I live in London too. The water is perfectly drinkable straight out of the tap. Your comment about needing to boil the water to make it drinkable is truly biza

I live in London too. The water is perfectly drinkable straight out of the tap. Your comment about needing to boil the water to make it drinkable is truly bizarre. I know of precisely zero people here who boil tap water before drinking it. UK tap water is safer that bottled water because it is monitored much more closely. The responsible government body is the UK Drinking Water Inspectorate. You can read the reports on their website (a good overview is the annual summary letter to the government at [1]). In 2016, 99.96% of samples met the quality requirements of the EU Drinking Water Directive. If you are particularly sensitive to residual chlorine, the DWI advises letting the water stand for a couple of hours [2]. No need to boil or filter. Of course, if you search online, you are more likely to see advice from makers of water filters saying you need to filter the water... [1] http://www.dwi.gov.uk/about/annual-report/2016/letter-eng.pdf http://www.dwi.gov.uk/about/annual-report/2016/letter-eng.pd... [2] http://dwi.defra.gov.uk/consumers/advice-leaflets/chlorine.pdf http://dwi.defra.gov.uk/consumers/advice-leaflets/chlorine.p...