Article 15 4.

the construction or expansion of an urban wastewater treatment plant to treat increased loads or otherwise untreated loads of domestic wastewater is subject to prior authorisation in accordance with this Directive;

the benefits of the urban wastewater treatment plant in point (a) cannot for reasons of technical feasibility or disproportionate cost be achieved by other means, including the consideration of alternative points of discharge of urban wastewater plants, that would contribute to achieving the environmental objectives set out in Article 4 of Directive 2000/60/EC;

all technically feasible mitigating measures are taken to minimise the negative impacts of the urban wastewater treatment plant on the water bodies affected and are set out in the specific authorisations referred to in Article 14 of this Directive and this Article; those measures shall include, where required, treatment requirements more stringent than those applied prior to the increase in the domestic wastewater load, in order to meet the requirements of the Directives referred to in Part B, point 6, of Annex I to this Directive;

all technically feasible mitigating measures are implemented to minimise the negative impact of other activities causing similar pressures in the same water bodies.