Related by context. Frequent words. (Click for all words.) 78 aquifer 74 groundwater 73 aquifers 69 underground aquifers 65 Aquifer 62 Groundwater 62 reservoir 61 water 61 treated effluent 59 contaminated groundwater 59 Edwards Aquifer 59 reservoirs 58 Ogallala Aquifer 57 sediment 56 outfall 56 leachate 56 septic tanks 56 groundwater contamination 56 drainage basin 55 headwaters 55 wastewater 54 watercourse 54 septic systems 54 creek 54 contaminants 54 effluent 53 brackish water 53 sewage 53 basin 53 brackish 53 floodplain 53 watersheds 53 artesian 52 seepage 52 turbidity 52 mgd 52 arsenic 52 soils 52 nitrates 52 septic 52 freshwater 51 sandy soils 51 wetlands 51 basins 51 wells 51 hydrogeologist 51 Reservoir 51 flood plain 51 dissolved oxygen 51 stormwater 51 silt 51 hydrologic 51 waterlines 51 Sediment 50 drainage 50 streambed 50 ponds 50 river basin 50 cistern 50 fecal coliform 50 nitrate 50 potable 50 septic tank 49 sedimentation 49 fecal coliform bacteria 49 wetland 49 sewer 49 sewer pipes 49 stormwater runoff 49 lake 49 contaminated soil 49 chlorination 49 catchment 49 tributary 49 creeks 49 lagoons 49 sanitary sewers 49 storm drains 49 sediments 48 rainwater 48 wastewater treatment 48 lakes 48 stormwater drainage 48 brine 48 contaminant 48 Treatment Plant 48 sinkholes 48 raw sewage 48 salinity 48 perchlorate 48 riverbed 48 storm sewers 48 sanitary sewer 48 seawater 48 fecal bacteria 47 tributaries 47 reverse osmosis 47 backflow 47 retention ponds 47 subsurface 47 Water Treatment Plant