Water Services National Training Group and

National Federation of Group Water Schemes

7th Annual Rural Water Services Conference

18th September 2008

Treated WaterDemand Management,

Leakage Control & Conservation

Joe GallagherN.F.G.W.S

Introduction

• The Need for Water Demand Management?

• Implications of high Unaccounted for Water (UFW)

• Reducing UFW on Group Water Schemes

• New Training Course

Reducing daily water demand on Group Water Schemes

Why is there a need for Leakage Control on Group Water Schemes?

Example of DBO Schemes in Year 2 of O&M Contract

GWSDesign

Demand m3/day

Actual Usage

m3/day

% of Design

DemandComments

A 246 391 158% GWS in middle of upgrade – installing meters

B 68 102 150% Planning a full network upgrade & metering

C 182 243 133% Meters not yet installed

D 112 141 125% Only meters on farm connections

E 560 613 109% Not charging on the meters

F 362 370 102% Not charging on the meters

G 366 244 94% Upgrading works ongoing

H 67 50 75% GWS charging on meters

I 210 117 55% GWS charging on meters

Reasons Schemes exceed design demand• Deficient distribution networks

– Major leaks– Lack of PRVs

• Lack of Metering– Bulk Meters– Universal Meters

• Charging policies– Over reliance on flat rate charging– Resistance to realistic usage charge

• Unknown Sources of Demand

Leakage in Distribution Mains Vs Consumer Side

• Leakage across 6 GWS in Co. Mayo

GWS Distribution System Consumer Side

1 13% 87%

2 15% 85%

3 26% 74%

4 30% 70%

5 34% 66%

6 45% 55%

Slide Sourced from Ryan Hanley Consulting Engineers

What are the Implications of UFW?

• Cost

• Capacity of treatment plant

• Sustainability of source

• Quality

• Supply & pressure

Galway GWS (90 Houses)

May 2006 Target

Daily demand 142 m3/day 71 m3/day

UFW % (m3/day) 60% (85) 20% (14)

Cost of UFW (Savings)

€10,835.40/year €1,761.91/year (€9,073.49)

Distribution System 35% UFW

Consumer Side 65% UFW

10 connections accounted for 45% of daily demand.

Burst in Distribution Pipe Network• At a pressure of 30m (3 bar) the following losses

will occur:Size of hole m3/day € Cost /day (@ 80 Cent per

m3)

1mm 1 €0.80

3mm 9 €7.20

5mm 25 €20.00

7mm 44 €35.20

Av. Mains Leak 74 €59.20

Slide Sourced from WSNTG Leakage Control in Rural Supply Networks

Extent of Water Loss From Leaks/Bursts• At a pressure of 30m (3 bar) the following losses

will occur:Size of hole m3/day Cost/day

(@ 80 Cent/m3)

Cost/yr

(@80 Cent/m3)

1mm 1 €0.80 €292.00

3mm 9 €7.20 €2,628.00

5mm 25 €20.00 €7,300.00

7mm 44 €35.20 €12,848.00

Av. Mains Leak

74 €59.20 €21,608.00

Slide Sourced from WSNTG Leakage Control in Rural Supply Networks

The Cost of Water

Typical Litre of bottled water €1.20

What is this load worth? A 450m3 reservoir @ €1.20/l would store water worth €540,000

Cost Implication for Scheme Members

No. 2005

(m3)

2006

(m3)

Leakage

m3 Cost

1 114 7,609 7,495 €5,996.00

2 9,577 15,300 5,723 €4,578.40

3 173 4,805 4,632 €3,705.60

4 5,777 8,681 2,904 €2,323.20

5 709 2,186 1,477 €1,181.60

6 4,495 5,686 1,191 €952.80

7 363 755 392 €313.60

Figures from a GWS:

• GWS charge is 80 cent/m3 (€3.60 per 1,000 gallons)

Capacity of Treatment Plant

• Ability of Treatment Facility to cope

– Design Demand

– GWS with high UFW reach their Design Demand much more quickly

– Plant failure, water outages and/or failures in water quality

Sustaining the Source

• Excessive abstraction

– This will impact on surface and groundwater supplies and may result in:

• Slower recharge of the source

• Poor quality raw water being drawn into the treatment plant

• Increased costs for monitoring and treatment

Sustaining the Source

Supply & pressure

• Potential difficulty in admitting new members

– A scheme with 50% UFW has the capacity to increase its domestic membership by a third when UFW is reduced to 25%!

