Abstract: A landfill for the permanent disposal of wastewater sludge. The landfill includes an impoundment having a base that is substantially liquid impervious. Dikes supported by the base surround the perimeter of the base where needed. A liquid collection and conveying system is embedded in a liquid pervious layer which overlies the base; this system operates to dewater wastewater sludge deposited within the impoundment. The impoundment is adapted to be closed after the sludge is dewatered by spreading a liquid impervious layer over the dewatered sludge.