Related by context. Frequent words. (Click for all words.) 73 perchlorate 65 groundwater contamination 58 contamination 56 contaminated groundwater 56 contaminant 55 groundwater 52 Superfund site 52 contaminants 52 contaminated 51 arsenic 50 Superfund sites 49 hexavalent chromium 49 E. coli contamination 48 chromium 48 Toxic Substances Control 48 Contamination 47 mercury contamination 47 carcinogen 46 AQMD 46 coliform 46 bacterial contamination 45 tritium 45 MTBE 45 contaminated soil 45 toxic chemicals 45 polluted 45 EPA 45 TCE 45 nitrate 45 aquifer 44 coliform bacteria 44 nitrates 44 Safe Drinking Water 44 fecal coliform 44 Environmental Protection Agency 43 radium 43 E. coli 43 E. coli bacteria 43 pollutants 43 radioactive contamination 43 birth defects 43 hazardous waste 42 PBDEs 42 wastewater 42 methylmercury 42 fluoride 42 dioxin 42 pollutant 42 benzene 42 E. Coli 42 toxics 42 PCBs 42 ADEQ 42 ozone pollution 41 Environmental Quality 41 ppb 41 pollution 41 septic systems 41 PAHs 41 TCEQ 41 sediment 41 Disease Registry 40 aquifers 40 Clean Water Act 40 phthalates 40 PFCs 40 Groundwater 40 phthalate 40 Water Quality 40 pesticide residue 40 toxic algae 40 algae bloom 40 radioactive iodine 40 trace amounts 40 carcinogens 40 neurotoxin 40 toxins 40 dioxins 40 air pollution 39 biosolids 39 Diablo Canyon 39 borne illness 39 toxin 39 Aerojet 39 DEQ 39 polychlorinated biphenyls 39 Arsenic 39 ozone 39 effluent 39 Contaminated 39 pesticides 39 contaminating 39 gastrointestinal illness 38 hydrazine 38 chlorinated 38 hydrogen sulfide 38 Toxic Substances 38 radioactivity 38 pesticide 38 radioactive fallout 38 General Atomics