Journal of Chemical, Environmental and Biological Engineering 2021; 5(2): 62-68 http://www.sciencepublishinggroup.com/j/jcebe doi: 10.11648/j.jcebe.20210502.14 ISSN: 2640-2645 (Print); ISSN: 2640-267X (Online) Disposition of Wastewater from Oil Wells in Venezuelan Savannahs and Their Effects on Percolation Waters Danilo López-Hernández 1 , Oswaldo Vallejo-Torres 2 , Fernando Liendo 3 , Juan Urich 4 , Carmen Hernández 5 1 Center for Applied Ecology, Institute of Zoology and Tropical Ecology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela 2 Graduate Deanship National Experimental University of the Western Plains, Guanare, Venezuela 3 Venezuelan Institute of Technology for Petroleum, Caracas, Venezuela 4 Graduate Course in Ecology, Faculty of Sciences, Central University of Venezuela, Caracas, Venezuela 5 Environmental Engineering, National Experimental University Marítima del Caribe, Catia la Mar, Venezuela Email address: To cite this article: Danilo López-Hernández, Oswaldo Vallejo-Torres, Fernando Liendo, Juan Urich, Carmen Hernández. Disposition of Wastewater from Oil Wells in Venezuelan Savannahs and Their Effects on Percolation Waters. Journal of Chemical, Environmental and Biological Engineering. Vol. 5, No. 2, 2021, pp. 62-68. doi: 10.11648/j.jcebe.20210502.14 Received: September 2, 2021; Accepted: September 17, 2021; Published: November 5, 2021 Abstract: In the eastern Venezuelan Llanos, the drilling fluids composed of wastewater (WW), accompanying hydrocarbons and wastes from oil activity are deposited in a system of waterproofed pits. Later, by means of siphons, the hydrocarbon phase of the WW is separated. WW are typically very salty and contain suspended and dissolved solids, residual hydrocarbons, and chemicals used in hydrocarbon extraction. So they are transported to a pit and treated with a flocculating agent and lime. Once carried out, the flocculation-coagulation operation and pH correction, WW are released to the environment. The savannas where the treated water are irrigated, in addition to the oil operation, present an intense agricultural and livestock activity, and rest on aquifers that are partially replenished with the percolation waters near the treatment pits. Therefore, this research will aim to analyze: i) the levels of soluble salts and heavy metals in the percolation waters collected in lysimeters located in savanna soils adjacent to oil wells after irrigation with WW treated with flocculating agents, and ii) the estimation of time which these salts take to be dislodged from the soil. The waters from the lysimeters did not report high levels of soluble aluminum or heavy metals since their soluble forms were precipitated by liming. Likewise, the coagulation-flocculation process removed the high levels of barium from the untreated WW. The contributions of sodium and calcium from the WW have a liming effect on the acidity of these soils. The sodium levels contributed by the WW could represent an environmental risk, fortunately, the good internal drainage of these sandy Ultisols allows their removal. Studies with lysimeters showed that the percolation waters of areas irrigated with flocculated water have a similar sodium content to that of control lysimeters six months after treatment. Keywords: Sodium, Barium, Aluminum, Contamination, Savannah 1. Introduction The oil industry, through its different activities, uses and generates a set of substances, many of them potential agents of environmental deterioration, so that the contamination of terrestrial ecosystems by oil or its derivatives is an event that can occur with certain frequency, either by the disposal of waste in the environment, or accidentally due to the rupture in the different containers of oil and their derivatives [1-6]. In oil well exploitation areas, disused materials and wastes are generated from oil exploration, production, refining and commercialization activities, which due to non-compliance with environmental law, become environmental liabilities. These liabilities degrade the physical, natural and social environment, causing risks to health and ecosystems [7-10]. Hydrocarbon pits are excavations carried out in the soil,