Flow
Reduction
Methods,
Analysis Procedures,
Examples
COST EFFECTIVENESS
-------
TECHNICAL REPORT DATA
(I'lt ait rcatl tmlnirnom on llif ' n rsc In/ore t tint fit unvl
1 REPORT NO
4 TITLE AND SUBTITLE
Flow Reduction - Methods, Analysis, Procedures,
Examples
7 AUTHOR(S)
9 PERFORMING ORGANIZATION NAME AND ADDRESS
Office of Water Program Operations
Facility Requirement Division
Washington, DC 20460
3 RECIfllENl S ACCESSION NO
at - -
'PORT DATF
March,
6 PERFORMING ORGAN I,? AT'ON CODE
8 PERFORMING ORGANIZATION REPORT NO
10 PROGRAMELfMENTNO
12 SPONSORING AGENCY NAME AND ADDRESS
Office of Water Program Operations
US Environmental Protection Agency
Washington, DC 20460
II CONTRACT/GRANT NO
13 TYPE Of 'TLPORT AND I'E RIOD COVL REO
Technical Report
14 SPONSOR NU"AGENCYcoot~
700/02
15 SUPPLEMENTARY NOTES
1C ABSTRACT
This report is a study of the effect of the Industrial Cost Exclusion (ICE) or
the construction grants program. This study and the report were directed by the
Congress in section 4 of a recent amendment to the Federal Water Pollution Control
Act (Public Law 96-483). The report reflects the full range of opinions expressed
to the Agency during the conduct of our study. Comments and data were provided
by water pollution control agencies of the several States, communities and
industries that will be affected by the industrial cost exclusion, interested
public and private interest groups and other parties.
, The impacts of ICE have been assessed from both the industrial and municipal
perspectives in order to objectively analyze the potential consequences. Further,
the report analyzes the impacts on rural communities and on industries in eco-
nomically distressed areas and areas with high unemployment; Specific communities
and projects are identified and each State is analyzed in terms of short-term
and long-term effects of ICE.
This report contains a factual analysis of the effect of the ICE as well as
a review of the impacts of a number of alternatives to the ICE requirements.
DESCRIPTORS
KEY WORDS AND DOCUMENT ANALYSIS
ll lOENTir IE RS/OPf N ENDED fCRMij
Water Conservation
Flow Reduction
I iiKI/dmup
18 DISTRIBUTION STATEMENT
19 SECURITY CLASS 11 Ins Kcport/
Unclassified
21 NO OF PAGES
20 SECURIT i- CLASS
22 P
( EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION is OBSOLETE
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Methods,
Analysis Procedures,
Examples
Project Officer: Myron Tiemens
Facility Requirements Division
Office of Water Program Operations
U.S. Environmental Protection Agency
Washington, D.C. 20460
March 1981
-------
Preface
Flow Reduction: Methods, Analysis
Procedures, Examples, is the first volume of a
three-volume series pertaining to wastewater flow
reduction analysis and program planning With
increasing numbers o< communities becoming
interested in the potential benefits of flow reduc-
tion and with the introduction of flow reduction
analysis requirements into the treatment facilities
Planning (Step 1) phase of EPA's Construction
Grants Program, a need was felt to provide
guidance on flow reduction analysis procedures
and in developing community programs Each
volume of this senes thus works toward the
ultimate objective of developing community flow
reduction programs that are practical, cost effec-
tive and able to be implemented
a Part I of this first volume provides back-
ground information on flow reduction.
including its role in facilities planning, its
relationship to other water and wastewater
programs, and case examples of
communities which have implemented pro-
grams Part n provides a step-by-step
methodology to serve as a guide in carrying
out the llow reduction analysis Descriptions of
various flow reduction measures are included
along with an assessment of their cost effec-
tiveness
Part HI, a separate volume, demonstrates the
flow reduction methodology by applying it to
two real world communities These
documented case studies not only clarify the
procedure but highlight the nature ol llow
reduction's costs and benefits
"Part IV is a package ol flow reduction public
information material designed to supplement
a community's llow reduction program This
package consists of general guidance in
developing a public information program,
examples ol specific techniques communities
have used, and sample material which can
be adapted for direct use in a community's
program
Through these three interrelated documents it
is hoped that community leaders and planners
will find the practical rationale and overall
guidance needed to consider the potential of
flow reduction in their particular settings
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Table of Contents
Prelace . i
List of Illustrations . , vll
List of Tables lx
Acknowledgments xi
Part I AN OVERVIEW OF WASTEWATER FLOW REDUCTION
AND USE OF THIS DOCUMENT 3
A What Is Flow Reduction? 3
B What Are the Potential Benefits of a Flow Reduction Program? 4
C What Have Other Communities Achieved? 5
D Motivations for Flow Reduction 7
E The Legal Basis of Flow Reduction 7
F What Are the Determinants of Wastewater Flow? , 8
G How Is "Flow Reduction Related to Other Programs? 9
1 Facilities Planning (Step 1) under the EPA Construction Grants Program 9
2 Infiltration/Inflow Analysis ' 9
3 Industrial Wastewater Flow Analysis . , . 11
4 Reuse . . 11
5 Recycling . . 11
6 Water Conservation ' 11
7 Energy Conservation , 11
H Who is Involved in Flow Reduction Planning and Program Implementation and Why? 11
I How Can This Document Assist Municipalities in Responding to the Regulations? 12
j Four Examples of Programs Other Communities Have Implemented .... ... 13
1 Oak Park, California . . .... 13
2 Elmhurst, Illinois . . . 13
3 Denver. Colorado . . .13
4 Washington Suburban Sanitary Commission . 14
K Key Steps in the How Reduction Analysis 14
Part II A GUIDE FOR FLOW REDUCTION ANALYSIS 17
A Is Flow Reduction Analysis Required? 21
1 Statement of Purpose 21
2 Data and Information Needs 21
3 What To Do ' 21
B Establish Wlthout-Flow-Reduction Condition 23
1 Statement of Purpose . 23
2 Data and Information Needs 23
3 What To Do . 24
4 Example 24
5 Major Observations 24
Preceding page blank
Ul
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C- 1 Develop First-Cut Flow Reduction Program
1 Statement of Purpose .
2 Data and Information Needs
a Categories of Flow Reduction Measures
1) Structural Methods
2) Economic Methods
3) Legal/Institutional Methods
4) Educational Methods
b Costs and Water/Energy Saving Consequences of Individual Measures
3 What To Do
a Synthesize a First-Cut Program
b Define a Supporting Public Information Program
c Address Implementation Issues and Develop an Implementation Plan
4 Examples
a Sample Programs
b Calculating Expected Reduction in Indoor Residential Water Use From
Implementation of a Flow Reduction Program A Hypothetical Case
5. Major Observations
D Determine Costs and Benefits of the Flow Reduction Program
1 Statement of Purpose
2 Monetary Benefits and Costs of the Flow Reduction Program . ,
a Monetary Costs ....
b Monetary Benefits
1 ) Cost Savings to the Wastewater Utility
2 ) Cost Savings to the Water Supply Utility
3 ) Cost Savings to Water Users
c Determination of Net Monetary Benefits
3 Nonmonetary Benefits and Costs of a Flow Reduction Program
4 Major Observations
E Have All Reasonable Alternatives Been Considered?
1 Statement of Pu rpose
2 Data and Information Needs
3 What To Do
4 Examples
a Program Modification Is Indicated
b A New Approach Is Indicated
5 Major Observations
F Conduct Public Participation Meeting
1 Statement of Purpose
2 Data and Information Needs
3 What To Do . ...
4 Example .
5 Major Observations
29
29
29
29
. . 29
32
33
33
33
34
34
35
35
36
36
37
38
43
43
43
43
43
43
46
48
49
49
50
53
53
53
53
53
53
53
53
55
55
55
56
56
56
Iv
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G Select a Flow Reduction Program . 59
1 Statement ol Purpose 59
2 Data and Information Needs 59
3 What To Do 59
4 Major Observations . 59
H Incorporate Flow Reduction Program Into Facilities Plan 63
1 Statement ol Purpose 63
2 Data and Information Needs 63
3 What To Do , , 63
4 Major Observations ' 63
References 65
Appendix A
Sections 8b, c, and d of the Cost-Effectiveness Guidelines for the Construction Grants Program 69
b Wasiewater flow estimates 69
c Flow reduction , 69
d Industrial flows 70
Appendix B
Detailed Descriptions of Selected Flow Reduction Measures 71
1 Water Saving Devices and Appliances ' 71
a Products for Installation in New Construction, Remodeling, and Replacement 71
1) Shower Heads . 71
2) Faucets . 72
3) Toilets 73
4) Home Appliances . 74
5) Pressure Reducers 74
b Installation of Flow Control and Water Saving Devices in Existing
Residences and Businesses (i e . Retrofitting) 75
1) Shower Retrofits 77
2) Faucet Retrofits 77
3) Toilet Retrofits . ' 79
4) Other Retrofitting 79
2 Types ol Water Pricing Structures 79
3 Building and Plumbing Code Changes « 81
a Excerpt from the Fairfax County (Virginia) Plumbing Code 82
b Authorization and Connection Requirements Issued by the Washington
Suburban Sanitary Commission 82
c Water Conservation Plumbing Code Recommendations of the
Plumbing Manufacturers Institute . 83
Appendix C
Relative Economic Benefit? of Selected Water Saving and Flow Control Devices 85
1 Relative Monetary Benefits of Flow Control Devices 85
a Major Assumptions 85
b Results of the Anolysis 86
2 Examples of Calculation Methods Used 87
3 Consideration ol Double Counting 87
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Appendix D
Water Conservation and Flow Reduction Bibliography
Selected References Organized by Subject 91
1 Water Conservation and Flow Reduction Measures 91
2 Case Studies . 91
3 Technical Background o( Wastewater Treatment Operations and Flow Reduction Ef Jects 91
4 Comprehensive Overviews 91
5 Annotated Bibliographies 92
6 EPA Construction Grants Program 92
7 Infiltration/Inflow Analysis 92
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List of Illustrations
figure I Potential Reductions in Water Use and Wastewater Flows Irom Indoor Water Conservation
Figure 2 Long-term Monetary Benefits to the Community Irom Water Conservation/Flow Reduction
Figure3 Results Irom Oak Park. California's Water Saving Program
Figure 4 Flow Reduction Analysis Within Facilities Planning
Figure 5 Who Participates in Flow Reduction Planning7
Figure 6 Flow Reduction Analysis
Figu re 7 Major Components of a Flow Reduction Program
Figure 8 Sample Diagram Showing Capacity Needs Versus
Time and Staging Requirements
for the Without-Flow-Reduction Condition
Figure 9 Possible Sizing/Staging Changes as a Result of Flow Reduction Program
Figure 10 With- and Without-Flow-Reduction Conditions lor Hypothetical Wastewater Facility
Figu re 11 Sizing and Staging of Water Utility Treatment Facility
With and Without Flow Reduction Measures
FiaureBl Low Flow Shower HeadsComparison to Conventional Models
Figure B-2 Typical Flush Valve
Figure B-3 Shallow Trap Toilet
Figure B-4 Typical Pressure Reducing Valve
Figure B-5 Typical Shower Retrofit Devices
Figure B-6 Shower Retrofit DevicesComparison to Conventional Shower Heads
Figure B-7 Toilet Retrofitting Techniques
Fiaure B-8 Four Water Pricing Structures
4
0
8
10
12
15
18
26
45
47
40
72
73
73
75
76
77
78
80
Vll
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List of Tables
Table I Cornerstones of Flow Reduction and This Document
Table 2 Indoor Residential Water Use and Potential for Water Savings with Conservation
Fable 3 Steps in Flow Reduction Analysis
Ta b'.e 4 Sample Data Sheet tor Water Use Projections
Table 5 Sample Data Sheet tor Wastewater Flow Projections
Table o Characteristics of Common Flow Reduction Measures
Table ? Ranges of Costs and Water/Energy Savings from Indoor Residential Conservation
Tab:? 8 Sample Flow Reduction Program lor Hypothetical Community
with Relatively Immediate Flow Reduction Goals
lab!e u Sample Flow Reduction Program for Hypothetical Community
with Relatively Long-Term, Aggressive Goals
Table 10 Effects of Program Elements on Residential Indoor Per Capita Water Use
for Hypothetical Community
Table 11 Expected Residential Water Savings from Flow Reduction Program Elements
lor Hypothetical Community
Table 12 Comparison of Indoor Residential Water Use With and Without Flow
Reduction Program for Hypothetical Community
Tnble 13 Scopeof Community-Wide Monetary Benefits and Costs
Ta ble 14 Assumptions Used to Develop Hypothetical Example of Cost Savings
to a Wastewater Treatment Facility
Table 15 Calculations (or Hypothetical Example of Cost Savings
to a Wastewater Treatment Facility
Table 16 Example of Calculation Procedure to Allow (or Energy Price Imlahon
Table 17 Determining Net Monetary Benefits to the Community
Table i 8 Example of a Qualitative Assessment to Nonmonetary Costs and Benefits
of a Flow Reduction Program
Ta ble 19 Organization of Data for Final Program Selection
Taole C-1 The Relative Economic Benefits from a Community Viewpoint
of Common Water Saving Devices and Appliances
Table C-2 Example Calculation (or Shower Head with Plastic Insert and Flow Varying with Pressure
lable C-3 Example Calculation for Faucet Aerator
Table C-4 Example Calculation for Toilet Dams
Table C-5 Example Calculation for Installing Pressure Reducing Valve in New Construction
Table C-6 Example Calculation for Clothes Washer
Table C- 7 Example'Calculation for Dishwasher
2
5
14
24
25
30
33
36
37
38
39
40
44
46
48
50
51
51
60
86
88
88
88
89
89
89
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Acknowledgments
Flow Reduction.- Methods, Analysis Pro-
cedures, Examples was prepared under the
direction of Myron Tiemens, Deputy Director of
EPA's Facility Requirements Division, and Barbara
Yeaman. Public Education Consultant to EPA. Both
provided comments and guidance which greatly
benefited this document
Contractor on this project was INTASA inc. of
Menlo Park, California. Nicolaos V Arvanitidis.
President of INTASA, supervised preparation of
this document and performed coordination with
EPA Day-to-day project management was the
responsibility o, Bill Betchart, research and writing
on the project was by Sandra Postel and Sally
Davenport as well as Mr Betchart Graphic design
and artwork preparation were the responsibility
of John Bird Advertising & Design of Palo Alto,
California The manuscript text was typeset at
LARC Computing, Inc of Los Altos, California
Finally, the INTASA team wishes to
acknowledge all those both inside and outside of
EPA who took the time to review and comment
on draft versions of this document
Preceding page blank
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Flow reduction can mean:
Thus document will show-
How to calculate the monetary costs
and benefits ol the flow reduction
program
What household monetary savings can
be achieved through difterent flow
reduction measures
Examples of communities that have
avoided economic tosses by
implementing common flow reduction
measures
!- 'ft&k
How a community can put together a
workable flow reduction package
How facilities planners can meet EPA's
flaw reduction analysts requirements
r.oTn«»rrton«!s Ol How Reduction And Thts Docutnsnl
Preceding page blank
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AN OVERVIEW OF
WASTEWATER FLOW REDUCTION
AND USE OF THIS DOCUMENT
When the one-million-gallon-per-doy (mgd)
wastewater treatment plant serving Gettysburg,
Pennsylvania became overloaded in 1973, a con-
struction moratorium went into effect which
threatened to cause substantial economic losses
to the area As a direct result of a concerted effort
to reduce wastewaler flows, the ban was partially
lifted in 1976. saving an estimated $29 million to
the regional economy (Sharpe, 1978)
Increasing numbers of communities across
the nation are turning to flow reduction programs
to deal with municipal wastewaler management
problems While many of these programs have
been undertaken in direct response to existing or
imminent crisis situations, the potential to realize
long-term benefits is also being recognized
Moreover, flow reduction must now be a
direct concern of v/astewater treatment facilities
planners With the exception of those areas with
(1) populations under 1O.OOO, Q average daily
base (lows less than 7O gallons per capita per
day (gpcd), or (3) an approved flow reduction
program, all municipalities or districts seeking
Federal funds for construction of wastewater treat-
ment plants are now required by the US
Environmental Protection Agency (EPA) to
examine flow reduction alternatives in their facil-
ities planning
Carrying out the flow reduction analysis
required by EPA in no way interrupts the other
aspects of facilities planning Much of the infor-
mation and data needed for the analysis is also
essential to the overall facilities plan. The plan-
ning process and flow reduction analysis can be
carried out simultaneously, with the recom-
mended flow reduction program being
incorporated into the final facilities plan
This document highlights the nature and po-
tential eflects of a flow reduction program and in-
forms local officials about benefits their commun-
ities can receive from implementing such a pro-
gram In addition. Part II presents a procedure by
which planners can evaluate and compare the
effects of alternative flow reduction programs on
the community's wastewater utility, water supply
utility, and individual households Table 1 high-
lights potential benefits of flow reduction to the
community, and the usefulness of methods, anal-
ysis procedures, and examples provided in this
document in realizing that potential
A. What Is Flow Reduction?
As its name implies, generic flow reduction is
oriented toward reducing (or at least slowing the
growth of) the quantity of wastewater flowing into
a municipa'ity's wastewater treatment plant
Within wastewaler facilities planning under the
Clean Water Act. "flow reduction analysis" has a
more Specific meaning
It is directed toward reducing wastewater
flows by implementing broadly applicable water
conservation techniques in residential, commer-
cial, public and small-scale industrial settings
Quantities of wastewater flowing into treatment
works are significantly affected by these commu
nity-wide water uses Thus etlorts to reduce water
use often simultaneously serve to reduce waste-
water flows, and flow reduction is closely tied to
water conservation Although the two types of
programs differ (for example, water conservation
efforts to reduce water use lor landscape
irrigation will have little effect on the quantity of
wastewater flow), water conservation or water
saving measures are the core of any flow
reduction program
Two other types of analytical efforts to reduce
wcstewater flows are separate from but
supplementary to. the flow reduction analysis
addressed in this document
Infiltration/inflow analysis, which attempts to
reduce the amounts of groundwater and rain
watei that find their way into the wastewater
system
Industrial wastewater flow analysis, which
attempts to reduce wastewater flow from
specific industrial users (i e. those with flows
greater than 25.OOO gallons per day (gpd))
by analyzing their process configurations to
achieve more eflicient water use and
reduced waste loadings
Though not further emphasized herein, both
infiltration/inflow and industrial flows can be
major contributors to the total wastewaler flow
and thus of significance in sizing wastewater
treatment works
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'$m
Figure 1 Potential Reductions In Water Use And Wastewaler Hows From Indoor Water Conservation
B. What are the Potential Benefits
of a Flow Reduction Program?
An effective flow reduction program can
provide immediate and long-term benefits »o
both the community and the individual consum-
er The immediate benefit of averting a pending
water supply or wastewater treatment crisis is one
Irecruently mentioned example. However, lasting
program-induced reductions in water use and
wqstewater flows can produce significant long-
term benefits. Where such long-term benefits can
.be identified, short-term crises need not be
present to motivate and justify a flow reduction
program
Long-term monetary benefits to the com-
munity can result from being able to postpone, or
eliminate, expansion of an existing treatment
facility or construction of a new facility Or, a flow
reduction program may enable a community to
plan for and construct a smaller treatment plant
than would have been possible without flow
reduction efforts In these situations, there can be
benefits in the form of reduced capital and
interest expenditures as well as operation and
maintenance costs. As discussed more fully in
Part n. the realization and magnitude of these cost
savings will depend upon the community's
specific wastewater and treatment-facility
characteristics.
Water conservation measures implemented
as part of a flow reduction program will produce
similar long-term water supply cost savings by
reducing the scale or postponing the expansion
of different aspects of the water supply operation
On the other hand the short-term effect of
reducing a community's water use may be to
decrease revenues without substantially altering
costs, since most of the utility's costs are fixed costs
tied to available capacity Although this revenue
eflect can be a major concern, the problem is by
no means insurmountable Revenues lost through
conservation may be ottset by a normal increase
in the number of customers served unused
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Indoor Water Use
Tbilet Hushing
Bathing
Lavatory sink
Laundry & dishes
Drinking & cooking
Total
Total
Indoor Use
(percent)
40
30
5
20
5
100
a Based on data in US EPA. 1979
b Assumes use o! toilet dams plastic shower
c Gallons per capita per day
Without
Conservation"
(gpcd)'
25
20
3
13
4
65
head inserts and water conserving
With
Conservation'
(gpcdy
175
16
3
95
4
50
dishwashers and washing
Reduction
(percent)
30
21
-
27
-
23
machines
Table 2 Indoor Residential Water Dse and Potential For Water Savings With Conservation
capacity thereby remaining unchanged Lost
revenues may also be recovered through a rate
inciease which will still be likely to result in a
lower waler bill to the average, conserving resi-
dential user Or. a flow reduction program can
be implemented gradually so that no immediate
reduction in revenues occurs The manner in
which the problem is tackled will depend upon
the particular community
Individual water users within the community
will also benefit directly from a flow reduction
program's effects on capacity The lower fixed
costs associated with constructing and operating
a smaller facility, or delaying facility expansioa
will translate over the long term into lower (or
smaller increases ir.) water and wastewater bills
for the water user who ultimately must pay the
cost of these services In addition, a reduction in
water use will mean a saving in costs for energy
used to heal water
Table 2 provides figures on an average
household's indoor water use and potential water
savings with selected conservation/flow reduc-
tion measures Figure 1 pictonally displays the
magnitude of these savings and Figure 2 portrays
what these savings can mean to the community
- both to the water and wastewater utilities and
to individual water users
An array of nonmonetary benefits may also
accrue to the community as a result of flow
reduction and associated water conservation
efforts Clearly, these benefits will vary greatly
depending upon the particular circumstances of
the community but may include
B Enhanced fish and wildlife, recreatioa and
aesthetic benefits
e> Increased number of services that can be
supplied from existing facilities with the
associated land-use and socioeconomic
advantages
Increased groundwater reserves
Avoidance of an imminent water supply or
wastewater treatment cnsis
Provision of the additional safety value of no
longer operating at the margin of available
water supply
C. What Have Other Communities
Achieved?
A drought-inspired conservation effort
undertaken by the East Bay Municipal Utility
District serving Oakland and Berkeley,
California has resulted in long-term post
drought reductions of about 15 percent in
water use and 1O percent in dry weather
wastewater flows During the 1977 drought.
wastewater flows were reduced by 28 per
cent (Vossbnnk, 198O)
Sprtngettsbury Township, Pennsylvania
succeeded in reducing average wastewater
flows by 25 mgd, allowing for termination of
a construction moratorium put into effect
when its 8 mgd wasiswater treatment plant
became overloaded As a result of infiltra
tion/inflow and flow reduction programs, the
cost of operating and maintaining the waste-
water facility has decreased by S18.OOO
annually at the same time thai iew
connections have led to increases in the
utility's revenues (Sharpe, 1978)
An overloaded wastewater treatment plant
and predicted future water shortages led the
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Indoor voter use
Bathing
Toilet
Laundry & dishes
Drinking & cooking
Lavatory sink
can be reduced by 23%
with conservation
lower water heating
bills for consumers
delayed and smaller
facility expansions and
long-term reduced costs for
water and wastewater facilities
Figure 2 Lonfl-Term Monetary Benefits 1b The Community From Water Conservation/now Seduction
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community ol Elmhurst Illinois to implement
o water conservation program targeted at
reducing wastewater flows by 8 to 1O percent
As a result ol the program. Elmhurst was able
to cancel construction ol a S4OO.OOO deep
well and to remove other deep wells and
storage facilities from use (Deline, 1978) A
comparison ol an average of the three years
prior to the program with an average of the
three years after the program indicates that
water use in terms ol average daily base flow
has decreased by 9 percent while peak-day
Hows have decreased by 14 percent (Fultoa
198O)
D A mass retrofit program in Oak Park,
California during the 1976-1977 drought
helped reduce total water deliveries by as
much as 48 percent and wastewater flows by
as much as 31 percent (California Department
ol Water Resources (DWR), March 1978) An
analysis of the long-term effects of the pro-
gram indicates that dry weather wastewater
flows have decreased by about 25 percent
since the retrofit program compared to the 17
months prior to. the program When data
from the months with high infiltration are
included, an 18 percent reduction in waste-
water flows is indicated (California DWR.
September, 1979) Figure 3 displays the
magnitude of these reductions
° A "Pilot Water Conservation Program"
comprising six areas (including Oak Park)
in California produced annual energy and
water savings estimated to be over $15
million. The annualized cost of the state and
local program was approximately $317,594
Moreover, survey results from four of the areas
indicated strong public acceptance (in the
range of 85 to 9O percent) ol the water saving
devices installed (Calilornia DWR, October
1978)
It is important to recognize that while the
ultimate goals o' flow reduction programs are
quite similar, the means ol achieving these goals
vary greatly. A flow reduction program can
consist of a variety ol very different flow reduction
measures, packaged so as to meet a
community's specific needs, budget, and
opportunities, and to respond to its particular
socioeconomic. political and environmental
setting Thus throughout this document, an
emphasis is placed on alternatives
D. Motivations lor Flow Reduction
In addition to the potential monetary and
nonmonetary community benefits already
discussed, an important motivating factor for How
reduction is that it will enable a limited amount
of Federal funds to go further in meeting water
quality goals As ol January 1978. EPA estimated
that wastewater facilities needed lor the year
2OOO (excluding stormwater control) would
require funds totaling S1O6 billion ol which 75 per
cent, or $79 5 billion, would be Federal dollars
(January 1978 dollars) With annual Federal
appropriations of $4 2 billion in Fiscal Year 1979
toward this 75 percent Federal share - and
without considering inflation - it would take 19
years to satisfy these needs Even li inflation were
only 5.5 percent per year, the year 2OOO needs
would never be met. even by appropriating $4 2
billion per year forever (U S EPA. 1979)
Federal construction grants appropriations in
Fiscal Year 198O were $34 billion and the budget
request lor Fiscal Year 1981 was $37 billion
Considering that these amounts are substantially
less than earlier levels 'and that inflation has
been much greater than 55 percent per year, it
will be extremely difficult to catch up with our
treatment facility needs Flow reduction is an
important component ol the light to control our
ever-expanding wastewater treatment needs and
an opportunity lor municipalities to demonstrate
success in this struggle
£. The Legal Basis ol Flow
Reduction
EPA's requirement that flow reduction be
considered in wastewater treatment facilities
planning stems from several policy initiatives in
both the executive and legislative branches ol
the federal government
President Carter, in his June 6,1978 Water
Policy Message, resolved to make water con-
servation a national priority Along with
requiring tnat water conservation be added
to the Water Resources Council's "Principles
and Standards," the President issued a
specific directive to the EPA and Departments
of Agriculture, Commerce, and Housing and
Urban Development to make "appropriate
community water conservation measures a
condition ol water supply and wastewater
. treatment grant and loan programs
Congress, with passage ol the 1977 Clean
Water Act, altered EPA's wastewater Construe
tion Grants Program to require that the
approvable amount of reserve capacity tor
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Water use Increase
(after drought)
Nole Percenlna? changes Irom |97/> to ]977 and 1976 to I'78 based on compnnson ot syven months (June-December).
Source California DWR March l°7« and September 1°7O.
