This document specifies a method for the determination of the microbiological resistance of geosynthetics by a soil burial test. NOTE Experience and exhumation of geosynthetics which had performed successfully, in some cases for more than two decades, indicate that geosynthetics made out of synthetic materials are generally resistant against microbial initiated decay. It can therefore be expected that most of these products commercially available at the present time will pass the soil burial test successfully and it is probably not necessary to submit them all to this test independent of their function. However, if the requirements for appropriate functioning of the geosynthetics demand proof of microbiological resistance or if they are manufactured from newly developed polymers whose resistance is in any doubt, the soil burial test should be performed.