5.—(1) Where disinfection forms part of the preparation or distribution of water; the relevant person (as defined in section 80 of the Water Industry Act 1991(1)) must—
(a)design, operate and maintain the disinfection process so as to keep any contamination from disinfection by-products as low as possible,
(b)carry out this process without compromising the performance of the disinfection process,
(c)ensure that the performance of the disinfection process is maintained,
(d)in order to verify the performance of the disinfection process, keep records of the maintenance undertaken to comply with the requirements of the disinfection process, and
(e)keep copies of those records available for inspection by the local authority, for a period of up to five years.
(2) In this regulation “disinfection” means a process of water treatment to—
(a)remove; or
(b)render harmless to human health,
every pathogenic micro-organism and pathogenic parasite that would otherwise be present in the water.