Wastewater treatment is Rey Davila’s passion.

Recently retired, he loved his job as chief of solids operations at the South Mesquite Creek Regional Wastewater Treatment Plant. He’s committed to operator associations and the Water Environment Federation’s Operations Challenge.

And he’s so devoted to training that he has signed on with the local college to help train new operators to fill the positions left by those retiring. His local utility will need 30 to 40 new operators in the next two years.

“He’s very passionate and giving to others,” says Sharon Miller, P.E., regional operations engineer with the North Texas Municipal Water District in Mesquite, which operates the South Mesquite Creek plant. “You can see it in his mentorship of others. Rey is the first person to help if there’s a question. He’s great at explaining to the staff why we’re doing something. He gives the bigger picture.”

As for the challenges he has faced and the successes attained in 34 years in the wastewater profession, Davila says, “I love it. I basically dedicated my life to the wastewater industry, especially training. Train, train, train!”

From south of the border

Davila’s career began in Mexico, where he studied electrical engineering. After coming to the United States, he worked for three years on traffic signals for the city of Dallas, but he developed a curiosity for wastewater treatment. The city’s Central Wastewater Treatment Plant had openings only for operators, not electricians.

Undaunted, Davila signed on and earned his license, and the seeds were planted. He excelled at operations at the Central Plant, and later, as shift supervisor at the utility’s Southside Plant, he became a certified trainer with the city, teaching classes and taking part in internet training. He also became active in the Operations Challenge.

He sees that program as an outstanding training opportunity. “It’s a great tool,” he says. “It’s designed to train other operators, and it helps create more professionalism in the field, enabling operators to achieve their goals.”

Crossing border

He’s not just talking about the U.S. competition. In 2012, Davila represented the country at the International Operations Challenge in Argentina. “There were two of us from Texas and two from Los Angeles,” he recalls. “We had two days to get familiar with the equipment. I was the only one who spoke Spanish, so I could read the instructions.” It paid off, as his team finished in the top 10 against entrants from all over Argentina.

After taking early retirement from Dallas, Davila joined the North Texas Municipal Water District to head solids handling operations at the South Mesquite Creek plant, a regional 33 mgd facility.

The plant employs primary treatment followed by separate trains of conventional activated sludge and A2O biological nutrient removal. Traveling sand and disc filters (Kruger) polish the effluent, and a newly installed TrojanUV3000 system disinfects the flow before discharge to South Mesquite Creek.

Waste activated sludge is thickened to about 3% solids on gravity belt thickeners (Charter Machine Co.) and pumped to a blend tank; it is later pumped to BDP Industries belt filter presses for dewatering. The cake, at about 24% solids, is stored in 25- and 30-cubic-yard containers. Twelve to 16 truckloads per day are hauled to landfill in utility-owned trucks.

Davila managed a crew of nine: Zachary Jackson, solids lead operator; Joshua Deaver, Alex Verduzco, Maurice Moore and Adolfo Arriaga, operators; and Eddy Maupin, Rodney Bass, Robert Livingston and Robert Weishaupt, truck drivers.

Optimizing chemicals

One of his most recent challenges was optimizing the chemical feed process that promotes dewatering. “We were spending too much on polymers,” he says. Committed to reducing costs, he started calling colleagues and suppliers and jar-testing polymers. He used an outside laboratory to verify the results.

After paring the possibilities down to three candidates, Davila and his team decided on an emulsion polymer to replace the cationic polymer they had been using. The results were dramatic. The new polymer improved dewatering and saved money because less chemical dosing was required. Davila estimates annual savings of $500,000.

Miller worked on the project as well and lauds Davila’s efforts: “I worked with him on the conversion. Rey set up a protocol for testing with emulsion polymers. I helped him with a new pumping system.” Then they evaluated and created a skid-mounted system containing pumps, mixers, controls and piping. “We worked together, walking through the system and working with vendors.”

At first, they estimated a cost of $150,000 for new equipment, but then realized they only needed to change out the feed pumps (Watson-Marlow) at a cost of $9,000. Rick Painter, senior mechanic, designed new racks for the polymer totes to sit on. Miller observes, “If you have process questions, Rey is a great resource to call on.”

Source of advice

Davila’s work hasn’t gone unnoticed. He says his greatest career rewards include receiving the David Barber Competitive Spirit Award (2012) and Municipal Operator of the Year award (2015) from the Water Environment Association of Texas. Last year, he received the WEF William D. Hatfield Award, selected by the WEAT.

With such experience and recognition in his pocket, Davila is in a good position to offer advice to others in wastewater management. Treatment plants are like fingerprints, he says. “Every plant is different.” That means operators need to be ready to face unique challenges.

Besides solving the polymer issue at South Mesquite Creek, Davila faced challenges during his time at Dallas, as he and the staff learned to manage new acid-mode anaerobic digesters.

The answers often lie within the industry itself, Davila believes. He believes the WEF and WEAT represent decades of knowledge and expertise that operators and managers should take advantage of: “It’s a great industry and a huge network. Get involved. There are classes and workshops that will help you resolve issues and do your job better. It’s valuable training, and it will bring out the best in you.”

He also points to the support he has received from his upper management: “Mike Rickman, our deputy director; Jenna Covington, P.E., our assistant deputy director; and Jeremy Thompson, plant supervisor, have been very supportive. They’re strong leaders and form a great team.”

Actively retired

While Davila has retired from his operations position at South Mesquite Creek, he’s hardly sitting in a rocking chair. Instead, he has started working with Steve Rummel and Mike Helms of the district’s training team to establish a waterworks training program at Collin College for new operators, with funding support from a state grant.

The program involves classes and internships that students can use to learn about opportunities in wastewater and water operations. “This is hands-on training,” Davila says. “Students shadow operators. They experience lab work, process control and testing — how the industry works. Then they can decide what departments they are interested in and whether they want to stay with us or not. We already have four students hired for internships, and we’ve started our second group of classes.”

He’s teaching that course, but he’s also on the other side of the classroom, finishing his studies in environmental science. He will receive his associate degree in spring. “This is what I want to do right now,” he says. “I just plan to keep on going.”