Think Green Classroom is a science site focused on environmental issues that has a lot of good resources, including online interactive exercises accessible to Intermediate English Language Learners.
It’s “powered by Discovery Education” (whatever that means) and is part of a larger site for Waste Management, a huge company. As long as you, and your students, stay on the “Classroom” section, I think you’ll be pleased with what you find. The rest of the site is an infomercial for the company, including how wonderful their landfills are.
I’ll be adding direct links to their interactives to the Science page on my website.