Document

Report
Water Services National
Training Group
Best Practice in the Management of
Drinking Water
Water Conservation
Lar Spain
Senior Engineer
Fingal County Council
Water Conservation - Context
Financial – Treatment, Pumping, etc.
 Leakage Control pays for itself.
 Service to customer improves.
 Ecological – Waste of resources,
Sustainability.
 Public Health – WTP’s overstretched

What is Water
Conservation/Leakage Control?
?
What is Leakage Control?

Is it this….
What is Leakage Control?
Or This….
What is Leakage Control?

Or is it this…
What is Leakage Control?

Active Leakage Control


Leak finds you – Easy.
You find leak – Hard.

70% to 80% of Active Leakage Control
is spent gathering and refining data.

DATA IS THE KEY!
Spot the Difference…..
Both are Leaks.
 LHS Service Leak – RHS a 150 mm Burst.
 LHS “Reported” – RHS “Unreported”.

Active Leakage Control - DMA’s





Looking for unreported bursts/leaks in a county is like
looking for needles in a field of haystacks.
DMA’s - tell you which haystacks (DMA’s) have
needles and which don’t.
Allows you to target your resources.
Subdivide county into District Metered Areas (DMAs)
and measure flow into each DMA.
Try to have no more than 1,000 properties in each
DMA (Urban Areas – Rural dictated by geography).
Benefits of DMA’s
Identify unreported bursts and leaks.
 Reduce leakage runtime.
 Prioritisation of target areas for leakage
inspectors.
 Can tell you number of Service Leaks
and/or Mains Bursts that you have to find.
 Network performance can be monitored.
 Data available for design, planning and
forecasting.

District Meter Areas
District Meter Areas are:
• Metered Areas feed by a single
supply (not always).
• Designed to accommodate a
maximum of 1,000 properties
(Domestic and Non Domestic –
Urban/Rural differences).
• Connected to the regional
Telemetry Network or logged to
enable remote monitoring.
Typical DMA Meter
Fingal has:
•
111 DMA’s County wide
•
3 New DMA’s will be created every year for the next 5 years
Water Audits
DMA Inflow
- Domestic Demand
- Non-Domestic Demand
- Customer Losses
- Operational Usage
Net Distribution Losses (UFW)
Leakage is part (most) of UFW
Domestic Demand

Has to be estimated – we use 148
l/person/day.

The Per Capita Consumption (PCC) Figure
can be exceeded (>148 l/person/day) –
makes UFW increase (in hot weather for
example).

Accurate Population Figure also needed.
Non-Domestic Demand
Meter error.
 Meters being bypassed.
 Unmetered Non-domestics (should be gone).
 Illegal tappings off mains.
 Mobile Vehicles eg. Road
sweepers/commercial tankers filling from
hydrants.
 Fire Flows.

Losses and Usage

Customer Losses - 64.36 l/prop/day (average)

Operational Usage – 1.2 l/person/day (fire
hydrants, flushing mains, road sweepers etc.
by the Local Authority)
Leakage Team - Tasks
Tracking house counts/population.
 Better estimates for PCC.
 Gathering Meter Readings – question.
 Metering missed Non-Domestics.
 Chasing new Non-Domestics.
 Chasing as-built drawings.
 Confirming/correcting record drawings.

Leakage Team - Tasks
Drop-Testing DMA’s – to check for integrity
and/or breaches.
 Checking Boundary Valves.
 Drop-Testing Reservoirs.
 Installation/Retrieval of Loggers.
 Step Testing.
 Sounding.
 Correlating.

Leakage Team - Training
Large commitment to Training required.
 Can take some time to “get up to speed”.
 Issue when staff changes – particularly
Engineer.
 WSNTG – existing training courses – being
updated – ready Spring 2009.

