Water Loss Manual

Texas Water Development BoardP.O. Box 13231Austin, Texas 78711-3231

May 2005

TABLE OF CONTENTS

Page I. INTRODUCTION.....................................................................................................1 II. WATER AUDIT IMPLEMENTATION ..................................................................2 III. TOP DOWN AUDITS ..............................................................................................2 IV. BOTTOM UP AUDITS ............................................................................................2 V. DEFINITION OF TERMS........................................................................................2 VI. UNDERSTANDING THE METHODOLOGY........................................................3 VII. WATER AUDIT WORKSHEET..............................................................................5 VIII. WATER AUDIT WORKSHEET INSTRUCTIONS................................................9 IX. WATER BALANCE...............................................................................................14

X. PERCENTAGES VS VOLUME OF WATER .......................................................14 XI. WATER LOSS AUDIT PROGRAM......................................................................15 XII. METER SELECTION AND INSTALLATION.....................................................15 XIII. METHODS TO LOCATE AND MINIMIZE WATER LOSS ...............................18 XIV. PERFORMANCE INDICATORS ..........................................................................21 XV. CONCLUSION.......................................................................................................22 XVI. RESOURCES..........................................................................................................23 XVII. FORMS AND TABLE............................................................................................25

XVIII. INFORMATION HANDOUT ................................................................................35

This publication of the Water Loss Manual was developed by the Texas Water Development Board (TWDB) in response to HB 3338 passed by the 78th Legislature, that requires all retail public water suppliers to Texas to file a water loss audit report once every five years. This document was developed by Texas Water Development Board staff Mark Mathis. Special thanks to Andrew Chastain-Howley, George Kunkel and Julian Thornton for their knowledge and input. Additional information regarding water loss can be found at the TWDB website, www.twdb.state.tx.us or by calling Mark Mathis with the TWDB at 512-463-0987.

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TEXAS WATER DEVELOPMENT BOARD

WATER LOSS MANUAL

INTRODUCTION All across Texas there are water availability concerns that invite utilities to perform better as water stewards. Water loss reduction is twofold. As water loss decreases, conservation and water supply is increased. Local communities will be more apt to conserve once they see their water utility participating in the conservation process. An audit from an accounting perspective is simply confirming and compiling information on the entity as a whole. Many utilities have not previously conducted water audits and those that have, only compare water produced to water sold. Water audits have not been widely utilized in the water industry, mainly due to the low cost of water supply, treatment and distribution. However, with rising supply costs and the general public becoming more informed about water availability, the industry is recognizing the need to minimize water loss. One could ask hundreds of utilities across the nation and they would all give a different definition of Unaccounted for Water (UFW). Water loss and UFW have been used interchangeably. If water was not accounted for then it was simply classified as “water loss.” The new method introduced in this manual eliminates UFW from being used. Now there is a category for every type of use. The new methodologies being used which enable water utilities to operate very efficiently. Based on the International Water Association’s (IWA) methodology which has been used all over the world and recently in the United States, these methods are proven to work. They eliminate UFW, but also and the end results direct focus to problem areas. This methodology implements new terminology that will need to be thoroughly understood: corrected input volume; authorized consumption; apparent loss and real loss. The Texas Water Development Board (TWDB) recommends this methodology for all utilities across Texas. This method is being used for the implementation of HB 3338, which requires all water utilities statewide to conduct a water audit once every five years. As utilities learn and implement the methods that are proven to minimize water loss, they will begin to view water loss with a new understanding.

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WATER AUDIT IMPLEMENTATION The term “water loss” is now broken down into two separate categories that enable the utility to put distribution loss into the real loss category and meter inaccuracies and theft into apparent loss. With the current system of putting all types of loss into one category, the utility could not focus or direct its resources to the area of the loss. The utility was simply guessing as to the area needing assistance. Implementing audits into the business cycle will enable the utility’s operation to become more efficient with each passing year. Utilities need to understand that it may take time before results can be expected from a meter replacement program and/or leak detection program. Initially, smaller utilities may see that the implementation of audits will warrant a few estimates. Over a several year period, these smaller systems will see that obtaining valid data assists them in lowering their losses. TOP DOWN AUDITS Top down audits are paper audits that utilize data the utility should already have without additional fieldwork. These are referred to as “desk top” exercises. Data is transferred from other reports to the water audit form, enabling the utility to see which areas warrant more fieldwork. This type of audit is typically less expensive than a more thorough bottom up audit. Top down audits are the method chosen for implementing the water loss reporting requirements of HB 3338. BOTTOM UP AUDITS This is the second part of the audit process. The utility confirms the data used in the top down portion. Bottom up audits are usually implemented only after the utility has a thorough understanding of the findings from the top down audit. Bottom up audits are more costly due to the amount of time, staff hours, and detailed work that is required. They include each aspect of the utility: billing records, distribution system, accounting principles, and all other programs within the utility. This audit will identify all internal issues that are preventing the utility from achieving high efficiency. Utilities can implement this method once they have completed several top down audits. DEFINITION OF TERMS Own Water – Water that has come from a utility’s own sources, such as well fields, water rights, or a reservoir. Purchased Water – Water that has been purchased or bought from another entity. Input Volume/Water Delivery – All the water that is purchased, owned, or obtained by interconnects (water imported). Water Supplied – Defined as system input volume minus water exported. Water Exported – Water that is transferred out of the system to a buyer where revenue is received. Master Meter Accuracy – Obtained by calibrating master meters. The utility checks the accuracy of the master meters, and then either adds or subtracts this number, depending on whether the meter was under or over-registering, from system input volume to determine the amount of water that was actually put into the distribution system. Corrected Input Volume - The sum of Master Meter Accuracy and System Input Volume is the amount of water that was actually put into the system.

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Authorized Consumption – Consists of four sub-categories that include all authorized water use:

1. Billed Metered – The water that has been sold and for which compensation from customers has been received.

2. Billed Unmetered – For all uses that have not been metered but compensation is received. 3. Unbilled Metered – For all uses that have been metered and no compensation is received

(used for treatment plant, line and hydrant flushing.) 4. Unbilled Unmetered – All uses that are unmetered and no compensation is received (line and

hydrant flushing or any other uses that are authorized but unbilled and unmetered.)

