hello aspirant ,

here are some links where you can get previous years enviromental engineering question papers:

https://www.manaresults.co.in/download.php?subcode=RT32011

https://www.indianuniversityquestionpapers.com/2016/11/ce6503-environmental-engineering-i-all-previous-years-question-papers.html

https://auhippo.com/2018/02/22/ce6503-environmental-engineering-1-previous-year-question-papers/

https://brpaper.com/ptu/b-tech/civil/5/ee-1

https://www.vidyarthiplus.com/vp/Thread-CE2304-Environmental-Engineering-I-Question-Paper-Collection

Hope this will help you!