of
the system to the house plumbing.  In home #8, 5 hours was
spent on recycle system (diatomite filter) interconnec-
tions, with only 3 hours required for house plumbing con-
nections.  In home #6, approximately 10 hours were required
for system interconnection.  This excessive installation
time reflects the plumber's lack of experience with FVC
piping and fittings.  Pour hours were spent on house plumb-
ing connections.

In general, no impairment of flush toilet operation was
observed in the three test homes due to the recycling of
filtered, disinfected wash water.  In two of the three
homes, reduced flush operation was successfully employed.
Continual chlorination of the stored wash water effectively
inhibited bacterial growth, and no unpleasant odors were
detected in any of the bathrooms during normal operation.

Stable chlorine residuals were maintained at the point of
reuse, despite the presence of interfering agents (soaps,
detergents).  In general, the susceptibility of the more
resistant enteric bacterial pathogens to free chlorineois
essentially the same as that of the coliform bacteria,"
which were readily controlled.  Viruses are more resistant
to chlorine than coliform bacteria, and a negative coliform
test does not necessarily exclude viruses.  However, with-
in a home, the possibility of viruses (or other pathogenic
organisms) being transmitted by toilet flushing reuse,
although possible, is less likely than by normal means
(physical contact, inhalation, or ingestion).

The clarity and color of the recycled water attained by the
diatomite (swimming pool) filter proved to be satisfactory
in terms of aesthetic acceptance by the homeowner and was


                              46

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Figure 14.
Recycle system with cartridge filter:
               installed

                  47

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Figure 15.
Recycle system with diatomite filter!
              installed

                 48

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achieved with relatively low operating costs and maintenance
requirements.  The residual suspended solids in the recycled
wash water did produce temporary stains in the toilet bowls
which resulted in increased cleaning requirements.  Since
dissolved soaps and detergents were not removed by the dia-
tomaceous earth, the foaming tendency of the wash water was
not significantly reduced.  However, no problems due to
foaming were observed at the toilet inlet valve during re-
fill of the water closet tank.

Lawn Watering Reuse

The original program plan called for the installation of
two wash water recycle systems in San Diego, California,
similar to those described above, to explore the feasibil-
ity of reducing lawn water consumption in a water short
region.  The normal water use patterns summarized previously
show that lavin water consumption averaged 1340 and 1000 Ipd
respectively in homes #1 and #2 during the growing season.
Based on full utilization of laundry and bath wastes, lawn
usage could have been reduced by 455 Ipd (34$) and 197 Ipd
(20$), respectively.  Maximum utilization would probably
have required a significant change in lawn watering habits
by both homeowners in order to use the treated water as it
became available.

Because of possible harmful effects of waste wash waters on
the lawns, the reuse of laundry water was pre-tested during
the preliminary monitoring period (Phase I).  The principal
concerns are with chemical effects on vegetation and soil
chemical makeup.  In general, soils that are acid, sandy
and well-drained should provide the most favorable results.
Homeowners #1 and #2^ watered a small test plot with laun-
dry water on a weekly basis and no short-term (3-4 months)
adverse effects were noted.

Just prior to the scheduled installation, however, the San
Diego Public Health Department failed to approve the ex-
perimental reuse of waste water on lawns.  They were
opposed, in principle, to any decentralized control of
waste water management, and did not wish to encourage
such a trend by setting a precedent in this case.

In order to accomplish the original program objectives,
the reuse of wash water for lawn irrigation was subse-
quently incorporated into two of the toilet flushing recycle
systems in the Southeastern Connecticut area (homes #6 and
#7) primarily to supplement existing toilet flushing reuse
and further reduce waste flow.  This was done with the
full cooperation of local public health officials even
after being appraised of San Diego's objections.

                              49

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In home #6, a 33 sq m test plot received average waterings
of 100 Ipd for three months and 400 Ipd for another three-
month period.  In home #7, a 14 sq m test plot was watered
an average of only 15 Ipd.  Revolving sprinklers were
operated by shut-off valves located near the pressure
tank outlet, for convenience as well as safety.  No oper-
ational problems, such as clogging of the orifices, were
encountered during the test period.  The soil at both
locations was tested and characterized as generally sandy
and acidic.  At home #6, where much larger amounts of
wash water were reused for lawn sprinkling, the soil
drainage was characterized as fair.  The drainage at home
#7 was generally poor.  No significant effects, adverse
or beneficial, were noted on lawn growth or appearance
throughout the test period or during the next growing
season.  The sprinkled areas were not sheltered from the
normal rainfall and were, in fact, exposed to record
rainfalls throughout portions of the test period.  Prob-
lems may have developed If drought conditions prevailed.
It is unfortunate that the lawn sprinkling tests could not
have been conducted in San Diego to obtain more conclusive
information.

The effect of lawn sprinkling with filtered, disinfected
wash water on various soil characteristics is shown in
Table 18.  The soil analyses were performed on samples
taken at the end of the test period.  Soil samples taken
from the non-sprinkled area were assumed to be representa-
tive of soil conditions prior to the period of reuse.
Although detergents are formulated of sodium salts of weak
acids, the pH of the sprinkled wash water was found to be
essentially neutral.

Excessive amounts of phosphate may tie-up iron, magnesium,
calcium and other essential metals needed for plant growth.
In both homes, low-phosphate detergents were used.  The soil
analyses indicate no significant decrease in the avail-
ability  of the essential metals listed in Table 18.  Spray-
ing the lawns with wash water apparently effected small re-
ductions in soil moisture content of from 10 to 20$.  The
moisture reductions may reflect an increased water repell-
ancy, or may result from the normal differences in soil
characteristics at the locations sampled.  The effect of
sodium buildup on soil permeability may become significant
on a long-term basis.  However, the lawn sprinkling tests
were conducted on such a limited basis that sodium levels
were not evaluated.  Additional long-term testing of the
lawn watering scheme would be required for a definitive
evaluation of its effect on soil moisture.
                              50

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   Table 18.  EFFECT OF LAWN SPRINKLING  ON VARIOUS  SOIL
                          CHARACTERISTICS
Location       pH  Calcium  Potassium Phosphate  % Moisture Particle size
                                                  distribution
sprinkled 6.2
#6
non-
sprinkled 6.6
#7 sprinkled 5.3
non-
sprinkled 5«^
NOTES:
MH - Medium high
M - Medium
L - Low
VL - Very low
MH M
MH M
VL VL
L VL
VL
VL
M
M
8.7
9.6
11.4
13.9
Pine -
very fine
sand
Fine -
coarse
•» « o M.-3
sand
These level designations are relative to normal
values found in the soils in this area and were
assigned by the University of Connecticut Agronomy
Testing Laboratory.
Reuse for lawn sprinkling may present a possible hazard
because  of  the greater accessibility to the recycled wash
water, should any pathogens be present.  This hazard could
be eliminated by a suitable underground discharge system.

Water Savings

Waste wash  water (bath and laundry) was reused for toilet
flushing and/or lawn sprinkling in homes #6, w7, and wo.
Data for each specific type of, reuse are shown in Table
19. for  each of the three home's.  In home #8, wash water
was recycled exclusively for toilet flushing.  In home #6,
it became necessary to reconnect the water closet to the
city water  supply during the months of August and September
in order to make changes in the filtration and pressuriza-
tion system.  During that period, wash water was reused
exclusively for lawn watering through use of the filter
by-pass  line which incorporated a heavy duty Cuno car-
tridge filter.

The maximum amount of water savings attainable is equal  to
the water normally used for toilet flushing and/or lawn
sprinkling.  In actual operation the water savings will  be
diminished  by an amount equal to the supplemental feed-


                               51

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                        Table  19.    WASH WATER RECYCLE  SYSTEM:    FLOW REDUCTION -SUMMARY
ui
Household
and
Phase I & III
average inlet
#6
190O Ipd
#7
715 Ipd
#8
735 Ipd
Type
of
re -use
toilet
flush.
toilet
& lawn
lawn
sprink.
toilet
flush.
toilet
& lawn
toilet
flush.
Net
storage
volume
liters
455
455
455
305
305
322
Toilet Bath & laundry
Ipd Ipd
Phases
I & III
433
448
448
21O
210
286
Phase
II
266
337
-__
193
204
194
Phases
I & III
662
662
662
282
282
195
Phase
II
750
794
732
265
334
262
Lawn
sprin-
kling
Ipd
	
106
402
	
15.5
	

Feed
water
Ipd
15.5
44.5
22.4
10.6
4.9
18.2
Tank
over-
flow
Ipd
5OO
396
352
83
119
86
Overall
average0
Average flow
reduction1*
Ipd
432
510
380a
189
220
268
(176)
305
Ipcd
43.7
51.5
38. 4a
37.8
44.0
65.4
(42.9)
44.0
%
red.
23
27
20a
26
31
36°
(24)
26
                Not included in overall average,  atypical reuse system.

                Note on calculation- procedure - Hones #6, 7 and 8 had reduced flow toilets and showers during Phases II
                but not during  Phases I and III.   To put the data on the same bases with no reduced flow fixtures during
                all phases,  the following was done:
                    - Effects- of  reduced flow showers were neglected.

                    - The flow reduction possible was assumed to be the average water used for toilet flushing during
                      Phases  I and III, plus any lawn watering in Phase II, minus the average feed water required in
                      Phase II.  The. feed water requirement could be higher but the effect is probably small unless
                      there is insufficient bath and laundry water to provide for conventional toilet flushing.  See
                      note c  below regarding home #8.


               °For hone  #8,  the bath and laundry water is not sufficient  to provide for flushing conventional toilets.
                In addition to the procedure outlined under note b, flow reduction was calculated by another procedure.
                The flow  reduction possible was taken as the bath and laundry water available during Phase II minus -the
                tank overflow.  The flow reduction values resulting from this assumption are shown in parentheses.
                These values  are thought more appropriate for hoae #8 and  were used in calculating the overall averages.

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water required due to both short-term and long-term im-
balances in supply vs. demand.   In homes#6 and #7, a
comparison of wash water supply  and water closet demand
shows a substantial surplus of wash water available.  In
home #8, the supply deficit observed during the control
period was converted into a surplus during the test
period by the incorporation of dual-flush toilet devices,
thereby substantially reducing water closet demand.  In
all three homes, the supplemental feedwater requirements
averaged only 5$ of the total water reuse requirements.

