‘Freak incident’: ONGC, ISOR downplay geothermal fluid discharge into Ladakh’s Puga nullah

Both agencies also said the water discharged from the borehole after a blowout August 16 was benign

By Narendra Patil
Published: Friday 02 September 2022
Geothermal fluid flowing into the Puga nullah. Photo: Wildlife Conservation and Birds Club of Ladakh

The Oil and Natural Gas Corporation Energy Centre (OECT) and the Iceland Geosurvey (ISOR), that have signed a memorandum of understanding (MoU) for developing a geothermal plant in Puga, Ladakh, have termed a recent accident at the site as a ‘freak incident’.

They have also said the geothermal fluid that leaked from the ground and flowed into the Puga nullah, a tributary of the Indus, was benign.

Read Exploratory clean energy project in Ladakh begins by polluting

Ravi, the director-general of OECT, told media in Leh August 31, 2022 that the team at the site had encountered a shallow reservoir at a high temperature of 120-130 degrees Celsius while drilling between August 4 and 9.

The team immediately stopped the drilling at a depth of 39 metres depth. Further drilling required cooling the shallow reservoir. Due to heavy rain on August 16, the power supply from the grid needed for cooling failed. There was a delay of 20 minutes in restoring the power supply and this is when a blowout occurred.

A ‘blowout’ is an uncontrolled release of steam and hot water from the geothermal borehole. The blowout threw up muck from the geothermal drill hole.

An expert at ISOR told this writer that the discharge from the blowout contained non-toxic bentonite, cement, rock, and water. Geothermal arsenic typically originates in deep reservoirs of several kilometres and probably the discharge from the borehole that is only 40 metres deep was not hazardous, the expert added.

Meanwhile, a test has revealed that the water of the Puga nullah had more arsenic content than the geothermal fluid discharged August 16.

The ONGC has now closed the borehole and is all set to conduct further exploratory drilling at a different location on the same 5 hectares of land in the Puga hot spring area that has been granted wildlife clearance by the state board for wildlife.  

The magistrate of Nyoma subdivision in Ladakh had ordered the ONGC August 23, to practise the highest standards of precaution at the geothermal energy plant.

Local naturalists had alleged that the plant posed several environmental risks and was flouting green norms.

Puga is an important staging site for migratory birds in the Central Asian Flyway. Many birds, including the black-necked crane, feed along the grassy banks of the stream flowing through the Puga valley.

OECT had presented a proposal to establish the Ladakh Geothermal (1 MW) Field Development Facility at Puga to the Ladakh State Board for Wildlife on October 4, 2021, seeking its approval.

A tripartite MoU, however, had already been signed between Ladakh Autonomous Hill Development Council, UT administration and OECT on February 7, 2021.

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