On February 17, during the heavy rains that started the day before, and periodically between February 20 and 25, Hydro used a channel called Canal Velho to discharge rain water, with treated pH, from the factory to the Pará River. The water had its pH treated at the entrance of the channel, before being released and then mixed with the water from the effluent treatment station and with the surface waters of the Albras aluminum plant.

The rainwater in the refinery area may contain bauxite dust and traces of caustic soda, but the water was not in contact with the bauxite waste deposit areas.

External review to be completed in the first week of April

"Firstly, it is important to emphasize that we have no evidence of leakage or overflow from our bauxite waste deposit areas. We released rainwater from the factory area. The launch was made as a controlled measure, which we communicate to SEMAS, the state environmental agency, "says President and CEO Svein Richard Brandtzæg.

He adds that Hydro, based on collected water samples, has no evidence that the controlled release has caused any negative environmental impact.

"We are awaiting the internal task force report, as well as SGW Services' independent external environmental review, which will be presented in the first week of April," says Brandtzæg.

He emphasizes that Hydro is committed to establishing a complete overview of the facts and that the company's main focus now is to protect and ensure that people inside and around the factory feel safe and protected.

Notified state environmental authorities

Canal Velho is a canal, adjacent to the Alunorte water treatment plant, which is also occasionally used to discharge water separated from the bauxite slurry that is transported by the pipeline from Hydro's bauxite mine in Paragominas to Barcarena.

The controlled release of treated rainwater through this channel was made to relieve the water treatment plant during heavy rain. Discharges of rainwater treated on February 17 and periodically between February 20 and February 25 are not covered by the current license. Alunorte notified the Pará environmental authority, SEMAS, twice during the referred situation. Local communities were not informed when rainwater was discharged into the Pará River.

The channel had been used before to discharge rainwater in extreme precipitation events, the last time in May 2017. SEMAS was also notified after that event.

pH treated before discharge

The water had its pH treated at the entrance of the channel, before being released and then mixed with treated water at the effluent treatment station. Rainwater in the refinery area may contain bauxite dust and traces of caustic soda.

Channel usage and notifications are part of ongoing internal investigations and independent external review.

History

• In just 12 hours during February 16-17, the city of Barcarena, which houses Hydro's Alunorte alumina refinery, was hit by extreme rainfall, flooding the region
• Hydro commissioned the Brazilian environmental consultancy SGW Services to carry out an independent review of the water treatment and effluent management systems at the Alunorte alumina refinery
• The independent environmental review is part of the actions announced by Hydro in response to Alunorte's challenging situation, where the authorities requested several measures due to concerns that the period of extraordinary rains would lead to harmful spills in the surrounding areas, including the neighbor Pará River.
• Among the measures taken by federal, state and local authorities, there was a determination that Alunorte reduced production by 50% and suspended the operations of the Solid Waste Deposit 2 (DRS2)

Facts about the situation at Hydro Alunorte