Average flow reductions (water savings) are also presented
in Table 19.  The overall average water savings for toilet
flushing and/or lawn sprinkling  was 305 Ipd.  The average
savings for toilet flushing reuse only was 266 Ipd.  The
incorporation of lawn sprinkling as a supplemental reuse
mode in homes #6 and #7 increased the water savings by 16$
to 18$.  Greater flow reductions could be achieved by con-
verting lawn sprinkling from a manual to an automatic
operation through the inclusion  of a high-level control
system similar to the low-level  control system previously
described.  The overall average  flow reduction, on a per
capita basis, was 44.0 ipcd.  The average percentage re-
duction in total water consumption for all three recycle
systems was 26$.

Additional Benefits

The reuse of waste wash water for toilet flushing and/or
lawn sprinkling provided tangible benefits to two of the
three homeowners above and beyond the savings in water
consumption.  The recycle system, by minimizing the surges
in outflow to the septic system  associated with laundry
and bath discharges, as well as  by reducing total waste
flow, allowed the septic tank and soil absorption system
to operate more effectively.

In both homes #7 and #8, the septic systems performed poorly
prior to recycle system installation.  In home #7, the normal
annual septic backup and associated odors were noticeably
absent despite record rainfalls  during the year.  Inspec-
tion of the septic system at the end of the test period
indicated all lines were clear with no sign of clogging or
backup.  In home #8, before and  after installation of the
recycle system, the household experienced difficulty
laundering multiple washes (in succession) without causing
the septic system to back-up and overflow the standpipes.
As a result, frequent trips to a commercial laundromat
were necessary.  This difficulty was not experienced during
the test program.


                               53

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SUB-SYSTEM DEVELOPMENT AND PERFORMANCE

Storage System

On the basis of criteria such as corrosion resistance,
adaptability and ease of handling, and cost per unit
volume, Nalgene heavy-duty conventional polyethylene tanks
were selected.  These plastic storage tanks are also trans-
lucent, thereby enabling water levels inside the tank to
be monitored by the homeowner.  Selection of tank capacity
was limited by considerations of space and cost.  Based on
daily monitoring of the magnitude of both flush toilet and
bath/laundry usage, as well as their relative balance or
imbalance, 380 liter (100 gallon) tanks were deemed ade-
quate for homes #7 and #8, and a 570 liter (150 gallon) tank
was selected for home #6.  Standard 455 liter galvanized
pneumatic tanks were too difficult and costly to adapt, and
custom-made galvanized tanks were more costly and difficult
to handle than those selected.  Two-hundred and eight liter
(55 gallon) steel drums with polyethylene liners were eco-
nomically attractive but were not considered the most con-
venient for the first prototype test units.

A sketch of a 380 liter polyethylene storage tank, with
required modifications, is shown in Figure 16.  The vented
tank was provided with a 3.2 cm (1-1/4 ) side bottom out-
let bulkhead fitting of PVC.  A side bottom outlet was
selected, as opposed to a bottom drain, to explore the
benefits of using the storage system as a settling tank.
2.5 cm (l") and 3.8 cm (1-1/2") PVC bulkhead fittings were
installed in the 0.95 cm LPE (linear polyethylene) cover to
accommodate the laundry and bath wastes, respectively.  A
3.8 cm overflow fitting was located approximately 12.5 cm
below the cover.  Design calculations indicated that a 9.2
cm allowance would have been sufficient to provide for a
continuous inflow of 115 1pm.  The tank rested on a sheet
of 2.5 cm plywood and was elevated with concrete blocks to
allow the overflow to gravity drain into the building main
drain to the main septic tank.  A check valve was incorpor-
ated into the overflow line- to preclude backup of the septic
system into the storage tank.

The storage tank was also provided with a low-level control
system (LLCS) in order to ensure an adequate water supply
at all times.  The LLCS consisted of a solenoid controlled
feed line valve activated by a sump pump type float switch
installed as shown in Figure 17.  A specially designed float
rod assembly was fabricated for this application (see Fig-
ure 18).  The LLCS was designed so that the feedwater line
would be activated with the water level approximately 7.6


                               54

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                 3/4" SOLENOID
                VALVE
                          CONCRETE
                          BLOCKS
                                                      SUMP PUMP
                                                      FLOAT SWITCH
                                                      (INSTALLED UPSIDE
                                                      DOWN)
                                                      FLOAT ROD
                                                      ASSEMBLY
                                                       PVC BULKHEAD
                                                       FITTINGS
                                                         BASEMENT
                                                         FLOOR
Figure  16.   Polyethylene  storage tank
                              55

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         Figure 17 •  Low-level control system


cm above the top of the outlet pipe.  This Is a point where
sufficient water is still available to handle 3 to 4 sim-
ultaneous toilet flushes.  De-activation of feedwater supply
occurred with the water level at 12.7 cm above the top of
the outlet pipe.  The effective wash water storage capacity
of the tank was thus decreased by 28 to 47 liters.

The size of the storage tanks proved to be adequate in terms
of collection capacity required prior to reuse as evidenced
by the relatively small quantities of fresh feedwater re-
quired.  The low-level control system performed reliably
and maintained an ample supply of water in the tank at all
times for toilet flushing and/or lawn sprinkling reuse.
In homes #6 and #7, the tank overflow was capable of hand-
ling simultaneous bath and laundry inputs with the water
level remaining well below the top of the tank.  In home
#8, the overflow initially did not function properly due
to a partially clogged septic system and improper installa-
tion (insufficient slope from tank to soil pipe location).
Subsequent cleaning of the septic system and increasing
the pitch of the overflow line allowed for satisfactory
overflow operation for the remainder of the test period.
                             56

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1/2"
BULKHEAD
FITTING
                              1/2"PVCPIPE
                          'T-'20-1/2" LONG FOR 100 GAL TANK 2T LONG FOR ISO GAL TANK
                              3/4" X 1/2" ADAPTER. JKS

                              3/4" PVC PLUG. NPT W/1/4" TAPPED HOLE
                              1/2"PVCTEE.NPT


                              12" L BRASS FLOAT ROD. 1/4" -30
                                   STD.4"X6"FLOAT
  Figure  18.   Low-level  control  float  rod assembly

                                      57

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The side-bottom outlet permitted a substantial fraction of
the suspended solids to settle out and accumulate at the
bottom of the tank over a period of time.  The obvious ad-
vantage of using the storage container as a settling tank
is the decreased load on the filter and associated reduc-
tion in filter operating costs, particularly for the car-
tridge filters.  The accumulated sludge has to be drained
or pumped out periodically in order to maintain this ad-
vantage.  An alternate design, more suitable for use with
a diatomite filtration system, is to provide for bottom
discharge, allowing virtually complete drainage and pre-
cluding any significant sludge build-up.  A tank with a
conically-shaped bottom (commercially available in heavy-
duty polyethylene) would be ideal for this design modifica-
tion.  A polyurethane support could be molded at nominal
cost.  Without sludge separation by settling, the load on
the filter would be increased and backwashing and pre-
coating would probably be required at least twice as often.
However, the increased filtration costs should be offset
by reduced disinfection requirements.

Leaks developed at the tank outlet location in both homes
#7 and #8.  In both cases, threaded plastic (FVC) fittings
were cracked by the application of excessive torque to a
mating metal reducing bushing or adapter during installa-
tion.  The connections were subsequently made up using all
FVC fittings and no further leaks were observed.

Filtration System

The two primary reasons for the incorporation of a filtra-
tion system into the wash water recycle system are:

     (l) To remove debris such as large dirt particles
         and lint that might adversely affect operation
         of the pressurlzation system or toilet control
         valves.

     (2) To provide an effluent of sufficient clarity
         (as indicated by turbidity and suspended solids
          levels) to be generally acceptable to the user.

The first function can be readily accomplished by a simple
basket-type strainer.  The second function obviously re-
quires a more sophisticated and costly filter.  The cri-
teria of aesthetic acceptability is a highly subjective
and variable one, and may be amenable to public condition-
ing and education.  The toilet flushing water standards
suggested in Reference 1 were used as tentative guidelines

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and included a recommended maximum turbidity level of 20
turbidity units.

In the search for an optimum filtration  system, the desired
degree of filtration must be tempered  by considerations of
economic feasibility and convenience to  the homeowner.  In
general, the finer the filtration, the more costly the op-
eration.  After a survey of  available  filter types, and
discussions with various manufacturers,  two alternate
approaches were selected for evaluation.  Cartridge filters
were incorporated into the recycle systems of home #6 (8
months) and home #7 (12 months).  Diatomite filters were
installed in home #8 (12 months) and home #6 (3 months).
The performance of each filter was continually monitored
and evaluated in terms of effluent clarity (turbidity),
suspended solids levels and  filter capacity.  In addition,
the homeowner recorded, as shown in Figure 19, such data
as filter pressure drop, storage tank  level, and quantity
of disinfectant used.  Information relating to both routine
maintenance and operational  problems was  also noted.  Tur-
bidity and suspended solids  analyses were performed in
accordance with the standard methods recommended in Refer-
ence 9.

