No one can say that high-tech instruments are responsible for the award-winning performance of the two clean-water plants in Amarillo, Texas.

The 50 team members at the city’s River Road and Hollywood Road plants rely on their knowledge, their observations and manual adjustments to keep the facilities producing top-quality effluent.

Operators do rounds every two hours, monitoring key parameters like dissolved oxygen, chlorine content and total solids. They take grab samples and run laboratory analyses themselves, an approach that helps teach staffers the ins and outs of the entire treatment process, according to Jim Stover, wastewater treatment superintendent.

A software package (AllMax) helps both plant teams manage preventive maintenance, tracking work orders, repairs and work history on all processes, including parts and labor. Other than that, it’s operators’ skills that keep the activated sludge processes in constant balance and win Platinum Awards for perfect compliance year after year from the National Association of Clean Water Agencies.

The operators’ long years of experience are both a blessing and a concern: The city’s workforce is aging, and replacing them as they retire will be a significant challenge, notes Stover, who is responsible for both plants. “Nobody grew up wanting to be a wastewater treatment operator,” he says. “We all wanted to be president, or a lawyer, or a doctor.”

Similar processes 

Both River Road (16 mgd design) and Hollywood Road (12 mgd) use conventional activated sludge treatment, preceded by bar screens, grit chambers and primary clarifiers, and followed by gravity media filtration. 

At River Road, the two bar screens have motorized cog mechanisms that remove screenings and dump them to a conveyor. Two Detritor grit pumps (Ovivo) move grit to a Krebs cyclone separator (FLSmidth). Wastewater flows on to a set of four circular primary tanks, two 80 feet and two 70 feet in diameter. The secondary system consists of five rectangular aeration basins, each with fine-bubble aerators (Sanitaire – a Xylem Brand) fed by Roots blowers (GE Energy). The water is decanted in six 80-foot-diameter secondary clarifiers.

Effluent is disinfected with gaseous chlorine, dechlorinated with sulfur dioxide (Evoqua Water Technologies) and routed to a reservoir. From there, the water is pumped to the Xcel Energy Nichols Power Station, where it is treated further and used for cooling water makeup.

Effluent is discharged to the receiving stream (East Amarillo Creek) only for biomonitoring. When that occurs, the effluent passes through a multimedia gravity filter (Infilco Degremont) before chlorination-dechlorination.

At Hollywood Road, preliminary and primary treatment are the same as at River Road. The secondary system includes six rectangular aeration basins with fine-bubble diffusers, followed by clarifiers, a traveling bridge tertiary filter (Aqua-Aerobic Systems) and a Capital Controls chlorination-dechlorination system (Severn Trent Services). The plant discharges to tributaries of the Red River and to Tanglewood Lake. The primary clarifier outfalls are covered to contain odors. Kirk Paulhamus, assistant superintendent and plant manager of Hollywood Road, says his staff never uses a bleach-based odor control system because odors are simply not an issue. 

The plants’ biosolids trains are also similar. River Road uses dissolved air flotation and gravity thickening before feeding to thermophilic digestion, used because of its smaller footprint. The plant is equipped with two belt presses (Charter Machine Company). 

Hollywood Road uses mesophilic digestion. Dissolved air flotation thickens waste activated sludge and primary sludge is thickened in the clarifiers ahead of a pair of belt filter presses (Komline-Sanderson). The dewatered cake is landfilled. The cake averages 18 to 20 percent solids, and the annual volume is about 2,000 dry tons, according to Paulhamus.

At River Road, the belt filter presses are not used — about 20 million gallons a year of liquid biosolids are injected into a 110-acre farm field next to the treatment plant. It’s a matter of economics, according to Michael Brogdon, assistant superintendent, who manages that facility.

Award winners 

In 2013, the River Road plant received an NACWA Platinum Award for eight years of continuous compliance with its discharge permit, and the Hollywood Road facility received a Platinum Award for seven consecutive years of compliance. 

