If you don’t set goals and have a 10-year plan and strategy, you’re just treading water. Budgets are great. But numbers aren’t enough. You have to set goals.”
So says Herbert Etheridge, manager of maintenance and construction for the Clayton County Water Authority (CCWA), based in Morrow, Ga. With the purchase of the Jonesboro and Forest Park municipal systems within its boundaries in 1994, Clayton County became one of the nation’s largest agencies responsible for all water mains, sewer mains and storm drains within county boundaries.
The acquisition of these two systems, the oldest in the county, brought numerous maintenance issues along with potential revenues. Maintenance and management of a water distribution and wastewater and stormwater collection system of this magnitude takes a strategy.
Clayton County has carefully chosen its plan of attack. Its programs include a trenchless pipe cleaning and lining program that saves substantial dollars and limits the disruption caused by open-trench line repair; a comprehensive replacement program for old and troublesome galvanized steel mains and service lines, and a leak detection program that returns $4 in water savings for every dollar invested. The approach is so successful that the county has won numerous industry awards and has become a model for other agencies.
Rehabilitate and save
When CCWA took over for the Jonesboro and Forest Park water systems, managers knew they faced aging lines that couldn’t be ignored for long. The bulk of both systems had been built before 1950 and contained numerous unlined cast-iron mains, many heavily tuberculated.
When CCWA crews needed to change the flow direction for fire protection, hydrant maintenance flushing, or emergency pumping, the mineral buildup would dislodge and discolor the water. Sometimes taste was affected. Although it was safe to drink, customers did not find the water pleasing. The authority also found that the buildup could affect flow and pressure.
At a program conducted by the Georgia Association of Water Professionals, Etheridge observed other distribution systems through-out the state that were being considered for the annual Distribution System of the Year award. During a stop in Macon, Ga., he saw a contractor cleaning and relining mains.
CCWA had a number of mains in need of rehabilitation, or of replacement at costs averaging $55 per foot, including restoration costs. After seeing the cleaning and lining process, Etheridge found that it would work for Clayton County. Better still, it would cost roughly $18 per foot and would limit disruption to customers. There was little doubt about how to proceed.
The cleaning and lining process starts with a thorough scraping of the pipe. Contractor J. Fletcher Creamer & Son Inc. uses a proprietary, self-built cleaning device made of spring-loaded steel. The unit consists of a series of heads with bolted-on blades that is winched or hydraulically pushed through the line.
While the scraper proceeds, water is introduced behind it to flush the debris and ease the device’s movement. The cleaning crew can determine by sight when the line is thoroughly clean and ready for lining.
“At the beginning of the process, the water coming from the exit point is as black as crude oil,” says Cliff Padgett, area manager for the contractor. “We continue the scraping process until we see completely clear water running out. In most cases, our scraper does the job in one pass.”
After the main is clean, a very dense Type II Portland cement mortar made of equal parts of sand and cement is applied. The mortar blend is a formula chosen for its particular sand gradation and pumpability. The mortar is pumped in and applied using another piece of self-designed equipment.
“Although there are some off-the-shelf tools for cleaning and lining, we have found through experience that the items we build ourselves give us better results for this type of work than anything currently available on the market,” says Padgett. The cleaning and lining process for an average city block can be completed within one day after the preparation work of establishing temporary services for area property owners.
Most of the 58,000 feet of pipe CCWA has cleaned and lined is 6- to 8-inch mains. The process has brought multiple benefits. “A pipe that should be 6 inches often has only a 3- or 4-inch opening because of the buildup,” Etheridge says.
“The cleaning and lining process not only addresses the discoloration caused by the buildup but also increases our available flow for firefighting by 350 to 900 gallons per minute and pumps up our pressure from 30 psi to 45 psi. We haven’t needed to upsize, as this process gives us back the full diameter function of our pipes.”
Replacing small lines
The CCWA system also includes 2-inch galvanized mains dating as far back as 1955, primarily in smaller streets and cul-de-sacs. Each such line serves eight to 10 homes. The galvanized pipes are a maintenance issue because of leaks and diminished flow.
