rye

rye leak detection931-289-2300

A PRACTICAL APPROACH TO WATER AUDITS AND LEAK DETECTION • Presented By: R RYE ENGINEERING PLC Consulting Engineers & System Operators Friday, March 15, 2013

Leak Detection Services RYE ENGINEERING PLC Consulting Engineers & System Operators 4210 West Main Street Erin, TN 37061 Phone: (931) 289-2300 Fax (931) 289-2313

Experience and Qualifications • Mike 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 Balance

Real Losses

Real Losses • Water Main Leakage Service Line Leakage

Apparent Losses Encountered

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? • Because Comptroller says so • It’s the law • It may actually be useful • 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? • Distribution System Information • Financial Data • Operational Data • 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 Inputs • Minor 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 Inputs • Apparent Losses – • Mistakes, Inaccuracies • NOT LEAKS • Most Important = Meter Inaccuracies

Water Balance Inputs • Let’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

NRW Non-Revenue Water • Don’t Say “Unaccounted For Water” ANYMORE! • NRW by % of Supply - Traditional • NRW by % of Operating Costs – REPORT TO COMPTROLLER

Non-Revenue Water

CARL Current Annual Real Losses • Total Water Leaking from System (MG) • Calculated Value (not input data) • CARL/day or CARL/minute – gpm

UARL Unavoidable Annual Real Losses • May we call him “Earl”? • Leakage that cannot be reasonably eliminated (MG) • “UAre Really Low”

UARL Unavoidable 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

ILI Infrastructure 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 Indicators Useful 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 Inputs • Let’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 • Meet and Listen to Utility Staff • Investigate System • Acoustic Leak Detection

Utility Staff Meeting Questions • Can a map of distribution system and sewer system be provided? • How much water are we looking for? • 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

Leak Estimation Chart (60 PSI)

Value of a Leak 50 GPM = 3,000 GPH = 72,000 GPD = 2,160,000 Gallons Per Month = $6,480 (@$3.00/thousand gallons/month)

Utility Staff Meeting Questions • Has there been a gradual increase in water loss? • Has there been a large increase recently in water loss? • What failures have been found within the distribution system?

Distribution System Failures • Service line failures: polyethylene, galvanized, copper;

Service Line Failures

1.0 Million Gallon/Month Leak ($3000/Month) • IMG_1268.MOV

Main Lines • IMG_1272.MOV

Distribution System Failures • Main line failures: PVC, cast iron, galvanized.

Utility Staff Meeting Questions, cont’d • What soil types are present? • Limestone; • Red clay; • Sand; • Sink holes.

rye

Télécharger la présentation

Plus de contenu associé