Materials used for components in contact with water, e.g. O-rings, gland packings, gaskets, washers and lubricants should be compatible with each other and not foster microbial growth or react adversely with treatment chemicals.
The hot water tanks should have close fitting covers to prevent foreign matter entering into the water.
Hot water systems should be designed to heat the water to or above 60oC and calorifiers should be designed and installed so as to prevent stratification of temperature and collection of sludge.