(33)In order to ensure the protection of the environment, direct discharges of biodegradable non-domestic wastewater into the environment from certain industrial sectors should be subject to appropriate requirements. Those requirements should ensure that direct discharges from certain industrial sectors are subject to secondary, tertiary and quaternary treatment as necessary for the protection of the environment and human health, and that, upon final analysis, the parameters set for treated wastewater are respected or the same level of environmental protection is ensured.