TITLE:
Assessment of Aquifer Contamination in the Northeast of the Montevideo Department, Uruguay
AUTHORS:
Karina Pamoukaghlián, Elena Alvareda, Virginia Martinato, Valery Bühl, Paulina Pizzorno, Valeria Rodríguez, Elyana Muñoz
KEYWORDS:
Water Quality, Aquifer, Total Arsenic, Uruguay
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.6,
June
30,
2026
ABSTRACT: Increasingly frequent water scarcity conditions necessitate the implementation of alternative water sources to supply the Department of Montevideo. In order to identify a potential alternative source, a water quality assessment and potential contamination evaluation of the fractured aquifers in the northeast of the Department were conducted. These aquifers are composed of Paleoproterozoic rocks from the Montevideo Belt. Based on a previously conducted hydrogeological and hydrogeochemical study, 10 wells in a pilot area northeast of Montevideo were sampled for microbiological and nitrite analyses. Additionally, 10 samples from the same wells were analyzed at the Faculty of Chemistry to detect total arsenic concentrations in groundwater. The elevated nitrate concentrations, along with the absence of nitrites, indicate an oxidizing environment and persistent contamination, likely associated with diffuse sources such as septic systems and possibly also linked to the use of organic fertilizers. This situation, coupled with the detection of microbiological contamination (fecal coliforms and Pseudomona), highlights the high vulnerability of the fractured aquifer to human activities in an urban and peri-urban context. Regarding total arsenic (tAs) concentrations in groundwater, they do not exceed the WHO’s recommended limit of 10 μg/L, except for one value that slightly exceeds this limit. Although there are indications of contamination in the fractured aquifer studied, these studies should be continued to develop an appropriate remediation plan that would allow these aquifers to be used as an alternative source of drinking water.