Chemicals giant Bayer has already invested 50 million euros in a carbon monoxide gas pipeline that will run from Dormagen to Uerdingen. But now a pensioner's protests are threatening to stall the project.Former safety engineer Erich Hennen has been blocking further development of the pipeline with one lawsuit after another - and he has no shortage of supporters. The pipeline opponents object first and foremost to the risks posed by the toxic and highly flammable gas. Unexploded bombs left over from the Second World War are another potential problem. But Bayer is keen to transport the carbon monoxide from one site to another as efficiently as possible, and argues that the project will also bring jobs to the region and generate tax revenue. Local politicians fear a mass protest might be brewing and are wondering how they can better involve citizens in the planning process at an earlier stage.