You won’t find many women senior wastewater operators today. You’ll find even fewer who operate a four-story, 200 wet-ton-per-day multiple- hearth furnace.

Yet, that’s part of the job for Michelle Tarantino of the Central Contra Costa Sanitary District (known as Central San) in Martinez, California, east of San Francisco. In just 11 years, she has risen from a position in the warehouse to senior operator. Today she rotates on the day shift in charge of the plant’s biosolids operation, including the furnace, as well as its primary, secondary and tertiary wastewater treatment processes.

Holder of a Grade 3 wastewater operator license, she is one of only two women among the 20 operators at Central San, yet she sees no specific barriers keeping women from the field: “As long as they’re willing to put in the time and are determined to succeed, the sky’s the limit for women.”

Team approach

Tarantino is part of a three-person crew, plus a supervisor. The team is organized so that one operator manages the solids handling process, which includes dissolved air flotation thickeners, dewatering centrifuges, the furnace, boilers, a cogeneration unit, biosolids cake pumps and odor control. 

The second person assists in solids handling, monitoring the entire biosolids system. The third operator oversees the wet end of the 35 mgd (average) treatment plant.

Central San is one of the last plants in California to operate a biosolids incinerator. It produces 14 tons of sterile ash per day that is recycled as a turf additive. The furnace is fired by natural gas and landfill gas. A waste-heat boiler produces steam to drive the aerator turbines in the secondary treatment process, as well as some smaller plant equipment.

Change of careers

Wastewater operations was not exactly on Tarantino’s career wish list. “I worked in the technology field before the dot-com crash and then was in interior and residential design when the housing market cratered in 2009,” she recalls. A friend thought she might have the right stuff for wastewater treatment and encouraged her to apply at Central San.

Having been laid off, anything looked good; she decided to give it a try: “Nothing grosses me out,” she says. “It was very different.” In her first job she managed parts as a materials coordinator, but within six months she joined the plant’s operator-in-training program, and achieved the necessary licenses to become a wastewater operator.

“I was already taking some of the courses the district was offering through local colleges, so that helped a lot,” she says. Over the years, she has worked her way up through the first, second and third levels to senior operator.

Taking the heat

The biosolids operation is complex and requires a delicate touch. It starts with the Sharples centrifuges (Alfa Laval), which must work properly to produce quality cake at a consistent rate for the cake pumps (Schwing Bioset) that deliver material to the furnace.

“Running the furnace is similar to being the conductor of an orchestra, keeping all the instruments coordinated while maintaining a pleasant atmosphere for the audience,” Tarantino says. “While the biosolids are being incinerated, there must be certain oxygen levels and temperatures maintained to optimize burning of the cake.

“I call it being a furnace whisperer, making subtle, calculated changes to gently move temperatures or oxygen in a direction for success. You can’t make too many changes to the burners or air ports too quickly or else you will be fighting yourself constantly for hours.” 

In addition, the waste heat boiler, two auxiliary boilers and the cogeneration unit (Solar Turbines) and its waste-heat boiler must be monitored for proper pressure and water and chemical levels. Other critical components include the wet scrubbers that clean particulate emissions and gases from the furnace exhaust, a carbide lime system that maintains proper pH in the sludge storage tank, and a conveying system that removes furnace ash.

“Oxygen, opacity, hearth temperature and solids loading levels are only a few of the parameters monitored as just a part of our Bay Area Air Quality Management District regulations (Title V permit),” Tarantino says.

Even more challenges lie ahead as the Central San plant expands and changes to deal with future issues. “We’re facing huge upgrades in the next 10 years,” Tarantino says. “Power swaps, getting new equipment up and running, and training staff and new people. We say it can take up to five years for operations to adjust to and master new equipment and processes. Changes are starting to kick in. Some of our equipment is nearing the end of its useful life.”

Roles for women

While managing the facilities and her own career, Tarantino is an advocate for women in the water professions. She believes it’s about not only acquainting women with the field, but also educating the general public about water and wastewater.

She thinks social media like Facebook and Twitter offer unique and effective ways for utilities to get their message out to young people in general and to women in particular.

“Some pages put out by individual plants are fantastic,” she says. “They feature pictures and stories of women at work in the field. They’re very helpful in spreading the word.”

Job fairs and industry conferences are other ways, although Tarantino thinks conferences and events more focused on the general public are better for recruiting women. “The other woman operator here and I have been involved in panel discussions about our jobs,” she says. “I think we’ve been successful in presenting the opportunities.”

Central San publishes a quarterly flyer to ratepayers, and it often features women in professional positions. Tarantino thinks that’s effective, too.

She admits that while physical tasks at wastewater treatment plants can be challenging for some women, there are many jobs in engineering, process control and administration that women could readily fill.

“Other than life issues like child care that need to be worked out, I don’t see any barriers for women in this field,” says Tarantino, who is married and the mother of two daughters. “I’m crossing my fingers that we’ll see more women operators. As we host tours by school groups and scout troops, I hope we present a positive impression instead of a scary place to work.”

She felt accepted by the Central San team right from the start; it was no big deal when she passed the test. That doesn’t surprise her supervisor, Frank Favalora. “She’s wonderful to work with,” he says. “She’s a real team player and thinks outside the box.”

Recently, Tarantino came up with a way to make up two batches of carbide lime at a time, instead of one. “She’ll see something and figure out a better way — quicker, easier, safer,” Favalora says. “She’s been on my crew ever since she became an operator, and she makes my job easier. You don’t have to tell her; she’s already on it. We’re lucky to have her.”

Zero waste

The feeling is mutual. “I feel great about working for this plant,” Tarantino says. “We have zero waste. We recycle every bit of biosolids as ash. We recycle energy and water for irrigation. I’m definitely sticking with this plant and this career.”

For 2018 she was named an Emerging Leader by the California Water Environment Association. In the write-up about her, she was quoted as saying: “I’m a big fan of John Wayne. You need true grit to be a woman in operations, but if you hold your own, keep growing and keep studying, there’s really no stopping you.”

Becoming a shift supervisor is in her sights, and Favalora believes she has the stuff to make it: “She has participated in the supervisory academy. She has the potential, for sure.”

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Creating value

The Central Contra Costa Sanitary District collects and provides wastewater, recycled water and household hazardous waste collection to nearly half a million people and some 3,000 businesses in a 145-square-mile service area east of San Francisco Bay.

Started up in 1946, the district’s wastewater treatment plant has an average daily flow of 35 mgd and design capacity of 200 mgd. The plant’s slogan, “Waste to Worth,” plays out in the production of energy and the recycling of water and biosolids.

Wastewater flows through 1,500 miles of sewers, mostly by gravity, to the plant. It undergoes primary and secondary treatment and UV disinfection (Ironbrook UV) before discharge through a 4-mile-long pipeline to Suisun Bay. Filters and disinfection units further treat about 600 million gallons of effluent per year for irrigation, industrial use and in-plant processes.

For 20 consecutive years, Central San has earned the Platinum Peak Performance Award from the National Association of Clean Water Agencies.