“84 In that connection, it must be observed that the Court has already held that it would be incompatible with the Directive to restrict the identification of waters affected by pollution to cases where agricultural sources alone give rise to a concentration of nitrates in excess of 50 mg/1 when the Directive expressly provides that, in establishing the action programmes under Article 5, the respective nitrogen contributions originating from agricultural and other sources are to be taken into account (Case C-293/97 Standley and Others [1999] ECR I‑2603, paragraph 31). Consequently, the mere fact that domestic or industrial waste also contributes to the nitrates levels in Walloon waters is not in itself sufficient to exclude application of the Directive.”
“86 In that connection, it must be observed that, according to a document supplied by the Belgian Government, Walloon agriculture contributes 19% of the total nitrogen in the Meuse basin and 17% of the total nitrogen in the Escaut basin. Those two rivers cross the Walloon Region and drain into the North Sea. It must be pointed out that, although minor, those contributions are by no means insignificant. 87 It is clear from paragraph 35 of the judgment in Standley and Others that the Directive applies to cases in which the discharge of nitrogen compounds of agricultural origin makes a significant contribution to pollution. 88 Moreover, the eutrophication of the North Sea is caused by numerous actors who, considered individually, indeed make a minor contribution. To follow the reasoning of the Belgian Government would accordingly run counter to one of the express purposes of the Directive, namely protection of the North Sea. 89 Consequently, that argument cannot be upheld.”
“The Nitrates Directive refers to both ‘nitrates’ and ‘compounds of nitrogen’. The DEFRA Method Review Group, having reviewed the Directive and the current scientific understanding of the behaviour of nitrogen compounds in the environment (Nitrates Directive Annex I.B) agreed that the assessment of pollution should properly be based on all measured forms of inorganic nitrogen.”
“The inclusion of ammonium in the estimate (TIN) of total potential nitrate pollution is precautionary, based on the rapid oxidisation of ammonium to nitrate in river waters.”
“36. The reasons for a decision must be intelligible and they must be adequate. They must enable the reader to understand why the matter was decided as it was and what conclusions were reached on the "principal important controversial issues", disclosing how any issue of law or fact was resolved. Reasons can be briefly stated, the degree of particularity required depending entirely on the nature of the issues falling for decision. The reasoning must not give rise to a substantial doubt as to whether the decision-maker erred in law, for example by misunderstanding some relevant policy or some other important matter or by failing to reach a rational decision on relevant grounds. But such adverse inference will not readily be drawn. The reasons need refer only to the main issues in the dispute, not to every material consideration. They should enable disappointed developers to assess their prospects of obtaining some alternative development permission, or, as the case may be, their unsuccessful opponents to understand how the policy or approach underlying the grant of permission may impact upon future such applications. Decision letters must be read in a straightforward manner, recognising that they are addressed to parties well aware of the issues involved and the arguments advanced. A reasons challenge will only succeed if the party aggrieved can satisfy the court that he has genuinely been substantially prejudiced by the failure to provide an adequately reasoned decision.”