ryeleak detection931-289-2300
A PRACTICAL APPROACH TO WATER AUDITS AND
LEAK DETECTIONPresented By:
RRYE ENGINEERING PLCConsulting Engineers & System Operators
Friday, March 15, 2013
RYE ENGINEERING PLCConsulting Engineers & System Operators
4210 West Main StreetErin, TN 37061
Phone: (931) 289-2300Fax (931) 289-2313
Leak Detection Services
Experience and QualificationsMike Sheppard, Senior
Project Manager
• Water Distribution Manager CGW (Retired)
• 35+ Years of Experience
• Utility and Construction Background
Why is Leak Detection Important?
TN Comptroller’s Office
• After January 1, 2013
• All Water Audits in AWWA Format
• Reduce “REAL LOSSES”
AWWA Water BalanceBilled Metered Consumption(including water exported)
Billed Unmetered Consumption
Unbilled Metered Consumption
Unbilled Unmetered Consumption
Unauthorized Consumption
Customer Metering Inaccuracies
Systematic Data Handling Errors
Leakage on Transmission and Distribution Mains
Leakage and Overflows at Utility's Storage Tanks
Leakage on Service Connections up to point of
Customer metering
Figure 1. IWA/AWWA Water Balance (All data in volume for the period of reference, typically one year)
System Input Volume (corrected for known errors)
Authorized Consumption
Billed Authorized Consumption
Revenue Water
Unbilled Authorized
Consumption
Non-Revenue Water (NRW)
Water Losses
Apparent Losses
Real Losses
Real LossesUnauthorized Consumption
Customer Metering Inaccuracies
Systematic Data Handling Errors
Leakage on Transmission and Distribution Mains
Leakage and Overflows at Utility's Storage Tanks
Leakage on Service Connections up to point of
Customer metering
Water Losses
Apparent Losses
Real Losses
Real Losses Water Main Leakage Service Line Leakage
Apparent Losses Encountered
Unauthorized ConsumptionCustomer Metering
Inaccuracies
Systematic Data Handling Errors
Apparent Losses
Practical Approach to Water Audits
• Useful in Before Leak Detection
• TOP DOWN Approach
• Pre-Audit Survey – Not Perfect
Who Can Help with Water Audit?
• TAUD – Classes, Circuit Riders
• Engineering Consultant
• Leak Detection Consultant
Why Perform a Water Audit?
A. Because Comptroller says so
B. It’s the law
C. It may actually be useful
D. All of the above
How Can a Water Audit Help with Leak Detection?
• Quantifies Leakage
• Calculates Realistic Leakage Reduction Goals
• Answers: Is leak detection worth it?
What Type of Audit Should I Do?
• TOP DOWN WATER AUDIT
• Use AWWA Software
• AWWA M-36
TIPS for TOP DOWN initial AUDIT
• Keep it simple
• Don’t search endlessly for data
• Set a time deadline (1/2 day)
TIPS for TOP DOWN initial AUDIT
• Pull out last financial annual audit
• Get out your latest water loss calculation sheet from old method
• Use information from the same FY
• GET STARTED!
What Information is Needed for a Quick, Top Down, Water Audit?
1. Distribution System Information
2. Financial Data
3. Operational Data
4. Water Balance Inputs
Distribution System Information
• Miles of Transmission Main
• Number of Service Connections
• Average Operating Pressure
Financial Data
• Total Costs to Operate Water System ($)
• Retail Water Rate ($ per MG)
• Cost to Produce Water ($ per MG)
Water Balance Inputs
MAJOR COMPONENTS
• Water Produced from WTP
• Water Purchased
• Water Billed and Metered to Customers
Water Balance Inputs
Other Components
DON’T GET HUNG UP ON THESE
• Unbilled Authorized Consumption
- Flushing, Fire Dept, Gov’t uses, etc.
• Validities – Calibration Schedules, etc.
Water Balance InputsMinor Components
DON’T GET HUNG UP ON THESE either
• Adjustment for Meter Error (if known)
• Adjustment for Tank Level Difference - (1st Day vs. Last Day of Year)
• Other Adjustments
Water Balance InputsApparent Losses –
• Mistakes, Inaccuracies
• NOT LEAKS
• Most Important = Meter Inaccuracies
Water Balance InputsLet’s look at the AWWA Audit Software…….
Southern Middle TN Community Example Water System - BEFORE LEAK DETECTION.xlsx
What Outputs are Useful for Leak Detection?
• NRW – Non-Revenue Water
• CARL – Current Annual Real Losses
• UARL – Unavoidable Annual Real Losses
• ILI – Infrastructure Leakage Index
NRWNon-Revenue Water
• Don’t Say “Unaccounted For Water” ANYMORE!
