Hydrogeochemical investigations in arsenic-affected aquifers in Argentina (La Pampa) and Inner Mongolia (Hohhot Basin) in partnership with Instituto de GeoquRmica, Buenos Aires and Hohhot Antiepidemic and Sanitation Station, Hohhot respectively.

Argentina: investigations in La Pampa Province of central Argentina have highlighted a large range of chemical compositions in groundwaters derived from Quaternary loess silt deposits but with some very high arsenic concentrations (<0.004 to 5.3 mg/L). More than 90% of the groundwaters studied have arsenic concentrations in excess of the WHO recommended limit. Other anion and oxyanion species (e.g. species of F, Se, B, V, Mo) are also present in high concentrations and often well correlated with arsenic. Salinity is also a problem in the area. Remediation of potable supplies derived from such aquifers is extremely difficult because of the combined problems of salinity and toxic trace elements.

Inner Mongolia: hydrogeochemical investigations of groundwaters in the Huhhot Basin, Inner Mongolia are ongoing.

On going work

Smedley, P L, Nicolli, HB, Barros, AJ and Tullio, J O. 1998. Origin and mobility of arsenic in groundwater from the Pampean Plain, Argentina. In: Water-Rock Interaction, Proc 9th International Conference on Water-Rock Interaction, Taupo, New Zealand, 1998, eds: Arehart, G B and Hulston, J R. 275-278, Balkema, Rotterdam.

An earlier part of the programme involved investigations of arsenic problems in groundwaters of Bangladesh and groundwater sampling was carried out in the western part of the country in February 1997 under this project. Subsequent investigations in Bangladesh are being carried out under a separate DFID-TC programme together with Government of Bangladesh (see the BGS Hydrogeology Group).

Tel: +44 1491 692319
Fax: +44 1491 692345
Email: P.Smedley@bgs.ac.uk