Research article DEPLOY: a long term deployment of a water quality sensor monitoring system Anto ´in Lawlor NCSR, Dublin City University, Dublin, Ireland Javier Torres and Brendan O’Flynn Tyndall National Institute, Cork, Ireland John Wallace IDS Monitoring, Co Clare, Ireland, and Fiona Regan Marine and Environmental Sensing Technology Hub, Dublin City University, Dublin, Ireland Abstract Purpose – DEPLOY is a successful technology demonstration project showing how state of the art technology can be implemented to achieve, continuous, real-time monitoring of a river catchment. Design/methodology/approach – The DEPLOY system is a wide area network of monitoring stations delivering data in near real-time. The demonstration sites chosen are based in the River Lee, which flows through Ireland’s second largest city, Cork. The sites include monitoring stations in five zones considered typical of significant river systems and demonstrate the versatility of the technology available. Data were collected from stations at pre-programmed intervals and transmitted to the DEPLOY servers either by short range ISM band radio or directly via the GSM GPRS network. The data were then processed and made available in a controlled manner at www.deploy.ie Findings – The project demonstrates the capability of multi-sensor systems to remotely monitor temporal and spatial variations in water quality, through the identification of short-term events. A system like DEPLOY could be used as a decision support tool by regulatory bodies in managing our aquatic environment with the potential to cut overall monitoring costs and provide better coverage representing long-term trends in fluctuations of pollutant concentrations. Originality/value – The demonstration of a truly heterogeneous water quality monitoring networked system was one of the first of its kind in Ireland. Based on the collected data DEPLOY can provide recommendations for water quality monitoring systems from various perspectives, technical, operational and strategic. Keywords Water quality, Sensors, Monitoring systems, Rivers, Ireland Paper type Research paper Introduction to continuous monitoring Within Europe, monitoring of water bodies will increase over the coming years, in response to the Water Framework Directive (WFD), and globally owing to pressure from climate change and other pressures. Legislative controls such as the WFD aim to ensure clean, sustainable water supplies in the EU through the achievement of “good chemical and ecological status” for all groundwater, rivers, lakes, coastal and other water bodies throughout Europe by 2015, with “no deterioration” accepted in existing water quality status (EC, 2000). A large part of the compliance requirement to “good chemical and ecological status of both surface and groundwater” is based on chemical monitoring data. Currently, the most commonly used method for measuring levels of chemical pollutants is the physical collection of a spot/grab sample that is then analysed back in the laboratory (Yang et al., 2002). This has a number of disadvantages, including cost, and the delay in obtaining results as a consequence of time needed for laboratory analyses, which in any case only shows a snapshot of the measured variable at the time of sampling. Since levels of pollutants can vary temporally and spatially, this is an important factor as fluctuations associated with episodic events could be missed, or conclusions could be drawn on the basis of what may only be transitory high levels (Allan et al., 2006; Dworak et al., 2005; Wagner et al., 2000). When persistent fluctuations occur, it is likely only to be detected through continuous measurements, which have The current issue and full text archive of this journal is available at www.emeraldinsight.com/0260-2288.htm Sensor Review 32/1 (2012) 29–38 q Emerald Group Publishing Limited [ISSN 0260-2288] [DOI 10.1108/02602281211197125] The authors wish to acknowledge the support of the Environmental Protection Agency and the Marine Institute who funded this work through the Science, Technology, Research and Innovation for the Environment (STRIVE) Programme 2007-2013. 29