Agenda packet — Corona City Council, June 17, 2026 (part 12 of 26)

Target ILI Range

1.0 - 3.0
>3.0 -5.0
>5.0 - 8.0
Greater than 8.0
Less than 1.0
Water resources are believed to be sufficient to meet long-term needs, but demand management interventions (leakage management, water conservation) are included in the long-term planning Water resources are plentiful, reliable, and easily extracted.

Although operational and financial considerations may allow a long-term ILI greater than 8.0, such a level of leakage is not an effective utilization of water as a resource. Setting a target level greater than 8.0 - other than as an incremental goal to a smaller long-term target - is discouraged.If the calculated Infrastructure Leakage Index (ILI) value for your system is 1.0 or less, two possibilities exist. a) you are maintaining your leakage at low levels in a class with the top worldwide performers in leakage control. b) A portion of your data may be flawed, causing your losses to be greatly understated. This is likely if you calculate a low ILI value but do not employ extensive leakage control practices in your operations. In such cases it is beneficial to validate the data by performing field measurements to confirm the accuracy of production and customer meters, or to identify any other potential sources of error in the data. Water resources can be developed or purchased at reasonable expense; periodic water rate increases can be feasibly imposed and are tolerated by the customer population.Cost to purchase or obtain/treat water is low, as are rates charged to customers.

Existing water supply infrastructure capability is sufficient to meet long-term demand as long as reasonable leakage management controls are in place.Superior reliability, capacity and integrity of the water supply infrastructure make it relatively immune to supply shortages.

Financial Considerations
Water resources are costly to develop or purchase; ability to increase revenues via water rates is greatly limited because of regulation or low ratepayer affordability.

Water Resources Considerations
Available resources are greatly limited and are very difficult and/or environmentally unsound to develop.

Operational Considerations
Operating with system leakage above this level would require expansion of existing infrastructure and/or additional water resources to meet the demand.

General Guidelines for Setting a Target ILI
(without doing a full economic analysis of leakage control options) Once data have been entered into the Reporting Worksheet, the performance indicators are automatically calculated. How does a water utility operator know how well his or her system is performing? The AWWA Water Loss Control Committee provided the following table to assist water utilities is gauging an approximate Infrastructure Leakage Index (ILI) that is appropriate for their water system and local conditions. The lower the amount of leakage and real losses that exist in the system, then the lower the ILI value will be.

Note: this table offers an approximate guideline for leakage reduction target-setting. The best means of setting such targets include performing an economic assessment of various loss control methods. However, this table is useful if such an assessment is not possible.

AWWA Free Water Audit Software v5.0 Loss Control Planning 22

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Water Audit Report for:

Reporting Year: 18/19
Data Validity Score: 63
Functional Focus
Area
Audit Data Collection
Short-term loss control
Long-term loss control
Target-setting
Benchmarking
AWWA Free Water Audit Software:

Determining Water Loss Standing
Preliminary Comparisons - can
begin to rely upon the
Infrastructure Leakage Index (ILI)
for performance comparisons for
real losses (see below table)
Performance Benchmarking - ILI
is meaningful in comparing real
loss standing
Identify Best Practices/ Best in
class - the ILI is very reliable as a
real loss performance indicator
for best in class service
For validity scores of 50 or below, the shaded blocks should not be focus areas until better data validity is achieved.

Research information on leak
detection programs. Begin
flowcharting analysis of customer
billing system
Level II (26-50) Level V (91-100)
Analyze business process for
customer metering and billing
functions and water supply
operations. Identify data gaps.

Stay abreast of improvements in
metering, meter reading, billing,
leakage management and
infrastructure rehabilitation
Conduct loss assessment
investigations on a sample
portion of the system: customer
meter testing, leak survey,
unauthorized consumption, etc.

Begin to assemble economic
business case for long-term
needs based upon improved data
becoming available through the
water audit process.

Conduct detailed planning,
budgeting and launch of
comprehensive improvements for
metering, billing or infrastructure
management
Continue incremental
improvements in short-term and
long-term loss control
interventions
Establish long-term apparent and
real loss reduction goals (+10
year horizon)
Establish mid-range (5 year
horizon) apparent and real loss
reduction goals
City of Corona (3310037)
7/2018 - 6/2019
Water Loss Control Planning Guide
Establish/revise policies and
procedures for data collection
Refine data collection practices
and establish as routine business
process
Annual water audit is a reliable
gauge of year-to-year water
efficiency standing
Level III (51-70) Level IV (71-90)
Water Audit Data Validity Level / Score
Level I (0-25)
American Water Works Association.

WAS v5.0
AWWA Free Water Audit Software v5.0 Loss Control Planning 1

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Target ILI Range

Financial Considerations
Water resources are costly to develop or purchase; ability to increase revenues via water rates is greatly limited because of regulation or low ratepayer affordability.

Water Resources Considerations
Available resources are greatly limited and are very difficult and/or environmentally unsound to develop.

Operational Considerations
Operating with system leakage above this level would require expansion of existing infrastructure and/or additional water resources to meet the demand.

AWWA Free Water Audit Software v5.0 Loss Control Planning 2

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Water Audit Report for:

Reporting Year:

All volumes to be entered as: ACRE-FEET PER YEAR
Master Meter and Supply Error Adjustments
WATER SUPPLIED Pcnt: Value:

Volume from own sources: 7 29,513.352 acre-ft/yr 8 acre-ft/yr Water imported: 7 1,239.222 acre-ft/yr 9 acre-ft/yr
Water exported: 7 556.864 acre-ft/yr 9 acre-ft/yr
Enter negative % or value for under-registration
WATER SUPPLIED: 30,195.710 acre-ft/yr Enter positive % or value for over-registration .

AUTHORIZED CONSUMPTION
Billed metered: 7 28,647.940 acre-ft/yr
Billed unmetered: n/a acre-ft/yr
Unbilled metered: 8 62.440 acre-ft/yr Pcnt: Value:

Unbilled unmetered: 377.446 acre-ft/yr 1.25% 24061 acre-ft/yr AUTHORIZED CONSUMPTION: 29,087.826 acre-ft/yr
WATER LOSSES (Water Supplied - Authorized Consumption) 1,107.884 acre-ft/yr Apparent Losses Pcnt: Value:

Unauthorized consumption: 75.489 acre-ft/yr 0.25% acre-ft/yr Customer metering inaccuracies: 5 585.926 acre-ft/yr 2.00% acre-ft/yr Systematic data handling errors: 71.620 acre-ft/yr 0.25% acre-ft/yr Apparent Losses: 733.035 acre-ft/yr
Real Losses (Current Annual Real Losses or CARL)
Real Losses = Water Losses - Apparent Losses: 374.848 acre-ft/yr WATER LOSSES: 1,107.884 acre-ft/yr

NON-REVENUE WATER
NON-REVENUE WATER: 1,547.770 acre-ft/yr
= Water Losses + Unbilled Metered + Unbilled Unmetered

SYSTEM DATA
Length of mains: 8 841.0 miles
Number of active AND inactive service connections: 7 44,884 Service connection density: 53 conn./mile main
Yes
Average length of customer service line: ft
Average operating pressure: 8 93.6 psi

COST DATA
Total annual cost of operating water system: 10 $44,245,485 $/Year Customer retail unit cost (applied to Apparent Losses): 10 $2.46 Variable production cost (applied to Real Losses): 5 $648.88 $/acre-ft WATER AUDIT DATA VALIDITY SCORE:

PRIORITY AREAS FOR ATTENTION:
1: Volume from own sources
2: Customer metering inaccuracies
3: Variable production cost (applied to Real Losses)
Average length of customer service line has been set to zero and a data grading score of 10 has been applied Are customer meters typically located at the curbstop or property line? AWWA Free Water Audit Software:

Reporting Worksheet
Default option selected for Unbilled unmetered - a grading of 5 is applied but not displayed 19/20 7/2019 - 6/2020
City of Corona (3310037)
*** YOUR SCORE IS: 71 out of 100 ***
A weighted scale for the components of consumption and water loss is included in the calculation of the Water Audit Data Validity Score Default option selected for Systematic data handling errors - a grading of 5 is applied but not displayed Based on the information provided, audit accuracy can be improved by addressing the following components:
$/100 cubic feet (ccf)
<----------- Enter grading in column 'E' and 'J' ----------> Default option selected for unauthorized consumption - a grading of 5 is applied but not displayed ?
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Please enter data in the white cells below. Where available, metered values should be used; if metered values are unavailable please estimate a value. Indicate your confidence in the accuracy of the input data by grading each component (n/a or 1-10) using the drop-down list to the left of the input cell. Hover the mouse over the cell to obtain a description of the grades ?
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(length of service line, beyond the property boundary,
that is the responsibility of the utility)
Use buttons to select
percentage of water supplied
OR
value
Click here: ?
for help using option
buttons below
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+
+ Click to add a comment
WAS v5.0
+
+
+
+
+
+
American Water Works Association.
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+
+
+
+
+
+
+
+
+
+
+
+
+ Use Customer Retail Unit Cost to value real losses
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To select the correct data grading for each input, determine the highest grade where the utility meets or exceeds all criteria for that grade and all grades below it.

AWWA Free Water Audit Software v5.0 Reporting Worksheet 2

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5 Name of Contact Person: All audit data are entered on the Reporting Worksheet Email Address: Value can be entered by user
Telephone | Ext.: 951 736-2265 Value calculated based on input data Name of City / Utility: These cells contain recommended default values City/Town/Municipality:

State / Province: Pcnt: Value:

Country: 0.25%
Year: 19/20 Financial Year
Start Date: 07/2019 Enter MM/YYYY numeric format
End Date: 06/2020 Enter MM/YYYY numeric format
Audit Preparation Date: 9/10/2020
Volume Reporting Units:

PWSID / Other ID:

If you have questions or comments regarding the software please contact us via email at: [email protected] AWWA Free Water Audit Software v5.0
City of Corona
The following worksheets are available by clicking the buttons below or selecting the tabs along the bottom of the page Corona
[email protected]
Auditors are strongly encouraged to refer to the most current edition of AWWA M36 Manual for Water Audits for detailed guidance on the water auditing process and targetting loss reduction levels This spreadsheet-based water audit tool is designed to help quantify and track water losses associated with water distribution systems and identify areas for improved efficiency and cost recovery. It provides a "top-down" summary water audit format, and is not meant to take the place of a full-scale, comprehensive water audit format. 3310037
US
Use of Option
(Radio) Buttons:

The spreadsheet contains several separate worksheets. Sheets can be accessed using the tabs towards the bottom of the screen, or by clicking the buttons below.

Stacy Joyce
Acre-feet
Please begin by providing the following information The following guidance will help you complete the Audit California (CA)
American Water Works Association Copyright © 2014, All Rights Reserved.

Select the default percentage
by choosing the option button
on the left
To enter a value, choose
this button and enter a
value in the cell to the right
Instructions
The current sheet.

Enter contact
information and basic
audit details (year,
units etc)
Performance
Indicators
Review the
performance
indicators to evaluate
the results of the audit
Comments
Enter comments to
explain how values
were calculated or to
document data
sources
Water Balance
The values entered in
the Reporting
Worksheet are used to
populate the Water
Balance
Dashboard
A graphical summary
of the water balance
and Non-Revenue
Water components
Grading Matrix
Presents the possible
grading options for
each input component
of the audit
Service Connection
Diagram
Diagrams depicting
possible customer
service connection line
configurations
Acknowledgements
Acknowledgements for
the AWWA Free Water
Audit Software v5.0
Loss Control
Planning
Use this sheet to
interpret the results of
the audit validity
score and
performance
indicators
Definitions
Use this sheet to
understand the terms
used in the audit
process
Example Audits
Reporting Worksheet
and Performance
Indicators examples
are shown for two
validated audits
Reporting Worksheet
Enter the required data
on this worksheet to
calculate the water
balance and data grading
AWWA Free Water Audit Software v5.0 Instructions 1

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Water Audit Report for: City of Corona (3310037)
Reporting Year:

System Attributes:

Apparent Losses: 733.035 acre-ft/yr
+ Real Losses: 374.848 acre-ft/yr
= Water Losses: 1,107.884 acre-ft/yr
Unavoidable Annual Real Losses (UARL): 1,183.09 acre-ft/yr Annual cost of Apparent Losses: $785,503
Annual cost of Real Losses: $243,232 Valued at Variable Production Cost Performance Indicators:

Non-revenue water as percent by volume of Water Supplied: 5.1% Non-revenue water as percent by cost of operating system: 3.0% Real Losses valued at Variable Production Cost Apparent Losses per service connection per day: 14.58 gallons/connection/day Real Losses per service connection per day: 7.46 gallons/connection/day Real Losses per length of main per day*: N/A
Real Losses per service connection per day per psi pressure: 0.08 gallons/connection/day/psi From Above, Real Losses = Current Annual Real Losses (CARL): 374.85 acre-feet/year

0.32 * This performance indicator applies for systems with a low service connection density of less than 32 service connections/mile of pipeline Infrastructure Leakage Index (ILI) [CARL/UARL]:
19/20 7/2019 - 6/2020
Return to Reporting Worksheet to change this assumpiton AWWA Free Water Audit Software:

System Attributes and Performance Indicators
*** YOUR WATER AUDIT DATA VALIDITY SCORE IS: 71 out of 100 *** ?
?
American Water Works Association.

WAS v5.0
Financial:

Operational Efficiency:

AWWA Free Water Audit Software v5.0 Performance Indicators 3 Page 1659 of 3356 AWWA Free Water Audit Software:

Customer Service Line Diagrams
Average Length of Customer
Service Line
The three figures shown on this
worksheet display the
assignment of the Average
Length of Customer Service
Line, Lp, for the three most
common piping configurations.

Figure 1 shows the
configuration of the water meter
outside of the customer building
next to the curb stop valve. In
this configuration Lp = 0 since
the distance between the curb
stop and the customer metering
point is essentially zero.

Figure 2 shows the
configuration of the customer
water meter located inside the
customer building, where Lp is
the distance from the curb stop
to the water meter.

Figure 3 shows the
configuration of an unmetered
customer building , where Lp is
the distance from the curb stop
to the first point of customer
water consumption, or, more
simply, the building line.

In any water system the Lp will
vary notably in a community of
different structures, therefore the
average Lp value is used and
this should be approximated or
calculated if a sample of service
line measurements has been
gathered.

Figure 1
Figure 2
Figure 3
American Water Works Association.

WAS v5.0
Click for more
information
AWWA Free Water Audit Software v5.0 Service Connection Diagram 9

Page 1660 of 3356 ends

Item Name
Apparent
Losses

AUTHORIZED

CONSUMPTION
Average length of
customer service
line
Average operating
pressure
Billed Authorized
Consumption
Billed metered
consumption
Billed unmetered
consumption
= unauthorized consumption + customer metering inaccuracies + systematic data handling errors Apparent Losses include all types of inaccuracies associated with customer metering (worn meters as well as improperly sized meters or wrong type of meter for the water usage profile) as well as systematic data handling errors (meter reading, billing, archiving and reporting), plus unauthorized consumption (theft or illegal use).

NOTE: Over-estimation of Apparent Losses results in under-estimation of Real Losses. Under-estimation of Apparent Losses results in over-estimation of Real Losses.

All metered consumption which is billed to retail customers, including all groups of customers such as domestic, commercial, industrial or institutional. It does NOT include water supplied to neighboring utilities (water exported) which is metered and billed. Be sure to subtract any consumption for exported water sales that may be included in these billing roles. Water supplied as exports to neighboring water utilities should be included only in the Water Exported component. The metered consumption data can be taken directly from billing records for the water audit period. The accuracy of yearly metered consumption data can be refined by including an adjustment to account for customer meter reading lag time since not all customer meters are read on the same day of the meter reading period. However additional analysis is necessary to determine the lag time adjustment value, which may or may not be significant.

All billed consumption which is calculated based on estimates or norms from water usage sites that have been determined by utility policy to be left unmetered.

This is typically a very small component in systems that maintain a policy to meter their customer population. However, this quantity can be the key consumption component in utilities that have not adopted a universal metering policy. This component should NOT include any water that is supplied to neighboring utilities (water exported) which is unmetered but billed. Water supplied as exports to neighboring water utilities should be included only in the Water Exported component.

AWWA Free Water Audit Software:

Definitions
Description
= billed water exported + billed metered + billed unmetered + unbilled metered + unbilled unmetered consumption The volume of metered and/or unmetered water taken by registered customers, the water utility's own uses, and uses of others who are implicitly or explicitly authorized to do so by the water utility; for residential, commercial, industrial and public-minded purposes.

Typical retail customers' consumption is tabulated usually from established customer accounts as billed metered consumption, or - for unmetered customers - billed unmetered consumption. These types of consumption, along with billed water exported, provide revenue potential for the water utility. Be certain to tabulate the water exported volume as a separate component and do not "double-count" it by including in the billed metered consumption component as well as the water exported component.

Unbilled authorized consumption occurs typically in non-account uses, including water for fire fighting and training, flushing of water mains and sewers, street cleaning, watering of municipal gardens, public fountains, or similar public-minded uses. Occasionally these uses may be metered and billed (or charged a flat fee), but usually they are unmetered and unbilled. In the latter case, the water auditor may use a default value to estimate this quantity, or implement procedures for the reliable quantification of these uses. This starts with documenting usage events as they occur and estimating the amount of water used in each event. (See Unbilled unmetered consumption)
This is the average length of customer service line, Lp, that is owned and maintained by the customer; from the point of ownership transfer to the customer water meter, or building line (if unmetered). The quantity is one of the data inputs for the calculation of Unavoidable Annual Real Losses (UARL), which serves as the denominator of the performance indicator: Infrastructure Leakage Index (ILI). The value of Lp is multiplied by the number of customer service connections to obtain a total length of customer owned piping in the system. The purpose of this parameter is to account for the unmetered service line infrastructure that is the responsibility of the customer for arranging repairs of leaks that occur on their lines. In many cases leak repairs arranged by customers take longer to be executed than leak repairs arranged by the water utility on utility-maintained piping. Leaks run longer - and lose more water - on customer-owned service piping, than utility owned piping.

If the customer water meter exists near the ownership transfer point (usually the curb stop located between the water main and the customer premises) this distance is zero because the meter and transfer point are the same. This is the often encountered configuration of customer water meters located in an underground meter box or "pit" outside of the customer's building. The Free Water Audit Software asks a "Yes/No" question about the meter at this location. If the auditor selects "Yes" then this distance is set to zero and the data grading score for this component is set to 10.

If water meters are typically located inside the customer premise/building, or properties are unmetered, it is up to the water auditor to estimate a system-wide average Lp length based upon the various customer land parcel sizes and building locations in the service area. Lp will be a shorter length in areas of high density housing, and a longer length in areas of low density housing and varied commercial and industrial buildings. General parcel demographics should be employed to obtain a composite average Lp length for the entire system.

Refer to the "Service Connection Diagram" worksheet for a depiction of the service line/metering configurations that typically exist in water utilities. This worksheet gives guidance on the determination of the Average Length, Lp, for each configuration.

This is the average pressure in the distribution system that is the subject of the water audit. Many water utilities have a calibrated hydraulic model of their water distribution system. For these utilities, the hydraulic model can be utilized to obtain a very accurate quantity of average pressure. In the absence of a hydraulic model, the average pressure may be approximated by obtaining readings of static water pressure from a representative sample of fire hydrants or other system access points evenly located across the system. A weighted average of the pressure can be assembled; but be sure to take into account the elevation of the fire hydrants, which typically exist several feet higher than the level of buried water pipelines. If the water utility is compiling the water audit for the first time, the average pressure can be approximated, but with a low data grading. In subsequent years of auditing, effort should be made to improve the accuracy of the average pressure quantity. This will then qualify the value for a higher data grading.

All consumption that is billed and authorized by the utility. This may include both metered and unmetered consumption. See "Authorized Consumption" for more information.

A
WAS v5.0
American Water Works Association.

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AWWA Free Water Audit Software v5.0 Page 1661 of 3356 Definitions 10 Item Name Description
A
Customer
metering
inaccuracies
Customer retail
unit cost
Infrastructure
Leakage Index
(ILI)
Length of mains

NON-REVENUE
WATER
Number of active
AND inactive
service
connections
Real Losses
Revenue Water
Service
Connection
Density =number of customer service connections / length of mains Length of all pipelines (except service connections) in the system starting from the point of system input metering (for example at the outlet of the treatment plant). It is also recommended to include in this measure the total length of fire hydrant lead pipe. Hydrant lead pipe is the pipe branching from the water main to the fire hydrant. Fire hydrant leads are typically of a sufficiently large size that is more representative of a pipeline than a service connection. The average length of hydrant leads across the entire system can be assumed if not known, and multiplied by the number of fire hydrants in the system, which can also be assumed if not known. This value can then be added to the total pipeline length. Total length of mains can therefore be calculated as:

Length of Mains, miles = (total pipeline length, miles) + [ {(average fire hydrant lead length, ft) x (number of fire hydrants)} / 5,280 ft/mile ] or
Length of Mains, kilometres = (total pipeline length, kilometres) + [ {(average fire hydrant lead length, metres) x (number of fire hydrants)} / 1,000 metres/kilometre ]
Those components of System Input Volume that are billed and have the potential to produce revenue.

Physical water losses from the pressurized system (water mains and customer service connections) and the utility’s storage tanks, up to the point of customer consumption. In metered systems this is the customer meter, in unmetered situations this is the first point of consumption (stop tap/tap) within the property. The annual volume lost through all types of leaks, breaks and overflows depends on frequencies, flow rates, and average duration of individual leaks, breaks and overflows.
= Apparent Losses + Real Losses + Unbilled Metered Consumption + Unbilled Unmetered Consumption. This is water which does not provide revenue potential to the utility.

Number of customer service connections, extending from the water main to supply water to a customer. Please note that this includes the actual number of distinct piping connections, including fire connections, whether active or inactive. This may differ substantially from the number of customers (or number of accounts). Note: this number does not include the pipeline leads to fire hydrants - the total length of piping supplying fire hyrants should be included in the "Length of mains" parameter.

Apparent water losses caused by the collective under-registration of customer water meters. Many customer water meters gradually wear as large cumulative volumes of water are passed through them over time. This causes the meters to under-register the flow of water. This occurrence is common with smaller residential meters of sizes 5/8-inch and 3/4 inch after they have registered very large cumulative volumes of water, which generally occurs only after periods of years. For meters sized 1-inch and larger - typical of multi-unit residential, commercial and industrial accounts - meter under-registration can occur from wear or from the improper application of the meter; i.e. installing the wrong type of meter or the wrong size of meter, for the flow pattern (profile) of the consumer. For instance, many larger meters have reduced accuracy at low flows. If an oversized meter is installed, most of the time the routine flow will occur in the low flow range of the meter, and a significant portion of it may not be registered. It is important to properly select and install all meters, but particularly large customer meters, size 1-inch and larger.

The auditor has two options for entering data for this component of the audit. The auditor can enter a percentage under-registration (typically an estimated value), this will apply the selected percentage to the two categories of metered consumption to determine the volume of water not recorded due to customer meter inaccuracy. Note that this percentage is a composite average inaccuracy for all customer meters in the entire meter population. The percentage will be multiplied by the sum of the volumes in the Billed Metered and Unbilled Metered components. Alternatively, if the auditor has substantial data from meter testing activities, he or she can calculate their own loss volumes, and this volume may be entered directly.

Note that a value of zero will be accepted but an alert will appear asking if the customer population is unmetered. Since all metered systems have some degree of inaccuracy, a positive value should be entered. A value of zero in this component is valid only if the water utility does not meter its customer population.

The Customer Retail Unit Cost represents the charge that customers pay for water service. This unit cost is applied routinely to the components of Apparent Loss, since these losses represent water reaching customers but not (fully) paid for. Since most water utilities have a rate structure that includes a variety of different costs based upon class of customer, a weighted average of individual costs and number of customer accounts in each class can be calculated to determine a single composite cost that should be entered into this cell. Finally, the weighted average cost should also include additional charges for sewer, storm water or biosolids processing, but only if these charges are based upon the volume of potable water consumed.

For water utilities in regions with limited water resources and a questionable ability to meet the drinking water demands in the future, the Customer Retail Unit Cost might also be applied to value the Real Losses; instead of applying the Variable Production Cost to Real Losses. In this way, it is assumed that every unit volume of leakage reduced by leakage management activities will be sold to a customer.

Note: the Free Water Audit Software allows the user to select the units that are charged to customers (either $/1,000 gallons, $/hundred cubic feet, or $/1,000 litres) and automatically converts these units to the units that appear in the "WATER SUPPLIED" box. The monetary units are United States dollars, $.

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AWWA Free Water Audit Software v5.0 Page 1662 of 3356 Definitions 11 Item Name Description
A
Systematic data
handling errors
Total annual cost
of operating the
water system
Unauthorized
consumption
Unbilled
Authorized
Consumption
Unavoidable
Annual Real
Losses (UARL)
UARL (gallons)=(5.41Lm + 0.15Nc + 7.5Lc) xP,
or
UARL (litres)=(18.0Lm + 0.8Nc + 25.0Lc) xP
where:

Lm = length of mains (miles or kilometres)
Nc = number of customer service connections
Lp = the average distance of customer service connection piping (feet or metres) (see the Worksheet "Service Connection Diagram" for guidance on deterring the value of Lp) Lc = total length of customer service connection piping (miles or km) Lc = Nc X Lp (miles or kilometres)
P = Pressure (psi or metres)
The UARL is a theoretical reference value representing the technical low limit of leakage that could be achieved if all of today's best technology could be successfully applied. It is a key variable in the calculation of the Infrastructure Leakage Index (ILI). Striving to reduce system leakage to a level close to the UARL is usually not needed unless the water supply is unusually expensive, scarce or both.

NOTE: The UARL calculation has not yet been proven as fully valid for very small, or low pressure water distribution systems. If, in gallons:
(Lm x 32) + Nc < 3000 or
P <35psi
in litres:
(Lm x 20) + Nc < 3000 or
P < 25m
then the calculated UARL value may not be valid. The software does not display a value of UARL or ILI if either of these conditions is true.

All consumption that is unbilled, but still authorized by the utility. This includes Unbilled Metered Consumption + Unbilled Unmetered Consumption. See "Authorized Consumption" for more information. For Unbilled Unmetered Consumption, the Free Water Audit Software provides the auditor the option to select a default value if they have not audited unmetered activities in detail. The default calculates a volume that is 1.25% of the Water Supplied volume. If the auditor has carefully audited the various unbilled, unmetered, authorized uses of water, and has established reliable estimates of this collective volume, then he or she may enter the volume directly for this component, and not use the default value.

