Water quality

How many places I have fished without any real knowledge of water quality how many of you have a clue whats in the water we're you fish ?
Example comanche had or may still have an chemical additive plume MTBE
It was a mandated additive  for ca gasoline nasty stuff
Of course the delta has areas that are plain nasty at times

Example

agreed.  Was planning to fish the guadeloupe slough because it is close to my house and realized that is where the sunnyvale water treatment plant dumps its water.  I guess it will catch and release.  The water already looks pretty bad so don't need a report.  But for other spots around the bay, it would be good to know.