Water Loss – Comprised of apparent loss and real loss. Corrected Input Volume minus Authorized Consumption equals Total Water loss. Apparent Loss – Consists of accounting errors, inaccurate customer meters, illegal connections, and bypassed meters. Because this water was available for sale, these losses are incurred at the retail rate. Real Loss – Consists of all types of leaks, bursts, and storage tank overflows that occur before the customer’s meter. Because this water did not have the opportunity to pass through a customer’s meter, these losses are incurred at the production rate.

Revenue Water – All water consumption that requires revenue collection: Water Exported plus Billed Authorized Consumption. Non-Revenue Water – Water that is not billed and revenue is not received. This is equal to Unbilled Authorized Consumption plus Apparent Losses plus Real Losses. UNDERSTANDING THE METHODOLOGY In accounting terms, an audit is defined as confirming and compiling information gathered on the entity as a whole. The utility is merely verifying that all the data being gathered is the most valid data possible. With this methodology, utility operations are broken down into numerous categories with questions that should verify the data validity. System Input Volume The total water supplied to the infrastructure is the System Input Volume. System Input Volume includes: purchased surface or ground water, the water obtained through interconnects, or water obtained from other sources. Master Meter Accuracy This is the verification or the calibration of master meters to ensure their accuracy. Once the accuracy level has been verified, the percentage of accuracy is documented. Adding this number to the uncorrected meter volume will provide the corrected input volume - the volume that was actually pumped into the distribution system. Corrected Input Volume This is simply the sum of either adding or subtracting the master meter adjustment to input volume. This is all the water that is actually in the distribution system and available to sell.

Depending on how city offices, parks, fountains, line flushing, fire department use and/or other operations are classified, they can be any one of the four types of authorized consumption. Just include them under the correct category for accurate accounting.

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Authorized Consumption This category consists of all water that have been authorized for use or consumption. Authorized consumption includes the following sub-categories:

Revenue Water 1. Billed Metered – Customer accounts whose meters are read and who are billed appropriately

each month. Since this category determines revenue, these meters are most important regarding accuracy. All connections should be metered and on the current billing cycle. A program allowing for all construction/landscaping companies to rent a meter can be implemented, resulting in obtaining revenue for the water and add an additional revenue source.

2. Billed Unmetered – Requires submittal of a form documenting the amount of water used during the month.

3. Water Exported – Water that has been authorized for use by another utility or water provider for which revenue or compensation is received.

Non-Revenue Water

4. Unbilled Metered – This category could contain city/government offices, facilities and uses. Even if city offices are not billed, they should have a meter for determining water use. Irrigation of city parks, fire department use and line flushing should also be included. Fire departments should have a form to track usage that would require documentation of how many times the trucks were filled each month (see Form C). A monthly estimate from the fire department should be more accurate than a utility’s.

5. Unbilled Unmetered – A utility could have all its city/government offices/operations set up under this category. Unmetered line flushing estimations may be entered for this category (see Form D).

It is important to remember that in order to locate leaks or usage, the consumption of each connection should be metered. Water Losses This is the difference between Corrected Input Volume and Authorized Consumption. This consists of two major sub-categories: real losses and apparent losses. Both are considered types of water loss. Real losses are figured at the marginal production cost of water. Apparent loss is figured at the retail rate, because its loss is after the customer meter.

1. Real Losses – These losses are measured from the pressurized point up to the point of measurement of the customer usage. These are physical losses from the infrastructure, mains, valves, service lines and main lines. There are many reasons for leaks: poor installation and workmanship; pressure transients; pressure fluctuations; lack of scheduled maintenance on valves and hydrants; or excessive pressure. All of these contribute to line loss. With proper system management, they can be kept to a minimum.

2. Apparent Losses – These losses occur when potential revenue water is removed from the

system either through theft, meter inaccuracy, or billing procedures that prevent all water from being included in the water loss calculation. All utilities should have a meter replacement program in place.

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WATER AUDIT WORKSHEET

Utility Name: _________________________________________________________________ Type of Utility: (circle one) WSC MUD WCID SUD CITY Other______________ Regional Water Planning Group(s) in which this system operates: ________________________ http://www.twdb.state.tx.us/mapping/maps/pdf/sb1_groups_8x11.pdf Name of person completing this form: ______________________________________________ Phone number of person completing form (with area code) ______________________________ Mailing address of utility: ________________________________________________________ Reporting Period: From ____________________ To____________________________ Percentage of water used: Surface___________ Groundwater________________ Mean household income of population served: ________________________________________ http://factfinder.census.gov/servlet/SAFFPeople? Population served: _______________________________________________________________ Note: unit of measure (acre-foot or million gallons) must stay consistent throughout report 1. SYSTEM INPUT VOLUME MG ACRE-FT OTHER_______________ System Input Volume - Amount of water put into delivery system: ______________ Master Meter Adjustment - Volume master meter did not account for: +/- ______________ Corrected Input Volume - Water delivery plus/minus Master Meter Adjustment: ______________ 2. AUTHORIZED CONSUMPTION Revenue Water Billed Metered - All water sold: ______________ Billed Unmetered - All water sold but not metered: ______________ Non-Revenue Water Unbilled metered - City and local government use, metered line flushing: ______________ Unbilled unmetered - Line flushing/fire dept use: (estimate) ______________ Authorized Consumption - The total of all Authorized water: ______________

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3. WATER LOSS Apparent Loss Customer Meter Under-Registering – Inaccurate customer meters +/- _______________ Billing Adjustment/Waivers _______________ Unauthorized consumption (theft or estimate) _______________ Total of Apparent Loss _______________ Real Loss Storage tank overflows (estimate) _______________ Main break/leaks: (estimate) _______________ Customer service line leaks/breaks: (estimate) _______________ Total of Real Loss _______________ Total Water Loss = Apparent Loss + Real Loss _______________ 4. TECHNICAL PERFORMANCE INDICATORS Performance Indicators for Real Loss Number of service connections ______________ Number of miles of main lines ______________ Service connections divided by miles of main ______________ Total Real Loss/Miles of Main/365 ______________ Total Real Loss/No. of Service Connections/365 ______________ 5. FINANCIAL PERFORMANCE INDICATORS Total Real Loss ______________ Production cost of water ______________ Total Real Loss multiplied by production cost of water: ______________ (Example from instruction sheet) Real Loss x $2.50/1000 Total Apparent Loss ______________ Retail cost of water ______________ Total Apparent Loss multiplied by retail cost of water: ______________ (Example from instruction sheet) Apparent Loss x $4.25/1000

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WATER AUDIT WORKSHEET INSTRUCTIONS

This instruction guide is designed to aid in completing the Water Audit Reporting Form and submitting the most accurate data available. This information will aid in determining which operational areas may need assistance. A few general notes on the first section:

• List the Regional Water Planning Group in which the utility is located. This information may be determined by using the website listed on the reporting form.

