This chapter contains information related to the oxidation-reduction potential (ORP) in aqueous solutions, aiming to extend some aspects from theoretical electrochemistry to practical environmental monitoring and engineering applications. A more comprehensive and precise continuous monitoring of water quality for groundwater, surface water, wastewater, and drinking water could be achieved by deducing relations between ORP, the concentration of the oxidants and reductants in waters, pH, and temperature, delivering valuable information for the better comprehension of the requirements necessary to design an automated water quality monitoring system with real-time transmitted data, assuring better water governance. Such a system is presented as a case study related to an early warning of preliminary ecotoxicity. The case study was conducted by installing water pollution monitoring equipment on a passenger ship sailing on the Sulina Channel in the Danube Delta, Romania.