Small-scale water quality monitoring networks

The monitoring of seawater physico-chemistry using automated buoys is well developed for large oceanic scales. Accessible and easy to handle small-scale monitoring buoys and land-based receivers are still missing in coastal water monitoring. River basins, reservoirs and estuaries are the most stressed aquatic environments as a result of their intensive use. These water bodies, and adjacent coastal waters, are priority candidates for continuous and reliable water quality monitoring. Environmental Agencies establish monitoring programs that involve water sampling and laboratorial analysis. Small-scale automated monitoring systems work with relatively low costs if simple materials and readily available technologies are used. We propose the development of a monitoring system that involves small plastic buoys/moorings with temperature and salinity probes, signal emitter/receptor devices, and Programmable Logic Controller (PLC) with wireless communication. The proposed technologies already exist, but need to be developed to work together in inhospitable environments as salt water and high temperatures. It is indicated for the continuous monitoring of shallow water bodies within coastal conservation units, municipal water reservoirs and even by environmental agencies in an upstream/downstream design to monitor water intake and effluents discharges from industries and water treatment plants. Private users may also be interested in installing the system if they are responsible for the maintenance of the water quality of coastal environments. Cheaper and efficient water quality monitoring is key to the building of meaningful time series that can be statistically treated to allow predictions of water quality changes.