• Remember that the type(s) of source water used must total 100%. • Use the web address on the reporting form to locate the mean income of population served.

The data may be obtained by metropolitan area, county, and/or zip code. • Estimate the population the utility serves (this is not the number of service connections). • Note the reporting period. Either a calendar or fiscal year may be used. • Use consistent units in reporting the data, either million gallons or acre-feet. 1. System Input Volume

a. Water Delivery – Includes all water pumped, produced, or obtained through interconnects and purchased water. This is the sum of all master or source meters for the year. Example:

Water Delivery is 8,983,674 gallons b. Master Meter Accuracy - Is achieved by calibrating the master or source meters

to determine the accuracy level expressed as a percentage. Example:

Water Meter Accuracy is 96%. c. Corrected Input Volume- Is obtained by dividing the Water Delivery by Water

Meter Accuracy and multiplying by 100. Example:

8,983,674 ÷ .96 = 9,357,993 d. Master meter adjustment - Is obtained by subtracting Water Delivery from the

Corrected input volume. Example:

9,357,993 – 8,983,674 = 374,319 Note: If meters are over registering, divide Water Delivery by 1.03, if the meters are 103 percent accurate and subtract the adjustment due to the over registering of the meter. The master meters have registered more water than the actual pumped amount.

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2. Authorized Consumption a. Billed Metered – All water sold that has been metered. b. Billed Unmetered – All water sold but not metered; can be an estimate. c. Unbilled Metered – Unbilled water but is metered. Enter all metered flushing

here. d. Unbilled Unmetered – Unbilled water that is not metered. Enter all unmetered

flushing here. Note: Authorized Water Usage may be subtracted from the Corrected Input Volume to obtain

Total Water Loss for the year.

Corrected Input Volume - Authorized Water Usage = Total Water Loss

3. Water Loss A. Apparent Loss

a. Customer Meter Under Registering –If customer meters are 98% accurate, that means the meters are 2% under registering. Simply divide the Total Water Sold by accuracy level of meters.

Example: Total Water Sold that has been metered = 7,125,000 million gallons

7,125,000 ÷ .98 = 7,270,408 gallons 7,270,408 – 7,125,000 = 145,408, gallons not recorded by meter.

Note: If meters are over registering by 4 % then divide Water Delivery by 1.04 and then subtract that amount.

b. Billing Adjustments/Waivers – Amount of water that was waived during the audit

year. Example:

If the utility waived 28,000 gallons due to leaks on the customer’s side during the year, 28,000 would be entered.

c. Unauthorized Consumption – Estimate amount of water lost due to theft.

Example: If a customer moved into a new home and began to use water without authorization.

B. Real Loss

a. Tank Overflows - Amount of water lost due to storage overflows. b. Main Leaks/Breaks – Amount of water lost through main leaks and breaks. c. Customer Service line Leaks – Amount of water lost through service line leaks.

Real Loss estimates should be as accurate as possible.

Note: The sum of Total Water Loss and Authorized Consumption equals Corrected Input Volume.

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4. Technical Performance Indicators Performance Indicators are quantitative measures of key aspects within the utility. With the use of these indicators, each utility will have a history to track performance. The first formula is Total Real Loss/Miles of Main/Day.

1. Use the Total Real Loss number from the reporting form, then divide by 2. Miles of Main lines, then divide by 3. 365 (days in a year) 4. Record this number where indicated.

The second formula is Total Real Loss/No. of Service Connections/Day

1. Use the Total Real Loss number from the reporting form, divide by 2. Number of Service connections, divide by 3. 365 (days in a year) 4. Record this number where indicated.

5. Financial Performance Indicators

1. Value of Current Real Loss

Example Total of Real Loss = 1,625,394 gallons $2.50/1000 = production cost 1,625,394 x $2.50/1000= $4,063.50 $4,063.50 (Value of Real Loss /year)

2. Value of Current Apparent Loss Example Total of Current Loss = 189,408 gallons $4.25/1000 = retail rate 189,408 x 4.25/1000= $805.00 $805.00 (Value of Current Apparent Loss/year)

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WATER BALANCE Below is an example of a water balance with the terms as presented in this manual.

• Authorized Consumption and Water Loss equal Water Exported and Water Supplied • Billed Authorized Consumption equals Revenue Water equals Billed Exported Water, Billed

Metered Consumption and Billed Unmetered Consumption. • Apparent Losses and Real Loss equal Water Loss. • Unbilled Authorized Consumption, Apparent Loss and Real Loss equal Non-Revenue Water.

Water Billed Water

Exported Billed

Exported

Own sources

Authorized Authorized Revenue

Consumption Consumption Water Billed Metered Input Water Billed Unmetered Volume Supplied Unbilled

Authorized Unbilled Metered

Consumption Non Unbilled Unmetered Apparent Revenue Unauthorized

Consumption Purchased Water Loss Water Customer Meter

Inaccuracies Water Loss Real

Leakage on Mains

Loss Leakage and Overflows/Storage

Leakage on Service lines

PERCENTAGES vs. VOLUME OF WATER How well is the utility managing their water? Currently, the industry uses a method to determine water loss by using a percentage based on water sold to water billed that is unable to show where in the system the loss is occurring and/or how much the loss cost the utility for the year. Under this percentage method of water loss, the utility is guessing where to spend time and money, almost trying to diminish their water loss by trial and error. Percentages do not associate a volume or a cost to the lost amount, nor do they aid the utility in determining where to focus their resources. Without associating a cost or method to determine where the loss is coming from, the utility cannot expect to effectively diminish cost while conserving a natural resource that is vital to life. In the past, water loss was only one category. That practice prohibited the utility from pinpointing loss. Now water loss has two subcategories, apparent loss and real loss. They associate volumes of water with

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either a retail cost or production cost which enable the utility to focus available resources where they are most effective. If apparent loss is the main source of loss, then focused efforts should be on minimizing theft, reviewing accounting methods, and implementing meter testing and replacement programs. If real loss is the main source of loss, then implementation of leak detection programs and a thorough review of the distribution system should occur.

