Water quality monitoring is carried out for a number of reasons. Businesses with environmental licenses are required to monitor discharges to water or in the receiving environments to demonstrate compliance with license conditions. Government departments and research organizations monitor water to understand how activities in a catchment affect water quality to inform water quality models, to detect trends in water quality or events.
Monitoring of water can be undertaken manually by sampling or in-situ analysis with handheld meters, through to automated samplers (ranging from simple first flush to complex event-based samplers), all the way to continuous sensing and monitoring systems providing real-time understanding of water quality.
IoT-mediated monitoring allows for substantial operational, technical, financial and environmental benefits. Its ability to detect issues in real time to allow rapid response is a valuable addition to any water quality monitoring program. Currently, the range of sensors available limits the number of parameters that can be continuously sensed.
But this list is growing as sensor technology evolves. Sensors for temperature, pH, pressure, salinity, chlorinity, dissolved oxygen, algal blooms and chlorophyll, turbidity, salinity, conductance, TDS and TSS, are readily available. The cost of these sensors varies substantially, as do the maintenance and calibration requirements.
On one end of the spectrum, we have IoT-based water quality monitoring. High-performing, cost-effective, real-time, deeply insightful, but a limited number of water quality parameters that can be measured.
On the other end of that spectrum, we have water sampling for lab analysis. This approach is expensive, logistically constraining, and extremely reactive (results can take weeks to be known). But it can be applied to any water quality parameter known.
In the middle of that spectrum, we find water sampling for in-field analysis. A water scientist or environmental engineer goes on-site to sample and carries out analysis on the spot with her multimeter. This approach allows for a decent range of parameters to be measured and analyzed. And if not as costly as sampling for lab analysis, it remains costly in time, constraining in planning and slow in reactivity.
In this blog, we explore the relative merits of each approach, and where remote environmental monitoring can fit in a compliance program.