Reconstruction of an Acid Water Spill in a Mountain Reservoir

Abstract

The Olivargas Reservoir is located in a remote and scarcely monitored area in the Odiel River Basin (Southwest Spain) and is used for domestic, agricultural and mining water supplies. In contrast with highly monitored reservoirs, this paper explores the application of the CE-QUAL-W2 model, that was designed by Cole and Wells in 2005, to a poorly monitored reservoir and the utility of the results obtained. The model satisfactorily reproduced the water head measured continuously over three years, temperature (T), total dissolved solids (TDS), dissolved oxygen (DO) and pH measured bimonthly in a depth profile near the dam. A significant increase in TDS and decrease in DO and pH profiles were observed for four months, especially in the hypolimnion. The model reproduced changes in the parameters by assuming the occurrence of an acid water spill into the reservoir. A comparison of calculated results and measured TDS and DO prompted the conclusion that the spill consisted of approximately 3000 t of TDS (mainly sulfates) and 26 t of Fe(II) flowing into the reservoir for approximately 15 days at rates of approximately two and 0.02 kg/s, respectively.Water 2017, 9, 613 2 of 15 applications are based on a broad understanding of reservoir geometry and time-series data on flow, temperature profiles and chemical and biological quality.Many small reservoirs (<50 hm 3 ), however, exist in remote and mountainous areas. They supply water to small communities, and there is rarely accurate monitoring or complete datasets on their physical, chemical and biological parameters. For such communities, water resource management is just as necessary, but the application of the conventional W2 can be challenging and has yet not been explored.The present work describes the calibration of the W2 model for a small reservoir with scarce monitoring in the upper basin of the Odiel River (in Southwest Spain). This region is known for its mining activity, and water from the reservoir is used for domestic consumption, agriculture and mining. As the only form of surveillance, a depth profile of temperature (T), electric conductivity (EC), dissolved oxygen (DO), pH and oxidation-reduction potential (ORP) was taken every two months close to the dam of the reservoir from June 2009 to December 2012. All these data were obtainable by the user without permanent stations or monitoring programs. Besides, an anomalous EC, DO and pH values were detected in one surveillance campaign and were attributed to a possible mining spill.For the reconstruction and evaluation of a possible pollution event, a W2 model was built and calibrated with the data from the bimonthly profiles. In contrast with the highly detailed models on highly monitored reservoirs, this paper explores the application of W2 to a poorly monitored reservoir and the utility of the results obtained.

Reservoir Hydrologic Routing for the Hydrodynamic of Al-Manzala Lake, Egypt

“…Similar studies on numerical models for lake environments have also been conducted by [6], [7], and [8]. This was stated by [9].…”

Novel Technology for the Removal of Brilliant Green from Water: Influence of Post-Oxidation, Environmental Conditions, and Capping

“…Investigating the effect of pH is a matter of interest for the pollution control protocol, as the earth water reservoirs depict diverse acidity. 37 BG solution was found to have different absorbances (with similar ∼λ max = 623 nm) depending on the pH. The BG solution was green, blue, and cyan (with suspending sulphur as colloid) at acidic, neutral, and alkaline pHs, respectively.…”

“…Investigating the effect of pH is a matter of interest for the pollution control protocol, as the earth water reservoirs depict diverse acidity . BG solution was found to have different absorbances (with similar ∼λ max = 623 nm) depending on the pH.…”

Factores condicionantes de la acidificación de embalses por lixiviados mineros en la Faja Pirítica Ibérica

“…No obstante, se observa una gran dispersión de las concentraciones (Fig. 5) debida a: 1) La dilución producida durante los periodos de fuertes avenidas y, por el contrario, mayores concentraciones de los aportes durante los periodos secos, 2) La existencia de procesos de estratificación térmica durante la primavera y verano, que provoca diferencias de calidad entre el epilimnion (capa superficial) e hipolimnion (capa profunda), de forma que en este último se puede agotar el oxígeno disuelto y alcanzar condiciones reductoras, 3) La concentración por evaporación durante el estiaje en la capa superficial y, 4) La variación en los aportes de contaminantes de origen minero, como el empeoramiento comentado en el embalse del Sancho en los últimos años (Cánovas et al, 2016), o vertidos accidentales de aguas ácidas (Jofre-Meléndez et al, 2017). Las concentraciones habituales de elementos de origen minero en los tributarios de los embalses afectados por AMD son muy superiores a las que se tienen en los embalses (DGOHCA, 1996;ACUAES, 2010;.…”