WATER LOSS AUDIT PROGRAM After conducting a top down water audit the utility must develop procedures needed to increase overall efficiency of the utility, and explain how each category fits into the overall understanding of a water loss program. When the utility considers water loss to be high, the first step is to develop a systematic plan that reduces the volume of loss to an acceptable level. As with any business, both short term and long term plans need to be achievable. Estimated costs should be developed and included for each plan. IMPORTANCE OF METERS All meters within a system are important because they record water flow and provide data that determines water loss and revenue. Some utilities may elect not to meter certain connections. Whether they are city offices or commercial properties, it is impossible to accurately determine water loss volume when there is not a meter on that particular connection to verify volume of use. Not only is the utility unsure of the volume of water used by that customer, but they are also unsure if any water loss is occurring between the point of connection with the utility’s pipe and the customer’s pipe, thereby creating more inaccurate data. Master Meters Correct installation of production meters is important to maintain accuracy. Most manufacturers recommend that meters be installed on only straight runs of pipe. A total of at least ten and preferably fifteen pipe diameters of straight pipe should be in front (upstream side) of the meter, and there should be ten diameters on the downstream side of the meter. Correctly interpreted, this would mean that 4 inch pipe would need 10 times that number of straight pipe. Meter companies have charts that list accuracy limits for each size and type of meter. For meters with high gallons per minute flows, it is even more critical that they maintain high accuracy. Due to the volume of water passing through these meters, it is recommended that meters 2 inches and larger be calibrated every year. Meter testing, calibration and replacement programs are strongly recommended. Utilities not calibrating master meters for Master Meter Adjustment may be putting water into the distribution system that otherwise would be considered loss.

For example: The utility reads all source meters for the entire year and sums them to get a System Input volume of 1,000,000 gallons, but as the utility combines Authorized Consumption with Total Water Loss, the sum is only 900,000. Therefore, they believe that they are 100,000 gallons off on some of their estimations, when in actuality they are off by 200,000 gallons, because of the master meter is under registering by 100,000. Remember that Authorized Consumption plus Total Water Loss must equal Corrected Input Volume, not System Input. After determining meter accuracy by calibrating or verifying the flow to the master meters, the utility would either add or subtract the number of gallons to the System Input, depending on whether they are under or over-registering. The addition or subtraction of Master Meter Adjustment to System Input will achieve Corrected Input Volume. It is so important to eliminate all possible inaccuracies within the utility. The calibration can be conducted at the end of the utility’s business cycle each year, corresponding with the year-end audit. The timing of this procedure would also ensure that the meters are accurate for the beginning of the new business cycle.

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Correct meter application is as important as meter accuracy. Meters are sometimes installed according to the pipe size in the ground without considering whether the meter size matches the demand. This example could be applied for a residence on a large tract that is being irrigated by a sprinkler system.

A 2 inch turbine meter will read water moving from 2 to175 gpm. If the use is 160 gpm for 2 hours per day, but the majority of its use it is only reading 5 to10 gpm, then this particular meter is being used too close to its design limits. Because compound meters have two meters side-by-side and are designed to read low flows and high flows, they would be more effective in this example. Small residential 5/8 x 3/4 meters should be installed with either a 5/8 or 3/4 line. The same rules apply to large meters; a 4 inch meter should be installed on a 4 inch pipe. If the 4 inch meter is installed on a smaller pipe, then the water flow and pressure has changed and this application will cause the water to be recorded inaccurately. Look at the entire system to ensure meter installations are correct for each application. Installation of accurate metering will save significant revenue and is worth the time invested. Meters should be able to accurately record the full range of expected flow rates.

Residential Meters Residential meters, record management and theft are the three sub-categories that make-up the category of Apparent Loss. Apparent Loss is a volume of water that is associated with the utility’s retail rate, because a utility would have received compensation for the water had it been recorded. Meters are cash registers, and it is in the best interest of the utility to implement programs that are designed to maximize the efficiency of these meters. Depending on water chemistry and customer use patterns, residential meters may need to be replaced when they “roll over” or when they reach 8 to 10 years old. Accounting software can be purchased that will notify staff when meter limits are reached. Meter replacement programs can be implemented by reviewing each meter’s age throughout the utility, replacing the oldest first. Last in, first out (LIFO), is a marketing term that can be used with these programs. Once these programs are implemented, it may take time to see revenue increases and/or water loss volumes diminish. Proper meter selection begins with knowing the authorized water use of each end user. Large subdivision builders will often hire subcontractors to install meters and the final inspection is then conducted by the managing utility. However, after the homeowner occupies the residence, the initial meter application may change. The homeowner may install irrigation systems that exceed the limits of the current 5/8 meter. This new application now causes the meter to inaccurately register an unknown percentage of water. The majority of residential meters will read predominantly in the customer’s favor, which can result in lost revenue for the utility. The utility needs to know the operating limits of each type of meter being used within the system so that the correct meter can be installed for each application. The cost to initiate and maintain a meter replacement program can be outweighed by the benefits of initiating such a program. The accuracy level of any customer meter is just as important as that of the master meters. Water chemistry along with age can affect the accuracy of meters. Under normal operating conditions, residential disc meters are calibrated to read from 1/4 of a gallon to 20 gpm, with a continuous flow of 8-10 gpm. Different brands of meters may have different life expectancy. Inaccurate customer meter problems are twofold, the total volume of apparent loss will be inaccurate and lead to more estimates in the total water loss equation; as a result, utilities will not receive the compensation otherwise due to them. After implementation of a meter replacement program, the utility may see an increase in phone calls requests for meter verification, as users may report that; “it’s impossible that I used that much water.” The utility may have to explain that the volume of water consumed may not have increased, but the water is now more accurately accounted for due to the meter replacement program. Accounting for all water should be the number one priority for the utility. Implementation of meter replacement programs will not only show a decrease in apparent loss, but, an increase in revenue.

