Walden is pleased to welcome our two newest employees to the team! Gabriella Castillo (pictured left) and Hayden McElduff (pictured right) both joined us in July as Project Engineers. Gaby is based in our headquarters in Oyster Bay, and Hayden works out of our Hudson Valley office. Both women are recent graduates of engineering programs. We are excited to see all that they contribute to our team and clients and to support their learning and growth as they begin their careers! Read on to learn a little bit more about each new hire.
Gaby Castillo
Gaby graduated from Hofstra University with a Bachelor of Science in Civil Engineering in May 2025. We actually first met Gaby at Hofstra’s Engineering and Computer Science Career and Internship Fair last fall!
Gaby brings with her an impressive background in the environmental field. This past spring, she worked as a Geology/Hydrogeology Intern for the New York State Department of Environmental Conservation (DEC), where she gained experience in environmental permitting and water supply systems. She also spent a couple of summers working as an Asbestos Project Monitor and Air Sampling Technician for another local environmental consulting firm. In this role, Gaby was responsible for activities such as reviewing technical documents, performing site visits, and compiling reports.
In her time at Walden so far, Gaby has been working on solid waste projects and chemical bulk storage permitting. She has also completed her OSHA 40-hour HAZWOPER training and NYSDEC Class A/B Operator certification, and is working toward her USEPA Method 9 Opacity/Visible Emission Evaluator certification.
Hayden McElduff, EIT
Hayden joins Walden after having completed her Master of Science in Environmental Engineering at Manhattan University in May 2025. She also earned a Bachelor of Science in Engineering in May 2024 from the same institution (when it was still Manhattan College). She has already attained her Engineer in Training (EIT) certification, which is the first major step in the journey to becoming a licensed Professional Engineer!
Hayden has already spent significant time developing her engineering skills through a number of notable positions. In the summers of 2023 and 2024, she worked as a Water Design Intern at a multinational engineering firm. In this role, she supervised hazardous material and pipe thickness testing at a water resource recovery facility and conducted inspections of stormwater and wastewater systems (including robotic sewer inspections in Flushing, Queens). Earlier in her academic career, Hayden also spent two years as a Civil Engineering Intern for another large engineering firm, where she worked on a major interstate improvement project and honed her technical and design skills.
In her first couple of months at Walden, Hayden has been working primarily on ambient air quality/sub-slab vapor testing and asset management projects. She has also attained her OSHA 40-hour HAZWOPER certification.
Work With Walden
Walden is currently looking to fill both entry-level and experienced engineering roles. Visit our careers page to learn more about the open positions available, as well as our benefits. If you are interested in discussing career opportunities further, contact us today at 516-559-6976.