Figure 3 Results From Oak Park. California's Water Soring Program
trealment facilities take into account "efforts
to reduce total How ol sewage and
unnecessary waler consumption."
EPA. acting under this new authority, included
in its cost-effectiveness guidelines lor the Con-
struction Grants Program the requirement thai:
"The cost-effectiveness analysis for each facil-
ity planning area shall include an evaluation
ol the costs, cost savings, and effects ol flow
reduction measures unless the existing ADBF
(average daily base flow) from the area is
less than 7O gpcd or the current population
of the applicant municipality is under
1O.OOO. or the Regional Administrator
exempts the area for having an effective.
existing flow reduction program." Thus, all
grant applicants not exempt under these
conditions must consider flow reduction pro-
grams within their facilities planning and
must include such a program if it is found to
be cost-effective and implementable (See
Appendix A for full text of Section 8c of EPA's
Cost-Eflectiveness Guidelines.)
F. What Axe the Determinants of
Waste-water Flow?
Water use is one main determinant
influencing wastewater flow Knowledge about
expected future water use and the patterns of
such use is essential to predicting and planning
lor future wastewater flows Specific factors
influencing future water use and. secondarily.
wastewater flows include:
Population - including number, growth rate,
distribution and density of water users.
Per capita use in various sectors ol the com-
munity - residential, commercial, industrial.
public.
Per capita use within categories ol certain
sectors - lor example, indoor versus outdoor
residential use and breakdown ol indoor use
into activities such as bathing, and toilet
flushing
Specifically identified industrial flows (under
Section 8d ol Cost-Eflectiveness Guidelines)
-------
o Limitations on the quantity and quality ol
water supply available
a Relative energy and capital costs associated
with storing, treating and distributing water
supplies
In addition to these water use characteristics.
the quantity of wastewater (low may be signif-
icantly affected by the amount ol rain water or
groundwater entering sewer pipes through leaks
(infiltration) and by water entering sewers via
roof downspouts and patio drains connected to
the sewer lines (inflow)
G. How is "Flow Reduction"
Related to Other Programs?
As implied before in this discussion a variety
of (actors affect wastewater (lows The following
subsections provide more detail on the scope of
[low reduction analysis in the context of facilities
planning under the Clean Water Act and its
relationship to other programs
1. Facilities Planning (Step 1) under the
EPA Construction Grants Program
Flow reduction analysis is an integral part of
facilities planning and is required in each Step 1
project unless the explicit conditions (or exemp-
tion are met (see Appendix A) It focuses on that
portion ol facilities planning which estimates the
expected magnitude of wastewater flow over
time - these estimates will be used in determining
the size and staging ol a facility and thus the size
of the immediate construction project It assumes
that the facilities planners have already
developed a "preliminary estimate" of expected
wastewater (lows (in accordance with most
provisions o( the Cost-Effectiveness Guidelines
Sections 8a. b and d) This allows facilities plan-
ning to continue while three detailed tasks are
performed (in accordance with the remaining
provisions of Sections 8a. b, c and d) to refine
Ihese flow projections into "final estimates" The
more detailed tasks are
o Flow reduction analysis
o Infiltration/inflow analysis
n Industrial wastewater (low analysis
These tasks are to determine whether there are
cost advantages in spending money to reduce
flows rather than to provide the larger facility
capacities to transport and treat them Figure 4
shows how flow reduction analysis relates to the
other tasks performed in facilities planning
2. Infiltration/Inflow Analysis
Step 1 facilities planning is required to
demonstrate the nonexistence or possible
existence of excessive infiltration/inflow (I/I)
within the wastewater collection system InLltra
'tion or inflow is deemed nonexcessive when it
costs less to collect and treat the extra water than
it would cost to eliminate it by rehabilitating the
collection system More specific requirements
and background regarding I/I analysis are
provided in several program documents (see the
bibliography in Appendix D)
Infiltration/inflow analysis is a separate facil-
ities planning activity, parallel to How reduction
analysis and onented toward developing (inal
estimates ol future wastewater Hows Its
interrelationship with (low reduction analysis is
characterized by the following points
Inliltralion/inflow analysis may have a much
larger ellect on the final capacity o( the treat
ment works than (low reduction analysis,
depending on local circumstances Indication
and inllow can increase the peak daily flow
through a wastewater treatment plant by a
factor ol live or even ten over average dry-
weather base (lows (Holland, 198O) Cost-
effective sewer system rehabilitation has
reduced these extraneous Hows by up to 3O
percent (Conklin and Lewis, 198O and Peil
and Diehl, 1978) Thus in I/I analysis facilities
planners are considering actions that may
reduce peak daily Hows by amounts
equivalent to several hundred percent of the
average dry-weather base (low It should be
noted however, that the costs involved in
reducing I/I are generally much greater than
costs associated with (low reduction
Reducing I/I may, in many cases, not be cost
effective
The "nonexcessive I/I", remaining after cost-
effective sewer system rehabilitation, can
detract from accomplishments under a (low
reduction program, especially if one
considers only their relative eflects on treat-
ment works capacity For example, a (low
reduction program might achieve a 1O per-
cent reduction in dry-weather base flows
through decreased and more efficient water
use If the "nonexcessive I/I" were to point
toward a treatment works hydraulic capacity
equivalent to live times the unreduced aver-
age dry-weather base (low, the "1O percent
(low reduction" (rom water conservation
activities would result in only a 2 percent
reduction in treatment works hydraulic
capacity
-------
Document
Facilities Plan
(including size
adjustments)
Assess
Current
and Future
Situation
Analysis of
Alternative
Treatment Works
Configurations
Select
Facilities
/oproach
Data and
Information
Transfer
Public Participation
Seduction Analysis
Refined
Row
Proiections
Industrial Flow Analysis
Infiltration/Inflow Analysis
Review
Approval.
Award of
Step 2
Figure 4 Flow Seduction Analysis Within Facilities Planning
-------
3. Industrial Wastewater Flow Analysis
In developing wastewater flow estimates,
planners may make specific allowances for
present (lows from industries now served, future
additional (lows from these or other specific
industries, and additional unplanned flows from
these or other unidentified industries (see Cost-
Effectiveness Analysis Guidelines. Sections 8b and
d) In the cases of present industrial flows and
specifically identified future increases in flow.
Section 8d requires that these flows "shall be
carefully reviewed and means of reducing them
shall be considered" This requirement is met by a
special "Industrial Wastewater Flow Analysis." the
third effort parallel to I/I analysis and flow reduc-
tion analysis and oriented toward final estimates
of wastewater flows
Industrial wastewater flow analysis focuses on
refining estimates of specific future industrial
needs lor capacity in the municipal wastewater
treatment works and on identifying and
implementing specific opportunities lor industrial
users to decrease their process-related discharges
to the wastewaler system This effort is closely
related to several other industrial topics within the
Construction Grants Program including
pretreatment. user charges and industrial cost
recovery
4 Reuse
Relative to the Construction Grants Program.
reuse means use of trealed effluent from a waste-
water facility lor some purpose such as
landscape or agricultural irrigation or industrial
cooling or processing This concern with use of
treated wastewater does not affect the quantity of
wastewater inflow into the facility Thus reuse is
viewed to be a separate topic, unrelated to flow
reduction EPA has recently published a separate
document (Camp Dresser and McKee. 198O)
which provides "Guidelines for Water Reuse"
5 Recycling
A water user such as an industry could
choose to recycle some of the water it uses.
thereby reducing the total quantity of water
supply needed and wastewaler discharged If
that industry's wastewaler goes to the municipal
treatment facility, such recycling will have a
direct impact on the amount of wastewater
inflow
Recycling is particularly relevant to industries
and thus it would be considered in "Industrial
Wastewater Flow Analysis" under Section 8d
Since other users may also recycle, recycling is
used in this handbook as an example of a
specific, though somewhat exotic, flow reduction
measure which could be analyzed in response to
Section 6c
6. Water Conservation
Flow reduction measures implemented in
response to Section 8c are intended to reduce
both water ucsd and wastewater discharged to
the sewers Thus ilow reduction measures
constitute a subset of water conservation mea
sures The difference is one of scope flow reauc
tion analysis focuses primarily on water conser
vation measures to reduce quantities of waste
water flowing into a treatment facility while
water conservation analysis encompasses all
measures to reduce water use Thus measures to
reduce water used for outside irrigation are not
within the scope of flow reduction analysis, they
would be a concern lor water conservation plan-
ning. However, if a community so desires, it can
do comprehensive water conservation analysis in
conjunction with its flow reduction analysis - such
an effort is considered grant eligible by EPA In
any case, the success of flow reduction efforts is
dependent upon close coordination with water
supply authorities and any ongoing water conser
vation program
7. Energy Conservation
Wastewater flow reduction also promotes
energy conservation The principal mechanisms
for energy savings with less water use are
Less energy needed to heal hot water if less
hot water is used
Less energy needed lor water supply
pumping and treatment
Less energy needed for wastewater pumping
and treatment
Because as much as hall of the economic
benefits of water conservation or flow reduction is
due to energy savings, especially from less use of
hot wafer, it is important to key in on energy
benefits in flow reduction analysis It is also
important to coordinate flow reduction efforts with
any on-going energy conservation efforts so that
appropriate combinations of energy and water
conservation are achieved
H. Who is Involved in Flow
Reduction Planning and
Program Implementation
cmd Why?
From the planning through implementation
stages of a flow reduction program, various
individuals, groups and entities assume important
-------
Community
Leaders
Facilities
Planners/
Consultants/
Advisors
Water and
Wastawater
Utilities
Directors of
Belated
Prooronxs
EPA/State
Project
Reviewers
Figure 5 Wno Participates In Flow Beductlon Planning7
roles Vital to the success of any How reduction
program is thai it be developed and implement
ed with full consideration ol and lull cooperation
Irom all parties concerned The number of parties
involved and the nature and extent ol then
involvement will vary with each particular com-
munity's circumstances but. as indicated in Figure
5, will most often include
n Community leaders They are the primary
decision makers in selecting a program
Their support tor the program and the
associated implementation and public infor-
mation effort is vital to program success
a The public This group is comprised ol
individuals and groups in the affected plan
ning area They can contribute to flow reduc
lion planning by providing input and support
during the planning process, and by being
receptive to. or assisting in. the public inlor
ma^'on campaign They also assume
primary roles in program implementation by
supporting and using those measures
comprising the program \
a Water and wastewater utilities. They provide
the data essential to the analysis and will be
primary agents of program development and
implementation Obtaining cooperation from
the water supply utility early in the process is
vital since the program will directly affect the
utihty and must be one which it can support
a Directors of related programs Those
carrying out water conservation, energy
servation infiltration/inflow and other pro
grams related to How reduction can be useful
sources of information Coordination with
related programs can help avoid duplication
ol efforts and promote overall program
efficiency
Facilities planners/consultants/advisors
They are responsible for developing the How
reduction program and incorporating its
objectives into the facilities plan
EPA/state project reviewers These
professionals can provide input into
programmatic aspects ol the planning
process They will also review the facilities
plans which document results of the flow
reduction analyses
I. How Can this Document Assist
Municipalities in Responding
to the Regulations?
In its cost-ettectiveness guidelines, EPA outlines
the key components of a (low reduction analysis
and cites specific measures to be considered in
developing a flow reduction program To help
municipal planners both meet the requirements
and develop a program of potential benefit to
their communities, this document does the
-------
following
a Outlines a step by-step process which
municipal planners can follow in developing
and evaluating alternative (low reduction
programs
a Identifies and describes typical flow reduction
measures and devices
o Provides inlormation on the costs and cost
savings to communities utilizing How reduc-
tion measures
o Provides generic models and sample
calculations which a planner can follow in
performing the required cost and cost savings
analyses of alternative programs
o Develops a framework to guide selection of a
final (low reduction plan
o Provides references where more information
about flow reduction measures and programs
can be obtained
J. Four Examples of Programs
Other Communities Have
Implemented
1. Oak Park, California
A relatively simple, small community pro
gram was implemented in Oak Park during the
1976-1977 drought A community consisting of 762
relatively new, single-family homes, Oak Park
was one of six areas selected for a Pilot Water
Conservation Program conducted by the
California Department of Water Resources Key
aspects of the program include (California DWR
March 1978)
a Program Components Free distribution and
professional installation of water saving toilet
and shower devices, a public information
piogram
o Program Costs
Retrofit Devices S 2.5OO
Informational Material and
Postage 2OO
Installation 7.2OO
Project Coordination and
Premstallation Preparation. Public
Relations and Inlormation 7.QQO
Total
S17.8OO
e Significant Findings
- Annual net benefit per household = $1683
- Estimated annual savings in local system
water and oil costs = S16.9OO
- Equivalent annual direct program cost
(amortized over 5 years at 6 percent interest
rate) = 54225
- Of those persons contacted. 914 percent
participated, 26 peicent could not be
contacted
- Retrofit devices were installed in 886 per
cent of toilets and 759 percent of showers
- Total monthly waler deliveries decreased
by as much as 31 percent as compared to the
same month in 1976
2 Elmhuist, Illinois.
Located 15 miles west of Chicago Elmhurst
is primarily a residential community o!
approximately 45.OOO which also supports a
major hospital, a private college and an indus
trial development Elmhurst. which owns and
operates its own water supply and wastewater
treatment systems, implemented a moderately
complex, moderately costly program (Fulton. 1978)
Program Components public information pro
gram, rate changes to encourage conser
valion. plumbing code amendments
requiring water-efficient appliances control of
outdoor water use. free distribution of toilet
tank dams, orifice reducers for shower heads.
and dye tablets lor leak detection
Program Cost approximately S45.OOO or $1
per capita
Significant Findings preliminary results
indicated a decrease in peak day water
consumption of 3O percent in 1977 compared
to 1976 The community was able to cancel
construction 01 a S4OO.OOO peaking well
3 Denvei, Colorado
Serving a city resident population of
535.OOO and a surrounding resident population of
375.OOO. the Denver Water Department undertook
a water conservation program primarily
consisting of public information and education
Key aspects include (Metcall & Eddy. Inc. 1976)
Program Components leaflets containing
water conservation tips, radio jingles and spot
announcements, animated color films, slide
show questionnaire to survey public attitudes
continued use of water news publication
mailed with water bills
Program Cost, estimated cost lor 1973-1975 is
S5O.OOO with an additional $35.OOO lor
production of color film
Significant Findings the public inlormation
program received a relatively high response
rate on the questionnaire Actual eBects of
the conservation eflort are unclear Total
13
-------
water use in 1973 was 11 percent lower than in
1972. but 1974 use rose to 1972 levels The lust 9
months of 1975 indicated a 9 percent reduc
lion from 1974 use It was reported t.iat 1974
was a warmer than average year, possibly
accounting lor the increase Achieving a
definitive assessment cl results in Denver is
further complicated by the fact that older
areas of the city are unmetered
4. Washington Suburban Sanitary
Commission.
The Washington Suburban Sanitary
Commission (WSSC) is an independent bi-county
agency providing water and sewer services to
approximately 12 million Maryland residents It
initialed its relatively large-scale. and%
sophisticated Water Conservation/Wastewaler
Reduction/Customer Education Program to deal
with a shortage of sewer capacity, and potenual
shortage of water supplies, to help offset
increasing capital and operating expenses and
to respond to an apparent public desire for such
a program The program has served as a model
for oihers
o Program Components public information
including distribution of a water conservation
handbook, holding workshops, and creating
a 2O-mmute film, distribution of 3OO.OOO
toilet displacement "bottle kits" and leak
detection pills, free shower flow control
devices plumbing code changes requiring
water saving toilets and shower heads, and
pressure reducing valves in certain areas, a
water conservation device test project
covering 2.4OO homes, and, most recently,
institution of a conservation-oriented rate
structure
a Program Cost over S5OO.OOO was spent on
the program between late 1971 and July 1975.
equivalent to slightly over S2OO per customer
account (Grear, 1975)
a Significant Findings
- A net minimum savings of 54 mgd was
achieved in 1974 (as compared with 1972)
amounting to a -442 percent reduction in
overall flows Since this is a conservative
estimate, it is quite possible that WSSC
achieved its goal of a 5 percent reduction of
indoor water use and resulting wastewater
flows (WSSC. 1974)
- Results from the test project (involving retrofit
of toilets, shower heads and pressure
reducing valves) indicated an 18 to 2O per-
cent reduction in water consumption over a
one year period in single family residences
and a 12 percent reduction in apartment units
(Bishop, 1975)
- Preliminary indications, based on a limited
time period, are that implementing the
increasing rale structure has had an impact
on residential customers but has not caused
significant changes in commercial and
government water use (McGarry 1978)
K. Key Steps in the Flow
Reduction Analysis
Part II of this document is a guide to carrying
out a flow reduction analysis The methodology
developed in the guide consists of a sequence of
steps which incorporates suificient flexibility to
accomodate differing community circumstances
The steps of the flow reduction analysis are
portrayed in Figure 6 and briefly described in
Table 3
Is Flow Reduction Analysis Required? Examine exemp
lion cnlena and determine whether How reduction
analysis is recruired.
B Without-now-Reduction Condition Determine present
and proiected water use and waslewater How character-
istics without (low reduction to establish a base condition
C-l First-Cut Program. Evaluate available How reduction
measures and develop a first-cut community program
D Costs and Benefits Determine the lull range ol monetary
and nonmonetary costs and benelits ol the program
alternative A with program/without program comparison
is used in calculating monetary cost-savings
E Have All Seasonable Alternatives Been Considered''
Consider whether a better program may result Irom
modifying the lirst-cul program or developing an entirely
new program
C 2 Modify Program or Develop Alternatives II the response
to Step E is no loop back to Step C-2 and then proceed
through Step D to evaluate this new alternative When all
alternatives have been evaluated p .>ceed to Step F
F Public Participation Meeting Present the analysis findings
at a facilities planning public meeting or hearing Obtain
public input and make appropriate changes in alternative
programs and their evaluations
G Select a Flow Reduction Program Evaluate the alterna
lives according tc established selection criteria and select
a recommended program
H Incorporate Into Facilities Plan. Make appropriate
adiustments'm the facilities plan documenting the
recommended How reduction program and its impact on
wastewater Hows
"table 3 Steps In Flow Seduction Analysis
14
-------
Yes
Figure 6.
Flow Reduction
Analysis
-------
A GUIDE FOR
FLOW REDUCTION
ANALYSIS
The How reduction analysis approach
presenied here is meant to serve as a guide tor
facilities planners charged with responsibility tor
performing a flow reduction analysis during the
facilities planning (Step 1) phase of the Construc-
tion Grants process It represents one framework
that can be used to structure thinking about the
flow reduction measures a particular community
might choose to adopt It is designed to be
adaptable to individual community
characteristics (it is not to be taken as a rigid set
of directions for flow reduction planning) and to
be nondisruptive to other elements of the facilities
planning process The parallel relationship and
interconnections between the flow reduction
analysis and other tasks of facilities planning are
evident from Figure 4 (page 1O)
The methodology lor flow reduction analysis
developed herein consists ol a sequence ot steps
that can be followed both to meet the require-
ments ol Section 8c ol EPA's Cost-Effectiveness
Guidelines for Step 1 facilities planning, and to
establish the foundation lor a cost-effective and
irnplementable community-wide water sav-
ing/flow reduction program As such it is the first
phase ol an effort that will continue throughout
Step 2 (design) and Step 3 (construction) of the
Construction Grants process should the results ol
the analysis point toward the desirability of
instituting a How reduction program in a partic-
ular community Thus the "bottom line" ot flow
reduction analysis is a Flow Reduction Program
consisting ol three vital components As illustrated
in Figure 7, these components are
o A package ol structural and nonstructural
flow reduction measures lor reducing water
use and thus achieving reduction of waste-
water flows
a A plan lor inlorming the public about these
water saving/How reduction measures and
the benefits to the community and consumers
ot adopting them
a A plan for implementing both the water sav-
ing/flow reduction measures and the public
information effort, including interagency coor
dination agreements, budget and manpower
requirements, schedule, and the like
These program components are mutually
supporting and essential lor achieving immediate
and long-term water savings and the resultant
wastewatei flow reductions in the context ot a
community's wastewater management program
The remainder of Part II presents information
to assist in performing each step ol the flow
reduction analysis approach depicted in Figure 6
(page 15) For each step several types ol informa
tion are provided, depending on the complexity
ot the analysis involved, including (1) purpose of
the step. (2) data and information needs for
executing the step, (3) suggestions about a
procedure to follow. (4) examples ol possible
methods ot calculation or analytical procedures.
and (5) observations on important factors to
consider in carrying out the analysis Although
the presentation is linear in that steps are
described in sequence, the approach illustrated
in Figure 6 (page 15) is intended to be nonrestnc
live as exhibited by the following features o! the
guidance'
An emphasis on alternatives As exemplified
by the loop in Figure 6. the flow reduction
analysis approach is intended to result in an
array of potentially woikable programs each
of which is then analyzed and refined A 'first
cut program" is identified quickly to provide
a tangible benchmark for evaluation and to
obtain insight into information needs for pub
lie involvement and lor program implemen
tation The methodology then shins emphasis
toward identifying and evaluating alter
natives which may be either modifications ol
the first-cut program or entirely new
approaches
Practicality Although theie are exotic meth
ods of achieving flow reduction that may be
appropriate in certain situations, the method
ology developed here stresses practical mea
sures which will usually apply to an average
community's circumstances
Consideration ol both monetary and
nonmonetary costs and benefits The
approach recognizes that monetary savings
are not the only consideration in elective
program planning - a myriad ol social.
political, economic and environmental ellects
may alrT be associated with each alternative
and we front equal consideration Thus.
maximizing total community wellare through
a water saving/flow reduction program is
emphasized
blank
-------
... HOW BSDUCT10N MEASUHBS
a'Av fc *i U*UL Jt-*. I - V T\ '^.1* .*.,. 1
Figure 7 Major Components Ol A Flow Seduction Piogiain
An emphasis on public participation. The
approach recognizes that successful
development and implementation ot a flow
reduction program recruires understanding
and support from community officials and the
public. An effective public information effort is
crucial to developing this needed support
and to fostering informed public input. Input
from a range of "publics" is essential through-
out program planning to determine the
acceptability of various options, to obtain
insights about potential effects previously
overlooked, and to encourage interest in the
program's objectives. Thus, active coordina-
tion with, and support from, water supply and
energy utilities as well as from businesses,
industries and public agencies is a hallmark
of the approach.
It is also recognized that participation by the
general public in developing the flow reduc-
tion program through workshops or public
information meetings, can and should be
coordinated with public participation for facil-
ities planning, both lor efficiency and for
clarifying the relationship between the two
processes
An iterative process. Although the approach
is portrayed as a sequence of steps, the
methodology is in fact open ended at every
phase. Program components are added.
subtracted or modified as more information is
obtained about costs and benefits. Public
input may in rum provide more information
about costs and benefits necessitating further
redesign of program alternatives, and so forth
Examples provided with the various steps are
intended to show how needed calculations
can be performed and how the cost-benefit
analysis of program alternatives can be
carried out. Thus they are illustrations of how
one can go about the analysis, rather than
cookbook recipes to be followed to the letter.
and modifications may be necessary to suit
each particular case.
Emphasis on flow reduction measures. In
this document emphasis is placed only on
those measures that would result in reducing
flows into the wastewater facility. Within this
conte:-ct. flow reduction measures are consid-
18
-------
ered to be a subset of all water conservation
or water saving measures Thus throughout
this document the terms "flow reduction",
"water conservation", and "water saving" are
used Interchangably, even though water con-
servation measures unrelated to flow reduc-
tion (e.g.. technicjues for saving water used in
outside lawn irrigation) are not considered
herein.
More detailed information on individual
flow reduction measures is provided in
Appendix B to assist in evaluating the various
components of a first-cut program.' additional
detail on cost-effectiveness calculations is pro-
vided in Appendix C and. additional sources
where more information can be found are
cited in Appendix D
The following material is organized by steps
(see Figure 6, page 15) with a general outline of
each step preceding discussion of it
-------
-------
A. Is Flow Reduction Analysis Required?
1. Statement of Purpose
The purpose of this step is to determine
formally, according to the criteria set forth in EPA's
Cost-Effectiveness Guidelines, whether or not a
flow reduction analysis is required.
2. Data and Information Needs
The data required to respond to this initial
step should be readily available from the facil-
ities planning effort and include'
Existing average daily L ase flow (ADBF) from
the area ADBF includes flows from residential
commercial and institutional sources, as well
as industries with flows of less than 25.OOO
gallons per day (gpd). (See Cost-Effectiveness
Guidelines, Section 8b, in Appendix A)
Current population of the applicant
municipality Note that the definition of
"municipality" in the Construction Grants
Regulations applies to special districts such as
water, sewer, or sanitary districts that provide
wastewater services to the surrounding com-
munity. Excluded are those special districts
(e g., an airport) which do not serve the
surrounding community. If there are multiple
municipalities within the planning area one
or more may be exempt if the exemption
conditions are satisfied, even though the
analysis is required lor other communities in
the area.
Knowledge of whether exemption from flow
reduction analysis has already been granted.
3. What To Do
Determine whether the existing ADBF lies
below 7O gallons per capita per day (aped)
Existing ADBF may be determined by
subtracting from the historical dry-weather
flow both dry-weather infiltration and specific
industrial flows which exceed 25.OOO gpd.
and then dividing by the existing sewered
resident population.
Determine whether the current population of
the applicant "municipality" is under 1O.OOO
Determine whether or not the Regional
Administrator has exempted the area for
already having an effective flow reduction
program in existence.
If one or more of these conditions is met the
applicant is exempt from the flow reduction anal-
ysis requirements. The applicant may
nevertheless choose to undertake a flow reduc-
tion analysis to obtain the cost savings and
nonmonetary benefits which a program can
bring to a community. Even when not required,
such an analysis is a grant-eligible part of the
wastewater facilities planning costs.
21
-------
R auction 02
I Assorr
t>oth existing and future.
of water use bytect
-br
- relationship between avera
-------
B. Establish Without-Flow-Reduction Condition
1. Statement of Purpose
The objective of this step is to determine and
document the water supply, wastewater flow and
related conditions as they exist and are projected
without flow reduction. This establishes a base
condition lor use in later analysis steps.
2. Data and Information Needs
Much of the iniormation needed for this step
should be available from the facilities planning
process Data such as populatioa water use and
wastewater flow characteristics are organized to
portray the "without-flow-reduction" conditioa so
as to establish a benchmark case against which
the "with-flow-reduction" condition can be
compared. Specific data needs and sources of
information are.
Iniormation on the breakdown of water use
by sectors within the municipality, even il
only approximate. To the extent possible, this
breakdown should include water use in the
residential commercial industrial and public
sectors and differentiation of seasonal from
nonseasonal use where appropriate. Water
billing records are the major source of inior-
mation on water use Where disaggregated
billing data do not exist, any significant
industrial users (i.e., those using more than
25.OOO gpd) can be manually separated
and the remaining water use divided
between residential and nonresidential use
according to meter size. Water production
records can be used along with billing data
to estimate the amount of water lost or
unaccounted for (Baumann et al., 198O) If
water use is not metered, estimates of residen-
tial and nonresidential use can be made
based on total water production and knowl-
edge of residential and nonresidential land
use patterns.
