Construction of new basins for water storage in Alunorte
We aim to bring Alunorte up to a new environmental standard. After the rainfall in February 2018, we have been implementing and working with several upgrades to the plant:
- We have increased the water basin capacity by 350% (completed)
- We will increase the capacity of the water treatment facility by 50% (under construction)
“Hydro is committed to making Alunorte the industry benchmark – the best in terms of operational performance, technology, social dialog and environmental footprint.”
— Hydro CEO and President Svein Richard Brandtzæg, Hydro Capital Markets Day, 29 November
It’s the amount of rain that determines the required water treatment capacity. An estimated 80% of the water safely collected and treated at Alunorte is rainwater – coming either from the refinery area or from the rainwater basins of the bauxite residue deposits. Only about 15% of the water that passes through the water treatment system is water stemming from the production of alumina.
The water needed for alumina production remains fairly constant whether we produce alumina at 50% or 100% plant capacity. With the new water treatment capacity, Alunorte will be able to treat the rainfall anticipated in this region following a trend of more extreme weather.
Operational improvements are at an advanced stage at the refinery. The three new basins that will increase the water storage and capacity of treatment are in the final stage of construction. By 2020 Alunorte will have invested BRL 675 million in improvements in its systems for receiving, controlling, pumping and treating water. In addition to the new basins, construction will include new pumping systems and water pipes, new instruments for automation and control, new cameras for monitoring the basins and a new water treatment facility.
Alunorte has also acquired new vehicles such as ambulance, fire truck and pickups with gyro flex and speakers. The refinery is committed to making its procedures even more secure and robust, so the Emergency Response Plan was reviewed and, among other improvements, an Emergency Support Plan for Communities was created, structured to prepare the internal teams, authorities and communities to deal with emergencies involving Alunorte operations.
One of the items of the plan is the establishment of the Community Environmental Emergency Brigade, which includes 16 representatives, residents of the communities of Itupanema, Vila Nova, Bom Futuro, Jardim Cabano, Pioneiro, Laranjal, Murucupi, Burajuba and Água Verde. Community brigades were hired and trained to act in emergency situations at the plant. The effectiveness of the improvements in the procedures is evaluated through emergency simulations with participation of internal teams, authorities and the community.
See the video about the improvements implemented at Alunorte through December 2018:
“With the new storage and pumping capacities, available in December 2018, there will be no need to use the old channel to drain excess rainwater, considering rainfall similar to that which occurred on February 16 and 17, 2018, as well as for rains with return periods equal to 10,000 and 5,000 years, with duration of 12 and 24 hours, respectively. Upon completion of the installation of the new ETEI [the Industrial Wastewater Treatment Plant] unit, in May 2019, there will be an increase of approximately 50% in wastewater processing capacity, which will go from 9,500 m3/h to 14,000 m3/h. When the new capacity is considered, the outflow generated by the refinery will represent 15% of the maximum capacity of the ETEI.”
— Technical-scientific opinion by ATECEL and UFCG (Federal University of Campina Grande, Brazil)’, evaluation of Alunorte’s storage, pumping and wastewater treatment systems, November 26, 2018
In a study of November 26, 2018, professors from the Federal University of Campina Grande, Brazil, showed through computer simulations that the improvement are correctly designed and ensure the safety of Alunorte’s operations. In the study, the improvements were tested to sustain extreme levels of rain that are probable to occur only once in 10,000 or 5,000 years. The simulations were done for continuous rainfall over 12 and 24 hour- periods. The results show that Alunorte would safely manage both these levels of extreme rainfall, without the need to use the water channel ‘Canal Velho’ to release excess rainwater.
Read more in Hydro’s press release: ‘Brazilian expert study shows no overflow from Alunorte’s residue deposit areas during the rainfall in February 2018’