Systematic Data Handling Errors result in a direct loss of revenue potential. Water utilities can find "lost" revenue by keying on this component.

Utilities typically measure water consumption registered by water meters at customer premises. The meter should be read routinely (ex: monthly) and the data transferred to the Customer Billing System, which generates and sends a bill to the customer. Data Transfer Errors result in the consumption value being less than the actual consumption, creating an apparent loss. Such error might occur from illegible and mis-recorded hand-written readings compiled by meter readers, inputting an incorrect meter register unit conversion factor in the automatic meter reading equipment, or a variety of similar errors.

Close auditing of the permitting, metering, meter reading, billing and reporting processes of the water consumption data trail can uncover data management gaps that create volumes of systematic data handling error. Utilities should routinely analyze customer billing records to detect data anomalies and quantify these losses. For example, a billing account that registers zero consumption for two or more billing cycles should be checked to explain why usage has seemingly halted. Given the revenue loss impacts of these losses, water utilities are well-justified in providing continuous oversight and timely correction of data transfer errors & data handling errors.

If the water auditor has not yet gathered detailed data or assessment of systematic data handling error, it is recommended that the auditor apply the default value of 0.25% of the the Billed Authorized Consumption volume. However, if the auditor has investigated the billing system and its controls, and has well validated data that indicates the volume from systematic data handling error is substantially higher or lower than that generated by the default value, then the auditor should enter a quantity that was derived from the utility investigations and select an appropriate grading. Note: negative values are not allowed for this audit component. If the auditor enters zero for this component then a grading of 1 will be automatically assigned.

Includes water illegally withdrawn from fire hydrants, illegal connections, bypasses to customer consumption meters, or tampering with metering or meter reading equipment; as well as any other ways to receive water while thwarting the water utility's ability to collect revenue for the water. Unauthorized consumption results in uncaptured revenue and creates an error that understates customer consumption. In most water utilities this volume is low and, if the water auditor has not yet gathered detailed data for these loss occurrences, it is recommended that the auditor apply a default value of 0.25% of the volume of water supplied. However, if the auditor has investigated unauthorized occurrences, and has well validated data that indicates the volume from unauthorized consumption is substantially higher or lower than that generated by the default value, then the auditor should enter a quantity that was derived from the utility investigations. Note that a value of zero will not be accepted since all water utilities have some volume of unauthorized consumption occurring in their system.

Note: if the auditor selects the default value for unauthorized consumption, a data grading of 5 is automatically assigned, but not displayed on the Reporting Worksheet.

These costs include those for operations, maintenance and any annually incurred costs for long-term upkeep of the drinking water supply and distribution system. It should include the costs of day-to-day upkeep and long-term financing such as repayment of capital bonds for infrastructure expansion or improvement. Typical costs include employee salaries and benefits, materials, equipment, insurance, fees, administrative costs and all other costs that exist to sustain the drinking water supply. Depending upon water utility accounting procedures or regulatory agency requirements, it may be appropriate to include depreciation in the total of this cost. This cost should not include any costs to operate wastewater, biosolids or other systems outside of drinking water.

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AWWA Free Water Audit Software v5.0 Page 1663 of 3356 Definitions 12 Item Name Description
A
Unbilled metered
consumption
Unbilled
unmetered
consumption
Convert From…
Million Gallons (US) = 3.06888329 Acre-feet
Use of Option
Buttons
Variable
production cost
(applied to Real
Losses)
Volume from own
sources
Volume from own
sources: Master
meter and supply
error adjustment
1 The cost to produce and supply the next unit of water (e.g., $/million gallons). This cost is determined by calculating the summed unit costs for ground and surface water treatment and all power used for pumping from the source to the customer. It may also include other miscellaneous unit costs that apply to the production of drinking water. It should also include the unit cost of bulk water purchased as an import if applicable.

It is common to apply this unit cost to the volume of Real Losses. However, if water resources are strained and the ability to meet future drinking water demands is in question, then the water auditor can be justified in applying the Customer Retail Rate to the Real Loss volume, rather than applying the Variable Production Cost.

The Free Water Audit Software applies the Variable Production costs to Real Losses by default. However, the auditor has the option on the Reporting Worksheet to select the Customer Retail Cost as the basis for the Real Loss cost evaluation if the auditor determines that this is warranted.

The volume of water withdrawn (abstracted) from water resources (rivers, lakes, streams, wells, etc) controlled by the water utility, and then treated for potable water distribution. Most water audits are compiled for utility retail water distribution systems, so this volume should reflect the amount of treated drinking water that entered the distribution system. Often the volume of water measured at the effluent of the treatment works is slightly less than the volume measured at the raw water source, since some of the water is used in the treatment process. Thus, it is useful if flows are metered at the effluent of the treatment works. If metering exists only at the raw water source, an adjustment for water used in the treatment process should be included to account for water consumed in treatment operations such as filter backwashing, basin flushing and cleaning, etc. If the audit is conducted for a wholesale water agency that sells untreated water, then this quantity reflects the measure of the raw water, typically metered at the source.

An estimate or measure of the degree of inaccuracy that exists in the master (production) meters measuring the annual Volume from own Sources, and any error in the data trail that exists to collect, store and report the summary production data. This adjustment is a weighted average number that represents the collective error for all master meters for all days of the audit year and any errors identified in the data trail. Meter error can occur in different ways. A meter or meters may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Data error can occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some degree of inaccuracy in master meters and data errors in archival systems are common; thus a value of zero should not be entered. Enter a negative percentage or value for metered data under-registration; or, enter a positive percentage or value for metered data over-registration.

Any kind of Authorized Consumption which is neither billed or metered. This component typically includes water used in activities such as fire fighting, flushing of water mains and sewers, street cleaning, fire flow tests conducted by the water utility, etc. In most water utilities it is a small component which is very often substantially overestimated. It does NOT include water supplied to neighboring utilities (water exported) which is unmetered and unbilled – an unlikely case. This component has many sub-components of water use which are often tedious to identify and quantify. Because of this, and the fact that it is usually a small portion of the water supplied, it is recommended that the auditor apply the default value, which is 1.25% of the Water Supplied volume. Select the default percentage to enter this value.

If the water utility has carefully audited the unbilled, unmetered activities occurring in the system, and has well validated data that gives a value substantially higher or lower than the default volume, then the auditor should enter their own volume. However the default approach is recommended for most water utilities.

Note that a value of zero is not permitted, since all water utilities have some volume of water in this component occurring in their system.

The user may develop an audit based on one of three unit selections:
1) Million Gallons (US)
2) Megalitres (Thousand Cubic Metres)
3) Acre-feet
Once this selection has been made in the instructions sheet, all calculations are made on the basis of the chosen units. Should the user wish to make additional conversions, a unit converter is provided below (use drop down menus to select units from the yellow unit boxes):

Enter Units:

Units and
Conversions
(conversion factor = 3.06888328973723)
Metered consumption which is authorized by the water utility, but, for any reason, is deemed by utility policy to be unbilled. This might for example include metered water consumed by the utility itself in treatment or distribution operations, or metered water provided to civic institutions free of charge. It does not include water supplied to neighboring utilities (water exported) which may be metered but not billed.

Converts to…..

To use the default percent value choose this button To enter a value choose this button and enter the value in the cell to the right NOTE: For Unbilled Unmetered Consumption, Unauthorized Consumption and Systematic Data Handling Errors, a recommended default value can be applied by selecting the Percent option. The default values are based on fixed percentages of Water Supplied or Billed Authorized Consumption and are recommended for use in this audit unless the auditor has well validated data for their system. Default values are shown by purple cells, as shown in the example above.

If a default value is selected, the user does not need to grade the item; a grading value of 5 is automatically applied (however, this grade will not be displayed).

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AWWA Free Water Audit Software v5.0 Page 1664 of 3356 Definitions 13 Item Name Description
A
Water exported
Water exported:

Master meter and
supply error
adjustment
Water imported
Water imported:

Master meter and
supply error
adjustment

WATER LOSSES
= apparent losses + real losses
Water Losses are the difference between Water Supplied and Authorized Consumption. Water losses can be considered as a total volume for the whole system, or for partial systems such as transmission systems, pressure zones or district metered areas (DMA); if one of these configurations are the basis of the water audit.

An estimate or measure of the volume in which the Water Imported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived imported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by underregistering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some level of meter inaccuracy, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived metered data. Thus, a value of zero should not be entered. Enter a negative percentage or value for metered data under-registration; or, enter a positive percentage or value for metered data over-registration. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment.

An estimate or measure of the volume in which the Water Exported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived exported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by underregistering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some degree of error in their metered data, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived data. Thus, a value of zero should not be entered. Enter a negative percentage or value for metered data under-registration; or enter a positive percentage or value for metered data over-registration. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment. Corrections to data gaps or other errors found in the archived data should also be included as a portion of this meter error adjustment.

The Water Imported volume is the bulk water purchased to become part of the Water Supplied volume. Typically this is water purchased from a neighboring water utility or regional water authority, and is metered at the custody transfer point of interconnection between the two water utilities. Usually the meter(s) are owned by the water supplier selling the water to the utility conducting the water audit. The water supplier selling the bulk water usually charges the receiving utility based upon a wholesale water rate.

The Water Exported volume is the bulk water conveyed and sold by the water utility to neighboring water systems that exists outside of their service area.

Typically this water is metered at the custody transfer point of interconnection between the two water utilities. Usually the meter(s) are owned by the water utility that is selling the water: i.e. the exporter. If the water utility who is compiling the annual water audit sells bulk water in this manner, they are an exporter of water.

Note: The Water Exported volume is sold to wholesale customers who are typically charged a wholesale rate that is different than retail rates charged to the retail customers existing within the service area. Many state regulatory agencies require that the Water Exported volume be reported to them as a quantity separate and distinct from the retail customer billed consumption. For these reasons - and others - the Water Exported volume is always quantified separately from Billed Authorized Consumption in the standard water audit. Be certain not to "double-count" this quantity by including it in both the Water Exported box and the Billed Metered Consumption box of the water audit Reporting Worksheet. This volume should be included only in the Water Exported box.

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AWWA Free Water Audit Software v5.0 Page 1665 of 3356 Definitions 14 Water Audit Report for:

Reporting Year: 19/20
Data Validity Score: 71
Functional Focus
Area
Audit Data Collection
Short-term loss control
Long-term loss control
Target-setting
Benchmarking
Target ILI Range

1.0 - 3.0
>3.0 -5.0
>5.0 - 8.0
Greater than 8.0
Less than 1.0
AWWA Free Water Audit Software:

Determining Water Loss Standing
Water resources are believed to be sufficient to meet long-term needs, but demand management interventions (leakage management, water conservation) are included in the long-term planning. Water resources are plentiful, reliable, and easilyextracted.

Existing water supply infrastructure capability is sufficient to meet long-term demand as long as reasonable leakage management controls are in place.Superior reliability, capacity and integrity of thewater supply infrastructure make it relatively immune to supply shortages.

Financial Considerations
Water resources are costly to develop or purchase; ability to increase revenues via water rates is greatly limited because of regulation or low ratepayer affordability.

Water Resources Considerations
Available resources are greatly limited and are
very difficult and/or environmentally unsound to develop.

Operational Considerations
Operating with system leakage above this level would require expansion of existing infrastructure and/or additional water resources to meet the demand.

General Guidelines for Setting a Target ILI
(without doing a full economic analysis of leakage control options) Preliminary Comparisons - can
begin to rely upon the
Infrastructure Leakage Index (ILI)
for performance comparisons for
real losses (see below table)
Performance Benchmarking - ILI
is meaningful in comparing real
loss standing
Identify Best Practices/ Best in
class - the ILI is very reliable as a
real loss performance indicator
for best in class service
Once data have been entered into the Reporting Worksheet, the performance indicators are automatically calculated. How does a water utility operator know how well his or her system is performing? The AWWA Water Loss Control Committee provided the following table to assist water utilities is gauging an approximate Infrastructure Leakage Index (ILI) that is appropriate for their water system and local conditions. The lower the amount of leakage and real losses that exist in the system, then the lower the ILI value will be.

For validity scores of 50 or below, the shaded blocks should not be focus areas until better data validity is achieved.

Begin to assemble economic
business case for long-term
needs based upon improved data
becoming available through the
water audit process.

Conduct detailed planning,
budgeting and launch of
comprehensive improvements for
metering, billing or infrastructure
management
Continue incremental
improvements in short-term and
long-term loss control
interventions
Establish long-term apparent and
real loss reduction goals (+10
year horizon)
Establish mid-range (5 year
horizon) apparent and real loss
reduction goals
City of Corona (3310037)
7/2019 - 6/2020
Water Loss Control Planning Guide
Establish/revise policies and
procedures for data collection
Refine data collection practices
and establish as routine business
process
Annual water audit is a reliable
gauge of year-to-year water
efficiency standing
Level III (51-70) Level IV (71-90)
Water Audit Data Validity Level / Score
Level I (0-25)
American Water Works Association.

WAS v5.0
AWWA Free Water Audit Software v5.0 Loss Control Planning 15

Page 1666 of 3356 ends

AWWA Free Water Audit Software:

Examples of Completed and Validated Audits American Water Works Association.

WAS v5.0
Example Audit 1a:

Example 1a: Million Gallons: Example 1b: Million Gallons: Example 2a: Megalitres:

Reporting Worksheet
Example 2b: Megalitres:

Reporting Worksheet
AWWA Free Water Audit Software v5.0 Page 1667 of 3356 Example Audits 16 Example Audit 1b:

AWWA Free Water Audit Software v5.0 Page 1668 of 3356 Example Audits 17 Example Audit 2a:

AWWA Free Water Audit Software v5.0 Page 1669 of 3356 Example Audits 18 Example Audit 2b:

AWWA Free Water Audit Software v5.0 Page 1670 of 3356 Example Audits 19 DEVELOPED BY: Andrew Chastain-Howley, PG*, MCSM. Black & Veatch Will J. Jernigan, P.E. Cavanaugh & Associates, P.A.George Kunkel, P.E. Philadelphia Water Department Alain Lalonde, P.Eng. Master Meter Canada Inc.

Ralph Y. McCord, P.E. Louisville Water CompanyDavid A. Sayers Delaware River Basin CommissionBrian M. Skeens, P.E. CH2M HILLReinhard Sturm Water Systems Optimization, Inc.John H. Van Arsdel M.E. Simpson Company, Inc.

REFERENCES: - Alegre, H., Hirner, W., Baptista, J. and Parena, R. Performance Indicators for Water Supply Services. IWA Publishing ‘Manual of Best Practice’ Series, 2000. ISBN 1 900222 272- Kunkel, G. et al, 2003. Water Loss Control Committee Report: Applying Worldwide Best Management Practices in Water Loss Control. Journal AWWA, 95:8:65- AWWA Water Audits and Loss Control Programs, M36 Publication, 3 rd Edition, 2009 - Service Connection Diagrams courtesy of Ronnie McKenzie, WRP Pty Ltd.

AWWA Water Audit Software Version 5.0 Developed by the Water Loss Control Committee of the American Water Works Association August, 2014
This software is intended to serve as a basic tool to compile a preliminary, or “top-down”, water audit. It is recommended that users also refer to the current edition of the AWWA M36 Publication, Water Audits and Loss Control Programs, for detailed guidance on compiling a comprehensive, or “bottom-up”, water audit using the same water audit methodology.

AWWA Free Water Audit Software:

WAS v5.0
www.awwa.org
AWWA Free Water Audit Software v5.0 Page 1671 of 3356 Acknowledgements 20 VERSION HISTORY:

Version: Release Date: Number of Worksheets:
v1 2005/ 2006 5
v2 2006 5v3 2007 7
v4 - v4.2 2010 10
v5 2014 12
v4 (and versions 4.x) of the software included a new approach to data grading. The simple "estimated" or "measured" approach was replaced with a more granular scale (typically 1-10) that reflected descriptions of utility practices and served to describe the confidence and accuracy of the input data. Each input value had a corresponding scale fully described in the Grading Matrix tab.

The Grading Matrix also showed the actions required to move to a higher grading score. Grading descriptions were available on the Reporting Worksheet via a pop-up box next to each water audit input. A water audit data validity score is generated (max = 100) and priority areas for attention (to improve audit accuracy) are identified, once a user completes the requied data grading. A service connection diagram was also added to help users understand the impact of customer service line configurations on water losses and how this information should be entered into the water audit software. An acknoweldgements section was also added. Minor bug fixes resulted in the release of versions 4.1 and 4.2. A French language version was also made available for v4.2.In v5, changes were made to the way Water Supplied information is entered into software, with each major component having a corresponding Master Meter Error Adjustment entry (and data grading requirement). This required changes to the data validity score calculation; v5 of the software uses a weighting system that is, in part, proportional to the volume of input components. The Grading Matrix was updated to reflect the new audit inputs and also to include clarifications and additions to the scale descriptions. The appearance of the software was updated in v5 to make the software more user-friendly and several new features were added to provide more feedback to the user. Notably, a dashboard tab has been added to provide more visual feedback on the water audit results and associated costs of Non-Revenue Water. A comments sheet was added to allow the user to track notes, comments and to cite sources used.

Key Features and Developments
The AWWA Water Audit Software was piloted in 2005 (v1.0 beta). The early versions (1.x) of the software restricted data entry to units of Million Gallons per year. For each entry into the audit, users identified whether the input was measured or estimated.

The most significant enhancement in v2 of the software was to allow the user to choose the volumetric units to be used in the audit, Million Gallons or Thousand Cubic Metres (megalitres) per year. Two financial performance indicators were added to provide feedback to the user on the cost of Real and Apparent losses. In v3, the option to report volumetric units in acre-feet was added. Another new feature in v3 was the inclusion of default values for two water audit components (unbilled unmetered and unauthorized consumption). v3 also included two examples of completed audits in units of million gallons and Megalitres. Several checks were added into v3 to provide instant feedback to the user on common data entry problems, in order to help the user complete an accurate water audit.

AWWA Free Water Audit Software v5.0 Page 1672 of 3356 Acknowledgements 21 Water Audit Report for:

Reporting Year: 19/20 7/2019 - 6/2020
Data Validity Score: 71
Water Exported Revenue Water
556.864 556.864
Billed Metered Consumption (water exported is removed) Revenue Water 28,647.940
Own Sources Authorized Consumption 28,647.940 Billed Unmetered Consumption 28,647.940

0.000
29,087.826 Unbilled Metered Consumption

62.440
29,513.352 439.886 Unbilled Unmetered Consumption
377.446
System Input Water Supplied Unauthorized Consumption 1,547.770 30,752.574 Apparent Losses 75.489
30,195.710 733.035 Customer Metering Inaccuracies
585.926
Systematic Data Handling Errors
Water Losses 71.620
Water Imported 1,107.884 Leakage on Transmission and/or Distribution Mains Real Losses Not broken down
1,239.222 374.848 Leakage and Overflows at Utility's Storage Tanks Not broken downLeakage on Service ConnectionsNot broken down AWWA Free Water Audit Software: Water Balance
Non-Revenue Water
(NRW)
Billed Authorized Consumption
Unbilled Authorized Consumption
(Adjusted for known
errors)
Billed Water Exported
City of Corona (3310037)
WAS v5.0
American Water Works Association.

AWWA Free Water Audit Software v5.0 Page 1673 of 3356 Water Balance 6 Water Audit Report for:

Reporting Year: 19/20 Show me the VOLUME of Non-Revenue Water Data Validity Score: 71 Show me the COST of Non-Revenue Water AWWA Free Water Audit Software:

Dashboard
7/2019 - 6/2020
City of Corona (3310037)
0 100,000200,000300,000400,000500,000600,000700,000
Cost $
Total Cost of NRW =$1,314,168
Unbilled metered (valued at Var. Prod. Cost)Unbilled unmetered (valued at Var. Prod. Cost)Unauth. consumptionCust. metering inaccuraciesSyst. data handling errorsReal Losses (valued at Var. Prod. Cost) WAS v5.0
American Water Works Association.

Water ExportedAuthorized ConsumptionWater Losses
0%
10%20%30%40%50%60%70%80%90%
100%
Water ExportedWater ImportedVolume From Own Sources
Real Losses Apparent LossesUnbilled Auth. Cons. Billed Auth. Cons.Water Exported Water ExportedRevenue WaterNon Revenue Water
The graphic below is a visual representation of the
Water Balance with bar heights propotional to the
volume of the audit components
Water Exported Water Supplied
AWWA Free Water Audit Software v5.0 Page 1674 of 3356 Dashboard 7 5 Name of Contact Person: All audit data are entered on the Reporting Worksheet Email Address: Value can be entered by user
Telephone | Ext.: 951 736-2265 Value calculated based on input data Name of City / Utility: These cells contain recommended default values City/Town/Municipality:

State / Province: Pcnt: Value:

Country: 0.25%
Year: 20/21 Financial Year
Start Date: 07/2020 Enter MM/YYYY numeric format
End Date: 06/2021 Enter MM/YYYY numeric format
Audit Preparation Date: 9/14/2021
Volume Reporting Units:

PWSID / Other ID:

If you have questions or comments regarding the software please contact us via email at: [email protected] The spreadsheet contains several separate worksheets. Sheets can be accessed using the tabs towards the bottom of the screen, or by clicking the buttons below.

Stacy Joyce
Acre-feet
Please begin by providing the following information The following guidance will help you complete the Audit California (CA)
AWWA Free Water Audit Software v5.0
City of Corona
The following worksheets are available by clicking the buttons below or selecting the tabs along the bottom of the page Corona
[email protected]
Auditors are strongly encouraged to refer to the most current edition of AWWA M36 Manual for Water Audits for detailed guidance on the water auditing process and targetting loss reduction levels This spreadsheet-based water audit tool is designed to help quantify and track water losses associated with water distribution systems and identify areas for improved efficiency and cost recovery. It provides a "top-down" summary water audit format, and is not meant to take the place of a full-scale, comprehensive water audit format.

CA3310037
US
Use of Option
(Radio) Buttons:

Select the default percentage
by choosing the option button
on the left
To enter a value, choose
this button and enter a
value in the cell to the right
Instructions
The current sheet.

Enter contact
information and basic
audit details (year,
units etc)
Performance
Indicators
Review the
performance
indicators to evaluate
the results of the audit
Comments
Enter comments to
explain how values
were calculated or to
document data sources Water Balance
The values entered in
the Reporting
Worksheet are used
to populate the Water
Balance
Dashboard
A graphical summary of
the water balance and
Non-Revenue Water
components
Grading Matrix
Presents the possible
grading options for
each input component
of the audit
Service Connection
Diagram
Diagrams depicting
possible customer
service connection line
configurations
Acknowledgements
Acknowledgements for
the AWWA Free Water
Audit Software v5.0
Loss Control
Planning
Use this sheet to
interpret the results of
the audit validity score
and performance
indicators
Definitions
Use this sheet to
understand the terms
used in the audit
process
Example Audits
Reporting Worksheet
and Performance
Indicators examples
are shown for two
validated audits
Reporting Worksheet
Enter the required data
on this worksheet to
calculate the water
balance and data grading
AWWA Free Water Audit Software v5.0 Instructions 1

Page 1675 of 3356 ends

AWWA Free Water Audit Software:

Reporting Worksheet
Water Audit Report for: City of Corona (CA3310037)
Reporting Year: 20/21 7/2020 - 6/2021
All volumes to be entered as: ACRE-FEET PER YEAR
Master Meter and Supply Error Adjustments
WATER SUPPLIED <----------- Enter grading in column 'E' and 'J' ----------> Pcnt: Value:

Volume from own sources: 7 31,465.843 acre-ft/yr 8 acre-ft/yr Water imported: 7 1,320.554 acre-ft/yr 9 acre-ft/yr
Water exported: 7 447.552 acre-ft/yr 9 acre-ft/yr
Enter negative % or value for under-registration
WATER SUPPLIED: 32,338.845 acre-ft/yr Enter positive % or value for over-registration .

AUTHORIZED CONSUMPTION
Billed metered: 7 30,582.450 acre-ft/yr
Billed unmetered: n/a acre-ft/yr
Unbilled metered: 8 63.340 acre-ft/yr Pcnt: Value:

Unbilled unmetered: 404.236 acre-ft/yr 1.25% 24061 acre-ft/yr Default option selected for Unbilled unmetered - a grading of 5 is applied but not displayed AUTHORIZED CONSUMPTION: 31,050.026 acre-ft/yr
WATER LOSSES (Water Supplied - Authorized Consumption) 1,288.819 acre-ft/yr Apparent Losses Pcnt: Value:

Unauthorized consumption: 80.847 acre-ft/yr 0.25% acre-ft/yr Default option selected for unauthorized consumption - a grading of 5 is applied but not displayed Customer metering inaccuracies: 5 625.424 acre-ft/yr 2.00% acre-ft/yr Systematic data handling errors: 76.456 acre-ft/yr 0.25% acre-ft/yr Default option selected for Systematic data handling errors - a grading of 5 is applied but not displayed Apparent Losses: 782.728 acre-ft/yr
Real Losses (Current Annual Real Losses or CARL)
Real Losses = Water Losses - Apparent Losses: 506.092 acre-ft/yr WATER LOSSES: 1,288.819 acre-ft/yr

NON-REVENUE WATER
NON-REVENUE WATER: 1,756.395 acre-ft/yr
= Water Losses + Unbilled Metered + Unbilled Unmetered

SYSTEM DATA
Length of mains: 7 851.0 miles
Number of active AND inactive service connections: 7 45,092 Service connection density: 53 conn./mile main
Are customer meters typically located at the curbstop or property line? Yes Average length of customer service line: ft
Average length of customer service line has been set to zero and a data grading score of 10 has been applied Average operating pressure: 7 93.3 psi

COST DATA
Total annual cost of operating water system: 10 $48,508,297 $/Year Customer retail unit cost (applied to Apparent Losses): 10 $2.38 $/100 cubic feet (ccf) Variable production cost (applied to Real Losses): 5 $689.17 $/acre-ft WATER AUDIT DATA VALIDITY SCORE:
*** YOUR SCORE IS: 70 out of 100 ***
A weighted scale for the components of consumption and water loss is included in the calculation of the Water Audit Data Validity Score PRIORITY AREAS FOR ATTENTION:

Based on the information provided, audit accuracy can be improved by addressing the following components:
1: Volume from own sources
2: Customer metering inaccuracies
3: Variable production cost (applied to Real Losses)
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? Click to access definition
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Please enter data in the white cells below. Where available, metered values should be used; if metered values are unavailable please estimate a value. Indicate your confidence in the accuracy of the input data by grading each component (n/a or 1-10) using the drop-down list to the left of the input cell. Hover the mouse over the cell to obtain a description of the grades ?
?
?
?
?
?
(length of service line, beyond the property
boundary, that is the responsibility of the utility)
Use buttons to select
percentage of water
supplied
OR
value
Click here: ?
for help using option
buttons below
?
?
?
?
+
+ Click to add a comment
WAS v5.0
+
+
+
+
+
+
American Water Works Association.

