The Verso Energy stimulation process is localised to zones around the boreholes and limited by the low natural permeability of coal. Changes to groundwater are minimal because the nutritional amendment is very subtle, and involves balancing of the ratios of elements already present in the groundwater.
MCC is based on a natural biological process already occuring in the coal seam therefore only minimal amendment of the natural water chemistry is required. This does not see the seam water quality exceed stock water guidelines. Most groundwater analytes remain within drinking water standards.
No volatile organic compounds such as BTEX, PAH or phenolics are used or produced in the process.
Microbes used in the Verso process are derived from natural sources and are indistinguishable from the native coal seam biology without advanced DNA sequencing. The type used in the process have been approved for use in Australia by the Department of Agriculture Forestry and Fisheries.
Microbes are anaerobic which means they cannot survive in the presence of air. They pose no risk to plants, animals or humans. There is no genetic modification.
Microbes are limited by the same natural conditions that restrict proliferation of the natural biology. Without nutritional supplementation they will decline to background levels. There is no risk of uncontrolled biological growth.
The process can be stopped by withdrawing nutrition, air treatment, or the use of off-the-shelf water bore scale remover (biocide)
The ability to restored depleted CSG/CBM fields provides the option for operators to re-use their existing fields rather than develop new fields. Where sensitivities exist around development of gas fields on agricultural land, this could be a win for both landholders and gas producers.
Verso's microbial processes are not reliant upon natural geological fairways, therefore areas can be developed with greater consideration for existing high value land use. Projects can also be developed with greater focus on existing gas and power infrastructure, improving the commercialisation prospects of new projects.