Natural and anthropogenic features influencing water quality in NE Buenos Aires, Argentina.

GALINDO, GRISELDA; SAINATO, CLAUDIA; DAPEÑA, CRISTINA; FERNANDEZ TURIEL, JOSÉ LUIS; GIMENO, DOMINGO; POMPOSIELLO, MARIA CRISTINA; PANARELLO, HECTOR

Mar del Plata, provincia de Buenos Aires

Congreso; XXXII IAH & VI ALHSUD ?Groundwater and Human development?; 2002

AIH , AIH-GA y ALHSUD

This work study the water quality of the Pergamino River watershed in the Undulated Pampa in the northeast of the Argentinean Province of Buenos Aires. Temperature, pH, specific conductivity, Na, K, Mg, Ca, SO42-, Cl-, HCO3-, NO3-, Si, Ag, Al, As, B, Ba, Be, Br, Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Ni, P, Pb, Se, Tl, U, V, Zn, and the d18O y d2H isotope ratios were monitored in eighteen sampling stations. Groundwater and surface water are of sodium bicarbonate type, evolving to sodium sulfate-chloride type in the case of surface water. Natural processes related to the seasonal alternation of humid and dry periods (precipitation and evapotranspiration), and the ion exchange processes during water-rock interaction are the main factors influencing water quality, especially in relation with the water salinity. Point pollution sources (septic wells and other domestic effluents) induce the increase of nitrate concentration. On the other hand, pH, NO3-, Al, As, B, Fe, and Mn exceed the respective Argentinean reference thresholds in different sampling stations for human drinking water, B, Mo, U, and V for irrigation, and V and Zn for cattle drinking water.