1. Water Services Network Management1
Water Services Network Management
Grellan McGrath
Steven Blennerhassett
RPS Consulting Engineers

2. 2
Mizen Footbridge

3. 3 ?

4. 4

5. World Water Day – 22nd March5
World Water Day – 22nd March
“When the well is dry, we know the value of water” – Benjamin Franklin

6. World Water Day – 22nd March6
World Water Day – 22nd March

7. A Brief History of Cork City’s Water Supply7
Cork Pipe Water Company Established
Timber distribution pipes, 20ft long – 2 ½” to 3” ø
Cork Bridges, Waterworks and Improvement Act
Cast iron mains introduced – network extended.
1879 – Filter tunnel constructed
“intense waste water campaign” due to efforts of city engineer and inspectors reduced consumption from 70 to 38 gal/p/d (172 l/p/d)
1928 – Sand filters installed
1940’s - new high level reservoir built as an unemployment relief scheme
1956 – New filters and sedimentation plant

8. Network Planning 8 Water Network Management Review & Improve
Financial Plan
Define / Review
Levels of Service
Water Network
Management
Management Plan
Demand
Assessment
Collect Network
Asset Data
Improvement
Options
Capacity
Assessment

9. Network Planning Levels of Service Statutory Customer9
Levels of Service
Define / Review
Levels of Service
Statutory
Water Quality – SI 278/2007
Customer
Service Pressures -15 to 40m Head
Other Service Standards
Leakage - Economic Level
Fireflows – 8 to 75 l/s depending on area served
Service Storage - 24 hr

10. Network Planning Demand Assesment Current Demand - Water Audit 10
Assessment

11. Network Planning Demand Assesment Current Demand - Water Audit 11
Distribution Input
(DI)
Accounted
for
Water
(AFW)
Measured or assessed
lergitimate
water use
Domestic Demand
Households x Occupancy x pcc
Permanent Domestic
Seasonal Domestic
Demand
Assessment
Non-Domestic Demand
Metered consumption
Operational Use – 2% of DI
Unaccounted for
Water
(UFW) = DI - AFW
Peaking Factor – Average Day/Peak Week

12. Network Planning Demand Assesment Current Demand Demand Management12
Demand Assesment
Current Demand
Demand Management
Reduce water losses
Demand
Assessment
Reduce water consumption

13. Network Planning Demand Assesment Current Demand Demand Management13
Demand Assesment
Current Demand
Demand Management
Future Demand
Population growth (25-Year Horizon)
- Top Down: Planning guidelines, CSO
- Bottom Up: Availability of zoned land
Demand
Assessment
Demand
– Domestic demand as per audit using projected pcc, losses etc.
- Non-domestic demand growth in line with domestic
- UFW in line with level of service objectives.

14. Network Planning Asset Data - National Water Study 2000 14
Length of network (size, age, material, condition, performance)
Number/capacity of pumping stations
Number and total volume of storage reservoirs
Value of total asset (Modern Equivalent Asset (MEA) value)
Value of assets to be replaced over next 5 years (MEA value)
Annual operating and maintenance costs.
Collect Network
Asset Data

15. Network Planning Asset Capacity Assessment 15 Demand / Capacity
Design Horizon
Demand / Capacity
Yrs
Yrs
0 - 5 Yrs
Yrs
Yrs
Projected Demand Range
Expected Time Range of Deficit
Capacity Shortfall
Rated Asset Capacity
Capacity
Assessment

16. Increased Asset Capacity
Network Planning 16
Asset Capacity Assessment
Increased Asset Capacity
Design Horizon
Demand / Capacity
Yrs
Yrs
0 - 5 Yrs
Yrs
Yrs
Expected Time Range of Deficit
Rated Asset Capacity
Capacity
Assessment

17. Assess Capacity Requirement
Network Planning 17
Improvement Options
Assess Capacity Requirement
Can it be satisfied by
Operational Optimisation?
Proceed with selected option
Yes
Can it be satisfied by
Rehab/renewal option? No
Yes
Can it be satisfied by
Augmentation Option? No
Yes
Can it be satisfied by
Upgrade/Replacement? No
Yes
Improvement
Options

18. Network Planning Management Plan 18 Asset Inventory – As per NWS
Operational Plan – Summary of primary objectives in the operational plan and any sub-plans
Management Plan
Maintenance Plan – Summary of the planned asset maintenance.
Rehabilitation/Renewal Plan – Summary of the planned asset rehabilitation/renewal activities.
Asset Replacement – Summary of the planned asset replacement.