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Record Management and Billing This is the second sub-category within Apparent Loss. The information obtained from a utility’s meter and billing system is vital to many parts of its operation. Peak summer demand, changes in water use patterns, rate design, design information, and system stability all depend on accurate and current records. Good data management, including metered uses and billing records, provide record of the utility’s past performance and future potential revenue. Accounting errors can present challenges for the utility. Examples of these challenges include: non-billing or accounting of every connection; data incorrectly transferred on meter readings; and customer water usage data being altered during the billing cycle. A prime example is when the utility changes the amount billed or waives a portion of the water used due to a leak or some reason. Where within the billing records did the unbilled water go? Even though the billing department chose to waive the volume of water for customer satisfaction, follow the volume through the billing program to ensure that it does not become a real loss or the volume is not lost altogether. It is considered an apparent loss because the meter did record the volume of water. Another administrative practice is to verify that the retail “tier structure” is billed correctly and generating the appropriate revenue. This can be done by reviewing a percentage of bills and calculating the usage by the individual revenue tiers to ensure the billing program is calculating the consumption to the right revenue tier. A utility may want to verify this with several bills having different amounts of water consumption so that the utility can have a high confidence level with the billing software. Theft of Service This is the third sub-category of Apparent Loss. It is considered Apparent Loss because it was in the distribution system ready to sell. However, it was taken before the water had an opportunity to go through a meter and generate revenue. Theft of water can occur by construction companies tapping into fire hydrants, and/or unauthorized connections by residential customers. One method for theft is for the utility to install a meter on a given hydrant and to have the water truck circumvent the system by hooking up to the hydrant side that does not have a meter on it. Some utilities have begun to charge a rental fee for supplying meters that would cover the rental cost plus the cost of selling the water. The price needs to be set high enough to pay for an estimated amount but not too high to consider taking water from the other side. Rental agreements can offset costs of others taking water without proper authorization. A utility can also create a program that entails labeling all fire hydrants and working with local law enforcement officials to notify them of unauthorized activity on fire hydrants. Some utilities attach a sign to the hydrant that states, “Unauthorized users will be prosecuted.” Illegal taps are more likely to occur where a customer may be able to install a separate tap to irrigate a lawn or water livestock without being seen by neighbors. In order to eliminate theft when an account is closed, the utility could choose to remove the meter instead of turning the valve off or locking the valve closed. Meters, record management and theft of service are all part of Apparent Loss. They all consist of accurate measurement of a loss and recorded so that the utility would have received compensation. Since the loss of this water occurred at or after the customers meter it will have a retail cost associated to it. Main Line Leaks, Service Line Leaks and Storage Tank Overflows These are sub-categories within Real Loss and because the water did not go through a customer meter, the lost volume is associated with a production cost. Except for storage tank overflows, these sub categories are generally expensive and time consuming due to the difficulty in locating and repairing the leaks. They are considered real loss, because, as previously discussed, real loss is all the water that went through the master/source meters but has not gone through a customer’s meter. Since this is “produced” water, it is calculated at a production rate. In order to more accurately track hydrant flushing, the utility could implement the use of a diffuser with a pressure gauge that measure flow by pressure.

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When development occurs and the utility takes on more connections, the number of service line leaks also increase. A study done in Great Britain concluded that systems having more than 32 connections per mile had the majority of their leaks on the service lines and utilities with less than 32 connections per mile had the majority of their leaks on the main lines. This study occurred on systems that fully implemented this water loss methodology. METHODS TO LOCATE AND MINIMIZE WATER LOSS This section shows how a utility can utilize several water loss techniques to locate loss within the system and conduct a bottom up audit. As discussed earlier, this type of audit is verifying that the data used is the most accurate and current possible. Bottom up audits are the next step for utilities wanting to achieve a higher level of efficiency. They highlight issues within the utility that are preventing the utility from effective loss control. In performing the audit, billing procedures, maintenance costs and productivity levels can be reviewed. With time, financial rewards will be realized, along with substantiated water savings, essentially eliminating the need to look for more water. System Investigation System investigation requires extensive knowledge of the utility’s infrastructure; therefore appropriate staff should be chosen to conduct this study. Items that should be studied include, but are not limited to:

1. Types of storage tanks and stand pipes. 2. Is there an interconnect with another utility? Make sure they have properly installed check

valves. 3. Is the utility aware of the location of all valves? 4. Does the same booster pump come on first every time? Equipment longevity can be extended

if a different pump starts each time. 5. Is the utility implementing the use of forms for the fire department (Form C), line flushing

form (Form D) and the leak repair summary report (Form E)? 6. What type of pipe is in the ground (i.e. PVC or iron)? Note the size of each. This information

can be applied to the pin maps. 7. Are all meters the right size for each particular connection? 8. Residential meters should be 5/8 x 3/4 inch or similar. Are they installed correctly? 9. If they are close to reaching their operational limits, has their flow accuracy been tested? 10. Does the entire field staff know the system thoroughly?

Meters should have check valves and/or backflow prevention devices. These will prevent household water from re-entering the utility’s main lines. Meters allow water to flow in the opposite direction. Due to pressure differences between the outside plumbing and inside plumbing, lawn and garden chemicals from a hose-end sprayer could enter the house plumbing if anti-siphon devices are not used on the outside faucets. After this particular study, the utility should create a Utility Operations Manual that includes all the above information. The operations manual can be used by all staff during emergencies and when key personnel are out of the office for extended absences. Once the utility has done all the steps suggested here, the creation of pin maps will be the next step in minimizing water loss. Pin Maps Pin maps show the entire infrastructure from the meters and valves to all service and main lines. Pin maps can be created using Geographic Information System (GIS), or by an engineer. By using GIS, the map may be periodically updated with relatively small cost. The map should be large enough to show the entire system, so that all staff members can refer to it at any time. Historically, they were referred to as pin maps because of the color of pin that is placed on the map. For example, red indicated service line leaks, blue for main leaks and other colors for each scenario that may arise. Each task should be represented by its own color. It is imperative that the map be updated frequently. Even if the utility has this map electronically, it is important that all leaks and repairs to the infrastructure are updated. Pin maps are an important asset to

