Water quality standards

14.—(1) At each point of compliance, water must not contain—

(a)a micro-organism, parasite or substance which (in number or concentration) poses a potential danger to human health; or

(b)a parameter which exceeds its parametric value in Table A or Table B.

(2) At the point of compliance, the sum of the following must not exceed 1 mg/l:—

(a)nitrate (in mg/l) in the water, divided by 50; plus

(b)nitrite (in mg/l) in the water, divided by 3.

Derogations from the water quality standards

15.  Schedule 5 makes provision for derogations.

Duty of care: supplies of water

16.  A person, in relation to a supply of water, must not take any action which has the effect of allowing any deterioration of the quality of the water (in so far as that is relevant for the protection of human health).

Duty of care: substances and materials

17.  A person who, in relation to a supply of water, modifies any part of a private water supply system or introduces any substance to the water supplied (for purposes in connection with the distribution or preparation of the water) must ensure that no substance or material used or introduced for those purposes (or any impurity associated with any such substance or material)—

(a)remains in the water (including, in particular, at the point of compliance) in concentrations higher than is necessary for the purpose of their use; or

(b)reduces the protection of human health otherwise provided for by these Regulations.