Retrieving the discrete concentration time series data to calculate the

value for the exceedance plot. Also did some rearranging of the code in
main.js so that code that can run before the siteInfo is done outside of
the promise resolution.
In my opinion we probably don't need templates for this but could be put directly in the DOM. However, this piece of code was already there so I didn't address this issue as it wasn't related to the ticket.