My questions are:
1-When microbial testing is required in purified water system?
2- What are the cases that require microbial testing for all sample and use points in either purified water loop or water treatment unit? and what are the cases that require microbial testing only in a specific location in the purified water loop or water treatment unit?
to be more clear, some times and after maintenance we do microbial testing for all use points and sample points but in some maintenance events we do that only in a specific location where the maintenance occur, so how to know whether we need microbial testing for all points or only for specific points?
thanks in advance