A breakdown of indoor versus outdoor resi-
dential use and categories of indoor use.
Indoor use may be approximated by winter
season residential water use in most cases.
For an average community, the breakdown
of indoor water use provided in Table 2 (page
5) should be fairly accurate.
Projections on water use by sector over the
planning period In most cases, forecasts ol
water use made by local agencies will not
be disaggregated by category ol use. II time
allows and the task is not too lormidable, an
attempt can be made to develop disaggre-
gated forecasts based on disaggregated
billing data (where available), local agency
water use projections, population trends and
forecasts, and other available information
(Baumann et al, 198O). Where the time,
resources or data required to make disaggre-
gated forecasts do not exist, lumped forecasts
already available can be used, basing future
percent allocations for each sector on
reasonable assumptions about expected
changes in these percentages over time
Unless there is reason to expect otherwise,
(e g, it is known that several large water
using industries will be moving into the com-
munity in the near future), the proportion of
water used by each sector can be assumed
to remain constant.
Estimates of existing and future average
wastewater flow conditions without consider-
ation of flow reductioa These estimates
should already have been made on a
preliminary basis as part of the facilities plan-
ning process. Four major components must be
considered in these flow estimates.
- Average daily base flow (see previous
discussion of Step 1, and Section 8b of the Cost-
Effectiveness Guidelines provided in Appen-
dix A for methods of estimating existing and
future ADBF) Note that allowances for future
increases of per capita flow over time are not
permitted.
- Present and expected future flows from spe-
cific industries which exceed 25.OOO gpd.
- General allowance tor future industrial
flows
- Nonexcessive infiltration and inflow.
Estimates of peak water use and waste-
water flows. In many instances (particularly
where there are significant outdoor residen-
tial or seasonal industrial water uses bearing
on the water supply system or where there is
large infiltration/inflow to the wastewater
lacility) peak hourly or daily water demand
and peak daily wastewater flows may be
overriding lactors in determining tho neces-
sary capacity lor water supply and waste-
water treatment facilities. In making these
estimates, consideration should be given to
eflorts planned or in operation to reduce
peak water demand or wastewater flows.
such as I/I analysis or flow equalization
The accompanying data sheets (Tables 4 and
5) are intended to be guides lor data collection.
Figures need not be entered in every space.
particularly under the peak columns. Certain
categories, however, will significantly affect peak
-------
Water Use Category
Average Dally Water Use
Present Projected
lOyrs 20yrs
Peak-Day or -Hour Water Use
Present Prelected
lOyrs 20yrs
Residential
Nonseasonal (= Indoor)
Seasonal
Commercial
Public
Industrial
<25.000 gpd
>25.000 gpd
Allowance lor Industrial Growth
Unaccounted-lor Water
Total
Table 4. Sample Data Sheet For Water Use Projections
daily or peak hourly estimates; e g, outdoor resi-
dential use on the water supply side (from exten-
sive sprinkling during dry periods) and seasonal
industrial flows on the water supply or waste-
water side (such as from fruit canning industries).
3. What To Do
The data acquired are used to determine the
system capacities needed to meet estimated
water supply and wastewater treatment needs
over the planning period. Both average and
peak conditions should be considered in making
these estimates of total water supply over time
and total wastewater flow over time. The data
are then analyzed to determine the necessary
staging periods for facilities construction and
expansioa- this determination of the without-flow-
reduction condition can be used in later compar-
isons of staging requirements lor the with-flow-
reduction conditioa A diagram similar to that
shown in Figure 8 may be useful for organizing
results and displaying them in a meaningful way
to the public.
This without-flow-reduction condition is then
evaluated to determine appropriate goals for the
flow reduction program in light of specific
characteristics of the community. These goals
may be in the form of specific targets that a flow
reduction program is designed to meet (e.g.,
reducing ADBF by x amount by year n). or they
may remain general (e.g.. attempting to
maximize total community net benefits). Speciiic
consideration should be given to G) selecting
target sectors for flow reductioa and (2) deciding
whether to focus on peak flows or average flows.
For purposes of carrying out the next step (i.e..
developing a first-cut program) explicit attention
should be given to whether the goal(s)
established are immediate or long-term, and why
4. Example
A community may find it particularly useful
to set a target lor the program il the municipal
wastewater treatment plant is nearing capacity
and the possibility of an overload looms ahead.
Such a community may want to set a target to
reduce average daily base flow or peak flow by
some percentage (say, 5 percent) over a
relatively short time period. An appropriate
longer-term goal might be to sustain the initial
success through, continuing public information.
5. Major Observations
The more disaggregated the data on water
use and wastewater flows, the better the
opportunity will be to focus on those sectors
and activities for which the flow reduction
potential is greatest.
The availability of data to a large extent
determines how this step will be carried out.
At the very minimum, residential use,
nonresidential use and public/unaccounted-
foi water should be distinguished, as well as
seasonal from nonseasonal residential uses.
This latter distinction is important since a
large portion of seasonal residential water
use is not discharged to sewers (Baumann.
et al, 198O>
24
-------
Wastewater Row Category
Average Daily Wastewater Flow
Present Projected
10 yrs 20 yrs
Peak-Day Waslewater Row
Present Protected
lOyrs 20 yrs
Comprise
ADBF
Residential (Indoor)
Commercial
Public
Industrial (<25,000 gpd)
Industrial (> 25.000 apd)
Allowance loi Industrial Giuwta
IntUtiatloalnflow
Excessive
Nonexcessrve
Total
Table 5 Sample Data Sn»*t Fat Wastowater Flaw Projection!
i Careful consideration should be given to the
classification ol apartment water use
Frequently, this use is classified as commer-
cial yet lor the purposes ol a flow reduction
program, apartment use will be responsive to
measures geared toward the residential
sector
i Clearly, these data needs require the cooper-
ation oL and perhaps assistance from, the
water supply utility Explicit consideration
should be given to what formal or informal
agreements may be appropriate to secure
these arrangements. Establishing good
working contacts with the water supply utility
early in the process will also prove helpful
(perhaps essential) to activities carried out
later in the analysis. Thus. Involving this
segment ol "the public" early in the planning
effort is one aspect of public involvement.
aimed toward the eventual task ol imple-
menting a flow reduction program.
-------
Expansion after 20 years
Expansion alter 10 years
10
15
Capacity ol proposed lacihry
Protected peak
flows (demand)
Protected average
daily flows (demandl
20 years
Figure 6 Sampl* Diagram Showing Capacity N«*ds Venus Tim* And Staging K»quii«m*nts For Th*
Without-new- Reduction Condition
26
-------
vVrV- . : i'.v'rX.:.'.:-,. ' ' >^^>.'f'J>.'--,v-,^.";.:'-^
OL Develop flKt-Ciit Pipgrdm
'' ' ' " "
Select individual flow reductioVmec&urw and : ";^\^
^synthesize a flow reduction
- structural measures
- economic measures -"
Define a suppprtina pubUc formation program^*,
Address implementation issues cmd develop art r3^;
implementation plan. .
-------
C-1. Develop First-Cut Flow Reduction Program
L Statement oi Purpose
The purpose ol developing a first-cut flow
reduction program is to provide the planner with
a tangible starting point lor the program analysis.
As implied by Figure 7 (page 18). this first-cut pro-
gram should consist of the three basic compon-
ents.
A first-cut package of flow reduction mea-
sures.
A first-cut plan for informing and involving
the public.
A first-cut Implementation plan.
Through the evaluation of this first-cut program,
the planner will get a better sense of the range of
attractive alternatives available; the various
"publics" (e,g.. utilities, community officials) who
should be involved, and why; and possible
implementation issues. This step should be
viewed as a learning experience, the final
product of which is a first guess as to what might
constitute a practical flow reduction program.
2. Data and Information Needs
In order to develop a first-cut flow reduction
program, it is necessary to know the flow reduc-
tion measures available for inclusion in such a
program and to have enough information on
each particular measure to be able to assess its
probable effectiveness and applicability given
the circumstances at hand To help meet these
information needs, this document does the follow-
ing.
Describes, in this subsectioa the categories or
types of measures available; for specific mea-
sures basic information about effectiveness,
limitations to use, and potential for savings
are provided." where appropriate. This infor-
mation can be used to make a preliminary
selection of measures to be included in the
first-cut program.
Discusses, in Subsection 3b. basic considera-
tions in formulating a public information/
involvement effort.
Discusses, in Subsection 3c, possible Imple-
mentation Issues and key elements of an
implementation plan.
Provides more detailed descriptions of spe-
cific flow reduction measures in Appendix B
(i.e, devices, pricing mechanisms, and
building codes).
Assesses the relative economic benefits of
common water saving devices In Appendix
C.
Provides examples of how to calculate the
annual net monetary benefits of common
water saving devices In Appendix C
a Categories bl Flow Reduction Measures
Flow reduction measures can be grouped
Into four baste categories which stress the thrust of
the implementation mechanism used for each.
structural, economic, legal/institutional and.
educational. Common flow reduction measures
in each of these categories, and the basic
characteristics thereof, are listed in Table 6 and
discussed In the following paragraphs.
1) Structural Methods. Structural methods of
saving water, and thereby reducing wastewater
flow, concentrate on improving efficiencies in the
physical aspects of water using systems. Generic
types of structural methods Include, leak detec-
tion and repair on the user's premises, metering.
flow control and water saving devices, recycling
systems, and hot water line insulatioa The follow-
ing discussions are Intended to provide a glimpse
of the range ol options available,- further detail on
individual devices is given in Appendix B.
a) Repairing leaks in water using fixtures in
homes and businesses can reduce wastewater
flow significantly. On premise leaks most com-
monly occur in faucets and toilets. Faucet leaks
usually are caused by worn washers. Replacing
the washer - an inexpensive task requiring little
time - is frequently all that is necessary. Toilet
tank leaks may result from a worn supply valve,
a tank ball improperly seated or a leaking tank
float. Many toilet leaks, though easy to repair, are
virtually invisible and thus may go undetected. A
colored dye placed In the toilet tank can be used
to detect leaks quickly and Inexpensively. Even
so, the relatively high cost of plumbing service
and low cost of water may cause many water
users simply to ignore leaks until they become
severe (California DWR1976). A public campaign
emphasizing the minimal amount ol effort
Involved In some leak repairs and their
beneficial effects could produce positive results.
b) Installation of water meters is designed
to sensitize customers to water use and water
price. Metering is essential If pricing mechanisms
are to be used as conservation incentives In
principle, the idea is to reduce water use by
raising the marginal cost ol water to the user from
zero to some positive amount Meter purchase.
Installatioa maintenance, reading and billing
require significant expenditures lor both new
connections and In existing unmetered
connections. In areas of the country where there
-------
fable 6. Characteristics oi Common How Reduction Measures
Measure
Description
Applicability
Effectiveness
Limitations
Structural Measures
Leak Detection
and Repair
Encouraging residences
and businesses to
actively detect and
repair any leaks in
fixtures such as faucets
and toilets.
Installation of Water
Meters
Meters installed to
measure water use.
thereby creating in-
centive to conserve and
permitting price systems
that encourage con-
servation
Installing Water Saving
Devices
A Showers and Faucets
1. Flow controls
2. Low How shower
heads
3 Aerators and spray
taps (lor laucels)
B Toilets
1. Flush valve
2. Shallow trap
3. Dual cycle
4. Toilet dams and
plastic bottles
or bags
5. Exotic waterless
toilets <
C. Water Saving Clothes
Washer
D. Water Saving
Dishwasher
Reduces water (low rale
Shower heads with lower
Dow rates than con-
ventional
Reduces water flow rate
by delivering water in a
spray.
Forceful flushing action
made possible by over-
size feed line and quick
release valve.
Smaller tank than con-
ventional: less water
retained In bowl.
Uses less water for
flushing liquid wastes
than solid wastes.
Through displacement.
removes water from the
active flush mode.
Use means other than
water lor eliminating
waste (oil, biological
decomposllloa Incinera-
tion, etc.).
May have either a suds-
saver lor reuse of wash
water or a variable
water level and tem-
perature control.
May feature cycle
adjustment controls.
General The potential
for leaks to develop and
contribute to wastewater
flow exists In all homes
and businesses
New or existing
construction
Retrofit (plastic Inserts
available).
i New construction.
New construction.
i Retrpflt.
Retrofit.
i New construction
Most common in com-
mercial establishments
(restaurants, service
stations, etc)
New residences.
New businesses unable
to Install flush valve.
New construction
Retrofitting existing
fixtures.
New construction.
Depending on type..
some useful only for
particular housing
densities or where
central sewer Is lacking.
Must be built Into
original equipment.
Must be built Into
original equipment.
Variable In areas with
large numbers of
substantial leaks, an
active public effort to
detect and repair them
could be very effective
Essential lor utilization of
pricing. Effective con-
sciousness-raising
measure which will
enhance effectiveness of
other flow reduction
measures Much of direct
water saved will likely
be from outdoor Irriga-
tion uses.
Reduces flow rates to
about 2 gpm.
Reduce flow rates to
between 1.5 and 3 gpm
(Conventional range Is
3 to 8 gpm)
Reduce flow rales to
between .75 to 2 gpm.
Estimated water savings
of 1 to 2 gallons per flush
over conventional type
New types very water
efficient.
Estimated water savings
of 1.5 gallons per (lush
over conventional
Estimated water savings
of 3.75 and 2 5 gallons
per flush lor liquid and
solid waste flushing.
respectively. Experi-
mental stages
Estimated water savings
of .7 to 1.5 gallons per
flush over conventional.
Effectively reduces
wastewater flow since no
water Is used
Water saved depends
on user. May reduce
water used for normal
cycle by 10 to 15 gallons
over conventional model
May reduce water used
for normal cycle by 3 to
4 gallons over conven-
tional model.
For hard-to-fix leaks, the
homeowner may not be
willing to pay the cost of
a plumber for repairs
Expensive, especially in
existing unmetered
connections.
Some public dissatis-
faction with low How.
but this should not be
prohibitive.
No major limitations.
No major limitations
None lor commercial use
Installation coots may be
drawback to residential
use
Occasional need for
double flushing Usually
not a problem with
proper desiga
Few manular'.ured in
USA Slightly more com-
plex to operate.
No major limitations
Generally expensive
Most have low public
acceptance. Some have
high energy demand
Suds-saver requires fairly
large service sink
No major limitations.
30
-------
Measure
Description
Applicability
Effectiveness
Limitations
E Pressure Reduction
Residential Water
Recycling
Insulation ol Hot Water
Lines
Economic Measures
Pricing Changes
Regulate the flow of
water lor individual
services or distributional
zones by Installing valve
to reduce pressure In
service lines.
Systems allowing the
same water to be used
lor a sequence ol func-
tions, each requiring
water of somewhat
lower quality.
New construction.
Retrofit
Appears more effective
lor multiple develop-
ments rather than single-
family dwellings.
Estimated potential
water savings of 20
percenl of total use.
Amount of water saved
Is variable but signifi-
cant Possible net savings
of 23 percent of primary
water used
Insulating pipes to
reduce lime it takes lor
water to become hot.
Most easily done In new
construction.
Estimated water savings
of 3 percent of Indoor
use: substantial energy
savings possible
May cause problem
with outside Irrigation
systems designed for
,. previous pressures.
Retrofit requires pro-.
tesslonal Installation
but likely still cost-
etlective.
Expense Public
acceptance may be low.
Difficult and expensive
In retrofitting.
Altering the water pricing
schedule to encourage
conservation. Trend
toward Increasing block
rate structure: peak
demand pricing.
i Can be useful In any
sector.
i Requires metering.
Variable. Depends on
water and sewer prices.
demand elasticity, per-
centage of water used In
various water-use
categories, and other
(acton.
Public acceptability
may be low. May be
economically regressive
Demand Metering
Measure both volume of
water used and time of
uso price is higher
during limes ol peak
demand
Legal/Institutional
Measures
Changing Building and
Plumbing Codes
Legally mandate instal-
lation ol water saving
devices or fixtures
Educational Measure*
Public Education/
Communication Program
Program to educate
public about flow
reduction and to obtain
public support and help
In program implementa-
tion. Achieve habit
changes.
Potential alternative In
areas replacing meters
or previously without
meters.
Uncertain. Still In
developmental stage.
New constructloa
Replacement for old
fixtures.
Some areas have
estimated that sub-
stantial savings would
result In long run.
Changes affect Indoor
use and would thus
directly reduce waste-
water flows.
Still In experimental
stage. Complications In
meter design.
May take several years
to see significant results.
Mandated retrofitting
would likely meet social
and political resistance.
Applicable and necessary
for the success ol any
flow reduction program.
Estimated water savings
of 5 to 10 percenl
although hard to
differentiate effects of
education measures
from other measure!
No major limitations.
Information synthesized from: Feldman (1977),
Flack el al( 1977).
Hopp(1979),
Metcalf* Eddy. Inc. (1976),
Milne (1976),
and Nelson (1977).
-------
is considerable outdoor water use (e.g.. lawn
sprinkling in the western stales), much of the
reduction in water use brought about directly by
meter installation will likely be due to decreased
outdoor use ol water» that portion ot reduced use
will have little or no effect on wastewater Hows.
However, metering is an etlective consciousness-
raising measure which will enhance the effective-
ness of other measures and help generate public
acceptance of the flow reduction program.
c) Installing flow control/water saving
devices and appliances in residences (and the
commercial and public sectors) has proven an
effective means of achieving water use
reductions. This measure can be applied both as
a retrofit plan for existing structures and as part ol
a conservation plan in new constructioa Many
communities have carried out retrofit programs
with simple flow controlling devices, resulting in
reduced water use and reduced household
water and energy (to heat water) costs. Table 6
provides examples ol some common devices
suitable lor both retrofit and new constructioa
d) In-house recycling is on effective way to
reduce water use and wastewater flow - approx-
imately 3O percent ol the water used in
residences is recyclable and would yield a net
saving of 23 percent of the primary water that
would be used without a recycling system
(McLaughlia 1975). It usually involves reusing the
"grey" water resulting from certain household
activities (e.g., bathing or clothes washing) lor
other uses which do not require clean, pure water
(e.g., toilet (lushing).
As estimated in 1975, household storage and reuse
of water appeared to be cost-effective when the
combined water supply-wastewater costs were at
least $1.5O/1OOO gallons (Schaefer, 1975). In the
past, relatively low water and sewer rates have
limited the situations in which recycling systems
appear cost-effective. These rates have been
rapidly increasing in some areas, however, and
recycling systems may become increasingly
economical. Moreover, they may be useful
options In areas whore water is in critical supply
or where waste disposal and treatment systems
are severely loaded
Although an effective flow reducing measure, the
installation ol recycling systems will remain a
consumer's choice. Aside from informing the pub-
lic about grey-water reuse in public Information
activities ol the flow reduction program. It is
unlikely that in-house recycling will play an
important role in an average community's broad-
based program.
e) Insulation of hot water lines reduces the
amount ol time needed lor water to become hot
once turned on. Less water is thus wasted waiting
lor the hot water to arrive. Although insulation is
most easily installed at the time ol constructioa it
can also be installed on portions of piping in
existing units exposed in the foundation area .
(Nelsoa 1977} While this measure is more effective
as an energy saver, it has been estimated that
water savings of 3 percent ol Indoor use may
result (Feldmaa 1977). ,.
2) Economic Methods. Encouraging flow
reduction through water conservation by eco-
nomic methods can be accomplished through
action by the water or wastewater utilities While
pricing Is the primary economic measure for
achieving water use and wastewater flow
reductions, "peak demand" metering and other
incentives or penalties hold the potential lor
producing positive results. More detail on pricing
mechanisms is provided in Appendix B.
a) Pricing structures are being changed by
an increasing number ol utilities from the tradi-
tional declining block rate to either a uniform unit
rate or increasing block rate. An increasing block
rate provides the greatest price incentive lor con-
servation by raising the price ol each additional
quantity ol water used,
In designing an appropriate rate structure, it is
important to consider the elasticity ol demand lor
water use in each sector. Knowledge about this
demand elasticity (the ratio ol the percentage
change in quantity demanded to percentage
change in price) helps to assess what reduction
in water use may occur in each sector due to a
given price Increase. For example, while a
laundry operation has little flexibility in Its water
use and would not respond signlllcantly to price
changes, certain industries and commercial
operations (e.g, car wash) may be led by price
increases to change their production processes or
to institute recycling schemes to conserve water
(Call 1978).
Basing wastewator charges on nonseasonal
(i.e.. winter) water use using cm Increasing block
scale provides Increased incentive to reduce
Indoor water use. Ol course, the use ol price
changes to promote conservation requires
metering.
b) Demand metering is essentially a
structural means ol implementing dally peak
demand pricing. It involves measuring incremen-
tal volumes ol water used and the time ol use
and then designing a pricing structure which
charges more (or quantities ol water used during
peak hours.
c) Other economic incentives lor reducing
water use include rebates and tax breaks lor
-------
Additional Cost/Fixture
' ' i Above Conventional Cost (S's) ' ,, Water Saved
New. Remodel or Retrofit Material Percent of '
Fixture/ Activity Routine Replacement (+ labor) Conventional Use
Toilets
Showers,
Kitchen and ...
Lavatory Faucets
Pressure Seducing Valve
Hot Water Pipes
Clothes Washer
Dishwasher
Education
Total
0-6 1 -5 (+0-5)
0-5 l-5(+0-4)
.0-2, , 0-2(42)
30. 30 (+20)
0-20° 50 (+80)
20-30 300 (+ 20)
0-10 300 (+ 10)
S2/Resldence/Year
a. Insulation at 50c/toot: counteroaiancea oy less pipe.
b. Low estimate to allow for 50% baths.
c Low estimate to lessen double counting.
d Low estimate to allow for households without dishwashers.
30-55
25-50
10-30
15-25 ,
(ot In-house use)
4-12
' (of hot water)
35-65
0-50
10-25
(of faucet use)
gpcd
e-n
2.5 - 5"
5-1
3-6=
1-2
3-6
-5"
.5 - 1.5C
17-29*
Energy Savings From
Hot Water Heating*
(1CP BTUVcaplta/day)
1:1-2.2
0.2-0.4,
1.1 - 2.2
0.8 - 1.5 -
1.5 - 3.0
0.4 .
0.2 - 0.6
4.5-8.9»i
e. Assumes pressure reducers applicable to 30% of residences.
I Assumes 100% energy efficiency: this Is a conservative
estimate of energy savings.
Source: U.S. EPA (1979).
Ranges ot Costs and Water/Energy Savings From Indoor Residential Conservation (Conservative Estimates)
water conserving measures. Penalties or lines for
the wasteful use ol water may be counter-
productive and should be reserved lor severe
crisis situations.
3) Legal/Institutional Methods.
a) Changes in building and plumbing
codes are means ol legally requiring the use ol
water saving fixtures in new construction or
remodeling. Particularly in areas experiencing
growth, such changes can result in significant
reductions in water use. Code modifications are
probably the most effective means ol ensuring
long-term implementation of conservation mea-
sures (US. EPA. 1979) and hence should be
carefully considered in developing a first-cut flow
reduction program. It has been estimated that lor
the Washlngtoa D.C. area a revision of plumbing
codes to incorporate water saving/flow reduc-
tion devices would, within fifteen years, save as
much as 26 million gallons ol water per day in
rer'.dential use alone (Schaeler, 1975). Appendix B
provides additional information on building
codes.
b) Placing legal restrictions on new fixtures
ottered for sale is a way of ensuring that new
fixtures purchased within the state, county, or
political entity to which the restrictions apply will
be ol the water saving variety. Some states.
including New York and California have already
passed laws of this type.
c) Requiring water and energy labeling of
new fixtures and appliances provides a way for
consumers to compare the water and energy
efficiency ol various appliances prior to purchase
and inlorms consumers as to the overall
quantities ol water and energy used by these
appliances. Some manufacturers are already
providing this information on a voluntary basis.
4) Educational Methods. Significant water
savings can be achieved by educating the pub-
lic about changes in water-using habits. Turning
faucets off while shaving or brushing teeth and
taking shorter showers are examples of minor
habit changes which can produce positive
results. Increasing public awareness about these
possibilities (or water savings can be
accomplished as part ol an overall public infor-
mation program. (Public Information program
planning is further discussed as a separate task in
this step.)
b. Costs and Water/Energy Saving
Consequence* of Individual Measures
Knowledge about the costs and the water
and energy savings possible from individual flow
reduction measures is essential In developing a
practical first-cut program. Table 7 provides an
overview ol the range ol these costs and savings
pertaining to Indoor residential conservation
mear ure& Appendix C assesses the relative eco-
nomic benefits ol common water saving devices
-------
and provides examples ol how to calculate the
annual net monetary benefits associated with
these devices. The information in Table 6 (page
3O) along with that provided in Table 7 is
sufficient to allow selection of a reasonable set of
flow reduction measures to include in a first-cut
program.
3. What To Do
a SynthesiM a First-Cut Program
Developing a first-cut flow reduction program
is a subjective exercise which involves
synthesizing and evaluating the data and infor-
mation obtained thus far. Thus, based on
common sense and practicality, one makes an
initial selection of those flow reduction measures
which, when implemented together as a
package, seem to satisfactorily respond to the
community's wateVwastewater characteristics,
goals, budget, and potential for savings.
No first-cut program can be suggested here
as the "best" or the "right" one. The key to putting
together a program with strong likelihood of
success is to select flow reduction measures
which will be effective and appropriate for the
specific community where they will be
implemented Additional insight into the guiding
rationale and methods used in developing a first-
cut program is provided in another document of
this flow reduction series, where two case studies
are described. The following questions are
designed to stimulate thought and provide
direction in developing a first-cut program!
Given the present and projected water
use/wastewater characteristics, should the
program be geared toward meeting only
long-range goals or immediate goals as well?
Are there specific program/implementation/
timing features which should be included in
order to create a broad consensus of support?
(For example, should gradual implementa-
tion be planned so that per capita decreases
in water use are counterbalanced by increas-
ed numbers ol customers, thereby avoiding a
reduction in water utility revenues?)
Which measures can be eliminated lor
having effects which are too short or long
ranged to meet goals?
Are there barriers to implementation (e.g.,
cost, social acceptability) of any of these
measures which foreclose their consideration
in a practical program?
Is the price charged (or water and waste-
water services sufficiently high to make eco-
nomic measures (e.g., pricing) viable options?
Or is the price so low that people simply
won't notice a change toward "conservation"
pricing? ;
What community service groups are avail-
able to help carry out continuing public infor-
mation and public education programs and
perhaps to voluntarily distribute retrofit
devices to residences?
What are the key implementation issues
which must be addressed in the implementa-
tion plan?
The above questions point toward consider-
ation of the cost effectiveness, timing of effects
and social acceptability ol individual measures
in flow reduction program planning. It is also
important to consider the combined effects of
measures to be jointly implemented as part of an
overall flow reduction program. For example.
pricing is sometimes cited as an economic mea-
sure for which public acceptability is low; yet
substantial public support for conservation-
oriented price schedules has been obtained
when accompanied by an effective public infor-
mation campaign.
