In this paper the use of ER measurements in soils in the context of biocementation, is investigated considering its use as an indicator of treatment efficiency measured trough the presence of biocement, or to provide information about the presence of chemical by-products during or after final washing operations. The electrical resistivity of a slightly biocemented sand was analyzed on a laboratory scale test conceived to reproduce field measurements conditions such as varying degrees of saturation and the presence of chemical by-products in the pore fluid. The results confirmed that, independently from the degree of saturation, the nature of the pore fluid was the parameter that affected most the electrical resistivity measurements, and the presence of calcium carbonate affecting soil structure was detected only after removal of the treatment by-products by a complete final soil washing using water. From a practical point of view this non-destructive technique is more adequate to be used mainly at the end of the treatment, to check that complete soil washing has occurred, rather than checking the presence of bio-cement specially if the amount precipitated is not very high as it was the case of the tests performed.