Diatomite Filter

The specific unit selected was a Diaclear LP-18 diatomite
filter, and is shown in Figure 20 with the pagoda-shaped
filter septum removed.  The  septum is  fabricated from
woven polypropylene and has  a filtering  surface area of
1.6? sq m.  In order to facilitate backwashing, the filter
was modified by incorporation of a PVC reciprocating slide
valve as illustrated in Figure 21.  Prior to filter opera-
tion, the filter is pre-coated by circulating a pre-mixed
slurry containing approximately 0.7 kg of diatomite
through the filter, the slurry being educted through a
separate valve controlled feed port (see  Figure 21).  The
average time required for pre-coating  the filter was approx-
imately 5 minutes.  The pre-coat procedure was performed in
accordance with the manufacturer's recommendations and
follow-up consultations, and was considered optimum for
this application.  Changing  the position  of the slide valve
reverses the flow through the filter and  allows the dirty
filter cake to be backwashed out to the drain with the use
of 75 to 95 liters of filtered wash water.  Fresh water for
backwashing can be fed in through the  same connection as
used for pre-coating.  This  particular filter model was
selected because of the relative ease  with which it can be
backwashed.  Sand filters were not considered because of the
large flow rates (75-115 Ipm) normally required for back-


                                59

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                                         HOME NO.	/PHASE JH
DATE
TIME
METER
READINGS,
GALLONS
WATER
CLOSET
BATH
LAUNDRY
COLD
HOT
COLD
HOT
FEED WATER
INLET
FILTER AP, INCHES HG
FILTER
RENEWAL
BACKWASH
VOL. GAL
TIME REQ'D, MIN.
STORAGE LEVEL
SAMPLE
NUMBER
STORAGE TANK
TOILET TANK
NUMBER OF OCCUPANTS
















































































































O
   COMMENTS:
           Figure 19.  Typical data  collection form - recycle system

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washing of systems that would be suitable In size for
home use.
           Figure 20.  Diaclear dlatomite filter

                               61

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Figure 21.  Diatomite filtration system: installed




                            62

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Preliminary testing of this filter unit without  the normal
recirculation gave poor results.  In  the absence of flow,
the filter cake rests at  the bottom of the filter.  Each
time the jet pump is activated,  the filter cake  is re-
applied to the system, but sufficient time apparently elap-
ses to permit a significant portion of the wash  water to
pass through unfiltered.  Normal  recirculation rates are in
the order of 40-80 Ipm/sq m filter area.  In this applica-
tion, recirculation levels of  this magnitude would be im-
practical in terms of operating  costs and noise  levels.
Hence, a compromise solution was  sought, and a 1/30 HP re-
circulation pump was incorporated which did provide accep-
table effluent clarity after several  hours of recirculation.
The recirculation pump required  a by-pass line and check
valve in order to preclude cavitation during pressurization
of the; filtered wash water.

A diatomite filter was first evaluated in home #8, with the
filtered wash water reused exclusively for toilet flushing.
Sears standard swimming pool grade diatomaceous  earth was
utilized in all but one instance.  For the third filtration
cycle, a much finer grade (Johns-Mansville supercel) was
used for a comparative evaluation.  Table 20 summarizes the
filter performance data for homes #8  and #6.  The volume of
wash water processed and  number  of days is tabulated for
each filtration cycle.  Backwashing was performed when the
filter pressure drop, as  indicated by the pump vacuum gage,
exceeded 64 cm Hg.  The typical  variation of filter pressure
drop with time observed for this  type of filter  is shown in
Figure 22.  After the first few  days  of operation, a pla-
teau of /^ 40 cm is reached and maintained until the last
few days of the cycle.  The dropping  and re-application of
the filter cake by temporary shutdown of the recirculation
pump can result in a temporary lowering of the pressure
drop with a concomitant extension of  filter life.

In home #8, the filter was backwashed prematurely during
the 2nd, 3rd, 5th, and 6th cycles.  The 2nd and  5th cycles
were prematurely terminated to accommodate replacement of
the recir.culating pump.   The first recirculating pump de-
veloped excessive noise which  was later traced to a defec-
tive s tat or winding.  The second  pump developed a leak at
the shaft seal due to the corrosive effect of excessive
chlorine residuals discussed in a later paragraph.  A seal-
less magnetic drive 1/30  HP pump  was  used, for the remainder
of Phase II.  No further  problems were encountered.  The
3rd cycle was terminated  as a  result  of the poor perform-
ance being obtained with  the supercel grade of diatomaceous
earth and the 6th cycle due to a  penetration of  the filter
septum.  The wire form on which the filter septum is
positioned snapped at a welded Joint  (which was  probably

                               63

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weakened  by overchlorination during initial testing) and
subsequently penetrated  the polypropylene  bag.   Some corro-
sion  of the interior surfaces of the filter housing was
also  noted in home #8.   A  change in materials of construc-
tion  for  both the wire form and filter housing from galvan-
ized  to stainless steel  or a suitable plastic is apparently
indicated for this application
Table  20.   DIATOMITE FILTRATION
- PERFORMANCE  DATA
HOME #8
Length
of
Time Period
Period (days)
1
2
3
4
5
6
7
124
50a
I6a
56
I6a
7a
83
Diato
uradel
std
std
Super -
eel
std
std
std
std
mit
oat
Wt.
0.
0.
0.
0.
0.
0.
0.
e
Volume of
Turbidity
levels, ppm

68
68
68
68
82
82
82
23,700
11,700
3,350
14,500
2,690
1,100
15,500
14-30
19-29
40-60
18-40
40
110
15-39
Toilet
13-30
25
20-60
25
90
15-29
Suspended
solids, mg/1

Storage Toilet
12-21 15-25
23-32 29
23-45
66 36
10-38
HOME #6
Time
Period
1
2
Length
of
Period
(days)
49
57
Diatomate
pre-coat
aradeiwt. .K-K
std
std
0.
0.
82
82
Volume of
wash water
processed,
Tit ere /eye
12,8oob
14,000C
Turbidity
levels. pom
Suspended
noli fin. mer
A
. Storage we/lawn Storage we/lawn
23
22
19
20
12
15
20
19
  Baclcwashed prematurely for reasons other than excessive filter
   pressure drop (see text).

  bReused primarily for lawn sprinkling.

  GReused primarily for toilet flushing.

-------
cr\
                                            FRAM CARTRIDGE FILTER
                                                       AMF-CUNO CARTRIDGE FILTER
                 Figure 22.   Filter pressure drop vs  time

-------
Three complete filtration cycles were obtained during Phase
II.  The volume of wash water processed per cycle ranged
from 14,500 liters to 23,700 liters, with a corresponding
cycle life of from 56 to 124 days.  The observed spread in
the data probably reflects the effect of sludge build-up
at the bottom of the storage tank.  The sludge was pumped
out of the tank at the end of period #5 by simultaneous
stirring and dilution with supplemental feed water.  The
implications for storage tank redesign were discussed in a
previous paragraph.

In home #6, two full filtration cycles were obtained.  The
filter capacity ranged from 12,800 to 14,000 liters of
wash water, with corresponding cycle lives of from 49 to
57 days.  The relatively short cycle life, as compared
with home #8, is a consequence of the much greater daily
water consumption in home #6.

Turbidity and suspended solids levels were determined at
both the storage tank and water closet locations.  In gen-
eral, the filtered wash water had a slight greyish cast as
compared with tap water.  At the lower turbidity levels
the color was scarcely noticeable.  During normal operation,
the turbidity of the water recycled to the water closet
ranged from 13 to 30 ppm in home #8, and 19-20 ppm in home
#6.  Suspended solids levels ranged from 15-25 mgA in
home #8 and 19-20 mgA in home #6.  The 5th and 6th filtra-
tion cycles in home #8 were not included with the data
summarized above due to the developing loss of Integrity
of the filter septum.  The variation in the turbidity and
suspended solids data reflects, to some extent, the time
interval between sampling and the most recent bath and/or
laundry input, as well as influent turbidity and suspended
solids levels.  Although the effluent turbidity levels
ranged somewhat higher than the proposed design criteria,
they were found to be aesthetically acceptable.

COD (chemical oxygen demand) levels for the filtered, dis-
infected wash water were also determined and ranged from
53 to 85 mgA.

Cartridge Filters

As an alternate approach, two different cartridge-type
filters were evaluated during the test program.  Since no
circulation was required, the systems incorporating these
filters were inherently less complicated.  One of the
cartridge filters selected was an AMP/Cuno CG 4DC-1 stain-
less steel filter shown disassembled in Figure 23.  Four
cartridges surround the internal centerpost.  The model
was selected primarily on the basis of ease of maintenance,

                              66

-------
Figure 23.  AMF/CUNO cartridge filter

-------
availability, corrosion resistance, and the relatively large
number of cartridge types and porosities available.  Micro-
klean depth-type, disposable cartridges (wool fiber, phenolic
resin) with nominal solids removal down to 5 to 25 microns,
and Cuno-Cel surface type disposable cartridges (pleated
cellulose) with a nominal solids removal down to 10 microns
were chosen for testing.

A Pram MCM epoxy-coated steel filter shown in Figure 24 was
the other unit tested.  This model was selected primarily
on the basis of its low initial cost.  The filter is de-
signed to accept a single large cartridge of the surface
type (pleated cellulose), with nominal solids removal down
to 5 to 15 microns or the depth type (glass fibers), with
solids removal down to 10 microns.  Both the Pram and AMP/
Cuno filters were provided with vent and drain plugs.

Pram Filter -

A Pram MCM filter was tested in home #6, with an AMP/Cuno
1M filter installed in the by-pass line.  Cartridges were
replaced when the filter pressure drop exceeded 64 cm Hg.
The typical variation of filter pressure drop with time is
illustrated in Figure 22.  The pressure drop is seen to
increase very gradually and remains relatively low through-
out most of the filtration cycle.  Toward the end of the
cycle, the rate of increase is substantially accelerated.
Cartridge replacement was readily accomplished by the home-
owner in approximately 10 minutes.  Table 21 summarizes
the filter performance data for home #6.

The volume of wash water processed by the surface-type
cartridges progressively diminished from 15,650 liters to
5,200 liters, with a correspondingly shorter cartridge life.
This apparent diminution in filter capacity was presumably
due to the gradual build-up in and partial carryover of
sludge at the bottom of the storage tank.  The sludge carry-
over was apparently enhanced in periods 7, 8, and 9 by the
supplemental reuse of wash water for lawn sprinkling.
Hence, periods 1 and 5 would be indicative of filter car-
tridge capacity if the sludge were periodically removed
every 3 to 4 months by draining or pump-out.  Periods 7, 8,
and 9 reflect conditions of filtration without the aid of
a settling tank.

A single 10-micron depth-type cartridge was tested and
became clogged after having processed only 3305 liters
(10 days) of wash water.  Due to a delay in the procure-
ment of additional extended surface cartridges, the by-
pass filter was operated for a total period of 39 days.


