Environmental legislation such as the EU Water Framework Directive is providing a significant impetus towards increased monitoring of natural waters. The widespread availability of autonomous, field deployable systems which can provide long-term, reliable, high frequency data on key water quality parameters via wireless communications would allow a significant improvement in our ability to monitor the quality of our natural water resources. An autonomous sensor for the analysis of a key nutrient, phosphate, in water has been developed by National Centre for Sensor Research (NCSR) researchers in Dublin City University. This sensor incorporates microfluidic technology, colorimetric chemical detection, and wireless communications into a compact and rugged portable device. The prototype system has been successfully deployed for extended periods at Osberstown Wastewater Treatment Plant, Co. Kildare, and at Swords Estuary, Co. Dublin to monitor phosphate levels over periods of up to several months. Current work is focused on the commercialisation of the prototype phosphate analyser. This work is being performed in collaboration with EpiSensor Ltd., a Limerick based SME with expertise in wireless communications, sensor design and data collection systems. The next generation phosphate system will be linked with EpiSensor’s reliable and secure ‘sensor to database’ or SiCA platform. All major components of the analyser have been evaluated and redesigned with a view to reducing cost, power consumption and size, while maintaining sensor accuracy and reliability. The commercial system mass and internal volume have both been reduced by a factor of 7 compared with the prototype system, while component costs have been reduced by a factor of 10. GSM communications on the prototype were replaced with EpiSensors ultra low power ZigBee radio. The system uses 20μl of reagent per reaction cycle and can carry out approximately 1400 measurements using a single lithium battery. The result is a low cost, low power and portable phosphate analyser. The system has been successfully deployed for short term trials at Swords Estuary, Co. Dublin.