Platinum Awards recognize 100 percent compliance with NPDES permits over five consecutive years as a base, and then honor plants for additional consecutive years of compliance after that. Platinum status continues for each additional year of perfect compliance. In 2013, only 15 plants nationwide received the Platinum recognition for eight consecutive years of compliance, and 12 received Platinum recognition for seven consecutive years.

For Stover, it isn’t sufficient for the plants to operate “well enough.” He observes, “We operate the plants as best as they can be operated.” The data bears him out. At both plants, effluent CBOD averaged 2.1 mg/L and TSS 1.4 mg/L last year. Ammonia was reduced to about 0.4 mg/L. The high-quality effluent easily complies with Amarillo’s discharge permit.

“We’re very proud of our record,” says Stover. One reason for the outstanding performance is a cadre of veterans Stover supervises. At River Road, the key people are Brogdon and Michael Jesse, operations control supervisor. Their counterparts at the Hollywood Road plant are Paulhamus and Jorge Vasquez, operations control supervisor.

“They are our keys to success,” says Stover. “If there’s a problem, they identify it and resolve it. They are our go-to people.” The group also leads the city’s teaching and certification efforts, and some management team members are registered teachers for the Texas Water Utility Board.

Hands-on approach

Hands-on is the main method for training new employees, and that old-fashioned approach is also Amarillo’s choice for process operations. Stover prefers that his team members monitor and adjust plant processes by hand, instead of relying on automation and instrumentation.

“With activated sludge, we’re taking care of a life form, keeping it healthy 24 hours a day,” Stover says. “Even though the basins are built to be hydraulically equal, we need to adjust flows, return sludge and air. We do that manually — even our DOs — and we use our on-site laboratory to do the analyses. Each basin needs to be balanced. Treatment plants have a life of their own. There are always surprises.”

Stover and his team believe that the more operators perform the work themselves, the more they understand the process. Besides, he adds, automation costs money, and Amarillo is currently focused on improvements to its collections system infrastructure and replacing antiquated equipment at the treatment facilities.

Plant leaders are true believers in the hands-on approach, which enables operators to get fully familiar with the equipment. “We do rounds every two hours,” Brogdon says. “If a pump sounds different than it should, we can find the problem quicker.”

According to Paulhamus, nine operators staff the Hollywood Road plant around the clock. “They inspect all meters and take samples, which they analyze in the plant laboratory,” he says. All operators are trained in basic laboratory procedures. They write the results down and enter them into spreadsheets.

“We have a small SCADA system that monitors things like influent flow, but it doesn’t have any control features,” Paulhamus says. When new operators come on board, they spend the first month or two assigned to one of the veterans. “We believe in this approach to training and developing an understanding of how the plant works.”

Recruitment needs

The ongoing challenge is to recruit new operators to a department workforce where the average age is high among the 50 employees, split evenly between the two plants, 17 miles apart as the crow flies. Pending retirements make it essential to attract new talent.

Stover and his staff would like to be surprised by an increase in applications to work in wastewater treatment. “We used to have dozens to choose from,” says Stover, who has worked 32 years with Amarillo. “But these days we’re lucky to get three or four to apply when a position opens up. I’ve made suggestions that since most people won’t consider working in the wastewater field, we might need to pay wastewater treatment plant operators more than other city jobs, but that hasn’t been received well.”

Management staff members recruit in local schools. As an incentive to operators, the department pays for certification of those who sign on and advance up the ladder. Operators are promoted and receive pay raises each time they advance in certification. Maintenance personnel are on a similar program.

And the atmosphere at the plants is friendly and welcoming: “Whenever I’m at one of the sites, the operators holler ‘Hey, Mr. Stover,’ and we talk about the plant and their projects. Every holiday, we have a staff dinner at the plants. Everybody brings a home-cooked item. We call it food made with love.”

Nonetheless, recruitment remains at the top of the priority list: “We may have to do more. We can’t continue this way.”