COMBA WELL CONTAMINATION: OIL, GREAS BELOW DETECTABLE LEVEL

MARGAO: In an interesting development vis-à-vis Comba well contamination, re-examination of well water samples by the Goa State Pollution Control Board has revealed that oil and grease was below detectable level.

The latest report from the Pollution Control board -- which had earlier submitted that the well waters have been affected by oil and grease -- comes against the backdrop of a report submitted by BITS Pilani stating that the scum seen on top of the well waters in Comba area was not due to any petroleum products, but was due to iron bacteria and iron content in water.

GSPCB Assistant Environment Engineer, Sanjeev Joglekar in his report submitted to the inquiry officer, deputy Collector Johnson Fernandes stated that the reports indicate that the value of pH is below the prescribed limits for drinking water. Joglekar, however, said that this time round, it was observed that the oil and grease is below detectable level in all the wells which the samples have been collected.

When contacted, deputy Collector Johnson said the latest reports submitted by GSPCB indicates that there is no presence of oil and grease in the water wells. “I will submit a detailed report on the sample testing by both GSPCB and BITS Pilani to the district Collector, G P Naik for further action”, he added.

BITS Pilani’s Assitant Professor, Biological sciences, Dr Srikanth Mutnuri had earlier concluded there was no presence of oil and grease in the wells and had recommended treatment of the affected wells by aeration and shock chlorination as the initial step, adding that the affected wells can be analysed again after above initial treatment to decide upon the requirements of further treatment.  “The district Collector will take a decision on the question of treatment of the wells through aeration”, Johnson said.

In fact, Dr Mutnuri had stated that the problem is not very serious as initially thought and can be resolved easily, adding that the oil like layer was found in well not in use in recent times, while no oily layer was noticed in wells which are in use.

His report spoke about the presence of iron bacteria which was observed as slime on the ouster walls of the container with which water from contaminated wells were drawn”, he said, adding that iron bacteria are red orange in colour and caused smell that resembles fuel oil or sewage or that of some decaying matter and are greasy to touch. These bacteria are common in wells which have been idle for a while, the report added.