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the utility and may aid in justification for replacing sections of old, leaking pipe. Having a map with clusters of pins appearing on a particular section can indicate the need to replace the section rather than repair it with another clamp. The map may be used as a visual aid to justify expenses to the board of directors. Distribution Controls These are factors controlling the overall distribution system. Is Supervisory Control and Data Acquisition (SCADA) installed on the system? SCADA systems can be used to manage many aspects in the utility’s day-to-day operations. They also maintain pumping and pressure controls and will even monitor storage tanks. They can be programmed to control many operations that can give staff more time for other projects, alleviating the need to hire additional staff. Water Leak Survey These surveys are part of the leak detection program. Have a staff meeting on water loss with all field personnel and gather input while prioritizing their ideas and/or locations of water loss in the order of importance. If the utility does not already use a form for the estimation of these leaks, use Form E for a template. Note all points of water loss on the pin maps, and refer to the map when fieldwork begins. Develop a water loss program. Don’t rely on customers to report leaks. Make an effort to discover the leaks before they cost the utility more money. Leak Detection and Repair To be effective, leak detection and repair should be a continuous program. Even as recordkeeping is improved and meters are being installed, tested and replaced, the utility should be aggressively involved in leak detection and line repairs. Form A, the LEAK DETECTION AND REPAIR WORKSHEET, is a useful document to aid in maintaining a successful leak detection program. In addition to saving the water lost through leakage, a leak detection program can pay for itself in reduced water production costs, reduced future repair costs and deferred plant expansion, except when the water loss from the system is very low. As each leak is being repaired, the repair crew can implement Form B, the LEAK DETECTION SURVEY DAILY LOG, to aid in prioritizing leaks. Studies have generally shown that the life of a leak often depends on the type of subsoil. In areas with sandy soil or limestone strata, water from a leak may not surface near its source or may not surface at all. Clay soil is considered impermeable and will normally keep water from going deeper and into the next lower strata, but this may not always be the case An ongoing leak detection program is essential. Leak detection methods include using a variety of flow measurement devices. Sonic and acoustic devices are used to detect leak sounds in mains or service lines. Acoustical leak detectors consist of headphones and a ground microphone. They are practical, inexpensive and easy to use. Referred to as leak finders, they will find the leak within a range of several feet. As with most acoustical equipment, an estimate of the leak location is needed. This type of listening device tends to be lightweight and easier to use than others types of leak detectors. As the utility implements a leak detection program the first leaks located will be the larger ones. The process should be repeated in order to locate the smaller leaks that were not heard due to the background noise of the larger leaks.

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Correlators Correlators are known in the industry as leak pin pointers, as they are able to locate a leak within several inches. This accuracy enables a utility to save money by only removing a small section of pavement. Correlators use two transmitters to locate leaks. Once programmed with the correct parameters. The correlators will transmit information to the logger, which indicates the leak location. Some utilities use acoustical detectors to find the leak, and then employ correlators to pinpoint it within inches. They will only be as accurate as the information programmed into the device. One method used by large municipalities to offset the expense of correlators, is to purchase them and then subcontract out to smaller systems. Meter Testing Due to rising labor costs, efficiency matters concerning testing experience, and quality control issues, many utilities now pay outside testing firms to conduct all their tests. TWDB has ultrasonic flow meter verification equipment available for free 30-day loans. This equipment is used to verify flow from source/master meters and determines the need for meter calibration. Residential meters can be tested while they are still “in-line.” Obtain a new meter and attach meter spuds or tails that allow it to be connected to a garden hose. To verify flow, lay the garden hose meter next to the “in-line” meter and turn the faucet on and watch both meters simultaneously. If the in-line meter is inaccurate, make note of the difference and then go to the next house and repeat this procedure. If testing all meters is not possible, a 5-10 percent sample test can represent the entire system. Some meter companies also sell portable testing equipment that can be used in the field. While testing the meter, ensure that it is not only installed correctly but that it is the correct meter for the application. Meter size is also an important aspect of meter accuracy. Verify that each meter size is appropriate to the size of the service line so that a residential 5/8 x 3/4 inch meter is not installed on a 1 or 1.5 inch line. Apply the same principle to a 4 inch meter so that they are not installed on pipe larger or smaller than the meter. If the water pressure increases as water flows into the meter or is constricted thus increasing the flow rate of water, then the installed meter has inaccuracy potential. Distinct Management Area (DMA) Distinct Management Area (DMA) is a proven method implemented by closing valves and isolating sections of the system during nighttime hours. This method is conducted by isolating a section of pipe, installing a meter at the entry valve and then closing the valve on the end of the section. By doing so, the only way for water to escape is through the customer’s meters. In the morning, read the large meter at the valve to see if significant volumes of water registered. For the test to be most effective, it should be done at night to eliminate large water usage or at least minimize the use. Reading the meter at different times will determine leaks on that section and the volume of water lost. Conducting this procedure throughout the system will help prioritize starting points for the leak detection program. Although leaks that never come to the surface are more difficult to find, they can be located. Leakage rates may also be estimated by using Table 1. Residences generally have a low consumption rate at night. To ensure accuracy, notify each affected customer by placing flyers on their door so that water use may be kept to a minimum. Utilities should also monitor pumping stations at night to see if the pumps are staying on longer than normal, another possible leak indication. Monitor the booster pumps, as a loss of pressure is another indication of water loss. Determine if the pressure loss is for one day, or if it has been consistent for several days or weeks.

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Pressure Management Excessive pressure exerted on the infrastructure can maximize wear and increase water consumption on the system as a whole. Pressure Management implementation will;

• Reduce wear and tear on booster pumps and pressure relief valves (PRV) • Lessen pressure exerted on infrastructure • Lessen pressure on meters and customer’s plumbing • Reduce water consumption at customer side • Reduce water loss through leaks in the system when lower pressure is used.

