Related by context. Frequent words. (Click for all words.) 56 groundwater aquifers 55 treated effluent 55 recharge groundwater 54 shallow aquifer 54 wastewater effluent 54 salination 54 aquifers 54 sewage effluent 53 Aquifers 52 water 52 Effluent 51 desalinated 51 effluent 51 silts 51 mineral salts 51 brines 51 groundwater 51 Reverse osmosis 51 potable 51 Salinity 50 nitrate contamination 50 brackish 50 wastewaters 50 evaporation ponds 50 salinity 50 acidify 49 artesian wells 49 Turbidity 49 soil salinity 49 undrained 49 seawater intrusion 49 aquifer 49 naturally occurring arsenic 48 seepages 48 desalinate 48 reverse osmosis desalination 48 miscible 48 aquifer recharge 48 Coliform 48 Acidic 48 tailing ponds 48 wellfields 48 nitrification 48 desalting 48 biogenic 48 Ilmenite 48 DBPs 48 underground aquifer 47 de ionized 47 faecal contamination 47 reservoirs 47 basins 47 seawater 47 groundwater recharge 47 underground aquifers 47 oxygenating 47 embayment 47 Bentonite 47 groundwater depletion 47 basin 47 sludges 47 methane CH4 47 dissolved solids 47 effluence 47 deionized water 47 Ogallala aquifer 46 irrigated lands 46 subglacial 46 Kuan Yin Taiwan 46 groundwater basin 46 saponins 46 Potable water 46 tannic acid 46 fecal material 46 amphipods 46 alkaline soils 46 diatomite 46 faecal 46 Contaminated soil 46 industrial effluents 46 Slurry 46 subsurface 46 placer deposits 46 alluvial deposits 46 contaminate groundwater 46 irrigated crops 46 nanofiltration 46 sulfide minerals 46 marine sediments 46 uncontaminated 45 aquatic invertebrates 45 discharging wastewater 45 Soil erosion 45 headwater 45 Aquifer 45 Sediments 45 irrigated agriculture 45 Drip irrigation 45 Nitrates 45 brackish water 45 streambanks