Why did it fail? Because of high water table? In sandy soil, the water should have disappeared in a flash.
Another option, if the soil is indeed impervious, would be to excavate the drainage field area, and fill it with porous material. One item I located had this information: You may be in luck. I have installed a number of alternative system in Coastal NC and would recommend the pure flow system by Bord na mona. It is a above ground system with two tanks which pump the effluent into above ground pods filled with 7 layers of peat. The effluent leaving the bottom of the pods is very clean and this system may get you where you want to be. I would contact a soil scientist in you area and ask about designing a system for you lot.
Another option, if the soil is indeed impervious, would be to excavate the drainage field area, and fill it with porous material. One item I located had this information: You may be in luck. I have installed a number of alternative system in Coastal NC and would recommend the pure flow system by Bord na mona. It is a above ground system with two tanks which pump the effluent into above ground pods filled with 7 layers of peat. The effluent leaving the bottom of the pods is very clean and this system may get you where you want to be. I would contact a soil scientist in you area and ask about designing a system for you lot.