Chance Of A Lifetime
By Ted J. Rulseh
Ken Reynolds welcomed a challenge and led his team through a transition from an aging conventional plant to a sophisticated membrane facility.
On one hand it wasn’t easy switching from an old, familiar conventional water treatment plant to brand-new technology. On the other hand, it was an opportunity that comes along perhaps once in a generation — an opportunity many operators never get.
So Ken Reynolds embraced the challenge with his team in the city of Alcoa, Tenn. He guided an energetic and relatively young staff in assuming control of a fully automated, SCADA-driven membrane filtration facility just across the street from the old plant. At the time it went online in 2007, it was the largest immersed membrane water plant east of the Mississippi River.
Equipped with ZeeWeed 500 hollow-fiber membrane systems (GE Water & Process Technologies), the plant has a 16 mgd design capacity and an average flow of 6 to 7 mgd. It consistently achieves 0.015 NTU turbidity from variable-quality water in the Little River, which flows out of the Great Smoky Mountains.
Reynolds, water treatment plant supervisor since 1997, worked with the city’s engineering consultants in reviewing options to replace the old facility, built in the 1920s and aging severely. He credits his team for a mostly smooth transition: “Our people were not intimidated by the technology. There was nobody old and set in their ways. They were all really open-minded and willing to learn the system.”
Reynolds, winner of a 2013 Operator Meritorious Service Award from the Kentucky/Tennessee Section AWWA, was born in Greenville, Tenn., but has lived in Alcoa since age 6. He earned a bachelor’s degree in biology in 1983 from Tennessee Technological University.
He went to work for the City of Alcoa about nine months after college as a meter reader, but with his eye on a career related to his schooling. It took 12 years before he landed an assistant operator position at the water plant. A year later he had his Grade IV (highest) water treatment license and moved into an operator’s role; another year later the plant supervisor retired and Reynolds replaced him.
He leads eight operators, all with Grade IV water treatment licenses, and four maintenance staff members who work out of the water plant but perform general maintenance for the city. The team members are:
- Senior operator: Paul Phillips (33 years with the plant)
- Lab manager/operator: Dorothy Rader (15)
- Operators: Phil Bull (35), T.J. Emory (10), Steve Harris (15), Lori Sweppenheiser (nine), Russell Whitehead (eight) and Mike McClurg (nine)
- Certified maintenance: Mike Jenkins, plumber (18); Dave Shannon (22) and James McCarter (15), electricians
- In addition, seven team members service the water distribution and wastewater collection systems, all holding at minimum Grade II distribution or collection licenses:
- Construction services supervisor: Mark Ross (27)
- Leadworker II: Randy Slagle (25), Danny Ogle (22) and Gary Neeley Jr. (11)
- Utility serviceworker II: Josh Rutledge (11)
- Utility serviceworker II: Kevin Ray (22)
- Equipment Operator II: Paul Monroe (15)
Alcoa (population 8,500) lies about 10 miles south of Knoxville in the foothills of Great Smoky Mountains National Park. The city’s water system serves about 24,000 people, including the Tuckaleechee Utility District and surrounding areas of Blount County.
The Little River provides generally high-quality source water, although its turbidity can increase from 5 NTU during dry weather to 100 to 200 NTU during rainfalls, as feeder streams and creeks pour in sediment.
While the old plant had treated that water reliably for years, the need for change became apparent early in Reynolds’ tenure as supervisor. “We had four old upflow clarifiers, two built in 1961 and 1963 and the others in 1972 and 1978,” Reynolds says. “We went through rehabilitation on the two newer ones, and from exposure to the water and chemicals, the metal in them was just about shot.
“We looked at what we could do by way of an upgrade, and it appeared that was going to be a nightmare, just throwing good money after bad. We had land available across the street, and we decided to build a new plant there. At the time, membrane technology was relatively new and somewhat expensive, but the price was coming down. By 2002, the cost was pretty comparable to building a new conventional plant.” So, with an eye toward getting ahead of new U.S. EPA rules and regulations on turbidity and disinfection byproducts, the city decided on membranes.