Copyright © 2014, All Rights Reserved.
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+
+
+
+
+
+
+
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+
+
+
+
+ Use Customer Retail Unit Cost to value real losses
?
To select the correct data grading for each input, determine the highest grade where the utility meets or exceeds all criteria for that grade and all grades below it.

AWWA Free Water Audit Software v5.0 Reporting Worksheet 1

Page 1676 of 3356 ends

AWWA Free Water Audit Software:

System Attributes and Performance Indicators
Water Audit Report for: City of Corona (CA3310037)
Reporting Year: 20/21 7/2020 - 6/2021
*** YOUR WATER AUDIT DATA VALIDITY SCORE IS: 70 out of 100 *** System Attributes:

Apparent Losses: 782.728 acre-ft/yr
+ Real Losses: 506.092 acre-ft/yr
= Water Losses: 1,288.819 acre-ft/yr
Unavoidable Annual Real Losses (UARL): 1,188.01 acre-ft/yr Annual cost of Apparent Losses: $811,476
Annual cost of Real Losses: $348,783 Valued at Variable Production Cost Return to Reporting Worksheet to change this assumpiton Performance Indicators:

Non-revenue water as percent by volume of Water Supplied: 5.4% Non-revenue water as percent by cost of operating system: 3.1% Real Losses valued at Variable Production Cost Apparent Losses per service connection per day: 15.50 gallons/connection/day Real Losses per service connection per day: 10.02 gallons/connection/day Real Losses per length of main per day*: N/A
Real Losses per service connection per day per psi pressure: 0.11 gallons/connection/day/psi From Above, Real Losses = Current Annual Real Losses (CARL): 506.09 acre-feet/year Infrastructure Leakage Index (ILI) [CARL/UARL]: 0.43
* This performance indicator applies for systems with a low service connection density of less than 32 service connections/mile of pipeline ?
?
American Water Works Association.

WAS v5.0
Financial:

Operational Efficiency:

AWWA Free Water Audit Software v5.0 Performance Indicators 1

Page 1677 of 3356 ends

General Comment:

Audit Item Comment
Volume from own sources:

Well 3 + Well 20 + Well 21 + Temescal Desalter Effluent + Lester Production + SDO Production. All raw sources. Magnetic meters are monitored daily in WIMS and SCADA. Physical meter verification is conducted daily on about half of all production meters. Comments: Input derivation from supporting documents confirmed.

Exclusion of non-potable volumes confirmed. Corona DWP will be installing a new Mag meter at the Lester Plant effluent soon.

Vol. from own sources: Master meter
error adjustment: Electronic Calibration performed in FY 20/21 to Production Mag Meters.

Water imported: (Treated) Mills WR-24 and Arlington Desalter. Magnetic meters are monitored daily in WIMS and SCADA.

Water imported: master meter error
adjustment: Electronic Calibration performed in FY 20/21 to WI Mag Meters. Adjustments made as needed at time of annual calibration.

Water exported: Norco Connection and Home Gardens. Magnetic meters are monitored daily in WIMS and SCADA.

Water exported: master meter error
adjustment: Electronic Calibration performed in FY 20/21 to WE Mag Meters. Adjustments made as needed at time of annual calibration.

Billed metered: Provided by Customer Care's CIS Infinity V3 software. Meters are read manually monthly. Small portion of system is AMR (read monthly).

Billed unmetered:

Unbilled metered:
*Monthly Dead-end Hydrants =1,115,119 gallons. Quarterly Dead-end Hydrants = 23,711 gallons. Annual Dead-end Hydrants = 207,111 gallons. Total Flushing =

4.13 AF. Hydrant Monitoring for Water Quality = 7.61 AF. *22,7480 units to the Stein Account under contract. It equals 51.6 AF for the fiscal year.

Unbilled unmetered:

Unauthorized consumption:

Customer metering inaccuracies:

Systematic data handling errors:

Length of mains: See support file.

Number of active AND inactive
service connections:

Value provided by Customer Care for Drinking Water Annual Report. Total Active Connections + Total Other Connections (fire suppression, street cleaning, construction meters, temporary meters, line flushing) = 45,092 Average length of customer service
line:

Average operating pressure: Engineering provided pressures from 6 distinct pressure zones. Pressure is monitored on critical infrastructure and PRVs throughout the system and recorded on SCADA, calculated average pressure range at all zones.

Total annual cost of operating water
system: Calculation provided by our Busines Unit division.

Customer retail unit cost (applied to
Apparent Losses): Calculation based on dividing total revenue by the total volume of billed consumption.

AWWA Free Water Audit Software:

User Comments
Use this worksheet to add comments or notes to explain how an input value was calculated, or to document the sources of the information used. WAS v5.0 American Water Works Association. Copyright © 2014, All Rights Reserved.

AWWA Free Water Audit Software v5.0 Comments 1 Page 1678 of 3356 Audit Item Comment
Variable production cost (applied to
Real Losses): Calculation provided by our Business Unit division.

AWWA Free Water Audit Software v5.0 Comments 2 Page 1679 of 3356 AWWA Free Water Audit Software: Water Balance
Water Audit Report for: City of Corona (CA3310037)
Reporting Year: 20/21 7/2020 - 6/2021
Data Validity Score: 70
Water Exported
Billed Water Exported
Revenue Water
447.552 447.552
Billed Authorized Consumption
Billed Metered Consumption (water exported
is removed)
Revenue Water
30,582.450
Own Sources Authorized
Consumption 30,582.450 Billed Unmetered Consumption 30,582.450 (Adjusted for known
errors)

0.000
31,050.026 Unbilled Authorized Consumption
Unbilled Metered Consumption Non-Revenue Water
(NRW) 63.340
31,465.843 467.576 Unbilled Unmetered Consumption
404.236
System Input Water Supplied Unauthorized Consumption 1,756.395 32,786.397 Apparent Losses 80.847
32,338.845 782.728 Customer Metering Inaccuracies
625.424
Systematic Data Handling Errors
Water Losses 76.456
Water Imported 1,288.819 Leakage on Transmission and/or Distribution Mains
Real Losses Not broken down
1,320.554 506.092 Leakage and Overflows at Utility's Storage Tanks
Not broken down
Leakage on Service Connections
Not broken down
WAS v5.0
American Water Works Association.

AWWA Free Water Audit Software v5.0 Water Balance 1

Page 1680 of 3356 ends

Water Audit Report for:

Reporting Year: 20/21 Show me the VOLUME of Non-Revenue Water Data Validity Score: 70 Show me the COST of Non-Revenue Water AWWA Free Water Audit Software:

Dashboard
7/2020 - 6/2021
City of Corona (CA3310037)
0 100,000
200,000
300,000
400,000
500,000
600,000
700,000 Cost $
Total Cost of NRW =$1,482,498
Unbilled metered (valued at Var. Prod. Cost) Unbilled unmetered (valued at Var. Prod. Cost) Unauth. consumption Cust. metering inaccuracies Syst. data handling errors Real Losses (valued at Var. Prod. Cost) WAS v5.0
American Water Works Association.

Water Exported Authorized Consumption Water Losses 0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Water Exported Water Imported Volume From Own Sources Real Losses Apparent Losses Unbilled Auth. Cons. Billed Auth. Cons. Water Exported Non Revenue Water Revenue Water Water Exported The graphic below is a visual representation of the
Water Balance with bar heights propotional to the
volume of the audit components
Water Exported Water Supplied
AWWA Free Water Audit Software v5.0 Dashboard 1 Page 1681 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Volume from own sources:

Select this grading only if
the water utility
purchases/imports all of
its water resources (i.e.
has no sources of its own)
Less than 25% of water production
sources are metered, remaining
sources are estimated. No regular
meter accuracy testing or electronic
calibration conducted.
25% - 50% of treated water
production sources are metered;
other sources estimated. No regular
meter accuracy testing or electronic
calibration conducted.

Conditions between
2 and 4
50% - 75% of treated water
production sources are metered,
other sources estimated. Occasional
meter accuracy testing or electronic
calibration conducted.

Conditions between
4 and 6
At least 75% of treated water
production sources are metered, or at
least 90% of the source flow is derived
from metered sources. Meter
accuracy testing and/or electronic
calibration of related instrumentation is
conducted annually. Less than 25% of
tested meters are found outside of +/-
6% accuracy.

Conditions between
6 and 8
100% of treated water production
sources are metered, meter accuracy
testing and electronic calibration of
related instrumentation is conducted
annually, less than 10% of meters are
found outside of +/- 6% accuracy
Conditions between
8 and 10
100% of treated water production
sources are metered, meter accuracy
testing and electronic calibration of
related instrumentation is conducted
semi-annually, with less than 10%
found outside of +/- 3% accuracy.

Procedures are reviewed by a third
party knowledgeable in the M36
methodology.

Improvements to attain higher
data grading for "Volume from
own Sources" component:
to qualify for 2:

Organize and launch efforts to
collect data for determining volume
from own sources
to maintain 10:

Standardize meter accuracy test
frequency to semi-annual, or more
frequent, for all meters. Repair or
replace meters outside of +/- 3%
accuracy. Continually investigate/pilot
improving metering technology.

Volume from own sources
master meter and supply error
adjustment:

Select n/a only if the water
utility fails to have meters
on its sources of supply
Inventory information on meters and
paper records of measured volumes
exist but are incomplete and/or in a
very crude condition; data error
cannot be determined
No automatic datalogging of
production volumes; daily readings
are scribed on paper records without
any accountability controls. Flows
are not balanced across the water
distribution system: tank/storage
elevation changes are not employed
in calculating the "Volume from own
sources" component and archived
flow data is adjusted only when
grossly evident data error occurs.

Conditions between
2 and 4
Production meter data is logged
automatically in electronic format
and reviewed at least on a monthly
basis with necessary corrections
implemented. "Volume from own
sources" tabulations include
estimate of daily changes in
tanks/storage facilities. Meter data is
adjusted when gross data errors
occur, or occasional meter testing
deems this necessary.

Conditions between
4 and 6
Hourly production meter data logged
automatically & reviewed on at least a
weekly basis. Data is adjusted to
correct gross error when
meter/instrumentation equipment
malfunction is detected; and/or error is
confirmed by meter accuracy testing.

Tank/storage facility elevation
changes are automatically used in
calculating a balanced "Volume from
own sources" component, and data
gaps in the archived data are
corrected on at least a weekly basis.

Conditions between
6 and 8
Continuous production meter data is
logged automatically & reviewed each
business day. Data is adjusted to
correct gross error from detected
meter/instrumentation equipment
malfunction and/or results of meter
accuracy testing. Tank/storage facility
elevation changes are automatically
used in "Volume from own sources"
tabulations and data gaps in the
archived data are corrected on a daily
basis.

Conditions between
8 and 10
Computerized system (SCADA or
similar) automatically balances flows
from all sources and storages; results
are reviewed each business day. Tight
accountability controls ensure that all
data gaps that occur in the archived
flow data are quickly detected and
corrected. Regular calibrations between
SCADA and sources meters ensures
minimal data transfer error.

Improvements to attain higher
data grading for "Master meter
and supply error adjustment"
component:
to qualify for 2:

Develop a plan to restructure
recordkeeping system to capture all
flow data; set a procedure to review
flow data on a daily basis to detect
input errors. Obtain more reliable
information about existing meters by
conducting field inspections of
meters and related instrumentation,
and obtaining manufacturer
literature.
to maintain 10:

Monitor meter innovations for
development of more accurate and less
expensive flowmeters. Continue to
replace or repair meters as they
perform outside of desired accuracy
limits. Stay abreast of new and more
accurate water level instruments to
better record tank/storage levels and
archive the variations in storage
volume. Keep current with SCADA and
data management systems to ensure
that archived data is well-managed and
error free.

Water Imported:

Select n/a if the water
utility's supply is
exclusively from its own
water resources (no bulk
purchased/ imported
water)
Less than 25% of imported water
sources are metered, remaining
sources are estimated. No regular
meter accuracy testing.
25% - 50% of imported water
sources are metered; other sources
estimated. No regular meter
accuracy testing.

Conditions between
2 and 4
50% - 75% of imported water
sources are metered, other sources
estimated. Occasional meter
accuracy testing conducted.

Conditions between
4 and 6
At least 75% of imported water
sources are metered, meter accuracy
testing and/or electronic calibration of
related instrumentation is conducted
annually for all meter installations.

Less than 25% of tested meters are
found outside of +/- 6% accuracy.

Conditions between
6 and 8
100% of imported water sources are
metered, meter accuracy testing and
electronic calibration of related
instrumentation is conducted
annually, less than 10% of meters are
found outside of +/- 6% accuracy
Conditions between
8 and 10
100% of imported water sources are
metered, meter accuracy testing and
electronic calibration of related
instrumentation is conducted semiannually for all meter installations, with less than 10% of accuracy tests found
outside of +/- 3% accuracy.
to qualify for 4:

Locate all water production sources on maps and in the
field, launch meter accuracy testing for existing meters, begin to install meters on unmetered water production
sources and replace any obsolete/defective meters.

AWWA Free Water Audit Software: Grading Matrix
The grading assigned to each audit component and the corresponding recommended improvements and actions are highlighted in yellow. Audit accuracy is likely to be improved by prioritizing those items shown in red to qualify for 6:

Refine computerized data collection and archive to include hourly production meter data that is reviewed at least on a weekly basis to detect specific data anomalies and gaps.

Use daily net storage change to balance flows in calculating "Water Supplied" volume. Necessary corrections to data
errors are implemented on a weekly basis.
to qualify for 8:

Ensure that all flow data is collected and archived on at least an hourly basis. All data is reviewed and detected errors corrected each business day. Tank/storage levels variations are employed in calculating balanced "Water
Supplied" component. Adjust production meter data for
gross error and inaccuracy confirmed by testing.
to qualify for 10:

Link all production and tank/storage facility elevation change data to a Supervisory Control & Data Acquisition (SCADA) System, or similar computerized monitoring/control system, and establish automatic flow balancing algorithm and regularly calibrate between SCADA and source meters. Data is
reviewed and corrected each business day.
to qualify for 6:

Formalize annual meter accuracy testing for all source
meters; specify the frequency of testing. Complete
installation of meters on unmetered water production
sources and complete replacement of all obsolete/defective meters.
to qualify for 8:

Conduct annual meter accuracy testing and calibration of related instrumentation on all meter installations on a regular basis. Complete project to install new, or replace defective existing, meters so that entire production meter population is metered. Repair or replace meters outside of +/- 6% accuracy.
to qualify for 10:

Maintain annual meter accuracy testing and calibration of related instrumentation for all meter installations. Repair or replace meters outside of +/- 3% accuracy. Investigate new meter technology; pilot one or more replacements with
innovative meters in attempt to further improve meter
accuracy.
to qualify for 4:

Install automatic datalogging equipment on production
meters. Complete installation of level instrumentation at all tanks/storage facilities and include tank level data in automatic calculation routine in a computerized system.

Construct a computerized listing or spreadsheet to archive input volumes, tank/storage volume changes and
import/export flows in order to determine the composite "Water Supplied" volume for the distribution system. Set a procedure to review this data on a monthly basis to
detect gross anomalies and data gaps.

WATER SUPPLIED
WAS 5.0
American Water Works Association. Copyright © 2014, All Rights Reserved.

AWWA Free Water Audit Software v5.0 Grading Matrix 1 Page 1682 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Improvements to attain higher
data grading for "Water
Imported Volume" component:
(Note: usually the water
supplier selling the water - "the
Exporter" - to the utility being
audited is responsible to
maintain the metering
installation measuring the
imported volume. The utility
should coordinate carefully
with the Exporter to ensure
that adequate meter upkeep
takes place and an accurate
measure of the Water
Imported volume is quantified. )
to qualify for 2:

Review bulk water purchase
agreements with partner suppliers;
confirm requirements for use and
maintenance of accurate metering.

Identify needs for new or
replacement meters with goal to
meter all imported water sources.
to maintain 10:

Standardize meter accuracy test
frequency to semi-annual, or more
frequent, for all meters. Continue to
conduct calibration of related
instrumentation on a semi-annual
basis. Repair or replace meters
outside of +/- 3% accuracy. Continually
investigate/pilot improving metering
technology.

Water imported master meter
and supply error adjustment:

Select n/a if the Imported
water supply is
unmetered, with Imported
water quantities estimated
on the billing invoices sent
by the Exporter to the
purchasing Utility.

Inventory information on imported
meters and paper records of
measured volumes exist but are
incomplete and/or in a very crude
condition; data error cannot be
determined Written agreement(s)
with water Exporter(s) are missing
or written in vague language
concerning meter management and
testing.

No automatic datalogging of
imported supply volumes; daily
readings are scribed on paper
records without any accountability
controls to confirm data accuracy
and the absence of errors and data
gaps in recorded volumes. Written
agreement requires meter accuracy
testing but is vague on the details of
how and who conducts the testing.

Conditions between
2 and 4
Imported supply metered flow data is
logged automatically in electronic
format and reviewed at least on a
monthly basis by the Exporter with
necessary corrections implemented.

Meter data is adjusted by the
Exporter when gross data errors are
detected. A coherent data trail exists
for this process to protect both the
selling and the purchasing Utility.

Written agreement exists and clearly
states requirements and roles for
meter accuracy testing and data
management.

Conditions between
4 and 6
Hourly Imported supply metered data
is logged automatically & reviewed on
at least a weekly basis by the
Exporter. Data is adjusted to correct
gross error when
meter/instrumentation equipment
malfunction is detected; and to correct
for error confirmed by meter accuracy
testing. Any data gaps in the archived
data are detected and corrected
during the weekly review. A coherent
data trail exists for this process to
protect both the selling and the
purchasing Utility.

Conditions between
6 and 8
Continuous Imported supply metered
flow data is logged automatically &
reviewed each business day by the
Exporter. Data is adjusted to correct
gross error from detected
meter/instrumentation equipment
malfunction and/or results of meter
accuracy testing. Any data
errors/gaps are detected and
corrected on a daily basis. A data trail
exists for the process to protect both
the selling and the purchasing Utility.

Conditions between
8 and 10
Computerized system (SCADA or
similar) automatically records data
which is reviewed each business day by
the Exporter. Tight accountability
controls ensure that all error/data gaps
that occur in the archived flow data are
quickly detected and corrected. A
reliable data trail exists and contract
provisions for meter testing and data
management are reviewed by the
selling and purchasing Utility at least
once every five years.

Improvements to attain higher
data grading for "Water
imported master meter and
supply error adjustment"
component:
to qualify for 2:

Monitor meter innovations for
development of more accurate and less
expensive flowmeters; work with the
Exporter to help identify meter
replacement needs. Keep
communication lines with Exporters
open and maintain productive relations.

Keep the written agreement current
with clear and explicit language that
meets the ongoing needs of all parties.

Water Exported:

Select n/a if the water
utility sells no bulk water
to neighboring water
utilities (no exported water
sales)
Less than 25% of exported water
sources are metered, remaining
sources are estimated. No regular
meter accuracy testing.
25% - 50% of exported water
sources are metered; other sources
estimated. No regular meter
accuracy testing.

Conditions between
2 and 4
50% - 75% of exported water
sources are metered, other sources
estimated. Occasional meter
accuracy testing conducted.

Conditions between
4 and 6
At least 75% of exported water
sources are metered, meter accuracy
testing and/or electronic calibration
conducted annually. Less than 25% of
tested meters are found outside of +/-
6% accuracy.

Conditions between
6 and 8
100% of exported water sources are
metered, meter accuracy testing and
electronic calibration of related
instrumentation is conducted
annually, less than 10% of meters are
found outside of +/- 6% accuracy
Conditions between
8 and 10
100% of exported water sources are
metered, meter accuracy testing and
electronic calibration of related
instrumentation is conducted semiannually for all meter installations, with less than 10% of accuracy tests found
outside of +/- 3% accuracy.
to qualify for 8:

Complete project to install new, or replace defective, meters on all imported water interconnections. Maintain annual meter accuracy testing for all imported water meters and conduct calibration of related instrumentation at least annually. Repair or replace meters outside of +/- 6%
accuracy.
to qualify for 4:

Install automatic datalogging equipment on Imported
supply meters. Set a procedure to review this data on a monthly basis to detect gross anomalies and data gaps.

Launch discussions with the Exporters to jointly review terms of the written agreements regarding meter accuracy testing and data management; revise the terms as
necessary.
to qualify for 6:

Refine computerized data collection and archive to include hourly Imported supply metered flow data that is reviewed at least on a weekly basis to detect specific data anomalies and gaps. Make necessary corrections to errors/data errors on a weekly basis.
to qualify for 8:

Ensure that all Imported supply metered flow data is
collected and archived on at least an hourly basis. All data is reviewed and errors/data gaps are corrected each
business day.

To qualify for 4:

Locate all imported water sources on maps and in the
field, launch meter accuracy testing for existing meters, begin to install meters on unmetered imported water
interconnections and replace obsolete/defective meters. to qualify for 6:

Formalize annual meter accuracy testing for all imported water meters, planning for both regular meter accuracy
testing and calibration of the related instrumentation.

Continue installation of meters on unmetered imported
water interconnections and replacement of
obsolete/defective meters.
to qualify for 10:

Conduct meter accuracy testing for all meters on a semiannual basis, along with calibration of all related instrumentation. Repair or replace meters outside of +/- 3% accuracy. Investigate new meter technology; pilot one or more replacements with innovative meters in attempt to
improve meter accuracy.
to qualify for 10:

Conduct accountability checks to confirm that all Imported supply metered data is reviewed and corrected each business day by the Exporter. Results of all meter accuracy tests and data corrections should be available for sharing between the Exporter and the purchasing Utility. Establish a schedule for a regular review and updating of the contractual language in the written agreement between the selling and the purchasing Utility; at least every five years.

AWWA Free Water Audit Software v5.0 Grading Matrix 2 Page 1683 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Improvements to attain higher
data grading for "Water
Exported Volume" component:
(Note: usually, if the water
utility being audited sells
(Exports) water to a
neighboring purchasing Utility,
it is the responsibility of the
utility exporting the water to
maintain the metering
installation measuring the
Exported volume. The utility
exporting the water should
ensure that adequate meter
upkeep takes place and an
accurate measure of the
Water Exported volume is
quantified. )
to qualify for 2:

Review bulk water sales
agreements with purchasing
utilities; confirm requirements for
use & upkeep of accurate metering.

Identify needs to install new, or
replace defective meters as
needed.
to maintain 10:

Water exported master meter
and supply error adjustment:

Select n/a only if the water
utility fails to have meters
on its exported supply
interconnections.

Inventory information on exported
meters and paper records of
measured volumes exist but are
incomplete and/or in a very crude
condition; data error cannot be
determined Written agreement(s)
with the utility purchasing the water
are missing or written in vague
language concerning meter
management and testing.

No automatic datalogging of
exported supply volumes; daily
readings are scribed on paper
records without any accountability
controls to confirm data accuracy
and the absence of errors and data
gaps in recorded volumes. Written
agreement requires meter accuracy
testing but is vague on the details of
how and who conducts the testing.

Conditions between
2 and 4
Exported metered flow data is
logged automatically in electronic
format and reviewed at least on a
monthly basis, with necessary
corrections implemented. Meter
data is adjusted by the utility selling
(exporting) the water when gross
data errors are detected. A coherent
data trail exists for this process to
protect both the utility exporting the
water and the purchasing Utility.

Written agreement exists and clearly
states requirements and roles for
meter accuracy testing and data
management.

Conditions between
4 and 6
Hourly exported supply metered data
is logged automatically & reviewed on
at least a weekly basis by the utility
selling the water. Data is adjusted to
correct gross error when
meter/instrumentation equipment
malfunction is detected; and to correct
for error found by meter accuracy
testing. Any data gaps in the archived
data are detected and corrected
during the weekly review. A coherent
data trail exists for this process to
protect both the selling (exporting)
utility and the purchasing Utility.

Conditions between
6 and 8
Continuous exported supply metered
flow data is logged automatically &
reviewed each business day by the
utility selling (exporting) the water.

Data is adjusted to correct gross error
from detected meter/instrumentation
equipment malfunction and any error
confirmed by meter accuracy testing.

Any data errors/gaps are detected
and corrected on a daily basis. A data
trail exists for the process to protect
both the selling (exporting) Utility and
the purchasing Utility.

Conditions between
8 and 10
Computerized system (SCADA or
similar) automatically records data
which is reviewed each business day by
the utility selling (exporting) the water.

Tight accountability controls ensure that
all error/data gaps that occur in the
archived flow data are quickly detected
and corrected. A reliable data trail
exists and contract provisions for meter
testing and data management are
reviewed by the selling Utility and
purchasing Utility at least once every
five years.

Improvements to attain higher
data grading for "Water
exported master meter and
supply error adjustment"
component:
to qualify for 2:

Monitor meter innovations for
development of more accurate and less
expensive flowmeters; work with the
purchasing utilities to help identify
meter replacement needs. Keep
communication lines with the
purchasing utilities open and maintain
productive relations. Keep the written
agreement current with clear and
explicit language that meets the
ongoing needs of all parties.
to qualify for 6:

Formalize annual meter accuracy testing for all exported water meters. Continue installation of meters on unmetered exported water interconnections and replacement of
obsolete/defective meters.
to qualify for 8:

Complete project to install new, or replace defective, meters on all exported water interconnections. Maintain annual meter accuracy testing for all exported water meters.

Repair or replace meters outside of +/- 6% accuracy.
to qualify for 10:

Maintain annual meter accuracy testing for all meters. Repair or replace meters outside of +/- 3% accuracy. Investigate new meter technology; pilot one or more replacements with innovative meters in attempt to improve meter accuracy. to qualify for 4:

Install automatic datalogging equipment on exported
supply meters. Set a procedure to review this data on a monthly basis to detect gross anomalies and data gaps.

Launch discussions with the purchasing utilities to jointly review terms of the written agreements regarding meter
accuracy testing and data management; revise the terms
as necessary.

