An unusual geographical phenomenon in Olpad, a small town close to Surat city, is causing concern among the people and the district administration.

Underground water has started welling up since Saturday through whatever opening is found, in one case through a well about eight feet above the level of a nearby pond. Most of the potable outlets have also turned saline, reports received here said. The people in the area have been advised against consuming the water there, an official spokesman of the Gujarat government said.

The district authorities are consulting experts to find the reason for the phenomenon. The local people fear that it could be the result of some drastic geological activity under the surface of the earth and cause serious natural disaster.

The reason for the fear is that the area is rich in oil and gas reserves with explorations being carried out by both the Oil and Natural Gas Corporation (ONGC) and a multi-national company, NICO.

Olpad Sub-Divisional Magistrate H.K. Vyas said the cause is being investigated by experts from the ONGC. Surat Collector A.J. Shah said the district authorities were in touch with officials of both the ONGC and NICO and there was “no cause for worry as things are under control and our officers are monitoring the situation.”

A spokesman of the ONGC, however, ruled out gas and oil explorations as the cause of the unusual event. The spokesman claimed that the initial examinations of the water did not show the presence of any hydro-carbon.

The ONGC has four wells and NICO about 12, most of them of gas, in the region and so far there was no report of any leakage of oil or gas from any of the wells, the spokesman said.

Environmental activists in the region, however, feel that the reason could be exploration of oil and gas at a very shallow level. An activist, M.H. Sheikh said normally explorations were carried out at a depth of 750 metres and beyond, but in Olpad region, the hydrocarbons had been found and being explored at the level of 200 to 250 metres.