The study looked at the water quality of Semenyih River in an industrial area. Samples were taken from three stations over six weeks in 2017. The researchers measured six parameters to assess water quality, finding slight pollution from ammoniacal nitrogen. The results suggested that industrial activities were contributing to the water quality deterioration. The water quality index values ranged from Class III to IV, indicating that the river water could be used for irrigation with caution but would need treatment before domestic use.