<b>pH Control in Effluent Treatment Plant using PLC</b> In this paper, A few automated processes for a partial automation which can be mostly used in residential areas and industries. It is developed using PLC. It has explained the process of ETP in industries. The process include different parameters like flow, level, pH, DC motor, solenoid valves, pump are controlled by using PLC Allen Bradley Micrologix 820 and simulated by using software CCW Connected Component Workbench . As we know that effluents emitted by industries contains harmful chemicals which could lead to effect on environment and society. So by retreating these effluents could be a blessing in disguise. This process can’t be going through using manual process so here we need some automotive tools for that. That is why we make use of PLC programmable logic controller . PLC is recommended instead of other automation devices because of its versatility, robustness, reprogrammable nature and many other significant features. Allen Bradley PLC, solenoid valve, DC motor, float sensors, pH sensor. 896-899 Issue-1 Volume-2 Chaitra S S | K. P. Shobha | H. Prasanna Kumar