If you want to swim in the lake, I would suggest you do your own research - as the facts do not support that work has been done or is being done to consider the lake safe for recreational swimming based on Mexico's standards. Testing for bacteria is one small piece of what qualifies as safe for swimming. I know articles have been published - and I just finished fact checking one - and it failed.
Only a few days ago, 3 people drowned in the lake - waves sunk the boat - they were 10 meters from shore. This is a shallow lake and can be treacherous.
What about the snakes in the water? No one has said anything about them.