                               68

-------
'Mi

-------
Table  21.
            PRAM MCM CARTRIDGE FILTER/CUNO IN By.-PASS PILTER
                          PERFORMANCE DATA
                                    Turbidity
                   Cartridge  Volume    levels, ppm
Time    Cartridge       life,    processed
period  description	days
                                                    Suspended
                                                           , me: A
 ._	         efflu-
llters/cyc.influent  ent
                                                          efflu
                                                   influent  ent-
  1     C-744, 5        52
       micron, ex-
       tended sur-
       face

  2     C-729, 10       10
       micron, depth
       type
  3     Cuno by -pass,     3
       10 micron depth
  4     Cuno by -pass,    11
       25 micron depth

  5     Cuno by-pass,    25
       heavy-duty

  6     C-744-15, 15     46
       micron, exten-
       ded surface

  7     C-744-15, 15     22
       micron exten-
       ded surface

  8     c-744-15, 15     12
       micron, exten-
       ded surface

  9     c-744-15, 15      8
       micron, exten-
       ded surface
                             15,650



                              3,305


                               855

                              3,100

                              6,200

                             12,000


                              9,450


                              5,150
           70-90  40-55    49-67  26-36
            90
50
            90     68

           85-90  78-85

            85     82


            75     55


            90     60


            85     60
64





68

66

52
29




60

64

29
        65    32
                              5,220    110     65     66      33
Depth-type cartridges with nominal ratings of 10 to 100
(heavy-duty) microns were used successively, and evidenced
respective filter capacities  of 855 to  6200 liters  (3 to
25 days).  Two  Cuno 1M filters equipped with heavy-duty
cartridges should be equivalent to the  Pram MCM filter in
terms  of filter cartridge life.

Effluent turbidity levels for C-744 (extended surface)
cartridges ranged from 40 to  65 ppm, representing turbidity
reductions of from 27 to 50$.   Filtrate suspended solids
levels ranged from 26 to 36 mg/1, corresponding to  per-
centage reductions of from 44 to 50$.   The heavy-duty
by-pass filter  achieved negligible reductions in turbidity
and suspended solids levels.   As was the case with  diatomite
filtration, the filtrate had  a slightly greyish cast.
                                  70

-------
AMF/Cuno filter -
A C^no stainless steel cartridge  filter received testing in
home #7.  Replacement of the filter  cartridges was easily
accomplished by the homeowner in  approximately 10 minutes.
Variation of filter pressure drop with time is shown in
Figure 22.

Filter performance data for home  #7  is summarized in Table
22.  The capacity of the 10-micron depth-type (F2278-C1)
cartridges progressively decreased from 11,000 liters (52
days) for period #3 to 4370 liters (18 days) for period #5
due to the sludge build-up and  carry-over effect noted
earlier.  Based on a comparison of the average weight pick-
up of the filter cartridges with  the observed reduction in
suspended solids levels, it is  estimated that approximately
2/3 of the wash water suspended solids settled to the bottom
of the storage tank during normal operation.  The sludge was
pumped out of the tank at the end of period #7.  The per-
formance of the last two sets of  cartridges, in terms of
filter capacity, was markedly improved.  In period #9, the
improved G78 cartridges attained  a filtration capacity of
22,450 liters (108 days), higher  than any other cartridge
tested.  As anticipated, the 5-micron depth-type cartridges
were able to process only one -half the amount filtered by
comparable 10-micron cartridges.  The 10-micron extended
surface cartridges exhibited capacities intermediate be-
tween the original and improved depth-type cartridges.

Effluent turbidity levels for the 10-micron depth-type
cartridges ranged from 30 to 95 units, equivalent to tur-
bidity reductions of from 62 to 80$.  Effluent suspended
solids levels ranged from 3^ to 68 mgA, corresponding to
reductions of from 63 to
The extended surface cartridges produced similar average
effluent turbidity and suspended solids levels.

Filter Performance Comparison

Each filter system tested allowed for satisfactory toilet
flushing  and lawn sprinkling operation.  The major perfor-
mance differences between the filters were in the areas
of filter capacity or life, and quality of the filtrate in
terms of turbidity and suspended solids.  Filtrate quality
is essentially an aesthetic criteria involved in the promo-
tion of homeowner acceptance.  Filter capacity is important
primarily because of its impact upon operating costs as well
as homeowner maintenance requirements.
                                71

-------
            Table 22.  AMP/CUNO CG4-DC1 CARTRIDGE
                     FILTER PERFORMANCE DATA
Cartridge Volume
Time Cartridge life, processed
period description davs liters /eye
1


2


3


4


5


6


7


8


9


F-2278-cl,
10 micron,
depth-type
F-2278-B3, 5
micron, depthr-
type
F-2278-cl, 10
micron, depth-
type
F-2278-cl ; 10
micron, depth-
type
F-22878-F2, 25
micron, depth-
type
38285-32, 10
micron, surface
type
078 -c-1, 10
micron, depth-
type
38285-32, 10
micron, surface
type
G78 -c-1, 10
micron, depth-
type
39a


26


52


35


18


30


34


49


108


4,950
7

4,750


11,000


7,600


4,370


6,450


7,400


12,600


22,450


Turbidity
, levels, com
i influent
220-280


150


175-280


205-300


190


165-200


170


70-130


90-160


effluent
135-140


60


40-70


40-80


95


46-60


65-95


50-60


30-65


Suspended
solids, mg/1
prrxu-
influent ent
—


92-97 38-44


110-193 36-68


168-195 49-66


135 92


95-135 33-38


—


60-90 39


93-158 34-51


cartridges replaced prematurely for inspection.
                                  72

-------
Table 23 summarizes filter  system performance for each of
the three units tested.  The diatomite filter achieved the
best overall performance.   The filter provided an average
capacity of approximately 17,000 liters per cycle and a
corresponding average backwashing interval of about three
months.  The average filtrate turbidity and suspended
?° l2S ifv!ls,?f ?? ppm and 21 ""SA* respectively, achieved
by the diatomite filter, were judged to be quite satisfac-
tory in terms of aesthetic  acceptability.  The two car-
tridge filters, roughly equivalent in performance, pro-
cessed 74 to ob> as much wash water per cycle as did the
diatomite filter, while permitting effluent suspended
solids and turbidity levels approximately two to three times
higher.
      Table 23.   FIHTER SYSTEM PERFORMANCE SUMMARY
Average
volume
Filter processed,
system liters /cvc .
Dlaclear
LP-18
Diatomite
Pram MCM
15 micron
surface-
type
AMP/Cuno
CQ4-DC1
10 micron
17,000


12,600



15,000


Equivalent
filtration
period,
days
86


48



71


Average
effluent
turbidity
levels. Dom
23


60



62


Average
effluent
suspended
solids. me A
21


31



43


Annual
operating
costs,
I/year
16


43



40


depth-type
Disinfection

It was anticipated at the start of the program that some
provision for disinfection of the stored wash water would
have to be made in order to control odors as well as to
prevent health hazards.  In order to establish disinfec-
tion requirements, several samples of non-disinfected wash
water were collected one to two weeks after installation of
two of the recycle systems, and were analyzed for colifortn
levels.  The most probable'number of total collforms (MEM)
ranged from  <3 to 100/100 ml for home #8 and from 160 to
1000/LOO ml for home #7.  After four to five weeks  holding,
bacterial growth had increased by two to three orders of
magnitude, and septic odors were detected.  The data thus

                                73

-------
indicated that normally used amounts of both laundry deter-
gents and bleach (Clorox) were clearly inadequate in terms
of bacterial growth inhibition.

Based primarily on considerations of cost and disinfecting
power, chlorination was selected as the best means of des-
troying pathogenic and odor-causing bacteria.  The use of
alkyl ammonium chlorides such as Roccal are not suitable
for this application since they are neutralized by soaps and
anionic detergents.  A preliminary evaluation of the chlorine
demand of untreated wash water samples was made for homes #7
and #8.  Freshly collected wash water required chlorine
concentration levels of /*- 5 mg/1 to provide 1 hour chlorine
residuals 2 0.5 ppm.  Untreated wash water samples collected
after one to two months of storage showed higher chlorine
demand levels, ranging from 10 to 15 mg/1.
  i
Two different techniques were utilized for disinfection of
the stored wash water at the required dosage levels.  Both
represent a relatively simple and inexpensive means of
chlorination.  The first of these provides for the con-
tinuous introduction of diluted laundry bleach (NaOCl) with
the use of an air lift feeder as illustrated in Figures 25
and 26.  An alternate approach utilized an inexpensive
chlorine tablet feeder designed for above ground pools
(see Figure 27).  Both calcium hypochlorite tablets and the
more slowly dissolving chlorinated isocyanurates were eval-
uated in conjunction with this feeder.  Both approaches
are capable of providing pre-determined chlorine dosage
levels based on average daily throughput rates.  Specific
dosage (concentration; levels at any given time may vary
considerably, and will depend on such factors as (a) daily
and weekly wash water supply and water closet demand pro-
files, (bj effective tank capacity, and (c) amount of dirt
and sludge present in storage tank and filter at any time.

The performance of each feeder was periodically monitored,
and samples were taken for analyses of chlorine residual,
odor, and coliform count.  Corresponding chlorine dosage
levels were also determined.  Chlorine residuals were de-
termined by the Ortho-Tolidine method.9  Testing for the
coliform group was carried out by the multiple-tube fer-
mentation technique, the results of which were expressed
in terms of the Most Probable Number (MPN) per 100 ml.9
Operation and performance details are given below for each
of the methods of disinfection.      '

-------



Figure 25.  Air lift Clorox feeder

-------
Figure 26.  Air lift feeder installation
                      76

-------
Figure 27.  Chlorine tablet feeder

-------
Air Lift Clorox Feeder

An air lift feeder was installed and tested in home #7.  A
standard aquarium air pump forced air through flexible
plastic tubing partially filled with the bleach solution,
via a tee arrangement, and lifted droplets of .bleach up
into the storage tank through 0.64 cm OD (0.32 cm ID) poly-
ethylene tubing.  The chlorine dosage rate was controlled by
adjusting either the feed rate or the strength of the bleach
solution (0.85 - 1.7$ NaOCl).  The feed rate was governed
by the level of bleach inside the main feeder bottle (in
which the bubbler was immersed).  The average feed rate was
approximately 25 cc/hr, corresponding to chlorine dosage
levels of from 20-25 mg/1.  The bleach solution was main-
tained at the desired level with the aid of a feeder set-up
as shown in Figure 26.

