Notable case, Minas de Riotinto, Andalucía (Huelva), Spain
Río Tinto (Riotinto mining district)
A red river at pH 2–2.5, loaded with iron and metals, draining the Iberian Pyrite Belt, mined for about 5,000 years. It is the world's reference case for acid mine drainage.
At a glance
- Status
- Not addressed
- Media
- surface water, sediment, soil
- Kind of site
- mining
- Area. The river is about 100 km long and keeps its red colour for some 50 km.
Contaminants
Status
Not addressed
All mining stopped in 2001; in February 2016 Atalaya Mining restarted copper production. The river stays at pH 2–2.5. It is not clear how much of the acidity is natural and how much is due to mining.
Story
The sulphide deposits of the Sierra Morena were worked by Tartessians and Iberians from about 3000 BC, then abandoned and rediscovered in 1556. The Spanish state resumed mining in 1724; in 1873 the Río Tinto Company was formed, which took output to its peak in 1930 and came to employ up to 20,000 people. Copper mining ended in 1986, gold and silver in 1996.
Oxidation of pyrite produces sulphuric acid, which carries iron and other metals into solution. The deposits outcrop and oxidise naturally too, but mining greatly increased the exposed surfaces. The river stays acid down to the Huelva estuary. Extremophile bacteria live in its water, studied as a model in the search for life on Mars.
On the river terraces and tailings an endemic heather, Erica andevalensis, grows wild; researchers in Seville have studied it as a candidate for revegetating these soils.
Timeline
- 1724The Spanish state resumes mining.
- 1873The Río Tinto Company is formed.
- 1986Copper mining ends.
- 2001All operations stop.
- 2016Atalaya Mining restarts copper production.
Plants and fungi at this site
PhytoremediationProposed
Erica andevalensis
Study by the University of Seville and IRNAS-CSIC on wild plants from the Tinto and Odiel basins and the mining areas of Baixo Alentejo: cryo-scanning electron microscopy of leaves, stems and roots to see where the plant holds metals. Not a remediation trial, but the basis for proposing the species for revegetation.
Outcome The plant blocks lead and iron at root level; it cannot compartmentalise copper. The authors judge it suitable for revegetating polluted soil. The CORDIS note gives no numbers.
- Andalusian researchers prove the efficiency of Huelva-grown shrub to recover polluted soil, cordis.europa.eu, 2009
From the literature
Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.
Plants
- Pteris vittataChinese brake fernEvidence: field
- Agrostis capillarisCommon bentEvidence: field
- Cannabis sativaIndustrial hempEvidence: field
- Festuca rubraRed fescueEvidence: field
- Populus albaWhite poplarEvidence: field
- Ricinus communisCastor beanEvidence: field
Fungi
- Funneliformis mosseaeEvidence: greenhouse
- Rhizophagus irregularisEvidence: greenhouse
- Aspergillus nigerBlack mouldEvidence: laboratory
- Fomitopsis pinicolaRed-belted conkEvidence: laboratory
- Mucor circinelloidesEvidence: laboratory
- Agaricus bisporusButton mushroomEvidence: laboratory
The rest are on the contaminant pages.
Nearby
Sources
- Rio Tinto (river), Wikipedia, 2026
- Andalusian researchers prove the efficiency of Huelva-grown shrub to recover polluted soil, CORDIS, European Commission, 2009
Draft compiled from public sources, not yet reviewed.