The volume of water being forced out of a leak at 100 psi is greater than at 65 psi. Higher pressures also exert more wear on a system, thereby conserving water when evenly lowering the pressure throughout the system. PERFORMANCE INDICATORS (PI) These are indicators that measure utility efficiency in a particular area of operation, whether the utility is measuring performance of employees, line loss or pumping station capacity. There are PIs for every aspect of the operation. Not only will indicators show how efficient the utility is today, but they also establish a history or benchmark that can be used for comparison next year or next month. PIs are designed to assist the utility in achieving a higher degree of efficiency. PI’s are designed so that different aspects are divided into each other to establish benchmarks. Below are two examples:

Total Real Loss/Miles of Main/Day

1. Use the Total Real Loss number from the reporting form, then divide by 2. Miles of Main lines, then divide by 3. 365 (days in a year)

Total Real Loss/No. of Service Connections/Day

1. Use the Total Real Loss number from the reporting form, divide by 2. Number of Service connections, divide by 3. 365 (days in a year)

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CONCLUSION Water loss is not “rocket science” however; the utility should carefully examine that one really needs to ponder every aspect of a utility to identify the main areas of water loss. When the utility begins to implement water audits into their business plan, they can expect to become more efficient by focusing on problem areas that were identified by the top down audit. With water availability decreasing and rising water treatment costs, this type of audit will become more widely used. As utilities become more aware of the issues that affect water loss, they will be able to address and diminish water loss. Audits are designed to guide the utility to the appropriate category of water loss so that the utility can focus its resources on specific areas of water loss, thereby utilizing its resources effectively. By minimizing water loss the utility will effectively diminish its need to locate additional water sources. It should be noted that real loss represents a wasted resource as the utility has spent financial resources on the production of this water. Minimizing water loss may minimize the search for future water resources to meet demand. By using this methodology, along with the implementation of audits in the utility’s operations; the utility should have an incremental drop in water loss each year. As with any business plan, it will take several years for utilities to begin to see the effects of implementing this procedure. Therefore, goals should be long term but certainly achievable.

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RESOURCES Julian Thornton, WATER LOSS CONTROL MANUAL. McGraw-Hill Helena Alegre, Wolfram Hirnir, PERFORMANCE INDICATORS FOR WATER SUPPLY SERVICES. IWA Publishing. Andrew Chastain-Howley is a Water Loss Control Specialist with Water Prospecting and Resource Consulting (WPRC) based in Fort Worth, Texas. WPRC is an international water resource consultancy with worldwide experience in the assessment, management and reduction of water system losses. Julian Thornton is an international water loss specialist with 25 years experience and author of “The Water loss Control Manual” by McGraw Hill. He is a Team Leader for International Water Association (IWA) and is the past Vice Chair for American Water Works Association (AWWA) Water Loss Control Committee. Mr. Thornton is currently chairing the AWWA M36 rewrite committee and is actively working on several AWWA Research Foundation water loss control projects. George Kunkel P.E. has worked for the Philadelphia Water Department for nearly 25 years and has chaired the city’s Water Accountability Committee for over ten years, overseeing efforts that have resulted in a reduction of over one-third of the city’s non-revenue water. Additionally, he has chaired the Water Loss Control Committee of the AWWA and has been actively involved with a number of other water loss projects sponsored by AWWA and the AWWA Research Foundation.

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Form A

LEAK DETECTION AND REPAIR PLAN WORKSHEET

Utility Name: _____________________________________Date:________________________ A. AREA TO BE SURVEYED

1. The area in the distribution system to be surveyed should be mapped using the results of the water audit. Higher priority should be given to areas with high leak potential. (Items to consider include records of previous leaks, type of pipe, age of pipe, soil conditions, pressures, ground settlement and installation procedures.)

2. Estimate the total miles of main to be surveyed (excluding service lines). 3. Estimate the average number of miles of main to be surveyed per day. 4. Describe the equipment and procedures that will be used to detect leaks. 5. Estimate the number of working days needed to complete the survey.

B. PROCEDURES AND EQUIPMENT

1. Experience has shown that the best results have been obtained by listening for leaks at all system contact points such as water meters, valves, hydrants and blow-offs.

2. The average two-person survey crew can survey about two miles of main per day if

the main is located in a city or subdivision and all valves, hydrants and meters are checked.

3. Items to consider include distances between services, traffic and conditions and

total number of listening points. 4. If not to listening for leaks at all available listening points, what plans will be made

for checking missed points later? A portable listening device, field notebook, hammer, screwdriver, flashlight and cover key are essential items. The leak surveyor should note broken valves, hydrants, meters or other unserviceable equipment in addition to location, size and type of leak or other water loss condition observed.

5. Describe how the leak detection team and the leak repair crew will work together.

A leak is normally reported by a citizen or utility employee who sees the water leaking out of the ground or building. The leak detection team should be called in first or at the same time as the repair crew to pinpoint the leak. In other cases, the leak detection crew might discover a leak, pinpoint it and initiate the work order.

6. What measures will be used to minimize the chance of digging “dry holes”?

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7. Describe the methods that will be used to determine the flow rates for excavated leaks. Formulas for calculating approximate flow rates for typical leaks are presented in Figure 1.

C. LEAK DETECTION SURVEY BUDGET Number of

days $/day Cost

Utility Crew Cost

Consultant Crew Cost

Vehicle Cost

Cost of Leak Detection Equipment

Supervision and Administration

Other Costs

Total Estimated Costs

D. LEAK SURVEY AND REPAIR SCHEDULE Indicate realistic, practical dates. Start Dates Completion Dates

Phase 1

Area 1 Area 1

Area 2 Area 2

Area 3 Area 3

Phase 2

Area 1 Area 1

Area 2 Area 2

Area 3 Area 3

Prepared by ____________________________ Date _____/_____/_____ Title ______________________________________________________

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Form B LEAK DETECTION SURVEY DAILY LOG

Date:______________ Crew:_____________________ Survey Time:_____________________ Area:___________________________ Vehicle:______________________________________ Weather:_____________________________________________________________________ Starting Address:_________________Ending Address: ________________________________ Route:_______________________________________________________________________ Miles Surveyed:_______________________________________________________________ Brief Description of Each Leak Discovered / Suspected (Size and Location):

1)

2)

3)

4)

5)

6)

Notes:

Signed (Crew Chief):

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Form C

WATER FOR FIRE FIGHTING AND TRAINING

FIRE DEPARTMENT NAME: CITY OR SYSTEM NAME: MONTH: TANK SIZE: (gal) 1 16 2 17 3 18 4 19 5 20 6 21 7 22 8 23 9 24 10 25 11 26 12 27 13 28 14 29 15 30 31

MONTHLY TOTAL:

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Form D LINE FLUSHING REPORT

Date Location GPM Time Gallons

X

X

X

X

X

X

X

X

X

X

X

X

Total Gallons

Remarks:

Signature:

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Form E LEAK REPAIR SUMMARY REPORT

By: Date:

Work Order #: Crew: Date Completed:

Area/Location:

Found per Leak Detection Survey (Attached)?

