Slug test interpretation using Hvorslev
A “slug test” is a quick procedure you can do to open wells (“standpipes”) to get an estimate of the hydraulic conductivity of the ground. It involves applying a small pertubation to the standing groundwater level in a well, and monitoring its recovery back to pre-test conditions. The picture shown above is of a air-displacement slug test apparatus, where compressed air is used to momentarily pressurise the standpipe, the suddenly release the pressure and monitor the water level change with a logger. The classical document by Hvorslev in 1951 is a great paper, but if you are just wanting to do slug test interpretation, you have to wade through a bit of material to get to the pieces that matter. I also found that published methods and software that employ it are unnecessarily complicated, and there is a common error that often arises. I set out the rationale behind his method in analysing slug tests as a simple reminder to myself, and found its a useful document. You can access it here.