Perhaps more importantly, it is essential to
realize in designing a first-cut program
(particularly when specific targets are to be met)
that combinations of several flow reduction mea-
sures do not usually result in strictly additive
water savings. Frequently, adding the expected
water savings from two or more individual mea-
sures, and taking the sum as the expected total
water savings from implementing them together
as a package, will result in a significant degree of
double counting. For example, since both water
saving shower heads and pressure reducing
valves affect water use In the same manner. (Le,
by reducing the flow^rate). the total amount ol
water saved is some amount less than the sum ol
the water saved by each individual measure.
Certain measures, such as public education to
accomplish changes in water use habits, produce
savings that may be fully additive to the savings
achieved by other measures. Combinations of
more than two flow reduction measures create
more complex interrelationships, and the resulting
water savings will be dependent upon
characteristics ol the particular community (Flack.
et al. 1977). Although attempts'might be made to
calculate or measure the combined effects of
such measures, the informed judgment ol
planners or engineers familiar with local water
use patterns may be adequate lor planning
purposes. Double counting Is discussed more fully
in Appendix C.
-------
b: Define q Supporting Public Information
Program
An effective public Information program
which generates discussion of and support for the
flow reduction measures being considered and
supplements the implementation plan (discussed
in the next section) is vital to a flow reduction pro-
gram's eventual success. Beginning to think about
the elements of such a program, and getting
them down on paper, is an important part of the
first-cut program development effort. Public infor-
mation programs can be designed to suit a wide
variety of community goals and budgets and
should be tailored to fit community needs
accordingly. Four categories of elements
comprising such a program can be identified
(after Lottie. 1977>
Direct mail (e.g., water bill inserts, newsletters).
News media (e.g.. news stories, radio and T.V.
public service announcements).
Personal contact (eg., telephone calls, public
meetings or hearings, speaking at schools
and service clubs).
Special events/exhibits (eg., displays in
shopping centers, county lairs, schools).
Several different mechanisms of information
dispersal should be considered for inclusion in
the program to ensure that most of the public is
reached. For example, giving talks in local
schools and at service organization meetings,
sending flyers with water bills, and writing articles
for community newsletters would likely bring the
program's needs and goals to the attention of
most of the community. Repeated messages over
a period of time, as opposed to a one-shot effort is
also essential.
The cost of carrying out an immediate crisis-
oriented public information program or of getting
a long-term program underway can vary greatly.
For example, it has been estimated that total
annual program costs lor a residential
community of 25.OOO could range from S2.OOO
to $15,OOO depending upon such lectors as
availability of water/wastewater agency staff as
opposed to hiring outside personnel, and local
design and production costs for things such as
informational brochures and films. Substantial
savings and increased public support can often
be realized by seeking the voluntary help of
local youth groups or service organizations (Lottie,
1977). An effective public information program
can be designed to lit the budget limitations ol
almost any community, As with the set of selected
flow reduction measures, the type ol program that
is appropriate will depend upon the particular
community's circumstances.
c. Address Implementation Issues and
Develop an Implementation Plan
The ability to implement each individual flow
reduction measure should be a criterion lor
judging whether or not to include it in the first-cut
flow reduction program. Thus, a preliminary
implementation plan should be developed for
the program as a whole since it is futile to
proceed with further evaluation and modification
of a program which stands little chance of being
effectively implemented. In developing the
preliminary implementation plan, important
questions to consider include,
Does the agency or entity designing the pro-
gram have the authority to implement all
phases of the program, or is it necessary to
aco^iire authority or secure cooperation from
another source? (Note that this is not a trivial
matter since EPA's Cost-Effectiveness Guide-
lines contain specific language regarding
adoption of measures that lie "within the
implementation authority of the grantee or
another entity willing to cooperate with the
grantee.")
Even if implementation authority exists, does
the ability to effectively implement the pro-
gram hinge upon obtaining the support ol
key agencies, entities, individuals, or the
general public?
Can implementation ol the program be
accomplished more efficiently and
expeditiously if an attempt is made to
coordinate activities with other programs?
Related programs may be those involving
water conservatioa energy conservation or
infiltration/inflow.
Will the budgetary costs of the program
exceed available funds? Are other funding
sources available?
Because an effective implementation plan is
a crucial component ol the flow reduction pro-
gram, it should at a minimum contain the follow-
ing elements!
Milestones or timetables designating when
certain phases or components ol the program
will take effect and when related Implemen-
tation actions or products will be completed.
Sources of funding lor the various program
components.
Identification of who or what entity is
responsible for implementing each aspect of
the program. Commitments (written where
necessary) will eventually need to be
obtained from those being relied upon lor
some aspect ol implementation when a final
flow reduction program is selected
-------
Package of now Reduction Measures
A mass retrofit program Involving tree distribution and
Installation ol toilet dams and plastic shower heads, as well
as free distribution ol dye tablets and common washers lor
detecting and repairing residential leaks.
A public education effort, as part of the broader public
Information program, oriented toward changing the public's
water use habits.
Change to increasing block rate structure provided system
is metered.
A Public Information Plan
Send flyers out with water bills explaining the need for and
encouraging support of water saving/flow reduction
measures.
Publicizing the program through radio/TV public service
announcements, talks In schools and to organizations,
special exhibits al central locations.
Establishing a telephone hot line where the public can
obtain answers to cjuestions about the program.
An Implementation Plan
Organizing a voluntary assistance effort by local service
organizations In distributing and Installing devices, manning
the telephone hot line as well as special exhibits (with
needed training provided by utility staff).
Soliciting contributions of free radio/TV time by local stations
for brief advertisements, talk shows, and the like.
Securing agreement from water supply utility to support
program by sending Dyers with water bills, training volunteers.
sending staff persons to speak In schools, and the like.
table 0. Sample now Reduction Program Foz Hypothetical Community with Relatively Immediate now Seduction Coals
Number of man-years needed lor implemen-
tation of the various program components.
Building code changes, for example, will
require time to write the regulations, get them
approved.
Neglecting to contact key persons/groups/
entities in the development of an implementation
plan may result in the selection of implementa-
tion mechanisms much more costly or difficult to
carry out than is necessary, may render partic-
ular program components ineffective, or may
cause the entire program to fail. In short, the
success of the program ultimately hinges upon
this phase of program development.
Providing a mechanism for public input at
some point in the development of the first-cut flow
reduction program may prove invaluable. Much
time, energy and resources can be saved if mea-
sures unacceptable to the public are flagged
early in the process and either modified, ;
eliminated or more clearly explained in the pub-
lic information program to obtain public support.
In addition, the efforts of people or groups willing
to voluntarily assist in program development or .
Implementation can be utilized, but a means ol
identifying these persons or groups early in the
process must be provided Thus the public infor-
mation and involvement efforts are closely
related to the implementation effort and vice
versa
For those communities without an active, full-
scale public participation effort for Step 1 facilities
planning, a special meeting or workshop may be
scheduled to obtain public input on flow reduc-
tion at this stage. Note that such a meeting is
grant eligible under Step 1. It may be best not to
present an entire llrst-cut program to the public at
this time since (1) this could give the impression
that decisions have already been made when
they really have not. and (2) the benefits and
costs of a program have not yet been calculated
(see Step D). At this stage, public input should be
sought on measure-specific effects and specific
implementation features rather than on a pro-
gram as a whole. The initial strategy is to create
an atmosphere of openness and practicality
which avoids strong public reaction to or fear of
preliminary ideas but which introduces enough
ideas to test public preferences. Because of the
importance of public input and involvement a
separate step (Step F) is entirely devoted to a
discussion of this aspect of program development.
It is also important however, to begin public
involvement early and to continue it throughout
the flow reduction analysis process.
4. Examples
a Sample Programs
The following sample programs are not
meant to be directly applicable to any particular
community but are examples of the types ol pro-
grams communities in particular situations might
consider.
First a community faced with the prospect ol
a wastewater or water supply facility rapidly
nearlng capacity might consider developing a
program which will produce relatively
immediate reductions In water use or wastewatei
flows. Specific elements of the three main flow
reduction program components which might be
Included are outlined in Table 8.
On the other hand a community is In a
markedly different position If it has sufficient
reserve capacity In its water supply and waste-
water treatment facilities to fulfill its Immediate
needs. It can afford to look a few years Into the
future and It may be attracted by the potential
long-term benefits ol flow reductioa As a result it
might adopt a relatively aggressive, long-term
program such as the one outlined in Table 9.
-------
ackctge of now Seduction Measures
Building code changes to require:
- Installation ol meters with all new connections:
- Installation ot pressure reducing valves In new construction
and major remodeling wherever service line pressures
exceed 60 psig pressure is reduced to a maximum ol 50
psig tor residence's; and
- installation ot water saving fixtures and appliances In all
new construction and major remodeling.
Water and energy-use labeling ol all plumbing fixtures and
water using appliances. Includes setting standards lor water
and energy use which allow certain models to be labeled
"water and energy ellicient".
1 Gradual (le.. over a period ol years) installation ol water
meters in all existing water connections. (The equity and
consciousness-raising aspects ol this measure are judged to
outweigh the economic aspects.)
1 Institution ot an increasing block rate structure.
' Provision ol a tree water audit service oriented toward
helping water users In existing buildings find a.nd repair
leaks and develop their own in-residence retrofit program.
The service could also provide a list of qualified contractors
to do retrofitting and a catalog of locally-available practical
water saving/flow reduction measures.
1 Public education to change water using habits such as
turning faucets off while shaving and brushing teeth, and
taking shorter showers.
A Public Information Plan
Elements similar to those displayed In Table 8 for a
community program having Immediate goals but carried
out less Intensively after the beginning program initiation
activities.
Establishment ol media contacts so that news Items will be
covered on local radio/TV newscasts, persons familiar with
the program will be Interviewed on talk shows, and the like.
Establishment of contacts with community groups staging
special events (e.g.. country fairs) periodically so that flow
reduction exhibits can be displayed
An Implementation Plan
Obtaining support/assistance from water supply utilities)
tor installation ol meters and pressure reducing.vatves.
Institution ot Increasing block rate structure, promotion of
flow reduction through Inclusion of flyers with water bills.
and other actions as appropriate.
Obtaining voluntary help from local service groups and
individuals for overall program promotion
Obtaining advice/support from plumbers and building
Inspectors In instituting the building code changes.
Obtaining support from manufacturers/retailers In water
and energy-use labeling.
table 9. Sample Flow Reduction Program Foi Hypothetical Communltr With Kelattrerr Long-Term, Aggmstr* Goals
b. Calculating Expected Reduction in In-
oox Residential Water Use From Implementa-
on ol a Flow Reduction Program -
, Hypothetical Case
For purposes of Illustration it is assumed that a
ypothetical community has the following
haracteristics relative to the analysis 0) a 198O
opulation of 18.5OO) (2) a population growth rate
f 3 percent per year/ (3) an average indoor resi-
.ential water use of 65 gpcd. It is also assumed
lot in 198O, implementation of a flow reduction
irogram begins consisting of the following mea-
ares,
A retrofit program which includes free
distribution of toilet dams, plastic shower
head Inserts, faucet washers, and dye tablets
for leak detectioa as well as information on
how to install the devices, use the tablets, and
fix simple leaks in toilets and faucets. (Other
distribution methods and an assessment of
their relative effectiveness are provided in
Appendix B.)
Building code changes which will require all
new residences to be equipped with shallow
trap toilets, low flow showerheads,,water
meters, and (where line pressures exceed 6O
pounds per square inch gage (psig)) pressure
reducers which reduce pressure to 5O psig.
A public information and education pro-
gram designed to support the retrofit and
building code components of the program by
distributing flyers in the water bills, talking in
schools and at organizational meetings, and
arranging various special exhibits. Along with
supporting other aspects of the program, the
public education effort is expected to raise
public consciousness and concern about
water saving/flow reduction and bring about
additional savings of 1 gpcd due to increased
awareness of water value and water wasting.
Changes in habits, such as turning faucets off
while brushing teeth or shaving, taking
shorter showers, and the like, can be expect-
ed, resulting in at least minor reductions in
water use.
An implementation plan similar to that
outlined in the sample program. Table 9.
Calculating the expected total indoor residential
water savings from the program involves.
Determining how each program element will
affect per capita water use in an average
residence where it is implemented
Adjusting water use reduction estimates
wherever necessary to avoid double
counting (see Appendix C>
Determining how many residences (or what
portion of the population) will be implement-
ing each program element each year in the
time period This will be estimated based on
the rate of population growth, the percentage
37
-------
Program Element
Water Savings
(gpcd)
Timing of Eflect and
Percent Implementing Measure
Retrofit
Tbllet dams
Shower head Inserts
Tbtlet/laucet leak repair
Total
Building Code Changes
Shallow trap toilets
Low flow shower heads
Pressure reducing valve"
Metersb
Total
Public Education
7.5
4.0
10
125
75
40
20
10
145
10
Becomes etlecttve In 1981: 30% Install devices
and check tor leaks: population using devices
each year Is 30% ol 1961 population.
Becomes eftecttve In 1984; eBectlve In 100%
ol new residences.
a. Low estimate to allow tor double counting and expectation
that pressure reduction Is reaulred In 40 percent ot new
residences
Becomes ettecttve In 1981; remains constant
each year.
b. Expected savings result from Increased public conscious-
ness about water use.
Table 10. Effects of Program Elements On Residential Indoor F»r Capita Water Dw For Hypothetical Community (gpcd)
ol residences expected to actually implement
the measure, and the time when the program
elements become effective.
The hypothetical ellect ot each program element
on indoor, per capita water use is shown in Table
1O.
After the projected population lor each year
is tabulated, the information in Table 1O is applied
to determine the total savings in indoor water use
lor each year Irom each element ol the program,
as is shown in Table 11. In that table, the horizontal
sum ol the expected water savings from each
program element is the total expected indoor
water savings for that year.
Finally, Table 12 compares residential indoor
water use with and without the flow reduction
program and shows the percent of indoor water
use saved as a result ol the program. Notice that
the percentage oi indoor water use saved
decreases until the building code changes take
effect in 1984, after which residential indoor water
savings from the flow reduction program
continually increase.
Complete consideration ol the potential lor
community water savings will include similar pro-
grams and calculations lor the commercial pub-
lic and nonspecilic Industrial (l.e. those
discharging less than 25.OOO gpd ol wastewater)
sectors. The sum ol these estimated water savings
Irom all sectors will constitute the total expected
community-wide water savings. The extent to
which these estimated water savings will allow
lor an alteration oi the design capacity ol the
planned wastewater treatment plant will depend
upon the relationship between peak flows and
average daily base flows and the relative
amount of inliltration/lnflow entering the treat-
ment facility. Similarly, resulting changes In
operating and maintenance costs will depend
upon .the particular treatment plant and commu-
nity wastewater flow characteristics.
5. Major Observations
Belore the first-cut program is well defined, it
may be helpful to at least outline the main
components ol a complete program so that a
tangible focus (or discussion Is available
during early contacts with the water supply
utility, other related agencies and
representatives ol the public Consider in this
"straw man" program.
- All sectors of water use (i.e.. residential com-
mercial public and non-specific industries>
- All major components of the flow reduction
program (l.e.. a set ol Dow reduction mea-
sures, a public Information program, and an
Implementation plan),
- An estimate ol first-order effects (i.e.. program
costs, and effects on water use and waste-*
-------
Savings from
Year - Population ,; - - Retrofit0
1980 18.500
1981 19.055 .071
1982 19.627 071
1983 20.216 .071
1984 20.823 .071
1985 21.448 .071
1990 24.864 .071
1995 28.823 .071
2000 33.414 .071
a. Determined by multiplying the per capita per day savings
from the retrofit program (12.5 gpcd) by the 1981 popula-
tion (19.055) by the percent Installing the devices (.30).
b. Determined by multiplying the expected savings from the
building code changes (14.5 gpcd) by the increase In
Savings from Savings from Total
Building Code" Education Program0 Savings
.019 090
.020 .091
.020 .091
.009 .021 .101
.018 .021 .110
.067 .025 .163
.125 .029 .225
.191 .033 .295
population over the previous year, and adding to this
amount the total savings from building code changes In
the previous year.
c Determined by multiplying the 1 gpcd savings by that
year's population.
Table 11. Expected Residential Water Savings From Flow R»dv
Program Elements For Brpotnetical Communitr (mad)
water flows over time).
Significant institutional constraints related to
separate administration ol the water supply
and wastewater treatment systems may limit
program implementation and effectiveness.
For example, the presence of high fixed costs
on the water supply side may lead to the
encouragement of maximum system use to
help "pay off" the system If not dealt with
explicitly in program design and implemen-
tatioa this may frustrate efforts to achieve
flow reduction (Schaefer. July 1975).
Flow reduction devices often become cost-
effective from the community point of view
only when water supply, wastewater treat-
ment and hot water energy costs are
integrated This integration of functions may
not occur due to the utilities' institutional
separation and their differing economic
viewpoints (Schaefer, July 1975). As energy
costs escalate, however, flow reduction
devices will become increasingly cost-effec-
tive.
Many flow reduction measures - even ones
which have major cost saving advantages -
will only be adopted if they have public sup-
port and if the wastewater utility has authority
to implement them or can obtain the cooper-
ation of another entity having the needed
authority. When the wastewater utility is an
Independent authority, not responsible to the
community in any way outside the provision
ol wastewater services, this vital implementa-
tion link may be difficult to obtain (US. EPA,
January 1979) unless a cooperative
relationship with the water agency is
developed from the outset ol the flow reduc-
tion analysis
A major disincentive lor utilities to undertake
conservation programs is the very real
possibility that a successful program could
cause a decline in the utility's revenues.
Because fixed operating costs comprise a
large proportion of a utility's costs, this threat
ol revenue erosion may necessitate a rate
increase. It has been indicated by some,
however, that the percentage increase in
price needed would not be great. For exam-
ple, Milne 0976) has pointed out that a 16 per-
cent decrease in peak seasonal water use
might necessitate only a 1 to 2 percent rate
increase. An average water conserving
homeowner would still experience a reduc-
tion in water bills. The public information pro-
gram should explain to water users what the
net effect ol the conservation measures.
including any rate increase, will be.
Installation ol water saving devices may
have little effect on wastewater capacity
needs if there is substantial Infiltration and
inflow into the system. A more complete
discussion ol the relationship between flow
reduction and infiltration/inflow is given in
Part I (page 9).
Some lessons learned from the California
DWR Pilot Conservation Program (October.
1978>
-------
Average Dally Indoor Water Use
Year Population Without Program" With Program"
1980 18,500
1981 19.055
1982 19,627
1983 20,216
1984 20.823
1985 21,448
1990 24.864
1995 28.823
2000 33.414
a. Determined by multiplying average Indoor residential water
use ol 65 gpcd by the population for each given year.
1.203
1.239
1276
1.314
1353
1.394
1.616
1.873
2.172 '
_
1.149
1.185
1.223
1.252
1.284
1.453
1.648
1.877
Percent of Indoor
Water Use Saved
. '
7.3 ;
7.1
7.0
75
7.9
10.1
12.0
13.6
b. Determined by subtracting Irom the previous column the
total water savings calculated In Table 9.
Table 12. Comparison Of Indoor RMUtonttal Water Us* With And Without Flow Reduction Program For Hypothetical
Community (mad)
- For a retrofit program, a short intensive
distribution ol devices is most effective.
- A promotional campaign for the program is
essential.
- A telephone hotline is a useful way for the
public to get information and answers to
questions such as how to install various
devices.
- Ol all retrofit devices lor toilets tried, toilet
dams were the most popular and saved the
most water. (It should be noted, however, that
plastic displacement bottles and, particularly
plastic bags are becoming the most popular
toilet retrofit devices.)
Increasing numbers of municipalities are fol-
lowing the policy of billing the cost of waste-
water treatment directly to the homeowner as
a percentage of the water bill (Milne, 1976).
This helps to increase awareness about the
connection between water use and waste-
water flows and provides an additional con-
servation incentive. When and where
possible, a more equitable conservation
policy would be to bill homeowners lor
wastewater services as some percentage ol
indoor water use - outdoor use has little effect
on wastewater flows.'Since having two
meters at a residence is generally
impractical, this question of equity may be a
key consideration in determining whether
wastewater charges will be in proportion to
water use .or based on a flat rate. A
compromise approach is to set wastewater
charges as some percentage of average.
winter month water use since most of this
water Is used indoors and is discharged to
sewers.
40
-------
I
Step D. Determine '
«: Calculate nibnetcQY benefits and
';f^t ^tewiiter utility v^!^
gg to the water supply utility
^.:-'-io" water users (only those costs and tie:
^..j-:.%»*" «J jj'u-*«.^.i 4 t.in;iin^' ^uiuaw ,»m.«J WWMM.4U*
. additional to utilities' costs
tderitilyjnonmbnetary benefits
fromenvlronmentciVsoclal/econ6mic effects ot
1
flow reduction
Qualitatively evaluate relative importance
-' i:' honrhonetary benefits and costs vis-a-vis moMicn
benefits and costs
Preceding page blank
-------
D, Determine Costs and Benefits of the How Reduction Program
L Statement of Purpose
In selecting a fined flow reduction program, it
is essential to have a basis lor evaluating each
possible program and lor comparing the various
program alternatives. This step focuses on a
method of evaluating the lull range of commu-
nity-wide costs and benefits associated with a
given program alternative. These costs and bene-
fits are of two kinds, monetary and nonmonetary.
Thus, Step D in the flow reduction analysis has a
two-fold objective,
To develop a comparison of the monetary
benefits and costs of the flow reduction pro-
gram from a community-wide perspective.
To identify and describe the nonmonetary
benefits and costs of the flow reduction pro-
gram from a community-wide perspective.
2. Monetary Benefits and Costs of the
Flow Reduction Program
An evaluation ol the monetary benefits and
costs of the flow reduction program includes con-
sideration of three community entities'
The wastewater utility.
The water supply utility.
Water users.
Table 13 indicates the scope of these monetary
benefits and costs.
a Monetary Costs
Monetary costs of the llow reduction program
will consist of the direct costs of developing and
implementing the llow reduction program,
including.
Costs incurred by the wastewater utility lor
implementing llow reduction measures such
as purchasing and installing devices.
designing and printing public inlormation
material, or conducting in-residence water
audits.
Costs incurred by the water supply utility lor
implementing measures such as purchasing
and installing water meters, and reading and
maintaining the meters.
Extra costs incurred by water users, such as lor
individual purchase or installation ol devices,
(Note that these costs do not include any
changes in water or wastewater bills since
these changes will have already been
incorporated Jn the utilities' cost/cost-savings
determinations.)
The timing (i.e., year) ol these expenditures
should be estimated as accurately as possible
and attention paid to whether they are one-time-
only capital costs or recurring costs. The costs
incurred in each year should be expressed in
terms ol present worth. The sum ol these present
worth v^ues will yield the total present worth ol
the monetary costs ol the flow reduction program
to the community.
b. Mor iry Benefits
The monetary benefits ol the flow reduction
program will consist ol the total cost-savings
(expressed in terms ol present worth) to,
The wastewater utility due to net reductions
in capital and operation and maintenance
(O & M) costs resulting Irom decreased waste-
water flows.
The water supply utility due to net reductions
in capital, and O & M costs resulting from
decreased water demand
Water users, due to decreased energy costs
resulting from hot water savings.
Benefits to these three community entities are
discussed in the following subsections.
1) Cost Savings to the Wastewater Utility
a) Savings in Capital Costs. Reductions in
wastewater flows may alter the sizing and/or
staging ol specific construction efforts in develop-
ing a community's wastewater treatment facilities.
Certain process units are designed according to
hydraulic loading (the rate ol wastewater flow to
the treatment plant) while others are designed
according to organic loading (the concentration
ol wastes in the influent). The unit processes sized
hydraulically have the primary potential lor
being sized smaller due to flow reduction Since
the amount ol organic material entering the
plant will not change (barring increased solids
deposition in sewer pipes due to reduced flows),
the capacity ol the solids-handling equipment
such as aeration tanks and digesters, will remain
the same,
In a typical activated sludge wastewater
treatment lacility, the process units that potentially
can be sized smaller as a result ol flow reduction
constitute approximately 4O percent ol the
facility's total capital costs (Davis and Bursztynsky.
198O). These units include.
headworks (Le., receiving wells, lilt pumps.
screens, grit-removal chambers))
primary and secondary clariliers
effluent chlorination facilities,
effluent outfall.
In addition to these potential savings In waste-
-------
Costs of Flow
Reduction Program
Benefits (Cost Savings)
of Flow Reduction
Program
Wastewater Utility
Capital
O&M
Water Supply Utility
Capital
O&M
Water Users
Costs directly tied to program
(e g. purchase and Installation of
devices, public Information program).
Costs directly tied to program
(e g., meter purchase and Installatioa
meter reading).
Additional costs such as Individual
purchase and Installation of devices.
Smaller or delayed expansion of
capacity. Lower costs of pumping.
chemicals, labor, and the like
Smaller or delayed expansion of
capacity Lower costs of pumping
chemicals, and the like
Lower energy bills from less use of hot
water.
"The discount rate to be used throughout the analysis Is that set by the Water Resources Council for water-related projects
table 13. Scop* Ol Community-Wide Monetary Benefits And Costs (Present Worth*)
water treatment capital costs, capital cost savings
may also result Irom the ability to size the waste-
water collection system smaller. Sewer design
flow is directly proportional to average dry
weather flow which is similar to indoor water use
(Koyasako, 198O). Thus, reductions in indoor water
use proportionately reduce the sewer design flow
and allow sewer pipes to be sized smaller.
Reduced wastewater flows may cause
problems in the collection system, however,
which will partially offset these cost savings. Solids
may settle out and accumulate in the sewer lines
and anaerobic decomposition may begin to take
place, resulting in the production of methane and
hydrogen sulfide gases. Along with significant
odor problems, these gases may cause corrosion
of sewer pipes (DeZellar and Maier, 198O). These
problems have been mitigated in existing
collection systems by adding chlorine dioxide.
hydrogen peroxide, or by cleaning the sewer
lines more frequently (Koyasako, 198O). To avoid
these problems in new collection systems where
long-term flow reduction is expected, sewer pipes
may need to be designed with greater slopes to
maintain an adequate scouring velocity (DeZellar
and Maier, 198O). Where these effects occur or
must be planned lor, they will reduce the O & M
and capital cost savings related to the waste-
water collection system
The capacity requirements of these treatment
unit processes and collection systems are
determined by peak-day wastewater flows. Thus,
determining the capital cost savings to the waste-
water utility involves first estimating how the Cow
reduction program will alter the peak-day flow
projections made for the without-llow-reduction
condition. The effect of these reduced peak-day
flows on the sizing and staging of the
hydraulically determined wastewater treatment
and collection facilities is then estimated. There
are Jour possible outcomes of this analysis:
Neither the sizing nor staging requirements
change as a result of the program.
A new staging period is used, but the sizing of
the proposed facility and expansions remains
the same.
The sizing of the proposed facility and
expansions is reduced, but the staging period
remains the same.
Both a new staging period is used and the
sizing of the facility and expansions change.
The three possible sizing/staging changes result-
ing Irom the flow reduction program are
depicted in Figure 9. This figure can be used
along with Figure 8 (page 26) to display the
results of comparing the with- and without-llow-
reduction conditions. (In this and subsequent
diagrams, discussions and examples, it is to be
understood that decreased capacity require-
ments or smaller sizing of facilities due to flow
reduction refers only to those unit processes
which are sized according to hydraulic flow.)
