Industrial effluents with high levels of toxic heavy metals can impact wastewater treatment plants. A study in Vaal, South Africa, monitored wastewater from industries, a treatment plant, and the Vaal River. Results showed higher levels of heavy metals in industrial samples, with some exceeding safe limits in treated wastewater. The treatment plant was effective in maintaining most parameters within standards, but concerns remain about heavy metal levels in the final effluent. Continuous monitoring and maintenance of the plant are recommended to protect the health of the Vaal River and its biodiversity.