Leak Detection at C.C.W.A.

1
Leak Detection at C.C.W.A.
2
History of C.C.W.A.

• CCWA produces up to 39 million gallons a day
  of potable water. We have a potable water storage
  capacity of 35.6 million gallons stored in 10
  ground and 8 elevated tanks. We also own and
  maintain 5 raw water reservoirs that provide raw
  water to 3 water production facilities. CCWA
  serves a population of 260,000 people through a
  system of distribution mains 1,265 miles long.

3
Water Lines in Clayton County

• Size Total Footage
• 36 8,100
• 30 77,785
• 24 170,020
• 20 93,877
• 18 270
• 16 439,165
• 12 552,580
• 10 43,837
• 8 1,878,707
• 6 2,822,384
• 2 592,208
• 1 1,512
• ¾ 945

• Total footage in Clayton County is 6,681,087
• Total miles of Water Main in Clayton County is
  1,265
• Total footage surveyed in Clayton County is
  4,805,312
• Total miles surveyed in Clayton County is 910
• 72 of our water system has been surveyed

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Leak Detection at CCWA
The CCWA Board of Directors and Management
Team began searching for ways to decrease our
water loss. In March of 2000, Leak Detection was
implemented.
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Non-Revenue Water Loss

• October 2004
• Non-revenue water loss is at 11

• March 2000
• Non-revenue water loss was nearing 20
• Leak Detection program Initiated
• Meter Testing Program expanded and placed under
  direction of the Maintenance and Construction
  Department

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Meter Testing Repair
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Meter Accuracy
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Our Goal

• Our goal was to develop and maintain a
  comprehensive Leak Detection Program by surveying
  the entire Distribution System.

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Starting a Leak Detection Crew

• We investigated and demonstrated several types of
  Leak Detection Equipment.
• After identifying the type of system we needed,
  our request was approved by the Clayton County
  Water Authority Board of Directors.
• We then started a Leak Detection Crew consisting
  of two people.
• We also added a Repair Crew made up of four
  people dedicated to repairing leaks that were
  found by the Leak Detection Crew.

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Equipment Purchased

• The system we purchased is the Flow Metrix
  Digicorr 98which has been upgraded to Digicorr
  III
• Digital Correlating Loggers
• Digitized map information (The entire countys
  water system is in the Digicorr program)
• Digital Filters
• Leak Detection Equipment and Van cost was
  approximately 71,000.00

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The Digital Difference

• Flow Metrix was able to create digital images
  of both area maps and detailed street plans used
  by the Clayton County Water Authority.

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Getting Started

• Connect both Field Sensing Units (FSU) to the
  Water Distribution System.
• FSUs can be connected to meters, service lines,
  fire hydrants and valves.
• Just make sure the connection is good and solid.

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Programming the Computer

• 2. After everything is connected it is time to
  input the information in the computer.
• Enter the pipe material and diameter.
• Enter the distance between the sensors.
• Then your ready to start correlation.

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The Computer
Leak

• 3. Once the base and the FSU radios are linked,
  the correlation process will begin automatically.
• The peak that develops in the correlation
  function indicates a leak.
• It usually takes between 1-30 seconds for a peak
  to develop.

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Z-Corr Digital Correlating Logger
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Programming Z-Corr

• Pick an area for deployment
• Program and place loggers on the map and print
  work order
• Deploy

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Deploying Z-Corr

• Z-Corr is ideally deployed underground on a valve
  operating nut
• However, it can also be mounted on any water
  system fitting

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Picking up Z-Corr and Downloading Information

• Once you pick up Z-Corr, place units back in
  docking station and download information
• The computer automatically goes through all the
  loggers and finds possible correlations
• Once a correlation has been detected enter the
  distance between loggers, pipe length and pipe
  diameter
• The computer will then automatically give you a
  distance and location for the suspected leak

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Formula to Determine Rates of Leakage

• Formula for Circular Orifice Q
  30.394 x A x ?P
• Formula for Other Opening Q 22.796
  x A x ?P
• A Area of Opening in Square Inches
• P Pressure (PSI)
• Q Gallons Per Minute (GPM)
• Some commonly used square roots
• 55 7.4 60 7.7 65 8.1 70 8.4
  75 8.7 80 8.9
• 85 9.2 90 9.5 95 9.7 100 10.0
• Example 6 Main with 1/8 wide beam break at 80
  psi
• GPM 30.394 x (3.14 x 6 x 1.25) x ?80
• 30.394 x 2.35 x 8.94 638.5 gpm

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Leaks Discovered
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Program to Date

• Year Leaks Discovered Gallons Recovered
  Production Cost
• 2000 47
  735,445,800
  1,220,840.03
• 2001 48
  506,941,200
  927,702.40
• 2002 16
  134,810,700
  338,374.86
• 2003 48
  462,468,000 1,114,547.
  88
• 2004 26
  237,308,400
  688,194.36
• TOTALS March 2000
  October 2004
• 179 leaks discovered and repaired
• 2, 076, 974, 100 gallons
• 4, 289, 659. 53 in production cost saved

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Production per Customer

• In 1999 we served 61,200 water customers
  (including accounts served by the City of
  Riverdale) and were producing/purchasing 10.5
  billion gallons of potable water per year
  (171,568 gallons/customer/year).
• We currently serve 73,600 water customers
  and are producing/purchasing 9.9 billion gallons
  of potable water per year (134,510
  gallons/customer/year).
• This programs success equates to a decreased
  production requirement of 5.8 MGD. That un-needed
  production is equal to over 50 of the capacity
  of our Freeman Road Water Production Facility and
  will delay Plant Expansions by several years.

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Cost of Program

• Total expended to date including Initial
  Investment, Hardware/Software Upgrade, Salaries,
  and Operating Expenses is 472,922.00.
• Projected annual operating costs 96,229.00
• For every dollar expended we have recovered 9.07
  in Production savings.

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Leaks Found

• We found a total of 179 leaks
• 90 leaks on ¾ water service lines
• 12 leaks on 1 water service lines
• 50 leaks on 2 water mains
• 19 leaks on 6 water mains
• 5 leaks on 8 water mains
• 1 leak on 10 water mains
• 1 leak on 12 water mains
• 1 leak on 16 water mains

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Leaks Found
6 Beam Break 160 GPM
¾bypass on 8 Fire Line 30 GPM
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Leaks Found
6 Beam Break 508 GPM
¾ Galvanized Service Line 9 GPM
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Leaks Found
¾ Copper Service Line 9 GPM
6 A.C. Pipe Split 160 GPM
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Conclusion

• The purpose of this presentation was to
  provide an information resource supporting the
  development of a Leak Detection Program and
  demonstrating the new technologies and management
  concepts to cost effectively reduce leakage to
  minimize your water/monetary losses.
• Please call Jeff Jones, CCWA Leak Detection
  Foreman, at 770-960-3612 for more information.