Note that there are several ways to
accommodate the with-flow-reduction condition
For example, rather than planning for two
expansions, each somewhat smaller in size than
under the without-flow-reduction conditioa the
first expansion may increase capacity sufficiently
to eliminate the need for the second expansion.
All sizing/staging options should be considered in
light of Section 8e of the,Cost-Effectiveness
Guidelines.
Because flow reduction decreases only the
rate of wastewater flow and not organic loading.
it generally causes wastewater influent to be of
44
-------
higher solids concentration. The efficiency of the
treatment plant may therefore need to be
improved ii effluent cruality is to be maintained
under conditions of flow reduction It is possible
therefore that some of the biological treatment
units may need to be modified to maintain plant
efficiency. The analysis of capital cost saving
must consider the effects of flow reduction on the
sizing and staging of each unit process.
The present worth of the capital and
associated construction interest costs should be
calculated for both the with- and without-flow-
reduction conditions. The difference between
these two values is the present worth of the
capital cost savings to the wastewater utility. An
alternative and perhaps easier way to proceed is
to estimate only the difference in capital costs,
determine the difference in associated interest
costs, and then convert these cost differences to
present worth. The sum of these present worth
capital (and interest) cost differences gives the
total capital cost savings.
b) Savings in Fixed O & M Costs. Reductions
in fixed O & M costs due to lower capacity also
will result from the flow reduction program. For
example, fewer employees may be needed as a
result of delayed expansion or smaller facility
size. The total present worth of the fixed O & M
costs incurred throughout the planning period
should be calculated for both the with- and
without-flow-reduction conditions. The difference1
between these two values is the present worth of
the fixed O & M cost savings to the wastewater
utility. Again, in some instances it may be
possible to determine these cost savings by
estimating only the difference in fixed O & M costs
over the planning period between the with- and
without-conditions rather than estimating the costs
for each condition separately.
c) Savings in Variable O & M Costs. Reduc-
tion in average flow to the wastewater facility
due to the flow reduction program may alter
variable O & M costs. The direction and
magnitude of these costs will vary depending
upon the particular characteristics of the waste-
water treatment plant, the collection system and
the wastewater flow itself. In an analysis of the
effect of flow reduction on the variable O & M
costs of nine treatment facilities in California
Koyasako (198O) found that the percent change
in these costs from a "normal" flow year to years
with significant flow reduction ranged from a 5
percent decrease to about a 4 percent increase.
Energy and chemicals were the O & M cost
categories most affected by flow reduction, with
energy costs generally decreasing and chemical
costs either increasing or decreasing. Since
A flow reduction program can
delay facility expansion.
Capacity
^» without program
» with program
Peak (lows
_» without program
... with program
years
reduce the size of facility expansion.
or both.
Figure 9. Possible Slilng/Stagrlng Changes As A Result Ot
now Reduction Piogimu
-------
Without-Flow-Reduction Conditions
o Existing capacity ol facility I mgd
» Capacity ol proposed lacility years 0-10 3 mgd.
years 11-20 6 mgd years 2!-n 9 mgd.
a Protected peak-day How through plant increases linearly
from 1 mgd to 3 mc,d Irom year I to 11 and trom 3 mgd to
6 mgd Irom year M IT 21
Salvage value al end ol 20 years 0
B Initial cost ol facility S4 000 000
n Construction period interest associated with initial construction
SM 7.500
B Cost ol lirst expansion (construction begins in year 10) to
6 mgd capacity S3 250000
s Construction period interest associated with tirst expansion
S119844
n Cost ol second expansion (construction begins in year 20) to
9 mgd capacity S3 500 000
o Construction period interest associated with second expansion
S129 063
o Operation and maintenance costs
- Fixed annual O & M cost years 1 10 S168 000
- Variable annual O & M cost years 1-10 increases linearly
Irom 0-S60 000 in year 10
- Fixed annual O & M cost years 11-20 S340750
- Variable annual O& M cost years 11-20 increases linearly
Irom 0 S60 000 in year 20
- Interest rate 7% percent
Wlth-Flow-Reductlon Conditions
B Existing capacity ol tacility 1 mgd
B Capacity ol proposed lacility years 0-10 2 5 mgd.
years 11-20 5 mgd years 2l-n 7 mgd.
B Proiecled peak-day Mow through plant increases linearly
Irom 1 mgd to 2 5 mgd Irom year I to 11 and trom 2 5 mgd
to 5 mgd Irom year II to 21
B Salvage value at end ol 20 years 0
Initial cost ol facility S3 600 000
B Construction penod interest associated with initial construction
S132 750
B Cost ol tirsl expansion'(construction begins in year 10) to
5 mgd capacity S2 925 000
B Construction period interest associated wiih tirst expansicn
SI 07859
B Cost ol second expansion (construction begins in year 20> to
7 mgd capacity S3 150000
B Construction penod interest ^associated with second ex-ranson
SI 16 156
o Operation and maintenance costs
- fixed annual O& M cost years I-10 SlbOOOO
- Variable annual O& M cost years 1-10 increases linearly
Irom 0-S55000 in year 10
- Fixed annual O& M cost years 11-20 S310000
- Variable annual O & M cost years 11-20 increases linearly
Irom 0-S55 000 in year 20
- Interest rate 7^ percent
"table 14 Assumptions Used Ib Develop Hypothetical Example Ol Cost Savings To A Wastewater Treatment Facility
energy and chemical costs comprise a relatively
small percentage ol the total O& M costs, even
substantial changes in these costs will alter total
O & M costs only slightly Koyasako's analysis also
shows that O & M costs associated with the waste-
water collection system are likely to decrease
slightly as a result ol f'.ow reduction
To determine the variable O & M cost savings
o Estimate the effect ot How reduction on the
quantity ol average daily wastewater How
over the planning period
a Determine the change in variable O & M
costs associated with this reduction in aver-
age daily How
o Calculate the present worth ol the difference
in variable O & M costs between the with-
and without-conditions for each year in the
planning period
a Sum these cost differences to obtain the total
present worth ol the variable cost savings to
the wastewater utility,
The total present worth ol the cost savings to the
waslewater utility will equal the sum o! the
(present worlh) savings in capital costs, fixed O &
M costs and variable O & M costs
d) Hypothetical Example Showing
Calculation ol Cost Servings (Monetary Benefits)
to a Wastewcrter Treatment Facility. A simplified.
hypothetical situation is described to show how
one can go about calculating the savings to a
wastewater treatment facility resulting from a
flow reduction program Modifications in the
procedure most likely will be necessary in order
to accommodate specific circumstances
Assumptions used in this example are depicted in
Table 14, and the capacity versus time and
staging requirements lor these hypothetical with-
and without-flow-reduction conditions are
displayed in Figure 1O Calculations used to
estimate the present worth cost savings
associated with the foregoing assumed conditions
are demonstrated in Table 15 The total present
worth of the cost savings (monetary benelits) to
the wastewater treatment utility due to the
hypothetical flow reduction program is found to
be S94O.O99
2) Cost Savings to the Water Supply Utility
By encouraging reductions in water use. a How
reduction program will decrease the amounl 01
water thai needs to be supplied to a given pop
ulation As was previously described for the
wastewater facility, reductions in peak demand
will decrease the capacity requirements for watei
supply over the planning period causing
reductions in associated capital, interest and fixed
O & M costs, reductions In average daily use will
similarly decrease variable O & M costs
-------
First expansion
without flow reduction
with flow reduction
I
Capacity of proposed facility
Without flow reduction
Second expansion
without now reduction
w«h now reduction
I Protected peak day flow
1 without now reduction
I
with flow reduction
10
20 vears
riaure 10 With- and Wlthout-Flotr-Boductton Conditions for Hypothetical Wastewater Faculty
A procedure almost identical to that
described lor a hypothetical wastewater facility
can be used tor calculating the cost savings
(monetary benelits) to a water supply utility To
prevent omitting any potential cost savings, a
breakdown ol water supply lunclions into
categories similar to the tollowing may be uselul
" Administration (e g. management ol
personnel, accounting, meter reading)
" Acquisition (securing the water, storing it and
transternng it to the treatment facility)
Treatment (purifying the water)
o Transmission and distribution (all activities
(allowing treatment associated with supplying
water to the service area)
Clearly, the appropriate categorization ol
(unctions will depend upon the nature ol the
water supply For each category ol water supply
(unctions, a determination o! cost savings Irom the
(low reduction program should be made Using
tho treatment category as an example
a Determine how estimated reductions in peak
demand altect the treatment capacity
requirements over the planning period A
diagram showing the sizing /staging
characteristics tor the with- and without-
llow-reduction conditions can be developed
to graphically depict this comparison As with
the wastewater facility, various combinations
ot sizing/staging changes lor the water supply
utility may result Figure 11 portrays a with-
How-reduction condition which dillers in both
sizing and staging from the without condition
lor a water supply treatment tacility
Calculate the present worth ol the capital
cost savings resulting Irom the smaller
capacity
Calculate the present worth ol the fixed O &
M cost savings resulting Irom the smaller
capacity
Determine how the projected reductions in
average daily demand (le. average daily
production and supply) allect the variable O
& M costs (eg. chemical costs)
Calculate the present worth ol these variable
O & M cost savings
Sum the present worth values lor the capital
and interest cost savings, luced O & M cost
savings, and variable O & M cost savings to
obtain total cost savings (expressed in present
«7
-------
1 Calculate the present worth ol the capital cost savings
(including savings in construction period interest)
B Intitial (year 0) construction and interest costs
Without How reduction = 54147500
With tlow reduction = S3 732 750
Cost savings =S 414750
Present worth ol cost savings - S 414750
a First expansion (year 10) construction and interest costs
Without How reduction - S3 369 fM4
With How reduction =53032859
Cost savings = S 336^35
Present worth ol cost savings = S 165417
a Second expansion (year 20) construction and interest costs
Without How reduction = S3 629063
With How reduction = S3 266 156
Cost savings = S 362 P07
Present worth ol cost savings = S 87 444
a Total present worth ot capital cost savings = S 667 611
2 Calculate the present worth ol the fixed O ft M cost
savings
B Fixed annual O & M costs years 1-10
Without How reduction "S168000
With Mow reduction = SI50000
Annual cost savings = S 18000
Present worth ol annual
cost savings = SI33 424
a Fixed annual O & M costs years-11 -20
Without How reduction = S340 750
With How reduction =5310000
Annual cost savings = S 30750
Present worth ol annual
cost savings = SI I 1 888
ts Total present worth ol
lixed O & M cost savings
S245312
3 Calculate the present worth ol the variable O 81 M cost
savings
o Variable annual O& M costs years ! 10
Without How reduction increase linearly
trom 0 to S60 000 or by S6 000 per year
With How reduction increase unearly Irom
0 to S55000 or by 55 500 per year
Annual cost savings increase linearly Irom
0 to S5 000 or by S500 per yoar: i e cost
savings in year I = S500 cost savings in
year 2 = SI 000 ' etc )
Present worth ot annual cost savi-gs
= 518228
B Variable annual O & M cost; years !l 2J
Without How reduction increase linearly
trom 0 to 560000 or by S6 000 per year
With How reduction increase linearly Irom
0 to 555 000 or by 55 500 per year
Annual cost savings increase linearly trom
0 to 55,000 or by S500 per year (i e cost
saving j in year 11 = 3500 cost savings in
year 12 = SI 000 etc)
Present worth ot annual cost savinas
= 58 084
Total present worth ot variable O & M cost savings = S27 |7e>
4 Sum the total present worth values lor the capital and
Interest cost savings, the fixed O fc M cost savings and the
variable O & M cost savings to determine the total present
worth of cost savings tor the wastewatei utility due to the
hypothetical flow reduction program
S667 6114- S245 3 1 2 + 527
$040 OW
Ttablo 15 Calculations For Hypothetical Example Ol Cost Savings Tb A Wastewatei Treatment Facility
worm) tor the trealment category
Following the same procedure, the cost sav-
ings lor the other water supply (unction categories
should be calculated The sum ol the present
worth cost savings lor each category will ecrual
the total cost savings (expressed in present worth)
to the water supply utility Irom the How reduction
program
3) Cost Savings to Water Users As with the
monetary costs, the cost savings to water users
Irom a How reduction program are those which
a?e additional to the cost savings already
calculated for the water supply and wastewater
utilities. (Note that throughout the analysis, care
should be taken to avoid double counting) Sav
ings in water and wastewatei costs to water users
have already been incorporated into the savings
in capital and O & M costs calculated lor the two
utilities The most obvious remaining cost saving
to water users Is the saving in energy costs result
ing Irom less use ol hot water
To estimate the present worth ol the water
users' cost savings (monetary benefits), determine
the present worth ol the cost savings estimated loi
each year in the planning period and sum these
values to get the total cost savings-expressed in
present worth Care should be taken to ensure
that the timing of benefits is determined properly
and adjustments made accordingly For example
il plumbing code changes which require
installation ol low-flow shower heads in new con
struction are part of the program, significant bene
fits trom this measure may only begin to be
realized 5-15 years in the future
The EPA's Cost-EHectiveness Guidelines
stipulate that no inflation of wages and prices
should be allowed except lor land and energy
At the grantee's optioa energy prices may be
escalated using the EPA's published energy cost
escalation factors developed tor each region and
energy source (U S. EPA, Proposed regulatioa
November 3.198O) Thus, in calculating energy
related dollar savings from the How reduction
-------
r
F
Proposed tieotmenl expansion
without conservation
Existing Capacity
Peak day water demand
without conservation
with conservation
I
10
20 years
Figure 11 Suing And Staging Ot Water Utility Treatment Facility With And Without Flaw Reduction Measures
progiam. this price inflation may be taken into
account The eflect will be to increase water
user's monetary benelits over time The (allowing
example shows how to calculate these energy
cost savings
Under the assumptions stated and calcula-
tions shown in Appendix C. installing a plastic
orltice insert in each ot two showers in an
average tour-member household would be ex-
pected to save $12 O6 in energy costs in the lust
year in which they were installed To take the in
(lotion ot energy prices into account in determin
ing total energy cost savings over the planning
period. EPA's published tables ol Energy Cost
Escalation Factors are used to determine the ap
plicable escalation factors These tables show, tor
example that the escalation factor lor natural gas
in Region II is 35 percent for the 198O-1WO period
and an additional 1 percent lor the 199O-2OOO
period In other wordr. if the price ol natural gas
in 198O was S1OO. the price in 199O and 2OOO
would be SI 35 and SI 36. respectively Using these
escalation (actors, the present worth ol the total
energy cost savings over the planning period
may be calculated as shown in Table 16
This yields the estimated present worth of
energy cost savings resulting from the hot water
savings attributed to Installation ol plastic shower
inserts (S75O.OOO) Similar calculations would be
made lor expected energy savings Irom other hot
water saving aspec the How reduction program
The sum ol all these cost savings will equal the
total (present worth) energy cost savings at the
water user level resulting trom the program
c. Determination ol Net Monetary Benelits
Using results obtained so lar. total mone'ary
costs and benefits (cost savings) to the community
can now be summarized and the net monetary
benefits (total monetary benefits minus total
monetary costs) determined by completing a
table such as Table 17
3. Nonmonetary Benefits and Costs ol
a Flow Reduction Progrcmn
Nonmonetary benefits and costs derive from
the unquantiliable but nonetheless significant en
vironmental, social, economic, political and in
stitutional effects ol a flow reduction program In-
formation needed to asses.-, these costs and
benefits will be soecilic to a. -\ community
Much ol the relevant inlormc. >. 1 already
be available from the Envuoi j- : itorrnation
Document required in the taalit:: pla.mmg pro-
cess Other nonmonetary costs and benefits can
be qualitatively assessed from information provid-
ed under Step C (i e. first-cut program) and from
information acquired from p'iblic input into the
facilities planning process
-------
Information given
o Inili'i! yeur e:wcry cost savinas - SI 2 06
B 1-reruy sourc0 :s natural anr>
Gooaraphic area is Regicn II
o F.sralaton tnctors are 35 and 36 IT- ihe periods "580 1990
andl99o;>000 resoective'y
o Inleresl rale is '^ percent
B Plnnninq penod is 20 years
B F.PSPWF. = Equal Payment Series Present Wonh Factor tor
20 yen r* Giver> 7v, percent interest EPSPWF . = 10 W>
"UG3F" = Unilorm Gradient Series Factor lor 10 years
Given ?v percent interest UGSK = 39|S
a FPSPWF = Equal Payment Series Present Wonh Factor tor
10 years Given 7V« percent interest EPSPWF -. = 6903
PWFGS = Present Worth Factor ol a Gradient Series lor
10 years Equivalent to ,'UGSF ,) X fEPSPWF ,,) =-- 7.."04
SPPWF , = Single Payment Present Worth Factor lor 10
years Given 7vB careen! interest SPPWF, = 4909
o MPWF --- Modilied Present Worth Factor This is to
compute the present worth at the beginning "I the lirsl ten
years ol an equal payment series occurring during the
second ten years Equivalent to (FPSPWF -j X (SPPWF ) =
3.188
o MPWFGS , , =- Modilied Present Wonh Factor ol a
Gradient Series This is to compute the present worth at the
beginning ol the tirst ten years ol an unitorm gradient series
occurnna during the second ten years Equivalent to
(UGSF ) X (EPSPWF ,) X (SPPWF .) = 13277
To calculate ;^e present worth ol the total energy cost
savings
o Calculate the present wonh ol saving SI206 the initial
years savings each year lor the 20 year period I960 2000
S'?06 X 102^2 (EPSPWF,,) = 5124 12
o Calculate the present worth ot the average annual
increment in cost servings over the tirst 10 year perod
I960 1990
SI206 X 035 X 2704 (PWFGS, n) = 51141
o Calculate the present worth ol the additional cost savings
due to the initial energy price escalation (12 06 X 0 35)
which persists lor each year tor Ihe second 10-year period
1990-2000
S1206 X 035 X 3388 (MPW7,0 -,) = S1430
Calculate the present worth ot the average annual
ncrement in cost savings over the second 10-year period
1990-2000 due to Ihe second energy price esclation
SI206 X 001 X 13277 (M PWFGS.., 0) = 516
B Sum these tour present worth values to get Ihe total present
worth ol the energy cost savings over the 20 year planning
period
5124 12 + 1141 +14 30 + 16 = 314999
n Multiply this present worth cost savings by the number ol
residences estimated to install the shower inserts as a result
ol the (low reduction program For example il 5000
residences were expected to install the inserts Ihe
community-wide energy savings would be
SI4999 X 5000 = S749950
liable 16 Example Of Calculation Procedure 1b Allow For Energy Pries Inflation
Typical nonmonelary benefits and costs may
include
B Ettects on groundwater supplies (cost or
benefit)
m Ellects on multipurpose surlace water
reservoirs - especially lor recreational use
(cost or benetit)
B Eltects on lish and wildlife (cost or benefit)
o Grealer or lesser pollutant discharges entering
streams (cost or benefit)
a Odor problems due to more concentraled
wastewater flows (cost)
e Transaction effects (eg changing institutional
structures, altering public attitudes - cost or
benetit)
o Inconvenience costs (eg. possible public
dissatisfaction with flow reducing de" >:.
changes in lifestyle)
o Additional safety value or value of
alternative use gained from no longer
operating at the margin ol the available
water supply (benefit)
a Increased public satisfaction from water using
fixtures (eg. faucet aerators may reduce
splashing - benetit)
. a Others
Alter identifying all nonmonetary costs and
benefits, a qualitative assessment of then
magnitudes should be made Although these
positive and negative eflects cannot be neatly
summed as were the monetary costs and bene-
fits, they should be well integrated into the anal-
ysis At a minimum, those ellects ol critical
importance should be llagged so that important
differences between flow reduction program
alternatives can oe easily identified
A table similar to Table 18 may be a useful
organizing and integrating mechanism
4. Major Observations
o Additional detail on performing cost and cost
savings (monetary benefits) analyses is pro
vided in Appendix C
The nonmonetary costs and benefits should
not be translated into dollar values They
should be separately determined and their
relative importance subjectively evaluated
on the basis ol a community's goals and
characteristics
o It may be useful to describe the lull range ol
benefits and costs together in a set of figures
and tables with comments regarding their
perceived relative importance This could
serve as a mechanism lor succinctly
50
-------
I'loying results trom the technical analysis
1 as a local point lo: later communication
ii the public
jssessing the nonmonetary benefits and
s. consideration should be given to (low
uction program changes that would
pinate or reduce certain costs (disadvan-
laous etlects) or enhance certain benefits
vantageous eilects) This will be usetul in
rymg out Step E - deciding what modilica-
is may improve the tirst cut flow reduction
gram or what alternative program may
duce better results
Wasteworter Utility
Water Supply Utility
Water Users
Cos' Monetary Bereiits
Worh1 .'Present V/oih'
Total Monetary Total Monetary
Costs Benefits
(Cost Savings)
Net Monetary Benefits = To'ol Mone'nry Ben^ii
Total Monetary Co^ts
Table 17 Determining Net Monetary Benefits TO the
Community
Cost or
Ben^tn
Assessment o!
Maanitude ol Etlect
(low med hiah critical)
meed stream nunlily Iron re(1iiC'"'i! r«3lli]lnnl discharaes Beneli!
iced consumer surplus Irom dis^atistnction with shower head
ilit devire Cost
meed nronndwaler sunolios Irom reduced wntpr'domnnd Betielil
easPd odor duo lo more corirenlaled wnslfwoter Cost
oasod puolic knowledae 01 the community s water sunnlv
wnstowat^r eoridilions ' Beietn
Medium
'. nw
Hiati
Medium
Medium
am duality mioht b*5 either '""ihanced or deoroded
'"ridiria on th» stx^cilic rhanae r ollluenl q\iantitv
:utv T'd Us relationship to -trean How
18
Example Of A Qualitative Assessment Of Nonmonetary Costs And Benefits Of A How Reduction Program
-------
Step E.
HoveAU
Reasonable Alternatives
Been Considered?
It yes go to Step F.
If no go beck to Step C-2
-------
E. Hove All Reasonable Alternatives Been Considered?
1. Statement of Purpose
An initial evaluation of the first-cut flow reduc
tion program should be complete at this point
Step E is a pivotal step which asks the question
Have ah reasonable alternatives been
considered7 An "alternative" may consist of
minor modifications to the first-cut program or an
entirely new approach The objective is to ensure
that all potentially beneficial program
alternatives have been considered before
moving into the final selection process
2. Data and Information Needs
To respond to the question posed in this step.
the analyst need only focus oh the information
obtained thus far. along with his/her additional
perceptions about the community's water use
and wastewater characteristics
3. What To Do
Use the insight gained from evaluating the
fust-cut program, along with input received from
the water supply utility, other agencies/entities.
and any informal contacts made with the public
up to this point in the planning process to answer
the following two questions
o Can the program potentially be improved by
altering one or more of its components (le.
package of flow reduction measures, public
information plan, and implementation plan)9
o Can a potentially better program be
developed by essentially starting from scratch
and taking a whole new approach''
If the answer to either of these questions is
"yes", other alternatives should be formulated
and evaluated in the same manner as the first-
cut program Thus, a loop is made back to Step
C-2 and Steps C and D (program development
and cost/benefit analysis) are repeated lor
different alternatives The groundwork laid in
evaluating the first-cut program should make
these successive evaluations substantially easier
(Note thai one should keep making this loop
back to Step C-2 until all reasonable alternatives
have been considered)
4. Examples
a A Program Modification Is Indicated
Assume, for example, that the first-cut pro-
gram included provisions for voluntary retrofitting
of toilets and shower heads Insight gained from
the first-cut program evaluation may suggest that
greater benefits could be gained from distributing
and installing these devices free of charge The
flow reduction measures package from the first-
cut program should be reevaluated with this
modification in mind
b. A New Approach Is Indicated
Assume that the first-cut program does not
promote the amount of flow reduction required to
meet a utility's established target of postponing
wastewater facility expansion for the next ten
years In this case, a new approach needs to. be
identified and a new flow reduction program
synthesized Any or all of the three major pro-
gram components may need reconsideration to
develop a flow reduction program that is more
responsive to the situation at hand The
alternative^) resulting from this effort should then
be evaluated in the same manner as the lust-cut
program
5. Major Observations
It is tempting to glide over this step with a
quick "yes" to its central question Omitting con-
sideration of either a program modification or an
entirely new program may mean losing
substantial benefits by implementing a program
that does not take full advantage of opportunities
(eg. lor reduced water use with the attendant hot
water energy savings)
53
-------
A\
_*.....
B
.*...
C-l
.t.
D
L»:
r
y
StepF. Conduct Public Participation
Meeting (With Facilities
Planning)
Summarize the program alternatives considered
and the results ol the analysis.
Communicate findings to the public and obtain
public comments.
Make appropriate changes in program
alternatives.
Reassess both monetary and nonmonetary costs
and benefits based on public input and
subsequent to any changes made in programs.
-------
F. Conduct Public Participation Meeting
I. Statement oi Purpose
As has been repeatedly noted, securing the
cooperation of various community groups,
agencies, and knowledgeable individuals is
essential to effective How reduction program
planning and a basic requirement lor program
implementation Thus, identifying key groups and
individuals and establishing informal contact as
soon as possible, are recommended on the basis
ol pragmatic considerations A mode for formal
public participation in How reduction program
development and selection is also deemed
desirable Thus, Step F is included as a distinct
'element in this flow reduction analysis
methodology to underscore the importance ol
obtaining public input and also to guarantee that
(low reduction alternatives with their associated
costs and cost savings are brought to the
attention of the community at large
In view of-the above considerations, the
primary purpose ol this step is three-fold
a To describe to the public the key features ol
each alternative flow reduction program
being considered as these relate to a set ol
flow reduction measures, a public information
plan, and an implementation plan
To communicate to the public the findings
and results of the flow reduction analyses
including potential costs and cost savings to
the water supply and wastewater utilities and
to users of these services
° To obtain public comment on the alternative
flow reduction programs being considered
and on their associated program compon-
ents
2. Data and Information Needs
Two types of information needs pertain to this
step knowledge about the existing public par-
ticipation program lor facilities planning, and in-
formation needed to make the public meeting
mutually beneficial (le. to the public and to the
' facilities planners)
According to EPA regulations, public
participation programs lor facilities planning are
ol two types (US EPA. February 1979) Each differs
in the extent to which it may provide a ready
made vehicle lor public input into the How reduc
tion analysis
o Under the requirements lor the "Basic Public
Participation Program" - the type most com-
monly used - the grantee is required to
"consult" with the public early in the process
(before selection ol the alternatives to be
evaluated in the cost-elfe^nveness analysis).
and then hold a public information meeting
when alternatives have been largely
developed (le. and the cost-effectiveness
analysis performed) but before an alternative
or plan has been selected A public hearing
is also required prior to final adoption of the
facilities plan (US EPA. February 1979)
Depending upon the precise timing of the
public meetings, it may be possible to use the
one held early in the facilities planning pro-
cess as the vehicle for obtaining public input
into the latter stages of the How reduction
analysis II. however, the meeting is held after
the cost-eliectiveness analysis (ol which the
flow reduction analysis is a part) is complete
an earlier meeting will be necessary
a Under certain situations, the Regional
Administrator may order a "Full-Scale Public
Participation Program" lor facilities planning
In addition to the components of the basic
program, a lull-scale program requires the
hiring or designation ol a public participation
coordinator and establishment ol an advisory
committee An extra meeting to obtain public
input into the flow reduction analysis may or
may not be necessary when a lull-scale pro-
gram is in operation, depending upon the
membership interest, the level ol activity of
the advisory committee, the timetable of
meetings, and the like In either of the above
situations, it is desirable to take lull advan-
tage of public information activities already
planned and available under the public
participation program associated with lacil
ities planning Details ol such activities are
available in the "Public Participation Work
Plan" submitted to EPA within 45 days after
the date of acceptance ol a Step 1 grant
award (U S EPA. February, 1979)
The information to be presented al the public
meeting (or the flow reduction analysis
component of a facilities planning meeting) is
available from the flow reduction analysis This
information and data must be communicated
effectively lor the public to become informed and
lor useful public comments to be obtained Charts
figures, tables and other graphic displays that
translate the essence of the technical analysis
results should be designed to accompany the
presentation A concise, written summary of the
How reduction program alternatives and the
findings regarding each ol them should be
prepared for distribution at the meeting
The "Information Program lor Citizen Advisory
55
-------
Groups", developed by Pennsylvania Stale
University, may enhance these public involve-
ment activities The program consists of 18 informa-
tion units, including units on Water Conservation
and Reuse (Unit 8) and Cost-Effectiveness Analysis
(Unit. 1O), geared toward citizens and local
officials involved in water quality and waste-
water treatment planning EPA's regional offices or
individual state water pollution control agencies
can be contacted concerning this program
3. What To Do
The public meeting should locus on the fol-
lowing regarding the flow reduction analysis
o Presenting a clear description of the program
alternatives and the associated monetary
and nonmonetcry costs and benefits
a Seeking public comments on issues and
concerns which will help evaluate or predict
- The likelihood of public acceptance of spe-
cific flow reduction measures and the pro-
gram as a whole
- Ways to enhance the effectiveness of the
program
- Which public information measures are
likely to reach and be effective with tne most
people
- The ease or difficulty of program implemen
lotion
- Other issues of uncertainty
B Providing an opportunity lor open public
comment - that is, an opportunity for the pub-
lic participants to raise issues of concern to
them and to make comments and
suggestions.