AUTHORIZED CONSUMPTION
to qualify for 10:

Conduct accountability checks to confirm that all exported metered flow data is reviewed and corrected each business day by the utility selling the water. Results of all meter accuracy tests and data corrections should be available for sharing between the utility and the purchasing Utility.

Establish a schedule for a regular review and updating of the contractual language in the written agreements with the purchasing utilities; at least every five years.

To qualify for 4:

Locate all exported water sources on maps and in field, launch meter accuracy testing for existing meters, begin to install meters on unmetered exported water
interconnections and replace obsolete/defective meters
to qualify for 6:

Refine computerized data collection and archive to include hourly exported supply metered flow data that is reviewed at least on a weekly basis to detect specific data anomalies and gaps. Make necessary corrections to errors/data errors on a weekly basis.
to qualify for 8:

Ensure that all exported metered flow data is collected and archived on at least an hourly basis. All data is reviewed and errors/data gaps are corrected each business day.

AWWA Free Water Audit Software v5.0 Grading Matrix 3 Page 1684 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Billed metered:
n/a (not applicable).

Select n/a only if the
entire customer
population is not metered
and is billed for water
service on a flat or fixed
rate basis. In such a case
the volume entered must
be zero.

Less than 50% of customers with
volume-based billings from meter
readings; flat or fixed rate billing
exists for the majority of the
customer population
At least 50% of customers with
volume-based billing from meter
reads; flat rate billing for others.

Manual meter reading is conducted,
with less than 50% meter read
success rate, remainding accounts'
consumption is estimated. Limited
meter records, no regular meter
testing or replacement. Billing data
maintained on paper records, with
no auditing.

Conditions between
2 and 4
At least 75% of customers with
volume-based, billing from meter
reads; flat or fixed rate billing for
remaining accounts. Manual meter
reading is conducted with at least
50% meter read success rate;
consumption for accounts with failed
reads is estimated. Purchase
records verify age of customer
meters; only very limited meter
accuracy testing is conducted.

Customer meters are replaced only
upon complete failure.

Computerized billing records exist,
but only sporadic internal auditing
conducted.

Conditions between
4 and 6
At least 90% of customers with
volume-based billing from meter
reads; consumption for remaining
accounts is estimated. Manual
customer meter reading gives at least
80% customer meter reading success
rate; consumption for accounts with
failed reads is estimated. Good
customer meter records eixst, but only
limited meter accuracy testing is
conducted. Regular replacement is
conducted for the oldest meters.

Computerized billing records exist with
annual auditing of summary statistics
conducting by utility personnel.

Conditions between
6 and 8
At least 97% of customers exist with
volume-based billing from meter
reads. At least 90% customer meter
reading success rate; or at least 80%
read success rate with planning and
budgeting for trials of Automatic Meter
Reading (AMR) or Advanced Metering
Infrastructure (AMI) in one or more
pilot areas. Good customer meter
records. Regular meter accuracy
testing guides replacement of
statistically significant number of
meters each year. Routine auditing of
computerized billing records for global
and detailed statistics occurs annually
by utility personnel, and is verified by
third party at least once every five
years.

Conditions between
8 and 10
At least 99% of customers exist with
volume-based billing from meter reads.

At least 95% customer meter reading
success rate; or minimum 80% meter
reading success rate, with Automatic
Meter Reading (AMR) or Advanced
Metering Infrastructure (AMI) trials
underway. Statistically significant
customer meter testing and
replacement program in place on a
continuous basis. Computerized billing
with routine, detailed auditing, including
field investigation of representative
sample of accounts undertaken
annually by utility personnel. Audit is
conducted by third party auditors at
least once every three years.

Improvements to attain higher
data grading for "Billed
Metered Consumption"
component:

If n/a is selected because
the customer meter
population is unmetered,
consider establishing a
new policy to meter the
customer population and
employ water rates based
upon metered volumes.
to qualify for 2:

Conduct investigations or trials of
customer meters to select
appropriate meter models. Budget
funding for meter installations.

Investigate volume based water rate
structures.
to maintain 10:

Continue annual internal billing data
auditing, and third party auditing at
least every three years. Continue
customer meter accuracy testing to
ensure that accurate customer meter
readings are obtained and entered as
the basis for volume based billing. Stay
abreast of improvements in Automatic
Meter Reading (AMR) and Advanced
Metering Infrastructure (AMI) and
information management. Plan and
budget for justified upgrades in
metering, meter reading and billing data
management to maintain very high
accuracy in customer metering and
billing.

Billed unmetered:

Select n/a if it is the policy
of the water utility to meter
all customer connections
and it has been confirmed
by detailed auditing that
all customers do indeed
have a water meter; i.e.
no intentionally unmetered
accounts exist
Water utility policy does not require
customer metering; flat or fixed fee
billing is employed. No data is
collected on customer consumption.

The only estimates of customer
population consumption available
are derived from data estimation
methods using average fixture
count multiplied by number of
connections, or similar approach.

Water utility policy does not require
customer metering; flat or fixed fee
billing is employed. Some metered
accounts exist in parts of the system
(pilot areas or District Metered
Areas) with consumption read
periodically or recorded on portable
dataloggers over one, three, or
seven day periods. Data from these
sample meters are used to infer
consumption for the total customer
population. Site specific estimation
methods are used for unusual
buildings/water uses.

Conditions between
2 and 4
Water utility policy does require
metering and volume based billing in
general. However, a liberal amount
of exemptions and a lack of clearly
written and communicated
procedures result in up to 20% of
billed accounts believed to be
unmetered by exemption; or the
water utility is in transition to
becoming fully metered, and a large
number of customers remain
unmetered. A rough estimate of the
annual consumption for all
unmetered accounts is included in
the annual water audit, with no
inspection of individual unmetered
accounts.

Conditions between
4 and 6
Water utility policy does require
metering and volume based billing but
established exemptions exist for a
portion of accounts such as municipal
buildings. As many as 15% of billed
accounts are unmetered due to this
exemption or meter installation
difficulties. Only a group estimate of
annual consumption for all unmetered
accounts is included in the annual
water audit, with no inspection of
individual unmetered accounts.

Conditions between
6 and 8
Water utility policy does require
metering and volume based billing for
all customer accounts. However, less
than 5% of billed accounts remain
unmetered because meter installation
is hindered by unusual circumstances.

The goal is to minimize the number of
unmetered accounts. Reliable
estimates of consumption are
obtained for these unmetered
accounts via site specific estimation
methods.

Conditions between
8 and 10
Water utility policy does require
metering and volume based billing for
all customer accounts. Less than 2%
of billed accounts are unmetered and
exist because meter installation is
hindered by unusual circumstances.

The goal exists to minimize the number
of unmetered accounts to the extent
that is economical. Reliable estimates
of consumption are obtained at these
accounts via site specific estimation
methods.
to qualify for 8:

Purchase and install meters on unmetered accounts. If
customer meter reading success rate is less than 97%,
assess cost-effectiveness of Automatic Meter Reading
(AMR) or Advanced Metering Infrastructure (AMI) system
for portion or entire system; or otherwise achieve ongoing improvements in manual meter reading success rate to
97% or higher. Refine meter accuracy testing program.

Set meter replacement goals based upon accuracy test
results. Implement annual auditing of detailed billing
records by utility personnel and implement third party
auditing at least once every five years.
to qualify for 4:

Purchase and install meters on unmetered accounts.

Implement policies to improve meter reading success.

Catalog meter information during meter read visits to
identify age/model of existing meters. Test a minimal
number of meters for accuracy. Install computerized
billing system.
to qualify for 6:

Purchase and install meters on unmetered accounts.

Eliminate flat fee billing and establish appropriate water rate structure based upon measured consumption. Continue to
achieve verifiable success in removing manual meter
reading barriers. Expand meter accuracy testing. Launch regular meter replacement program. Launch a program of
annual auditing of global billing statistics by utility personnel. to qualify for 10:

Purchase and install meters on unmetered accounts. Launch Automatic Meter Reading (AMR) or Advanced Metering
Infrastructure (AMI) system trials if manual meter reading success rate of at least 99% is not achieved within a five-year program. Continue meter accuracy testing program. Conduct planning and budgeting for large scale meter replacement based upon meter life cycle analysis using cumulative flow target. Continue annual detailed billing data auditing by utility personnel and conduct third party auditing at least once every three years.

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Improvements to attain higher
data grading for "Billed
Unmetered Consumption"
component:
to qualify for 2:

Conduct research and evaluate
cost/benefit of a new water utility
policy to require metering of the
customer population; thereby
greatly reducing or eliminating
unmetered accounts. Conduct pilot
metering project by installing water
meters in small sample of customer
accounts and periodically reading
the meters or datalogging the water
consumption over one, three, or
seven day periods.
to maintain 10:

Continue to refine estimation methods
for unmetered consumption and explore
means to establish metering, for as
many billed remaining unmetered
accounts as is economically feasible.

Unbilled metered:
select n/a if all billingexempt consumption is
unmetered.

Billing practices exempt certain
accounts, such as municipal
buildings, but written policies do not
exist; and a reliable count of
unbilled metered accounts is
unavailable. Meter upkeep and
meter reading on these accounts is
rare and not considered a priority.

Due to poor recordkeeping and lack
of auditing, water consumption for
all such accounts is purely
guesstimated.

Billing practices exempt certain
accounts, such as municipal
buildings, but only scattered, dated
written directives exist to justify this
practice. A reliable count of unbilled
metered accounts is unavailable.

Sporadic meter replacement and
meter reading occurs on an asneeded basis. The total annual water consumption for all unbilled,
metered accounts is estimated
based upon approximating the
number of accounts and assigning
consumption from actively billed
accounts of same meter size.

Conditions between
2 and 4
Dated written procedures permit
billing exemption for specific
accounts, such as municipal
properties, but are unclear regarding
certain other types of accounts.

Meter reading is given low priority
and is sporadic. Consumption is
quantified from meter readings
where available. The total number of
unbilled, unmetered accounts must
be estimated along with consumption
volumes.

Conditions between
4 and 6
Written policies regarding billing
exemptions exist but adherence in
practice is questionable. Metering and
meter reading for municipal buildings
is reliable but sporadic for other
unbilled metered accounts. Periodic
auditing of such accounts is
conducted. Water consumption is
quantified directly from meter readings
where available, but the majority of the
consumption is estimated.

Conditions between
6 and 8
Written policy identifies the types of
accounts granted a billing exemption.

Customer meter management and
meter reading are considered
secondary priorities, but meter
reading is conducted at least annually
to obtain consumption volumes for the
annual water audit. High level
auditing of billing records ensures that
a reliable census of such accounts
exists.

Conditions between
8 and 10
Clearly written policy identifies the types
of accounts given a billing exemption,
with emphasis on keeping such
accounts to a minimum. Customer
meter management and meter reading
for these accounts is given proper
priority and is reliably conducted.

Regular auditing confirms this. Total
water consumption for these accounts
is taken from reliable readings from
accurate meters.

Improvements to attain higher
data grading for "Unbilled
Metered Consumption"
component:
to qualify for 2:

Reassess the water utility's policy
allowing certain accounts to be
granted a billing exemption. Draft
an outline of a new written policy for
billing exemptions, with clear
justification as to why any accounts
should be exempt from billing, and
with the intention to keep the
number of such accounts to a
minimum.
to maintain 10:

Reassess the utility's philosophy in
allowing any water uses to go
"unbilled". It is possible to meter and
bill all accounts, even if the fee charged
for water consumption is discounted or
waived. Metering and billing all
accounts ensures that water
consumption is tracked and water
waste from plumbing leaks is detected
and minimized.

Unbilled unmetered:

Extent of unbilled, unmetered
consumption is unknown due to
unclear policies and poor
recordkeeping. Total consumption
is quantified based upon a purely
subjective estimate.

Clear extent of unbilled, unmetered
consumption is unknown, but a
number of events are randomly
documented each year, confirming
existence of such consumption, but
without sufficient documentation to
quantify an accurate estimate of the
annual volume consumed.

Conditions between
2 and 4
Extent of unbilled, unmetered
consumption is partially known, and
procedures exist to document certain
events such as miscellaneous fire
hydrant uses. Formulae is used to
quantify the consumption from such
events (time running multiplied by
typical flowrate, multiplied by number
of events).

Default value of

1.25% of system input
volume is employed
Coherent policies exist for some forms
of unbilled, unmetered consumption
but others await closer evaluation.

Reasonable recordkeeping for the
managed uses exists and allows for
annual volumes to be quantified by
inference, but unsupervised uses are
guesstimated.

Conditions between
6 and 8
Clear policies and good
recordkeeping exist for some uses
(ex: water used in periodic testing of
unmetered fire connections), but other
uses (ex: miscellaneous uses of fire
hydrants) have limited oversight.

Total consumption is a mix of well
quantified use such as from formulae
(time running multiplied by typical
flow, multiplied by number of events)
or temporary meters, and relatively
subjective estimates of less regulated
use.

Conditions between
8 and 10
Clear policies exist to identify permitted
use of water in unbilled, unmetered
fashion, with the intention of minimizing
this type of consumption. Good records
document each occurrence and
consumption is quantified via formulae
(time running multiplied by typical flow,
multiplied by number of events) or use
of temporary meters.
to qualify for 8:

Push to install customer meters on a full scale basis.

Refine metering policy and procedures to ensure that all accounts, including municipal properties, are designated for meters. Plan special efforts to address "hard-to-access" accounts. Implement procedures to obtain a reliable
consumption estimate for the remaining few unmetered
accounts awaiting meter installation.
to qualify for 10:

Continue customer meter installation throughout the service area, with a goal to minimize unmetered accounts. Sustain the effort to investigate accounts with access difficulties, and devise means to install water meters or otherwise measure water consumption.
to qualify for 8:

Communicate billing exemption policy throughout the
organization and implement procedures that ensure proper account management. Conduct inspections of accounts
confirmed in unbilled metered status and verify that
accurate meters exist and are scheduled for routine meter readings. Gradually increase the number of unbilled
metered accounts that are included in regular meter reading routes.
to qualify for 4:

Review historic written directives and policy documents allowing certain accounts to be billing-exempt. Draft an outline of a written policy for billing exemptions, identify criteria that grants an exemption, with a goal of keeping this number of accounts to a minimum. Consider
increasing the priority of reading meters on unbilled
accounts at least annually.
to qualify for 6:

Draft a new written policy regarding billing exemptions based upon consensus criteria allowing this occurrence.

Assign resources to audit meter records and billing records to obtain census of unbilled metered accounts. Gradually include a greater number of these metered accounts to the routes for regular meter reading.
to qualify for 10:

Ensure that meter management (meter accuracy testing,
meter replacement) and meter reading activities for unbilled accounts are accorded the same priority as billed accounts.

Establish ongoing annual auditing process to ensure that water consumption is reliably collected and provided to the annual water audit process.
to qualify for 4:

Implement a new water utility policy requiring customer metering. Launch or expand pilot metering study to
include several different meter types, which will provide data for economic assessment of full scale metering
options. Assess sites with access difficulties to devise means to obtain water consumption volumes. Begin
customer meter installation.
to qualify for 6:

Refine policy and procedures to improve customer metering participation for all but solidly exempt accounts. Assign staff resources to review billing records to identify errant
unmetered properties. Specify metering needs and funding requirements to install sufficient meters to significant reduce the number of unmetered accounts
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Improvements to attain higher
data grading for "Unbilled
Unmetered Consumption"
component:
to qualify for 5:

Utilize the accepted default value of

1.25% of the volume of water
supplied as an expedient means to
gain a reasonable quantification of
this use.
to qualify for 2:

Establish a policy regarding what
water uses should be allowed to
remain as unbilled and unmetered.

Consider tracking a small sample of
one such use (ex: fire hydrant
flushings).
to qualify for 5:

Utilize accepted default value of

1.25% of the volume of water
supplied as an expedient means to
gain a reasonable quantification of
all such use. This is particularly
appropriate for water utilities who are
in the early stages of the water
auditing process, and should focus
on other components since the
volume of unbilled, umetered
consumption is usually a relatively
small quatity component, and other
larger-quantity components should
take priority.
to qualify for 6 or
greater:

Finalize policy and
begin to conduct field
checks to better
establish and quantify
such usage. Proceed
if top-down audit
exists and/or a great
volume of such use is
suspected.
to maintain 10:

Continue to refine policy and
procedures with intention of reducing
the number of allowable uses of water
in unbilled and unmetered fashion. Any
uses that can feasibly become billed
and metered should be converted
eventually.

Unauthorized consumption:

Extent of unauthorized consumption
is unknown due to unclear policies
and poor recordkeeping. Total
unauthorized consumption is
guesstimated.

Unauthorized consumption is a
known occurrence, but its extent is a
mystery. There are no requirements
to document observed events, but
periodic field reports capture some
of these occurrences. Total
unauthorized consumption is
approximated from this limited data.
conditions between
2 and 4
Procedures exist to document some
unauthorized consumption such as
observed unauthorized fire hydrant
openings. Use formulae to quantify
this consumption (time running
multiplied typical flowrate, multiplied
by number of events).

Default value of

0.25% of volume of
water supplied is
employed
Coherent policies exist for some forms
of unauthorized consumption (more
than simply fire hydrant misuse) but
others await closer evaluation.

Reasonable surveillance and
recordkeeping exist for occurrences
that fall under the policy. Volumes
quantified by inference from these
records.

Conditions between
6 and 8
Clear policies and good auditable
recordkeeping exist for certain events
(ex: tampering with water meters,
illegal bypasses of customer meters);
but other occurrences have limited
oversight. Total consumption is a
combination of volumes from
formulae (time x typical flow) and
subjective estimates of unconfirmed
consumption.

Conditions between
8 and 10
Clear policies exist to identify all known
unauthorized uses of water. Staff and
procedures exist to provide
enforcement of policies and detect
violations. Each occurrence is
recorded and quantified via formulae
(estimated time running multiplied by
typical flow) or similar methods. All
records and calculations should exist in
a form that can be audited by a third
party.

Improvements to attain higher
data grading for "Unauthorized
Consumption" component:
to qualify for 5:

Use accepted default of 0.25% of
volume of water supplied.
to qualify for 2:

Review utility policy regarding what
water uses are considered
unauthorized, and consider tracking
a small sample of one such
occurrence (ex: unauthorized fire
hydrant openings)
to qualify for 5:

Utilize accepted default value of

0.25% of volume of water supplied
as an expedient means to gain a
reasonable quantification of all such
use. This is particularly appropriate
for water utilities who are in the early
stages of the water auditing process.
to qualify for 6 or
greater:

Finalize policy
updates to clearly
identify the types of
water consumption
that are authorized
from those usages
that fall outside of this
policy and are,
therefore,
unauthorized. Begin
to conduct regular
field checks. Proceed
if the top-down audit
already exists and/or
a great volume of
such use is
suspected.
to maintain 10:

Continue to refine policy and
procedures to eliminate any loopholes
that allow or tacitly encourage
unauthorized consumption. Continue to
be vigilant in detection, documentation
and enforcement efforts.
to quality for 8:

Assess water utility policies to ensure that all known
occurrences of unauthorized consumption are outlawed,
and that appropriate penalties are prescribed. Create
written procedures for detection and documentation of
various occurrences of unauthorized consumption as they are uncovered.
to qualify for 10:

Refine written procedures and assign staff to seek out likely occurrences of unauthorized consumption. Explore new
locking devices, monitors and other technologies designed to detect and thwart unauthorized consumption.
to qualify for 8:

Assess water utility policy and procedures for various
unmetered usages. For example, ensure that a policy
exists and permits are issued for use of fire hydrants by persons outside of the utility. Create written procedures for use and documentation of fire hydrants by water utility personnel. Use same approach for other types of unbilled, unmetered water usage.
to qualify for 5:

Utilize accepted default value of 1.25% of the volume of water supplied as an expedient means to gain a
reasonable quantification of this use.
to qualify for 4:

Evaluate the documentation of events that have been
observed. Meet with user groups (ex: for fire hydrants - fire departments, contractors to ascertain their need
and/or volume requirements for water from fire hydrants).

APPARENT LOSSES
to qualify for 5:

Use accepted default of 0.25% of system input volume
to qualify for 4:

Review utility policy regarding what water uses are
considered unauthorized, and consider tracking a small
sample of one such occurrence (ex: unauthorized fire
hydrant openings)
to qualify for 10:

Refine written procedures to ensure that all uses of unbilled, unmetered water are overseen by a structured permitting process managed by water utility personnel. Reassess policy to determine if some of these uses have value in being
converted to billed and/or metered status.

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Customer metering
inaccuracies:
select n/a only if the entire
customer population is
unmetered. In such a
case the volume entered
must be zero.

Customer meters exist, but with
unorganized paper records on
meters; no meter accuracy testing
or meter replacement program for
any size of retail meter. Metering
workflow is driven chaotically with
no proactive management. Loss
volume due to aggregate meter
inaccuracy is guesstimated.

Poor recordkeeping and meter
oversight is recognized by water
utility management who has allotted
staff and funding resources to
organize improved recordkeeping
and start meter accuracy testing.

Existing paper records gathered and
organized to provide cursory
disposition of meter population.

Customer meters are tested for
accuracy only upon customer
request.

Conditions between
2 and 4
Reliable recordkeeping exists; meter
information is improving as meters
are replaced. Meter accuracy
testing is conducted annually for a
small number of meters (more than
just customer requests, but less than
1% of inventory). A limited number
of the oldest meters are replaced
each year. Inaccuracy volume is
largely an estimate, but refined
based upon limited testing data.

Conditions between
4 and 6
A reliable electronic recordkeeping
system for meters exists. The meter
population includes a mix of new high
performing meters and dated meters
with suspect accuracy. Routine, but
limited, meter accuracy testing and
meter replacement occur. Inaccuracy
volume is quantified using a mix of
reliable and less certain data.

Conditions between
6 and 8
Ongoing meter replacement and
accuracy testing result in highly
accurate customer meter population.

Testing is conducted on samples of
meters of varying age and
accumulated volume of throughput to
determine optimum replacement time
for various types of meters.

Ongoing meter
replacement and
accuracy testing result
in highly accurate
customer meter
population.

Statistically significant
number of meters are
tested in audit year.

This testing is
conducted on samples
of meters of varying
age and accumulated
volume of throughput
to determine optimum
replacement time for
these meters.

Good records of all active customer
meters exist and include as a minimum:
meter number, account
number/location, type, size and
manufacturer. Ongoing meter
replacement occurs according to a
targeted and justified basis. Regular
meter accuracy testing gives a reliable
measure of composite inaccuracy
volume for the customer meter
population. New metering technology
is embraced to keep overall accuracy
improving. Procedures are reviewed by
a third party knowledgeable in the M36
methodology.

Improvements to attain higher
data grading for "Customer
meter inaccuracy volume"
component:

Gather available meter purchase
records. Conduct testing on a small
number of meters believed to be the
most inaccurate. Review staffing
needs of the metering group and
budget for necessary resources to
better organize meter management.
to qualify for 9:

Continue efforts to manage meter
population with reliable
recordkeeping. Test a statistically
significant number of meters each
year and analyze test results in an
ongoing manner to serve as a basis
for a target meter replacement
strategy based upon accumulated
volume throughput.
to qualify for 10:

Continue efforts to
manage meter
population with reliable
recordkeeping, meter
testing and
replacement.

Evaluate new meter
types and install one
or more types in 5-10
customer accounts
each year in order to
pilot improving
metering technology.
to maintain 10:

Increase the number of meters tested
and replaced as justified by meter
accuracy test data. Continually monitor
development of new metering
technology and Advanced Metering
Infrastructure (AMI) to grasp
opportunities for greater accuracy in
metering of water flow and
management of customer consumption
data.

Systematic Data Handling
Errors:

Note: all water utilities
incur some amount of this
error. Even in water
utilities with unmetered
customer populations and
fixed rate billing, errors
occur in annual billing
tabulations. Enter a
positive value for the
volume and select a
grading.

Policies and procedures for
activation of new customer water
billing accounts are vague and lack
accountability. Billing data is
maintained on paper records which
are not well organized. No auditing
is conducted to confirm billing data
handling efficiency. An unknown
number of customers escape
routine billing due to lack of billing
process oversight.

Policy and procedures for activation
of new customer accounts and
oversight of billing records exist but
need refinement. Billing data is
maintained on paper records or
insufficiently capable electronic
database. Only periodic
unstructured auditing work is
conducted to confirm billing data
handling efficiency. The volume of
unbilled water due to billing lapses is
a guess.

Conditions between
2 and 4
Policy and procedures for new
account activation and oversight of
billing operations exist but needs
refinement. Computerized billing
system exists, but is dated or lacks
needed functionality. Periodic,
limited internal audits conducted and
confirm with approximate accuracy
the consumption volumes lost to
billing lapses.

Conditions between
4 and 6
Policy and procedures for new
account activation and oversight of
billing operations is adequate and
reviewed periodically. Computerized
billing system is in use with basic
reporting available. Any effect of
billing adjustments on measured
consumption volumes is well
understood. Internal checks of billing
data error conducted annually.

Reasonably accurate quantification of
consumption volume lost to billing
lapses is obtained.

Conditions between
6 and 8
New account activation and billing
operations policy and procedures are
reviewed at least biannually.

Computerized billing system includes
an array of reports to confirm billing
data and system functionality.

Checks are conducted routinely to
flag and explain zero consumption
accounts. Annual internal checks
conducted with third party audit
conducted at least once every five
years. Accountability checks flag
billing lapses. Consumption lost to
billing lapses is well quantified and
reducing year-by-year.

Conditions between
8 and 10
Sound written policy and procedures
exist for new account activation and
oversight of customer billing operations.

Robust computerized billing system
gives high functionality and reporting
capabilities which are utilized, analyzed
and the results reported each billing
cycle. Assessment of policy and data
handling errors are conducted internally
and audited by third party at least once
every three years, ensuring
consumption lost to billing lapses is
minimized and detected as it occurs.

