Construction of a protective dam to protect Hungarian villages from the toxic spill caused by the collapse of a metals factory dam was completed this week.
The new 620m long dyke cuts the village of Kolontár in two, protecting the largely unaffected zone to the south and the Devecser settlement further downstream.
A chemical, biological, radiological and nuclear Hazmat team has confirmed that there have been no further structural movements of the endangered section of the breached dam.
The National Disaster Management Directorate also said cracks in the dam wall had stabilised.
The new dyke has an average height of 2.75m and is situated between 200m to 300m downstream of the breached reservoir, whose wall burst on 4 October leaving the surrounding towns inundated with caustic red sludge.
Clean-up operation ongoing
Up to 700,000m³ of slurry – comprising iron and aluminium oxide – excaped from the reservoir owned by the Mal Alumina Plant, spreading across an area of 40km². The sludge’s high alkalinity triggered environmental concerns.
Gypsum and acetic acid treatments are still being used in the Marcal River, with around 250,000l of acetic acid used so far.
Water quality and air pollution are being continuously measured, with 11 air quality check points established at present. Workers involved in the clean-up operation have been warned by health authorities that red dust hanging in the air exceeds safe limits.
Work has also begun on an assessment of future requirements for the rehabilitation of contaminated agricultural areas.