After the meeting, make appropriate changes
in program alternatives based upon these public
comments Reassess both the monetary and
nonmonetary costs and benefits where their
initial evaluation has been affected by the pub-
lic's input and program changes
4. Example
Results of a public meeting may reveal that a
local institution, such as a university or hospital, is
willing to voluntarily undertake an all-out flow
reduction/water conservation campaign One or
more program alternatives can then be adjusted
to accommodate this adduional feature For
example, the institution may be willing to install
water saving retrofit devices in all toilets and
shower heads provided that the utility supply the
devices In such a case, appropriate adjustments
in flow projections, direct program costs and cost
savings must be made
5. Major Observations
The example provided above highlights a
key feature of the approach mentioned earlier in
this document The flow reduction analysis
involves an iterative process Changes are
constantly made as new information and insight
is obtained Only in this way can an effective
and broadly acceptable program lor the commu
nity be synthesized, receive public support, and
ultimately be implemented.
Reasonable costs of public participation as
identified in the "Public Participation Work
Plan" lor Step 1, or as otherwise approved by
EPA, are grant eligible (U S EPA February
1979)
o Public participation in Step 2 (design) and
Step 3 (construction) is also grant eligible pro-
vided that it is included in an EPA-approved
work plan for such activities (U S EPA,
February 1979) This is important to keep in
mind in contemplating how public
participation may be used as a vehicle lor
continuing public support ol a flow reduction
program. It may even be a key part of the
public information component of the selected
program
-------
StepG.
Select A
How Reduction
Program
Develop selection criteria.
Display impacts ol attractive alternatives.
Involve appropriate authorities in final selection.
-------
G. Select a Flow Reduction Program
1. Statement of Purpose
The intent of this step is to suggest a general
Iramework lor selecting the final How reduction
program It stresses full consideration of all ellects
pertaining to each alternative program so that a
judgment inclusive ot all available information
will be made
2. Data and Information Needs
Selecting the final How reduction program
requires
Criteria appropriate tor the screening of
alternatives and selection of the final pro-
gram Although these criteria will vary
depending on a particular community's
circumstances, they must incorporate the
features required in the EPA's Cost-Effective-
ness Guidelines for the recommended pro-
gram - that is, the recommended program
must comprise How reduction measures
which are cost-effective, supported by the
public, and within the implementation
authority of the grantee or another entity
willing to cooperate with the grantee
o A description of the major findings and
results of the evaluation ol each attractive
How reduction program alternative The
scope ol this information is a matter of
subjective judgment, but should be sufficient
lor weighing the relative merits ol each
alternative
3. What To Do
Once the selection criteria are made explicit
and the information needed to weigh the
alternatives is synthesized, a recommended pro-
gram from among the available alternatives
must be selected The two cases described below
suggest a framework lor program selection
appropriate lor communities with two different
goal orientations
« Case L A community has set a specific target
at the outset ol the How reduction analysis to
either reduce wastewater Hows a given
amount by a certain time, or to hold flows at
or below a specified level over a specified
period of time This approach could be
motivated by the need to avoid capacity
overloads which would otherwise occur at
some point during the several years ol con-
struction needed lor a maior facility The fol-
lowing steps leading to program selection
would be appropriate for such a community
- Screen out any alternatives which, upon
final analysis, appear unlikely to prove ellec
live in meeting the staled target Note thai
eliminating an alternative for this reason,
especially when it offers greater net benefits
than an alternative not eliminated, can only
be justified if this target absolutely must be
met lor some critical reason (eg, resulting
capacity overloads would violate permit
requirements)
- From among those alternatives remaining,
select as the recommended program one for
which the net monetary benefits are positive
Generally, try to maximize net benefits provu
ed that a qualitative assessment of the non-
monetary costs and benefits (including publn
support and implementation considerations))
does not point to selection ol a different alter
native
o Case 2; No specific target lor reduced Hows
has been established for the program other
than to denve the maximum benefits ob-
tainable An appropriate approach lor a
community fitting this situation would be the;
following'
- Select that alternative lor which the net
monetary benefits are a maximum, provide^
that a qualitative assessment ol the non-
monetary costs and benefits (including publ)
support and implementation considerations
does not point to selection ol a different alte
native
The broad framework lor selection is thus to
maximize net benefits (i.e., cost savings) allowm<
lor the possibility that nonmonetary effects may
be overriding
Organizing data along the lines ol Table 19
may be useful in making this final progam sele1
tion.
4. Major Observations
Clearly, where the authority to implement tl
measures included in a program alternativ
is either lacking or insufficient, and there a;
pears to be little hope ol obtaining the
necessary authority, this alternative should
eliminated. This is a key implementation is
which should have been acted upon earln
» The final selection of the recommended pi
gram cannot be other than subjective due
the qualitative nature and potential impor
lance ol the nonmonetary costs and bene
Nevertheless, this selection should be base
upon full consideration and knowledge ol
complete array ol benefits and costs
-------
Present Worth Important Important
ol Net Monetary Nonmonetary Nonmonetary Public Ability to Other
Benefits Costs Benetits Support Implement Comments
Alternative 1
Alternative 2
Alternative 3
Alternative 4
Alternative 5
Recommended Flow Reduction Program: Alternative.
"table 19. Organisation Ol Data For Final Program Selection
associated with each alternative.
60
-------
-------
Incorporate Row Reduction Program into4 Facilities Plan
- Statement of Purpose V " *
The purpose of this lined step is to integrate n
e selected flow reduction program and its
nticipated effects with the other aspects ol lacil-"
es planning and to document results ol the flow
'duction analysis. " j>; - ^ ', ,"
Data and Information Needs
'All ol the information heeded lor this step has
Iher been obtained as part ol the analysis or is
vcdlable from the rest ol the facilities planning
recess. « >u ''"".
What To Do
Based on the Dow reduction program
lected and the projected wastewater flows (or
ls "with flow reduction" conditioa final adjust- ,
ients are made in the sizing or staging of the - -
tcility corresponding to the altered projections.
\e appropriate adjustments should already ' b
ave been determined In order to perform the , ;
3$t savings analysis lor that program alternative.
Finally, document In the facilities plan. * ^
An estimate ol the costs ol the proposed flow;
reduction measures over a 20-year planning
period.
An estimate ol energy reductions, total cost
savings lor wastewater treatment water sup-
s ply and energy use.'and the net cost savings/
'" Irom the proposed flow reduction measures/,*;
' over the planning period.
1 Provisions lor lmplementing"the"p'r6po'sed-v;T '
i flow reduction program including a publicj
M_ information program.Xf"" "" " """
" A commitment that the flow reduction pro
< gram will be carried out as stated if * "J
adjustments are made to a facilities planT^N
' based on projected water savings (Yeoman, w-
198O> Appendix A to the handbook provides?
additioncUinIormcrUon"ontthevdocumentationx5
jequired, ^ """" ' '"
4. Major Observations
, As emphasized earlier, the" flow reductionv»Vl-
analysis is one ol three tasks undertaken to refine f
wastewater flow projections and treatment plant
capacity needs. The results of the analysis will not
call lor fundamental alterations In the type of *; -
facility being planned, but rather lor marginal 1,
changes In the sizing or staging ol certain ol the""
facility's unit processes. Thus, incorporating the:
flow reduction analysis results into the facilities';
plan near the end ol the planning process will
not affect the schedule or timing of subsequent,
construction grant program'eflorts. < ""
-------
References
_
1 ' r< " , \v
Boumana Duone D» John J Bolond. and John R'-tt
Sims. 198O The Evaluation of Water Conserve- ^"m
tion for Municipal and Industrial Water Supply V
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Engineer Institute lor Water Resources by Planning
Management Consultants. Ltd. Contract No. ,K * ' 'J
Bishop. Walter J 1975. "Field Experiences in Water '
Saving Programs ol the Washington Suburban *,"
Sanitary Commissioa" In Proceedings - v " r ' «*
Conference on Water Conservation and > *
Sewage Flow Reduction with Water Saving ' '
Devices. Institute lor Research on Land and Water
Resources, The Pennsylvania State University.
University Park. Pennsylvania «' » ',;,.*. -V< -<
California Department ol Water Resources (DWR).' *
May 1976. Water Conservation in California, ,
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California Department ol Water Resources (DWR).,«
197& A Pilot Water Conservation Program - Final
Report Bulletin 191 (Includes Appendices AH , ,
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California Department ol Water Resources (DWR>
1979. "22 Months Later The Oak Park Retrofit Pro- ,
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California * , ,^
Call Harrtsoa Jr 1978. "The Interrelationships *.
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Association of Counties Research. Inc 1978. v,"
Camp Dresser and McKee. Inc 198O Guidelines
for Water Reuse US. Environmental Protection
Agency. Contract No68-O3-2686. Washingtoa DC
M ' . 'V« , " V* 'j <" ' > J ; ,">* f f
Church, Richard W. October 15.198O. Personal
Communlcatloa Executive Director. Plumbing
Manufacturers Institute. Glen Ellya Illinois. , ,
Citizens Advisory Committee. Washington ,
Suburban Sanitation Commissioa 1977. "How to
Decrease the Demand lor Water Through ' ^
Changes in the Rate Structure." Reprinted in-fi, -
Readings in Water Conservation Ronnie 4.,
McGhee, et aU eds. National Association of,, .
Counties^Research, Inc 1978. ,, /, /,'* i '* "' . T
Cole. Charles A. 1975. "Impact ol Home Water Sav-
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Water Conservation and Sewage Flow Reduc-
tion with Water Saving Devices. Institute (or
Research on Land and Water Resources. The ,.
' Pennsylvania
Pennsylvania^;
Conklinl GF arid PW Lewis. 198O Evaluation of *>,
Infiltration/Inflow Program. Final Report (Draft). T
US. EPA. Project No. 68-OM913. Washingtoa D Cy #
Consumer Reports (Staff). 1978.l"Water. Time Tb Start
Saving?', Consumer Reports 43 (5>294-3O2 and 43
<\c^\.c\n-f\n <"',."^ "*.r\u>/'i*"i*-} i /.i*.*t,f- >. , f"
\l\J/*J/&\Jt/., t.i^l3Ji«\%i.y>'il, *i ''jVt.vjx/i*-*^ « ^>
Davis, John A, and Taras A Bursztynsky 198O. -, >\
"Effects ol ol Water Conservation on Municipal X'~.
Wastewater Treatment Facilities", Journal WPCF. '<
DeArment Wallace E1975. "Impact ol Conservai-
tion on Water Industry." in Proceedings - » -1 ?-? ''
Conference on Water Conservation and v ' ^
Sewage Flow Reduction with Water Saving =.
Devices. Institute for Research on Land and Water
Resources. The Pennsylvania Statet University.
University Park. Pennsylvania ,i-«.Jl '. ; i^ ' 1
\ f > "W -!*i"'kt * ' (
Dellne, M. ed October 1978. Water Conservation >\
in Municipally Supplied Areas. Great Lakes
Basin Water Conservation Plan - Revised Draft
Ann Arbor. MlcWgon^,;?;*,,*^',., -', \, /;' "^
DeZeller.' Jeffrey T and Walter J Maier 198O * -
"Effects ol Water Conservation on Sanitary Sewers
and Wastewater Treatment Plants" Journal WPCF.
Vol5ZNo LJanuary 198O. * 4 -u,.\^fn .*V-
Fair, Gordon Maskew 8c John Charles Geyer 1954,
Water Supply and Waste-Water Disposal John
Wiley and Sons. Inc. New York. New York. % ,> v
Feldmaa Stephea 1977 A Handbook of Water -
Conservation Devices. Graduate School of ~..
Geography. Clark University. Worcester. ' ; r..
Massachusetts ' - _
Flack. Emest J, Wade P. Weakley. and Duane W.
HllL 1977. Achieving Urban Water Conservation.
A Handbook. Colorado Water Resources <\~->- - i'
Research Institute. Colorado State University. Fort .
Collins, Colorado^ ?,, ^y, ;<,>>, x \ >^'f* ^ '
Fultoa Nell R. 197a "Elmhurst Water Conservation
Program" in Proceedings. National Conference
on Water Conservation Municipal Wastewater
Flow Reduction - November 28-29,1978.., ' '
Chicago, Illinois. US. ERA. Office of Water Program
,' Operations.; "£;> , ; ^\, ^^> ,v ,? ^ _.., t
Fultoa Nell R. August 198O. Personbd J r V \a -,
Communlcatloa Chlet Bureau ol Resource ' ,-,-.
Management Division of Water Resources, Illinois
Department ol Transportation Formerly. Assistant
City Manager, City ol Dmhurstl A \v, v« A> ^
""^fr-^T-"^^ , , k
16 blank
?L- t-^'-J^ f «
-------
Greor. Michael James. 1975. "Residential Water
Conservatioa The Suburban Maryland 'r
Experience," in Proceedings Conference on a *'
Water Conservation and Sewage Flow Reduc-
tion with Water Saving Devices. Institute for -
Research on Land and Water Resources. The ^ "
Pennsylvania State University University Park, -
Pennsylvania'' j .^ v^ \> ? " %£ ' '- '*" /'" . -
Heath. Donald. September 198O Personal
Communicatioa California Department of Water -
Resources. Sacramento. Calilomia
Holland. M198O Personal Communicatioa'
California Water Resources Control Board
Sacramento. California
Hopp, Wallace Joha October 1979 Cost-Effective-
ness of Household Water Conservation in
Municipal Water Use Strategies. Center for >
Development Technoloy, Department of
Technology and Human Affairs, Washington
University Saint Louis. Missouri. <: > . "
Koyasako. Jimmy S198O Effects of Water Conser-
vation Induced Wastewater Flow Reduction! A
Perspective Prepared lor US EPA Wastewater ' '
Research Divisioa Cincinnati Ohio. A , > >. -1- .
Lottie, James. 1977 "Public Education lor .Water "
Conservatioa" Community Water Management
for the Drought and Beyond. A Handbook for >
Local Government The Governors'Office of **~
Emergency Services, State of Calilomia ^ '
McGany. Robert S1978. "Water and Sewer Conser
vation Oriented Rate Structure "Washington ' »~
Suburban Sanitary Commissioa Hyattsville. 'l' '*<. .<-.''*<< ,
Milne, Munay. March 1976. Residential Water Con-
servattoa California Water Resources Center. ' > t
Report No. 35. University ol Calilomia Davis,i ,'/' >
Calilomia' J w. »' «- v?;tjn. >.''i\'
Nelsoa John Clot Mcnch'1977. North Marin's Little,
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. ' Peil K. M and O S DiehL 1979 "Reducing Sewer-''
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v Rice. IM and L G Shaw 1978. "Water Conserve- .
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Schaeler. Richard K. 1975. "Sodoeconomic
" Considerations lor Domestic Water Conservatioa"
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' Saving Devices. Institute lor Research on Land
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Sharpe, William E1978. "Why'Consider Water Con
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Sharpe. W E and P W Fletcher July 1977 "The
Impact of Water Saving Device Installation Pro-
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Research on Land and Water Resources. The
Pennsylvania State University Research
Publication 9& University Park, Pennsylvania .
US. DOE 198O "The Low Cost/No Cost Energy Con
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Washingtoa DC '^-v */",< o i^
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Wastewater Treatment Works Construction Grants
Program (4O CFR Part 35, Subpart E> Federal
Register Washingtoa DC \ .'' , * v s .
US. EPA. February 16.1979 "State and Local "'
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the Municipal Wastewater Treatment Works Con-
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Clean Water Ad) Washingtoa D C ;c,. *\ u. 'j ;
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Construdion (regarding energy price inflation)/'
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, US-'EPA; 'January t979;Kftj^cipai Waste water.
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v! V
> Washington,, D.C Clem L Rastatter, ed^
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. AJUL.
, I-
-------
US. EPA. 1979 Wetter Supply - Wostewoter . Yeomoa Barbara (Office of Water and Waste
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Hyattsville. Maryland,
-------
V
Appendix A /
Sections 8b, c, and d of the Cost-Effectiveness Guidelines
for the Construction Grants Program;
b. Wastewater flow estimates.
0) In determining toted average daily flow lor
the design ol treatment works, the flows to be
considered include the average daily base flows
(ADBF) expected Irom residential sources. ,
commercial sources, institutional sources, and
industries the works will serve plus allowances lor
future industries and nonexcessive inliltra-. k
tion/inflow The amount of nonexcessive infiltra-
tion/inllow not included in the base flow
estimates presented hereia is to be determined
according to the Agency guidance lor sewer
syste ~*> evaluation or Agency policy on treatment
and control ol combined sewer overflows (PRM
75-34). *
(2) The estimation ol existing and luture ADBF.
exclusive ol flow reduction Irom combined resi
dentiaL commercial and institutional sources.
shall be based upon one ol the following meth-
ods!
(a) Preferred method. Existing ADBF is
estimated based upon a fully documented analy-
sis ol water use records adjusted lor consumption
and losses or on records ol wastewater flows lor
extended dry periods less estimated dry weather
infiltration Future flows lor the treatment works
design should be estimated by determining the
existing per capita flows based on existing
sewered resident population and multiplying this
figure by the luture projected population to be
served Seasonal population can be converted to
equivalent full time residents using the following
multipliers.
Day use visitor
Seasonal visitor
OltoO.2
O5toO8
The preferred method shall be used wherever
water supply records or wastewater flow data
exist Allowances for luture increases ol per
capita flow over time will not be approved
(b) Optioned method Where water supply
and wastewater flow data are lacking, existing
and future ADBF shall be estimated by multi-
plying a gallon per capita per day (gpcd) allow-
ance not exceeding those in the lollowing table,
except as noted below, by the estimated total of
the existing and luture resident populations to be
served The tabulated ADBF allowances, based
upon several studies of municipal water use.
Include estimates lor commercial and institutional
sources as well as residential sources. The
Regional Administrator may approve exceptions
to the tabulated allowances where large (more
than 25 percent ol total estimated ADBF)
commercial and institutional flows are
documented'
?
JGallons" ',*
- H.. . per capita,
[Description'1 v per day«;
' Non SMSA cities and towns < *>>
with projected total lO-year -
populations ol 5.OOO or less.:* '>' 6O to 7O
Other cities and towns. ! .:. 65 to 8O
c. Flow reduction.
The cost effectiveness analysis lor each -
facility planning area shall include an
evaluation ol the costs, cost savings, and effects ol
flow reduction measures unless the existing ADBF.
from the area is less than 7O gpcd or the current
population of the applicant municipality is under
1O.OOO. or the Regional Administrator exempts' '
the area lor having an effective existing flow '
reduction program. Flow reduction measures
include public educatioa pricing and regulatory
approaches or a combination of these In
preparing the facilities plan and included cost
effectiveness analysis, the grantee shall as a
minimum.
0) Estimate the flow reductions implement-
able and cost eflective when the treatment works
become operational and after 1O and 2O years ol
operatioa The measures to be evaluated shall
include a public information program; pricing
and regulatory approaches; installation ol water
meters, and retrofit ol toilet dams and low flow
shower heads lor existing homes and other
habitation; and specific changes in local
ordinances, building codes or plumbing codes
recruiring installations ol water saving devices
such as water meters, water conserving toilets.
shower heads, lavatory faucets, and appliances in
new homes, motels, hotels, institutions, and other
establishments.
(2) Estimate the costs ol the proposed flow
reduction measures over the 20-year planning
period including costs ol public inlormatioa
administration retrofit ol existing buildings and
the incremental costs. 11 any, ol installing water
conserving devices In new homes and
establishments.
(3) Estimate the energy reductions) total cost
savings lor wastewater treatment water supply
and energy uset and the net cost savings (total
savings minus total costs) attributable to the
proposed flow reduction measures over the plan-
' ning period The estimated cost savings shall -4
reflect reduced sizes ol proposed wastewater'
PrprpHinnr ?nm» hhnlr
-------
treatment works plus reduced costs ol luture
water supply facility expansions.
(4) Develop and provide for implementing a
recommended flow reduction program. This shall
include a public information program
highlighting effective flow reduction measures,
their costs, and the savings of water and costs for
a typical household and for the community In
addition, the recommended program shall i
comprise those flow reduction measures which
are cost effective, supported by the public and
within the implementation authority of the .
grantee or another entity willing to cooperate
with the grantee ,', ,, ^ J,
(5) Take into account in the design of the
treatment works the flow reduction estimated for
the recommended program. , ^
d. Industrial flows. * ;
(l)The treatment works' total design flow
capacity may include allowances lor industrial
flows The allowances may Include capacity
needed lor industrial flows which the existing
treatment works presently serves However, these
flows shall be carefully reviewed and means of
reducing them shall be considered. Letters of
-I *,'-,' '' f ..,<.» ' > , b - t
intent to the grantee are required to document
capacity needs for existing flows from significant
. 'Industrial users and lor future flows from all -
industries intending to increase their flows orvv *
' relocate in the area Recjuirements lor letters ol
- intent from significant industrial dischargers are
set forth in § 35 925-ll(c)(4O CFR Part 35) ^ t ,\
(2) While many uncertainties accompany' '
forecasting future industrial flows, there is still a '
need to allow for some unplanned future /» ^\ '
' industrial growth. Thus, the cost effective (grant '
eligible) design capacity and flow ol the treat- ^
ment works may include (in addition to the r ,'.
" existing industrial flows and future industrial flows
documented by letters ol intent) a nominal flow '
allowance lor tuture nonidentiliable industries or
for unplanned industrial expansions, provided "
that 2O8 plans, land use plans and zoning -
provide lor such industrial growth. This additional
allowance lor luture unplanned industrial flow
shall not exceed 5 percent (or 1O percent lor
towns with less than 1O.OOO population) ol the
total design flow ol the treatment works exclusive
ol the allowance or 25 percent ol the total .
industrial flow (existing plus documented future).
whichever is greater , s " . ,
I ' 'I > ' ' V A.
i '.'..' ' ( ' " V. '< -, ' J' . '
Source. US. EPA September 27, W7a 40CFR Part 35. Subpart E "Municipal Waslewater Treatment Woikk Construction Grants Program"'
Federal JMglitei VoL 41 No. 18& ' -
70
-------
Appendix B ,
Detailed Descriptions of Selected Flow Reduction Measures
t -* .. -' - - t.,...-». i
, This appendix supplements the discussion ol'
flow reduction measures provided under Step C
In Part n ot this document with more detailed ,.
descriptions ol specific individual measures that '
may be Included in a flow reduction program...'
Three types ol methods are discussed.; ' '
Structural methods - water saving devices
and appliances that can be Installed In new
and existing construction (see below).
Economic methods - common types ol water
rate structures and the relative extent to
which they encourage or discourage conser-
vation (page 79>
Legal methods - detailed descriptions and
examples ol code changes that have been
implemented (page 81> *
L Water Saving Devices and
Appliances
Use of more water efficient plumbing fixtures,
devices, and appliances is one ol the most
practical and effective ways to conserve water
The passive nature of water saving devices is one
attractive characteristic with a more efficient
faucet shower, or toilet the water user can be sav-
ing water without even thinVlng about it Many
devices are also economically attractive) the
water efficient models are often available lor
about the same cost as the conventional models.
Furthermore, conventional models already
Installed can often be made more efficient with
simple. Inexpensive retrofit devices.
With increasing attention being given to
water and energy conservatioa and with the
added Incentives ol natural limits to water
supplies and ever increasing costs for water.
wastewater, and energy services, water efficient
fixtures and devices have received substantial
attentloa Several publications have provided
intensive reviews ol the types, sources, and costs
ol water saving hardware available. Notable -
examples include , »
Milne, Murray. 1976. Residential Water Conserva-
tioa Report No. 35. California Water Resources
Center, University of California/Davis. '
Nelsoa J. CX1977. North Marin's Little
Compendium ot Water Saving Ideas. North
Martn County Water District. Novato; California
California (State of). Department of Water
Resources. 1978. A Pilot Water Conservation Pro-
gram Bulletin No. 191 (especially Appendices G
and H on Device Testing and Selection).,.
Sacramento, Calllomia' '
Consumers Reports (staff). 197& "Water! Time to
Start Saving?' Consumer Reports, 43(5> 294-3O2
and 430O) 572-577.,;> , ,>*.'. , .', <
> It Is important to recognize that rapid
changes are occurring in the water use
efficiencies and costs of relevant hardware. Over
the past several years, essentially all major '
plumbing and appliance manufacturers have ;
begun offering a complete 1'ne ol water saving
products indeed, some manufacturers have .
switched their product lines to such an extent that,
water efficient models are now the norm and *"-'
may even be less expensive than the old i.
"conventional" models. The changes are major
and are continuing Thus one Important aspect ol«
flow reduction analysis will be to make sure that.
available Information on hardware performance,
and cost Is up-to-date This will require selective
Inquiries to manufacturers and distributors In i
addition to utilization of the most current !
compilations ol available hardware inlormatioa
The following paragraphs briefly introduce
and summarize the status ol many devices and
appliances which may be of interest It Is
Intended that this be a starting point lor those
performing flow reduction analyses. This inlorma-'
tion should be used to develop more specific, up-
to date information in the context ol individual
analysis efforts. s , <
a Products for Installation in New Con*
(traction, Remodeling; and Replacement
* 1) Shower Heads. Conventional shower
heads are usually used at water delivery rates oi
approximately 5 to 6 gallons per minute
Maximum flow rates sometimes exceed 12 gpra
Several different types of low flow shower heads
are available which reduce the maximum '
possible flow rate to between O5 and 45 gpra
the average rate being approximately 25 gpm.
