The continuous use of boilers in the manufacture spun pile concretes company causes increased exhaust gas emissions such as NOX gas from boiler combustion. In order to reduce NOX gas emission, clean water is used in the absorption process to tie the gases. The water resulting from the NOX gas binder will change color to become more concentrated which makes the water saturated in binding NOX gas. It is necessary to change the water in the tub shelter. Meanwhile the process of replacing cloudy water from tub shelter is still done manually. Therefore, in this research, a monitoring and control system for water turbidity is designed to improve the performance of the NOX gas binder. The monitoring system designed using a 16x2 LCD as a GUI will display the turbidity value on the NTU scale, while the control system designed uses Arduino Uno as a microcontroller and then uses a solenoid valve as an actuator to regulate the flow rate of water. Turbidity sensor type SEN-0189 is used as a water turbidity sensor and using a float switch to control the water level in the reservoir. The results show that the system is able to reduce the turbidity of the water from 250 NTU on the to 114 NTU.