Barcarena/PA +55 11 3217 6300 | www.sgwservices.com Investigation | - - PowerPoint PPT Presentation

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Oct 12, 2023 252 likes •411 views

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Review of Water and Effluent Management

Investigation | Remediation | Audits | Permitting | Consultancy

Alunorte Barcarena/PA

Environmental Consultancy and Engineering +55 11 3217 6300 | www.sgwservices.com

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✓ Independent Assessment of the Refinery Water and Effluent treatment management system. ✓ Focus on the intense rain event occurred on February 16th and 17th that caused flood at Barcarena region. ✓ This review is preliminary and the works are ongoing. ✓ The objective is to verify if the intense rain event resulted in environment contamination related to Alunorte leakages or operational and procedural failures.

Scope and Objectives

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224mm rain in 10 hours

✓ There was no overflow at the solid waste basins - DRSs ✓ There was a Flood in Area 45 - The rainwater leakage occurred by a cracked deactivated pipe. Visual inspections and soil pH measurements results did not identify environmental alterations. There was no overflow towards the Murucupi River. There are no evidences of environmental impacts in the river due to the deactivated pipe leakage. ✓ Untreated rainwater was discharged into the Pará River by the Canal Velho in order to avoid WWTP basins overflowing. The discharge also received alkaline effluents from the process and there was a pH control and neutralization during this discharge.

Rain events on Feb 16th and 17th

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Water Balance Simulation performed by SGW

(100 000) (80 000) (60 000) (40 000) (20 000) 20 000 40 000 60 000 80 000 1 2 3 4 5 6 7 8 9 1011121314151617181920212223242526

Basins capacity WWTP (m3) Hours

WWTP Basins Capacity

100 000 200 000 300 000 400 000 500 000 600 000 700 000 800 000 900 000 1 000 000 1 2 3 4 5 6 7 8 9 1011121314151617181920212223242526

Basins capacity DRS1 (m3) Hours

DRS1 Basins Capacity

100 000 200 000 300 000 400 000 500 000 600 000 1 3 5 7 9 11 13 15 17 19 21 23 25

Basins capacity DRS2 (m3) Hours

DRS2 Basins Capacity

Area 45 pumps stopped Discharge to Canal Velho

SGW performed a Water Balance simulation of the days16 and 17 ✓ WWTP basins volumes did not have capacity to handle the unusual rainfall event; ✓ DRSs capacities sufficient

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As the existing data was not enough for a precise analysis of the Alunorte’s contamination potential, SGW carried out a sampling in the environmental: Surface water (Para and Murucupi rivers), effluents and mining pipeline; Soil, Bauxite, Coal, Ashes, Red Mud. Well water from the Bom Futuro, Burajuba and Vila Nova communities Preliminary results indicate impact absence on water bodies and point to region’s natural anomalies (Al and Fe)* The metals results are n/d or below the legal levels in the community wells - except 1 spot (Al = 220 ppb - Standard 200 ppb).

*Master thesis – Multielementary Regional Geochemistry applied to the Human and Environmental Health Fields in the Continental Portion of the Leaf AS.22-X-D – Belém – Northeast Region of Pará – Volume I; Author: Eduardo Paim Viglio, Belém – 2008; Pará University – Geosciences Institute

Sampling

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✓ Leakage from Sump 45 is not sufficient to cause significant environmental contamination. ✓ Emergencial discharge into Canal Velho – mainly stormwater – no significant impact in the Pará river ✓ Volumes discharge x river flow ✓ There was no overflow at the solid waste basins - DRSs ✓ Environment Diagnostic and monitoring expansion. ✓ The metals results are n/d or below the legal levels in the community wells

except 1 spot (Al = 220 ppb - Standard 200 ppb) – source not clear

✓ Preliminary results yet, so far not indicating any significant impacts

Conclusions

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