Improvements to attain higher
data grading for "Systematic
Data Handling Error volume"
component:
to qualify for 2:

Draft written policy and procedures
for activating new water billing
accounts and oversight of billing
operations. Investigate and budget
for computerized customer billing
system. Conduct initial audit of
billing records by flow-charting the
basic business processes of the
customer account/billing function.
to maintain 10:

Stay abreast of customer information
management developments and
innovations. Monitor developments of
Advanced Metering Infrastructure (AMI)
and integrate technology to ensure that
customer endpoint information is wellmonitored and errors/lapses are at an economic minimum.
to qualify for 4:

Implement a reliable record keeping system for customer meter histories, preferably using electronic methods
typically linked to, or part of, the Customer Billing System or Customer Information System. Expand meter accuracy
testing to a larger group of meters.
to qualify for 4:

Finalize written policy and procedures for activation of new billing acocunts and overall billing operations
management. Implement a computerized customer billing
system. Conduct initial audit of billing records as part of this process.
to qualify for 6:

Refine new account activation and billing operations
procedures and ensure consistency with the utility policy regarding billing, and minimize opportunity for missed
billings. Upgrade or replace customer billing system for needed functionality - ensure that billing adjustments don't corrupt the value of consumption volumes. Procedurize
internal annual audit process.
to qualify for 8:

Formalize regular review of new account activation process and general billing practices. Enhance reporting capability of computerized billing system. Formalize regular auditing process to reveal scope of data handling error. Plan for periodic third party audit to occur at least once every five years.

SYSTEM DATA
to qualify for 6:

Standardize the procedures for meter recordkeeping within an electronic information system. Accelerate meter
accuracy testing and meter replacements guided by testing results.
to qualify for 8:

Expand annual meter accuracy testing to evaluate a
statistically significant number of meter makes/models.

Expand meter replacement program to replace statistically significant number of poor performing meters each year. to qualify for 10:

Close policy/procedure loopholes that allow some customer accounts to go unbilled, or data handling errors to exist.

Ensure that billing system reports are utilized, analyzed and reported every billing cycle. Ensure that internal and third party audits are conducted at least once every three years.

AWWA Free Water Audit Software v5.0 Grading Matrix 7 Page 1688 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Length of mains:

Poorly assembled and maintained
paper as-built records of existing
water main installations makes
accurate determination of system
pipe length impossible. Length of
mains is guesstimated.

Paper records in poor or uncertain
condition (no annual tracking of
installations & abandonments). Poor
procedures to ensure that new water
mains installed by developers are
accurately documented.

Conditions between
2 and 4
Sound written policy and procedures
exist for documenting new water
main installations, but gaps in
management result in a uncertain
degree of error in tabulation of mains
length.

Conditions between
4 and 6
Sound written policy and procedures
exist for permitting and commissioning
new water mains. Highly accurate
paper records with regular field
validation; or electronic records and
asset management system in good
condition. Includes system backup.

Conditions between
6 and 8
Sound written policy and procedures
exist for permitting and
commissioning new water mains.

Electronic recordkeeping such as a
Geographical Information System
(GIS) and asset management system
are used to store and manage data.

Conditions between
8 and 10
Sound written policy exists for
managing water mains extensions and
replacements. Geographic Information
System (GIS) data and asset
management database agree and
random field validation proves truth of
databases. Records of annual field
validation should be available for
review.

Improvements to attain higher
data grading for "Length of
Water Mains" component:
to qualify for 2:

Assign personnel to inventory
current as-built records and
compare with customer billing
system records and highway plans
in order to verify poorly documented
pipelines. Assemble policy
documents regarding permitting and
documentation of water main
installations by the utility and
building developers; identify gaps in
procedures that result in poor
documentation of new water main
installations.
to maintain 10:

Continue with standardization and
random field validation to improve the
completeness and accuracy of the
system.

Number of active AND inactive
service connections:

Vague permitting (of new service
connections) policy and poor paper
recordkeeping of customer
connections/billings result in
suspect determination of the
number of service connections,
which may be 10-15% in error from
actual count.

General permitting policy exists but
paper records, procedural gaps, and
weak oversight result in
questionable total for number of
connections, which may vary 5-10%
of actual count.

Conditions between
2 and 4
Written account activation policy and
procedures exist, but with some
gaps in performance and oversight.

Computerized information
management system is being
brought online to replace dated
paper recordkeeping system.

Reasonably accurate tracking of
service connection installations &
abandonments; but count can be up
to 5% in error from actual total.

Conditions between
4 and 6
Written new account activation and
overall billing policies and procedures
are adequate and reviewed
periodically. Computerized
information management system is in
use with annual installations &
abandonments totaled. Very limited
field verifications and audits. Error in
count of number of service
connections is believed to be no more
than 3%.

Conditions between
6 and 8
Policies and procedures for new
account activation and overall billing
operations are written, well-structured
and reviewed at least biannually.

Well-managed computerized
information management system
exists and routine, periodic field
checks and internal system audits are
conducted. Counts of connections
are no more than 2% in error.

Conditions between
8 and 10
Sound written policy and well managed
and audited procedures ensure reliable
management of service connection
population. Computerized information
management system, Customer Billing
System, and Geographic Information
System (GIS) information agree; field
validation proves truth of databases.

Count of connections recorded as being
in error is less than 1% of the entire
population.

Improvements to attain higher
data grading for "Number of
Active and Inactive Service
Connections" component:

Note: The number of
Service Connections
does not include fire
hydrant leads/lines
connecting the hydrant
to the water main
to qualify for 2:

Draft new policy and procedures for
new account activation and overall
billing operations. Research and
collect paper records of installations
& abandonments for several years
prior to audit year.
to maintain 10:

Continue with standardization and
random field validation to improve
knowledge of system.

Note: if customer water
meters are located
Gradings 1-9 apply if customer properties are unmetered, if customer meters exist and are located inside the customer building premises, or if the water utility owns and is responsible for the entire service connection piping from the water main to the customer building. In any of these cases the average distance between the curb stop or boundary separating utility/customer responsibility for service connection piping, and the typical first point of use (ex: faucet) or the customer meter must be quantified. Gradings of 1-9 are used to grade the validity of the means to quantify this value. (See the "Service Connection Diagram" worksheet) to qualify for 8:

Formalize regular review of new account activation and
overall billing operations policies and procedures. Launch random field checks of limited number of locations.

Develop reports and auditing mechanisms for computerized information management system.
to qualify for 10:

Close any procedural loopholes that allow installations to go undocumented. Link computerized information management
system with Geographic Information System (GIS) and
formalize field inspection and information system auditing processes. Documentation of new or decommissioned
service connections encounters several levels of checks and balances.
to qualify for 4:

Refine policy and procedures for new account activation and overall billing operations. Research computerized
recordkeeping system (Customer Information System or
Customer Billing System) to improve documentation
format for service connections.
to qualify for 6:

Refine procedures to ensure consistency with new account activation and overall billing policy to establish new service connections or decommission existing connections.

Improve process to include all totals for at least five years prior to audit year.
to qualify for 4:

Complete inventory of paper records of water main
installations for several years prior to audit year. Review policy and procedures for commissioning and
documenting new water main installation.

Either of two conditions can be met for
a grading of 10:
to qualify for 8:

Launch random field checks of limited number of locations.

Convert to electronic database such as a Geographic
Information System (GIS) with backup as justified. Develop written policy and procedures.
to qualify for 10:

Link Geographic Information System (GIS) and asset
management databases, conduct field verification of data.

Record field verification information at least annually. to qualify for 6:

Finalize updates/improvements to written policy and
procedures for permitting/commissioning new main
installations. Confirm inventory of records for five years prior to audit year; correct any errors or omissions.

AWWA Free Water Audit Software v5.0 Grading Matrix 8 Page 1689 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Vague policy exists to define the
delineation of water utility ownership
and customer ownership of the
service connection piping. Curb
stops are perceived as the
breakpoint but these have not been
well-maintained or documented.

Most are buried or obscured. Their
location varies widely from site-tosite, and estimating this distance is arbitrary due to the unknown
location of many curb stops.

Policy requires that the curb stop
serves as the delineation point
between water utility ownership and
customer ownership of the service
connection piping. The piping from
the water main to the curb stop is the
property of the water utility; and the
piping from the curb stop to the
customer building is owned by the
customer. Curb stop locations are
not well documented and the
average distance is based upon a
limited number of locations
measured in the field.

Conditions between
2 and 4
Good policy requires that the curb
stop serves as the delineation point
between water utility ownership and
customer ownership of the service
connection piping. Curb stops are
generally installed as needed and
are reasonably documented. Their
location varies widely from site-tosite, and an estimate of this distance is hindered by the availability of
paper records of limited accuracy.

Conditions between
4 and 6
Clear written policy exists to define
utility/customer responsibility for
service connection piping. Accurate,
well-maintained paper or basic
electronic recordkeeping system
exists. Periodic field checks confirm
piping lengths for a sample of
customer properties.

Conditions between
6 and 8
Clearly worded policy standardizes
the location of curb stops and meters,
which are inspected upon installation.

Accurate and well maintained
electronic records exist with periodic
field checks to confirm locations of
service lines, curb stops and
customer meter pits. An accurate
number of customer properties from
the customer billing system allows for
reliable averaging of this length.

Conditions between
8 and 10
Improvements to attain higher
data grading for "Average
Length of Customer Service
Line" component:
to qualify for 2:

Research and collect paper records
of service line installations. Inspect
several sites in the field using pipe
locators to locate curb stops.

Obtain the length of this small
sample of connections in this
manner.
to maintain 10:

Continue with standardization and
random field validation to improve
knowledge of service connection
configurations and customer meter
locations.

Average operating pressure:

Available records are poorly
assembled and maintained paper
records of supply pump
characteristics and water
distribution system operating
conditions. Average pressure is
guesstimated based upon this
information and ground elevations
from crude topographical maps.

Widely varying distribution system
pressures due to undulating terrain,
high system head loss and
weak/erratic pressure controls
further compromise the validity of
the average pressure calculation.

Limited telemetry monitoring of
scattered pumping station and water
storage tank sites provides some
static pressure data, which is
recorded in handwritten logbooks.

Pressure data is gathered at
individual sites only when low
pressure complaints arise. Average
pressure is determined by averaging
relatively crude data, and is affected
by significant variation in ground
elevations, system head loss and
gaps in pressure controls in the
distribution system.

Conditions between
2 and 4
Effective pressure controls separate
different pressure zones; moderate
pressure variation across the
system, occasional open boundary
valves are discovered that breech
pressure zones. Basic telemetry
monitoring of the distribution system
logs pressure data electronically.

Pressure data gathered by gauges or
dataloggers at fire hydrants or
buildings when low pressure
complaints arise, and during fire flow
tests and system flushing. Reliable
topographical data exists. Average
pressure is calculated using this mix
of data.

Conditions between
4 and 6
Reliable pressure controls separate
distinct pressure zones; only very
occasional open boundary valves are
encountered that breech pressure
zones. Well-covered telemetry
monitoring of the distribution system
(not just pumping at source treatment
plants or wells) logs extensive
pressure data electronically. Pressure
gathered by gauges/dataloggers at fire
hydrants and buildings when low
pressure complaints arise, and during
fire flow tests and system flushing.

Average pressure is determined by
using this mix of reliable data.

Conditions between
6 and 8
Well-managed, discrete pressure
zones exist with generally predictable
pressure fluctuations. A current fullscale SCADA System or similar realtime monitoring system exists to
monitor the water distribution system
and collect data, including real time
pressure readings at representative
sites across the system. The average
system pressure is determined from
reliable monitoring system data.

Conditions between
8 and 10
Well-managed pressure districts/zones,
SCADA System and hydraulic model
exist to give very precise pressure data
across the water distribution system.

Average system pressure is reliably
calculated from extensive, reliable, and
cross-checked data. Calculations are
reported on an annual basis as a
minimum.

Improvements to attain higher
data grading for "Average
Operating Pressure"
component:
to qualify for 2:

Employ pressure gauging and/or
datalogging equipment to obtain
pressure measurements from fire
hydrants. Locate accurate
topographical maps of service area
in order to confirm ground
elevations. Research pump data
sheets to find pump pressure/flow
characteristics
to maintain 10:

Continue to refine the hydraulic model
of the distribution system and consider
linking it with SCADA System for realtime pressure data calibration, and averaging.

Average length of customer
service line:
meters are located
outside of the customer
building next to the curb
stop or boundary
separating utility/customer
responsibility, then the
auditor should answer
"Yes" to the question on
the Reporting Worksheet
asking about this. If the
answer is Yes, the
grading description listed
under the Grading of
10(a) will be followed, with
a value of zero
automatically entered at a
Grading of 10. See the
Service Connection
Diagram worksheet for a
visual presentation of this
distance.
to qualify for 6:

Establish coherent procedures to ensure that policy for curb stop, meter installation and documentation is followed.

Gain consensus within the water utility for the establishment of a computerized information management system.
to qualify for 4:

Formalize a procedure to use pressure
gauging/datalogging equipment to gather pressure data
during various system events such as low pressure
complaints, or operational testing. Gather pump pressure and flow data at different flow regimes. Identify faulty pressure controls (pressure reducing valves, altitude
valves, partially open boundary valves) and plan to
properly configure pressure zones. Make all pressure
data from these efforts available to generate system-wide average pressure.
to qualify for 6:

Expand the use of pressure gauging/datalogging equipment to gather scattered pressure data at a representative set of sites, based upon pressure zones or areas. Utilize pump pressure and flow data to determine supply head entering each pressure zone or district. Correct any faulty pressure controls (pressure reducing valves, altitude valves, partially open boundary valves) to ensure properly configured
pressure zones. Use expanded pressure dataset from
these activities to generate system-wide average pressure. a grading of 10:
a) Customer water meters exist outside
of customer buildings next to the curb
stop or boundary separating
utility/customer responsibility for service
connection piping. If so, answer "Yes"
to the question on the Reporting
Working asking about this condition. A
value of zero and a Grading of 10 are
automatically entered in the Reporting
Worksheet .
b). Meters exist inside customer
buildings, or properties are unmetered.

In either case, answer "No" to the
Reporting Worksheet question on
meter location, and enter a distance
determined by the auditor. For a
Grading of 10 this value must be a very
reliable number from a Geographic
Information System (GIS) and
confirmed by a statistically valid number
of field checks.
to qualify for 8:

Install a Supervisory Control and Data Acquisition (SCADA) System, or similar realtime monitoring system, to monitor system parameters and control operations. Set regular
calibration schedule for instrumentation to insure data accuracy. Obtain accurate topographical data and utilize pressure data gathered from field surveys to provide
extensive, reliable data for pressure averaging.
to qualify for 10:

Annually, obtain a system-wide average pressure value from the hydraulic model of the distribution system that has been calibrated via field measurements in the water distribution system and confirmed in comparisons with SCADA System
data.
to qualify for 4:

Formalize and communicate policy delineating
utility/customer responsibilities for service connection piping. Assess accuracy of paper records by field
inspection of a small sample of service connections using pipe locators as needed. Research the potential migration to a computerized information management system to
store service connection data.
to qualify for 10:

Link customer information management system and
Geographic Information System (GIS), standardize process for field verification of data.
to qualify for 8:

Implement an electronic means of recordkeeping, typically via a customer information system, customer billing system, or Geographic Information System (GIS). Standardize the process to conduct field checks of a limited number of
locations.

AWWA Free Water Audit Software v5.0 Grading Matrix 9 Page 1690 of 3356 Grading >>> n/a 1 2 3 4 5 6 7 8 9 10
Total annual cost of operating
water system:

Incomplete paper records and lack
of financial accounting
documentation on many operating
functions makes calculation of
water system operating costs a pure
guesstimate
Reasonably maintained, but
incomplete, paper or electronic
accounting provides data to estimate
the major portion of water system
operating costs.

Conditions between
2 and 4
Electronic, industry-standard cost
accounting system in place.

However, gaps in data are known to
exist, periodic internal reviews are
conducted but not a structured
financial audit.

Conditions between
4 and 6
Reliable electronic, industry-standard
cost accounting system in place, with
all pertinent water system operating
costs tracked. Data audited
periodically by utility personnel, but not
a Certified Public Accountant (CPA).

Conditions between
6 and 8
Reliable electronic, industry-standard
cost accounting system in place, with
all pertinent water system operating
costs tracked. Data audited at least
annually by utility personnel, and at
least once every three years by thirdparty CPA.

Conditions between
8 and 10
Reliable electronic, industry-standard
cost accounting system in place, with
all pertinent water system operating
costs tracked. Data audited annually
by utility personnel and annually also by
third-party CPA.

Improvements to attain higher
data grading for "Total Annual
Cost of Operating the Water
System" component:
to qualify for 2:

Gather available records, institute
new financial accounting
procedures to regularly collect and
audit basic cost data of most
important operations functions.
to maintain 10:

Maintain program, stay abreast of
expenses subject to erratic cost
changes and long-term cost trend, and
budget/track costs proactively
Customer retail unit cost
(applied to Apparent Losses):

Customer population
unmetered, and/or only a
fixed fee is charged for
consumption.

Antiquated, cumbersome water rate
structure is used, with periodic
historic amendments that were
poorly documented and
implemented; resulting in classes of
customers being billed inconsistent
charges. The actual composite
billing rate likely differs significantly
from the published water rate
structure, but a lack of auditing
leaves the degree of error
indeterminate.

Dated, cumbersome water rate
structure, not always employed
consistently in actual billing
operations. The actual composite
billing rate is known to differ from the
published water rate structure, and a
reasonably accurate estimate of the
degree of error is determined,
allowing a composite billing rate to
be quantified.

Conditions between
2 and 4
Straight-forward water rate structure
in use, but not updated in several
years. Billing operations reliably
employ the rate structure. The
composite billing rate is derived from
a single customer class such as
residential customer accounts,
neglecting the effect of different rates
from varying customer classes.

Conditions between
4 and 6
Clearly written, up-to-date water rate
structure is in force and is applied
reliably in billing operations.

Composite customer rate is
determined using a weighted average
residential rate using volumes of water
in each rate block.

Conditions between
6 and 8
Effective water rate structure is in
force and is applied reliably in billing
operations. Composite customer rate
is determined using a weighted
average composite consumption rate,
which includes residential,
commercial, industrial, institutional
(CII), and any other distinct customer
classes within the water rate structure.

Conditions between
8 and 10
Current, effective water rate structure is
in force and applied reliably in billing
operations. The rate structure and
calculations of composite rate - which
includes residential, commercial,
industrial, institutional (CII), and other
distinct customer classes - are
reviewed by a third party
knowledgeable in the M36 methodology
at least once every five years.

Improvements to attain higher
data grading for "Customer
Retail Unit Cost" component:
to qualify for 2:

Formalize the process to implement
water rates, including a secure
documentation procedure. Create a
current, formal water rate document
and gain approval from all
stakeholders.
to qualify for 6:

Evaluate volume of water used in
each usage block by residential
users. Multiply volumes by full rate
structure.

Launch effort to fully
meter the customer
population and
charge rates based
upon water volumes
to maintain 10:

Keep water rate structure current in
addressing the water utility's revenue
needs. Update the calculation of the
customer unit rate as new rate
components, customer classes, or
other components are modified.

Variable production cost
(applied to Real Losses):

Note: if the water utility
purchases/imports its
entire water supply, then
enter the unit purchase
cost of the bulk water
supply in the Reporting
Worksheet with a grading
of 10
Incomplete paper records and lack
of documentation on primary
operating functions (electric power
and treatment costs most
importantly) makes calculation of
variable production costs a pure
guesstimate
Reasonably maintained, but
incomplete, paper or electronic
accounting provides data to roughly
estimate the basic operations costs
(pumping power costs and treatment
costs) and calculate a unit variable
production cost.

Conditions between
2 and 4
Electronic, industry-standard cost
accounting system in place. Electric
power and treatment costs are
reliably tracked and allow accurate
weighted calculation of unit variable
production costs based on these two
inputs and water imported purchase
costs (if applicable). All costs are
audited internally on a periodic basis.

Conditions between
4 and 6
Reliable electronic, industry-standard
cost accounting system in place, with
all pertinent water system operating
costs tracked. Pertinent additional
costs beyond power, treatment and
water imported purchase costs (if
applicable) such as liability, residuals
management, wear and tear on
equipment, impending expansion of
supply, are included in the unit
variable production cost, as
applicable. The data is audited at
least annually by utility personnel.

Conditions between
6 and 8
Reliable electronic, industry-standard
cost accounting system in place, with
all pertinent primary and secondary
variable production and water
imported purchase (if applicable)
costs tracked. The data is audited at
least annually by utility personnel, and
at least once every three years by a
third-party knowledgeable in the M36
methodology.

Conditions between
8 and 10
Either of two conditions can be met to
obtain a grading of 10:
1) Third party CPA audit of all pertinent
primary and secondary variable
production and water imported
purchase (if applicable) costs on an
annual basis.
or:
2) Water supply is entirely purchased
as bulk water imported, and the unit
purchase cost - including all applicable
marginal supply costs - serves as the
variable production cost. If all
applicable marginal supply costs are
not included in this figure, a grade of 10
should not be selected.

Improvements to attain higher
data grading for "Variable
Production Cost" component:
to qualify for 2:

Gather available records, institute
new procedures to regularly collect
and audit basic cost data and most
important operations functions.
to maintain 10:

Maintain program, stay abreast of
expenses subject to erratic cost
changes and budget/track costs
proactively
to qualify for 6:

Formalize process for regular internal audits of production costs. Assess whether additional costs (liability, residuals management, equipment wear, impending infrastructure
expansion) should be included to calculate a more
representative variable production cost.
to qualify for 8:

Formalize the accounting process to include direct cost components (power, treatment) as well as indirect cost
components (liability, residuals management, etc.) Arrange to conduct audits by a knowledgable third-party at least once every three years.
to qualify for 10:

Standardize the process to conduct a third-party financial audit by a CPA on an annual basis.
to qualify for 4:

Implement an electronic cost accounting system,
structured according to accounting standards for water
utilities
to qualify for 4:

Review the water rate structure and update/formalize as needed. Assess billing operations to ensure that actual billing operations incorporate the established water rate structure.
to qualify for 8:

Evaluate volume of water used in each usage block by all classifications of users. Multiply volumes by full rate structure.
to qualify for 10:

Conduct a periodic third-party audit of water used in each usage block by all classifications of users. Multiply volumes by full rate structure.
to qualify for 4:

Implement an electronic cost accounting system,
structured according to accounting standards for water
utilities
to qualify for 10:

Standardize the process to conduct a third-party financial audit by a CPA on an annual basis.

COST DATA
to qualify for 6:

Establish process for periodic internal audit of water system operating costs; identify cost data gaps and institute
procedures for tracking these outstanding costs.
to qualify for 8:

Standardize the process to conduct routine financial audit on an annual basis. Arrange for CPA audit of financial
records at least once every three years.

AWWA Free Water Audit Software v5.0 Grading Matrix 10 Page 1691 of 3356 AWWA Free Water Audit Software:

Figure 2 shows the
configuration of the customer
water meter located inside the
customer building, where Lp is
the distance from the curb stop
to the water meter.

Figure 3 shows the
configuration of an unmetered
customer building , where Lp is
the distance from the curb stop
to the first point of customer
water consumption, or, more
simply, the building line.

In any water system the Lp will
vary notably in a community of
different structures, therefore
the average Lp value is used
and this should be
approximated or calculated if a
sample of service line
measurements has been
gathered.

Figure 1
Figure 2
Figure 3
American Water Works Association.

WAS v5.0
Click for more
information
AWWA Free Water Audit Software v5.0 Service Connection Diagram 1

Page 1692 of 3356 ends

Item Name
Apparent
Losses

AUTHORIZED

CONSUMPTION
Average length of
customer service
line
Average
operating
pressure
Billed Authorized
Consumption
Billed metered
consumption
Billed unmetered
consumption
AWWA Free Water Audit Software:

All consumption that is billed and authorized by the utility. This may include both metered and unmetered consumption. See "Authorized Consumption" for more information.
= unauthorized consumption + customer metering inaccuracies + systematic data handling errors Apparent Losses include all types of inaccuracies associated with customer metering (worn meters as well as improperly sized meters or wrong type of meter for the water usage profile) as well as systematic data handling errors (meter reading, billing, archiving and reporting), plus unauthorized consumption (theft or illegal use).

NOTE: Over-estimation of Apparent Losses results in under-estimation of Real Losses. Under-estimation of Apparent Losses results in over-estimation of Real Losses.

All billed consumption which is calculated based on estimates or norms from water usage sites that have been determined by utility policy to be left unmetered.

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AWWA Free Water Audit Software v5.0 Definitions 1 Page 1693 of 3356 Item Name Description
Customer
metering
inaccuracies
Customer retail
unit cost
Infrastructure
Leakage Index
(ILI)
Length of mains

NON-REVENUE
WATER
Number of active
AND inactive
service
connections
Real Losses
Revenue Water
Service
Connection
Density
= Apparent Losses + Real Losses + Unbilled Metered Consumption + Unbilled Unmetered Consumption. This is water which does not provide revenue potential to the utility.

For instance, many larger meters have reduced accuracy at low flows. If an oversized meter is installed, most of the time the routine flow will occur in the low flow range of the meter, and a significant portion of it may not be registered. It is important to properly select and install all meters, but particularly large customer meters, size 1-inch and larger.

The ratio of the Current Annual Real Losses (Real Losses) to the Unavoidable Annual Real Losses (UARL). The ILI is a highly effective performance indicator for comparing (benchmarking) the performance of utilities in operational management of real losses. =number of customer service connections / length of mains Length of all pipelines (except service connections) in the system starting from the point of system input metering (for example at the outlet of the treatment plant). It is also recommended to include in this measure the total length of fire hydrant lead pipe. Hydrant lead pipe is the pipe branching from the water main to the fire hydrant. Fire hydrant leads are typically of a sufficiently large size that is more representative of a pipeline than a service connection. The average length of hydrant leads across the entire system can be assumed if not known, and multiplied by the number of fire hydrants in the system, which can also be assumed if not known. This value can then be added to the total pipeline length. Total length of mains can therefore be calculated as:

The annual volume lost through all types of leaks, breaks and overflows depends on frequencies, flow rates, and average duration of individual leaks, breaks and overflows.

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AWWA Free Water Audit Software v5.0 Definitions 2 Page 1694 of 3356 Item Name Description
Systematic data
handling errors
Total annual cost
of operating the
water system
Unauthorized
consumption
Apparent losses caused by accounting omissions, errant computer programming, gaps in policy, procedure, and permitting/activation of new accounts; and any type of data lapse that results in under-stated customer water consumption in summary billing reports.

Systematic Data Handling Errors result in a direct loss of revenue potential. Water utilities can find "lost" revenue by keying on this component.

Note: if the auditor selects the default value for unauthorized consumption, a data grading of 5 is automatically assigned, but not displayed on the Reporting Worksheet.