• Members situated on the network beyond a leak in the system may be affected by poor pressure and breaks in supply

Calculating Legitimate Demand

• Average daily usage figures from the National Water Study:

Demands People Cows Dry Stock Others

Litres/hd/d 136 90 45 5

• Schemes need to estimate the numbers served on the scheme in relation to:– Human population – Dairy Cows– Drystock– Others (e.g. Sheep/Calves/Poultry/Mushroom)

Setting Targets• 25% UFW is considered acceptable, but is it enough?

• Kilmaley Inagh GWS – 1900 Houses with < 10% UFW:

– Installing /Monitoring district & consumer meters

– Isolating the network into District Metering Areas (DMAs)

– Repairing leaks and replacing critical mains

– Monitoring the distribution network on a consistent basis

– Implementing realistic pricing policies, based on usage

Setting TargetsErne Valley GWS - > 1,100 Houses (2007 Figures)

• Original Usage 5,700 m3/day

• Target 3,000 m3/day

• 2007 usage 3,300 m3/day

• 2008 usage 2,900 m3/day

• UFW (REDUCTION) 2,800 m3/day

• 49% Reduction

• Saving to Scheme > €250,000 aprox. p.a.

M

District Meter

• Reduce Distribution Network to < 25% UFW

Reducing UFW in Distribution Network

4” Pipe

3” Pipe

2” Pipe

Service Pipe

Consumer Meter Box

M

SV

SV

District Meter

• Reduce Distribution Network to < 25% UFW• Typical District Metered Area

Reducing UFW in Distribution Network

4” Pipe

3” Pipe

2” Pipe

Service Pipe

Consumer Meter Box

M

SV

SV

PRV

Critical Mains Rehab

District Meter

Pressure Reduction ValveReducing Pressure from 70m to 40m should

reduce leakage by 55%

Consumer Meter Box

• Reduce Distribution Network to < 25% UFW• Typical District Metered Area

• Possible solutions identified

• Consult with GWS Engineer

Reducing UFW in Distribution Network

Leaks

GWS with 90 Houses• What Caused this Fluctuation in Measured Daily Usage on this GWS?

GWS with 90 HousesMeters Installed

GWS with 90 HousesMeters Installed Bills Issued

Mayo GWS (150 Houses)

• This Part - Private Mayo GWS successfully reduced its UFW through:

– Active Leakage Control

– Critical Mains Replacement

– Pressure Reduction

– Demand Management

Mayo GWS (150 Houses)

Mayo GWS Before After

Operating System 1 booster zone 2 zones – gravity + booster

No. of Domestic Connections 150 150

Demand into Supply 479m3/day 185m3/day

UFW 334m3/day (70%) 20m3/day (11%)

Cost of UFW/year @ 80cent/m3 €70,373 €5,840

• The results can be seen in the table below:

Reducing daily water demand on Group Water Schemes

• Requirement for training in Water Demand Management

• Developed by the NFGWS as an introductory course to be delivered to the GWS sector in advance of the more detailed WSNTG course:

“Leakage Control in Rural Supply Networks”

Course objective

• To provide a practical framework for schemes dealing with high levels of water wastage, in particular unaccounted for water (UFW)

and • To assist those schemes wishing to maintain

and improve their current low levels of water wastage and UFW.

Course Format

• Four Modules

– Module 1: What is UFW?– Module 2: What are the implications of UFW?– Module 3: How can UFW be quantified?– Module 4: How can UFW be reduced?

Conclusion• High UFW will have cost, capacity and supply implications for

GWS and the individual member

• High UFW may affect the sustainability of the source and also the quality of water supplied

• UFW must be reduced

• This Course is design to do exactly that– Delivered in your locality– < 3 Hours to complete– At €75 per head it’s a steal!!

Contact Details

Joe Gallagher & Barry DeaneTraining Co-ordinators

N.F.G.W.S.12 Henry Street

TullamoreCo. Offaly

Tel / Fax: 057 9328068

Water Services National Training Group and

National Federation of Group Water Schemes

7th Annual Rural Water Services Conference

18th September 2008