Covering The Territory

The Washington County Service Authority uses aggressive system upgrades and current technology to cut water losses and improve operating efficiency.
Covering The Territory
The Middle Fork Water Treatment Plant team includes, from left, Joe Baldwin, chief operator; Beverly Hall, Class 1 operator; Don Cole, water production manager; and Gary Vanhuss, compliance manager.

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The hilly terrain and rural character of Washington County in far southwest Virginia can be deceiving. Beneath the ground runs a 900-mile-long water distribution system, closely monitored with state-of-the art software and upgraded with new piping. The results are already saving the Washington County Service Authority (WCSA) and its customers both water and money.

Under the direction of general manager Robbie Cornett, the utility, based in Abingdon, is in Phase 2 of a three-phase project to replace miles of aging 2-inch galvanized pipe. It has also divided its 300-square-mile service area into a series of subdistricts to help monitor water usage more precisely and identify leaks and inefficiencies. At the same time, the utility has constructed a new raw water intake on the Holston River, nearly doubled the capacity of its water treatment plant, and replaced manual meter reading with radio-based reading technology.

“We figure the galvanized pipe was costing us as much as $1.4 million a year, and we’ve identified four areas that have been accounting for more than half our water losses,” says Cornett. Other benefits of the new programs include a 33 percent reduction in meter reading staff, an 11 percent increase in water and sewer revenue, and the elimination of all but two of the 12 substandard pumping stations the old system used.

Spread-out system

Washington County lies in the southwest corner of the state, where Virginia, Tennessee and North Carolina come together. “We’re closer to five other state capitals than we are to Richmond [Virginia’s capital],” says Cornett. It’s a rural area, dotted with small population centers like the towns of Abingdon, Glade Spring and Damascus.

“In utility circles, people are amazed that we only have 23 customers per mile of pipe,” Cornett says. Dramatic elevation changes require pressure reduction and pumping stations along the water distribution system. Raw water comes from several sources: the Holston River, two large springs in the Mill Creek and Taylors Valley communities and, until recently, a small well in Mendota that has been phased out in favor of purchased water.

On the river, the Middle Fork intake structure (rated at 6.6 mgd) and the South Fork intake (12 mgd, under construction at press time) supply river water to the Middle Fork Water Treatment Plant, which has just undergone a $26.8 million capacity expansion. “The two intakes give us redundancy, in case we need to take one down for maintenance, or for water-quality reasons,” says Cornett.

Sodium permanganate is added at both intakes, reducing the risk of disinfection byproducts. At the plant, the water is treated in a flocculation-sedimentation process, followed by filtration, disinfection and fluoridation. The recent expansion added tube settlers (Meurer Research) to the downstream end of the existing sedimentation basins to improve the quality of the water passing to further treatment. “The tube settlers do a good job of collecting floc,” says Cornett. “The coagulant that best suits our water is Delpac 20/20 by USALCO.”

Adsorption clarifiers (WesTech Engineering) were added to bring capacity from 6.6 mgd to 12 mgd. Water flows by gravity from the sedimentation basins, so an energy-efficient intermediate booster station has been added to lift the water to the adsorption clarifiers (see sidebar). Finally, four anthracite media filters were added, bringing the total to eight (seven by Severn Trent and one by Leopold, a Xylem Brand). The clearwell and the finished water pumping station were doubled in size. Chlorine (stored at the plant in one-ton gas cylinders) and fluoride are added as the treated water leaves the plant.

Peak performance

The new equipment went into operation early last summer, and all processes have been performing well. “Our water quality is as good as or better than we were achieving with the old process,” Cornett says. “We’re delivering exceptional water at this point.”

They certainly are. For the third straight year, though in the midst of a major renovation, the Middle Fork plant achieved the highest possible ranking (20 in the judging criteria) in operations excellence for water utilities from the Virginia Department of Health. The plant was one of 22 conventional plants out of 130 that received a gold award in 2012. That followed gold awards in 2010 and 2011.

The water from WCSA’s springs is naturally pristine and requires little treatment beyond precautionary disinfection. Reservation Spring produces about 900,000 gpd. Chlorine, stored in 50-pound cylinders, is added at the point where the water enters the distribution system.

“This is one of the few springs in Virginia that is not under the influence of surface water,” explains Cornett. “It’s very high quality. We use it for entering the various water tasting contests.” (WCSA finished fourth among 100 entries in the Berkeley Springs International Water Tasting Awards competition in 2004.)

The elevation of the spring eliminates the need for pumping: the water flows by gravity to a number of customers in one of the small communities WCSA serves. The other spring delivers 1.8 mgd and requires treatment, as regulators have declared it to be affected by surface water. A small membrane plant (Koch Membrane Systems), one of the first in Virginia, has been in operation since 1999. WCSA owns the plant with a neighboring utility and has received excellent water quality, although the facility is due for upgrading and replacement in five to six years.

Galvanized pipe issues

Improvements to the water management system have involved more than upgrades to the intake and treatment facilities. When Cornett joined the agency in the early 1990s, he was quick to recognize the harmful impact the 2-inch and smaller galvanized pipe was having on the system. “Forty percent of all our connections were served by the galvanized pipe,” he remembers. “We had numerous customer complaints about lack of water pressure or poor-quality water — even colored water that would ruin a load of clothes in a washing machine.”

