Related by context. Frequent words. (Click for all words.) 73 contaminate drinking 65 contaminate 57 groundwater 54 groundwater contamination 54 contaminants 54 contaminated 53 contaminating 53 Perchlorate 52 contaminates 52 aquifers 52 pollute 52 fracking 51 underground aquifers 51 contamination 51 underground aquifer 51 contaminant 51 contaminated groundwater 51 perchlorate 50 Nitrates 50 methane 50 sewage sludge 49 Raw sewage 49 aquifer 49 toxic chemicals 49 arsenic 49 Contaminants 49 gasoline additive MTBE 49 coal slurry 49 contaminated soil 49 biosolids 49 leachate 49 polluted 48 treated effluent 48 arsenic contamination 48 radioactive contaminants 48 hydraulic fracturing 47 methane gas 47 perchlorethylene 47 leach 47 effluent 47 fumigant 46 pesticides 46 harmful chemicals 46 Contamination 46 carcinogen 46 toxic substances 46 poisonous chemicals 46 irrigate crops 46 septic systems 46 environmentally harmful 46 trace amounts 46 hydrofluoric acid 46 methyl tertiary butyl ether 46 septic tanks 46 radioactive tritium 46 chlorinated 46 groundwater pumping 46 Groundwater 46 carcinogenic 46 contaminated soils 45 polluted runoff 45 gasoline additive 45 chlorides 45 nitrates 45 polychlorinated biphenyls PCBs 45 deadly bacterium 45 MTBE 45 trihalomethanes 45 sludge 45 byproducts 45 pollutes 45 wastewater 45 hydrofracking 45 occurs naturally 45 leaching 45 Atrazine 45 carcinogens 45 harmful 45 harmful toxins 45 saltwater intrusion 45 improperly disposed 45 toxic pesticides 45 leached 44 Dioxins 44 toxins 44 Pollutants 44 pollutant 44 toxic pollutants 44 hazardous chemicals 44 trichlorethylene 44 pesticides herbicides 44 #,# dioxane 44 Fluoridation 44 frack 44 chicken manure 44 Fracking 44 fecal contamination 44 selenium 44 chlorine 44 Hydraulic fracturing 44 sediment