“The big difference between the cast-iron and galvanized steel mains is rust,” Etheridge says. “Like cast iron, steel will accumulate the mineral buildup, but it will also degrade through from the outside from rust, and so it will develop leaks.”
Here, cleaning and relining is not an option, and an estimated 200,000 feet of steel pipe needs replacing. Always proactive, CCWA has already replaced 45,000 feet with lined cast-iron pipe and will replace the balance in the next 10 to 12 years.
Another problem is with the system’s galvanized steel service lines. Here, issues are most common when a main is located on the east side of a road with meters on the west. The longer pipes have vulnerable connection points, which can give way, causing surface leaks.
To address these lines, the authority 16 years ago began replacing all galvanized steel service lines with copper in entire subdivisions. To date, almost 95 percent of such lines have been replaced, and service calls and street flooding have been reduced.
Detecting water losses
In 2000, nearly 20 percent of the authority’s water was unaccounted for. At the time, the American Water Works Association (AWWA) acceptable standard was 15 percent loss for an average size system. To correct the problem, CCWA launched a mobile leak detection program and a permanent leak detection program.
For its first step, the authority purchased digital leak detection equipment from Flow Metrix Inc. and hired one foreman and two technicians to use it. Each day the crew goes to work, aiming eventually to evaluate and track the entire distribution system.
The Flow Metrix Inc. system collects digital information that can be downloaded into system maps in the ArcView GIS from ESRI and a Cityworks work order system from Azteca Systems Inc.
With this program, CCWA finds leaks before they surface. An AWWA study has shown that without a proactive detection program, the average leak may persist for as long as two years before it becomes visible on the surface. When CCWA discovers a leak, it is measured and immediately repaired. Since the start of the leak detection program, the crew has been through the entire system twice and has found 360 leaks that were not surfacing.
“When we measure a leak, we assume it would have leaked one more year before it was discovered or surfaced, which is conservative based on the AWWA report,” Etheridge says. “If all of the leaks we have found to date had gone one more year, we would have lost 4.6 billion gallons of water at a production cost of $3.2 million. For the $800,000 we’ve spent over the last seven years on this program, we’ve recovered more than $3 million. We save $4 for every dollar we invest, which isn’t a bad return.”
The second phase for capturing lost water is the installation of a permanent leak detection system from Flow Metrix that attaches to water meters. The devices will be placed in specified sections of the system at roughly 500-foot intervals. As the meters are read, they will also analyze and pinpoint leaks. The data will be downloaded daily into the Cityworks work order system so that repairs can be scheduled. CCWA has procured 10,000 leak detectors for 2008 installation and plans to add more each year until the entire system is equipped.
To date, the leak detection initiatives have helped CCWA reduce its lost water to 12 percent. The goal is to reduce it to 10 percent or less. This work has gained the attention of the Metro North Georgia Water Planning District, which uses the Clayton County program as a model for other agencies.
“As a requirement for licensing renewal, water distribution companies are now required to establish a leak detection program,” Etheridge says. “So the first call those folks make is to us to come by here and see how we set up our program and how we run it daily.”
Setting an example
Strategic planning and progressive rehabilitation, replacement and leak detection programs have earned CCWA the Georgia Association of Water Professionals highest honor, Water Distribution System of the Year for Large Systems, in 2003, 2005 and 2007.
The authority might have won the award more often if not for a rule that says the winner must “sit out” for the next year. “Everyone that wants to win the award knows what they’re shooting for; they want to be better than we are,” says Etheridge. “It’s a nice position to be in, but it does put a little pressure on you when you’re in the running.”
Planning and strategy have been keys in CCWA’s management of its massive system but Etheridge is quick to point out that nothing happens without the employees, management team and board of directors. “Our success, more than anything comes from our teamwork,” he says.
“Our board and management team doesn’t just come to the office and simply vote on what we ask for. They are involved. They look at programs, go to conferences, and visit with our crews in the field. This gives them the confidence in us that we need to operate successfully.”
