SciFantasy - Breath of Dragons and The Dry Library

Greetings! This is stuck in my head today and I cannot remember the book.

I probably read it in the late 90's but don't remember how old it would have been. I remember 3 distinct facts about it (it wasn't good, but it was memorable!)

1. I think the main 'bad guy' everyone was afraid of was a dragon. It turned out to be gay.

2. There was a library filled with the most boring books in the world. The topics were SO dry they turned the surrounding landscape into a desert. (LOL)

3. There was something in the water killing animals. A character called it the "Breath of Dragons" (BOD). I think that was the main quest.

The author was either an engineer or chemist, as BOD is Biochemical Oxygen Demand, and I recall at the end of the book an author's explanation on how he came up with the ideas for the novel.

It's been decades, and for some reason this morning I thought of this. And now it's stuck in my head.

TYIA!