2.—(1) The following parameters (“Group A parameters”) must be monitored at least at the minimum frequencies determined in accordance with the table in paragraph 3:—
(a)Escherichia coli, coliform bacteria, colony count 22 °C, colour, turbidity, taste, odour, hydrogen ion concentration (pH), and conductivity; and
(b)any other parameter, or other micro-organism, parasite or substance, (except radon, tritium and indicative dose) identified as relevant in the monitoring programme—
(i)by virtue of regulation 18(2) (as read with regulation 19(2)(a)); or
(ii)where relevant, through a risk assessment.
(2) Ammonium and nitrite must be included as Group A parameters, if chloramination is used.
(3) Aluminium and iron must be included as Group A parameters, if used as water treatment chemicals.