19. Sustainable level of expenditure to cover future investment needs
Network Planning 19
Financial Planning
Financial Plan
Water Services Expenditure Requirements
Funding for
Loan Repayment
Sustainable level of expenditure to cover future investment needs
Funding for
System Growth
Funding for
Service Enhancement
Funding for
Historic Under-investment
Asset Depreciation
Covering cash costs and providing for maintaining current asset condition – no planning for the future
Interest Expenditure
(if any)
Just covering cash costs
Operation and Maintenance
Expenditure

20. Network Planning Review Levels of Service Demand for Water Services20
Review &
Improve
Review
Levels of Service
Demand for Water Services
Asset Management
Finance

21. European Communities (Drinking Water)
Legislation 21
European Communities (Drinking Water)
(No. 2) Regulations 2007
S.I. No. 278 of 2007
Came into immediate effect on
12 June 2007

22. Microbiological Parameters
Legislation 22
Ensure Quality (Regulation 4)
Table A
Microbiological Parameters
No.
Parameter
Value (no./100ml) 1
Escherichia coli (E. coli) 2
Enterococci

23. Table B Chemical Parameters
Legislation 23
Table B Chemical Parameters
Ensure Quality (Regulation 4)
No.
Parameter
Value (μg/l) 3
Acrylamide
0.10 4
Antimony
5.0 5
Arsenic 10 6
Benzene
1.0 7
Benzo(a)pyrene
0.01 8
Boron
1.0 mg/l 9
Bromate
Cadmium 11
Chromium 50 12
Copper
2.0 mg/l 13
Cyanide 14
1,2-Dichloroethane
3.0 15
Epichlorohydrin
0.1 16
Fluoride (a) fluoridated supplies
0.8 mg/l
Fluoride (b) naturally occurring fluoride, not needing further fluoridation
1.5 mg/l
No.
Parameter
Value (μg/l) 17
Lead – to 24/12/13 25
Lead – from 25/12/13 10 18
Mercury
1.0 19
Nickel 20
Nitrate
50 mg/l 21
Nitrite
0.5 mg/l 22
Pesticides
0.1 23
Pesticides Total
0.5 24
PAH
Selenium 26
Tetrachloroethene and Trichloroethene 27
Trihalomethanes – Total
100 28
Vinyl chloride

24. Table B Chemical Parameters
Legislation 24
Table B Chemical Parameters
Ensure Quality (Regulation 4)
No.
Parameter
Value (μg/l) 3
Acrylamide
0.10 4
Antimony
5.0 5
Arsenic 10 6
Benzene
1.0 7
Benzo(a)pyrene
0.01 8
Boron
1.0 mg/l 9
Bromate
Cadmium 11
Chromium 50 12
Copper
2.0 mg/l 13
Cyanide 14
1,2-Dichloroethane
3.0 15
Epichlorohydrin
0.1 16
Fluoride (a) fluoridated supplies
0.8 mg/l
Fluoride (b) naturally occurring fluoride, not needing further fluoridation
1.5 mg/l
No.
Parameter
Value (μg/l) 17
Lead – to 24/12/13 25
Lead – from 25/12/13 10 18
Mercury
1.0 19
Nickel 20
Nitrate
50 mg/l 21
Nitrite
0.5 mg/l 22
Pesticides
0.1 23
Pesticides Total
0.5 24
PAH
Selenium 26
Tetrachloroethene and Trichloroethene 27
Trihalomethanes – Total
100 28
Vinyl chloride
No.
Parameter
Value (μg/l) 17
Lead – until 24th December 2013 25
Lead – from 25th December 2013 10

