Grit and other organic material interfere with the Coliform count. The organisms may remain viable but without division within the grit. The abrasive grit particles may cause damage to the cells and lead to less coliform count than the actual count. In general, grit is removed by placing grids that specifically remove grit. Or else, differential sedimentation is applied to remove grit. At the upstream source, generally the organisms enter the stream at a point source and hence are more concentrated. When they travel down, the cells gradually get dilution since the volume of water wherein the cells are spread increases with time and space. Hence, lesser density of coliforms is observed at a downstream site. Solution Grit and other organic material interfere with the Coliform count. The organisms may remain viable but without division within the grit. The abrasive grit particles may cause damage to the cells and lead to less coliform count than the actual count. In general, grit is removed by placing grids that specifically remove grit. Or else, differential sedimentation is applied to remove grit. At the upstream source, generally the organisms enter the stream at a point source and hence are more concentrated. When they travel down, the cells gradually get dilution since the volume of water wherein the cells are spread increases with time and space. Hence, lesser density of coliforms is observed at a downstream site..