Due to the levee breach of the tailings pond (sludge reservoir) of the Hungarian Aluminium Ltd. (MAL Ltd.) located in Hungary around 100 km south-west of Budapest in the surrounding area of Ajka town on 4 October 2010 a large amount of industrial red sludge spill occurred and caused significant environmental damage. The highly alkaline sludge from the reservoir entered into the Torna creek through which the pollution reached the Marcal River.
The pollution plume reached the Marcal River at 18:00 pm on 4th October where the recent flood wave was already decreasing therefore the transport of the pollution fortunately slowed down. The head of the plume passed the village of Mersevár at 15:00 pm 5th October. In the morning of the 5th October a warning message was sent out to the Danube basin countries by Hungary through the AEWS/PIAC alert system of the Duanube Protection Convention.
At the Governmental Coordination Committee meeting held at 16:00 on 5th October 2010, decisions have been made about immediate reconstruction of the levee of the tailings pond and about the further treatment of the residues of red sludge in the area.
For the mitigation of the environmental damage the Environmental and Water Directorates involved (Székesfehérvár, Szombathely, Győr) ordered emergency preparedness status on the same day. From 16:00 pm on 4th October the highest alert level III. has been in force along the Torna creek and Marcal River on a total length of 92.3 km. In the morning of the 5th October warning message was sent out to the Danube basin countries by Hungary through the AEWS/PIAC alert system of the Danube Protection Convention.
In the framework of the mitigation activity in order to reduce the alkaline effect gypsum has been spread since the morning of the 5 October in the village Kolontar, later in Devecser and Somlóvásárhely as well as into the Marcal River at the bridge between Szergény and Vinár. The pouring of the material is continued from aeroplane. At the downstream section of the Marcal River (at 22 river km) gypsum–depot has been created at Mórichida. To increase efficiency of the mixing of the gypsum and the pollutant water jets are used. As result of the measures the pH value already dropped to pH 10.5 in the Marcal River according to the latest analytical measurements.
Hungary has already been taken intensive measures on the whole length of the Marcal River before the arrival of the pollution plume to settle down the suspended solids possibly contaminated by heavy metals. For this reason decision was made to construct 7 underwater weirs, from which 4 are already ready.
Hungary is ready if necessary to localise the pollution by releasing it to the agricultural or other lands along the Marcal River. In case of such an inundation the given lands will be expropriated and remadiated.
In order to reach a tolerable level of pH an intensive neutralisation process is going on at the end-section of Marcal River (upper of its confluence) which has already resulted in a near to 9 pH value of the water discharging into the Raba River. It was achieved by neutrilaziation effect of bio-acetic-acid. The water reaches the Danube after further dillution process in the Raba and the Mosoni-Danube Rivers only, where neither water quality problems nor harmful to health effects are not expected. Consequently we could successfully avoid severe alkaline and heavy metal pollution of the Raba and Danube rivers - no harmful effects to the nature can be expected.
The Hungarian State’s priority aim is to keep the pollution plume inside the territory of the country, to localize the mud in the Marcal river bed and to prevent that pollution plume reaches the Danube River via Rába River and Mosoni Danube. In the area of the source of the pollution (in the neighbourhood of settlements Kolontar and Devecser, Veszprem county) the red mud covered cca. 800 hectars according to the estimations which will be neutralised by spreading out gypsum by agricultural airplanes. This will be followed by removal of the upper 2 cm of the contaminated soil in order to protect the water sources as well as to avoid the spreading away the dry red mud by wind.
Budapest, 7th of October 2010