25. Table B Chemical Parameters
Legislation 25
Table B Chemical Parameters
Ensure Quality (Regulation 4)
No.
Parameter
Value (μg/l) 3
Acrylamide
0.10 4
Antimony
5.0 5
Arsenic 10 6
Benzene
1.0 7
Benzo(a)pyrene
0.01 8
Boron
1.0 mg/l 9
Bromate
Cadmium 11
Chromium 50 12
Copper
2.0 mg/l 13
Cyanide 14
1,2-Dichloroethane
3.0 15
Epichlorohydrin
0.1 16
Fluoride (a) fluoridated supplies
0.8 mg/l
Fluoride (b) naturally occurring fluoride, not needing further fluoridation
1.5 mg/l
No.
Parameter
Value (μg/l) 17
Lead – to 24/12/13 25
Lead – from 25/12/13 10 18
Mercury
1.0 19
Nickel 20
Nitrate
50 mg/l 21
Nitrite
0.5 mg/l 22
Pesticides
0.1 23
Pesticides Total
0.5 24
PAH
Selenium 26
Tetrachloroethene and Trichloroethene 27
Trihalomethanes – Total
100 28
Vinyl chloride
No.
Parameter
Value (μg/l) 27
Trihalomethanes - Total
100

26. Legislation Table C Indicator Parameters Ensure Quality (Regulation 4)26
Table C Indicator Parameters
Ensure Quality (Regulation 4)
No.
Parameter
Value 29
Aluminium
200 μg/l 30
Ammonium
0.3 mg/l 31
Chloride
250 mg/l 32
Clostridium perfringens
Zero No./100ml 33
Colour
Acceptable to consumers & no abnormal change 34
Conductivity oC 35
Hydrogen Ion Concentration
≥6.5 & ≤9.5 36
Iron 37
Manganese
50 μg/l 38
Odour
No.
Parameter
Value 39
Oxidisability
5mg/lO2 40
Sulphate
250 mg/l 41
Sodium
200 mg/l 42
Taste
Acceptable to consumers & no abnormal change 43
Colony count 22oC
No abnormal change 44
Coliform bacteria
Zero no./100ml 45
Total Organic Carbon (TOC) 46
Turbidity

27. Legislation Table C Indicator Parameters Ensure Quality (Regulation 4)27
Table C Indicator Parameters
Ensure Quality (Regulation 4)
No.
Parameter
Value 29
Aluminium
200 μg/l 30
Ammonium
0.3 mg/l 31
Chloride
250 mg/l 32
Clostridium perfringens
Zero No./100ml 33
Colour
Acceptable to consumers & no abnormal change 34
Conductivity oC 35
Hydrogen Ion Concentration
≥6.5 & ≤9.5 36
Iron 37
Manganese
50 μg/l 38
Odour
No.
Parameter
Value 39
Oxidisability
5mg/lO2 40
Sulphate
250 mg/l 41
Sodium
200 mg/l 42
Taste
Acceptable to consumers & no abnormal change 43
Colony count 22oC
No abnormal change 44
Coliform bacteria
Zero no./100ml 45
Total Organic Carbon (TOC) 46
Turbidity
No.
Parameter
Value 33
Colour
Acceptable to consumers & no abnormal change 38
Odour 42
Taste 46
Turbidity

28. Focus Shift 28
Quality
Quantity
Quality
Quantity

29. Factors Influencing Microbial Change in Water Distribution Systems
Quality Issues 29
Factors Influencing Microbial Change in Water Distribution Systems

30. Quality Issues 30
Loss of Disinfection Residual

31. Quality Issues 31 Loss of Disinfection Residual
All water entering distribution systems should be disinfected
Treated water should contain chlorine residual of 0.5mg/L for 30mins contact time prior to supply
Residual should be monitored before entering distribution
Maintain residual of at least 0.1 mg/L at the extremity of the network
EPA Guidance on Chlorination

32. Quality Issues 32 Loss of Disinfection Residual Rate of Loss
Up to 50% lost during primary disinfection (first few hours)
Rate of loss thereafter reduces significantly and depends on:-
- Temperature
- Reactivity of organic carbon in water
- Reactivity of Pipe wall – “wall demand”
Half life after primary disinfection can vary from several days to several weeks but can reduce to several hours with high demand.

