Question

Pic of sod   I had a contractor put in st augustine sod about a week ago.  He spread dirt over my already existing yard and placed the sod on top of it.  I've been watering it twice a day, at 10am and 10pm for the last week, giving it about an 1/2 inch of water a day.  But the grass is turning brown.  A lot of the sod has turned brown and is growing by the day.  When I walk on the sod it was extremely wet and making squishing noises, so i cut back on the watering to once a day.  What can I do to get the sod to green back up and save my investment?  I have attached pictures.

Answer
 I think that we can safely rule out shortage of water as the problem here. Over-watering can cause fungus diseases and you have got to confirm this before you can attempt to treat.
I suggest that you take a piece of the sod that shows good and bad patches, to your County Extension Office and let them help you identify the problem.
They will have suggestions for a remedy.