These Regulations prescribe a system of classifying the quality of inland freshwaters, coastal waters and relevant territorial waters (as defined in reg. 2). Regulation 3 and Schedules 1 to 7 create a system for classifying waters according to the presence in them of concentrations of the dangerous substances listed in the Schedules. Sampling requirements are prescribed in regulation 4. Regulation 5, by modifying section 4C of the Water Act (Northern Ireland) 1972, requires (and enables) the Dep