To Matt Jenkins, optimizing a wastewater treatment plant is a lot like tuning a guitar.

“You can never just tune one or two strings and expect the others to stay the same,” he says. “As the tension changes on the neck, the tone of each individual string will change. A plant is much the same. You change one thing and it affects five or six other things. You basically work in a circle until finally it all stabilizes.”

That’s what Jenkins did for the City of Ridgefield (Washington) Wastewater Treatment Plant. In his two years there as lead operator, Jenkins and his team enacted process improvements that led to reductions of:

• 28 percent in routine horsepower demand
• 35 percent in overall power consumption
• 50 percent in UV output needed to meet disinfection limits
• 40 percent in polymer use
• 25 percent in biosolids produced
• 33 percent in biosolids hauling demand.

Now, Jenkins is wastewater systems supervisor at the La Center Water Reclamation Facility, not far from Ridgefield in Washington’s southwest corner, just over the border from Portland, Oregon. There, he oversees a membrane bioreactor plant while refining his skills in supervision and administration. “I’m not so much competitive as committed to daily growth,” says Jenkins, winner of the 2016 Western Washington Plant Operator of the Year award from the Pacific Northwest Clean Water Association. “I want to be the best version of me, so I can continue to grow in this position and in my career.”

Career change

Jenkins was born in La Center, graduated from high school in Battle Ground, and earned an associate degree in social and behavioral science from Citrus College in Glendora, California, before spending two years at Portland State University on a football scholarship.

After that he went to work for Rentrak, a company that handled rental and distribution contracts between movie studios and video rental store chains. When the online world began to decimate brick-and-mortar video outlets, Jenkins decided to make a move. “I grew up working on farms,” he says. “I wanted physical labor, but I also wanted to use my mind.”

After exploring power, water and wastewater utilities, he landed with Veolia Water Technologies in 2008 as an operations and maintenance technician at the Westside treatment facility in Vancouver, Washington. There he moved up to maintenance technician II and later operator I, working mainly in solids processing and incineration. His colleagues were longtime employees Bill Machaud and Tom Warner: “They taught me everything I was willing to learn. They didn’t hold back.”

In 2010, Jenkins moved to La Center for an operator position that also enabled him to gain laboratory experience. At the time, the city was converting from a sequencing batch reactor to a 0.73 mgd (design) MBR plant; Jenkins was able to observe the commissioning. He worked up to lead operator, handled maintenance including in-house pump rebuilds that helped reduce costs, and worked on process control.

New opportunity

He made his biggest mark after joining the Ridgefield plant as chief operator in July 2015 and assuming responsible charge three months later. Ridgefield, a fast-growing city of 7,300, has a 0.7 mgd extended aeration plant with nitrification and UV disinfection, discharging to Lake River, an estuary of the Columbia River. BOD and TSS limits are 30 mg/L, and the ammonia limit is 1.4 mg/L (all monthly averages).

The plant had been struggling with process issues, including high energy costs and difficulty meeting the ammonia limit, among the strictest in the state. Jenkins, with operators Fred Crippen and Jim Strickler, pitched right in. “They were great operators who had a ton of institutional knowledge of the facility,” Jenkins says. “Fred had a strong skill set in maintenance, and Jim liked the biology — the sampling and process control. It made a really good balance. They had been with the city for about 20 years. They could have easily said, ‘Shut up, kid. We’ve always done it this way.’ Instead, they jumped on board.”

Early on, Jenkins noticed an issue with how the operators were sampling the secondary clarifier sludge blanket: “They were going down too quickly with the Sludge Judge. When that sampler hits the bottom, if it’s still filling, it’s sucking sludge, so you end up with false high readings. That in turn gives a false high reading for the total pounds in the system, and for all the process control numbers from there on out.

“We would overwaste, causing us to almost violate on the ammonia limit because we didn’t have enough biology on hand to treat the ammonia. To combat that, we turned up the return activated sludge and the air, which helped. But the plant would go through rapid swings.  

“We would have overaging and would have to waste out to combat that problem, and then it would get young again. As it overaged, the effluent TSS would go up, so we had to run two units of UV disinfection to meet the fecal coliform limits. The waste activated sludge TSS to the thickener would go from 10,000 mg/L up to 18,000 mg/L. You have to dose polymer to the highest common denominator, so part of the time we were dosing twice as much polymer as needed.”

Taking control

While the sludge blanket sampling wasn’t the only issue, it was significant, and correcting it helped set the plant on a course toward process optimization. As the plant started to stabilize, it became feasible to turn the aeration down. In addition, the team replaced obsolete dissolved oxygen probes and meters with Hach SC200 meters using LDO2 probes. That immediately yielded more accurate DO readings.