The Clorox reservoir consisted of an air tight (screw cap
closure) plastic aspirator bottle, filled with bleach solu-
tion with flexible plastic tubing attached.  The tubing was
inserted into the bleach solution primary feed container
(Figure 25) to the desired depth.  As long as the end of the
tubing remained immersed in the bleach solution, no transfer
of bleach took place due to the vacuum which existed in the
Clorox reservoir bottle.  When the level of bleach in the
primary container dropped so as to expose the end of the
tubing, the vacuum was broken and gravity flow took place
with air bubbles displacing the fluid transferred.  The flow
continued until the end of the tubing was no longer exposed
and the vacuum re-established.

Replenishment of the diluted laundry bleach was required
about every 30 days.  The yearly requirement for household
laundry bleach (5$ hypochloritej is estimated at 42 liters
(ll gallons).

The data in Table 24 show that the air lift feeder, once
properly adjusted, provided satisfactory performance In
terms of odor control and germicidal action.  In general,
chlorine residuals of from 0.15 to 0.5 mg/1 were main-
tained in the water closet tank throughout the test period.
As expected, chlorine residuals in the storage tank showed
a wider variation, ranging from 0.2 to 5 ppm.  As long as
measurable chlorine residuals were maintained, no unpleas-
ant odors were detected at the water closet or storage
tank location, and the coliform counts were essentially
negative ( £ 11/100 ml).  Fortunately, the wash water was
disinfected at pH values near neutral, which is favorable
to a high level of disinfecting efficiency.

-------
Table 24.  CLOROX AIR LIFT FEEDER  -
          PERFORMANCE DATA
Average Total
chlorine Chlorine Coliform
dosage residual, . count,
Date level, mcc/l me A Odor MPN/100 ml Remarks
11/22

11/30
12/21
3/1

3/6
3/14
3/21


3/27
3/28
4/13
4/17
4/19
4/24
4/28
5/3
5Al
5/16
5/22
6/5
6/9
6/12
6/18
6/30
0

0
0
15

10
50
20


27
27
20
10
10
28
40
20
29
10
15
10
20
25
20
35
0

0
0
0

0
0.5
0.3


0.2
0.15
0.25
0.1
0
0.25
0.5
0.15
0.15
0
0.15
0
0.25
0.2
0.15
0.1
TW₯ 160 Without disin-
fection
SS 1000
TWW 140,000
TW₯ — Feeder in-
stalled
ND
MC
ND — Incorporated
"Clorox
Reservoir"
ND
ND <11
ND
ND
ND
ND
MC < 3
ND
ND < 3
ND
ND
MS 24,000 Feeder In-
operative
ND
ND
ND < 3
ND
                    79

-------
         Table 24.  CLOROX AIR LIFT FEEDER -
              PERFORMANCE DATA-(CONT'D)
Average
chlorine Chlorine
dosage residual,
Date level, rag/1 rag A
7/6
1/12.
7/17
8/1
8A6
9/5
9/8
9/15
9/22
9/28
10/3
10A6
50
25
25
15
55
60
26
20
35
25
25
50
0.15
0.15
0.2
0
0.5
0.5
0.15
0.1
0.3
0.2
0.15
0.25
Total
Collform
count,
Odor MPNAOO ml Remarks
ND
ND
ND
MS
MC < 3
MC
ND
ND
ND
ND < 3
ND
ND




Increased
Clorox con-
centration

Readjusted
concent.
downward





aAnalysis performed on samples taken at water re-use
  location.

 Odor glossary:

     TWW - Typical wash water
      MC - Mild chlorine
      MS - Mild septic
      SS - Strong septic
      ND - None detected (equivalent to chlorinated tap
                            water)
                           80

-------
The excessively high coliform  count  of 24,OOOAOO ml noted
in Table 24 was due to the  inadvertent disconnection of
electric power to the air pump.  This rendered the air lift
feeder inoperative for several days.  Such an incident would
not occur in a permanently  installed system.

HTH Chlorine Tablet Feeder

A commercially available chlorine  tablet feeder was in-
stalled and tested in homes #6 and #8.  The feeder was first
incorporated into the diatomite  filtration system of home #8,
with filtered wash water continuously recirculated through
the feeder.  Chlorine dosage levels were controlled by (a)
adjusting the immersion depth  of the chlorine tablets, and
(b) adjusting the rate of flow to  the feeder.  HTH (calcium
hypochlorite) tablets were  first used, but problems in con-
trolling the dosage level were encountered due to its rapid
dissolution rate and incomplete  solubility  At normal recir-
culation rates, excessive chlorination resulted.  At low
flow rates, the tablets exhibited  a  tendency to coalesce in
the feeder, blocking further dissolution.  The HTH tablefes
were subsequently replaced  by  completely soluble chlorinated
iso-cyanurate tablets which dissolved at a much slower rate.
However, the chlorinated iso-cyanurates were found to be
significantly less effective than  hypochlorltes, per unit
weight of chlorine, in maintaining odor control, and higher
residuals had to be maintained (1-2 ppm).  In addition, with
normal recirculation rates  and present feeder design, the ex-
tent of tablet immersion was critical in order to avoid under
of over chlorination, making frequent adjustments necessary.

A second chlorine tablet feeder  was installed in home #6.
The set-up incorporated a solenoid-controlled return line
to the feeder.  The solenoid valve was, in turn, activated
by the Jet pump pressure switch, and admitted filtered,
pressurized wash water to the  feeder concurrently with pump
operation.  Hence, in this  case, the chlorine feed profile
coincided with the household toilet flushing pattern.  Both
the return flow rate and tablet  immersion depth were adjusted
to provide an average dosage level of 20 to 30 mgA based on
the average water closet consumption.  Due to the intermittent
type of operation, calcium  hypochlorite tablets were able to
be used successfully.  Chlorine  odors emanating from the dis-
penser were minimal.  The feeder held approximately 200 HTH
tablets, providing a replenishment interval of about 80 days.
Approximately 3.6 Kg (8 Ibs) of  HTH tablets would be required
on an annual basis.
Performance data for the tablet  feeder installed in home #6
are shown in Table 25.  During normal operation, chlorine
residuals of from 0.1 to 1.0 mg/1  were maintained.  On one


                                81

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Table 25.  CHLORINE TABLET FEEDER -
          PERFORMANCE DATA
Date
1/17
1/26
2/2
2/9
2/11
3/2
3/3
3/15
3/29
4Ao
4/19
4/26
5/26
5/31
6/5
6/7
6/9
6/13
7/13
Average
chlorine Chlorine
dosage residual,
level, rag/I mg/1
0
0
0
20
10
28
200
0
25
20
10
5
25
50
25
25
200
25
25
0
0
0
0.1
0
0.5
5
0
0.15
0.1
0
0
0.15
1.0
0.15
0.15
5.0
0.3
0.1
Odor
TWW
TWW
TWW
ND
ND
ND
MC
TWW
ND
ND
ND
TWW
ND
ND
ND
ND
SC
ND
ND
Total
Coliform
count,
MPN/ioo ml Remarks
Without disin-
fection
•«• •••
—
Installed floats-
ing basket
dispenser
—
—
Incorp. manual
recirc.
Feeder not in
service
Re -installed
dispenser
-._
—
--
< 3 Installed HTH
feeder
--
••* mm
--
Pump running
excessively
< 3
__
                   82

-------
            Table 25. CHLORINE TABLET FEEDER -
                     PERFORMANCE DATA
                         (CONT'D)
        Lverage
       chlorine   Chlorine
       dosage     residual.
 Date  level, ms A   mgA     Odor
                          Total
                         Coliform
                          count,
                         MPN/100  ml
 8/1


 10/5
20


10
 10A2     15

 10A8     20

 11/19     25
 0.3

 0.2



 0.1

 0.1

0.15
ND


ND



ND

ND

ND
Lawn sprink-
 ling only

Diatomite
 filter oper-
 ational
 occasion,  over-chlorination was  produced when the jet pump
 remained running for an excessively long period of time
 due  to clogging of the Fram filter.  Such an occurrence
 can  be prevented by the incorporation of a pump vacuum
 switch set for 65 cm Hg.  The intermittent chlorination
 provided by this tablet feeder proved to be as successful
 as the continuous (Clorox)  feeder in controlling odors and
 bacterial  growth.

 Fluid  Transfer and Pressurization

 A pump is  required to pressurize the filtered wash water
 and  make it available for toilet flushing and/or lawn
 irrigation.  A pressure range of 100 to 200 cm Hg is
 generally  considered adequate for these purposes.  An
 additional pressure differential is required (0-50 cm Hg)
 to draw  the water through the filtration system.  In
 order  to meet  these pressure requirements at flow-rates
 ranging  from 19 to 38 1pm,  a 1/3 HP shallow well Jet pump
was  selected (Flint and Walling Model C833).  The pump
was  mounted  on either a 45  or 115 liter pressure tank,
and  was  provided with an air volume control to maintain
 sufficient  air space inside the tank, as shown in Figure
                           83

-------
28.  Operation of the pump was controlled by a pressure
switch set to maintain the pressure between 100 and 200 cm
Hg.  The pump motor was rated at 115V/5.6 amps with a
starting surge of 8.6 amps.

