Process for sampling contaminated ground water from bore-holes - using a pressure activated filter pipe integrated with the drill pipe at a known level

摘要

A process for obtaining water samples from bore holes is contaminated ground. The samples are identifiable as having come from a known (in depth) horizontal rock layer. After halting of the drilling ring at the required level, cleaning fluid is pumped down the hollow drill rod until it is clean. The drilling ring is then started again for a short period so that borings form a seal at a contraction around the drill rod (2), above the filter pipe (5). The cleaning fluid below the seal together with water from the surrounding strata is sucked into the inner channel (3) through the filter pipe (5). It is then sucked to the top in the normal manner for analysis. ADVANTAGE - The process is quicker and more reliable than previous methods and requires no additional mechanical equipment.