title: Surface water monitoring in the mercury mining district of Asturias (Spain).
abstract: Systematic monitoring of surface waters in the area of abandoned mine sites constitutes an essential step in the characterisation of pollution from historic mine sites. The analytical data collected throughout a hydrologic period can be used for hydrological modelling and also to select appropriate preventive and/or corrective measures in order to avoid pollution of watercourses. Caudal River drains the main abandoned Hg mine sites (located in Mieres and Pola de Lena districts) in Central Asturias (NW Spain). This paper describes a systematic monitoring of physical and chemical parameters in eighteen selected sampling points within the Caudal River catchment. At each sampling station, water flow, pH, specific conductance, dissolved oxygen, salinity, temperature, redox potential and turbidity were controlled "in situ" and major and trace elements were analysed in the laboratory. In the Hg-mineralised areas, As is present in the form of As-rich pyrite, realgar and occasionally arsenopyrite. Mine drainage and leachates from spoil heaps exhibit in some cases acidic conditions and high As contents, and they are incorporated to Caudal River tributaries. Multivariate statistical analysis aids to the interpretation of the spatial and temporary variations found in the sampled areas, as part of a methodology applicable to different environmental and geological studies.
authors.affiliation: Departamento de Explotación y Prospección de Minas, Universidad de Oviedo, ETS Ingenieros de Minas, Independencia, 13 E-33004 Oviedo, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: Loredo
authors.forename: María Dolores
authors.initials: MD
authors.lastname: Petit-Domínguez
authors.forename: Almudena
authors.initials: A
authors.lastname: Ordóñez
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Galán
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Fernández-Martínez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Alvarez
authors.forename: María Isabel
authors.initials: MI
authors.lastname: Rucandio
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D007220:Industrial Waste; D008628:Mercury / Q000032:analysis; D008906:Mining; D045483:Rivers; D013030:Spain; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D008628:Mercury