• NRW by % of Supply - Traditional
• NRW by % of Operating Costs – REPORT TO COMPTROLLER
Non-Revenue WaterBilled Metered Consumption(including water exported)
Billed Unmetered Consumption
Unbilled Metered Consumption
Unbilled Unmetered Consumption
Unauthorized Consumption
Customer Metering Inaccuracies
Systematic Data Handling Errors
Leakage on Transmission and Distribution Mains
Leakage and Overflows at Utility's Storage Tanks
Leakage on Service Connections up to point of
Customer metering
Figure 1. IWA/AWWA Water Balance (All data in volume for the period of reference, typically one year)
System Input Volume (corrected for known errors)
Authorized Consumption
Billed Authorized Consumption
Revenue Water
Unbilled Authorized
Consumption
Non-Revenue Water (NRW)
Water Losses
Apparent Losses
Real Losses
CARLCurrent Annual Real Losses
• Total Water Leaking from System (MG)
• Calculated Value (not input data)
• CARL/day or CARL/minute – gpm
UARLUnavoidable Annual Real Losses
• May we call him “Earl”?
• Leakage that cannot be reasonably eliminated (MG)
• “U Are Really Low”
UARLUnavoidable Annual Real Losses
• UARL/day or UARL/minute – gpm
• Target Number?
The CARL and UARL Relationship
• CARL and UARL are brothers
• We are parents
• UARL is perfect
• CARL is not
• Our Goal: CARL to be more like UARL
ILIInfrastructure Leakage Index
• CARL divided by UARL
• ILI = 1 is the best we can hope for
• If ILI = 10 then we are leaking about 10 times what we should be
Operational IndicatorsUseful in Leak Detection
• Let’s look at AWWA Audit Software…..
Southern Middle TN Community Example Water System - BEFORE LEAK DETECTION.xlsx
Financial Indicators Justifying Leak Detection
Annual Cost of Real Losses
• How much are my leaks costing me?
• If Annual Cost of Leak Detection and Repair is less than Annual Costs of Real Losses, then is it justified?
Financial Indicators Justifying Leak Detection
Let’s look at AWWA Audit Software….
Water Balance InputsLet’s look at the AWWA Audit Software…….
Southern Middle TN Community Example Water System - BEFORE LEAK DETECTION.xlsx
After the TOP DOWN Audit
• If Audit Justifies Leak Detection
• What’s next?
• Practical Approach to Leak Detection
Practical Approach to Leak Detection
1. Meet and Listen to Utility Staff
2. Investigate System
3. Acoustic Leak Detection
Utility Staff MeetingQuestions
1. Can a map of distribution system and sewer system be provided?
2. How much water are we looking for?
3. From Audit: CARL-UARL = ____ gpm
Effect of the Size of Distribution System on Water Loss
¼” dia = 15,000 gallons/day (625 GPH, 10 GPM)
System #1: 50,000 GPD usage
•Results in a 30% water loss
Effect of the Size of Distribution System on Water Loss
¼” dia = 15,000 gallons/day (625 GPH, 10 GPM)
System #2: 3 MGD usage
• Results in a 0.5% water loss
Pipe Leak Size
Approximate Gallons
Lost/Day
Approximate Gallons
Lost/Month
Approximate Gallons
Lost/Month x 5 Leaks
1/16” 360 11,000 55,000
1/8” 3,100 96,000 480,000
3/16” 8,400 260,000 1,300,000
1/4” 15,000 465,000 2,300,000
Leak Estimation Chart (60 PSI)
50 GPM = 3,000 GPH = 72,000 GPD = 2,160,000 Gallons Per Month =
$6,480 (@$3.00/thousand gallons/month)
Value of a Leak
4. Has there been a gradual increase in water loss?
5. Has there been a large increase recently in water loss?
6. What failures have been found within the distribution system?
Utility Staff MeetingQuestions
Service line failures: polyethylene, galvanized, copper;
Distribution System Failures
Service Line Failures
1.0 Million Gallon/Month Leak ($3000/Month)
IMG_1268.MOV
Main Lines
IMG_1272.MOV
Main line failures: PVC, cast iron, galvanized.
Distribution System Failures
7. What soil types are present? a. Limestone;b. Red clay;c. Sand;d. Sink holes.
Utility Staff MeetingQuestions, cont’d
Sink Hole
Sink Hole
Sink Hole
Sink Hole
Investigate the System
1. Sewer System
a. Check manholes
b. Check flow between manholes
c. Compare water usage of sewer customers v. water metered to sewer plant
2. Storm Drainage
a. Catch basins
b. Monitor where drainage spills out
Investigate the System
Investigate the System
3. River Crossings
4. Cross Country Lines
5. Examine areas that are not visible on a daily, weekly, or monthly basis.
6. Meter Boxes – Automatic Read
Acoustic Leak Detection
1. Start in older sections of system (downtown area)
2. Work outwards to newer areas
3. Daily Leak Log
Acoustic Leak Detection
Acoustic Leak Detection
Acoustic Leak Detection
Billing for Leak Detection
1. By the Mile
2. By the Hour
By the Mile
Based on length of water main surveyed
Pros and Cons:
1. Pro: Fixed Price (Easy to Budget)
2. Con: Unknown Conditions in System
By the HourBased on time required to survey system
Pros and Cons:
1. Pro: Promotes thoroughness
2. Pro: Can be less expensive with Utility’s assistance
3. Con: Price is Variable (Hard to Budget)
Assistance from the Utility
1. Provide an employee
a. Familiar with all meter locations
b. Cuts time by 1/2 +/-
c. Much time spent looking for meters
2. Pre-mark listening points
a. Paint / flag meters
b. Paint arrows in road
c. Can be done by meter reader
Assistance from the Utility
Manual Acoustic Leak DetectionVs.