Another step was to refine blower operations. “We were running an open header on two blowers to the two aeration basins,” Jenkins says. “The blowers were responding to the DO level in only one basin, so the other was either over- or underaerated. It was never where it needed to be.

“We ended up revalving the blowers and tying into SCADA. We were then able to assign each individual blower to an individual basin, so the blowers could function independently to meet each basin’s demand. Once we did that, the basins stabilized immediately, and we were able to slowly back down the DO setpoint from about 4.0 mg/L to about 2.2 mg/L. The RAS rate had been about 120 percent, and we backed that down to about 50 percent. That stabilized the process.

“Once the WAS reached a stable number, we could reduce the polymer dose to the thickener. In addition, by that point, our effluent TSS was in the single digits, so we were able to take one UV bank offline and still be in single digits on our fecal counts. We also extended the anoxic zone, and that helped with alkalinity retention. Between that and the lower DO setpoint, we were able to reduce our sodium hydroxide dosing by about 40 percent.”

Another of the benefits of the process changes was improved control over microbe growth and lower sludge yield. That made it possible to take one of the plant’s two aerobic digesters and offline, reducing horsepower demand by 50 hp and saving significant energy.

Back to La Center

After 2.5 years at Ridgefield, Jenkins returned to La Center as wastewater systems supervisor in late 2017. “It has been an experience getting re-acquainted,” he says. The plant, designed by Ovivo USA, uses a pair of KUBOTA Membrane USA flat-plate MBRs. Effluent quality is excellent; BOD and TSS are consistently 1 mg/L or lower, and fecal coliform after closed-vessel UV disinfection is typically nondetect. Discharge is to the East Fork of the Lewis River.

Waste activated sludge passes through a rotary fan press (Prime Solution), where it is dewatered to 10 to 15 percent solids. It is batch-fed to a Fenton indirect thermal dryer (RDP Technologies), which dries it to 90 percent solids or higher. The resulting Class A Exceptional Quality material is supplied mainly to a tree farm as a soil additive.

Jenkins’ staff includes Bill Birdwell, operator III; and Jeremy Klinski, operator I/operator-in-training. “There’s not as much meat on the bone here as there was at Ridgefield for process control improvements, but there is some work to be done,” he says.

Physical space is a challenge on the plant site: “At some point, we will have to treat 3 mgd average with a 6 mgd peak on a 0.75-acre parcel. Everything we do, from the MBRs, to the rotary fan press, to the dryer, is designed around footprint. The neat thing is that this plant is immediately expandable to a 1.5 mgd average day and a 3 mgd peak day with minimal construction. We just need to drop MBRs into two more tanks that are already existing.”

Still learning

For his own development, Jenkins wants to become accomplished in asset management: “In our industry, it’s becoming more and more important to plan for the future — to be able to plan the life cycle of equipment and to budget accordingly. I’d like to implement that here. The guys have done an excellent job taking care of PMs and corrective maintenance, but I want us to be dialed in to the point where we do predictive maintenance.”

His long-term goal is to refine his skills as a supervisor and administrator. In that quest, he’ll adopt the same approach to learning that has served him well until now: “I have not met seasoned operators who won’t show you everything they know, as long as you’re open-minded and humble. That’s the key to the growth I’ve had in this industry. Always be willing to learn. That’s the main thing. And always be kind to others — or as my dad would say, ‘Don’t be a jerk.’ Those things seem to go a long way.”

A resource for learning

During his time at the Ridgefield (Washington) Wastewater Treatment Plant, Matt Jenkins found a valuable resource in the Discovery Clean Water Alliance. It’s a partnership of Clark County, which operates major wastewater treatment plants serving north Vancouver; the Clark Regional Wastewater District, which handles wastewater collection; and the cities of Ridgefield and Battle Ground.

“I ran a small Class 2 plant, but through the alliance, I had access to engineers and process control and instrumentation people through the alliance partner organizations,” Jenkins says. A key mentor was Tom Burns, who hired him for his first wastewater job with Veolia Water Technologies and ultimately became operations manager with the Clark Regional district.

Jenkins recalls that Burns supported him from the time he started at Veolia Water Technologies: “He was a project manager, running two huge facilities in Vancouver. He might as well have been the president of the United States at that point in my life. He called me into his office on my second day on the job and just talked to me, person to person. He gave me a lot of motivation and inspired me to do the things I’ve been able to do since then. In 2015, when I was hired at Ridgefield, he was on the interview panel. I got to spend the next two years working with him as part of the alliance. I owe him a lot.”

Today, Jenkins gives back by teaching classes in maintenance, process control and other topics at the Clackamas Community College Short School put on by the Oregon Water Education Foundation. He mainly instructs operators-in-training and Group I operators. “So many people out there want what this industry can offer, but they just don’t know it’s there or how to get to it,” he says. “I really enjoy giving them insight into who to talk to and where to go — helping them to succeed.”