The study analyzed the water quality of Pucang River in Sidoarjo Regency to control water pollution. They compared the water quality with Indonesian standards and found that it had worsened from moderately polluted to heavily polluted between 2018 and 2020. The researchers used pollution indices to determine the status of water quality and identified strategies to control pollution. The findings suggest that the river water is not suitable for its intended use due to the decline in water quality over the years.