In most countries, the requirements for discharging to surface water are established in local legislation. 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.

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.