Related by context. Frequent words. (Click for all words.) 73 contaminate groundwater 62 contaminating groundwater 62 pollute groundwater 61 contaminate 55 gasoline additive MTBE 54 contaminated 53 suspected carcinogen 53 contaminating 52 polluted groundwater 51 fracking fluids 49 contaminates 49 additive MTBE 49 Toxic chemicals 48 contaminants 48 Hydrochloric acid 48 contaminant 48 MTBE 48 pollute 48 fracking fluid 47 harmful 47 Perchlorate 47 harmful toxins 47 contamination 47 harmful contaminants 47 odorless colorless gas 47 radioactive contamination 46 fracking 46 Radioactive material 46 deadly bacterium 46 carcinogenic chemicals 46 toxic algae blooms 46 polluted 46 Cap collects 46 toxic chemicals 46 radioactive contaminants 46 tetrachlorethylene 46 potentially carcinogenic 45 hydraulic fracturing 45 arsenic contamination 45 naturally occurring substance 45 harmful chemicals 45 Raw sewage 45 chlorinated solvents 45 groundwater contamination 45 chloramines 45 gasoline additive 45 chlordane 45 toxic byproducts 45 trace amounts 45 perchlorethylene 45 arsenic 45 aquatic organisms 45 toxic vapors 44 improperly disposed 44 furans 44 arsenic mercury 44 naturally occurring bacteria 44 perchlorate contamination 44 polychlorinated biphenyls PCBs 44 toxic substances 44 toxic stew 44 occurs naturally 44 polycyclic aromatic hydrocarbons PAHs 44 groundwater 44 saltwater intrusion 44 Hydraulic fracturing 44 Contaminants 44 methyl tertiary butyl ether 44 poisonous chemicals 44 chloramine 43 pollutes 43 Nitrates 43 lindane 43 gusher unclear 43 toxins 43 coal slurry 43 Contamination 43 red sludge 42 hydrofluoric acid 42 Anhydrous ammonia 42 carcinogen 42 contaminated groundwater 42 Fracking 42 mercury arsenic 42 toxic pollutants 42 methyl mercury 42 seep 42 perchlorate 42 trihalomethanes 42 oxygen depletion 42 Benzene 42 Dioxins 42 hexavalent chromium 42 Acrylamide 42 underground aquifer 42 tainted 42 cleaning solvents 42 colorless odorless 42 methylene chloride 42 polluted runoff 42 mercury contamination