Although phosphate is a critical nutrient involved in estuarine productivity, it is also a well-known contaminant of surface and ground water. This contamination can have significant effects in sensitive areas such as the terrestrial aquatic interfaces (TAIs) where the flux of nutrients can change over a relatively short period of time leading to hypoxia and the formation of harmful algal blooms. Researchers and other stakeholders have not been able to adequately monitor these potentially dangerous nutrient fluctuations because of limitations in the monitoring equipment currently available. This knowledge gap will be addressed with the development of a phosphate monitoring system that is robust, accurate and capable of making frequent measurements. Our approach is to adapt cutting edge technology from different aspects of instrument development and integrate them into a micro-fluidic based platform. With a micro-fluidic based system, the resulting device will be extremely portable and require minimal resources for long-term operation. In Phase I of this project the individual components of the instrument will be developed and tested for performance. These components include a specially designed filtration system and will allow the instrument to operate in high sediment conditions which is novel for this type of system. Other components include a unique module to remove chemical interferents and an optical sensing module. These components will be integrated to form the Phase I instrument. Parties from the private sector that would be interested in the development of the proposed instrument include environmental researchers in both academia and in industries that must conduct continuous water/process monitoring. Ultimately, we believe that the proposed product is both highly marketable by and has a high likelihood of attracting further funding from large instrument companies already involved in water monitoring in a variety of situations.