urbanacres.in. Idol immersion water pollution checks are under way in Bhopal and Indore, with MPPCB testing lakes and ponds for contaminants. MPPCB is testing Bhopal and Indore water bodies for idol immersion pollution, including heavy metals, BOD, COD and dissolved oxygen. Bhopal (Madhya Pradesh): The National Green Tribunal (NGT) on Tuesday directed the authorities concerned to comply with Central Pollution Control Board (CPCB) guidelines on idol immersion to.