Related by context. Frequent words. (Click for all words.) 65 polychlorinated biphenyls PCBs 61 arsenic 61 chlorpyrifos 60 contaminants 59 trichlorethylene 58 fecal coliform bacteria 58 PCBs 57 fecal coliform 57 polychlorinated biphenyls 57 pesticides 57 #,# dioxane 56 Contaminants 56 contaminant 56 PFOS 56 PBDE 55 malathion 54 atrazine 54 organophosphates 54 nitrates 54 trace amounts 53 mg l 53 perchlorethylene 53 fecal bacteria 53 PBDEs 53 dioxins 53 methyl mercury 53 hexavalent chromium 52 PAHs 52 ppb 52 endocrine disruptors 52 toxic chemicals 52 chemicals 52 trihalomethanes 51 pesticide 51 vinyl chloride 51 coliform bacteria 51 PFCs 51 pollutants 51 radioactive cesium 51 toxicity 51 concentrations 51 triclosan 51 toxins 51 dioxin 51 Atrazine 51 Concentrations 50 coliform 50 contaminate groundwater 50 perchlorate 50 Nitrate 50 chromium 50 flame retardants 50 polycyclic aromatic hydrocarbons 50 mold spores 50 TCE 50 toxic pesticides 50 toxin 50 arsenic contamination 49 E. coli bacteria 49 DDT 49 turbidity 49 nitrate 49 Nitrates 49 mercury contamination 49 carcinogens 49 Arsenic 49 pesticides herbicides 49 phthalates 49 contamination 49 selenium 49 neurotoxins 49 Pollutants 49 PCB contamination 49 fire retardants 49 domoic acid 49 rotenone 49 pollutant 49 plasticizers 48 carcinogenic 48 VOCs 48 Cryptosporidium 48 Pesticides 48 solvents 48 Dioxins 48 pesticide residues 48 groundwater contamination 48 e coli 48 fecal contamination 48 Elevated levels 48 naphthalene 47 toxic pollutants 47 Perchlorate 47 brominated flame retardants 47 volatile organic compounds 47 pesticide DDT 47 nanograms per 47 air toxics 47 alkalinity 47 harmful chemicals 47 cesium 47 cyanuric acid