Sampling for organic micropollutants on a regional scale is from existing public supply or production boreholes. These give good samples for analysis but they will be of mixed waters and may not indicate the true occurrence of organic compounds in the groundwater. The most widely applicable groundwater sampling methods from open observation boreholes in the UK are based on submersible pumps. Several systems are now in use but all have drawbacks when used for organic micropollutant sampling. The present systems, particularly when used in conjunction with straddle-packers, are suitable for studies of inorganic groundwater quality or organic pollution at concentrations above about lmg1-1. There are increased difficulties, however, when sampling for trace organic contaminants below concentrations of 1μg1-1 because of the ease of cross-contamination by the organic materials so prevalent in our environment. Great care has to be taken during sampling to minimize the cross-contamination.