Hey guys, got the result and PASSED
Thank you to everyone who provided advice along the way. It was a tough journey but it is definitely doable!
Also I will provide a write-up shortly of what materials I used to study.
Update: Here's how I prepared.
I studied for about 6.5 months (almost every day after work and on the weekend). I studied both calculations and reading as well. The prep material and references I used were:
Intro to Environmental Engineering textbook
Air Pollution Control by Cooper & Alley
Other materials used for reading were Environmental Law Handbook, RCRA Orientation Manual, EPA Fact Sheets, etc.
PPI PE Environmental Practice by Wane Schneiter
PPI PE Environmental Practice Exam by Wane Schneiter (two sample practice exams)
PPI2PASS On-demand Course (sample quizzes and exams were useful. You can also watch the lectures if you need to)
NCEES PE Practice Exam
So overall, I think the PPI material helped me the most with my preparation. I can agree with everyone else that the exam had a lot of qualitative questions. For these types of problems, I spent a good amount of time reading and memorizing facts (which I'm glad I did lol) from my textbook, codes & regulations, printed handouts, etc. I also wrote A LOT of flashcards because that helps me to remember. Good luck to all