Related by context. Frequent words. (Click for all words.) 56 corroded pipes 55 pipeline rupture 55 pipelines 52 refineries 52 unplanned shutdowns 52 Train derailment 52 derailments 52 Ice jams 51 spills 51 train derailments 50 corroded pipe 50 Seepage 50 shutoff valves 50 ice jams 49 Tesoro refinery 49 Subsidence 49 natural gas 49 reservoirs 49 undersea pipelines 49 wellheads 48 storage tanks 48 Train derails 48 crude oil 48 Line 6A 48 oil 48 nitrate contamination 48 Line 6B 48 gas 48 contaminating groundwater 48 natgas 48 spillage 48 Derailment 48 tailing ponds 47 gasfields 47 Algae blooms 47 earth tremors 47 reservoir 47 sewage discharges 47 refinery 47 Aquifers 47 injection wells 47 Sayano Shushenskaya plant 47 floodings 47 Pipelines 47 spillages 47 Baiji refinery 47 pipeline 47 seepage 47 wells 47 Swollen rivers 46 Kirkuk Ceyhan pipeline 46 sanitary sewer overflows 46 spokesman Precious Okolobo 46 oil sheens 46 freight train derailment 46 Lisburne 46 Tar sands 46 Horizon oilsands 46 northern Alberta oilsands 46 basins 46 prompts evacuations 46 Quake jolts 46 Controlled burns 46 propane tanker 46 wellhead 46 Freight train derails 46 Boat sinks 45 Conemaugh River 45 THMs 45 Atchafalaya rivers 45 exceedances 45 oilfields 45 toxic dispersants 45 flowstation 45 sewage spills 45 reinjection 45 Muskeg River Mine 45 corrosion 45 flammable substances 45 Plains Midstream 45 Contaminated soil 45 Manhole covers 45 ruptures 45 tributary streams 45 Sulfur dioxide 45 salt domes 45 chlorine leak 45 Three Gorges reservoir 45 Soil erosion 45 unplanned shutdown 45 wastewater discharges 44 deplete oxygen 44 tectonic fault 44 groundwater aquifers 44 Kumkol 44 leakage 44 ruptured undersea 44 thawing permafrost 44 Heavy snows 44 Cheakamus River 44 Anacortes refinery