LEAK TYPE PIPE MATERIAL

Meter Leak Fire Hydrant Galvanized Iron A.C.P. Meter Spud Meter Yoke Black Iron Steel Valve Joint Ductile Iron PVC Curb Stop Main Cast Iron Copper Service Other Polybutylene Transite

OTHER INFORMATION

Depth to top of pipe __________(ft) Type of bedding _________ Type of backfill __________ Leakage Rate _________(gpm) (___Measured ____Estimated) Estimated age of leak ________ Estimated water lost __________(gal) Previous repairs? _______________________________ How was leak repaired (previous/this time)?_________________________________________ _______________________________________________(Attach “Before” and “After” Photos) Shape and dimensions __________________ Original wall thickness of pipe ___________(in) System Pressure Measured ____________? Corrosion ______? Outside _____ Inside ________

COST OF REPAIRS Labor Costs: Total hours worked ___________ x Average hourly rate $ ______________ = $_____________ Equipment Cost: Equipment Used Hours Used X Cost of Equipment = Total Equipment Cost 1) X $ = $ 2) X $ = $ 3) X $ = $ 4) X $ = $ Material used Cost $ Administrative/Supervisory/Other Cost $

Total Cost of Repairs $ Follow-up listing test? (date) OK? Supervisor’s Signature

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Table No. 1 Leak Rates from Holes of Known Size

Gallons per Minute (gpm) Area of Leak Pressure Pounds per Square Inch (psi) Square Inches 10 20 40 60 80 100

0.005 0.5 0.8 1.1 1.3 1.5 1.7 0.010 1.1 1.5 2.2 2.6 3.1 3.4 0.025 2.7 3.8 5.4 6.6 7.6 8.5 0.050 5.4 7.6 11 13 15 17 0.075 8.1 11 16 20 23 26 0.100 11 15 22 26 31 34 0.200 22 31 43 53 61 68 0.300 32 46 65 79 92 102 0.400 43 61 86 106 122 136 0.500 54 76 108 132 153 171 0.600 65 92 129 159 183 205 0.700 76 107 151 185 214 239 0.800 86 122 173 211 244 273 0.900 97 137 194 238 275 307 1.000 108 153 216 264 305 341 1.100 119 168 237 291 336 375 1.200 129 183 259 317 366 409 1.300 140 198 280 343 397 443 1.400 151 214 302 370 427 478 1.500 162 229 324 396 458 512 1.600 173 244 345 423 488 546 1.700 183 259 367 449 519 580 1.800 194 275 388 476 549 614 1.900 205 290 410 502 580 648 2.000 216 305 431 528 610 682 2.500 270 381 539 661 763 853 3.000 324 458 647 793 915 1,023 4.000 431 610 863 1,057 1,220 1,364

The above table is based on the following formula: Flow = 2.8 x Area x Square Root of (148 x Pressure) Flow – gpm, Area – Square Inches, Pressure – psi Example use of TABLE 1. A hole 1/8 inch by 1 ¼ inch in size at 50 psi First calculate the area: 1/8 inch = 0.125 inches, 1 ¼ inch = 1.25 inches, Area = 0.125 x 1.25 = 0.156 square inc From the table, the size that is closest is 0.1 and 0.2 square inches, and the pressure is between 40 and 60 psi. The flow rate is going to be about 36 gpm.

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TEXAS WATER DEVELOPMENT BOARD’S BROCHURES, LEAK DETECTION EQUIPMENT

AND SERVICES HANDOUT

The Texas Water Development Board is a non-regulatory state agency that is set out to provide many services to Water Utilities around the state. Several of these services are: providing brochures, conducting Water Audit/Leak Detector Workshops, and loaning Leak Detectors and master meter verification equipment free for 30-days. The brochures we provide range in numerous topics including lawn watering, information about your utility, water wise plants. Most of these are also available in Spanish. A complete list of brochures can be found on our website, http://www.twdb.state.tx.us/assistance/conservation/pubs.asp. We are able to send up to 500 brochures per year at no charge, to water utilities, river authorities and other types of governmental agencies. Water Audit/Leak Detector Workshops are available anytime of the year. This is a TCEQ approved workshop which entitles each operator 4 hours of credit towards the renewal of their operator’s license. This workshop discusses how a system can achieve maximum efficiency by implementing a leak detection program and conducting a comprehensive water audit. The Texas Water Development Board presenter will travel to your system and conduct the workshop; all training materials necessary will be provided. The sponsoring system is responsible for providing a training room and scheduling with other systems to ensure a class size of no less than 10 attendees to be eligible for this workshop. An agenda for the workshop and other relevant information is available by contacting Mark Mathis, 512.463.0987 or by accessing our website, http://www.twdb.state.tx.us/assistance/conservation/Municipal/Water_Audit/Leak_Detection/LeakDetection_Workshop.asp. Our free equipment, an Aquascope and Panametrics are both available for loan for 30-days. The Aquascope is an acoustical sounding device that will help you determine where your leaks are within your system. The device has headphones and a ground microphone; together they work quite well in pinpointing your leaks and ruptured pipes. The Panametrics (an ultrasonic device) works with transducers that are placed onto the pipe near your master meter. This equipment will verify the flow rates going through your master or source meters. Once again, all of this information is provided to you without cost to your utility. To implement one or all of these services, call Mark Mathis at 512.463.0987 or access our website at www.twdb.state.tx.us/assistance/conservation/consindex.asp.