Tim Wilkey started his work life as a welder. Now toward the end of it, he’s superintendent of the Wastewater Division in Iowa City, Iowa.

In between, he has been a wastewater operator, an educator and an engineering consultant doing extensive work overseas. “It’s been a real rewarding experience,” says Wilkey, winner of a 2019 William D. Hatfield Award from the Iowa Water Environment Association. “Forty-five years ago when I was working in a factory, I never thought I’d be doing this.”

Wilkey leads a team of 26 at the Iowa City Wastewater Treatment Plant (10.5 mgd design, 9 mgd average), a biological nutrient removal extended aeration facility that operates mainly in the modified Ludzack-Ettinger mode. He has held his present position for four years, but his clean-water career goes back to 1986.

Long trail

That’s when he gave up welding and went to technical college in Cedar Rapids, earning an Associate of Science degree in general studies and an Associate of Applied Science degree in water and wastewater treatment. Later he earned a bachelor’s degree (1994) and a master’s degree (2005) in civil and environmental engineering from the University of Iowa.

His first position after technical college was as an operator at the Glenbard Wastewater Authority in Glen Ellyn, Illinois. After eight months there, he moved back to Iowa to manage the wastewater treatment process at a pork processing facility.

“That was a very eye-opening experience,” Wilkey says. “It helped prepare me for some of the harder situations I ran into later in life. At that time, the meat industry was known for having issues with the regulatory community. It was up to the wastewater plant operator to advise them on how to become a more responsible party.”

After 3 1/2 years there, Wilkey moved on to Kirkwood Community College in Cedar Rapids and taught water and wastewater technology for two years. He then enrolled at the University of Iowa, got his bachelor’s degree and joined a small engineering firm. Two years later, it was on to Ottumwa for 5 1/2 years as wastewater facility superintendent.

Learnings from abroad

While studying for his master’s degree, he worked for another small consultancy and then joined the Stanley Consultants global engineering service. While there, he consulted on a variety of water and wastewater projects, working in the Middle East, Afghanistan, Egypt and Algeria. In Qatar he oversaw the startup for the SCADA system on a 175 mgd biological nutrient removal plant.

The experience overseas broadened his perspectives. “When you work outside the U.S., it opens you up to other cultures, how things are done and how other people react. As a result, I’d like to think I’m more deliberate in how I deal with certain situations.”

While in Qatar, he worked with engineers from Europe, South Africa, New Zealand, Australia and multiple countries in Asia. “We also lived amid the Arabic culture, which is different from what we have here in the states. So in dealing with all those different entities, sometimes I had to walk a delicate path in terms of getting the desired results from activities such as the commissioning of a wastewater treatment plant.”

Then in 2015, the superintendent’s position in Iowa City became available, and Wilkey grabbed it. He works within a 20-minute bicycle ride or a five-minute car ride from home.

The treatment plant has six influent pumps: three dry-pit submersibles (KSB) and three close-coupled centrifugals (Pentair - Fairbanks Nijhuis). After passing through half-inch bar screens (Vulcan Industries), the water is lifted to an influent channel with a gate that can divert wet-weather flows to a 19 million-gallon equalization basin. A PISTA grit chamber (Smith & Loveless) removes grit.  

After five primary clarifiers (Walker Process Equipment, A Div. of McNish Corp.), the water enters four aeration trains, each with 10 cells (four anoxic, three aerated, three more anoxic). “We get nitrate uptake at the beginning of the trains, and then we get the carbonaceous uptake and any remaining ammonia removal in the aerated portion,” Wilkey says. “In the final portion, we aim to remove remaining carbon material and push any organisms to uptake nitrates and pull their oxygen off that.”

Influent contains on average 4.0 mg/L phosphorus; final effluent typically contains less than 1 mg/L. “We extended the anoxic areas to get to less than 1.0 mg/L DO to enable the release of the phosphorus so that it gets taken up in the aerated portion,” Wilkey says. The flow then goes to six clarifiers and to UV disinfection (SUEZ Water Technologies & Solutions) before discharge to the Iowa River.

On the solids side, primary and thickened waste activated sludges go through two thermophilic and four mesophilic digesters, followed by three 2-meter belt presses (Charter Machine) that dewater the Class A material to about 20% solids for land application by a contractor. The digester complex has multiple heat exchangers (Alfa Laval), two boilers (Burnham Industrial), several hot-water recirculation pumps (Bell & Gossett, a Xylem brand), sludge transfer and WEMCO mixing pumps (Trillium Pumps USA SLC - WEMCO) and multiple Muffin Monster grinders (JWC Environmental).

Modern facility

The Iowa City plant was last upgraded in 2010, at which point a much older facility near the downtown was decommissioned and the site converted into a riverside park. 

The plant is staffed 10 hours a day, seven days a week. At other times, a robust alarm system calls out to an on-call maintenance person. Team members are encouraged to pursue higher licenses and receive time off for training and to sit for licensing exams.