Correlators
1. Ground microphone – FCS X-Mic
2. PVC and Correlators – Sound conductivity
3. Listening on polyethylene / PVC services
• Short distances
4. Main line PVC leaks:
a. Ground microphone
b. Direct position over main
c. Detector tape
5. Copper services - metallic
Manual Acoustic Leak Detection
6. Alternate methods:
a. Valve pinch off
b. Monitor low use times
Manual Acoustic Leak Detection
Results1. New Factory built in
Clarksville: New 16” DI line – 2000 L.F.
• Contractor: $40,000 on correlators
• Contractor: 2 weeks spot digging
• Rye Engineering: 3 hrs-LEAK FOUND
Results2. Northern KY
town located on Ohio River
• Approx. 4 weeks of leak detection
• 3.3 million gallons/month water loss detected
Results
3. Cumberland River Community
• 3 days of leak detection
• A savings of 600,000 gallons/month
Results
4. Western Montgomery County
• 6 weeks of leak detection
• Savings of 2 million gallons/month
Results
5. Tennessee River community
• 2 days of leak detection
• Found one 6” main line split and one ¾” service
Results6. Clarksville
Housing Authority (120 units)
• 5 days of leak detection
• A savings of 432,000 gallons/month
Results7. Large rural
system in Macon County
• 1 month of leak detection
• Reduced leakage from 54% to 15%+/-
Results8. West TN City
near Mississippi River
• 2 days of leak detection
• With only partial survey reduced to under 20% leakage
CASE STUDY9. Southern Middle TN Community
• Non-Revenue Water = 46% +/- by Volume
• CARL= 103 MG/year
• CARL / min = 198 gpm* = Leakage+/-
• *Utility estimated165 gpm+/- of its flow was being lost due to leakage in March 2013
CASE STUDY
Well Prepared Utility
• Zone Meters in Place
• Isolated Leak to Downtown Area
• Narrowed Search: 30 mi down to 10 mi
CASE STUDY
• 2-1/2 Days of Acoustic Leak Detection
• Real Losses Found = 110 gpm – 150gpm
• 13 Total Leaks – All Service Lines
• REPAIRS MADE DURING LEAK SURVEY
Types of Leaks
Types of Leaks
Repairs
Repairs
Leaks Found
Leaking Into Sewer
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Leaks Found
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Leak Sound - Faint
Goes with Audio 0.MOV
Sound of a Leak - Loud
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Leaks Found
gusher again.MOV
Leaks Found
Service Line Leak with Pump Out.MOV
After Leak Detection
• Re-run Audit Software (for Leak Detection Purposes Only)
• Use Master Meter to Estimate Reduction in Real Losses (extrapolate for 1-year)
• Quantify Results and Compare with Before
• Importance of Repair and Maintenance
Quantify Results with AWWABEFORE Leak Survey
UARL = 20 MG/Year
CARL = 103 MG/Year
ILI = 5.2
NRW (vol)= 46%
NRW ($) = 20%
Real Losses= $190,000/YR
AFTER Leak Survey
UARL = 20 MG/Year
CARL = 26 MG/Year
ILI = 1.3
NRW (vol)= 20%
NRW ($) = 7%
Real Losses= $49,000/YR
Re-run Audit Software
• Let’s go to the AWWA Audit Software…
Southern Middle TN Community Example Water System - PROJECTIONS AFTER LD.xlsx
Audit Phenomena
• Use the Audit Software to try what-ifs
• Does it encourage higher operating costs?
• How can a system with NRW = 46% (vol) not be in violation?
• What to do with the money saved?
What can you do with Money Saved?
• Spend?, Invest?, Save?
• Replace Lines?
• Replace Services?
• Timeliness
Pros and Cons of Purchasing Your Own Leak Detection Equipment
• Cost of Equipment
• Dedicated Employee(s) Cost
• Training
• Shelving It!
The Human Elements of Leak Detection
• It’s the Person – Not the equipment
• Experience in Water Distribution Systems
• Not just “Technicians”
• Grabbing the Low Hanging Fruit
RYE ENGINEERING PLCConsulting Engineers & System Operators
4210 West Main StreetErin, TN 37061
Phone: (931) 289-2300Fax (931) 289-2313
Leak Detection Services
THANK YOU!
ryeleak detection931-289-2300