Overcoming odds, engineer ensures gas flows to community
Women in engineering careers is a rarity. Women engineers who’ve earned a professional license, well, that’s almost unheard of.
Although women make up more than half of the college-educated workers across the U.S., their male counterparts greatly outnumber them in both the classroom and workforce when it comes to the science and engineering fields. One staggering figure from the Society of Women Engineers underscores this disparity: only 13% of engineers in the U.S. workforce are female. Even more staggering: Of the total number of licensed professional engineers, a mere 5% are women.
Christina Castilleja didn’t let the numbers deter her. Encouraged by her high school physics teacher and her grandfather, she earned a Bachelor of Science in mechanical engineering from the University of Texas at San Antonio. She went on to become a licensed professional engineer, while juggling a career and family.
Today, we shine the light on Christina, a Senior Engineer in CPS Energy’s Gas Solutions area, as we commemorate Natural Gas Utility Workers’ Day and we continue our Women’s History Month series.
Keep reading to learn more about Christina, her career and her personal experiences.
Us: Describe your role at CPS Energy.
Christina: I started in 2006 as a design engineer in Gas Solutions supporting customers and designing mains, services, meters and regulators for large customer projects.
I now serve as the primary gas system modeler. Using a special software application, I model the entire gas distribution system for CPS Energy – its distribution from once we receive it to getting it to our customers. This includes annual calibrations with real-time recorded natural gas pressure and flow data to ensure modeling accuracy.
My overall goal is system-wide natural gas reliability. I review and propose projects for areas of higher risk and growth.
Day to day, I assist in validating system support for all new gas system projects for Customer and Gas Engineering — working closely with designers and engineers to determine the best solution for gas supply to new and existing customers.

Us: Has being a female in a mostly male industry been challenging?
Christina: I welcome challenges in all their forms; it’s a part of what drives me. Working as an engineer for almost 15 years, I haven’t found that being female is a hurdle or impediment. I’ve been fortunate to have supportive and understanding management and never felt like I was being treated differently.
Funny enough, when I started, leadership in my area seemed to challenge all newcomers, male or female, basically to get an idea of how much they knew. I quickly overcame any doubt they may have had in my abilities, and they became a great resource. We continue to bounce ideas off one another and collaborate to find the best solutions for construction obstacles.
Us: How does your work bring value to our customers and community?
Christina: My recommendations directly impact customers and the community when it comes to natural gas system support and reliability. From the hydraulic analysis I perform to the preliminary cost estimates I run, my job is to ensure safe, reliable natural gas is provided year-round to our customers.
If there are difficulties or if additional improvements are needed to support the new customer load, I propose the most cost-effective solution to suit the customers’ needs. The shortest route isn’t always the most cost-effective even from a system analysis perspective.
Us: What has been the most rewarding aspect of your career with CPS Energy?
Christina: Mentoring opportunities through the SAFE (Student Assistance for Education) and Connecting the Dots programs. Mentoring high school students and seeing them through the program was an experience that gave me great pride.
I also was a Reading Buddy for four years, helping second graders improve their reading and comprehension skills.
And I mentor design engineers within the Gas System Engineering and Customer Design Engineering departments. I meet with and train engineers on the gas system model and general hydraulic analysis for their projects and other high-profile projects.
Us: What is the best advice you’ve ever received and what advice do you have for others?
Christina: My mentor in high school, Susan Mann, had such a positive outlook and was a true inspiration. She emphasized the importance of being a lifelong learner. I never reject a learning opportunity and love to share my expertise.
My advice to others: once a goal is defined, find your motivation and persevere. Goals can change no matter how big or small. If it truly means something to you, don’t allow obstacles to deter or sidetrack you.
Us: In 3 words or less, how would you describe yourself?
Christina: Compassionate, Honest, Persevering.

Thank you, Christina, for paving the way for other women — especially those considering an engineering career — and for the outstanding, valuable work you do for our Company, customers and community. And thank you to all the other women who work at CPS Energy and help power Greater San Antonio!
Related story: Drawn to nature … and CPS Energy