Wilkey believes strongly in promoting from within. In fact, a number of leadership positions have been filled that way recently. They include Brad Herrig, senior maintenance worker; Steve Flake, assistant superintendent; Al Figueroa, senior treatment plant operator; and Jesse Eister, senior maintenance worker in collections. The team also includes:

• Samara Hayek, senior clerk
• Jeff Clayton, Jeff Tonn, Dan Keating and Andy Pierson, treatment plant operators 
• Maintenance operators Jim Bopp and James Holland; maintenance workers Jesse Kleopfer, Tim Robinson and Kyle Coleman; Shaun Daly, electronics technician; and Ryan Bennett, electrician
• Collections maintenance workers Brian Gaffey, John Wombacher, Tom Kacena, Gus Garcia and Josh DeWild; and Dillion Evertsen, GIS technician
• Aimee Hanson, lab chemist, and Jennifer Widmer, lab technician

The team’s experience and dedication have paid off during challenging times. Wilkey recalls an incident when team members stepped up on their own to handle an emergency. Wilkey and other plant leaders were at a WEFTEC conference in Chicago when a rake on a bar screen came loose and fell 25 feet to the bottom of the influent channel.

“The guys are pretty confident; they knew what to do,” Wilkey says. “They got the equipment locked out/tagged out, pulled the rake out and took it to the shop. By the time we came back, they had started to disassemble it. They had contacted the manufacturer and figured out what they needed to do. We had to wait on parts, but the rake was back in service within a month.” 

Upgrades awaiting

More challenges lie ahead for the Iowa City facility, most notably dealing with struvite. “Since we’ve gone to biological nutrient removal, struvite has become more of an issue,” Wilkey says. “When we clean the digesters, we find that it remains as a sandlike material in the bottom. But when we get a temperature drop in the storage tank, that’s where we see deposition on the pipes and the tank walls.

“We’ve started to put a ceramic­like coating on the insides of our plug valves to cut back on the struvite formation. We’ve gone to sacrificial piping on the jet mixers in the storage tank. We’re just starting to get struvite formation in the drip pans of the sludge presses.” As a long-term solution, the team is studying struvite nutrient recovery technologies to determine which is the most cost-effective.

A food-waste-to-energy project is also under study. “Recently, the city launched a greenhouse gas and climate change initiative, looking to reduce the city’s carbon footprint,” Wilkey says. “The wastewater treatment plant is the biggest user of electricity and natural gas. If we accept food waste, make gas out of it and put it back into the system for someone to use, then we’re not just helping the city, but we’re also helping a larger area in reducing the carbon footprint.”

If the food-waste-to-energy project goes forward, the increase in biogas production would enable the heating of buildings beyond the two already served by the biogas-fueled boilers. Combined heat and power is not in the picture because such a system could not compete on cost with the area’s low-priced utility electricity.

Staying active

Besides his Hatfield award, Wilkey has received a 2018 Harris F. Seidel Award from the Iowa Water Environment Association for education and training. As a member of the Iowa Water Pollution Control Association Biosolids Committee, he received a 1998 U.S. EPA award for Outstanding Efforts Toward Public Acceptance for the Beneficial Use of Municipal Wastewater Biosolids.

Outside of work, Wilkey enjoys bicycling, restoring a 1967 Ford Fairlane and tinkering with a 1977 BMW motorcycle. He’s also restoring a couple of old, discarded bicycles for grandkids.

He has no immediate plans to leave Iowa City: “As long as I can still do a good job, I’ll be here to help keep the city moving forward, keep the plant up to date and replace equipment as needed. I’ll probably stay four to five years, and after that I’ll see if I’m ready to retire. If not, I still maintain my Professional Engineer license, so I could always go back into consulting.

“I’ve been reflecting on my history, talking to old friends in the business and remembering back when — the interesting people we’ve met along the way, the interesting things we’ve done. It has been a great career. You work with a lot of really great people, and it’s rewarding work because you’re providing a service for people and a service for the environment.”

Welcome to the career

Tim Wilkey got his baptism into the clean-water profession after a just few months in his first job at the Glenbard Wastewater Authority in Glen Ellyn, Illinois.

“I was working third shift and transferring primary solids to the digester,” Wilkey recalls. “Apparently I didn’t have one valve open or another, because as soon as I kicked on the positive displacement pump, it blew the top off of a ball check valve, covering the inside of the room, and me, with primary solids.

“I got the pump stopped and got everything corrected and pumping down to the digester. So there I am, a new employee, frantically hosing off every inch of the inside of the room. I thought, ‘I’ll worry about myself later.’ I just wanted to get the mess cleaned up.

“So as I was frantically cleaning up the room, the door of the building swung open and there was my foreman, who was an old motorcycle rider. He looked at me, looked around the room, and then looked back at me and said, ‘You’re busy. I’ll check back with you later.’”

“I think everybody who’s ever been in this industry has a story like that, where when things go bad, they go bad in a big way. Everybody gets some on them. It’s part of the nature of the job.”