Correlation of Laboratory Analyses of Soil Properties and Infiltrometer Seepage from Drainwater Evaporation Ponds

Abstract

ABSTRACT CONSTRUCTION of drainwater evaporation ponds for disposal of subsurface drainage effluent has raised concern over the extent to which seepage from these ponds affect shallow groundwater. Estimates of seepage rates based on laboratory measurements of soil properties are considered through comparison of results of laboratory and field measurements at 90 sites within a pond. Lognormal means of field measured seepage rates were over six times larger than associated means of hydraulic conductivities measured in the laboratory. The discrepancy can be attributed to potential compaction of extracted cores used in the laboratory, layering of pond soils contained within infiltrometers, and hydraulic gradients greater than unity in pond soils. Of the laboratory measurements considered, field seepage rates were most closely correlated with permeameter-based measurements of hydraulic conductivity and the clay content of the soil. Due to the number of factors involved in correlating results of laboratory and field experiments with respect to soil heterogeneities and sample consolidation, additional work in this area is necessary to validate use of laboratory analyses for estimates of seepage in the field.