Abstract: A method and apparatus are provided for conducting a microbiological process on a bulk material in which a quantity of the bulk material is loaded onto a waterproof lining forming part of a bio cell with a heat transfer arrangement below the quantity of bulk material or within its volume, or both. The moisture content of the bulk material is controlled by periodic or intermittent distribution of water into the bulk material in order to promote microbiological activity within the bulk material by means of microbes that may be either naturally occurring within the bulk material or may be selected and introduced into the bulk material according to a desired result. A leachate recovery installation collects leachate draining from the bulk material. The temperature within the bulk material is monitored and the temperature controlled in order to elevate or decrease the temperature thereof to approach a target temperature associated with enhanced microbial activity of microbes present within the bulk material.