River and water use documentation of the Chao Phraya river. The Chao Phraya River basin is the largest in Thailand, draining approximately 30% of the
country. Along its course this river passes through several cities, including Bangkok, and
ultimately flows into the Upper Gulf of Thailand. After passing through Bangkok, and before entering the Gulf, the Chao Phraya flows through Samut Prakan Province. A number of large canals connect to the Chao Phraya in this province, an area that houses a wide range of industrial facilities. A recent Greenpeace report reveals hazardous chemicals in the discharges from these factories, and high levels of toxic pollution in the canals. The study shows the presence of heavy metals, hormone disrupting chemicals, and human carcinogens in water and sediments.