QICS (Quantifying and monitoring environmental impacts of geological carbon storage) was a program funded by the Natural Environment Research Council (NERC), with support from the Scottish Government (May 2010 - December 2014) with two objectives. Firstly, to assess if any significant environmental impact would arise, if a leak from sub-sea, deep geological storage of carbon dioxide occurred. Secondly, to test and recommend tools and strategies for monitoring for (or assuring the absence of) leakage at the sea floor and in overlying waters. This data set provides a short overview of the novel experimental procedure - a world first leakage simulation in the natural environment and describes the experimental set up, sampling strategy including both temporal and spatial details. The data set consists of a pdf containing a text based project and experimental overview, a table outlining the temporal evolution of the experiment, including site selection, set up, baseline, impact and recovery phases and a diagram outlining the spatial sampling strategy. This data set contains an overview document collated by Plymouth Marine Laboratory. This provides the context for a number of specific related QICS datasets submitted to the UKCCS data archive, covering a range of geological, chemical and ecological information. QICS project website: www.bgs.ac.uk/qics/home.html. Blackford et al., 2014. Detection and impacts of leakage from sub-seafloor deep geological carbon dioxide storage. Nature Climate Change 4, 1011-1016. DOI: 10.1038/NCLIMATE2381. Taylor et al., 2015. A novel sub-seabed CO2 release experiment informing monitoring and impact assessment for geological carbon storage. Int J Greenhouse Gas Control. DOI:10.1016/j.ijggc.2014.09.007.