Unavoidable
Annual Real
Losses (UARL)
UARL (gallons)=(5.41Lm + 0.15Nc + 7.5Lc) xP,
or
UARL (litres)=(18.0Lm + 0.8Nc + 25.0Lc) xP
where:

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AWWA Free Water Audit Software v5.0 Definitions 3 Page 1695 of 3356 Item Name Description
Unbilled
Authorized
Consumption
Unbilled metered
consumption
Unbilled
unmetered
consumption
Convert From…
Million Gallons (US) = 3.06888329 Acre-feet
Use of Option
Buttons
Variable
production cost
(applied to Real
Losses)
Volume from own
sources
(conversion factor = 3.06888328973723)
Metered consumption which is authorized by the water utility, but, for any reason, is deemed by utility policy to be unbilled. This might for example include metered water consumed by the utility itself in treatment or distribution operations, or metered water provided to civic institutions free of charge. It does not include water supplied to neighboring utilities (water exported) which may be metered but not billed.

Converts to…..

Note that a value of zero is not permitted, since all water utilities have some volume of water in this component occurring in their system.

Enter Units:

Units and
Conversions
All consumption that is unbilled, but still authorized by the utility. This includes Unbilled Metered Consumption + Unbilled Unmetered Consumption. See "Authorized Consumption" for more information. For Unbilled Unmetered Consumption, the Free Water Audit Software provides the auditor the option to select a default value if they have not audited unmetered activities in detail. The default calculates a volume that is 1.25% of the Water Supplied volume. If the auditor has carefully audited the various unbilled, unmetered, authorized uses of water, and has established reliable estimates of this collective volume, then he or she may enter the volume directly for this component, and not use the default value. 1 The cost to produce and supply the next unit of water (e.g., $/million gallons). This cost is determined by calculating the summed unit costs for ground and surface water treatment and all power used for pumping from the source to the customer. It may also include other miscellaneous unit costs that apply to the production of drinking water. It should also include the unit cost of bulk water purchased as an import if applicable.

If a default value is selected, the user does not need to grade the item; a grading value of 5 is automatically applied (however, this grade will not be displayed).

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AWWA Free Water Audit Software v5.0 Definitions 4 Page 1696 of 3356 Item Name Description
Volume from own
sources: Master
meter and supply
error adjustment
Water exported
Water exported:

Master meter and
supply error
adjustment
Water imported
Water imported:

Master meter and
supply error
adjustment

An estimate or measure of the volume in which the Water Imported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived imported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some level of meter inaccuracy, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived metered data. Thus, a value of zero should not be entered. Enter a negative percentage or value for metered data under-registration; or, enter a positive percentage or value for metered data over-registration. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment.

An estimate or measure of the volume in which the Water Exported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived exported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some degree of error in their metered data, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived data. Thus, a value of zero should not be entered. Enter a negative percentage or value for metered data under-registration; or enter a positive percentage or value for metered data over-registration. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment. Corrections to data gaps or other errors found in the archived data should also be included as a portion of this meter error adjustment.

The Water Exported volume is the bulk water conveyed and sold by the water utility to neighboring water systems that exists outside of their service area.

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AWWA Free Water Audit Software v5.0 Definitions 5 Page 1697 of 3356 Water Audit Report for:

Reporting Year: 20/21
Data Validity Score: 70
Functional Focus
Area
Audit Data Collection
Short-term loss control
Long-term loss control
Target-setting
Benchmarking
City of Corona (CA3310037)
7/2020 - 6/2021
Water Loss Control Planning Guide
Establish/revise policies and
procedures for data collection
Refine data collection practices
and establish as routine business
process
Annual water audit is a reliable
gauge of year-to-year water
efficiency standing
Level III (51-70) Level IV (71-90)
Water Audit Data Validity Level / Score
Level I (0-25)
Evaluate and refine loss control
goals on a yearly basis
Begin to assess long-term needs
requiring large expenditure:
customer meter replacement,
water main replacement program,
new customer billing system or
Automatic Meter Reading (AMR)
system.

Begin to assemble economic
business case for long-term
needs based upon improved data
becoming available through the
water audit process.

Conduct detailed planning,
budgeting and launch of
comprehensive improvements for
metering, billing or infrastructure
management
Continue incremental
improvements in short-term and
long-term loss control
interventions
Establish long-term apparent and
real loss reduction goals (+10
year horizon)
Establish mid-range (5 year
horizon) apparent and real loss
reduction goals
Research information on leak
detection programs. Begin
flowcharting analysis of customer
billing system
Level II (26-50) Level V (91-100)
Analyze business process for
customer metering and billing
functions and water supply
operations. Identify data gaps.

Establish ongoing mechanisms
for customer meter accuracy
testing, active leakage control
and infrastructure monitoring
Refine, enhance or expand
ongoing programs based upon
economic justification
Launch auditing and loss control
team; address production
metering deficiencies
Preliminary Comparisons - can
begin to rely upon the
Infrastructure Leakage Index (ILI)
for performance comparisons for
real losses (see below table)
Performance Benchmarking - ILI
is meaningful in comparing real
loss standing
Identify Best Practices/ Best in
class - the ILI is very reliable as a
real loss performance indicator
for best in class service
For validity scores of 50 or below, the shaded blocks should not be focus areas until better data validity is achieved.

AWWA Free Water Audit Software:

Determining Water Loss Standing American Water Works Association.

WAS v5.0
AWWA Free Water Audit Software v5.0 Loss Control Planning 1

Page 1698 of 3356 ends

Target ILI Range
1 1.0 - 3.0
2 >3.0 -5.0
3 >5.0 - 8.0
Greater than 8.0
4 Less than 1.0
Once data have been entered into the Reporting Worksheet, the performance indicators are automatically calculated. How does a water utility operator know how well his or her system is performing? The AWWA Water Loss Control Committee provided the following table to assist water utilities is gauging an approximate Infrastructure Leakage Index (ILI) that is appropriate for their water system and local conditions. The lower the amount of leakage and real losses that exist in the system, then the lower the ILI value will be.

Water resources are costly to develop or
purchase; ability to increase revenues via water
rates is greatly limited because of regulation or low
ratepayer affordability.

Water Resources Considerations
Available resources are greatly limited and are
very difficult and/or environmentally unsound to
develop.

Operational Considerations
Operating with system leakage above this level
would require expansion of existing infrastructure
and/or additional water resources to meet the
demand.

General Guidelines for Setting a Target ILI
(without doing a full economic analysis of leakage control options) Water resources are believed to be sufficient to
meet long-term needs, but demand management
interventions (leakage management, water
conservation) are included in the long-term
planning. Water resources are plentiful, reliable, and easily extracted.

If the calculated Infrastructure Leakage Index (ILI) value for your system is 1.0 or less, two possibilities exist. a) you are maintaining your leakage at low levels in a class with the top worldwide performers in leakage control. b) A portion of your data may be flawed, causing your losses to be greatly understated. This is likely if you calculate a low ILI value but do not employ extensive leakage control practices in your operations. In such cases it is beneficial to validate the data by performing field measurements to confirm the accuracy of production and customer meters, or to identify any other potential sources of error in the data.

Water resources can be developed or purchased
at reasonable expense; periodic water rate
increases can be feasibly imposed and are
tolerated by the customer population.

Cost to purchase or obtain/treat water is low, as
are rates charged to customers.

Existing water supply infrastructure capability is
sufficient to meet long-term demand as long as
reasonable leakage management controls are in
place.

Superior reliability, capacity and integrity of the
water supply infrastructure make it relatively
immune to supply shortages.

Financial Considerations
AWWA Free Water Audit Software v5.0 Loss Control Planning 2

Page 1699 of 3356 ends

AWWA Free Water Audit Software:

WAS v5.0
Example Audit 1a:

Example 1a: Million Gallons: Example 1b: Million Gallons:

Performance Indicators
Example 2a: Megalitres:

Reporting Worksheet
Example 2b: Megalitres:

Reporting Worksheet
AWWA Free Water Audit Software v5.0 Example Audits 1 Page 1700 of 3356 Example Audit 1b:

AWWA Free Water Audit Software v5.0 Example Audits 2 Page 1701 of 3356 Example Audit 2a:

AWWA Free Water Audit Software v5.0 Example Audits 3 Page 1702 of 3356 Example Audit 2b:

AWWA Free Water Audit Software v5.0 Example Audits 4 Page 1703 of 3356 DEVELOPED BY: Andrew Chastain-Howley, PG*, MCSM. Black & Veatch Will J. Jernigan, P.E. Cavanaugh & Associates, P.A.

George Kunkel, P.E. Philadelphia Water Department
Alain Lalonde, P.Eng. Master Meter Canada Inc.

Ralph Y. McCord, P.E. Louisville Water Company
David A. Sayers Delaware River Basin Commission
Brian M. Skeens, P.E. CH2M HILL
Reinhard Sturm Water Systems Optimization, Inc.

John H. Van Arsdel M.E. Simpson Company, Inc.

REFERENCES: - Alegre, H., Hirner, W., Baptista, J. and Parena, R. Performance Indicators for Water Supply Services. IWA Publishing ‘Manual of Best Practice’ Series, 2000. ISBN 1 900222 272
- Kunkel, G. et al, 2003. Water Loss Control Committee Report: Applying Worldwide Best Management Practices in Water Loss Control. Journal AWWA, 95:8:65
- AWWA Water Audits and Loss Control Programs, M36 Publication, 3 rd Edition, 2009 - Service Connection Diagrams courtesy of Ronnie McKenzie, WRP Pty Ltd.

AWWA Free Water Audit Software:

Acknowledgements American Water Works Association.

WAS v5.0
www.awwa.org
AWWA Free Water Audit Software v5.0 Acknowledgements 1 Page 1704 of 3356 VERSION HISTORY:

Version: Release
Date:

Number of
Worksheets:
v1 2005/
2006 5
v2 2006 5
v3 2007 7
v4 - v4.2 2010 10
v5 2014 12
In v5, changes were made to the way Water Supplied information is entered into software, with each major component having a corresponding Master Meter Error Adjustment entry (and data grading requirement). This required changes to the data validity score calculation; v5 of the software uses a weighting system that is, in part, proportional to the volume of input components. The Grading Matrix was updated to reflect the new audit inputs and also to include clarifications and additions to the scale descriptions.

The appearance of the software was updated in v5 to make the software more user-friendly and several new features were added to provide more feedback to the user. Notably, a dashboard tab has been added to provide more visual feedback on the water audit results and associated costs of Non-Revenue Water. A comments sheet was added to allow the user to track notes, comments and to cite sources used.

In v3, the option to report volumetric units in acre-feet was added. Another new feature in v3 was the inclusion of default values for two water audit components (unbilled unmetered and unauthorized consumption). v3 also included two examples of completed audits in units of million gallons and Megalitres. Several checks were added into v3 to provide instant feedback to the user on common data entry problems, in order to help the user complete an accurate water audit. v4 (and versions 4.x) of the software included a new approach to data grading. The simple "estimated" or "measured" approach was replaced with a more granular scale (typically 1-10) that reflected descriptions of utility practices and served to describe the confidence and accuracy of the input data. Each input value had a corresponding scale fully described in the Grading Matrix tab.

Minor bug fixes resulted in the release of versions 4.1 and 4.2. A French language version was also made available for v4.2.

AWWA Free Water Audit Software v5.0 Acknowledgements 2 Page 1705 of 3356

6.0_2021_02_11
Name of Utility: VOS Volume from Own Sources
Name of Contact Person: VOSEA VOS Error Adjustment
Email: WI Water Imported
Telephone | Ext.: WIEA WI Error Adjustment
City/Town/Municipality: WE Water Exported
State / Province: WEEA WE Error Adjustment
Other State/Province: BMAC Billed Metered Authorized Consumption Country: BUAC Billed Unmetered Authorized Consumption
Audit Preparation Date: UMAC Unbilled Metered Authorized Consumption Audit Year: UUAC Unbilled Unmetered Authorized Consumption Audit Year Label: (Fiscal, Calendar, etc) SDHE Systematic Data Handling Errors Audit Period Start Date: CMI Customer Metering Inaccuracies Audit Period End Date: UC Unauthorized Consumption
Volume Reporting Units: Lm Length of mains
Water System Structure: Nc Number of service connections Water Type: Lp Average length of (private) customer service line System ID Number: AOP Average Operating Pressure
Validator Name/ID: CRUC Customer Retail Unit Charge
Validator Email: VPC Variable Production Cost
Estimated Total Population Served by Water Utility:

Color Key User input Calculated Optional default
Guidance for the Guidance for the
or
AWWA Web Resources for Water Loss Control
https://www.awwa.org/Resources-Tools/Resource-Topics/Water-Loss-Control or Items referenced in the Free Water Audit Software v6.0 on the web:

Data Grading Matrix v6.0
Example Water Audit v6.0
Water Audit Compiler v6.0
AWWA Reports on Performance Indicators
M36 Manual
If you have questions or comments regarding this software please contact us at: [email protected] Answer questions about operational practices for each
audit input, and the data validity grades will automatically populate.

Review NRW components, performance indicators and
graphical outputs to evaluate the results of the audit.

Enter notes to explain how values were calculated,
document data sources, and related information about
data management practices.

Interactive Data
Grading
951-736-2265
Corona
United States
Acre-feet
Dec 13 2022
California (CA)
Jun 30 2023
Jul 01 2022
Fiscal
2023
Enter the required data on this worksheet to calculate the water balance and data grading.

Water Balance
Loss Control
Planning
AWWA Free Water Audit Software v6.0
Enter Basic Information
Stacy Joyce
[email protected]
Table of Contents (TOC)
The current sheet. Enter contact information and basic
audit details.

Key of Input Acronyms In order of appearance in
the Worksheet
City of Corona
This spreadsheet-based water audit tool is designed to help quantify and track water losses associated with water distribution systems and identify areas for improved efficiency and cost recovery. It provides a "top-down" summary water audit format and is not meant to take the place of a full-scale, comprehensive water audit format. Auditors are strongly encouraged to refer to the most current edition of AWWA M36 Manual for Water Audits for detailed guidance on the water auditing process and targeting loss reduction levels. This tool contains several separate worksheets. Sheets can be accessed using the tabs at the bottom of the screen, or by clicking the TOC links below.

Start Page
Blank Sheet
Worksheet
Interactive Data Grading
After clicking an acronym button, answer all visible questions in the order they're presented, choosing best-fit answer
Dashboard
Notes
Acknowledgements for development of the AWWA Free
Water Audit Software v6.0.

Acknowledgements
By popular demand! A blank sheet.

The world is your canvas.

The values entered in the Worksheet automatically
populate the Water Balance.

Use this sheet to interpret the results of the audit validity score and performance indicators.

Use this sheet to understand the terms used in the audit process.

Diagrams depicting possible customer service connection line configurations.

Definitions
Service
Connection
Diagram
Choosing to enter unit of percent or volume
(applies to VOSEA, WIEA, WEEA, CMI)
Limiting
Choosing to enter default or custom input
(applies to UUAC, SDHE, UC)
choose entry option:

1.00% percent
7 Grade will populate when all visible questions
are complete for an input
The limiting criteria will be labeled along the right. If only 1 limiting criterion is shown, improving on that criterion will achieve a higher data grade. If multiple limiting criteria are shown, improving on each limiting criterion is necessary to achieve a higher data grade. A complete inventory of data grading criteria is available in the Data Grading Matrix v6.0 (see web resources)

0.25%
Retail
Potable Water
custom 75.000
volume 25.000
default
CA3310037
Damian Martinez
Use acronym buttons in IDG header to navigate among inputs. Acronym Key above.

White = needs answers, orange = complete, clear = not required. Example below. 168,751
[email protected]
choose entry option:

FWAS v6.0
AWWA Free Water Audit Software v6.0 Start Page 1

Page 1706 of 3356 ends

Water Audit Report for:

Audit Year:

All volumes to be entered as: ACRE-FEET PER YEAR
WATER SUPPLIED choose entry option:

VOS Volume from Own Sources: n g 9 26,664.749 Acre-ft/Yr n g 10 0.00% percent acre-ft/yr under-registration VOSEA WI Water Imported: n g 9 855.539 Acre-ft/Yr n g 9 0.00% percent acre-ft/yr under-registration WIEA WE Water Exported: n g 9 356.903 Acre-ft/Yr n g 7 0.00% percent acre-ft/yr under-registration WEEA 27,163.385 Acre-ft/Yr
.

AUTHORIZED CONSUMPTION
BMAC Billed Metered: n g 8 26,087.000 Acre-ft/Yr
BUAC Billed Unmetered: n g n/a 0.000 Acre-ft/Yr
UMAC Unbilled Metered: n g 10 81.080 Acre-ft/Yr choose entry option:

UUAC Unbilled Unmetered: n g 3 65.218 Acre-ft/Yr 0.25% default acre-ft/yr 24061 Default option selected for Unbilled Unmetered, with automatic data grading of 3 26,233.298 Acre-ft/Yr
WATER LOSSES 930.088 Acre-ft/Yr
Apparent Losses
Default option selected for Systematic Data Handling Errors, with automatic data grading of 3 choose entry option:

SDHE Systematic Data Handling Errors: n g 3 65.218 Acre-ft/Yr 0.25% default acre-ft/yr CMI Customer Metering Inaccuracies: n g 3 534.042 Acre-ft/Yr 2.00% percent acre-ft/yr under-registration UC Unauthorized Consumption: n g 3 65.218 Acre-ft/Yr 0.25% default acre-ft/yr Default option selected for Unauthorized Consumption, with automatic data grading of 3 664.477 Acre-ft/Yr
Real Losses
265.610 Acre-ft/Yr
930.088 Acre-ft/Yr

NON-REVENUE WATER
1,076.385 Acre-ft/Yr

SYSTEM DATA
Lm Length of mains: n g 10 813.0 miles (including fire hydrant lead lengths) Nc Number of service connections: n g 8 46,272 (active and inactive) Service connection density: 57 conn./mile main
Yes
Lp Average length of (private) customer service line: n g 10 ft (average distance between property line and meter) AOP Average Operating Pressure: n g 9 93.3 psi

COST DATA
CRUC Customer Retail Unit Charge: n g 10 $2.66
VPC Variable Production Cost: n g 8 $740.68 $/acre-ft $/yr (optional input) WATER AUDIT DATA VALIDITY TIER:
go to
dashboard
PRIORITY AREAS FOR ATTENTION TO IMPROVE DATA VALIDITY: KEY PERFORMANCE INDICATOR TARGETS:

Based on the information provided, audit reliability can be most improved by addressing the following components: OPTIONAL: If targets exist for the operational performance indicators, they can be input below:
1: Customer Metering Inaccuracies (CMI) Unit Total Losses: gal/conn/day 2: Billed Metered (BMAC) Unit Apparent Losses: gal/conn/day 3: Volume from Own Sources (VOS) Unit Real LossesA
: gal/conn/day
Unit Real LossesB: gal/mile/day
If entered above by user, targets will display on KPI gauges (see Dashboard) Are customer meters typically located at the curbstop/property line? AWWA Free Water Audit Software:

Worksheet
City of Corona
Jul 01 2022 - Jun 30 2023
Water Supplied Error Adjustments
2023 Fiscal
Real Losses:

WATER LOSSES:

Average length of customer service line has been set to zero and a data grading of 10 has been applied A weighted scale for the components of supply, consumption and water loss is included in the calculation of the Water Audit Data Validity Score *** The Water Audit Data Validity Score is in Tier IV (71-90). See Dashboard tab for additional outputs. *** $/100 cubic feet (ccf)
$46,519,641
Total Annual Operating Cost
go to start page
NON-REVENUE WATER:

If entering an
Error Adjustment,
select under- or overregistration
WATER SUPPLIED:

AUTHORIZED CONSUMPTION:

Apparent Losses:

Click 'g' to determine data validity grade Click 'n' to add notes FWAS v6.0 American Water Works Association. Copyright © 2020, All Rights Reserved. To access definitions, click the input name To edit water system info:

AWWA Free Water Audit Software v6.0 Worksheet 1

Page 1707 of 3356 ends

Interactive Data Grading Responses
2023
go to notes
vos Criteria Question Select Best-Fit Answers to All Visible Questions vos.0 Did the water utility supply any water from its own sources during the audit year? Yes vos.1 What percent of own supply volume is metered? >99% vos.2 What is the frequency of electronic calibration? Annually Limiting vos.3 What level of data transfer errors are checked as part of the electronic calibration process? Data transfer errors are checked at secondary device(s) AND tertiary device(s) vos.4 Is the most recent electronic calibration documentation available for review? Yes vos.5 What is the frequency of in-situ flow accuracy testing? Annually Limiting vos.6 Is the most recent in-situ flow accuracy testing documentation available for review? Yes vos.7 What are the total volume-weighted average results of in-situ flow accuracy testing (during or closest to audit year)? At or within ±3%
vos.8 Have testing and calibration procedures been closely scrutinized for compliance with procedures described in the AWWA M36 and/or M33 Manual(s)? Yes vos.9 Which best describes the frequency of finished water meter readings? Continuous vos.10
Which best describes the frequency of data review for anomalies/errors? These can include numbers that are outside of typical patterns, and zero or 'null' values that may reflect a gap in data recording.

Daily
FINAL DATA GRADE FOR THIS AUDIT INPUT: 9
Limiting
criteria
(see Start
Page for
details)
For questions 2-10 below: Choose the answer that applies for those meters that measure >90% of the finished water volume.

In-situ flow accuracy testing = a test process that confirms the flow measuring accuracy of the primary device (the flowmeter), in its installed location, using an independent reference volume.

Electronic calibration = a process that checks for error in the metering secondary device(s) and/or the tertiary device(s).

Secondary device can include conversion to mA, meter transmitter or similar instrumentation.

Tertiary device can include SCADA, historian or other computerized archival system. go to input Volume from Own Sources (VOS) - Data Grading Criteria AWWA Free Water Audit Software: Interactive Data Grading

SDHE CMI UC

UUAC
White = incomplete
AWWA Free Water Audit Software v6.0 Interactive Data Grading 1 of 19 Page 1708 of 3356 Interactive Data Grading Responses
go to notes
vosea Criteria Question Select Best-Fit Answers to All Visible Questions vosea.1 Are tank levels monitored automatically & recorded daily? Yes vosea.2 Are daily changes of stored water volumes in distribution system tanks included in the tabulation of the daily "Volume from Own Sources" quantity? Yes vosea.3 Is the annual net distribution storage change included in either the VOS input or the VOSEA input? Yes
vosea.4 Are the flow accuracy test and/or electronic calibration results included in the VOSEA input in the water audit? Yes, results are analyzed and a 'no-adjustment' was determined FINAL DATA GRADE FOR THIS AUDIT INPUT: 10
go to input Volume from Own Sources Error Adjustment (VOSEA) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 2 of 19 Page 1709 of 3356 Interactive Data Grading Responses
go to notes
wi Criteria Question Select Best-Fit Answers to All Visible Questions wi.0 Did the water utility import any water during the audit year? Yes wi.1 What percent of water imported is metered? >99%
wi.2 What is the frequency of electronic calibration? Annually Limiting wi.3 What level of data transfer errors are checked as part of the electronic calibration process? Data transfer errors are checked at secondary device(s) AND tertiary device(s) wi.4 Is the most recent electronic calibration documentation available? Yes wi.5 What is the frequency of in-situ flow accuracy testing? Annually Limiting wi.6 Is the most recent in-situ flow accuracy testing documentation available? Yes wi.7 What are the total volume-weighted average results of in-situ flow accuracy testing (during or closest to audit year)? At or within ±3%
wi.8 Have testing and calibration procedures been closely scrutinized for compliance with procedures described in the AWWA M36 and/or M33 Manual(s)? Yes wi.9 Which best describes the frequency of meter readings (data collection frequency as opposed to billing frequency)? Continuous
wi.10
What is the frequency of data review & correction by Exporting or Importing Utility for data gaps and/or anomalies? These can include numbers that are outside of typical patterns, and zero or 'null' values that may reflect a gap in data recording.

Daily
FINAL DATA GRADE FOR THIS AUDIT INPUT:
9 For questions 2-10 below: Choose the answer that applies for those meters that measure >90% of the water imported volume.

In-situ flow accuracy testing = a test process that confirms the flow measuring accuracy of the primary device (the flowmeter), in its installed location, using an independent reference volume.

Electronic calibration = a process that checks for error in the metering secondary device(s) and/or the tertiary device(s).

Secondary device can include conversion to mA, meter transmitter or similar instrumentation.

Tertiary device can include SCADA, historian or other computerized archival system. go to input Water Imported (WI) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 3 of 19 Page 1710 of 3356 Interactive Data Grading Responses
go to notes
wiea Criteria Question Select Best-Fit Answers to All Visible Questions wiea.1 Is an agreement in place between Exporting and Importing Utility for the purchase of water? Yes, written
wiea.2 Are meter accuracy testing or electronic calibration requirements stipulated in the water purchase agreement? Yes, and stipulated frequency as annual Limiting wiea.3 Are flow accuracy test and/or electronic calibration results used to inform the error adjustment input in the water audit? Yes, results are analyzed and a 'no-adjustment' was determined wiea.4 Who has access to the import meter readings including current and archived data? Exporting and Importing Utility FINAL DATA GRADE FOR THIS AUDIT INPUT:
9 go to input Water Imported Error Adjustment (WIEA) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 4 of 19 Page 1711 of 3356 Interactive Data Grading Responses
go to notes
we Criteria Question Select Best-Fit Answers to All Visible Questions we.0 Did the water utility export any water during the audit year? Yes we.1 What percent of water exported is metered? >99%
we.2 What is the frequency of electronic calibration? Annually Limiting we.3 What level of data transfer errors are checked as part of the electronic calibration process? Data transfer errors are checked at secondary device(s) AND tertiary device(s) we.4 Is the most recent electronic calibration documentation available? Yes we.5 What is the frequency of in-situ flow accuracy testing? Annually Limiting we.6 Is the most recent in-situ flow accuracy testing documentation available? Yes we.7 What are the total volume-weighted average results of in-situ flow accuracy testing (during or closest to audit year)? At or within ±3%
we.8 Have testing and calibration procedures been closely scrutinized for compliance with procedures described in the AWWA M36 and/or M33 Manual(s)? Yes we.9 Which best describes the frequency of meter readings (data collection frequency as opposed to billing frequency)? Continuous
we.10
What is the frequency of data review & correction by Exporting or Importing Utility for data gaps and/or anomalies? These can include numbers that are outside of typical patterns, and zero or 'null' values that may reflect a gap in data recording.

Daily
FINAL DATA GRADE FOR THIS AUDIT INPUT:
9 For questions 2-10 below: Choose the answer that applies for those meters that measure >90% of the water exported volume.

In-situ flow accuracy testing = a test process that confirms the flow measuring accuracy of the primary device (the flowmeter), in its installed location, using an independent reference volume.