33. Quality Issues 33 Loss of Disinfection Residual Mitigation
Use chloramines for secondary disinfection – longer lasting
Pipe flushing, relining or replacement to reduce “wall demand”
Reduce residence times in storage.
Install booster chlorination facilities
Reduce total level of organic carbon in treatment process.
Mitigation

34. Quality Issues 34 Loss of Disinfection Residual
Growth of Disinfection By-products

35. Quality Issues 35 Loss of Disinfection Residual
Growth of Disinfection By-products
Reaction of chlorine with naturally occuring organic matter
Most common by-products are Trihalomethanes (potential carcinogens)
Amount of THM production depends on:-
- pH
- Temperature
- Chlorine dose
- Amount of organic precursor
- Reaction time

36. Quality Issues 36 Loss of Disinfection Residual
Growth of Disinfection By-products
Prevention
Remove organic precursors during treatment
Change disinfectant (Chloramines)
Reduce water age in distribution system (quicker turnover)

37. Quality Issues 37 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution

38. Quality Issues 38 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Contributing Factors
Flow – Stagnant conditions promote tuberculation and pitting in iron pipes.
Temp - Rate of corrosion increases with incresing temperature
pH - Lower pH promotes corrosion.
DO - Oxygen promotes corrsion of ferrous metal forming tubercules and “red water”
TDS - Increases conductivity promoting electrochemicl corrosion
Bacteria - Bacteria in bioflim can create local changes in pH and DO.

39. Quality Issues 39 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Indicator - Langelier Saturation Index
LSI = pH - pHs
LSI > 0 Water is supersaturated with respect to calcium carbonate (CaCO3) and scale forming may occur.

40. Quality Issues 40 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Control
Make water less corrosive - pH adjustment most common (Typically 8.0 to 8.5).
Lay down protective lining on pipe wall - pH adjustment or Phosphate addition
Replace pipe with pipe less prone to corrosion.

41. Quality Issues 41 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Growth of Biofilms

42. Quality Issues 42 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Growth of Biofilms
Promotion
Growth depends on nutrient avalability (TOC)
High temperatures (>15oC) promote greater bacterial activity
Corroded pipes support film development
Low disinfecion residual
Low / stagnant flow

43. Quality Issues 43 Loss of Disinfection Residual
Growth of Disinfection By-products
Corrosion / dissolution
Growth of Biofilms
Reduction
Reduce nutrient avalability during treatment (reduce TOC)
Optimise disinfectant dosage / booster chlorination
Flushing
Corrosion control
Mains rehabilitation or replacement

44. Quality Issues 44 Loss of Disinfection Residual
Growth of Dinisfection By-products
Corrosion / dissolution
Growth of Biofilms
Cross connections and backflow

45. Quality Issues 45 Backsiphoning Loss of Disinfection Residual
Backflow when pressure in main drops (e.g. Surge, excessive flows, pipe bursts, flushing)
Backpressure
Backflow when pressure on contamonation side increases (e.g. pressurised heating/cooling systems, industrial systems.
Loss of Disinfection Residual
Growth of Dinisfection By-products
Corrosion / dissolution
Growth of Biofilms
Cross connections and backflow

46. Quality Issues 46 Loss of Disinfection Residual
Growth of Dinisfection By-products
Corrosion / dissolution
Growth of Biofilms
Cross connections and backflow
Stagnation – Dead Ends

