Pollution levels have spiked in several major city drains that flow into the Yamuna despite the rains in August. According to reports of Delhi Pollution Control Committee (DPCC), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) have spiked in several drains. BOD indicates the power of the river to heat itself up. Higher BOD indicates more oxygen is required, while low BOD means less oxygen is being removed from the water, so it is cleaner. Chemical oxygen demand (COD) is the amount of dissolved oxygen that should be present in the water to oxidize chemical organic material. According to the report, the Najafgarh drain, one of the main polluters, recorded a BOD level of 54 mg/l, against the minimum standard of 30 mg/l.

Source: https://timesofindia.indiatimes.com/