Stick to your job in NEA if you are interested in environmental work.

ECO is just a supervisor level job in charge of tying up loose ends at a construction site. Things like noise complaints, rubbish clearing, mosquito breeding, toilets, worker's hygiene. No career progression and your pay is subject to pressure from FTs who are ever willing to take lower pay than you. Your work also won't be appreciated and you are viewed as a cost liability to your company who would rather not have you around if not for HDB and LTA's requirements.

Fresh without exp. about 3k. Experienced at most 4.5k. 6 day work week.

I have never heard of local U engineering grad working as ECO. Is the economy that bad?