Just noticed an omission in my essay...

I wrote an essay about a research project I did for my common app. I noticed an environmental problem in my community, collected samples, and found a lab that let me come in and test them.

I just realized that my essay doesn’t include the fact that I used this research project to fulfill a school assignment. (We were supposed to do some sort of research in our community.) I was interested in the issue before, but the assignment definitely motivated me to get it done. It seems kind of dishonest to not include that it was a school assignment. Thoughts?