Sampling is not the same as risk assessment
A sample shows what was detected at a particular location and point in time. A risk assessment considers the whole system and how it is designed, operated and managed.
Domestic rental properties
HSE guidance explains that the risks in many normal residential hot and cold water systems are low, and routine sampling is not generally required simply because the property is let.
When can sampling be useful?
Sampling may be appropriate where the risk assessment, system history, occupancy, control failures or other circumstances justify it. The number and location of samples should be chosen to answer a clear question about the system.
What happens if results indicate a problem?
The response depends on the result, the system and the people at risk. Investigation may include checking control measures, temperatures, stagnation, system condition and whether cleaning or disinfection is required.