The 1/3 HP jet pump provided reliable and satisfactory per-
formance in terms of transferring wash water through the
filter and subsequent pressurization.  The pump was capable
of handling filter pressure drops (vacuum) up to 65 cm Hg
while pressurizing the wash water to 210 to 260 cm Hg during
water closet reuse.  During normal operation, flow rates of
from  20 to 40 1pm were provided.  The pump running time was
very short, averaging about one-half minute per water closet
flush.  The air volume control worked satisfactorily in two
of the three pumps installed.  Recurrent flooding of the
pump installed in home #7 was traced to defective air volume
control fittings.  Subsequent installation of a Schrader
air valve allowed for satisfactory pump operation.  In home
#6, a leak developed at the pump inlet connection due to
improper installation of a threaded PVC adapter.  Subsequent
replacement with cast iron fittings back to the check valve
eliminated the leak problem.
                Figure 28.  Pressurization system

                                84

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                         SECTION VII


                    HOMEOWNER ACCEPTANCE
GENERAL
The continued use and success of the various water saving
devices and systems installed in the eight test homes ul-
timately depends upon acceptance by the homeowner.  The
homeowner's decision may be based primarily on socially
conditioned attitudes, or on functional criteria such as
performance, cost, and maintenance.  In order to determine
and evaluate the reactions of the people who participated
in the demonstration program, a formal questionnaire was
prepared and distributed to all adult occupants.  Despite
the relatively small sample size (a total of 16 respon-
dents), the survey did provide a clear indication of the
relative acceptability of each of the water Saving devices
tested.

A sample of the questionnaire with the tabulated results of
the survey is included in the Appendix.  A summary of the
survey results in terms of user acceptance is presented in
Table 26.  The responses were generally favorable toward the
use of all of the devices and systems tested.

It should be noted that all of the volunteer homeowners
were General Dynamics employees.  The selection of General
Dynamics employees was made in order to (a) help assure
continuance in the program throughout its entirety,  (b)
maximize exchange of information,  (c) facilitate monitor-
ing and maintenance of experimental devices and systems,
and (d) achieve better homeowner participation.

-------
         Table 26.  SUMMARY OP QUESTIONNAIRE RESULTS
 Device or               Number               Percent of responses
 system                   of                 which indicated
 tested	respondents	   user acceptance	


 Plow limiting               16                     88
 shower heads

 Shallow trap               12                     83
 water closet

 Dual-flush                  6                    100
 devices

 Toilet flushing              6                     67
 reuse

 lawn sprinkling              4                     50
 reuse
Although the possibility of biased attitudes affecting the
results of the  survey cannot be absolutely refuted,  it is
believed that the  respondents answered the questionnaire
honestly and objectively,  with any bias due primarily to
pre-conditioned attitudes  unrelated to their association
with the contractor.   The  fact that the participants were
selected on a voluntary basis does suggest a certain level
of identification  with the objectives of the program and
perhaps a greater  predisposition towards acceptance  of a
particular device  than if  chosen at random.

FLOW LIMITING SHOWER  HEADS

A total of eleven  flow limiting shower heads were  installed
in the eight test  homes.  Eight shower heads (5  homes) were
of the type which  limited  the flow to 13.3 1pm  (3.5  gpm).
Unanimous acceptance  of this particular type was indicated
in terms of providing an adequate water supply,  spray patt-
ern, and overall performance*  The remaining three shower
heads (3 homes) incorporated a 9.5 1pm (2.5 gpm) flow
limiting orifice.   Two-thirds of the respondents using
this type shower head found the device acceptable.
                                86

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SHALLOW TRAP TOILET

Shallow trap water closets were installed in six of the
eight test homes.  Eighty-three percent of the respondents
indicated that they found the  toilet performance acceptable
and would recommend it  to others.  The remaining Ytf> found
that they had to double flush  the water closet approxi-
mately 10^ of the time, and apparently Judged this to be
unsatisfactory performance.  A small increase in the water
closet flush volume, by either raising the water level or
increasing the fill rate, may  have eliminated the problem
in one of the homes.  All of the respondents stated that
they were satisfied with the appearance of the toilet and
indicated maintenance requirements were minimum.

DUAL-PLUSH DEVICES

A total of eight dual-flush devices were tested in three
homes.  All six respondents indicated that each device was
easily installed and operated. All of the people surveyed
indicated that the devices provided an adequate flush for
solids and liquids.  Two-thirds of the respondents found
the reduced flush adequate for solids as well as liquids.
Use of the reduced or  "light"  flush averaged approximately
50$ of all flushes.  The necessity of having to hold the
flush handle while the  water closet tank was being emptied
in order to effect a full flush with the Sink-bob or Saveit
device apparently did not discourage any of the users.  All
of the adult participants considered the retail price of
each device to be within reasonable limits.  Costs are given
in Table 27 in the Cost Analysis Section.

WASH WATER RECYCLE SYSTEM

Toilet Flushing

Wash water recycle systems were installed in three homes in
Southeastern Connecticut.  All six adult respondents indi-
cated that the system was manageable, simple to use, pro-
vided an adequate water supply for toilet flushing, and
performed satisfactorily.  Fifty percent considered the'
maintenance requirements minimum.  All of the occupants
indicated that there were additional cleaning requirements
for the toilet bowl with this  system due to temporary dis-
coloration or staining.  One of the six adult participants
found the reuse of treated wash water for toilet flushing
objectionable and disapproved  of the appearance of the
water.  One-third of the participants expressed concern
about odor control and  for a possible health hazard.  None
of the respondents indicated any problems due to excessive


                               8?

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foaming.  Two-thirds of the adult users indicated they would
recommend the use of this system to others.

By way of comparison, a recent public opinion survey by
Bruvold and Ward10 in the State of California showed only
5$ of the sampled population to be opposed to the reuse of
reclaimed water for toilet flushing.

Lawn Sprinkling

All four adult participants involved in the reuse of wash
water for lawn watering did not notice any obvious adverse
nor beneficial effects as compared with conventional lawn
watering.  No effect on sprinkler system operation was noted,
Both households expressed concern for a possible health
hazard.  One-half of the participants were willing to con-
tinue using this system, as well as recommend it to others.

GENERAL

Fifty percent of all respondents indicated that they real-
ized a cost savings during the test program as a result of
a decreased water or electric bill.  Seventy-five percent
of the households served by a septic system experienced a
noticeable decrease in service requirements for these
facilities during the test period.  Based on the commercial
availability of recycle systems, 44$ of all respondents ex-
pressed an interest in toilet flushing reuse, and 31$ in
lawn watering reuse.  The prices they would be willing to
spend on a recycle system ranged from $200 to $500.
                               88

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                          SECTION VIII


                         COST ANALYSIS
INTRODUCTION
Most people are interested in water pollution abatement
and are willing to encourage the spending of government
money for various pollution abatement programs.  However,
they are understandably less willing to spend their own
money for private pollution control measures when their
neighbors are not also compelled to do so, except in those
circumstances where private water supply and/or waste treat-
ment facilities are inadequate.  There is also a general
lack of interest in devices to reduce water usage in this
country as the result of generally plentiful water supplies,
rate schedules which tend to penalize water conservation,
and Indirect methods for the recovery of capital costs asso-
ciated with the construction of pollution control facilities,
Household flow reduction is not likely to become widespread
unless water users are thoroughly convinced, not only of
the desirability of using water saving devices, but also
convinced that use of these devices would not result in a
cost penalty, and could even result in a cost savings.

COST SUMMARY

Bathroom Water Saving Devices

The installed cost for each of the water saving devices
tested is shown in Table 27.  The material costs are based
on the retail prices at which these devices are currently
available to the homeowner.  It is assumed that the toilet
inserts (reduced flush devices) and flow limiting shower
heads will be installed by the homeowner.  The total annual
cost was based on amortization* of the installed cost over

*No interest was charged for determining costs in this
 study, the assumption being made that interest would not
 be a fa.ctor with the relatively small costs involved.


                               89

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the expected life of the device.  The cost of toilet inserts,
such as the Econo-Flush, Sink-Bob, and Saveit, are expected
to decrease as the market for these kinds of devices expands.

   Table 27.  COST SUMMARY - BATHROOM WATER SAVING DEVICES
Water
saving
device
Shallow -trap
flush toilet
Dual flush
devices
Sink-Bob
Econo-Plush
Saveit
Material
Cost-$
60
4
14
6
Labor
Cost-$
15
0
0
0
Installed
Cost-$
75
4
14
6
Operating
Cost-$
0
0
0
0
Expected
Life.yrs.
20
10
10
10
Total
Annual
Cost-$/yr.
3.75
0.40
1.40
0.60
 Plow limiting
 shower heads
13.3 1pm
9.5 1pm
6
8
0
0
6
8
0
0
15
15
0.40
0.53
Wash Water Recycle Systems

The cost of the various components associated with the in-
stallation and operation of the two different types of re-
cycle systems are shown in Table 28.  For the prototype
recycle systems, the installed cost of the system with the
diatomite filter is seen to be $100 higher than the car-
tridge filter system ($640 vs. ?54o), the difference
attributable to higher costs for filtration, piping, and
installation.  Storage system costs were based on the use
of a 380 liter polyethylene tank, and included provisions
for a low-level control system and tank elevation, if re-
quired.  Approximately one-half of the labor costs shown
are due to connection to the house plumbing and will vary
somewhat from home to home.

Tabulations of the operating costs associated with filtra-
tion, pressurization, and disinfection are shown for the
prototype systems.  The rather modest filter media costs
for the diatomite filter are based on the use of 3.7 kg of
diatomite per year (at $0.40Ag), and replacement of the
filter system every five years.  The relatively high oper-
ating costs for the cartridge (Fram) filter reflect an
average cartridge replacement interval of approximately two
months, and a cartridge replacement cost of $5.85.  Filter
media costs for the Cuno filter (10 micron depth cartridges)
averaged $40/yr.  Approximately 90$ of the electric power
                              90

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    Table 28.  COST SUMMARY - WASH WATER RECYCLE SYSTEMS
                       Prototype
                    Recycle  Systems
Projection for
Diatomite
filter
A. Initial cost
Storage sya» 	 $175
Filter sys.- 	 135
Pressuriza-
Disinfectant
feeder ——----- 20
Valves, pipe,
fl 4- +-•! VM-KCI — — _— _— OC
Total Mat'l
Cost- 	 R40
Labor Cost 100
Total Installed
Cost 	 - 	 $640
B. Annual Opera -
t4ng cost
Filter media 	 $3.50
Electric power — 12.00
Disinfectant — 5.50
$21.00
C. Total annual cost
Expected life
Total cost per
,rr, 	 „_ $63.50

Cartridge
filter
$175
60
115
20
80
450
$540
$38.80
1.20
5.50
$45.50
15
$81.50
recycle system
(Diatomite filter)
$70
100
85
20
-Z5L
350
$400
$3.50
7.00
5.50
$16.00
15
$43.00
aFram filter selected for cost analysis
                          91

-------
requirements for the diatomite filtration system arise from
the need for recirculation, with the remaining portion due
to pressurization for toilet flushing.  Calculation of the
power requirements was based on a 16-hour-on/8-hour-off
cycle for, the recirculation pump, and a unit electricity
cost of $0.02 per Kwh.  Chlorination costs for both the dia-
tomite and cartridge filter systems were based on maintain-
ing an average dosage level of 25 mg/1 using chlorine tab-
lets (CaOCl) at a rate of 3.6 kg per year.  Other methods
of disinfection were about equivalent in cost.  The total
operating cost for the recycle system, incorporating a
cartridge filter, is seen to be more than twice as high as
that for the diatomite filter system due to the difference
in filter operating costs of $24.50 per year.

