For every litre of washing powder you use, it takes 20,000 litres of water to treat it until it can re-enter our water system safely. It is water that cleans your clothes; the detergent (surfactant) just separates the water molecules to create a wetter water that can penetrate the fabric deeply. Surfactants are chemicals used to help remove dirt and grease from the substance being cleaned. Petroleum derivative based surfactants are derived from a non-renewable source, and biodegrade very slowly, forming even more dangerous chemicals as they do so. Look for natural surfactants based on vegetable products, which typically will not be found in “big name” cleaning products. See also detergents.