Related by context. Frequent words. (Click for all words.) 47 silt 45 sludge 44 algae 44 sand 43 silts 43 chippings 42 pollution 42 debris 42 red sludge 41 algal bloom 41 bleaching powder 41 water hyacinth 41 salvinia 41 Taihu Lake 41 heavily polluted 41 seaweed 41 sediment 41 mud 40 muck 40 dredged sand 40 toxic sludge 40 uncollected rubbish 40 pollutants 40 dioxin contaminated 40 topsoil 40 algae bloom 40 waterways 40 rotting vegetation 39 tailing ponds 39 soot 39 shorelines 39 unexploded munitions 39 polluted 39 bomb craters 39 debris littering 39 Toxic chemicals 38 uranium tailings 38 chimney stacks 38 seawaters 38 unexploded cluster bombs 38 pine logs 38 mine tailings 38 contaminated sediments 38 Soil erosion 38 PCBs polychlorinated biphenyls 38 garbage heaps 38 rubbish strewn 38 tar ponds 38 wheel barrows 37 rotting carcasses 37 toxic chemicals 37 rooster tail 37 deadfall 37 sooty 37 Eurasian milfoil 37 phosphorus 37 reed beds 37 gravel 37 toxic waste 37 seawater 37 groyne 37 absorbent booms 37 Dump trucks 37 noxious gases 37 grassy slopes 37 contaminated soils 37 gunk 36 dirt 36 roadbeds 36 weeds 36 phosphorous 36 Giant squid 36 oily residue 36 quicklime 36 uncollected garbage 36 toxins 36 mussel shells 36 dust 36 vegetative debris 36 goop 36 sulphate 36 duckweed 36 salination 36 cordgrass 36 sludges 36 polluted groundwater 36 dune grass 36 soil erosion 36 toxic algae blooms 36 Controlled burns 36 soot particles 36 pollutants emitted 36 tussock 35 baled hay 35 algal 35 toxic pollutants 35 exhaust fumes 35 toxic 35 granite boulders 35 absorbents 35 unbearable stench