Should I be concerned that my sump pail is regularly half full?
My last home a daylight basement had a similar issue when we purchased it. A deep French drain in front of the house with drain legs going down the side of the home completely solved our problem along with epoxy coating the entire floor of the lower level. The drain legs down the side of the house were dug 2 ‘ below the foundation level at the bottom and extended a few feet until the slope left the drain open. Perf pipe in a sock and back filled with rock the lower area was always green even in late summer +jhw20.  so I think we had a small spring  or the drain was just very efficient at collecting the rain water as that home is on a very steep hill. 
I have had good luck epoxy sealing slabs but not cinder block walls.  Creating a French drain that ties in with the rock under the slab and or foundation and extends below the dump level below the house may eliminate your standing water issue. In my last place I was not sure if we had a spring but the runoff from up the hill was washing out a paved lower driveway and I was adding a new circular one so I added the drain to divert any water around the home and then continued down the hill several feet away from the house but at the bottom corners worked back until hitting the rock. Make sure if you rent a ditch witch on a steep hill to get insurance when you rent , let’s say they will roll down a hill if the bar is not in the trench Oops.