The total annual costs were determined by amortizing the
initial costs over an expected life of 15 years and adding
the respective operating costs.  The total cost for the
.cartridge type recycle system is almost 30$ higher than the
diatomite system, as the relatively high filter media cost
for the former system overshadows its lower initial cost.

Projected costs for a mass produced, cost optimized version
of the diatomite type recycle system are also included in
Table 28.  A substantial cost reduction is projected for the
storage system based on the use of two modified 208 liter
(55 gallon) drums with polyethylene liners.  The use of pre-
assembled subsystems should decrease installation costs by
about one-half.  Due to the short pump running time required
for toilet pressurization, a less expensive jet pump should
be satisfactory.  The 42$ reduction in electric power re-
quirements shown in Table 28 reflects an anticipated cor-
responding reduction in filter recirculation requirements
which should be attainable without compromising effluent
clarity at the point of reuse.  This can be implemented by
the inclusion of an additional, limited range pressure
switch mounted on the pressure side of the jet pump which
would activate the recirculation pump.  With this set-up
the filter cake would be applied to the filter system, and
filtered water would be circulating through the lines prior
to jet pump activation.  The total annual cost for the mass
produced recycle system is estimated at $43 per year, cor-
responding to a projected cost reduction of 32$.

ECONOMIC FEASIBILITY

An assessment of the economic feasibility of the various
water savings devices tested during this program was made
in terms of their potential for cost savings through flow
reduction.  In Table 29, the cost per unit volume of flow
reduction effected by each device or system is presented

                               92

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                                            Table 29.   COST COMPARISON
Flow reduction device
Shallow trap water closet
Dual
flush
devices
Flow
limiting
shower
heads
Wash
water
recycle
system
Sinkbob
Econoflush
Saveit
13.3 1pm
9.5 1pm
Prototype
Mass-produced
Cost per unit
vol. of flow
reduction
$/1000 liters
0.15
0.02
0.07
0.04
0.08
0.22
0.57
0.39
Typical
water rates
$/1000 liters
0.16 - 0.42
0.16 - o.42
0.16 - 0.42
0.16 - 0.42
0.16 - 0.42
0.16 - 0.42
0.16 - o.42
0.16 - 0.42
Typical
sewer rates
$/1000 liters
0 - 0.13
0 - 0.13
0 - 0.13
0 - 0.13
0 - 0.13
0 - 0.13
0 - 0.13
0 - 0.13
Septic tank
system -
poor soil
$/1000 liters
...

...
<••*• MM


o.4o
o.4o
Net
Savings
$/year
$.25 to
9.80
$4.10 to
15.60
$1.72 to
9-20
$2. 40 to
10.20
$1.10 to
5.32
$.52 to
3.53
$-45.70 J
to -2.301
$-130 J
to 27.6O
$-25.20 I
to 18.20H
$19.20 J
to MJ.lol
vo
tA)
           savings per year based on water and sewer rates

      %et savings per year based on water rate and septic system cost

-------
and compared with typical water and sewerage rates.  For the
recycle systems, the basis of comparison was expanded to
include septic tanks with poor soil absorption systems.

In most instances, water supply facilities are operated as a
utility, and water use rates are adjusted to recover the
total cost incurred (operating cost plus level debt service)
plus some nominal profit.  Domestic water rates throughout
the State of Connecticut range from $0.16 to $0.42 per 1000
liters.  Water rates in the primary test area (Southeastern
Connecticut) average $0.32 per 1000 liters.  Waste treatment
facilities are normally operated by the municipal government,
and sewerage use charges are much less than the actual cost
of wastewater collection and treatment.  Usually, homeowners
are billed directly only for operational costs of sewerage
services.  Other costs, such as planning, engineering, and
construction of waste treatment and collection facilities,
are covered by initial assessment fees, bond issues, and
property taxes.  Because of encouragement by recent federal
guidelines for supplemental funding of new waste facilities,
there is a trend towards consolidation of water and waste
treatment management and towards the distribution of oper-
ating costs on the basis of water usage rather than fixed
service charges.  Typical sewerage use rates in the Connec-
ticut area range from zero for increments in use (fixed
service charges)to $0.13/1000 liters.  Treatment costs for
septic systems with poor soils are based on data from
References 11 and 12, (not updated, therefore a conserva-
tive basis).

When compared with typical water and sewer use rates, all
of the bathroom flow reduction devices listed were shown to
be economically acceptable in terms of cost savings.  In
general, the dual flush devices show the greatest potential
for cost savings, even when considered for those communi-
ties in which water rates are low to average, and sewer rates
are not based on water consumption.  The flow limiting
shower heads, despite their low cost, proved to be of less
economic value than anticipated largely because of the
rather limited water savings obtained with these devices.
At least one-half of the cost savings shown for shower
heads are attributable to a reduction in hot water heating
requirements.  The shallow trap toilet is definitely war-
ranted in terms of cost savings for new installations or
necessary replacements, since the material and installation
costs for the standard and water saving toilets are approxi-
mately the same.  Because of its relatively high cost,
however, the shallow trap toilet appears to be of limited
economic value for replacement of workable toilets.

-------
The cost analysis of the system to reuse waste wash water
for toilet flushing and/or lawn sprinkling indicates that
household recycle units become economically attractive
when septic tank systems with poor soils or other inad-
equacies are encountered.  It should be borne in mind that
the water savings indicated  ($19 to $Wyr.) apply only to
situations where existing septic systems are inadequate, or
where new septic tank installations are being planned and
incorporation of the recycle system will permit a less ex-
pensive septic system.  Comparison of the projected cost
of the mass produced version with typical water and sewer
rates indicates that the system can also effect marginal
cost savings in high water rate areas.  However, from a
strictly economic point of view, the potential cost savings
attainable in such circumstances ($18.20/yr.) is less than
one would obtain by investing an amount equal to the system
initial cost at 5$ interest.

Steadily dwindling reserves  of fresh water for domestic con-
sumption in many areas  of  the country and the continuing
emphasis on advanced waste treatment will undoubtedly en-
courage future reuse of waste water at both the household
and  community levels through higher water and waste treat-
ment rates.  Another method  of encouraging water conserva-
tion and reuse would be to make the true cost of waste
water  collection and treatment more visible to the indivi-
dual user.  This  can be accomplished if the municipality is
able to recover some or all  of the associated capital costs
by direct  charges  to the  consumer on the basis of water
usage.  Federal guidelines  on user charges show a trend in
this direction.
                                95

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                           SECTION DC

                           REFERENCES


1.  Bailey, J.R., et_ al..   A Study of Flow Reduction and
    Treatment of Waste Water From Households.   Federal
    Water Quality Administration, Cincinnati,  Ohio.  Pub-
    lication Number 11050 FKE.  NTIS Order No. PB 197-599.
    December 1969. 154 P.
       Published papers based on this report:

       a) Bailey, J. and H. Wallman.  Plow Reduction of
          Waste From Households.  Water and Sewage Works,
          118(3): 68-70,  March 1971.
       b) Bailey, J. and H. Wallman.  A Survey of Household
          Waste Treatment Systems, Journal Water Pollution
          Control Federation, 4^. (12): 2349-2360, Decem-
          ber 1971.
       c) Wallman, H.  Should We Recycle/Conserve Household
          Water?  Proceedings Sixth International Water
          Quality Symposium, Water Quality Research Council,
          April 18-19, 1972.  pp 75-76.

2.  Cabin John Drainage Basin Water-Saving Customer Educa-
    tion and Appliance Test Program.  Washington Suburban
    Sanitary Commission,  February 14, 1973.

3.  Bostian, H.E., S. Cohen, and H. Wallman.  Water Con-
    servation by the User.  Presented at the International
    Public Works Congress and Equipment Show sponsored by
    American Public Works Association, September 19, 1973
    in Denver.  Scheduled for publication in the American
    Public Works Association Reporter, June 1974.

4.  Saline Water Conversion Summary Report, 1972-73, Office
    of Saline Water, U. S. Department of the Interior.

5.  Lineaweaver, P.P., Jr., Geyer, and Wolff,  Residential
    Water Use, Report V,  Phase Two.  John Hopkins Univer-
    sity, 1966.

6.  Dunn, D.F., and T.E. Larson.  Relationship of Domestic
    Water Use to Assessed Valuation, With Selected Demo-
    graphic and Socio-economic Variables.  Journal of Amer-
    ican Water Works Association.  55, (4): 441, April
    1963.
                                96

-------
 7.  Snedecor,  G.W.,  Statistical Methods.   Fifth Edition.
    Ames,  Iowa,  Iowa State College Press, 1957.  p 91.

 8.  Chambers,  W.C.,  Chlorination for Control of Bacteria  and
    Viruses in Treatment Plant Effluents.  Journal Water
    Pollution Control Federation.  43, (2): 228-241,
    February 1971.

 9.  Standard Methods for the Examination of Water and Waste-
    water, 13th Edition.  New York, N.Y.  American Public
    Health Association, 1971.  874 p.

10.  Bruvold, W.N., P.O. Ward..  Using Reclaimed Wastewater -
    Public Opinion.   Journal Water Pollution Control  Feder-
    ation.  44.  (9): 1690-1696, September 1972.

