In most countries, the requirements for discharging to surface water are established in local legislation. Many countries apply fixed values. However, there are also countries that link the discharge requirements to the volume and flow rate of the water receiving the discharge. In almost all cases, a biological (anaerobic and/or aerobic) treatment step is required. Marel Water Treatment provides various systems: BioFlot®, BioArt®, BioBrane®, BioClar®,Voltaflow®, Voltaflot® and Voltamix®,” each with their own characteristics. Under critical conditions, additional measures may be necessary to be able to handle emergencies. Marel Water Treatment is able to purify the water to any desired degree of purification.