Question
We live in NJ near the shore.  We have kentucky blue grass sod on sand.  In our community, the grass at the rain downspouts turns yellow and dies. The die off continues like a cancer as the water travels.  Our association has tried to identify the cause to no avail.  I have had several homes and never had this problem.  Any suggestions?

Answer
The runoff appears to be directly associated with the problem in more than one residences. That would suggest that something in the water is toxic to the grass. The rainwater flows off the roof (material) and down the spouts. I would look to those two as a possible source of contamination.