Leak Detection at C.C.W.A.

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.

Water Lines in Clayton County

Size Total Footage36” 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

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.

Non-Revenue Water Loss

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

October 2004

• Non-revenue water loss is at 11%

Meter Testing & Repair

YEARLY USAGE

TOTALS:

All 3" and larger meters (270) in our system have been repaired/replaced and tested.

644,650,185

16,740,00035,148,000

2,193,180,000.00

POTENTIAL NET GAINGALLONS

CLAYTON COUNTY WATER AUTHORITY3" - 10" METER TEST RECAP SHEETCOMPLETION OF INITIAL TESTING

GALLONS

$3,485,409.60

POTENTIAL NET GAINREVENUE

$265,434.00$66,379.21

$2,642,065.75

$5,280.80

$154,459.27$151,424.12

$62,343.34

MONTH

2,424,746,000.00 850,343,809

16,190,05264,740,000

5,058,0005,112,000

JUNEJULYAUGUST

1999 TOTALS

45,636,0003,524,0002,088,000

MARCHAPRILMAY

118,260,000

JANUARYFEBRUARY

37,672,992

15,205,692

160,62033,503,556

$658.54$137,364.57

36,932,7121,288,000

Meter AccuracyMeter Size 5/8" 3/4" 1" 1 1/2" 2" 3" 4" 6" 8" 10" Totals

Total Number of MetersStandard Register 38,871 446 582 296 160 17 8 8 2 1 40,391

ECR Register 26,660 589 685 375 479 573 8 134 15 29,518Total 65,531 1,035 1,267 671 639 590 16 142 17 1 69,909

Number of AMR Meters 9,516 343 369 198 231 40 12 56 3 10,768

Averaged Meter Accuracy

PD 99.10% 99.37% 97.20% 98.97% 98.99% 98.73%Turbo 99.78% 99.77% 101.50% 99.53% 99.57% 100.94% 100.18%

Compound 99.26% 98.01% 97.52% 99.00% 98.45%FireLine 99.82% 99.25% 99.82% 99.63%

Total 99.25%

Our Goal

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

Starting a Leak Detection Crew

1. We investigated and demonstrated several types of Leak Detection Equipment.

2. After identifying the type of system we needed, our request was approved by the Clayton County Water Authority Board of Directors.

3. We then started a Leak Detection Crew consisting of two people.

4. We also added a Repair Crew made up of four people dedicated to repairing leaks that were found by the Leak Detection Crew.

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 county’s water system is in the Digicorr program)

• Digital Filters

• Leak Detection Equipment and Van cost was approximately $71,000.00

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.

Getting Started

1. 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.

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.

The Computer

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.

Leak

Z-Corr Digital Correlating Logger

Programming Z-Corr

1. Pick an area for deployment

2. Program and place loggers on the map and print work order

3. Deploy

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

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

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

Leaks Discovered

SIZE FOOTAGE LEAKS GALLONS PER YEAR

¾” 98, 581. 1’ 90 391, 674, 800

1” 21, 251. 4’ 12 76, 211, 900

2” 224, 001. 8’ 50 245, 681, 000

6” 2, 165, 462. 5’ 19 1, 000, 742, 400

8” 1, 246, 862. 5’ 5 345, 844, 800

10” 50, 801. 5’ 1 4, 730, 400

12” 189, 550. 8’ 1 1, 576, 800

16” 547, 657. 4’ 1 10, 512, 000

20” 75, 547. 3’ 0 0

24” 185, 596. 1’ 0 0

30” 0 0 0

36” 0 0 0

TOTAL 4, 805, 312. 40 179 2, 076, 974, 100

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

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.

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.

• 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

Leaks Found

6” Beam Break = 160 GPM ¾”bypass on 8” Fire Line = 30

GPM

Leaks Found

6” Beam Break =508 GPM ¾” Galvanized Service Line = 9 GPM

Leaks Found

¾” Copper Service Line = 9 GPM 6” A.C. Pipe Split = 160 GPM

Leaks Found

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.