A Novel Toolbox for Development of a Groundwater Health Index

Groundwater is a vital source of drinking water both in New Zealand and globally. Although groundwater represents a small proportion of the global water, it is a predominant source of drinking water. The perception, often, is that groundwater is a pristine, sterile environment. There are, however, a vast array of organisms thriving under our feet. These complex ecosystems protect our groundwater by removing contaminants that enter the groundwater through anthropogenic activities on the surface. There is however, as with all things a balance to maintain and there is a point which tips the balance. In these environments this can mean a drinking water is no longer protected from contaminants.

Current methods for assessment of the quality of groundwater are reactive; tests taken at point source that indicate a past problem. Our research is aimed at gaining a better understanding of these vital ecosystems and how they respond to contaminants in order to develop a proactive method of assessing groundwater health. The novel toolbox we are developing will assess the presence or absence of keystone species (micro and macro) to give a better picture of the health of the groundwater ecosystem and how it is able to protect the water we drink. We are using cutting edge technologies to develop the toolbox due to the inherent difficulties of sampling below the ground.

We will present our findings so far, identifying key microbial groups present in groundwaters of differing chemistries and changes occurring both spatially and temporally. This is the first step towards a groundwater health index similar to the MCI for surface waters.