Opal,
the pool you identified as the 'Arizona Pool' is correct and a photo of it is shown on the top of this page of the forum.
To the right of the pool, (the upstream side) is a thick grassy like area. It could be that various types of insects will make their habatit in that location over other areas because of the thicker vegetation and the warmer moisture coming from the pool and fissures nearby. Just my take on it.
I have never been bitten by any insects near that pool, but will make a point of checking it out the next time I am visiting the springs. You are the 2nd person I have heard, who has experienced being bitten there.