Goa will ask Central Pollution Control Board (CPCB) to delist five of the states river stretches from the polluted list, after these stretches were found to be now complying with the Boards prescribed standard.
CPCB had earlier classified all of Goas 11 major rivers as polluted. Taking note of this, the(NGT) had asked the Goa government to formulate a river rejuvenation plan.
The Goa government had accordingly formed a river rejuvenation committee, who drew the required plan and its implementation is in progress.
The river rejuvenation committee, therefore, proposed that CPCB should be requested to delist the rivers of Chapora, Assonora, Valvonti, Khandepar and Talpona from the polluted river list.
The State Government had submitted a Rs 15 crore performance guarantee to the NGT over implementation of the action plan.
The rejuvenation plans objective is to restore the water in the polluted rivers to bathing standards.
Based on data collected by CPCB, the Goan rivers were declared to be polluted due to low biochemical Oxygen demand (BOD). BOD measures the amount of oxygen needed to decompose organic material in a unit volume of water.
Since BOD levels vary widely in river stretches, the BOD is prioritised across five categories based on BOD concentration.
The highest priority refers to all locations which exceed BOD concentration of 30 mg/l (30 milligrams per litre) and this level is now considered similar to discharge of sewerage.