The Court held today in C-60/18 AS Tallinna Vesi and agrees with its AG re the possibility of national criteria, yet unlike Ms Kokott does not see an obligation in the WFD for the Member States to have a proactive vetting and decision procedure. It does not give much specification to its reasoning, other than a reference to the ‘circumstances of the case’. This may refer, but I am speculating, to applicant wanting the authorities generally to sign off on its production method, rather than requesting an opinion on an individual stream. In other words: fishing expeditions must not be entertained.
If my interpretation is right it underscores what I have remarked elsewhere on the regulatory process, for instance in the case of circular economy: in a grey regulatory zone, we need to think of mechanisms to assist industry in embracing environmentally proactive solutions, rather than driving them into incumbent technologies or worse, illegality.
Handbook of EU Waste law, 2nd ed. 2015, OUP, 1.166 ff and 1.189 ff.