Regulation 4 Sampling and analysis

The provisions of this regulation apply as respects the taking of samples of inland freshwaters, coastal waters and relevant territorial waters in relation to their classification in accordance with regulation 3.

Samples shall be taken under this regulation at a frequency sufficient to show any changes in the aquatic environment, having regard in particular to natural variations in hydrological conditions.

Where a discharge containing any substance listed in column (1) of any of the Schedules is made to waters mentioned in paragraph (1), samples shall be taken at a point sufficiently close to the discharge point to be representative of the quality of the aquatic environment in the area affected by the discharge,

Samples taken under this regulation in relation to relevant territorial waters, coastal waters or inland freshwaters to which the classification DS1, DS2 or DS3 is for the time being applied shall be analysed using the relevant reference method of measurement respectively specified in column (3) of Schedule 1, 2 or 3 or other methods which have limits of detection, precision and accuracy at least as good.