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

Goes with Audio.MOV

Leaks Found

Goes with Audio - 1.MOV

Leak Sound - Faint

Goes with Audio 0.MOV

Sound of a Leak - Loud

Goes with Audio 1.MOV

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