Electronic calibration = a process that checks for error in the metering secondary device(s) and/or the tertiary device(s).

Secondary device can include conversion to mA, meter transmitter or similar instrumentation.

Tertiary device can include SCADA, historian or other computerized archival system. go to input Water Exported (WE) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 5 of 19 Page 1712 of 3356 Interactive Data Grading Responses
go to notes
weea Criteria Question Select Best-Fit Answers to All Visible Questions weea.1 Is an agreement in place between Exporting and Importing Utility? Yes, written weea.2 Are meter accuracy testing or electronic calibration requirements stipulated in the water purchase agreement? Yes, and stipulated frequency as annual weea.3 Are flow accuracy test and/or electronic calibration results used to inform the error adjustment input in the water audit? Yes, results are analyzed and a 'no-adjustment' was determined weea.4 Who has access to the import meter readings including current and archived data? Exporting Utility only Limiting FINAL DATA GRADE FOR THIS AUDIT INPUT:
7 go to input Water Exported Error Adjustment (WEEA) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 6 of 19 Page 1713 of 3356 Interactive Data Grading Responses
go to notes
bmac Criteria Question Select Best-Fit Answers to All Visible Questions bmac.0 Were any customers metered in the audit year? Yes bmac.1 For billed metered accounts, what % of bills are estimated in a typical billing cycle? 5% or less bmac.2
How often does the utility read its customer meters?
For systems with multiple read frequencies, select the reading frequency that describes the majority of your customers.

Monthly
bmac.3 Is the BMAC volume pro-rated to represent consumption occuring exactly during the audit period? No Limiting
bmac.4 How frequently does internal review by utility staff of the BMAC volumes occur? Every billing cycle bmac.5 What level of detail is examined in the internal review of BMAC volumes? Totals grouped by use type or customer class and specific accounts flagged for anomalous consumption bmac.6 When was the most recent billing data review by someone who is independent of the utility billing process? Within last 3 years
bmac.7 What level of detail was examined in the review by someone who is independent of the utility billing process? Third party review includes a check on a sample of accounts FINAL DATA GRADE FOR THIS AUDIT INPUT:
8 go to input Billed Metered Authorized Consumption (BMAC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 7 of 19 Page 1714 of 3356 Interactive Data Grading Responses
go to notes
buac Criteria Question Select Best-Fit Answers to All Visible Questions buac.0 Was there any billed consumption on unmetered accounts in the audit year? No buac.1 What portion of billed accounts are unmetered (% by number of accounts)? buac.2 Methodology to quantify consumption for unmetered accounts? buac.3 How frequently is unmetered customer consumption estimated? FINAL DATA GRADE FOR THIS AUDIT INPUT:
n/a
go to input Billed Unmetered Authorized Consumption (BUAC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 8 of 19 Page 1715 of 3356 Interactive Data Grading Responses
go to notes
umac Criteria Question Select Best-Fit Answers to All Visible Questions umac.0 Did the water utility have any unbilled-metered consumption in the audit year? Yes umac.1 Does the water utility policy articulate which accounts are exempt from billing? Policy includes specific exemptions umac.2 How many unbilled metered accounts exist? Monitored, count available umac.3
How often is each unbilled customer meter read?
For systems with multiple read frequencies, select the reading frequency that describes the majority of your customers.

Monthly or more frequently
umac.4 How often are unbilled metered volumes reviewed for error? Each billing cycle FINAL DATA GRADE FOR THIS AUDIT INPUT:
10 go to input Unbilled Metered Authorized Consumption (UMAC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 9 of 19 Page 1716 of 3356 Interactive Data Grading Responses
go to notes
uuac Criteria Question Select Best-Fit Answers to All Visible Questions uuac.0 On the Worksheet, the status of the default option is: Default is used because Custom Value is selected but no value has been entered uuac.1 How well-understood is the extent of unbilled unmetered use? uuac.2 Which best describes the records that are kept for events of unbilled unmetered use?
uuac.3 How is the majority of unbilled unmetered use estimated? FINAL DATA GRADE FOR THIS AUDIT INPUT:
3 This Data Grading Criteria is hidden when the 'default' input is used on the Worksheet go to input Unbilled Unmetered Authorized Consumption (UUAC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 10 of 19 Page 1717 of 3356 Interactive Data Grading Responses
go to notes
sdhe Criteria Question Select Best-Fit Answers to All Visible Questions sdhe.0 On the Worksheet, the status of the default option is: Default is used because Custom Value is selected but no value has been entered sdhe.1 Which best describes how the input was derived?
sdhe.2 Which best describes validation performed in the billing software for multipliers (conversions between unit of meter reading and unit of billing)? sdhe.3 Which best describes the policy for new service accounts to ensure there is no lapse between start of customer water usage and start of measurement/billing? sdhe.4 Which best describes auditing that takes place on the billing process? FINAL DATA GRADE FOR THIS AUDIT INPUT:
3 This Data Grading Criteria is hidden when the 'default' input is used on the Worksheet go to input Systematic Data Handling Error (SDHE) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 11 of 19 Page 1718 of 3356 Interactive Data Grading Responses
go to notes
cmi Criteria Question Select Best-Fit Answers to All Visible Questions cmi.0 Was there any metered customer usage during the audit period? Yes cmi.1 Do you test meters reactively (when triggered by customer complaint or billing/consumption flag)? Reactive testing conducted
cmi.2
For small size customer meters, which best describes the frequency of proactive testing (effort beyond when triggered by customer complaint or billing/consumption flags)?
No proactive small meter testing activity to date Limiting cmi.3 Which best describes what meters are included in the proactive small size customer meter testing activities?
cmi.4 For mid and large size customer meters, which best describes the frequency of the proactive testing program? No proactive large meter testing activity to date Limiting cmi.5 Which best describes what meters are included in the proactive mid- and large customer meter testing activities? Testing targeted to subsets of meters (ie most revenue generating or customer types) cmi.6 Which best describes how the input was derived? Meter accuracy test results or manufacturer specs are referenced but not analyzed and used directly in calculation cmi.7 Has the input derivation been reviewed by someone with expert knowledge in the M36 methodology? Yes
cmi.8 To what extent does meter replacement occur and for which meters? Annual proactive replacement of subset of meters (i.e. by age or throughput) cmi.9 Which best describes the reliability of meter installation records? Records are kept for meter installations, and they include data on installation date, type, size, and manufacturer FINAL DATA GRADE FOR THIS AUDIT INPUT:
3 go to input Customer Metering Inaccuracies (CMI) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 12 of 19 Page 1719 of 3356 Interactive Data Grading Responses
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uc Criteria Question Select Best-Fit Answers to All Visible Questions uc.0 On the Worksheet, the status of the default option is: Default is used because Custom Value is selected but no value has been entered uc.1 Which best describes how the input was derived?
uc.2 Which best describes the extent of unauthorized consumption tracking and oversight?
FINAL DATA GRADE FOR THIS AUDIT INPUT:
3 This Data Grading Criteria is hidden when the 'default' input is used on the Worksheet go to input Unauthorized Consumption (UC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 13 of 19 Page 1720 of 3356 Interactive Data Grading Responses
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Lm Criteria Question Select Best-Fit Answers to All Visible Questions Lm.1 How was the input derived? Derived directly from Mains inventory (GIS, ledger, etc) Lm.2 Are hydrant laterals included in the input derivation? Yes Lm.3 Which best describes how the Mains inventory (GIS, ledger, etc) is kept up to date? Additions or subtractions are updated in the mains inventory (GIS, ledger, etc), at least annually Lm.4 Which best describes how the Mains inventory (GIS, ledger, etc) is field validated to confirm field conditions match the inventory? Field validation is accomplished (i.e. in daily operations or specific validation projects) FINAL DATA GRADE FOR THIS AUDIT INPUT:
10 go to input Length of Mains (Lm) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 14 of 19 Page 1721 of 3356 Interactive Data Grading Responses
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Nc Criteria Question Select Best-Fit Answers to All Visible Questions Nc.1 How was the input derived? Extracted from Services inventory (GIS, billing system, etc) Nc.2 What is the count of services based on? Non-premise based, i.e. meter count, customer count Limiting Nc.3 Are inactive (but still pressurized) service lines included in the input? These may be metered or unmetered. Yes
Nc.4 Which best describes how the inventory of service connections (GIS, billing system, etc) is kept up to date? Additions or subtractions are updated in the service line inventory (GIS, billing system, etc), at least annually Nc.5 Which best describes how the inventory of service connections (GIS, billing system, etc) is field validated to confirm field conditions match the inventory? Field validation is accomplished for the entire system (i.e. in daily operations or specific validation projects) FINAL DATA GRADE FOR THIS AUDIT INPUT:
8 go to input Number of Service Connections (Nc) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 15 of 19 Page 1722 of 3356 Interactive Data Grading Responses
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Lp Criteria Question Select Best-Fit Answers to All Visible Questions Lp.0 Are customer meters typically located at the curbstop or property line? Yes Lp.1 How was the input derived?
Lp.2 Which best describes how the Customer Service Line and Meter Locations mapping is kept up to date?
Lp.3 Which best describes how the Customer Service Line mapping is validated to what is in the field?
Lp.4 Which best describes the policy to define where the utility's ownership of the service line ends, and the customer's ownership of the service line begins? FINAL DATA GRADE FOR THIS AUDIT INPUT:
10 go to input Average Length of (Private) Customer Service Line (Lp) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 16 of 19 Page 1723 of 3356 Interactive Data Grading Responses
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aop Criteria Question Select Best-Fit Answers to All Visible Questions aop.1 Which best describes checks on the boundary integrity for the system's pressure zone(s)? Normally-closed boundary valves between zones have been confirmed within the past 3 years to be fully closed aop.2 Which best describes how one-time pressure readings (i.e. from hydrants) are collected? Collected annually during routine system flushing and/or hydrant testing aop.3 Which best describes where continuous pressure data (via temporary data loggers or permanent telemetry) is collected? At zone boundary conditions, plus locations inside the zone(s) representing the full pressure profile aop.4 Which best describes how continuous pressure data is collected? Year-round data collection via permanent monitoring aop.5 How was the input derived? Calculated from field data as a weighted average, compliant with methods described in the M36 Manual Limiting FINAL DATA GRADE FOR THIS AUDIT INPUT:
9 go to input Average Operating Pressure (AOP) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 17 of 19 Page 1724 of 3356 Interactive Data Grading Responses
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cruc Criteria Question Select Best-Fit Answers to All Visible Questions cruc.0 Was any metered consumption billed on a volumetric basis in the audit period? Yes cruc.1 Which best describes the use and reliability of the current rate structure? Customer bill calculations have been checked to confirm the rate structure is correctly implemented cruc.2 Choose the option that best describes how the input was derived A volume-weighted average of all rates was calculated cruc.3 Is there any additional volumetric revenue the utility receives that depends on water meter readings, such as sewer? No
cruc.4 Has the input derivation been reviewed by someone with expert knowledge in the M36 methodology? Yes
FINAL DATA GRADE FOR THIS AUDIT INPUT:
10 go to input Customer Retail Unit Charge (CRUC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 18 of 19 Page 1725 of 3356 Interactive Data Grading Responses
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vpc Criteria Question Select Best-Fit Answers to All Visible Questions vpc.1 Choose the option that best describes how the input was derived Multiple sources of water exist, and a volume-weighted average was calculated for all sources vpc.2
Choose the option that best describes which short-run marginal costs have been included in the input, using the definitions below for reference. Short-run marginal costs can include the following:
- chemicals + power for treatment, typically applicable if the utility is producing/treating water
- power for distribution, typically applicable if pumps exist in the distribution network - water acquisition costs, typically applicable if the utility is purchasing water or incurs any extraction costs for withdrawing from a source
Some short-run marginal costs may not be applicable. The auditor should analyze the system characteristics to determine which costs are applicable for inclusion in the VPC input derivation. See also the latest AWWA M36 Manual for further guidance.

All applicable short-run marginal costs are included
vpc.3
Choose the option that best describes which long-run marginal costs have been included in the input, using the definitions below for reference. Long-run marginal costs can include the following:
- water treatment residuals management, typically applicable if solids are produced from water treatment process
- accelerated wear & tear on dynamic equipment, typically applicable if pumps exist for treatment and/or distribution, or any other equipment exists that wears out as a function of use instead of time (i.e. filter media, chemical dosing pumps, uv disinfection bulbs, etc)
- payouts for damage claims from main and service line breaks, typically applicable if damage claims are paid by the utility
- accelerated expansion of supply capacity, typically applicable if the utility is at or nearing supply capacity, or scarecity costs in water scarce areas - full cost pricing that includes all lifecycle costs and externalities (internalized or not) Some long-run marginal costs may not be applicable. The auditor should analyze the system characteristics to determine which costs are applicable for inclusion in the VPC input derivation. See also the latest AWWA M36 Manual for further guidance.

Long-run marginal costs have not been evaluated for applicability, and are not included Limiting vpc.4 Has the input derivation been reviewed by someone with expert knowledge in the M36 methodology? Yes
FINAL DATA GRADE FOR THIS AUDIT INPUT: 8
go to input Variable Production Cost (VPC) - Data Grading Criteria AWWA Free Water Audit Software v6.0 Interactive Data Grading 19 of 19 Page 1726 of 3356 0 AWWA Free Water Audit Software: Dashboard
Water Audit Report for: City of Corona Audit Year: Fiscal Jul 01 2022 - Jun 30 2023 Actual KPI result Target (see Worksheet)
1 US$ = Local
Data Validity Score: Data Validity Tier: enter current conversion rate for local currency Tier II (26-50) Tier III (51-70)
Tier IV (71-90)
Tier I (≤25)
Tier V (91-100)
Total Loss Cost Rate Apparent Loss Cost Rate Real Loss Cost Rate $/conn/year $/conn/year $/conn/year
NRW Components Summary
Unit Total Losses Unit Apparent Losses Unit Real LossesA gal/conn/day gal/conn/day gal/conn/day
Average Operating Pressure
psi
Infrastructure Leakage Index (ILI) Unit Real LossesB
dimensionless gal/mile/day
See UARL definition for additional guidance on the ILI
Real Losses Unauthorized Consumption Acre-ft/Yr gal/conn/day Systematic Data Handling Errors Unbilled Unmetered Auth Cons Customer Metering Inaccuracies Unbilled Metered Authorized Cons Apparent Losses
Real Losses
Unbilled Authorized Cons
Non-Revenue Water
0 2023
78 Tier IV (71-90)
Data Validity
gauge %iles per validated industry ranges2

0.737
See Loss Control Planning for Tier Details
Key Performance Indicators
result is below
10th %ile

4.25 go to worksheet go to grading go to references

20.88 17.9

16.62 12.8
(UARL) Unavoidable Annual Real Losses
result is below
10th %ile

22.9 1,185.0
VPC

0.2 292
result is below
10th %ile
result is below
10th %ile

5.1 93.3
CRUC
Basis of Valuation
Blended
146.3
1,076.4
$769,236
$196,732
$108,360
$1,074,327
664.5
265.6 VPC
Volume Value
Acre-ft/Yr $/Yr
0 200
400
600
800
1,000
1,200 Volume (Acre-ft/Yr)
Total Volume of NRW = 1,075
Acre-ft/Yr
$0
$200,000
$400,000
$600,000
$800,000
$1,000,000
$1,200,000
Total Cost of NRW =
$1,074,327/Yr
10th %ile
25th %ile
Median
75th %ile
90th %ile
2 3 4
2 3 4
2 3 4
2 3 4
2 3
4 American Water Works Association. Copyright © 2020, All Rights Reserved.

FWAS v6.0
2 3
4 2
3 4
Median
90 90 th %ile 90 th %ile th %ile
Median Median
Median
Median Median
Median Median
25th %ile
25th %ile
25th %ile
25th %ile 25th %ile
25th %ile
25th %ile25th %ile
75 75 th %ile 75th %ile th %ile
75th %ile 75th %ile 75th %ile
75 75 th %ile th %ile
10 10 th %ile 10 th %ile th %ile
90 10th %ile 90 th %ile 10 th %ile th %ile
90 90 th %ile 90 th %ile th %ile 10 10 th %ile 10 th %ile th %ile Guidance Information for Key Performance
AWWA Free Water Audit Software v6.0 Dashboard 1

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Table 1 Source: AWWA Water Loss Control Committee Report (2020)1 , with naming conventions updated
2020 AWWA Water Audit Method – Water Audit Outputs and Key Performance Indicators: Uses and Limitations Type Indicator Description
Suitable Purposes
Uses and Limitations Principal
Users Assessment Bench- Marking
Target- SettingPlanning Tracking
Attribute Apparent Loss Volume Calculated by Free Water Audit Software   Assess loss level Utility, Regulators Apparent Loss Cost Calculated by Free Water Audit Software   Assess cost loss level Utility, Regulators Real Loss Volume Calculated by Free Water Audit Software   Assess loss level Utility, Regulators Real Loss Cost Calculated by Free Water Audit Software   Assess loss cost level Utility, Regulators Unavoidable Annual
Real Loss (UARL)
Calculated by Free Water Audit Software   Reveal theoretical technical low level of leakage
Utility, Regulators
Volume Unit Apparent Losses (vol/conn/day) Strong and understandable indicator for multiple users.
     Used for performance
tracking and target-setting
Utility, Regulators
Unit Real LossesA
(vol/conn/day)
Strong and understandable indicator for
multiple users.
     Used for performance
tracking and target-setting
Utility, Regulators,
Policy Makers
Unit Real LossesB
(vol/pipeline length/
day)
Strong and understandable indicator for use
by utilities with low connection density.
     Data collection and
assessment of systems with
“low” connection density
Utility, Regulators,
Policy Makers
Unit Total Losses (vol/conn/day)
New KPI
Strong and understandable indicator,
suitable for high-level performance
measurement.
  High level indicator for
trending analysis. Not
appropriate for target-setting
or benchmarking
Utilities,
Customers
Infrastructure Leakage
Index (ILI)
Robust, specialized ratio KPI; can be
influenced by pressure and connection
density.
   Benchmarking after pressure
management is implemented
Utilities
Value Apparent Loss Cost
Rate (value/conn/year)
New KPI
Indicators with sufficient technical rigor.

Provide the unit financial value of each type
of loss, which is useful for planning and
assessment of cost efficiency of water loss
reduction and control interventions and
programs.
   Data collection and
assessment on AWWA
indicators or contextual
parameters to use in
conjunction with Loss Cost
Rates
Utilities,
Regulators,
Customers
Real Loss Cost Rate
(value/conn/year)
New KPI
   Utilities,
Regulators,
Customers
Validity Data Validity Tier
(DVT)
Strong indicator of water loss audit data
quality, if data has been validated. Tier
provides guidance on priority areas of
activity.
    Assess caliber of data inputs
of the water audit
Regulators,
Utilities
AWWA Free Water Audit Software v6.0 Dashboard 2

Page 1728 of 3356 ends

Water Audit Report for: City of Corona Fiscal
Audit Year: 2023 Jul 01 2022 - Jun 30 2023
General Notes:

Audit Item Notes on Input Derivation Notes on Data Validity Grading go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
Volume from
Own Sources
Error Adjustment
(VOSEA)
Electronic Calibration performed in FY 22/23 to Production Mag Meters.

AWWA Free Water Audit Software:

User Notes
Volume from
Own Sources
(VOS)
Well 3 + Well 20 + Well 21 + Temescal Desalter Effluent + Lester Production + SDO Production. All raw sources. Magnetic meters are monitored daily in WIMS and SCADA. Physical meter verification is conducted daily on about half of all production meters. Comments: Input derivation from supporting documents confirmed. Exclusion of non-potable volumes confirmed. Corona UD will be installing a new Mag meter at the Lester Plant effluent soon.

Water Imported
(WI)
Water Imported
Error Adjustment
(WIEA)
Water Exported
(WE)
(Treated) Mills WR-24 and Arlington Desalter. Magnetic meters are monitored daily in WIMS and SCADA.

Electronic Calibration performed in FY 22/23 to WE Mag Meters. Adjustments made as needed at time of annual calibration.

Norco Connection and Home Gardens. Magnetic meters are monitored daily in WIMS and SCADA.

FWAS v6.0
American Water Works Association.

AWWA Free Water Audit Software v6.0 Notes 1 Page 1729 of 3356 Audit Item Notes on Input Derivation Notes on Data Validity Grading go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
Water Exported
Error Adjustment
(WEIA)
Billed Metered
Authorized
Consumption
(BMAC)
Billed Unmetered
Authorized
Consumption
(BUAC)
Unbilled Metered
Authorized
Consumption
(UMAC)
Unbilled
Unmetered
Authorized
Consumption
(UUAC)
Systematic Data
Handling Errors
(SDHE)
Customer
Metering
Inaccuracies
(CMI)
Monthly Dead-end Hydrants =586,545 gallons. Quarterly Dead-end Hydrants = 45,458 gallons. Annual Dead-end Hydrants = 238,239 gallons. Weekly Flushing 2,485,420 gallons. Hydrant Monitoring for Water Quality = 2,223,116 gallons.

Well Start Discharges = 4,865,000 gallons.
*21,359 units to the Stein Account under contract. It equals 15,976,532 gallons for the fiscal year. Total discharges = 26,420,310 gallons or 81.08 AF Electronic Calibration performed in FY 22/23 to WE Mag Meters. Adjustments made as needed at time of annual calibration.

Provided by Customer Care's CIS Infinity V3 software. Meters are read manually monthly. Small portion of system is AMR (read monthly).

AWWA Free Water Audit Software v6.0 Notes 2 Page 1730 of 3356 Audit Item Notes on Input Derivation Notes on Data Validity Grading go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
go to
worksheet
go to
grading
Customer Retail
Unit Charge
(CRUC)
Variable
Production Cost
(VPC)
Engineering provided length of mains which includes all lateral lines. Information was calculated through GIS system. Changes are sent to GIS system modeler and corrections are field validation. City inspectors validate GIS data regularly.

Duplicates were identied therefor removed. Total length of mains + Laterals = 813 miles
Value provided by Customer Care for Drinking Water Annual Report. Total Active Connections + Total Other Connections (fire suppression, street cleaning, construction meters, temporary meters, line flushing) = 46,272 (35,915 Active + 357 Inactive)
Unauthorized
Consumption
(UC)
Length of Mains
(Lm)
Number of
Service
Connections
(Nc)
Average Length of
(private)
Customer
Service Line
(Lp)
Average
Operating
Pressure
(AOP)
Engineering provided pressures from 6 distinct pressure zones. Pressure is monitored on critical infrastructure and PRVs throughout the system and recorded on SCADA, calculated average pressure range at all zones.

Calculation based on dividing total revenue by the total volume of billed consumption.

Calculation provided by our Busines Unit division.

AWWA Free Water Audit Software v6.0 Notes 3 Page 1731 of 3356 Water Balance Water Audit Report for:

Audit Year: 2023 Jul 01 2022 - Jun 30 2023
Data Validity Tier: Tier IV (71-90)
Water Exported
(WE)
(corrected for known
errors)
Revenue Water
(Exported)
356.903 356.903
Billed Metered Consumption (BMAC)
(water exported is removed) Revenue Water
26,087.000
26,087.000 Billed Unmetered Consumption (BUAC) 26,087.000

0.000
26,233.298 Unbilled Metered Consumption (UMAC)

81.080
26,664.749 146.298 Unbilled Unmetered Consumption (UUAC)

65.218
Water Supplied Systematic Data Handling Errors (SDHE) 1,076.385 27,520.288 Apparent Losses 65.218
27,163.385 664.477 Customer Metering Inaccuracies (CMI) 534.042
Unauthorized Consumption (UC)
Water Losses 65.218
930.088 Leakage on Transmission and/or Distribution
Mains
Real Losses Not broken down
855.539 265.610 Leakage and Overflows at Utility's Storage Tanks
Not broken down
Leakage on Service Connections
Not broken down
Water Imported (WI)
(corrected for known
errors)
AWWA Free Water Audit Software
Non-Revenue Water
(NRW)
Billed Authorized Consumption
Unbilled Authorized Consumption
(corrected for known
errors)
City of Corona
Billed Water Exported
Volume from Own
Sources (VOS)
System Input
Volume
Authorized
Consumption
FWAS v6.0
American Water Works Association.

AWWA Free Water Audit Software v6.0 Water Balance 1 Page 1732 of 3356 Water Audit Report for:

Audit Year: 2023
Data Validity Tier:

Functional Focus
Area
Audit Data Collection
Short-term loss control
Long-term loss control
Target-setting
Benchmarking
AWWA Free Water Audit Software:

Determining Water Loss Standing
For validity scores of 50 or below, the shaded blocks should not be focus areas until better data validity is achieved.

Preliminary Comparisons - can begin to
rely upon with PIs for performance
comparisons for real losses
Performance Benchmarking with PIs is
meaningful in comparing real loss
standing
Identify Best Practices/ Best in class;
PIs are very reliable as real loss
performance indicators for best in class
service
Research information on leak detection
programs; Begin flowcharting analysis of
customer billing system
Tier II (26-50) Tier V (91-100)
Analyze business process for customer
metering and billing functions and water
supply operations; Identify data gaps;
improve supply metering
Stay abreast of improvements in
metering, meter reading, billing, leakage
management and infrastructure
rehabilitation
Conduct loss assessment investigations
on a sample portion of the system:
customer meter testing, leak survey,
unauthorized consumption, etc
Establish ongoing mechanisms for
customer meter accuracy testing, active
leakage control and infrastructure
monitoring
Refine, enhance or expand ongoing
programs based upon economic
justification
Launch auditing and loss control team;
address supply metering deficiencies
Evaluate and refine loss control goals on
a yearly basis
Begin to assess long-term needs
requiring large expenditure: customer
meter replacement, water main
replacement program, new customer
billing system or AMR/AMI system
Begin to assemble economic business
case for long-term needs based upon
improved data becoming available
through the water audit process
Conduct detailed planning, budgeting
and launch of comprehensive
improvements for metering, billing or
infrastructure management
Continue incremental improvements in
short-term and long-term loss control
interventions
Establish long-term apparent and real
loss reduction goals (+10 year horizon)
Establish mid-range (5 year horizon)
apparent and real loss reduction goals
City of Corona
Water Loss Control Planning Guide
Establish/revise policies and procedures
for data collection
Refine data collection practices and
establish as routine business process
Annual water audit is a reliable gauge of
year-to-year water efficiency standing
Tier III (51-70) Tier IV (71-90)
Water Audit Data Validity Tier (Score Range)
Tier I (1-25)
Tier IV (71-90)
Jul 01 2022 - Jun 30 2023 American Water Works Association. Copyright © 2020, All Rights Reserved.

