Related by context. Frequent words. (Click for all words.) 61 discharges 56 contaminants 56 pollutants 56 wastewater 55 untreated sewage 55 effluent 54 pollution 54 turbidity 54 stormwater runoff 54 groundwater 53 effluents 53 sediment 52 raw sewage 50 groundwater contamination 50 Clean Water Act 50 sewage 50 sedimentation 50 leachate 50 contamination 49 contaminated groundwater 49 stormwater 49 hazardous waste 49 hazardous wastes 49 wastewater treatment 48 pollutant 48 tributaries 48 contaminant 47 environmental impacts 47 DEQ 47 air pollution 47 polluted 46 algae blooms 46 mercury emissions 46 mercury pollution 46 waterways 46 Environmental Quality 45 bacterial contamination 45 septic systems 45 coliform bacteria 45 PCBs 45 discharge 45 sediments 45 DEP 45 Water Quality 45 phosphorus 45 dissolved oxygen 44 watersheds 44 MPCA 44 nitrates 44 sludge 44 biosolids 44 phosphorous 44 mercury contamination 44 toxic chemicals 43 algae bloom 43 waste disposal 43 polychlorinated biphenyls 43 impoundments 43 sewage treatment 43 tributary 43 salinity 43 sewage sludge 43 Environmental Protection Agency 43 Minnesota Pollution Control 43 Environmental Protection 43 EPA 42 hydrogen sulfide 42 sulfur dioxide emissions 42 aquifer 42 toxic substances 42 IDEM 42 landfills 42 contaminated soil 42 aquifers 42 sulfate 42 dewatering 42 silt 42 methane 42 headwaters 42 storm drains 42 rivers 42 hazardous chemicals 42 River basin 42 retention ponds 42 waste 42 hazardous substances 41 chromium 41 seepage 41 overflows 41 toxics 41 nitrate 41 E. coli bacteria 41 Groundwater 41 ADEQ 41 lagoons 41 environmental 41 Environmental Protection DEP 41 CAFOs 41 storm sewers 41 tailings 41 toxic waste