Related by context. Frequent words. (Click for all words.) 58 shallow aquifer 58 nitrate contamination 58 polluting groundwater 57 perchlorate contamination 57 haloacetic acids 57 naturally occurring arsenic 56 contaminating groundwater 56 contaminate groundwater 55 trichlorethylene TCE 55 groundwater 54 Septic tanks 54 Perchlorate 54 groundwater aquifers 54 groundwater plume 54 wastewater effluent 54 Coliform 54 contaminated 53 organochlorines 53 sewage effluent 53 THMs 53 contaminate drinking 53 polluted groundwater 53 residual chlorine 53 Methylmercury 53 triclocarban 53 Coliform bacteria 53 E coli bacteria 52 Hexavalent chromium 52 faecal contamination 52 contamination 52 TCE contamination 52 Kuan Yin Taiwan 52 groundwater contamination 52 Chlorination 51 Stormwater runoff 51 Chlorinated 51 Hadnot Point 51 polluted 51 perchlorate 51 perfluorochemicals 51 chlorinated solvents 51 irrigating crops 51 Nitrates 51 seepages 51 salinization 51 DBPs 51 MTBE contamination 51 coliforms 51 Thoroughly cooking 50 contaminants 50 total coliform 50 Toxic chemicals 50 Potable water 50 Odd numbered addresses 50 Diesel exhaust 50 Sedimentation 50 arsenic mercury 50 PFBA 50 pollute groundwater 50 contaminant 50 organochlorine pesticides 50 aquifers 50 nitrate concentrations 50 bioaccumulation 50 bd.className + = 49 Pitzarella 49 Contaminants 49 dieldrin 49 arsenic concentrations 49 groundwater depletion 49 iron manganese 49 e coli bacteria 49 Soil erosion 49 carbon tetrachloride 49 total dissolved solids 49 Raw sewage 49 arsenic contamination 49 Enterococcus 49 harmful contaminants 49 Hydrogen sulfide 49 Trichloroethylene 49 Contaminated soil 49 salination 49 trihalomethanes 49 tetrachlorethylene 49 suspected carcinogen 49 Algae blooms 49 deplete oxygen 49 maximum contaminant 49 stormwater discharges 49 water 48 gully erosion 48 Domoic acid 48 flouride 48 microbial contaminants 48 arsenic cadmium 48 naturally occurring radioactive 48 nonpoint sources 48 chemically contaminated 48 fecal contamination 48 phosphorus runoff