FWAS v6.0
AWWA Free Water Audit Software v6.0 Loss Control Planning 1

Page 1733 of 3356 ends

Item Name
Apparent
Losses

AUTHORIZED

CONSUMPTION
Average Length
of (private)
Customer Service
Line
(Lp)
Average
Operating
Pressure
(AOP)
Billed Authorized
Consumption
AWWA Free Water Audit Software:

Definitions
Description
= billed metered + billed unmetered + unbilled metered + unbilled unmetered consumption The volume of metered and/or unmetered water taken by registered customers, the water utility's own uses, and uses of others who are implicitly or explicitly authorized to do so by the water utility; for residential, commercial, industrial and public-minded purposes.

Typical retail customers' consumption is tabulated usually from established customer accounts as billed metered consumption, or - for unmetered customers - billed unmetered consumption. These types of consumption, along with billed water exported, provide revenue potential for the water utility. Typically a lag will exist between timing for reading of supply meters and reading of customer meters. A lag-time correction should typically be calculated to account for this. Be certain to tabulate the water exported volume as a separate component and do not "double-count" it by including in the billed metered consumption component as well as the water exported component.

Unbilled authorized consumption occurs typically in non-account uses, including water for fire fighting and training, flushing of water mains and sewers, street cleaning, watering of municipal gardens, public fountains, or similar public-minded uses. Occasionally these uses may be metered and billed (or charged a flat fee), but usually they are unmetered and unbilled. In the latter case, the water auditor may use a default value to estimate this quantity, or implement procedures for the reliable quantification of these uses. This starts with documenting usage events as they occur and estimating the amount of water used in each event. (See Unbilled Unmetered Authorized Consumption) This is the average length of underground customer service line, Lp, that is owned and maintained by the customer; from the point of ownership transfer to the customer water meter, or building line (if unmetered). The quantity is one of the data inputs for the calculation of Unavoidable Annual Real Losses (UARL), which serves as the denominator of the performance indicator: Infrastructure Leakage Index (ILI). The value of Lp is multiplied by the number of customer service connections to obtain a total length of customer owned piping in the system. The purpose of this parameter is to account for the unmetered service line infrastructure that is the responsibility of the customer for arranging repairs of leaks that occur on their lines. In many cases leak repairs arranged by customers take longer to be executed than leak repairs arranged by the water utility on utility-maintained piping. Leaks run longer - and lose more water - on customer-owned service piping, than utility owned piping.

If the auditor selects "Yes" then this distance is set to zero and the data grading score for this component is set to 10.

This is the average pressure in the distribution system that is the subject of the water audit. If the water utility is compiling the water audit for the first time, the average pressure can be approximated, but with a low data grading. In subsequent years of auditing, effort should be made to improve the accuracy of the average pressure quantity. This will then qualify the value for a higher data grading.

In the absence of a hydraulic model, the average pressure may be approximated by obtaining readings of static water pressure from a representative sample of fire hydrants or other system access points evenly located across the system. A weighted average of the pressure can be assembled; but be sure to take into account the elevation of the fire hydrants, which typically exist several feet higher than the level of buried water pipelines.

If your water utility has an up-to-date and calibrated hydraulic model of the water distribution system, it can be utilized to obtain a very accurate quantity of average pressure. However using the average pressure of all “nodes” in the system model is not necessarily the most accurate way to calculate the average operating pressure. This is especially true if there are significant pressure differences throughout the system, and the “nodes” are not evenly distributed throughout the distribution system. The most accurate calculation is to obtain the average pressure that each pipe segment experiences. The way to do this is to calculate the pressure at each end of the pipe. Then calculate the average of those two values and multiply this average value by the length of that pipe.

This must be calculated for all pipe segments in the model. Finally calculate the sum of all of these values and and divide by the total pipe length. This effectively calculates a weighted average of pressure over the total pipe length. For low density systems (<32 connections/mile), average mains pressures at the service connection or curb stop may have greater influence and should be considered.

All consumption that is billed and authorized by the utility. This may include both metered and unmetered consumption. See "Authorized Consumption" for more information.
= systematic data handling errors + customer metering inaccuracies + unauthorized consumption Apparent Losses include all types of inaccuracies associated with customer metering (worn meters as well as improperly sized meters or wrong type of meter for the water usage profile) as well as systematic data handling errors (meter reading, billing, archiving and reporting), plus unauthorized consumption (theft or illegal use).

NOTE: Over-estimation of Apparent Losses results in under-estimation of Real Losses. Under-estimation of Apparent Losses results in over-estimation of Real Losses. A
FWAS v6.0 American Water Works Association. Copyright © 2020, All Rights Reserved.

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AWWA Free Water Audit Software v6.0 Definitions 1 Page 1734 of 3356 Item Name Description
Billed Metered
Authorized
Consumption
(BMAC)
Billed Unmetered
Authorized
Consumption
(BUAC)
Customer
Metering
Inaccuracies
(CMI)
Customer Retail
Unit Charge
(CRUC)
Infrastructure
Leakage Index
(ILI)
Apparent water losses caused by the collective under-registration of customer water meters. Many customer water meters gradually wear as large cumulative volumes of water are passed through them over time. This causes the meters to under-register the flow of water. This occurrence is common with smaller residential meters of sizes 5/8-inch and 3/4 inch after they have registered very large cumulative volumes of water, which generally occurs only after periods of years. For meters sized 1-inch and larger - typical of multi-unit residential, commercial, institutional and industrial accounts - meter under-registration can occur from wear or from the improper application of the meter; i.e. installing the wrong type of meter or the wrong size of meter, for the flow pattern (profile) of the consumer. For instance, many larger meters have reduced accuracy at low flows. If an oversized meter is installed, most of the time the routine flow will occur in the low flow range of the meter, and a significant portion of it may not be registered. It is important to properly select and install all meters, but particularly large customer meters, size 1-inch and larger.

Note that a value of zero will be accepted but is not recommended, as all metered systems tend to have some degree of inaccuracy. A positive value should be entered. A value of zero in this component is generally valid only if the water utility does not meter its customer population.

The formula for caculating a volume of CMI from a percentage input is as follows: CMI volume = (BMAC+UMAC)/(1-CMI%)-(BMAC+UMAC) The Customer Retail Unit Charge represents the volumetric portion of the total charges that customers pay for water service. The CRUC does not include fixed charges. This unit charge cost is applied routinely to the components of Apparent Loss, since these losses represent water reaching customers but not (fully) paid for. Since most water utilities have a rate structure that includes a variety of different charges costs based upon class of customer, a volumeweighted average of water sold at each unique rate should be calculated to determine a single composite charge that should be entered into this cell. Finally, the weighted average charge should also include additional charges for sewer, storm water or biosolids processing, but only if these charges are based upon the volume of potable water consumed.

For water utilities in regions with limited water resources and a questionable ability to meet the drinking water demands in the future, the Customer Retail Unit Charge Cost might also be applied to value the Real Losses; instead of applying the Variable Production Cost to Real Losses. In this way, it is assumed that every unit volume of leakage reduced by leakage management activities will be sold to a customer.

Note: the Free Water Audit Software allows the user to select the units that are charged to customers (either $/1,000 gallons, $/hundred cubic feet, or $/1,000 litres) and automatically converts these units for purpose of calculating Apparent Loss valuations. The monetary units are United States dollars, $.

The ratio of the Current Annual Real Losses (Real Losses) to the Unavoidable Annual Real Losses (UARL). This performance indicator is dimensionless.

NOTES ON THE UARL AND ILI:

1. This Free Water Audit Software version 6 presents the calculated UARL and ILI for systems of all sizes and all pressures. Some published research is now available on predicting how UARL is likely to be modified when modeling low leakage limits in systems that are very small (< 3000 conn), or have very low average pressures, or have very high pressures (aka boundary cases). Inherent over- or under- estimation of UARL volume may exist in these boundary cases, as they operate at or near the limits of the UARL model assumptions. More widespread application and understanding of system specific corrections to the UARL model in these boundary cases is now likely to occur, but are not included in the FWAS at the time of this publication. Caution is advised when using the standard UARL modeled value (and subsequently the ILI) for boundary cases. In boundary cases, the ILI may still be considered a general Performance Indicator, but not used as an absolute performance measurement or for benchmark comparisons.

2. The UARL term is based on average operating pressure in a given audit year, and a utility's current pressure conditions may not be optimized. Thus, ILI should always be interpreted with some measure of pressure, and only used for tracking progress if all justifiable pressure management has already been completed.

All billed consumption which is calculated based on estimates or norms from water usage sites that have been determined by utility policy to be left unmetered.

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AWWA Free Water Audit Software v6.0 Definitions 2 Page 1735 of 3356 Item Name Description
Length of Mains
(Lm)

NON-REVENUE
WATER
Number of
Service
Connections
(Nc)
Real Losses
Revenue Water
Service
Connection
Density
Systematic Data
Handling Errors
(SDHE)
Total annual
operating cost
(optional input)
Physical water losses from the pressurized system (water mains and customer service connections) and the utility’s storage tanks, up to the point of customer consumption. In metered systems this is the customer meter, in unmetered situations this is the first point of consumption (stop tap/tap) within the property.

The annual volume lost through all types of leaks, breaks and overflows depends on frequencies, flow rates, and average duration of individual leaks, breaks and overflows.
*This input has been made optional, as it is no longer used in calculating a Performance Indicator. Auditors are welcome to continue to track this input as desired.* These costs include those for operations, maintenance and any annually incurred costs for long-term upkeep of the drinking water supply and distribution system. It should include the costs of day-to-day upkeep and long-term financing such as repayment of capital bonds for infrastructure expansion or improvement. Typical costs include employee salaries and benefits, materials, equipment, insurance, fees, administrative costs and all other costs that exist to sustain the drinking water supply. Depending upon water utility accounting procedures or regulatory agency requirements, it may be appropriate to include depreciation in the total of this cost. This cost should not include any costs to operate wastewater, biosolids or other systems outside of drinking water.

Apparent losses caused by accounting omissions, errant computer programming, gaps in policy, procedure, and permitting/activation of new accounts; and any type of data lapse that results in under-stated customer water consumption in summary billing reports. Systematic Data Handling Errors occur as a customer consumption volume and can result in a direct loss of revenue potential. Water utilities can find "lost" revenue by keying on this component.

Utilities typically measure water consumption volumes registered by water meters at customer premises. The meter should be read routinely (ex: monthly) and the data transferred to the Customer Billing System, which generates and sends a bill to the customer. Data Transfer Errors result in the registered consumption volume value being less than the actual consumption volume, creating an apparent loss. Such error might occur from illegible and mis-recorded hand-written readings compiled by meter readers, inputting an incorrect meter register unit conversion factor in the automatic meter reading equipment, or a variety of similar errors.

Apparent losses also occur from Data Analysis Errors in the archival and data reporting processes of the Customer Billing System. Inaccurate estimates used for accounts that fail to produce a meter reading are a common source of error. Billing adjustments may award customers a rightful monetary credit, but do so by creating a negative value of consumption volume, thus under-stating the actual consumption. Account activation lapses may allow new buildings to begin using water for months without meter readings and billing. Poor permitting and construction inspection practices can result in a new building water service commencing without a billing account, a water meter and meter reading; i.e., the customer is unknown to the utility's billing system. Close auditing of the permitting, metering, meter reading, billing and reporting processes of the water consumption data trail can uncover data management gaps that create volumes of systematic data handling error. Utilities should routinely analyze customer billing records to detect data anomalies and quantify these losses. For example, a billing account that registers zero consumption for two or more billing cycles should be checked to explain why usage has seemingly halted. Given the revenue loss impacts of these losses, water utilities are well-justified in providing continuous oversight and timely correction of data transfer errors & data handling errors.

If the water auditor has not yet gathered detailed data or assessment of systematic data handling error, it is recommended that the auditor apply the default value of 0.25% of the Billed Authorized Consumption volume. However, if the auditor has investigated the billing system and its controls, and has well validated data that indicates the volume from systematic data handling error is substantially higher or lower than that generated by the default value, then the auditor should enter a quantity that was derived from the utility investigations and select an appropriate grading. Negative or zero values are not allowed for this audit component.

Note: occasionally billed consumption volumes for a customer account may be over-stated due to issues of double-counting an account or applying an overstated meter multiplier. The possibility of such occurrences should be explored in the data validation process, particularly if billed authorized consumption volumes for the year, or for any sub-group of customers (by classification or meter size), appears to be inordinately high. It is recommended to correct any such errors in the billed consumption total for the year, rather than consider these volumes part of Systematic Data Handling Error. =number of customer service connections / length of mains Length of all pipelines (except service connections) in the system starting from the point of system input metering (for example at the outlet of the treatment plant). It is also recommended to include in this measure the total length of fire hydrant lead pipe. Hydrant lead pipe is the pipe branching from the water main to the fire hydrant. Fire hydrant leads are typically of a sufficiently large size that is more representative of a pipeline than a service connection. The average length of hydrant leads across the entire system can be assumed if not known, and multiplied by the number of fire hydrants in the system, which can also be assumed if not known. This value can then be added to the total pipeline length. Total length of mains can therefore be calculated as:

Number of customer service connections, extending from the water main to supply water to a customer. This includes the actual number of pressurized piping connections, including fire connections, whether active or inactive. This may differ substantially from the number of customers (or number of accounts).

Note: this number does not include the pipeline leads to fire hydrants. The total length of piping supplying fire hydrants should be included in the "Length of mains" input, and excluded from the Number of service connections input.

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AWWA Free Water Audit Software v6.0 Definitions 3 Page 1736 of 3356 Item Name Description
Unauthorized
Consumption
(UC)
Unbilled
Authorized
Consumption
Unbilled Metered
Authorized
Consumption
(UMAC)
Unbilled
Unmetered
Authorized
Consumption
(UUAC)
Unavoidable
Annual Real
Losses (UARL)
The UARL is a theoretical reference value representing the technical low limit of leakage for well managed systems in good condition, with aggressive active leakage control. It is a key variable in the calculation of the Infrastructure Leakage Index (ILI).

UARL (gallons) = (5.41Lm + 0.15Nc + 7.5Lc) x P x 365 d/year, or
UARL (litres) = (18.0Lm + 0.8Nc + 25.0Lc) x P x 365 d/year where:

Lm = length of mains (miles or kilometres)
Nc = number of customer service connections
Lp = the average length of customer service connection piping (feet or metres) (see the Worksheet "Service Connection Diagram" for guidance on deterring the value of Lp) Lc = total length of customer service connection piping (miles or km) Lc = Nc X Lp (miles or kilometres)
P = Average operating pressure (psi or metres) (see Average Operating Pressure definition) NOTES ON THE UARL AND ILI:

Any kind of Authorized Consumption which is neither billed nor metered. This component typically includes water used in activities such as fire fighting, flushing of water mains and sewers, street cleaning, fire flow tests conducted by the water utility, etc. In most water utilities it is a small component.

This component does NOT include water supplied to neighboring utilities (water exported) which is unmetered and unbilled – an unlikely case. Also, if any potable water used at a water treatment plant is tapped from a location upstream of the meter(s) used to determine the Volume from Own Sources in the audit, this is outside of the boundary of the audit and should therefore not be included as part of Unbilled, Unmetered Authorized Consumption.

This component has many sub-components of water use which may not yet be quantified. The default is 0.25% of the Billed Authorized Consumption volume (BMAC + BUAC), and is recommended for temporary use if customized estimates are not yet available, with recommendation to begin tracking and estimating these volumes for the next audit.

Note that a value of zero is not permitted, since all water utilities likely have some volume of water in this component occurring in their system.

Units and
Conversions
All consumption that is unbilled, but still authorized by the utility. This includes Unbilled Metered Authorized Consumption (UMAC) + Unbilled Unmetered Authorized Consumption (UUAC). See "Authorized Consumption" for more information.

Metered consumption which is authorized by the water utility, but, for any reason, is deemed by utility policy to be unbilled. This might for example include metered water consumed by the utility itself in treatment or distribution operations, or metered water provided to civic institutions free of charge. It does not include water supplied to neighboring utilities (water exported) which may be metered but not billed.

Includes water illegally withdrawn from fire hydrants, illegal connections, bypasses to customer consumption meters, or tampering with metering or meter reading equipment; as well as any other ways to receive water while thwarting the water utility's ability to collect revenue for the water. Unauthorized consumption results in uncaptured revenue and creates an error that understates customer consumption. In most water utilities this volume is low and, if the water auditor has not yet gathered detailed data for these loss occurrences, it is recommended to use the default value of 0.25% of the Billed Authorized Consumption volume. However, if the auditor has investigated unauthorized occurrences, and has well validated data that indicates the volume from unauthorized consumption is substantially higher or lower than that generated by the default value, then the auditor should enter a quantity that was derived from the utility investigations. Note that a value of zero will not be accepted since all water utilities tend to have some volume of unauthorized consumption occurring in their system. Find
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AWWA Free Water Audit Software v6.0 Definitions 4 Page 1737 of 3356 Item Name Description
Convert From…
Million Gallons (US) = 306.888329 Acre-feet
Variable
Production Cost
(VPC)
(applied to Real
Losses)
Volume from Own
Sources
(VOS)
Volume from own
sources: error
adjustment
Water Exported
(WE)
Water Exported:

Error Adjustment
(WEEA)
Water Imported
(WI)
100
An estimate or measure of the volume by which the Water Exported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived exported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some degree of error in their metered data, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived data. Enter a positive percentage or volume, then select 'under-registration' or 'over-registration' from the drop-down immediately adjacent. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment. Corrections to data gaps or other errors found in the archived data should also be included as a portion of this meter error adjustment. See Water Supplied Error Adjustments definition for guidance on how to calculate this input.

The cost to produce and supply the next unit of water (e.g., $/million gallons). This cost can include both short-run and long-run marginal costs. See the VPC data grading questions on IDG tab for examples of short-run and long-run marginal costs that may be included.

It is common to apply the VPC unit cost to the volume of Real Losses. However, if water resources are strained and the ability to meet future drinking water demands is in question, then the water auditor may be justified in applying the Customer Retail Unit Charge to the Real Loss volume, rather than applying the Variable Production Cost.

Water treatment plants are also often supplied potable drinking water and therefore are a “customer” of the water utility. If the service connection line serving the water treatment plant is downstream of treated water effluent flowmeters, this water should be metered and billed as billed authorized consumption. In this case, this volume of water does not enter into any calculations for Volume from Own Sources. If the service connection line suppling potable water to the treatment plant is upstream of treated water effluent flowmeters, then this water is considered “process” water and included with calculations accounting for process water use.

If metering exists only at the raw water source, an adjustment for water used in the treatment process should be included to account for water consumed in treatment operations such as filter backwashing, basin flushing and cleaning, plant potable water consumption (if the supply is drawn upstream of effluent flowmetering.) and similar uses. If the audit is conducted for a wholesale water agency that sells untreated water, then this quantity reflects the measure of the raw water, typically metered at the source.

The Water Imported volume is the bulk water purchased to become part of the Water Supplied volume. Typically this is water purchased from a neighboring water utility or regional water wholesale supplier, and is metered at the custody transfer point of interconnection between the two water utilities. Usually the meter(s) are owned by the water supplier selling the water to the utility conducting the water audit. The water supplier selling the bulk water usually charges the receiving utility based upon a wholesale water rate.

An estimate or measure of the degree of inaccuracy that exists in the master (production) meters measuring the annual Volume from own Sources, and any error in the data trail that exists to collect, store and report the summary production data. This adjustment is a weighted average number that represents the collective error for all master meters for all days of the audit year and any errors identified in the data trail. Meter error can occur in different ways. A meter or meters may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Data error can occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some degree of inaccuracy in master meters and data errors in archival systems are common. Enter a positive percentage or volume, then select 'under-registration' or 'over-registration' from the drop-down immediately adjacent. See Water Supplied Error Adjustments definition for guidance on how to calculate this input.

The Water Exported volume is the bulk water conveyed or sold by the water utility to neighboring water systems that exists outside of their service area.

Typically this water is metered at the custody transfer point of interconnection between the two water utilities. Usually the meter(s) are owned by the water utility that is selling or transfering the water: i.e. the exporter. If the water utility who is compiling the annual water audit sells or transfers bulk water in this manner, they are an exporter of water.

Note: The Water Exported volume is typically sold to wholesale customers who are charged a wholesale rate that is different than retail rates charged to the retail customers existing within the service area. Many state regulatory agencies require that the Water Exported volume be reported to them as a quantity separate and distinct from the retail customer billed consumption. For these reasons - and others - the Water Exported volume is always quantified separately from Billed Authorized Consumption in the standard water audit. Be certain not to "double-count" this quantity by including it in both the Water Exported box and the Billed Metered Consumption box of the water audit Worksheet. This volume should be included only in the Water Exported box.

Enter Units:
(conversion factor = 3.0689)
Converts to…..

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AWWA Free Water Audit Software v6.0 Definitions 5 Page 1738 of 3356 Item Name Description
Water Imported:

Error Adjustment
(WIEA)
WATER LOSSES = apparent losses + real losses
= water supplied - authorized consumption
Water Losses are the difference between Water Supplied and Authorized Consumption. Water losses can be considered as a total volume for the whole system, or for partial systems such as transmission systems, pressure zones or district metered areas (DMA), if one of these configurations are the basis of the water audit.

An estimate or measure of the volume by which the Water Imported volume is incorrect. This adjustment is a weighted average that represents the collective error for all of the metered and archived imported flow for all days of the audit year. Meter error can occur in different ways. A meter may be inaccurate by under-registering flow (did not capture all the flow), or by over-registering flow (overstated the actual flow). Error in the metered, archived data can also occur due to data gaps caused by temporary outages of the meter or related instrumentation. All water utilities encounter some level of meter inaccuracy, particularly if meters are aged and infrequently tested. Occasional errors also occur in the archived metered data. Enter a positive percentage or volume, then select 'under-registration' or 'over-registration' from the drop-down immediately adjacent. If regular meter accuracy testing is conducted on the meter(s) - which is usually conducted by the water utility selling the water - then the results of this testing can be used to help quantify the meter error adjustment. See Water Supplied Error Adjustments definition for guidance on how to calculate this input.

Disclaimer: The guidance provided below should be considered general, representing a typical approach to determining Error Adjustment. Supply metering setups, metering technologies, instrumentation, data recording/archival, and data management systems can vary significantly from one water utility to the next.

Inherent margins of error will also vary among different testing and calibration methods and the measurement systems being tested. Other factors that may be important include, but are not limited to, frequency of testing and calibration practices, data communication outages in the audit period, tested flowrates versus typical operating flowrates, and test durations. All of these factors must be considered when assessing Error Adjustment for the Water Supplied inputs. Each specific situation should be carefully analyzed to determine the most appropriate approach for determining the Error Adjustment to input, if any.

General: For the Water Supplied inputs, there are three typical sources of error that may warrant an Error Adjustment on the Worksheet.

1. Meter error: measurement inaccuracy in the meter(s) used to derive the input volume, typically identified through in-situ flow accuracy testing. Applicable for VOS, WI and WE. If no such testing has been performed, adjustment for meter error is not typically recommended.

2. Data transfer error: inaccuracy in archived volumes, typically due to gaps in data, programming errors impacting unit conversions, and/or programming errors impacting totalization of measured volumes over the audit period. Applicable for VOS, WI and WE. These errors are typically identified through electronic calibration to verify data transfer at the secondary device (i.e. conversion to mA, meter transmitter or similar instrumentation) and/or the tertiary device (i.e. SCADA, historian or other computerized archival system).

3. Net distribution storage change: The difference between end of audit period and beginning of audit period for total finished water stored, downstream of the system input meter(s). Typically applicable for VOS or WI. This volume is typically derived by comparing distribution storage tank water levels at end and beginning of the water audit period and using approximate tank geometry to convert levels to volumes.

Derivation Guidance:

If an Error Adjustment input is being calculated as a volume, each source of error (described above) may be separately calculated, with careful consideration of under- vs over-registration, then added together to determine the composite volume to input. The composite input should be entered on the Worksheet as a positive number, then under- or over-registration selected on the adjacent dropdown.

If an Error Adjustment input is being calculated as a percent, some very general guidance for calculating each error source (described above) is provided below. The auditor is again cautioned that each specific water supply setup needs to be evaluated closely as noted in the Disclaimer. Refer to the latest AWWA M36 Manual for additional discussion and guidance on this matter.

1. Meter error: If in-situ flow accuracy testing has been performed, and inherent testing method error is understood, first the meter accuracy % may be determined as follows:
meter accuracy % = System input meter(s) volume / Reference volume Then, the meter error % may be determined as follows:
meter error % = meter accuracy % - 100%

2. Data transfer error: If electronic calibration at the secondary (i.e. conversion to mA, meter transmitter or similar instrumentation) and/or tertiary (i.e. SCADA, historian or other computerized archival system) devices has been performed, first the data transfer accuracy % may be determined as follows:
data transfer accuracy % = Tertiary device volume / Reference volume (typically at Secondary device)

Then, the data transfer error % may be determined as follows:
data transfer error % = data transfer accuracy % - 100% If no error is identified, or if electronic calibration has not been performed, or if no secondary or tertiary devices exist, a data transfer error % adjustment is not typically recommended.

3. Net distribution storage change. If meter error and/or data transfer error are being calculated as a %, it is recommended to make the adjustment for net distribution storage change as a volume adjustment, directly in the VOS or WI input, as applicable.

The final step is to add meter error % and data transfer error %:

Error Adjustment % = meter accuracy % + data transfer error % If the total Error Adjustment % calculates out as a negative number, it represents an under-registration. Vice versa, if positive. The composite input should be entered on the Worksheet as a positive number, then under- or over-registration selected on the adjacent dropdown.

Water Supplied
Error
Adjustments
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AWWA Free Water Audit Software v6.0 Definitions 6 Page 1739 of 3356 #REF!
AWWA Free Water Audit Software:

Figure 2 shows the
configuration of the customer
water meter located inside the
customer building, where Lp is
the distance from the curb stop
to the water meter.

Figure 3 shows the
configuration of an unmetered
customer building , where Lp is
the distance from the curb stop
to the first point of customer
water consumption, or, more
simply, the building line.

In any water system the Lp will
vary notably in a community of
different structures, therefore
the average Lp value is used
and this should be approximated
or calculated if a sample of
service line measurements has
been gathered.

American Water Works Association.

Page 1740 of 3356 ends

Corona City CouncilJune 17, 2026

Corona City Council
June 17, 2026