Contents

Introduction

Fire Hydrants

Aging Infrastructure

Active Leak Detection

Passive Leak Detection Passive Leak Detection with AMR

Comparison of Active and Passive Technologies

Conclusion

Introduction: Location

Albuquerque, New Mexico

Introduction: Issue

Drought conditions for at least past decade

Population increase of roughly 20%

Residents are being asked to conserve

So…

Albuquerque Bernalillo Water Utility Authority must reduce water losses as much as possible

Introduction: Challenge

Determine applicable strategies to reduce water losses in a way that:

Makes sense

Is economical

Is feasible

Fits within current operations

Water Audit

Water Supplied

Real Water Losses

5%

(Total Non-Revenue Water 18%)

Fire Hydrants

Prior to Study

14,121 Hydrants in distribution system

Estimated water loss 1% of total loss

Question: Should Repairing all Fire Hydrants Be a Part of a Strategic Water Loss Reduction Strategy?

Fire Hydrants

Study

All 14,121 Hydrants were searched for

Data collected on each one

Results

13,694 were found

416 were found to be leaking

Fire Hydrants

Water Loss Estimates

22 MG to 383 MG/Year

Some hydrants would be repaired w/o a FH program

Incremental savings: 10 MG to 180 MG/Year

Overall savings 0.5% to 1%

Fire Hydrants

Conclusion

Not worth the effort of a full FH survey

Should only survey the grid zones (1 mile square areas of the city) with majority of hydrants installed before 1970 and those manufactured by certain manufacterers

Could cut workload to a fraction of the area and still receive most of benefits

Aging Infrastructure

Infrastructure Study Results

2,500+ miles of pipe

5% of System is steel pipe ~60 years old & causes 50% of the breaks

Question: How Should Aging Infrastructure be Addressed as Part of a Strategic Water Loss Reduction Strategy?

Aging Infrastructure

Money available for pipe replacement

$1 - $3 million/year

Cost of 1 mile of pipe replacement ~ $500,000

Therefore, 2 to 6 miles/year could be replaced

Even at $3 M/Year could take almost 20 years to replace all steel pipe

Therefore, How to Decide??

Aging Infrastructure

Used Asset Management Approaches to Choose Pipe Segments with

High probability of failure

High consequence of failure

Aging Infrastructure

Probability of Failure factors Number of breaks

Age

Location (soil types, landfills)

Other known history

Consequence of Failure Critical customers

Hard to repair areas

High traffic corridors

Aging Infrastructure

Using this approach

10 years worth of pipe segments were identified for replacement

Early results show a reduction in pipe breaks from 50% to 35% of the breaks from steel pipe

Conclusion

A strategic replacement approach can reduce water loss from aging infrastructure

Active Leak Detection

Active leak detection involves listening to distribution system; crew systematically goes through the system listening to assets to hear leaks

Question: Should active leak detection be part of an overall strategy?

Active Leak Detection

Limited to one crew

Crew has additional duties

Had to obtain trust of repair crews; initially repair crews didn’t trust results

After some success, trust has increased

Active Leak Detection Conclusion:

Not yet big enough part of Strategic Loss Reduction

Being used mostly to find location of leaks called in by customers, rather than proactively looking throughout system for leaks

Passive Leak Detection

Passive leak detection involves installing devices on valves and/or meters. Devices listen for noise and report an alarm if noise is heard

Question: Should passive leak detection be part of an overall strategy?

Passive Leak Detection

Two types of devices were tested: Permalog and Zonescan

Passive Leak Detection Deployed on the same areas to judge results,

ease of use, time to deploy

Results: Time to deploy similar

Neither device found all leaks present (9 found that neither device found)

Both devices found “ghost leaks”

Conclusion: Zonescan was determined to be easier to use, however, a trained staff is a necessary component

Passive Leak Detection Integrated with AMR Technology Passive leak detection integrated with AMR

metering involves installing passive leak detection devices such that reporting occurs through the AMR system

Question: Should passive devices be installed with AMR as these devices are added to the system?

Passive Leak Detection Integrated with AMR Technology

Looked at Permalog units attached to AMR meters

Chose one small area to test

Initially, devices did not read properly

No leaks were reported for several months (no leaks or no reports???)

Passive Leak Detection Integrated with AMR Technology

Created leaks in fire hydrants to test devices

Did not register leaks

Two devices went into alarm mode, but no leaks were present

Conclusion: Devices are not yet worth the price to install along with AMR, given the results

Comparison of Active & Passive Leak Detection

Question: How do active and passive leak detection methods compare?

Comparison of Active & Passive Leak Detection Active better able to find house side &

hydrant leaks

Passive finds more “ghost leaks”

For one pass, active cheaper

Passive devices did not hold up well to field conditions (70% failed within 3 years)

Comparison of Active & Passive Leak Detection Both technologies require trained staff, skilled

technician (active even more so)

Desire to fix leaks that are found is essential; water only saved when leaks fixed!!!

Amount surveyed must match what can reasonably be repaired

Conclusion: Both practices can find leaks faster than waiting for them to surface

Conclusion

Strategic water loss reduction is very important

Program will include a variety of strategies:

Fire hydrant surveys

Replacement of aging infrastructure

Combination of active and passive leak detection

Additional approaches are still being investigated

Questions

Comments

Concerns

Heather Himmelberger, P.E. Director, NM EFC 1-505-924-7028 heatherh@efc.nmt.edu http://nmefc.nmt.edu