Case history of leakage from a surface impoundment : Daniel, D E; Trautwein, S J In: Seepage and Leakage from Dams and Impoundments (paper to the symposium, Denver, Colorado, 5 May 1985) P220–235. Publ New York: ASCE, 1985

Abstract

A manufacturing company constructed a 48-acre (19 hectare), unlined surface impoundment at a site in northern Texas to store wastewater. The site is underlain by unsaturated, alluvial soils. An investigation of groundwater conditions beneath the pond, beginning in 1980, showed that a large mound of contaminated groundwater was perched above the aquifer. A number of finite element analyses were performed in which the hydraulic conductivities of the soil strata, as well as other soil properties, were adjusted until the calculated dimensions of the mound of contaminated water matched the known dimensions. The hydraulic conductivities that were needed to achieve good agreement between computed and measured groundwater conditions were, for some of the strata, several orders of magnitude higher than values obtained from laboratory permeability tests. A limited number of field permeability tests at shallow depth yielded hydraulic conductivities which agreed fairly well with the values from the finite element analyses.