A - Urban wastewater treatment and nitrates from agricultural source
1 - Directive 91/271/EEC concerning urban wastewater treatment: Monitoring
Monitoring
Monitoring must be implemented, and Member States must provide the Commission with all relevant information concerning the monitoring method used. Flow-proportional or time-based 24-hour samples shall be collected “at the same well-defined point in the outlet and if necessary in the inlet of the treatment plant in order to monitor compliance with the requirements for discharged waste water laid down in this directive.” The minimum annual number of samples shall be determined according to the size of the treatment plant and be collected at regular intervals during the year in compliance with a table, and depending on the level of p.e. (Annex I-D). According to the Court of Justice, while these provisions refer to “a continuing obligation aimed at ensuring that discharges satisfy ‘over time’ the quality requirements which they must have satisfied since the entry into operation of the treatment plant”, they do not require that samples be collected over a full year, and “where a Member State is able to submit a sample meeting the requirements set out in Annex I.B to Directive 91/271, the obligations arising under Article 4 of that directive must be deemed to be satisfied.” 