The Calllomia Department of Water Resources' %
(1978) recently conducted extensive tests with
conventional (control) and low flow, shower ;
heads. Figure B-l summarizes their results. Note'
the wide variability among maximum flow rates
lor conventional shower heads, in some cases v '
they obviously were designed with little concern
about using water efficiently. On the other hand.
the group of thirteen low flow shower heads '
tested Indicates that manufacturers are now
making available a selection of fixtures '-
1 incorporating more concern lor wise energy and
water use. Some states are now requiring that all *
shower heads sold have maximum flow rates (at
a specific pressure) below some standard value.
-------
Source California DWR, 1978 Bulletin 191. Appendix G. ,.
; , ,&*;. ~ l >v "'
'Y-"!*' '"'ConvenUonal/fS;'1'" V'V'
Typical
low llow
shower
head
Range lor 13 low flow
shower heads tested '
20 40 60 80
Water Pressure (pslg)
Figure B 1 Low Flow Shower Head* Comparison To
Conventional Models
usually about 3 gpm. In California, for example.
this requirement was adopted in 1977 ,
Most low flow shower heads incorporate a
flow restrictor and aerator In additioa some are
equipped with cut off valves which allow the
flow to be stopped temporarily while soaping
without altering the hot/cold water mixture at the
on/off valves. In addition to the water savings
Irom low flow shower head use, substantial ener t
ay savings result Irom less hot water being used.
Generally between 5O to 75 percent of shower
watei is hot water; the exact amount depends , , r
upon the distance between the shower and hot (
water heater, the amount of insulation on pipes
transporting hot water to the shower, the ambient
water temperature, the temperature setting of the,
hot water heater, and the user's habits. In
California the new shower head flow limit was
adopted as an energy conservation measure .
rather than as a water conservation measure.
Low flow shower heads are competitive In?
cost with conventional shower heads and many,
manufacturers' lines now feature low flow » .
models. Costs for both conventional and low flow'
models range from $4,OO for plastic models up to.
$20-OO lor metal alloy versions. Some low flow
* shower heads presently on the market do not\'%A-
satisfactorily reduce flows and maintain shower
quality It is suggested that particular devices be
. tested or the results of tests by other agencies be
reviewed before recommending specific brand
names or models. For example, tests have been
conducted and reported in Consumer Reports <
(May 1978) and by the California Department ol
Water Resources (1978> ^ '^' -\\f^ ,'|. v* (,^
, 2) Faucets. Conventional domestic faucets' --,
normally provide a maximum discharge of 4 to 5
gpm. Low flow faucets deliver a maximun flow ql
O 5 to 2 5 gpm depending on the flow control ' ',
type and specific design. They typically cost 5, *
^between 5 and 1O percent more than "'< --;'
conventional faucets (Nelsoa 1977). this usually *J
amounts to a difference of one to six dollars In'
addition to the water savings provided by these
faucets, the savings in energy lor heating hot ,
water are substantial The mechanisms by which
low flow faucets achieve water savings varyi*
Flow restrictors may be incorporated into
faucets with resulting maximum flows
increasing roughly in proportion to water
pressure >;' » ' ^ " '' "--^ ' ",
Flow controllers are an alternative approach
incorporating pressure activated, variable size
orifices designed to provide a constant
maximum discharge, even with increasing ^
. pressure ', ' '
m Thermostatic mixing valves reduce faucet
flows by automatically mixing water to a'
desired temperature, thereby saving water
that would otherwise be wasted while the
user adjusts the independent hot and cold
controls to obtain a desirable temperature <.-
These valves are already being installed in a
large percentage of new construction..,", *s ,
Automatic shut-oil valves, available on - >'
some thermostatic mixing valves, help to >
prevent overuse and water loss Irom water i
left running accidently. >, '^^,)-,) ',, ^ . v ,s
Spray tap faucets, which cost only slightly "
more than conventional laucets. deliver ', -
1 water in a broad pattern ol droplets and are,
capable ol reducing the flow rate to 1 or 2 .,i
gpm. They are actually more efficient lor > ^v
washing and thus have a high potential lot v,
. public( acceptance.^
Aerators reduce* flow by Introducing bubbles
1 Into the water stream thereby reducing the
, degree ol splashing and creating the
"'appearance ol a greater flow than actually (
exists.' Water conserving aerators may reduce
flow rates to O75 gpm at supply pressures ."-
Horn 2O to 10Q psig (Milne, 1976>' (
72
-------
Shallower
vtrap
b) Water Saving lank Type (Shallow Trap).
While conventional tank toilets require 5 to 6 .
gallons per flush (with "quiet models" requiring as
much as 9 gallons per flush), shallow trap toilets
utilize only 3.5 gallons per flush. The shallow trap
toilet is a variation of the conventional floor
mounted close-coupled toilet Other than the
reduced size of its tank, it outwardly appears and
operates like other conventional water flushing
toilets (see Figure B-3> The water saving features
are achieved by modified design of the toilet
bowl Although the common siphon jet flushing
action is utilized (Milne 1976), the flushing rim and
priming jet have been designed to start the :
fiphonic action in a smaller diameter trapway s
with less water than conventional fixtures The
shallow trap means that less water is retained in
the bowl which in turn means there is less inertia
for the siphonic action to overcome (U.S. EPA.
198O> The result is that significantly less water and
a smaller tank can be used. The cost of a shallow
trap toilet is comparable to that of a conventional
tank model Although they had been slightly *
more expensive (up to S5) than conventional
models, the shallow trap model is now becoming
the norm and its cost is equal to or less than that
of conventional models in many areas. :-
c) British Style Dual Cycle. Dual cycle toilets
are designed with a dual flush mechanism which
allows less water to be used in flushing liquid
wastes (125 gallons/flush) than solid wastes (25
gallons/flush). The user, lor example, may pull the
handle up for flushing liquids and push down for
solids, or may simply hold the handle down for
the complete flush cycle needed for solids *
disposal Few dual cycle toilets are manufactured
in the United States, Moreover, the added rf" ""'
complexity in operation makes them somewhat
less socially acceptable (Metcall 8c Eddy, 1976). It
was concluded by Milne (1976) that the dual ,
cycle toilet must be regarded as highly,» ;
dependent on individual preferences and would
require an intensive public information ; * s,;
component Still a dual flush toilet is not costly
and could result in savings of one gallon or more
per flush (about 4 gpcd or 6 percent of present ,
indoor water use) over the savings achieved by
a shallow trap toilet In communities with limited
water supplies or severe quantitative restrictions
on wastewater disposal, dual cycle toilets could
be attractive.
'4t(X,". '
73
-------
{" "" d) Oil-Flush. A clear, odorless mineral oil Is ~
used lor waste transport in this comparatively '/V
expensive toilet system. Although clearly an ,V
effective water saving appliance (water use is -
zero), this system requires greater use of electricity
The approximate cost ol S2.5OO does not include
installation or the extra costs ol electricity. - .
chemicals and maintenance (Milne. 1976) , .
-, ' e) Composter This toUet system relies on
aerobic biological decomposition to eliminate
' organic wastes. A rich humus soil conditioner is *
the end product ol the organic matter
decomposition. No water is used, thus savings of
approximately 4O percent ol indoor water use
may be achieved Along with reducing waste-
water flows and producing a useful end product.
these systems may help improve groundwater
supplies. Operational problems may in some
cases be a limiting factor Despite the relatively
high cost (approximately $95O, not including
< installation), substantial savings could result if
installed as original equipment (Milne, 1976). -
1 0 Incinerator This is a sell contained toilet
system operated by electricity and gas, Burning /
1 eliminates all licruids and bacteria and reduces
' solids. Although possibly desirable where water
shortages exist or where central sewer systems
' are unavailable, the high capital and operating ,
costs and the need lor regular cleaning make
public acceptance quite limited (Milne, 1976).
g) Vacuum. Operation ol this type ol toilet
relies on vacuum action combined with a small
water flush. Since it requires only about 6 percent
of the water used by conventional toilets.
substantial savings in indoor water use would
result The cost of these systems varies, depending
upon such factors as the total number ol homes.
housing density, and type ol soil This system is
not appropriate lor installation in a single housing
unit Instead, it is efficient when installed in com
munity sized developments and in commercial or
institutional settings. Agaia although this system
uses less water, it requires greater consumption,of
energy (Milne, 1976). M,- / , < VM >> ^ > t <
r It is Important to note that some of the more
exotic systems (freezing, composting, incineration1
units) are often not recognized by codes due to
their recent development and to uncertainties on1
potential health hazards. Use of these systems is
usually reserved lor remote locations where ,.' 4
water supplies are severely limited or sewers are
not available and septic tank soil absorption', -
systems are not functional (Milne, 1976> '-V '^ , iu
','4) Home Appliances. Dishwasners and ' "
washing machines are the two major water using
, home appliances. Both appliances also'; * \[ -'
significantly ailed home energy consumption'
'' * due to the" amount of hot water they require",
t^' a) Qothes Washers. Conventional full size'
washing machines use between 4O to 55 gallons '
for a full wash load Most manufacturers now;
provide models that are designed with water;
and energy saving in' mind In addition to r> f
improved consideration ol water use with full
loads and complete cycles, many models now -
allow the user to make load size, cycle, and r^'
water temperature adjustments which can result'
in substantial savings. "Suds saver" models are
also available; they utilize a separate holding
sink to store and then recycle wash water lor'
' subsequent loads. Consumer Reports 0978)
provides a recent review ol washing machine
models including water and energy efficiency
1 > b) Dishwashers. These appliances use 12 to
18 gallons per full cycle Many models feature
cycle adjustments controls which can reduce
. wafer use to as low as 7 gallons per cycle by
eliminating a wash/rinse cycle from the full . -
cycle Many new appliances are now labeled
according to the amounts of water and energy
they require in operatioa;^ *?!>''
homes or in the distribution system servicing a
number of homes. The pressure in a distribution -
zone often must be maintained at a higher level
than is necessary for residences - usually to,* ,
insure adequate supplies for fire fighting Pressures
around 4O psig are sufficient for residences,,while,
business or downtown regions may require < ,. -
pressures of 6O-75 psig O^air and Geyer. 1965). For
new single-family residences, it will generally be
practical to install a pressure reducing valve
(such as that shown in Figure B-4) in home
service lines to reduce pressure to 4O pstg. ^ K
wherever it exceeds 6O psig For businesses and
high rise living complexes, higher pressures may
be required and the practicality of installing a
pressure reducer would have to be decided on a
case-by case basis. Pressure reducers may cost'
from $3O to $5O. but when installed as part ol'J 'v
, new buildings, the labor cost tor installation ',;'
should be Insignificant' /r^,^,"^ ?^ 'T ^
Homes being fitted with1 water scrvinVtixtures
and appliances would not experience as great a
decrease in water use from Installation of a
pressure reducer as would a home without water
saving features. For example, a reduction in line
. pressure from 6O to 4O psig would reduce the
, maximum flow rate of a low flow shower head ,
on the average from 29 gpm to only 2.4 gpm, .
while the reduction with a conventional shower
head may be several gpm. (Double counting is
discussed more tuUy.in Appendix C.) Estimated
74
-------
Figur* B-4 Typical Prastura Reducing Voir*
savings from pressure reducers must be based on
both the amount of pressure reduction
accomplished and the types of water using
fixtures in the buildings.
b Installation of Flow Control and Water
Saving Devices in Existing Residences and
Businesses (i.e, Retrofitting).
Until recently, say 1975, most water using
fixtures were designed with little attention placed
on efficient water and energy use This fact is
dramatized by Figure B-l which illustrates the
difference between old, "conventional" shower
heads and new, low flow shower heads. Now,
even though awareness of water efficiency has
increased manufacturers and builders are still in
transition toward products that are more water
and energy efficient Thus, essentially all buildings
constructed before 1975 and most built prior to
198O have fixtures and appliances which utilize
relatively large amounts of water. However,
many of these fixtures can be easily retrofit with
water saving devices which are relatively
Inexpensive, maintain the quality of service, and
result in significant water and energy savings
and wastewater flow reduction
Motivated by limited water supplies, drought
energy shortages, and the increasing cost oi var-
ious community services, many governmental
units have begun to spotlight the potential sav-
ingi Horn rtlrolltttng and lomt havt conducttd
major retrofit campaigns. Several diilerent
approaches are available includlngi >
« Public information on potential benefits - but
reliance on property owners to purchase and
install appropriate retrofit devices.
Free inspection and retrofit installation at the
request of the property owner.
Public information and free distribution ol
devices at a central location where property
owners can obtain them.
Mass distribution of retrofit kits by hanging
them on door knobs with suitable
accompanying installation instructions and a
public information campaign.
« Mass mailing of devices with instructions and
a simultaneous public information campaign.
House-to-house visitation and free installation
of the retrofit devices (at the initiative of a
government agency or utility, but with the
property owner's permission).
The last two approaches - mass mailing and
house to-house free installation - are really the
only approaches that have achieved consistently
positive results in terms of significant percentages
ol implementation
Three examples of large, successful retrofit
programs are the following!
California Department of Water Resources.
During the 1976-1977 drought DWR 0978)
conducted "A Pilot Water Conservation Pro-
gram" in which it experimented with various
retrofit program approaches. Based on that
experience. DWR is continuing its retrofit
efforts with mass mailings of kits to residents in
selected county/municipal areas. This pro-
gram is funded by several million dollars of
special state appropriations.
One of the six areas comprising DWR's
1976-1977 pilot study was the primarily residen-
tial community of Oak Park, a relatively new
development of approximately 75O single
family houses. The Oak Park retrofit program
consisted of free, door to-door installation of
free toilet dams and shower head flow
restrictors. By June 1977,88.6 percent of the
total community had been retrofitted A
survey conducted nearly two years later
(April 1979) revealed that 59 percent of the
total residences in the community had toilet
retrofits in place and 56.8 percent had shower
retrofits in place. Dry weather wastewater
Hows are reported to have decreased by 25
percent (California DWR September 1979).
DWR's recent efforts have involved mailing
retrofit kiti to 16 million households in May
1980, the program's tiitcUvtntsi wai
determined tor the community oi Santa
-------
California DWR Plastic How Restrictors
External now
Controller
U.S. Department of Energy
Flow Restrictor
Figure B-S. Typical Shower Retreat Devices
Barbara It was found that 37 percent ol the
total population had Installed the toilet bags
and 17 percent had installed the shower
inserts (Heath, September 198O).
Washington Suburban Sanitary
Commission. Over the past 1O years the
WSSC has conducted an intensive conserva-
tion campaign to alleviate water supply
shortages and avoid major capital
expenditures. Among the major components
ol the campaign were the bottle kit and
shower device distribution programs. In 1973.
over 3OO.OOO kits containing three plastic
bottles (for use in toilet tanks), dye pills for
toilet leak detection and an instruction
booklet were distributed including door-to-
door distribution to nearly all ol the 2OO.OOO
single-family homes in WSSC's service area In
a follow-up survey, 93 percent ol the
respondents Indicated that they had used
one or more ol the bottles In their toilet tanks.
Another program was Initiated in 1974
Involving the free distribution of shower flow
control devices to those WSCC customers who
requested them. Between 75.OOO to 1OO.OOO
WSSC customers were estimated to have
received the shower devices. Thirty-six per-
cent of those responding to a follow-up
survey Indicated they had received tho
devices, and 41 percent ol these (i.e, 15 per-
cent of the respondents) indicated that the
device was installed. The large yearly
fluctuations In water use as well as the imple-
mentation of other conservation measures
makes it dillicult to assess the effectiveness ol
the device distribution programs in reducing
water use. However, a comparison ol water
use between 1968 and 1975 among those
water users surveyed indicated an overall
water use reduction ol 1O percent (Sharpe
and Fletcher. 1977).
U.S. Department of Energy. The DOE
conducted a massive "Low Cost/No Cost"
energy conservation campaign In New
England during the Fall ol 1979, Their mass
mailing campaign ot a booklet with energy
saving tips featured "hot water" energy con-
servation as a "new thrust" lor the energy
saving message. In order to give this thrust
added emphasis and to provide added
motivation to homeowners, they Included a
flow restricting shower insert A follow-up
evaluation ot the campaign (US. DOE 198O)
has shown homeowner response to be very
favorable with over 29 percent ol the
households sampled reporting they had
-------
Installed the shower inserts.
In summary, retrofitting is extremely attractive
in terms of potential water and energy savings
and cost-effectiveness. Retrofit materials can be
obtained inexpensively either by individual
properly owners or in the form of retrofit kits
assembled and distributed by public agencies.
Several approaches are available for distribution
of retrofit materials - mass mailing is one
straightforward and effective technique. The
major hurdle is achieving a high percentage
installation rate. The significant choice in
designing a retrofit campaign is (1) relying on
property owners to install the devices (2O to 3O
percent installation) or (2) organizing free
Installation utilizing trained personnel (8O to 9O
percent installation). In either case a carefully
designed public information program is crucial
this topic will be treated extensively in Part IV of
this flow reduction series which is to be published
as a separate volume.
The following subsections locus on the nature
and effectiveness of available retrofit devices
which could be used in a retrofit program.
1) Shower Retrofits. A variety of devices lor
retrofitting showers exists as is illustrated by Figure
B-5. They can result in major reductions from the
typical 5 to 6 gpm flows.
Plastic flow restrictors or orifice inserts reduce
maximum flow rates to 2.5 to 4.5 gpm. depending
upon the particular device and line pressure.
Figure B-6 shows the range of effectiveness lor
restrictors tested by California DWR (1976).
Installation involves placing the device in the
water line before the shower head and is usually
easy to accomplish.
Sometimes diiierent device designs are
required depending on whether a ball and
swivel shower arm is present. California DWR has
addressed this problem by distributing two
diflerent restrictors (Figure B-5). one lor ball and
swivel pipes and one lor threaded pipes Such
devices can be purchased lor less than one
dollar/ (or bulk purchases in mass distribution pro*
grams the price may be less than ten cents each
(California DWR 1978>
Pressure compensating external flow
controllers (Figure B-5) deliver How at a constant
rate regardless of line pressure (Figure B-6) and
can be chosen to provide any ol several desired
maximum flows. The available range ot flow
rates is 1 to 45 gpm. These devices are more
expensive (two to eight dollars) than the plastic
restrictors. They are screwed Into the lead-In pipe
ahead ol the shower head and are generally
Incompatible with a ball and swivel type ol
shower arm.
Source: California DWR. 1978. Bulletin 191. Appendix G.
Typical
internal
restrtctor
Typical
external
controller
Range ol results lor shower retrofit devices
20 40 60 80
Water Pressure (pslg)
Figure B-6. Shows: Retrofit Devices Comparison To
ConTtntlonal Shower Head*
Due to their low capital cost (S4-S2O). new
low flow shower heads, which were discussed
previously under new const ructioa can also be
considered lor retrolit. Low flow shower heads
may provide a more acceptable shower than
oritice inserts or flow controllers, especially 11 the
existing "conventional" shower head needs a
high flow rate to provide a dispersed spray.
2) Faucet Retrofits. Devices lor reducing
faucet flow are ol two main types, designed lor
in-line placement or attachment at the laucet
outlet ;p.,> Y._
In-line devices are placed ahead of the
faucet to reduce the opening through which the
water passes. Usually these are restrictors or flow
controllers such as those used for showers (Figure
B-5). The inserts can be purchased for approx-
imately Sl.oo each and otten are distributed Iree
in retrolit campaigns. The flow controllers are
usually more expensive ($2 to $8) but are usually
designed to compensate lor pressure variations.
In-line devices can reduce laucet flows from the
normal flow average ol 5 apm to O.5 to 4 gpm,
averaging about 2 gpm.
Aerators and spray taps used In retrofitting
77
-------
Plastic Bottles
Plastic BOB
Dual Cycle Retrofit
Pull up lor full flush.
Push down lor short flush
;.-..-to;.'!.-' "
figure »-7, Tbilet Itfaoflrttaa lechnlquti
78
-------
operate in the manner discussed previously They
are attached to the laucet outlet (in compatible
situations) and can reduce flow rates to between
O75 and 3 gprrx averaging 15 to 2 gpm They are
inexpensive retrofit devices and. as in new con-
structioa can provide faster washing and rinsing
thereby contributing additional water savings,
3) Tbilet Retrofits, Toilet retrotit devices are
specifically designed to reduce the volume o!
water used for flushing in existing conventional
tank type toilets. They can be any ot several
types, as indicated by Figure B-7 Plastic bottles
containing a weight and O5 to 1 gallon ot water
can be placed into the tank, thereby displacing
an equal volume ol water trom the active flush
mode Plastic bags, which hang inside the toilet
tank and Junction in the same manner are also
widely utilized, especially in mass mailings. They
save about one hall gallon per flush. Tank dams
(usually installed in pairs, as shown in Figure B-7)
are pieces ol plastic or rubber-coated metal
which can be shaped into an arch and inserted
vertica^y between the tank walls and abutting
the tank base This creates a pocket ol water
which is precluded from draining into the bowl
saving approximately 15 gallons per flush
Installation is not difficult and the dams can
easily be adjusted to satisfy the householder
Ol course water can also be displaced with
bricks and other objects. Savings Irom these retro-
lit etlorts are variable depending on the specilic
technique used and adjustments needed to
maintain salislactory Hushing Savings are usually
between O.5 and 15 gallons per flush Use ol
bricks is Irequently not recommended because ol
their tendency to disintegrate in the toilet tank
Dual cycle tank inserts can also be used to
retrolit conventional toilets. They operate similarly
to the dual cycle toilets lor new construction
discussed in the previous section This retrolit
device can generally alter a toilet so that 2
gallons will be used lor flushing liquids and 3
gallons lor flushing solids, a savings ol at least 3
and 2 gallons per flush, respectively (Metcall 8c
Eddy, 1976)
Comparisons ol available toilet retrolit
devices show costs to vary Irom less than $1 up to
$1O, with most not exceeding $5. Ol course home
Improvised devices are generally Iree Given
their Jow cost and relatively long expected We,
toilet retrofits are attractive water conserving
devices.
4) Other Retrofitting. Additional physical
devices to lessen wastewater flows Irom existing
buildings tend to be more cosily undertakings.
The lour major Hems which could be considered
ore water meters, pressure reducers, and water
efficient clothes washers and dishwashers. Ol
these the pressure reducer is the next most
practical item provided the building's main sup-
ply line is readily accessible such as in a '
basement These devices cost $3O to $5O and
generally should be installed by trained
professionals, thus their cost-effectiveness may be
marginal depending on the labor cost involved
Nonetheless, in situations with high pressures in
the water main they can result in significant cost
effective saving (See the discussion in the section
on new construction lor further details on
performance) Where pressure reducers are
installed in existing buildings care must be taken
to avoid interference with lawn sprinkling
systems or other water using features designed to
utilize the existing high pressures.
Installation ol water meters in existing
buildings is dependent on a number of
considerations which go beyond reductions of
indoor water use and the resultant wastewater
flows. They are discussed in more detail in the lol
lowing section on water pricing and rate
structures.
Retrofitting with water and energy efficient
clothes washers and dishwashers in existing
buildings is generally cost-effective when
purchasing new or replacement models lor other
reasons. It may be a relevant consideration in
deciding whether to replace a machine or
undertake a major repair effort
2 Types ol Water Pricing Structures
Water pricing is the primary economic
method ol achieving water conservation and
thereby flow reduction For pricing to be an effec-
tive conservation incentive, however, meters must
be installed to establish the essential link
between the price users pay lor water and the
quantity ol water they use Thus cost-eflectiveness
may not be the only relevant criterion in
deciding whether to install meters in presently
unmetered areas. Equity considerations may lead
to meter installation despite Its relatively high
cost
Residential water prices are usually
established so that the revenues obtained cover
the cost ol supplying water to customers. This can
be accomplished using a variety ol rate
structures, although these structures differ greatly
In the degree to which they provide an Incentive
to reduce water use. Essentially threo elements
must be present lor even a conservation-oriented
rate structure to be cm effective conservation
measure, utility knowledge ol customer water use.
-------
'
Flat Fee
Quantity
Uniform Commodity Pricing
4 ' * ^ ,.
Quantity
c.
"c.
I
S
I
I
Quantity
Quantity
Decreasing Block
Quantity
Increasing Block
Quantity
Quantity
Quantity
n0ur«B4 Foui Waltt Prtclng Stiucturti
eo
-------
customer knowledge and understanding of the
rate structure, and customer ability to assess the
economic impact that this rate structure will have
on an individual residence (Rice and Shaw, 1778>
Therefore, an effort to motivate water conserve
tlon through a rate structure must be carefully
planned. Specifically , ;
There must be metering
Meter reading must be reflected on the bill
and usage must be compared to some norm.
A new rate structure must be accompanied
by an intensive public information campaign
to draw awareness to the water usage/cost
relatioacnip
Care must be taken that the new rate
structure produces enough revenue, even
when people respond by conserving, so that
rate increases do not become necessary so
soon that they disrupt the water users'
enthusiasm for conservatioa
Several types of water pricing/rate structures
which are now utilized are described below and
some are illustrated in Figure B-8. They obviously
provide differing incentives for and against wise
water use
Flat lee pricing involves charging customers
a set fee per unit of time (e g, monthly,
quarterly) regardless of how much water is
used. This constant charge may be varied
according to the class of use or size of the
service line (Nelsoa 1977). It is usually used
where meters are not installed thus neither
the utility nor the water user knows how
much waste occurs. Flat lee pricing provides
no conservation incentive and actually
encourages water wastage since the cost is
not aUected by the quantity used
Decreasing block rate, the traditional form of
water pricing, consists of a series of prices per
unit volume for blocks of water used The
applicable price decreases as the quantity of
water used increases. This price structure
favors large water users such as water
intensive industries since they will pay
substantially less per unit than do smaller
users. The incentive to conserve diminishes as
water use increases since total water cost is
increasing at a decreasing rate.
Uniform commodity pricing involves
charging the same price per gallon
regardless of the quantity of water used or the
size ol meter service, Since the total cost of
water used Incrjvtses at a constant rate, this
pricing scheme ocx?* provide a significant
Incentive to convtrvo it '^e customer uses
.inly half as much vcrtui cs another, the
b"J i'^Aly haw at rvuch as well. v
Peak demand pricing, commonly
implemented as summer surcharges for water
use exceeding some baseline amount Is
designed to promote conservation during
those periods when the utility experiences the
greatest demand or its most limited supply.
