>"I wouldn't want to do a MS in engineering only to find out that a company wouldn't consider me in the first place on basis of age (and making a career change so late in life). Could you provide any advice/insight? Thanks..."
Chris: I have a co-worker and friend doing environmental engineering and he got his BS (Ag Eng) in his early 30s when he decided he didn't want to be an old guy swinging a hammer. And his MS (Env Eng) at Berkeley at age 42. And he's found a number of jobs in the 15 years since then.
But, I'd have to caution you that a lot of us got into Environmental Eng (in California at least) 15-20-25 years ago. And it's a more mature market now than then. There's more competition for the jobs, the margins are tighter and your best chance to get promoted is to poison your boss (ah, but we know how to do that!).
People do this work from a variety of backgrounds. I've worked with, of course, lots of Civils and Geologists. But also geographers, biologists, chemists, and even a few liberal arts types. The geographers usually come up through GIS systems, the bios in EISs and bio surveys, the chemists in the lab or in toxicology. The trick, in my mind would be to be in office that valued cross-training and didn't pigeonhole you into whatever your starting position was. I started as a tech before I had my BS, was bright-eyed and bushy-tailed, worked as a system designer, got my Engineeer-in-Training and later my PE (there are paths to do so without a degree) and went Staff Eng, Project Eng, Senior Eng. Then I thought I should graduate before my children do and finally finished my degree.
I too, like the "make the world better place" aspect of it. I learned long ago that writing a better computer game, sending out 700,000 pieces of junk mail or making "products for a better tomorrow" like Cheetios or Naplam didn't excite me. Nor did working for some huge, Dilbert-like corporation. The other continuing draw to Env Eng is all the head scratching work. There's a ton of stuff we DON'T know how to do still, and while cleaning up a corner gas station - impossible 20 years ago - is now easy, heavy metals, chlorinated solvents, and pesticides are tougher. We keep getting better at it, and it's kind of cool to spend some toxic polluter's money to learn how to do your job better. That's UNLIKE a lot of engineering work. At a utility or DOT, it's pretty cookie-cutter. Important stuff and important to do right, but not a lot of creativity involved. Whereas it's an odd month that I don't come up with a patentable idea.
One approach would be, if it works financially, to apply for technican positions and sell yourself like this: "I want to be the quickest-learning, most talented tech you've ever had." (all PMs fight to have that guy on their jobs, it adds huge value, avoids many problems, etc). "And, I want a path for advancement. Where can that tech position lead me?" Professionals who have come up the ladder that way are, IMNSHO, much more capable of teaching others, budgeting their projects and designing equipment when they've been in trenchs. Also, the hands-on professional can always pitch-hit doing field work when the projects or budgets demand it. Whereas other professionals, tasked to write the reports, would have no idea how to operate the pump to get the water samples that generated the data that went into the report.
This work is 10% stuff you learned in school and 90% stuff you learn on the job. As are most tech jobs. Coming into it with a different academic background, IME, adds to the team because there are already plenty of civils and geos at the table.
Hope that helps, David