47. Quality Issues 47 Loss of Disinfection Residual
Growth of Dinisfection By-products
Corrosion / dissolution
Growth of Biofilms
Cross connections and backflow
Stagnation – Dead Ends
Milky Water

48. Water Distribution Network Management and Leakage Control
Water Conservation 48
Water Distribution Network Management and Leakage Control

49. Water Distribution Network Management and Leakage Control
Water Conservation 49
Water Distribution Network Management and Leakage Control
Passive V’s Active

50. Water Conservation 50 Stage Element Central Funding Level Stage 1
Implementation of Water Management Systems
100%
(records 90%)
Stage 2
Active Leakage Control
100% limited
Stage 3
Rehabilitation
90%
Strategic Plans

51. Dublin Regional Water Conservation Project51
Dublin Regional Water Conservation Project
Total Savings 7.9 Ml/day
Pipe Rehabilitation Ml/day
Pressure Management Ml/day
DMA Optimisation/Metering Ml/day

52. Asset Data Water Conservation 52 Examples of Raw Data Held
Customer demand (billing information)
Customer complaints
Customer meter locations
Customer surveys
Demand surveys
Facilities failures
Flow and pressure measurements
Inspectors' site reports
Mains and facilities record drawings
Measured leakage and other non revenue
water uses and wastage
Meter maintenance/audits
Number of shut valves and operations
Network maintenance reports
Network performance by location
Records of repairs and rehabilitation
Pipe sampling (e.g. cut outs)
Staff training records
Water quality samples by location
Systems and processes used to collate and interpolate data
Asset data support
Burst records/deterioration models
District Meter Area monitoring
Distribution 0peration Maintenance Strategies
Emergency plans
Geographic Information Systems
Health & Safety records
Hydraulic, surge and water quality modelling
Information and models from other utilities
Job scheduling
Leak management

53. Water Conservation 53
Asset Data
2 + 2 = 4
5 + 3 = 8
x + y = ?

54. Unaccounted For Water 54 UFW = Water produced – Water Consumed
Made up of:-
Leakage
Incorrect meter readings
Illegal connections
Illegal or unknown use
Waste of water
Taps left open
Household losses
Bad plumbing
Tanks over flowing

55. Unaccounted For Water 55 Scheme A Scenario 1: Scenario 2: Scenario 3:
Scenario 2:
Scenario 3:
20 km of mains
Reduce UFW by half
New Large Non-Domestic Usage
1000 properties
AFW
200
m3/day
800
UFW
400
Into Supply
1,000
600
1,600
UFW Expressions 80 % 67 50 33
l/conn/hr 17
1,667
l/km/hr
833
Scheme A
Scenario 1:
20 km of mains
1000 properties
AFW
200
m3/day
UFW
800
Into Supply
1,000
UFW Expressions 80 % 33
l/conn/hr
1,667
l/km/hr
Scenario 3:
New Large Non-Domestic Usage
800
m3/day
1,600 50 % 33
l/conn/hr
1,667
l/km/hr
Scenario 2:
Reduce UFW by half
200
m3/day
400
600 67 % 17
l/conn/hr
833
l/km/hr

56. Leakage 56
56 |

57. Leakage 57
57 |

58. Leakage 58
58 |

59. Leakage 59
59 |

60. Leakage 60
60 |

61. Leakage 61
Leakage Control

62. Target Leakage (m3/km/d)62
Economic Level of Leakage (ELL):-
Typical SRELL
400
BLL
350
300
ELL
Value of water lost
250
ALC Costs
Total Costs
200
Euro NPV ('000)
150
100 50 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Target Leakage (m3/km/d)

63. Rehabilitation 63

64. Rehabilitation 64
Lead Common Services

65. Rehabilitation 65
Lead Common Services

66. Replacing Lead Common Services
Rehabilitation 66
Replacing Lead Common Services

67. Good data is key to sound investment decisions
Key Message 67
Good data is key to sound investment decisions
It is more cost effective to actively manage than to passively manage
Need to manage Water Quality risks associated with the distribution network.

68. 68
Thank You
Q’s