Preliminary hydrogeological interpretation of the Aigion area from the AIG10 borehole data

The AIG10 borehole provided direct access to hydraulic conditions. The first results of two open-hole pumping tests and one artesian production test are presented. From the first pumping test in the conglomerates, a hydraulic conductivity of 10 −5-10 −4 m s −1 was derived and it was suggested that there is a closed hydraulic system bounded by the Aigion Fault zone and other faults farther north. A second pumping test, in the Olonos-Pindos limestones, showed artesian flow (water pressure of 0.5 MPa and flow of 1.9 × 10 −4 m 3 s −1). The transmissivity is about 4 × 10 −6 m 2 s −1. Below the fault zone, pressure and flux increased, suggesting karstic water-flow conditions. Water-pressure difference of more than 0.5 MPa between the hangingwall and the footwall provides evidence that the Aigion Fault zone acts as an impervious zone. An artesian production test for the interval 708-1001 m showed a fluid pressure of >1 MPa and natural flow of 1.5 × 10 −2 m 3 s −1. A transmissivity of 2-3 × 10 −4 m 2 s −1 was determined. A preliminary conceptual hydrogeological model, containing flow parameters and flow paths, is developed, based on data from AIG10 and other wells and springs.