Related by context. Frequent words. (Click for all words.) 75 ppm 62 micrograms 60 picocuries per 59 ppb gold 59 arsenic 59 ppb Au 58 nanograms per 56 #ppm [001] 56 milligrams 55 microgram 54 perchlorate 54 nanograms 54 concentrations 54 chromium 53 ng mL 52 hexavalent chromium 52 contaminant 51 per milliliter 51 cesium 51 PM# [003] 51 becquerels 50 ozone 49 ng ml 49 radium 49 microgrammes 49 fecal coliform 49 Concentrations 48 Arsenic 48 μg 48 benzene 48 coliform 47 ppt 47 trace amounts 47 coliform bacteria 47 mmol L 47 pesticide residue 47 mg dl 47 anomalous gold 47 radioactive iodine 47 nitrogen dioxide 47 trichlorethylene 46 PCBs 46 PM#.# 46 mg dL 46 nitrate 46 dioxins 46 nitrates 46 g t silver 46 cadmium 46 antimony 46 dioxin 45 mercury 45 contaminants 45 mg kg 45 pollutant 45 grams 45 pH 45 g t Ag 45 milliliters 45 fine particulate matter 45 Elevated levels 45 grams tonne 45 Iodine 44 milligram 44 barium 44 detectable 44 g dL 44 sulfate 44 #ppm [003] 44 iodine 43 vinyl chloride 43 decibels 43 turbidity 43 mcg 43 pesticide residues 43 gpt Au 43 g Au 43 selenium 43 TCE 43 opt Au 43 per deciliter 43 toxicity 43 groundwater contamination 43 EPA 43 carcinogen 42 PAHs 42 g t 42 particulate pollution 42 g tonne 42 mercury contamination 42 fecal bacteria 42 degrees Fahrenheit 42 mL 42 ATSDR 42 hydrogen sulfide 42 alkalinity 42 #.#mg [004] 42 ° C 41 radioactivity 41 μm 41 microns