The data on here does come from a number of places. One of which may be county tax records.
Here is something to think about.....if it was fed from Washington County tax records and they have it at 2200 sq. ft. and you chase it and have them correct it at the county level, your property taxes will likely almost double.
I know what I do if I were you, but it's up to you. I might just not worry about this being incorrect on here, but make sure through your agent that it is correct on MLS. I trust you are working with a full service brokerage. My website has MLS info on it along with my contact info and the address is www.asktoddheknows.com I'd be happy to help if you don't have an agent helping you.