Originally Posted by stdreb27
Not really. The soaps and things that we throw down there don't stay in solution. They eventually separate out and float to the top of the water, forming a scum layer. Solids (read: poo) settles to the bottom and forms a sludge layer.
The septic tank has baffles to allow only the middle layer (gray water) to exit onto the drain field.
The problem renogaw describes is due to the fact that salt doesn't separate out. Salt dissolved in water will stay dissolved, so it won't separate into scum or slude so it'll end up out in the drain field. Since the drain field depends on vegetation growing above it, and since salt kills vegetation, it will start to degrade the operation of your septic system, not to mention the corrosive effect that salt has on the concrete tank, and all the other stuff he mentioned.
Of course, you could cover your yard in chaeto, that way the saltwater will actually help... rotfl