This pricing scheme usually focuses on
reducing outside water use lor landscape
irrigation - the category of use thought to be
most sensitive to price It should be pointed
out that this pricing scheme will have little
effect on wastewater flows if reductions occur
mostly in outdoor water use
Increasing block rate is the most conserve *
tion oriented rate structure currently in
practice Increasing numbers of utilities are
adopting this form of pricing schedule as an
effective means ol reducing water use In
contrast to the decreasing block rate structure.
the unit price of water increases in a step-like
fashion as the quantity of water used
increases. Many communities have achieved
substantial reductions in water use by
instituting increasing block pricing Evidence
of the effect of instituting this pricing structure
in the Washington Suburban Sanitary
Commission service area indicates that
significant reductions are occurring in resi
dential use (McGarry. 1976>
Wastewater service pricing in some areas
underscores the link between water use and
wastewater flow and provides additional
incentive for water use reductioa One
approach is to make wastewater charges
dependent on the metered level of total
water use For an Increasing block rate, this
would mean wastewater rates as well as
water rates would increase with Increased
water use. thereby increasing the overall
incentive to conserve (Citizens Advisory
Committee. WSSC. 1977> However, in areas
which use large amounts ol water for lawn
sprinkling, this pricing approach would be
regarded as unfair by many people They
would be paying large unit prices for waste-
water service when that water was not
contributing to wastewater (lows to the treat*
ment plant.
3. Building and Plumbing Code
Changes
Legally mandating the Installation ot water
saving devices by making appropriate changes
in building or plumbing codes is an effective way
of reducing water use and wastowater flows.
Water saving toilets are now required by local
plumbing codes In several areas and by several
-------
stales. For example, the California legislature
enacted a bill In 1976 which provides for the use
ol water saving toilets in all new buildings
(Nelsoa 1977> Regulations can also be set
requiring the installation ol devices such as low
flow shower heads, faucet aerators and pressure
reducers in new construction, and such rules
have been adopted to varying extents in several
stales. Unlike some ol the other flow reduction
measures, the eHectiveness of code changes is
not strictly dependent upon consumer response
Once water saving devices are installed in new
constructioa conservation and How reduction are
automatic This contrasts with other programs
where retrofit devices may be distributed but not
installed, or consumers may respond little to a
change in price
Changes in building and plumbing codes
will produce results more significant over the long
term than short term. Benefits from implementing
these legal measures will usually be greatest in
areas experiencing growth. Due to sociopolitical
acceptability, costs, and enforcement problems.
the use of code modifications to require
retrofitting of existing residential units is likely to
be impractical (Flack, et al, 1977).
Any code changes to encourage water sav-
ings should be accompanied by an effort to
obtain the support ol professional plumbers and
building Inspectors who will be close to, and
Impacted by. these changes. This is just one
aspect which can be covered in a public inlor
motion program. One survey ol professional
plumbers on the rolls of the Washington Suburban
Master Plumbers Associatioa Inc indicated
substantial plumber knowledge ol and support
lor code changes requiring installation ol water
saving devices (Sharpe and Fletcher, 1977> Two
examples ol code changes which have been
implemented are provided in the next two
subsections. Subsection c presents the standards
advocated by the Plumbing Manufacturers
Institute as suitable (or nationwide applicatioa
a Excerpt From the Fairfax County
(Virginia) Plumbing Cod*.
As quoted in McGhee et al 097$). the following is
an excerpt from the above referenced coda
Water Conservation
In all new construction and in all repair and/or
replacement ol fixtures or trim, only fixtures and
trim not exceeding the following (low rates
and/or water usage shall be installed These rates
are based on a pressure at the fixture ol 4O to 6O
psi.
Water closets. '
flushometer type.
Urinals, tank ,
type,
Urinals.
flushometer typei
Shower heads
Lavatory, sink
laucets
Lavatories lor
public use,
Water closets,
tank type.
3 5 gal. per flush
3O gal per flush
. ' i
*
3O gal per flush f
3 O gal per flush
3Ogpm
4Ogpm
Faucets ol lavatories
located in rest rooms
intended lor public use
shall be ol the metering, or
sell closing type.
b. Authorization and Connection
Requirements Issued by the Washington
Suburban Sanitary Commission
As quoted in Metcalf and Eddy (1976), the follow
ing is an excerpt from the above-referenced
requirements.
1) Tank type toilets for new single family homes.
apartments, rental townhouses. motels, hotels
and commercial buildings will be required to
be of a design that provides a maximum
flush not to exceed three and a hall gallons.
or. If a conventional toilet is used, must be
equipped with an available water closet
reservoir device designed to reduce the flush
to three and a half gallons or less. After July I
1973. the toilet designed lor the maximum
three and a hall gallon flush will be required
in the installation ol all tank type toilets
2) Water saving shower heads to limit flow to a
maximum ol three and a hall gallons a
minute will be required in all units.
3) Aerators, which result in a flow reduction to
approximately lour gallons a minute, will be
required on all kitchen sinks and lavatories.
4) Installation ol a pressure reducing valve on
the incoming service to the structure will be
required (or all properties where the
Incoming water pressure is expected to
exceed 6O pounds per square Inch. The
Pressure Reducing Valve must provide
adjustment oi the pressure (or the household
service to within the range ol 5O to 6O psl
5) Cellar floor drains may not be connected to
the sanitary sewerage system. When floor
drains are installed, they must discharge to
an approved storm drain. Discharge to the
surface ol a lot would be permitted only
when a storm drain Is not available to
receive drainage. All buildings erected with
cellars or basements In areas known lo have
-------
a water table above the basement floor will
be required to have foundation drains
around the outside ot the building with a
satisfactory point of discharge This require-
ment is included as a recent revision in the
WSSC Plumbing Code and is mandatory for
all new structures.
c. Water Conservation Plumbing Code
Recommendations of the Plumbing
Manufacturers Institute (Church. 198O>
Water closet - tank type Tank type water
closets shall flush with an average of 35
gallons and a maximum of 4 gallons,
Water closet - flushometer type. Water
closets flushed with a flushometer valve shall
flush with an average of 3O gallons and a
maximum ot 3 5 gallons.
Shower heads. Maximum flow from shower
heads shall not exceed 275 gpm (+25 gpm)
at pressure ranges from 2O to 8O psig Water
supply will be provided at temperatures not
to exceed 12O8 F at the showerhead in public
use installations.
Lavatory and kitchen faucets. Faucets will
not exceed a flow rate of 2.75 gpm (+25 gal)
at pressure ranges from 2O to 8O psig where
hot and cold water supply are in the lull
open position.
Pressure regulating valves. Where the
service water pressure to a building is in
excess of 6O psig. an approved water
pressure regulator with strainer shall be
installed to reduce the pressure in the
building water distribution piping to 6O psig
or less. Exceptions to this requirement are
service lines to sill cocks and outside
hydrants, and main supply risers in tall
buildings where pressure from the mains is
reduced to 6O psig or less at the fixture
branches or at individual fixtures. (This
language Is edited from the Standard
Plumbing Code)
Other. It is suggested that all other water
using fixtures or devices be evaluated for
water usage on the basis of the actual
requirements of the installatioa with the
subsequent setting of maximum usage limits
by the local jurisdictions and engineering
practices. (Water softeners, wash sinks, special
fixtures, etc)
Note that the references for this appendix are
Included in the list of References, beginning on
page 65
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Appendix C
Relative Economic Benefits of Selected Water Saving
and Flow Control Devices
This appendix provides additional informa
lion for the flow reduction analyst/planner to use
In developing and evaluating a first cut program
and becoming sensitive to potential modifications
or alternatives to the program Information herein
supplements Step C and Step D in Part II and
Appendix B by providing the following informa
tiorii
A measure of the relative monetary benefits
of various water saving and flow control
devices (see below).
Examples of methods lor calculating annual
water savings, annual energy savings and
the annual net monetary benefits associated
with various water saving devices (page 87).
The effect of combining various flow reduc
lion measures and how to deal with double
counting In calculating water and energy
savings and their associated monetary bene
fits (page 87>
L Relative Monetary Benefits Of Flow
Control Devices
This section provides information on a group
of water saving and flow control devices that
generally provide monetary benefits justifying
their cost The primary intention is to indicate a
way that their relative cost effectiveness can be
evaluated The annual net monetary benefits
(annual monetary benefits minus annual
equivalent monetary costs) are calculated for
each device, wherei
Monetary benefits are the savings in water
supply, waslewater and energy (to heat
water) costs associated with the reduction in
water use and wastewater flow brought
about by the device.
Monetary costs are the additional costs, over
the costs ol the conventional fixture or
appliance, ol purchasing, Installing and
maintaining the water conserving device.
In calculating the net monetary benefits, costs
are expressed in terms ol the annual equivalent
cost over the service life of the device, and
subtracted from the annual savings in water sup-
ply, wastewater and energy costs. Thus, any
device lor which the net monetary benefits are
positive produces dollar savings which
economically justify the additional investment
costs.
This analysis emphasizes the relative eco-
nomic benefits of various devices. The
assumptions made here may not be appropriate
lor determining the cost effectiveness of devices
within the context of a particular community
These assumptions should be carefully examined
and altered where necessary to reflect the
situation in a given community
a Major Assumptions
The net monetary benefits of each water sav-
ing device or appliance are determined within
the setting of a lour member household. Note that
the net benefits do not represent net monetary
savings to the household unless the community is
able to achieve 1OO percent implementation
Interest here is in maintaining a community
viewpoint Therefore the water supply, waste
water and energy costs used in the analysis are
representative of the utilities' (and thus the com
munity's) marginal costs of providing these
services The intention is to provide a measure of
the relative cost effectiveness of the devices
within a community flow reduction program. It is
emphasized that these numbers are appropriate
only for an approximate comparison of devices.
A full cost effectivenesss calculation would
require figures which are much more precise
Assumptions generally applicable to the
analysis include,
A combined marginal cost of water supply
and wastewater treatment equal to
SO3O/1OOO gallons. This figure is only a
rough estimate of the marginal cost of
providing these services and is sufficient for
the comparative purpose of this analysis. It is
based on a typical average cost ol
SO6O/1OOO gallons lor water supply and a
typical average cost ol SO9O/1COO gallons
lor collecting, treating and disposing ol waste-
water (US EPA. 1979). Marginal cost is assumed
equal to 2O percent ol average cost to reflect
the large proportion ol capital costs involved
Ol course, lor the marginal costs to be even
this substantial Implementation and effects
must be community wide and long term.
A marginal cost ol supplying energy to water
users equal to $O45/therm This is the
approximate amount that Pacific Gas and
Electric, a northern California utility, now pays
at the margin lor Canadian gas. Note that '
inflation ol natural gas prices over and
above inflation ol other prices is not taken -
into account in this analysis, Thus, the mone*
tary benefits indicated lor those devices <> >'
Inducing signilicant energy (Irom hot water)
savings are conservative.
Preceding page blank
85
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Fixture
Toilet
Shower head
Faucets
Pressure
Reducing Valve
Washing
Machine
Dishwasher
Approximate Annual Household Annual Household
Cost over Water Savings Energy Savings
Conventional over Conventional over Conventional
Type/Device" (S s per device) (gallons) (BTUs) ,
Water saving
tank type (NC)a
i
Dams In
calculating annual equivalent cost and payback period
11000
11000
5500
14600
5800
7300
5800
5800
2900
2900
2900
9500
9500
4400
1500
-
2680000
3350000
2680000
2680000
804000
804000
804000
2610000
2610000
1510000
1 100000
Annual
Net Monetary
BeneWs
(Ss)be<1
j
330
230
160
340
1380
1668
1360
1290
300
420
390
1200
880
570
490
Payback
Period
(years)
00
36
00
26
00
04
02
08
40
07
15
23
51
36
10
c Assumes 2 toilets. 2 showers and 3 laucets per 4 member
residence
d Does not make allowances (or future Increases In energy
prices over and above inflation In other prices.
table C 1. T>M Relative Economic Benefits From A Community Viewpoint Ol Common Water Soring Device* And Appliances
An Interest rate ol 7.375 percent the WRC rate
which the EPA has stipulated lor use in its
Cost Effectiveness Guidelines.
b. Results of th« Analysis
Table C-l shows the results of the analysis for
common waler saving fixtures and devices, In
addition to the annual net monetary benefits, the
table shows the payback period associated with
each device. As used here, the payback period is
the time in years required to recover the cost of
the device from the savings in waler, wastewater
and energy costs brought about by the device,
using an interest rate ol 7.375 percent. (Note that
this differs Irom another interpretation of paybacl
period which does not take into account the tim<
value ol money).
The following section sets lorth the
assumptions made lor each device in Table C-l
and provides examples ol calculation methods
used. As additional and improved data
regarding the effectiveness ol certain devices
and their water and energy saving conse-
quences become available, the assumptions an
results expressed here should be updated
accordingly.
-------
2, Examples Of Calculation Methods
Used
This section provides a series of tables
Indicating the assumptions used for each generic
type of device listed in Table C-l These
assumptions are in addition to major assumptions
lor the overall analysis provided in Section la
above Tables C-2 through C-7 also provide
examples of calculation methods used for specific
devices within each generic type These sample
calculation methods for water and energy sav
ings and the annual net monetary benefits can
be applied using any appropriate set of
assumptions
3. Consideration Of Double Counting
Table C-l presents the estimated savings in
water, energy and costs lor particular devices
and appliances considered individually Because
some of the devices reduce water use in the
same manner, the savings that should be expect
ed from combinations of two or more of these
devices does not necessarily equal the sum of the
estimated individual savings. Failure to take these
duplicative functions into account will result in
double counting and therefore an exaggerated
estimate of the potential savings from this
combination of measures.
Double counting will be most significant
when considering installation of a pressure
reducing valve in combination with a faucet flow
control device or a shower flow control device.
Both the pressure reducer and the faucet or
shower device save water by reducing the flow
rate/ thus the savings they produce In
combination Is somewhat less than the sum of " ',
their individual savings. Precise measurements of
the combined effect of these devices do not exist
In a generally applicable form. At best only a
rough and very simple method of dealing with -
double counting can be described Assume, for
example, that the following three devices are to
be installed.
A plastic shower head Insert Individually sav
ing 4 gpcd
A laucet aerator Individually saving 2 gpcd
A pressure reducing valve individually sav
Ing 65 gpcd
Since the shower and laucet devices produce
water savings which are fully additive, they may
be considered as a single measure, producing
savings of 6 gpcd. If the pressure reducing valve
were the only device Installed it could be expect-
ed to save 65 gpcd The water savings expected
from the combination of the three devices must
be greater than 65 gpcd (the savings expected
from Installing the device which produces the
maximum savings when installed alone) and less
than 125 gpcd (the sum of the savings from all
three devices) A rough estimate of the combined
savings can be made by taking half of the
difference between these values and adding it to
the minimum value In this example. 3 gpcd
(which is hall of (125 minus 65)) would be added
to 65 gpcd the minimum value, producing an
estimated combined savings of 95 gpcd
For alternative estimates of water saving
effects of combinations of measures, see Flack et
ai, 1977 References for this Appendix are
included In the list beginning on page 65
\
a?
-------
Assumptions »
Each house has 2 showers,
50% ol bathing Is showers
Water used lor all bathing Is 20 gpcd therefore water used (or showers is 10 gpcd
Low How shower head without cutoll saves 40% ol water used In showers or 4 gpcd
Low How shower head with cutoll saves 60% ol water used in showers or 5 gpcd
Plastic insert How varies with pressure saves 40% ol water used in showers or 4 gpcd
Pipe lilting controller with constant How rate saves 40% of water used In showers or 4 gpcd
Water is heated Irom SOT to 105T
') Note that these are very conservative assumptions
Sample Calculation
persons days gallons *
Annual water savings - 4 gpcd X 4 nouse X 365 ^p = 5 840 year
Annual energy savings - 5 840 gye'°"S X 8 34 x 55 de9rees " 2 678 808
Annucl monetary benefits - (5 840 22 X iooo^||ons)+ (2678 808 ySx lOOOQO BTUs/lherm)"31 ?6 + $1206 - S1382
Annual equivalent cost (for 2 Inserts) - S 19
Annual net monetary benefits -S1382- 19-S1363
Payback period (assuming 7H% Interest) » 15 years
Table C 2Example Calculation For Shower Head With Plastic Insert and Flow Varying With Pressure
i
Assumptions
Each house has 3 sinks
With conventional fixture water used lor cooking drinking and lavatory use Is 7 gpcd
Each faucet water saving device reduces conventional use by 2 gpcd
Cold water lemperature Is 50 F 60% ol use Is warm water at 105°F
Sample Calculation
. Annual water savings - 2 gpcd X 4 Vggg X 365 ^ - 2 920 2^
Annual energy savings - 2 920 year X 60 warm water X 8 34 degree x ^ degrees ~ 803 642 -,
. Annual monetary benefits - (2 920 S2J2Q* x ^^2^) + (e03 642 SxToTjWWs7Ir^)-S88 + S362-S450
Annual equivalent cost (lor 3 aerators) - S 58
Annual net monetary benellls - S4 50 - 58 - S3 92
Payback period (assuming 7tt% Interest) - 1 5 years
Table C 3 Example Calculation For Faucet Aerator
Assumptions
Each house hai 2 lolled
Each member ol household Hushes toilet 5 times per day
Sample Calculation
, .gallons saved . flushes days persons ,, gallons saved
Annual water lavlngi- 15* j-jjy; - X5 -359- * 365 year X 4 house ""^SO* year -
Annual monetary benoflli - 10,950 ?year X IOQQ qallon» " S3 29
Annual equivalent cost (lor 2 pair at S5 00 per pair) - S 97
Annual not monetary benefits - S3 29 - 97 - S2 32
Payback period (assuming 7Vi% Interest) -36 years
Table C-4 Example Calculation For Toilet Dam
-------
Assumptions.
Saves 10% ol In house water use or 6 5 gpcd
60% ol water saved Is warm raised to 105°F Irom COT
Sample Calculation
oersons days aallons
Annual water savings - 6 5 gpcd X 4 ^-55- X 365 y^ - 9 490 Myeqr
aallons BTU s/gallon BTU s
Annual energy savings - 9 490 =r^jr- X 60 warm water X 8 34 de^ree X 55 degrees -2 611 838 -
Annual monetary benems-(949QgX i^llpj+ (2611 838X 1M^|ffe,heTO)-S2 85 + 311 75-S1460
Annual ecjutvalent cost - S2 90
Annual net monetary benefits - S 1 4 60 - 2 90 - S 1 1 70
Payback period (assuming 7%% Interest) - 2 3 years
Table C 5 Example Calculation Foi Installing Pressure Reducing Valve in New Construction.
Assumpaons
Water use with conventional type Is 9 gpcd
Water saving type saves 33% ol water use or 3 gpcd
75% ol laundry washing uses warm water heated Irom 50°F to 105°F
Sample Calculation
persons days gallons
Annual water savings - 3 gpcd X 4 house X 365 ^p - 4 380 year
gallons BTU s/gallon BTU s
Annual energy savings - 4 380 'year X 75 warm water X 8 34 a^f^ x 55 degrees - 1 506 830
Annual monetary ber»Mi -(« MO ^j^ X |flM gallon,) +C 506 830^X1MoM |ff s/,herm)-Sl 31 +S678-S809
Annual equivalent cost - 52 43
Annual net monetary benefits - S8 09 - 2 43 - 55 66
Payback period (assuming 7H% Interest) - 3 6 years
Table C 6 Example Calculation For Clothes Watbei
Assumptions.
Water use with conventional type Is 4 gpcd
Water saving type saves 25% ol water use or 1 gpcd
Water Is healed from 508F to 140°F
Sample Calculation.
persons days gallons
Annual water savings - 1 gpcd X 4 rnou,e X 365 y^f '-460 yeaT"
. . .gallons , BTU s/gallon ^ . . ~,« ... BTlTs
Annual energy savings - 1460 vyeqr x 8 34 degree 'x w deare«* " 1095,876^r
Annual monetary benefits - (l,460 ?ye'q"' X iflflO gallons) + 0 O95-876 yiaT x lOOOOOBTU's/therm)" S 44 + S4 93 - SS 37.
Annual equivalent cost - S 50
Annual nel monetary benefits - S5 37 - 60 » S4 87
Payback period (assuming 7H% interest) - 10 years
Table C 7. Example Calculation For Dishwasher.
89
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Appendix D
Water Conservation and Flow Reduction Bibliography:
Selected References Organized by Subject t* i- * .
L Water Conservation and Flow Reduction Mea-
sures (descriptions and evaluations of available
water conservation and Dow reduction measures
including structural economic, legal/institutional
and educational measures).1 , - . .,
California Department of Water Resources. 1978 A
Pilot Water Conservation Program - Final
Report. Appendices G (Device Testing) and H
(Device Selection). Bulletin No 191 Sacramento.
California
Feldman. Stephea 1977 A Handbook of Water
Conservation Devices. Graduate School of
Geography, Clark University. Worcester.
Massachusetts
Flack. Ernest J. Wade P. Weakley. and Duane W.
Hill 1977 Achieving Urban Water Conservationi
A Handbook. Colorado Water Resources
Research Institute. Colorado State University. Fort
Collins, Colorado
Hopp, Wallace Joha October 1979. Cost-Effective-
ness of Household Water Conservation in
Municipal Water Use Strategies. Center lor
Development Technology, Department of
Technology and Urban Human Affairs.
Washington University Saint Louis, Missouri.
Milne, Murray March 1976. Residential Water Con-
servation California Water Resources Center.
Report No 35 University of California at Davis.
Nelsoa John Olat March 1977. North Marin's Little
Compendium of Water-Saving Ideas. North
Marin County Water District Novato, California
2. COM Studies (documented results and
descriptions of regional or community conserve
tion programs)
California Department of Water Resources. 1978 A
Pilot Water Conservation Program. Bulletin No.
19L (Including Appendices A F> Sacramento,
California
California Department of Water Resources.
September 1979. "22 Months Later the Oak Park
Retrofit Program Still a Success." District Report.
Sacramento, California
Deline, M, ed October 1978 Water Conservation
in Municipally Supplied Areas. Great Lakes
Basin Water Conservation Plan - Revised Draft.
Ann Arbor, Michigan
US, Depailment of Energy. 1980. The Low Cost/No
Cost Energy Conservation Program in New
England. An Evaluation Prepared by Boo:: Allen
& Hamilton for US. DOE Market Development
Branca Contract No. AM01-8OCS21366.
Washington DC (Program included distribution of
plastic shower flow restrictors)
Washington Suburban Sanitary Commission.
February 1973 Final and Comprehensive Report
Cabin John Drainage Basin Water-Saving'
Customer Education and Appliance lest Pro-
gram. Hyattsville, Maryland. ' ' ,
\ i i^ ! ,
Washington Suburban Sanitary Commission
(WSSC> November 1974 Final and Comprehen-
sive Report - Washington Suburban Sanitary
Commission's Water Conservation/Wastewater
Reduction/Customer Education and Behavioral
Change Program. Hyattsville. Maryland.
3. Technical Background of Wastewater
Treatment Operations and Flow Reduction
Effects.
Davis. John A and Taras A Bursztynsky. 198O.
"Effects of Water Conservation on Municipal
Wastewater Treatment Facilities" Journal WPCF,
VoL 5Z No 4
DeZellar. Jeffrey T and Walter J Maier 198O
"Effects of Water Conservation on Sanitary Sewers
and Wastewater Treatment Plants." Journal WPCF,
VoL 52 No 1 January. 198O
Fair. Gordon Maskew and John Charles Geyer
1954 Water Supply and Wastewater Disposal
John Wiley and Sons, Inc. New York, New York,
Koyasako. Jimmy & 198O Effects of Water Conser-
vation Induced Wastewater Flow Reduction A
Perspective. Prepared for US. EPA. Wastewater
Research Division Cincinnati. Ohio
Metcall & Eddy, Inc. 1979 Wastewater
Engineering! Treatment, Disposal, Reuse.
McGraw Hill Book Company, Inc.
4 Comprehensive Overviews*
California Department of Water Resources
January 1976 Proceedings! An Urban Water Con-
servation Conference. Los Angeles. California
California Department of Water Resources May
1976. Water Conservation in California Bulletin
No. 198. Saciarr.ento California
California G voirtoi's Of/ice of Emergency
Services May >77? Coriununlty Water
Management /or the brought and Beyond A
Handbook for Local Government Sacramento,
California
McGhee. Ronnie. Mary Reardon and Arleen
Shulman. eds 1978. Readings in Water Conserva-
tion National Association oi Counties Research.
Inc. .....
i,
Preceding page blank
<*«. .* j
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Metcall & Eddy. Inc May 1976 Water Savings.
Prepared lor the Santa Clara Valley Water District
Palo Alto. California
Pennsylvania State University July 1975
Proceedings - Conference on Water Conserva-
tion and Sewage Flow Reduction with Water-
Saving Devices. University Park. Pennsylvania
U S Army Corps ot Engineers, Institute lor Water
Resources. April 1979 The Role of Water Conser-
vation in Water Supply Planning Prepared by
Baumann et al. Southern Illinois University
Contract Report 79-2 Fort Belvoir. Virginia
US EPA. 1979 Proceedings. National Conference
on Water Conservation & Municipal Wastewater
Flow Reduction Held in Chicago, Illinois.
November 197& Prepared by Enviro Control Inc.
lor EPA Ollice of Water Program Operations
Contract No 68-O3-2674. Washingtoa DC
US EPA 1979 Water Supply-Wastewater
Treatment Coordination Study Prepared lor US
EPA. Office ol Drinking Water by INTASA Inc
Contract No 68-O1-5O33. Washington DC
US EPA 198O Guidelines for Water Reuse.
Prepared by Camp Dresser and McKee. Inc lor
US EPA, Wastewater Research Dlvlsioa Contract
No. 68-O3-2686 Cincinnati Ohio
5. Annotated Bibliographies.
US. Army Corps ol Engineers Institute lor Water
Resources April 1979. An Annotated Bibliography
on Water Conservation Prepared by Planning
and Management Consultants, Ltd Contract No
DACW72-78-M-O752 Fort Belvoir, Virginia
US EPA. March I960. Residential Water Conserva-
tion! An Annotated Bibliography. Prepared for
the US Department of Housing and Urban
Development by Pabon. Sims, Smith and
Associates. Inc Washingtoa DC
6. EE& Construction Grants Program. - '
US EPA September 27.197a "Municipal
Wastewater Treatment Works Construction Grants
Program" (4O CFR Part 35. Subpart E). Federal
Register Washingtoa DC
US EPA January, 1979 Municipal Wastewater
Management - Citizens Guide to Facility Plan-
ning Prepared by the Conservation Foundation
lor the Oilice of Water Program Operations
Washingtoa D C Clem L Rastotter, ed.
US EPA January 1979 Municipal Wastewater
Management - Public Involvement Activities
Guide. Prepared by the Conservation Foundation
for the Office of Water Program Operations
Washingtoa DC Clem L Rostotter, ed.
US EPA February 16,1979 "State and Local
Assistance, Giants for Construction of Treatment
Works" (4O CFR Part 35, Subpart E> Federal
Register (Regulations on Public Participation in
the Municipal Wastewater Treatment Works Con
struction Grants Program Carried Out Under the
Clean Water Act> Washingtoa DC
7. Infiltration/Inflow Analysis.
Conklia GF and PW Lewis 198O Evaluation of
Infiltration/Inflow Program, Final Report US
EPA, Project No 68-O1-4913. Washingtoa DC
US EPA March. 1978. "Infiltration/Inflow Program
Guidance." Construction Grants Program
Requirements Memorandum (PRM) No 78-1O
Washingtoa DC
US. EPA December. 1975 Handbook for Sewer
System Evaluation and Rehabilitation (MCD-19)
EPA Report No 43O/9-75-O21. Washingtoa DC
US. EPA March. 1974 Guidance for Sewer System
Evaluation. EPA Report No 52O/9-74-O18
Washingtoa DC
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