Disposal of fly ash of Thermal Power Stations is to be done meticulously, Ash slurry from the plant is discharged into an ash pond. During the process ash gets settled down and standing water passes through decanting wells and filters of embankment. Water discharged through decanting wells does contain ash particles in excess of prescribed limit of 100 ppm. This results in pollution of natural water streams and ponds, making the surrounding fields infertile. Geotextile is expected to play a vital role in preventing the pollution due to effluent of ash ponds. Experiments are conducted in. the laboratory to find out the effectiveness of non-woven geotextiles in filtering the ash slurry. Various parameters that influence the filtration characters are discussed. The results help to conclude that geotextile can play a vital role in revitalising the functions of decanting wells and seeing that the ash concentration is within the allowable limits in the discharged effluent.