The switch to membrane technology eliminated the settling step from the treatment process. The raw water needs minimal treatment for pH or alkalinity. After coagulation using aluminum chlorohydrate (ACH), it goes straight to the hollow-fiber filters with nominal 0.04-micron pore size, forming a positive barrier to solids and pathogens. All told, there are 1,344 filter modules in six tanks with some 3.9 million fibers totaling 27.9 million feet.
After filtration, the water is disinfected using sodium hypochlorite generated on site using a ClorTec system (Severn Trent Services), fluoridated and sent to a clearwell. It is then pumped to storage facilities that include two 6-million-gallon reservoirs, three standpipes totaling 1.45 million gallons, and a 1.5-million-gallon elevated tank. Some 245 miles of distribution and transmission mains deliver water to customers.
“We received good training from the membrane vendor, but a lot of the training was on the job, after the fact. It’s very different to read about it than to actually put your hands on it and then work the bugs out of all the equipment, computers, controls.”
One early challenge the team took on was replacing alum coagulant with ACH. “We started with alum and acid with enhanced coagulation, and it worked fine in summer, but not so great in winter,” Reynolds recalls.
“Alum doesn’t work well in cold, clear water. And soon after we started, the price of sulfuric acid went sky high. One month our chemical bill was close to $30,000. In addition, because we dropped the pH to get the alum to work, we had to feed that much more caustic on the back side to raise it back up. We went to ACH about five years ago, and it cured a lot of the problem. Our chemical bill is now about $6,000 a month.”
Working with the SCADA integrators (MR Systems) was also challenging. Never having worked with SCADA before, staff members had trouble telling the integrators what they wanted the system to do. “We had to depend on them to guide us and hold our hand somewhat,” says Reynolds. “After we gained experience with it, we were better able to tell them we wanted it to do this or that.”
Pleased with Automation
The SCADA system and telemetry have enhanced control over the water system, and over 18 wastewater lift stations. Telemetry monitors water reservoir and water tank levels. “With the SCADA system we’re able to set a certain level at the reservoirs,” says Reynolds. “If we set the level at a reservoir at 26 feet and demand through the day causes that level to drop, the system can signal the intake pumps to ramp up.”
The low-service and high-service pumps are equipped with variable-speed drives. Operators still set flow rates manually, continuing a practice from the old plant. “It keeps the operators a little more engaged in what’s going on,” says Reynolds. Operators also monitor stream gauges that detect source water turbidity and optimize the process by adjusting chemical doses as necessary.
So far the filters have handled source water variations with no impact on finished water quality, Reynolds reports. In fact, the water quality was good enough to win a 2013 Best Tasting Tap Water award from Kentucky/Tennessee AWWA and qualify to compete at the AWWA national conference in Boston in June 2014.
Operators stay abreast of developments in the water industry by completing continuing education requirements for their Grade IV licenses. Reynolds also encourages them to obtain distribution licenses. City officials support continuing education by sharing the cost and allowing team members time off for training.
“We try to attend as many local classes as we can that are no cost,” says Reynolds. “The State of Tennessee, like everybody else, is cutting back on free training. Most training sessions now cost about $125 to $150 a day, and with nine people, some of whom have multiple licenses, that could get pretty expensive.
“We attend meetings of the Tennessee Association of Utility Districts, which offer a couple of hours of education credit. We rotate who goes to the Kentucky-Tennessee AWWA annual meeting.”
Support from city officials, including competitive salaries and benefits, has helped keep an experienced Alcoa plant team intact. Operators are proud to show the new facility off to tour groups ranging from University of Tennessee engineering students to local elementary school classes.
While the plant has run smoothly for seven years, Reynolds notes that the time has come to start planning for membrane replacement and renewal of ancillary equipment. He faces the future with confidence: “We have an awfully good staff here. The operating staff and the maintenance team get along very well. In the end, it’s not about me — it’s about everybody else here. They keep the plant running. I’m just a spoke on the wheel.”View Article