The impact of mining activities and heavy metal pollution in the Apuseni Mountains, Romania

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The impact of mining activities and heavy metal
pollution in the Apuseni Mountains, Romania
BALWOIS Conference 25, 29 May 2004 Ohrid, FY
Republic of Macedonia Conference on Water
Observation and Information System for Decision
Support

• Mihaela Serban, Graham Bird, Paul Brewer,
• Mark Macklin, Dan Balteanu

Romanian Academy Institute of Geography
University of Wales, UK Institute of Geography
and Earth Sciences
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MAIN METAL MINING EXPLOITATION IN THE APUSENI
MOUNTAINS

• River systems categories
• with historical mining activity, presently
  inactive
• with historical and present mining activity
• with opportunities for the opening of new
  exploitations
• with tailings dam accidents

U K R A I N E
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Data collection and laboratory methods
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Data collection and laboratory methods

• Surface water
• Filtered through 0.45 mm membranes
• Acidified with 50 HNO3
• Cd, Cu, Pb and Zn determined using ICP-MS

• River channel sediment
• Sediments collected from bar surfaces
• Air-dried for gt 72 hours
• Sieved through a lt 63 mm mesh
• Digested in 70 HNO3
• Cd, Cu, Pb and Zn determined using ICP-MS

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Environmental quality guidelines

• Provide a means of evaluating the magnitude of
  metal contamination relative to potential human
  health effects.
• Water quality guidelines
• based upon EU directive 75/440/EEC
• Sediment quality guidelines
• established by the Dutch Ministry of Housing,
  Spatial Planning and Environment
• Target value aim to keep concentrations near to
  or below these value
• e.g. 20 mg l-1 for Cu in surface water intended
  for consumption
• Imperative / intervention values risk to human
  health and remediation required if concentrations
  exceed this value
• e.g. 50 mg l-1 for Cu in surface water intended
  for consumption

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Aries and Certej catchments
Mialu tailings dam, Certej catcment
Upper Aries river valley
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Certej river basin a mining affected basin

• 78 km2 catchment containing the 40.05 km2
  Certej-Coranda mining concession.
• Mining history dating back to the Roman period.
• Current open-cast exploitation at Coranda with
  ore processed in Certeju de Sus.
• Two tailings ponds in the catchment Miresului
  (inactive) and Mialu (active).
• Historical tailings dam failure in 1971.
• 70 samples taken from 30 sample sites.

inactive tailings dam
1971 accident site
active tailings dam
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River Certej Cd in surface waters
River Certej Cd in river channel sediment
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Floodplain soils the Miresului pond
Distance from channel
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River Certej results summary

• Water and channel sediment quality degraded by
  mining activity, especially at Coranda.
• 100 and 93 of water samples exceed EU target
  and imperative limits respectively. Cd
  concentrations exceed the imperative value by up
  to 298 times.
• In channel sediments, As exceeds Dutch
  intervention levels at 100 of sample sites.
• Unlike sediment-metal concentrations, solute
  levels decrease with distance downstream.
• Statistically strong relationships (lt r2 0.72)
  between solute and channel sediment
  concentrations.
• Possibly suggests the importance of sorption /
  desorption reactions

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Aries river 51 sample sections (2002 2003)
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Rosia river, a mining affected tributary
Rosia Poieni quarry
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River Abrud Cu in surface water
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Aries river Cu concentration in surface water
(2002-2003)
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Aries river Cu concentration in channel
sediments (2002-2003)
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Exchangeable Cu hotspots
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Sasar vs. Aries metal concentrations (2002)
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Results summary

• Surface waters and channel sediments of Aries
  tributaries are severely affected by metal mining
  activity.
• Production of acid mine drainage (pH gt3.8)
• River Abrud suggests solute pollution is
  spatially limited.
• 99 reduction in solute Cu levels within 2 km of
  Bucium mine
• Solute As, Cd, Pb and Zn levels in the Aries
  comply with EU directive 75/440/EEC, despite
  polluted tributaries.
• Limestone rich geology facilitates high pH (7.3
  8.8), physical dilution
• Cu contamination in Aries downstream of the Valea
  Sartas.
• 93 reduction after 13 km, but still exceeds EU
  target value
• Cu levels exceed intervention values prior to
  Mures confluence, 90 km downstream of the last
  contaminated tributary
• Cu mined at Rosia Poienii
• 2003 water sediments higher than 2002 in the
  upper basin
• 2003 channel sediments higher than 2002 for all
  sites

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Mures river 14 sample sites
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River Mures Cu in surface water
River Mures Pb in river channel sediments
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Results summary

• Despite heavily polluted tributaries and urban
  areas, surface waters of the River Mures are not
  contaminated with Cd, Cu, Pb or Zn.
• Physical dilution and high aqueous pH (8.27
  9.38)
• As concentrations exceed target values at 2
  sites.
• Geology, urban pollution sources, higher pH of
  hydrolysis for As (XX)
• River channel sediments at 92 of sites exceed
  target values for either Cd, Cu, Pb or Zn.
• Increases in concentration downstream of mined
  tributaries
• As concentrations in channel sediment fall below
  target values at all sites despite higher
  concentrations in tributaries.
• Metal and As levels in waters and channel
  sediments in the River Mures do not exceed
  imperative / intervention values.