Jennifer Baca and Chris Lopez love a challenge, and it has taken them far. From temporary laborer, to senior operator in charge of laboratory operations, Baca has excelled at every turn. Lopez, also a senior operator, began in collections, then moved to wastewater operations.

While Baca’s challenges have included learning about wastewater laboratory operation and compliance testing and reporting, Lopez had to learn to operate a trickling filter and an activated sludge plant. Both are also helping start up a composting operation.

They work for the Los Alamos County (N.M.) Department of Public Utilities, which operates a trickling filter treatment plant (built in 1965) in the town of White Rock, and an activated sludge plant (built in 2007) in the City of Los Alamos.

Their success comes from determination, a strong work ethic and the support of their mentors. Both received 2012 Outstanding Operator of the Year awards from the New Mexico Water and Wastewater Association for their roles.

Rapid advancement

Baca started in 2005 at a now-decommissioned trickling filter plant in Los Alamos, doing grounds work and cleaning. She moved to full-time work eight months later. “I started learning about maintenance and how the operations process worked, and I found it more interesting,” she says. Moving up through the ranks, she earned more advanced wastewater certifications.

In mid-2007, she took over the lab. “The lab technician left, but not before he taught me the basics of lab work,” Baca says. “My supervisor continued the instruction, and I read up on the more difficult lab procedures on my own.” When a new activated sludge plant replaced the trickling filter plant later that year, Baca moved the lab operation there.

She learned to operate the activated sludge plant and was promoted to senior operator after earning her Level 4 wastewater certification in 2011. She cites Lopez as her primary mentor: “Chris taught me a lot over the years, and is always willing to share his knowledge.”

Lopez started his career in 1992 at the wastewater treatment plant in Santa Fe, working in collection system maintenance. He transferred to the Los Alamos trickling filter plant in 2002 and there learned about treatment processes and equipment maintenance. A Level 2 wastewater operator at the time, he earned Level 3 and 4 wastewater, Level 3 wastewater laboratory technician, Level 2 water operator, and compost facility operator certifications.

When the activated sludge plant came online, co-workers trained him on that process and on pumps, motors and electrical equipment maintenance. “My mentors are Santiago Martinez, my supervisor, and Jeff Ayers, plant superintendent,” says Lopez. “There was a lot of hands-on training.”

Running two plants

Today, Baca and Lopez work closely together at the White Rock trickling filter and Los Alamos activated sludge plants. “I work Monday through Friday in the lab and help out with operations when needed,” says Baca. “I also rotate on weekends with the other two senior operators.” Besides Baca and Lopez, the department team includes:

• Roland Dixon, senior operator, 16 years
• Ellis Nevarez Jr., operator, five years
• Marcos Ocanas, operator, one month
• Jeremy Martinez, apprentice I, two years
• Larry Naranjo, apprentice II, two years

All operators divide their time between the two plants, which are 6 miles apart.

The trickling filter plant (0.8 mgd design, 0.3 mgd average) serves 6,000 residents of White Rock. Two parallel treatment trains each include a grit settling channel, a primary clarifier, a cobble rock media trickling filter and a secondary clarifier. Flow is combined at a serpentine chlorine contact chamber, and the effluent is discharged to the Rio Grande or sent to reuse.

Reuse water flows to a lined holding pond for use on ball fields and in town parks. Effluent for discharge is dechlorinated and the flow is measured with a Parshall flume staff gauge and ultrasonic totalizing meter (Evoqua Water Technologies). The primary sludge is hauled to the Los Alamos plant’s headworks and added to that plant’s biosolids for composting.

The activated sludge plant (1.4 mgd design, 0.9 mgd average) serves 12,000 residents of Los Alamos. After screening and grit removal, influent is sent to an anoxic selector basin, then to two extended aeration basins equipped with fine-bubble disc diffusers (Sanitaire). The flow passes through two secondary clarifiers and a UV disinfection system (TrojanUV). From there, it is either treated with a chlorine disinfection system (MIOX) and sent to a holding tank for reuse, or discharged to a neighboring wetland. Biosolids are treated in an aerobic digester (Ovivo) and dewatered on a belt filter press (Ovivo).

Up to 600,000 gpd of reclaim water can be sent to a holding tank for reuse in parks, sports fields and the municipal golf course. “All the water reuse occurs between March and September. The rest of the year we discharge to wetland,” says Lopez.

Both plants can pose challenges. “The trickling filter is an older plant, and although it is easier to operate, there are maintenance issues,” says Lopez. At the activated sludge plant, the belt press dewatering process with polymer addition can be challenging at times: “We have been trying different vendors for our polymer to see which ones work best.”

Always learning

Baca and Lopez spent a lot of time learning their areas of expertise. In the lab, Baca was challenged to perform all operational and regulatory sample testing, staying on top of reporting paperwork for state and federal permits, and equipment calibration. “Some lab machines are touchy, and one little thing can throw them off,” she says.

For Lopez, the main hurdle was learning the activated sludge process. He and the other operators received classroom and hands-on training from equipment vendors. Lopez also received hands-on training from superintendent Ayers, whose 25 years’ experience with activated sludge plants helped all the operators understand the new plant’s performance and limitations.

A typical day for Lopez includes inspecting belts and pumps, wasting sludge, monitoring and adjusting the process as necessary, working with composting, doing routine rounds, checking SCADA data and performing preventive maintenance.

Operational challenges include the wide daily and seasonal temperature variations of the high desert environment, which can dramatically affect treatment. “We operate a biological nitrification/denitrification process, so the bugs react differently to temperature changes,” Lopez says. “What works well in the warm summer months may not work at all in the coldest months. We have to be constantly monitoring and adjusting our process.”

Says Baca, “We have a total nitrogen limit of 10 mg/L. Every morning I run the ammonia nitrate test, and if it’s close to the limit, I tell the operators to adjust the airflow into the aeration basins.”

Better biosolids

Lopez and Baca have been learning a lot about solids processing and composting at the activated sludge plant. “We also composted the solids at the old trickling filter plant, but the whole process is different at the new plant, where we compost the solids with manure and wood chips to produce Class A biosolids,” says Lopez. “We produce more biosolids, and it contains much more water than at the old trickling filter plant.”

The first batch of Class A biosolids was distributed to county residents last May. Although Baca and Lopez are both certified in composting operations, Lopez does the bulk of the work for now. Once he has mastered the process, he will train the other operators. Baca mostly performs lab tests to document the process for state regulators.

Both operators found their awards gratifying. Nominated by Santiago Martinez, they didn’t know about the awards until they were asked to attend the ceremony. “We were both surprised and honored,” says Lopez. “They gave us each a plaque, and there was a banquet after the ceremony.”

Says Martinez, “Both Jennifer and Chris have shown strong initiative and dedication. When they see things that need to be done, they take it on without being told. If work is delaying their departure at the end of the day, they don’t complain but continue until the job is done.”

Baca and Lopez appreciate the plant operators’ team mentality. Says Baca, “We all have different years and levels of experience, and we all help each other out. Santiago is out there helping us, and so is Jeff [Ayers] when we need him.”

They also enjoy dealing with the public. Lopez observes, “We give a lot of plant tours to school groups, and it’s fun.” Baca leads tours of the lab, showing the kids the microorganisms and the difference between influent and effluent.

Lopez offers advice to would-be operators: “If you are interested in the environment, you can do a lot of good working in this field. Many people out there don’t care about the environment or don’t think about it, but it’s an important part of the job and another reason I like what I do.”