Hydraulic Conductivity of a Geosynthetic Clay Liner to a Simulated Animal Waste Solution

Abstract

The potential use of a commercially available geosynthetic clay liner (GCL) as the primary hydraulic barrier for animal waste lagoons was evaluated on the basis of hydraulic conductivity (k) testing. The GCL was permeated under both aerobic and anaerobic conditions with both deionized water (DIW) and a simulated animal waste solution to determine the effect, if any, of the simulated solution on k of the GCL relative to k based on DIW. The chemical composition of the simulated solution was based on reported compositions for animal waste lagoons in Colorado. The k of the GCL increased only slightly (8%) on average when permeated with the simulated solution under anaerobic conditions relative to the k of 1.3 10-9 cm/s based on permeation with DIW, but increased by a factor of 4.2 on average when permeated with the simulated solution under aerobic conditions. The measured k values are shown to be consistent with those from other studies involving permeation of GCLs with various chemical solutions at the same ionic strength as that for the simulated animal waste solution used in this study. The practical implications of the results relative to regulations governing liners for animal waste lagoons in 12 states are discussed.