IS OUR POTABLE WATER SAFE? Stephen Dias, Dona Paula
In the mid-70s and late-70s, I remember when I was working at Ciba Corlim plant in the Instrumentation section, before joining NIO in 1974, that in a pesticides manufacturing organo-phosphorous pesticides namely monocrotophos and phosphamidon, inspite of the effluents being strictly tested at their Quality Control laboratory for pH, biological oxygen demand (BOD) and chemical oxygen demand (COD), there was complete fish mortality in the testing stream before discharge into the Cumbarjua canal. This case of fish mortality happened despite the effluents having been treated I suppose with hydrochloric acid and lime and diluted to desired extent before discharge. However, necessary remedies were taken after clearing the testing stream within the pesticide plant and before discharge into the Cumbarjua canal. The irony is that the tested effluent had passed all the three tests for pH, BOD and COD but the organophosphorous content in the effluents had been above the permissible limits. It later came to light that one of the pesticides was an organophosphorous pesticide concentrate banned by the World Health Organization but was being manufactured at the plant in Corlim. Fish mortality has been observed in the recent times at our beaches in Goa, thus raising the alarm of organic or inorganic toxins in our rivers. Even the potable water that our pipelines supply after treatment of the water at the reservoirs have many a times high levels of sediment as well is turbid on occasions. In particular, it may be noted that mercury to the extent of 0.002 miligrams per litre is toxic and lead to the extent of above 40 micrograms per decilitre with the fact that bio-accumulation of lead occurs over time. Water in our wells near to industrial areas and industrial estates could contain organic and inorganic toxins that may render it unfit for drinking. In the face of such eventuality it should be ensured that the PWD as well as the Goa State Pollution Control Board should test the levels of toxins in the potable water that is piped for our use. Sent from my Samsung device
