
The sequencing batch reactor tanks (Aqua-Aerobic Systems) at the Moberly Wastewater Treatment Plant.
Ben Riles bends over a pot of steaming noodles in his kitchen. He stirs in some Cajun seasoning, then turns to another pot where’s he’s cooking up chicken, venison, scallops or shrimp, adding a spicy seasoning he orders online.
Finally he adds a dollop of heavy cream and some Parmesan cheese, and before long, he’s serving up his Cajun pasta to neighbors or family. “I got into cooking in my early 20s,” says Riles, chief operator of the Moberly (Missouri) Wastewater Treatment Plant.
“Having a large family required feeding a lot of mouths every night. I would eat something somewhere, or see something on TV that targeted foods from different parts of the world, and I’d say, ‘Man, I wish I could cook like that.’ I fix it to whatever moves your taste buds. I usually put my own twist on it until I get it right, which can be expensive at times! And I don’t worry about presentation; you just eat it.”
Riles is the winner of the 2018 Missouri Water Environment Association William D. Hatfield Award, and the association selected him as the 2014 Operator of the Year for small facilities. He’s a veteran of 17 years in the clean-water profession and just as passionate about his staff and his treatment operation as he is about his cooking, which includes barbequing and smoking meats in a smoker he built.
He’s responsible for Moberly’s 3.5 mgd sequencing batch reactor plant, the city’s combined sewer system, 14 lift stations and a staff of four operators. “He wears many hats,” says Mary Calcagno, director of Public Utilities. “He has an eye for details, is a problem-solver and works hard. He’s a vital asset to our program.”
Better technology
Draw a straight line from St. Louis to Kansas City and Moberly lies a smidgen north of the midpoint. Its wastewater treatment plant, which serves 12,000 customers across a 10-square-mile service area, was built in 1997 to replace two older-technology treatment plants.
The collections system consists of 87 miles of combined sanitary and storm sewers, some sections dating to the late 1800s. Pipes range from 8 to 60 inches, and materials include brick and clay, cast iron, and concrete. “We still have some of the old brick arches in place and working,” Calcagno says.
The plant provides preliminary and primary treatment, followed by two dual-cell SBRs (Aqua-Aerobic Systems). Decanted effluent from the SBRs is disinfected in a UV system with aquaray 40 HO bulbs from SUEZ Water Technologies & Solutions. The treated water is discharged to a tributary to Coon Creek, which flows into Mark Twain Lake, an 18,600-acre body of water in nearby Mark Twain State Park.
Solids are aerobically digested in basins equipped with Tornado subsurface aerators (Fluence), thickened in storage basins and applied as Class B biosolids at about 2 to 3 percent solids on a farm field owned by the city. Supernatant drains by gravity and is returned to the plant for treatment.
Plant controls consist of Allen-Bradley PLCs (Rockwell Automation) and an older SCADA system, which Riles says is in need of upgrading. The plant received the Missouri Water Environment Association Small Wastewater System of the Year award in 2002 and 2003 and won the association’s biosolids management award for small facilities in 2012.
Up the chain
Riles grew up in Moberly and went to work in construction after high school. In 1999 he started working for the city, and in 2001 he joined the wastewater utility as a maintenance worker. He worked up through the ranks, obtained his required licenses and was named chief operator in 2007.
While he was surprised to receive the Hatfield award, Calcagno wasn’t. She’s quick to give Riles credit for his doggedness and hands-on approach: “He’s boots on the ground.”
Riles says there’s no typical day for him. “Normally, I’m up at 5 a.m., at the plant by 7 a.m. and off at 3:30 p.m. But then there are the 2 a.m. phone calls and going out and working in the rain and the weather. A lot of people don’t see behind the scenes. It’s just nice that someone recognizes that we get out and work hard at our job.”
When he does have time at home, Riles keeps busy. “I spend some time with my wife, and then it’s off to the shop,” he says. Riles owns a 100-acre farm, likes to hunt and fish and has a passion for making things. He made the smoker he uses to smoke ribs, pork, beef roast and other delicacies. And he enjoys building decks.
“I worked for a framing contractor before working for the city,” he says. “After regular work hours, we would earn extra income by building decks on the houses we just constructed. I’ve always enjoyed building just about anything.”
Hands-on style
That desire to make and fix things carries over into his management style. “We rotate our staff through four activities,” Riles says. “All our operators are familiar with all phases of our system. That means anybody can jump in and help. If somebody’s missing, we can fill in.”
The Moberly team includes wastewater operators Doug Farrow, Donald Gregory, Delmer Hulett and Ike Case. Combined, they have more than 40 years of experience in treatment plant operations and maintenance. They rotate through operating the laboratory, gathering and running samples, inspecting lift stations daily, taking care of utilities in the field, changing oil, maintaining pumps and other equipment and tag-teaming other activities.
One operator is on call each week, carrying a standby phone. Riles uses a whiteboard at the plant to identify the weekly assignments and post announcements and other key information. “We’ve all been together for many years,” Riles says, “so we know what’s up.”
Critical confidence
Critical to the operation’s success is Riles’ support for his staff and his confidence in them, according to Farrow, who has worked with Riles for 17 years. He credits Riles for giving the staff the freedom to complete projects on their own, without being overseen: “He empowers us and motivates us to broaden our horizons.”
He cites a recent day when a grit removal system in a lift station broke down: “Ben said, ‘Listen, you guys are experienced enough; go out and do what you do.’ If we’re not sure, then he takes the time to show us. He’s a good communicator. There isn’t anything he can’t do. I’ve been through the fires with him.”
When equipment fails and an outside contractor is needed, Riles often involves Moberly’s staff to save money. He contacts vendors to determine what parts are needed to complete the repair, then assesses the staff’s capability and what a contractor would charge: “Depending on the size of the job, we’ll pitch in alongside the contractor to cut cost.”
Recently, a sludge transfer pump failed. “Due to the size of the equipment, it was not an in-house job,” Riles says. However, by getting most of the disassembly done before the contractor arrived and then helping to reinstall the pump, Riles and his staff were able to cut a day’s time and expense off the replacement.
That’s a good example of Riles’ management style. “You learn by doing,” he says. Sort of like his cooking.
Managing stormwater
Moberly is one of only five wastewater systems in Missouri with combined sanitary and storm sewers, and there are no plans to change anytime soon. Mary Calcagno, director of Public Utilities and a former wastewater plant superintendent, says Moberly’s system handles wet-weather flows effectively and meets all permit requirements.
Two former lagoons located in the collections system at the combined sewer system outfalls have been converted to store wet-weather flows when they exceed the plant’s capacity of 5 mgd. A swirl concentrator with a storage basin serves as a third storm flow unit and can accelerate the separation of debris from the water.
Once a storm has passed, the system directs stored water back into the sewer system through a series of pipes, and the water is treated in the plant with the normal dry-weather flow. It can take three to four weeks to return all of the flow to the system, says Ben Riles, chief operator.
“During a heavy rain, our influent flow can go from 1 mgd to 5 mgd in just 2 1/2 hours,” he says. For occasions when the storm flow exceeds the storage basins’ capacity, Moberly maintains four outfalls that discharge to area bodies of water.
Calcagno says the plant averages about 12 overflows in a given year: “During an average rainfall year, we treat 86.6 percent of the wet-weather flow received in the combined sewer system with full secondary treatment including disinfection, during the recreation season. And 99.2 percent of the flow is treated to at least primary treatment standards.”