Ultimately, the agency committed to addressing the issue. As a stopgap, small blow-off valves (Cla-Val) were installed so that operators didn’t have to go into the field to turn water on or off. The blow-offs allowed automatic flushing of the system at night so that customers would get the best-quality water when they started their day.

In addition, to deal with pressure drops, WCSA installed 12 booster pump stations along the lines. While these measures eliminated most complaints, WCSA undertook a full-scale study of the galvanized pipe issue, analyzing leaks and breaks and the overall impact on the utility, especially costs. According to the agency’s calculations, 86 percent of all system leaks and breaks could be traced to the galvanized piping. That figure was later validated in an independent review of the system by The Lane Group engineering consultants.

“It became obvious that we needed to become more aggressive than we’d been in the past in replacing this pipe,” Cornett says. “Much of it wouldn’t have been capable of providing service to anyone in another 10 years.”

The project unfolded in three phases. WCSA tackled the most difficult replacement areas first. Those included the towns of Abingdon and Glade Spring, along with areas near and next to the city of Bristol — populous areas where lines run under streets and private property. Using open-cut methods for the most part, workers removed the galvanized lines and replaced them — with PVC for smaller diameters and ductile iron for larger.

Phase 1 involved installation of about 30 miles (3 percent) of the system, not including service lines, which added 10 miles. The replaced pipe serves about 8 percent of WCSA customers. “The pipe removed from service wasn’t inventoried but may have been greater than the number of miles installed,” explains Cornett.

"In some cases, it was a matter of jumping taps from the old galvanized line to a new line that had been installed in recent years — the old galvanized line was just never abandoned. It was a major undertaking, but Phase 1 was completed at the end of 2012 and went well. It’s early, but we’re already seeing a decrease in leaks and breaks and improved water line production.” WCSA advertised for bids on Phase 2 last fall and hoped to seek bids on Phase 3 by the fall of 2014.

Embracing automation

WCSA improvements don’t stop at fixing pipes. Cornett and his team launched other programs to make the system more efficient and enhance customer value. Automation is one area. “A few years ago we realized that most of our water meters were 20 to 40 years old,” says Cornett. “We were reading them manually, and over a 300-square-mile area, it took six people two months to completely read the system. Also, many meters were not correctly sized for the application.”

Since then, WCSA has adopted a radio-read system and a meter calibration and validation program. “We were able to reduce our meter reading staff from six people to four, reassigning the other two to a different department,” says Cornett. The agency also regularly checks the larger meters for accuracy, randomly checks residential meters, and remains on alert for any meters reading zero usage for several consecutive months.

SCADA represents another enhancement. “In 1998, we had no SCADA system, so we began implementing one,” says Cornett. “Before, our pumps ran on timers set by the operators, and tank levels were determined by visual observation, twice a day. Some tanks ran dry, others overflowed. It was an inefficient and ineffective way to run a system.”

It took six years, but today WCSA is equipped with a fully operational SCADA system (GE Intelligent Platforms, integrated by Innovative Controls) that has eliminated tank level issues and helps identify where breaks have occurred in the system. That has helped reduce water losses, as has refurbishment or installation of 16 new pressure-reducing valves throughout the system to cope with elevation changes.

Loss control

WCSA was also invited to take part in a beta study of new AWWA water audit software, a result of Cornett’s participation on the association’s Water Loss Control Committee. “The software was free, and we now use it to track real and apparent water losses and monitor our improvement efforts,” Cornett says. “It has allowed us to test and validate the accuracy of our data.”

In another move to enhance efficiency and improve system data, WCSA subdivided its service area into 30 smaller district metered areas. Customers in these areas are coded so that the team can monitor water use more closely and compare water use versus sales. “We’re still validating data, but what we’ve found so far is that four of these smaller districts account for more than half our water loss,” Cornett says. Two are older parts of the system, and the other two are industrial parks.

When staff members looked more closely at the water usage patterns, they realized that the industrial areas had the biggest concentration of unmetered fire lines, and that as industries expanded, contractors had been inadvertently tying into fire lines for process water, dust control and other uses. That led the agency to use clamp-on meters to try to measure flows. “Our goal is to convey information about water use to our customers — such as the time of day, how much they’re using and why they should consider reconfiguring their plumbing,” Cornett says.

The water loss program has also led WCSA to monitor its own water usage and optimize where possible. “We installed meters at all 26 of our lift stations and at all our facilities including the treatment plant,” Cornett says. “We found we use about 3 million gallons a month on average, not including the blow-offs on the galvanized lines. It was an eye-opener!”

More Information

CLA-VAL - 949/722-4800 - www.cla-val.com

Cornell Pump Company - www.cornellpump.com

GE Intelligent Platforms - 800/433-2682 - www.ge-ip.com

Innovative Controls - 412/824-2264 - www.innovativecontrolsinc.com

Koch Membrane Systems - 888/677-5624 - www.kochmembrane.com

Leopold - a Xylem Brand - 704/409-9700 - www.fbleopold.com

Meurer Research, Inc. - 303/279-8431 - www.meurerresearch.com

Severn Trent Services - 866/646-9201 - www.severntrentservices.com

USALCO - 410/354-0100 - www.usalco.com

WesTech Engineering, Inc. - 801/265-1000 - www.westech-inc.com



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