Can a sticky element stop at a particular place

Below the header, H1 and opening paragraph, I’ve created an H2 that says “Treatment Processes” and sub-copy block that is sticky. The goal is to get it to float to the left of the treatment process content and once that section ends, it would remain at the bottom of that light gray section. Right now it continues to scroll with the user down the page. Is it possible to set a final scroll destination with your plugin? Thanks!

The page I need help with: [log in to see the link]