Groundwater contamination resulting from waste disposal was studied in the vicinity of a solid waste disposal site and at five wastewater stabilization ponds. Results indicated that during periods of high groundwater table elevation, groundwater in the immediate vicinity of a refuse area mya not meet criteria for human consumption. A trench constructed to intercept degraded groundwater flowing from the active disposal site beneficially affected the quality of the groundwater. Studies of five sewage stabilization pond sites found that soil is effective in removing large percentages of phosphate, nitrogen, chemical oxygen demand, and bacteria from wastewater passing through it. Pollution of a shallow groundwater table can be controlled to some degree by interception trenches or tiles.