  Due to the global water crisis there is a strong need for real-time water
quality monitoring with high temporal and spatial resolution. This paper
presents an economical multiparameter water quality monitoring system for
continuous monitoring of fresh waters. It is based on a sensor node that
integrates turbidity, temperature, and conductivity sensors, a miniature
eighteen-channel spectrophotometer, and a sensor for the detection of
thermotolerant coliforms, which is a major novelty of the system. Due to the
influence of water impurities on the measurement of thermotolerant coliforms, a
heuristic method has been developed to mitigate this effect. Moreover, the
sensor is low power and with an integrated Long Range Wide Area Network module,
it comprises a system that is wireless sensor network ready and can send data
to a dedicated server. In addition, the system is submersible, capable of
long-term field operation, and significantly cheaper in comparison to existing
solutions. The purpose of the system is to give early warning of incidental
pollution situations, thus enabling authorities to take action regarding
further prevention of such occasions.