Network Management & UFW
•Network Management - understanding Network - where water is
being used.
•Identifying Unaccounted-for Water (UFW) - big challenge.
Achieved by undertaking a series of analytical steps:
•
Water Audits (Trunk and Distribution Mains).
•
•
•
Water Supply Area (WSA) and District Meter Area (DMA) Audits.
Commercial Audits.
Domestic Usage Audits (Per Capita Consumption).
Locating Leaks
•Audits confirm a leak as the
reason for the UFW.
•Locate the Leak(s)
• Step Testing - Breaking a DMA
into sections to narrow down
where the leak may be.
• Leak Location – Aural Sounding
using listening sticks (Traditional
Method) or using electronic
acoustic equipment to identify the
leak
Mains Burst
The most important activity in this
process is to EXPEDITE the leak
repair.
Mains Burst when identified should
be repaired within 24 hours.
Operational Barriers
Operational Barriers (UFW Show Stoppers)
•
Lack of clear as-laid information on new infrastructure constructed by
others
•
Quality of Workmanship
•
Standard of Materials used
•
Boundary Breaches – operational changes.
•
Getting repairs done quickly.
Recent Example of Qualtiy of Workmanship:
•In 5 NEW Estates in Balbriggan [2,000 Houses] – 111 Leaks were located.
•All of these were down to the Quality of Workmanship
Pressure Management
Pressure Management:
• Is a proactive method of protecting vulnerable infrastructure.
• Extends the asset life of the pipe network.
• Reduces burst frequency.
• Also Reduces amount of Leakage.
Fingal has:
•
29 PRV’s County wide
•
10 Further Locations
under consideration
Typical Cast Iron Pipe
Sample
Glen Ellen, Swords
Before :
Reduction
After :
Pressure
Management
•Pressure - 52m
•Pressure - 35m
•Flow - 43.5m3/hr
•Flow – 25.8m3/hr
•Flow – 41%
•Pressure – 46%
Pressure Management
Day/Night Controllers
Day/Night Controller on trial in Donabate
DMA.
 Night-time pressures (0:00 to 06:00) reduced
from 28m to 20m.
 Reduced flows by 10m3/hr for this period.
 Total saving over 6 hrs =60m3 =approx. daily
water supply for 130 houses.

Fingal DMA’s
Typical DMA
Fingal’s Leakage Team
1 Leakage Engineer (Exec).
 1 Leakage Supervisory Inspector.
 4 Leakage Inspectors.
 1 General Operative.
 All DMA meters connected to Regional
Telemetry System.


Repairs by Maintenance Crews.
Example - Savings
Example: River Valley DMA

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16 No. Leaks Detected between 19th Sept. – 3rd Oct
2006
16 No. Leaks repaired between 22nd Sept. – 17th Oct
2006
Compare flows into DMA
before leaks detected (5th – 8th Sept.)
v’s
after leaks repaired (12th – 15th Dec.)
Saving of approx. 25 m3/hr at 4am = 500 m3/day
= daily usage for 1,100 houses.
Leaks Found Nov 07 – Oct 08
Nov 07
17
Dec 07
12
Jan 08
32
Feb 08
108
Mar 08
40
Apr 08
57
May 08
36
Jun 08
27
Jul 08
12
Aug 08
15
Sept 08
19
Oct 08
20
Total = 395
Leaks Found by Type
Leak on Main
12 (3.0%)
Leak on Fitting (hydrant,
stopcock,valve, etc.)
Leak on Meter Box
141 (35.6%)
Leak on Communication
Pipe
Private side leaks
160 (40.4%)
24 (6.1%)
59 (14.9%)
Fingal UFW 2008
38%
32%
30%
2008
2007
2006
28%
26%
24%
22%
20%
Jl
y
Au
g
Se
pt
O
ct
N
ov
D
ec
18%
Ja
n
Fe
b
M
ar
Ap
r
M
ay
Ju
n
Percentage
36%
34%
Month
Summary
Active Leakage Control – the only way.
Accurate data is the key – continue to
refine.
Leakage Teams need long-term
support.
Water Conservation is not a “Project” –
it’s never ending.
Resources need to be committed for the
long term.

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