About 320 industries manufacturing pesticides, chemicals, pharmaceutical products and steel have been established in the Patancheru Industrial Development Area in the Medak district, Andhra Pradesh, India. A Common Effluent Treatment Plant (CETP) was installed by about 110 industries that bring their effluents in tankers for treatment purpose. After treating these effluents, wastewater is discharged in a water stream called Peddavagu, which meets the main stream Nakkavagu flowing through Patancheru area. The river is also a paleo-channel, which means it transports its contaminated water to large distances invisibly undergound.
Open wells, dug wells and tanks have become useless and redundant. The ground water is no longer potable. Arsenic present in the Peddavagu migrates vertically and horizontally and contaminates the ground water in the wells of adjoining villages, which is indicated by the. The surface water TDS (Total Dissolved Solids) concentration was found ranging between 3000–5000 mg L-1. The toxins discharged include heavy metals like selenium, boron, chromium, nickel, lead, arsenic, and cadmium.
In October 2004, the Supreme Court Monitoring Committee on Hazardous Wastes verified the status of implementation of the Supreme Court orders. They observed that the two CETPs of Patancheru and Jeedimetla have to a certain extent reduced the quality of toxic effluents going into the open environment through drains and rivulets. But there has been a causal approach reflected in still-contaminated lakes and irrigation tanks, maintenance of current (high) pollution outfall norms and continuance of policies of promoting red category industries. A Division Bench of the High Court directed the A.P. Pollution Control Board (APPCB) to submit latest reports about the status of pollution in Patancheru industrial area this year.