I have several areas in my yard that are turning brown. After my irrigation system runs the appropriate time, I tried to stick a 6" screw driver into the ground. I had no issues around my lawn, besides these brown areas were I could only get the screwdriver in 2-4". I aerated in the fall and spring this year due to the lawn being so compact, but yet this is still happening. It seems like I can't get the soil to properly moisten 6" down without just letting the hose soak in those areas. My sprinklers seem to be providing proper coverage. That is why I am assuming it is the soil that isn't allowing the water to soak in. Does anyone have any solutions to this problem?
I'm with Giacomo on this - the likeliest explanation is detritus beneath the lawn causing these problems - it could be layers of aggregated stone clumped together in hard soil, or larger rubble like bricks or broken slabs. It could even be old large roots, though that's less likely, it's solid objects that usually cause this problem.
If you had a contractor lay the lawn fairly recently, then get them back to sort it out; otherwise, carefully cut out squares of turf and stack them to one side then dig around underneath to see what you can find/get out before replacing the turf you have removed. You may need to top up the soil prior to replacing turf to get it level with the rest of the lawn if you take out a fair bit of rubble...
I understand that the best way is to add compost over the entire area. Over some time, the soil gets healthier. Compaction means there is no air in it, so things like water cannot penetrate.