11.  Thomas, H.A., J.B.  Coulter, T.W.  Bendixen,    and
     A.B. Edwards.  Technology and Economics of Household
    Sewage Disposal Systems.  Journal Water Pollution Con-
    trol Federation,. 3JL, (2): 113-145, February I960.

12.  U.S. Department of Health, Education, and Welfare,
     "Manual of Septic-Tank Practice," Public Health Service
     Publication No.  526, 1967.
                                 97

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                          SECTION X

                           APPENDIX



               HOMEOWNER'S QUESTIONNAIRE SUMMARY
                                                NUMBER OF
                                                RESPONSES

                                                  Yes   No

A.  FLOW LIMITING SHOWER HEAD DEVICES

    1.  Was the device attractive in appearance?   16    0

    2.  Did the fixture provide an adequate supply
        of shower water for your purposes?         14    2*

    3.  Did the fixture provide an excessive
        supply of water for your purposes?          1   3U5.
    4.  Did the device perform satisfactorily?     16    0

    5.  Was the maintenance considered minimum?    16    0

    6.  Did you require more time to shower with
        this head than with your previous
        shower head?                                2*  14

    7.  Would you recommend the use of this de-
        vice to others?                            14    2*

    8.  Did the device provide an acceptable
        spray pattern?                             14    2

    9.  Please indicate roughly what percentage
        of your total bathing was accomplished
        by showering?                               30-100$

    *9.6 1pm shower head


B.  SHALLOW-TRAP TOILET

    1.  Was the toilet attractive and acceptable
        from a decorative vi-ewpoint?               12    0

    2.  Did the toilet provide an adequate flush
        for everyday toilet use?                   10    2
                               98

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B.  SHALLOW-TRAP TOILET  (Cont'd)
C.
    3.
    4.
    5.
    (a) Was a second flush ever required?
    (b) If yes, approximately how often?
    Did the device perform satisfactorily?
    Was the maintenance required minimum?
6.  Would you recommend the shallow-trap
    toilet to others?

DUAL-PLUSH DEVICE
1.  Was this device easily operated?
2.  Did this device provide for an adequate
    flush for the waste solids?
3.  Was the reduced flush adequate for liquid
    wastes?
4.  Did the device provide an excessive
    supply of water for flushing purposes?
5.  Approximately how much of the time was
    the reduced flush used?
6.  Was use of the full flush inconvenient?
7.  With the toilet device installed, have you
    found it necessary to clean the toilet
    bowl more frequently?
8.  Was the device easily installed?
9.  Did the device function satisfactorily?
    Was the maintenance required minimum?
   10
   11
    Would you recommend this toilet device
    to others?
   12.  Do you feel the retail price is too high?  _0
NUMBER OP
RESPONSES
Yes
Aver
10
12.
10
A
JL
d
_6
_p_
52
_o
on
\J \sL
_0_
_6_
A
JL
_6
i? 0
No
3
. 10$
2
_0
__2_
_0
_0
0
JL
i
_6
_6
jO
0
_0
-2
6
             Econo-Plush:
             Sink-Bob:
             Saveit:
                             !>13.95   A
                             !> 3.00 - $4.00
                               6.99
                               99

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                                                NUMBER OF
                                                RESPONSES
                                                  Yes   No
D.  RECYCLED WATER SYSTEM FOR TOILET FLUSHING
    1.  Did you find the recycled water system
        complex to use?                           JO     6
    2.  Did you find the system unmanageable?      0     6
    3.  Did the system provide an adequate water
        supply for flushing purposes?              6     0
    4.  Did the system perform satisfactorily?     6     0
    5.  Was the maintenance required minimum?      3     3
    6.  Did the system require a minimum of
        surveillance?                              4     2
    7.  Did you find the reuse of treated wash
        water for toilet flushing objectionable?   1     5
    8.  Were there additional cleaning require-
        ments for the toilet bowl with this
        system?                                    6     0
    9.  Were there any problems because of:
        a) odors generated?                        2     4
        b) appearance or color of the water?       1     ^
        c) excessive discoloration or staining
           of the toilet trap?                     6     0
        d) excessive foaming?                      0     6
        e) the requirement and use of disin~
           fectants?                               3     3
        f) a concern for a possible health
           hazard?                                 2     4
        g) the design of the system?              _1_
   10.  Would you recommend this system to others ?__4

E.  RECYCLED WATER USED FOR LAWN OR GARDEN WATERING
    1.  Did the use of treated laundry/bath water
        for lawn or garden use have any obvious
        adverse effect on your lawn or soil?       0
    2.  Did it have any beneficial effect over
        conventional lawn watering?                0
                              100

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RECYC1
                                                NUMBER OP
                                                RESPONSES

                                                  Yes   No
             WATER USED FOR LAWN OR GARDEN WATERING (Cont'd)
3.  Would you recommend use of this system to
    others ?                                    2

4.  Did you feel a concern for any possible
    health hazard?                             2

5.  Did the use of the system have an adverse
    effect on the operation of the sprinkler
    system?                                    0

*Homeowner #7 felt that manually operated lawn
watering reuse was impractical for his situation,
He did indicate approval of an automatically
operated sprinkler set-up.
                                                         2*
                                                         0
F.  GENERAL
    1.
    3.
    Did you realize a cost savings during the test
    program through the use of water saving devices
    or a recycling system by:
                                         Yes
                                              No way to
                                              evaluate
        a
        b
        c
       decreased water bill?
       decreased electric bill?
       decreased fuel bill?
    If the home was served by a sep-
    tic tank or leach field, were
    there any noticeable changes in
    service requirements for these
    facilities during the study?      6    £

    If yes, explain:  See Section
    VIII for explanations.

    Do you plan to include in your home
    any of the following devices when this
    test is completed?
    a) restrictive flow shower-head device?
    b) toilet flush water saving device?
    c) shallow-trap toilet?
                                                  Yes  No
                              101

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                                                NUMBER OP
P.  GENERAL (Cont'd)                            RESPONSES

                                                  Yes   No

    4.  If recycle systems were commercially
        available, would you:

        a) reuse laundry /bath water for toilet
           flushing?                              _4    _2

        b) reuse laundry/bath water for lawn
           or garden watering?                     2     4

    5.  If answers to 4(a) and/or 4(b) were yes,
        how much would you be willing to spend?
        No more than:

        $200 1  . $300  2 . $400  2 , $500  2 . $600	0__

    6.  Would you recommend homeowner's partici-
        pation in other test programs such as
        this?

    7.  Other comments and suggestions concern-
        ing this test program would be appreciated.


G.  IDENTIFICATION

    Name
    Age	  Sex	
    Relation to homeowner
                               102

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                         *      TECHNICAL REPORT DATA
                         (Please read Instructions on the reverse before completing)
 EPA-670/2-74-071
 4. TITLE AND SUBTITLE

 DEMONSTRATION OF WASTE FLOW REDUCTION
 FROM HOUSEHOLDS
                                                       3. RECIPIENT'S ACCESSION-NO.
                                                     5. REPORT DATE
                                                       Sept.  1974;  Date of Issue
                                                     6. PERFORMING ORGANIZATION CODE
 7. AU
 Sheldon Cohen  and Harold Wallman
                                                     8. PERFORMING ORGANIZATION REPORT NO

                                                       U440-74-057
 9, PERF
      /IING ORGANIZATION NAME AND ADDRESS
Materials and Environmental Engineering,
Electric Boat Division
General Dynamics Corporation
Groton, Connecticut   06340
                                                       10. PROGRAM ELEMENT NO. 1BB033 *

                                                        ROAP 21 ASW; Task 010A
                                                       11. CONTRACT/GRANT NO.

                                                        68-01-0041
 12. SPONSORING AGENCY NAME AND ADDRESS
 National  Environmental Research  Center
 Office of Research & Development
 U.S. Environmental Protection Agency
 Cincinnati, Ohio  45268
                                                      13. TYPE OF REPORT AND PERIOD COVERED
                                                       Final
                                                     14. SPONSORING AGENCY CODE
 15. SUPPLEMENTARY NOTES
 16. ABSTRACT                        	—	——	
      A two-year demonstration  program was conducted to evaluate water savings,
 costs, performance and acceptability of various water-saving devices.  Reduced
 flow toilets  and flow limiting shower heads were installed in eight single-
 family dwellings.  In three of the homes bath and laundry  water was filtered,
 disinfected,  and reused for toilet flushing and/or lawn sprinkling.  The ex-
 perimental portion of the program ran from May 1971 to May 1973.    ;

      Water requirements for toilet flushing were substantially reduced in an
 economically  attractive and aesthetically acceptable manner.   Shallow trap and
 dual-flush toilets resulted in average decreases in toilet water usage of 25%
 and 23%, respectively.  Flow restricting shower heads proved to be relatively
 ineffective,  however this result  may have been due to use  patterns unique to
 this study.

      Wash water recycle systems provided satisfactory operation throughout the
 test period.  The average savings for toilet flushing reuse ranged between 23%
 and 26% of total water usage.   The incorporation of lawn sprinkling as a
 supplemental  reuse mode further reduced waste flow from homes by 16% to 18%.
 For single-family dwellings, recycle systems could effect  marginal cost savings
 in high water and sewer use rate  areas.  They are definitely warranted when
 septic systems  with poor drainage (due to soil or topography) are encountered.
                             KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
                                         b.lDENTIFIERS/OPEN ENDED TERMS  C.  COSATI Field/Group
 *Water conservation, *Houses,
 *Water reclamation, Sewage treatment,
 Filtration, Disinfection, Cost Analysis
                                           *Sewage flow reduction
                                           *Home water reuse,
                                           Plumbing fixtures,
                                           Showers, Toilets,
                                           Lawn watering
                                                                       13 B
 8. DISTRIBUTION STATEMENT

 Release to public
                                         19. SECURITY CLASS (ThisReport)'
                                           UNCLASSIFIED
21. NO. OF PAGES

    111
                                         20. SECURITY CLASS (This page)
                                           UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
                                       103
                                               U.S. GOVERNMENT PRINTING OFFICE: 197A-657-585/5306 Region No. 5-M

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