Puga incident highlights need for monitoring

Ladakh is influenced by various geological activities that date back more than 65 million years when the Indian tectonic plate collided with the Asian plate and continues to slide under it. This has led to the creation of the Himalayan ranges and the high altitude Tibetan plateau. The platetectonic collision drained the Tethys sea and created the Indus, Shayok, and Yarlung Tsangpo drainage basins, which are the suture zones between the two tectonic plates. In Ladakh, this includes the Indus-Zangpo suture and the Shayok suture. Hot springs are the most visible manifestation of these sutures or faults. Such hot springs are found across Ladakh with a concentration in Nubra and along the Indus river. In addition, low-intensity earthquakes in the region are another indication of these active tectonic fault lines.
These primal energy resources have emerged as a glimmer of hope for an energy-hungry planet. Modern human civilisation has brought itself to the brink of a climate disaster through the over-exploitation of natural resources, which has fuelled the search for clean and renewable energy. Some of the most promising geothermal fields are located along fractures in the Earth’s crust. The hot spring sites in Ladakh have an unknown potential for geothermal energy resources.
Geothermal energy refers to the heat from the Earth’s mantle, which is transferred to its 40-km thick surface crust. Heat is harnessed from geothermal fluids—essentially water ‘trapped’ deep in fractured rocks that flow into ‘drilled geothermal wells’. In the 1970s, Geological Survey of India explored the geothermal potential of these sites in Ladakh. Presently, the Administration of UT of Ladakh is pursuing a carbon neutral framework for development, which includes the use of renewable energy. An MoU was signed between LAHDC, Leh, Administration of UT of Ladakh, and ONGC Energy Centre Trust (OECT) on 7 February 2021 to establish the Ladakh Geothermal (1 MW) Field Development Facility at Puga. This will be the first geothermal energy power plant in India.

Environmental and wildlife concerns
The Puga Geothermal Field is located inside the Changthang Cold Desert Wildlife Sanctuary. However, there is great demand for power in Ladakh and across the nation, and this pioneering project has been given clearance. In fact, the tripartite MoU was signed before OECT presented the proposal for approval to establish the Ladakh Geothermal (1 MW) Field Development Facility at Puga to the State Board for Wildlife Ladakh (SBWL) on 4 October 2021. Unfortunately, the SBWL approval does not mention required safeguards as the project has been declared as a ‘research project’. Project Manager of OECT, Uday Shankar explained that there is a clause that exempts such projects from wildlife clearances if the area required is less than 5 ha and has a energy generation capacity of 1 MW or less. Several wildlife researchers, including some members of SBWL, spoke on the condition of anonymity. They argued that the geothermal project should be seen in totality with envisaged scaling up, and not in isolation to ‘skirt’ the need for wildlife clearance.
The issue of safeguards is crucial as Puga valley is inhabited by human communities and is located on the Central Asian Flyway (CAF). It is also a nesting site for the black-necked crane (Grus nigricollis). The issue of safeguards and monitoring is very important as the project could cause fluctuations in the water table, impact the hydrology of marshlands, and cause disturbances through its operation and creation of infrastructure such as roads and powerlines. For instance, OECT is building vehicular paths through the marshes in Puga to facilitate the movement of their vehicles. In many places, this has blocked the stream and changed the hydrology of the ecosystem. This could have been addressed with simple eco-friendly designs that would not disrupt the ecological processes of this important wetland.

Blowout and its impacts
A team from Wildlife Conservation and Birds Club of Ladakh (WCBCL) visited the Puga geothermal project site on 16 August 2022 and observed that geothermal fluid from the borehole was being drained directly into Puga stream. They documented the discharge of the dark hot fluid in Puga stream and reported it to Deputy Commissioner, Leh, S. B. Suse who called his deputy, Sub District Magistrate, Nyoma, Jigmet Angchuk and asked for an investigation and immediate cessation of activity. As the media started reporting this incident, the administration called for a review meeting to understand the situation.
Director General of OECT, Ravi [he does not use a last name] addressed the media in Leh on 31 August. He explained that there was a blowout from the borehole at the drilling site. The drilling commenced in July and they discovered a shallow reservoir with high temperatures of 120-130 degrees Celcius at 39m and stopped drilling. He said, “After this, we started cooling the reservoir to continue drilling as the target depth is 1,000m.”
He further explained, “A ‘freak incident’ occurred during the process of cooling the shallow high temperature reservoir after power supply from the grid failed due to heavy rains and the generator set could not be started immediately. This resulted in a delay of 20 minutes before power was restored and the cooling of the reservoir stopped. This is when the blowout occurred. A blowout is an uncontrolled release of steam and hot water from a geothermal borehole.” This is the blowout that WCBCL members witnessed on 16 August and three days later when dark steaming fluid was still flowing out from the borehole.
Furthermore, an ash-like residue has collected in the area after the blowout and it has been left uncovered in the area. A source who inspected the site spoke on the condition of anonymity and said, “The wind is blowing this ash-like substance and polluting the larger landscape. This is very harmful for people and wildlife. It should be covered but no one has looked into this so far.”

Was the blowout discharge hazardous?
OECT has signed an MoU with Iceland Geosurvey (ISOR) for Geothermal Field Development in Ladakh. According to geothermal expert at ISOR, Dadi Thorbjornsson the discharge from the blowout was non-toxic and contained bentonite, cement, rock, and water. However, a paper published in Science of the Total Environment, which assessed the global occurrence of arsenic-rich geothermal fluids and identified them as environmentally hazardous. The paper highlights the importance of safe management of discharge. That said it also reported that geothermal arsenic generally originates in deep reservoirs located several kilometers below the surface. This implies that the discharge from the borehole, which emerged from a depth of 40m, was not hazardous. Project Manager from OECT, Uday Shankar explained that they had carried out tests and found that the concentration of arsenic in the borehole discharge is lower than in water from natural hot springs. ONGC and ISOR thus declared that the discharge in Puga was ‘benign’. However, these test results have not been made public so far.

The need for independent monitoring
ONGC claims that the blowout was a ‘freak incident’ and refuted any claims that it was an accident or caused by a mistake on their part. They claim that the drilling was based on scientific data. However, sources report that the drilling operation has not been carried out in accordance to standard procuedures for a geothermal well. OECT claims that the blowout could not have been prevented though experts claim it could have been aniticipated and its impact could have been contained.
ONGC and ISOR claimed that the geothermal well design is correct and their inability to control the blowout was due to a power failure that disrupted the cooling process. The blowout effectively ‘killed’ the well as OECT has now capped it. It is now planning to conduct exploratory drilling at another location in Puga. Geothermal experts at ISOR claim the earlier design was good and should be replicated with improved power backup systems.
However, the ‘unexpected’ discovery of a reservoir at 40m and the blowout cast doubts over the scientific diligence that should inform the drilling process. It also points to the need for independent scientific review of the project and its processes along with consultations with local stakeholders.
Geothermal energy is said to be cleaner than solar energy as solar cells emit more carbon dioxide in their lifetime than geothermal plants. Geothermal expert and doctoral researcher at Reykjavik University, Iceland, Kunzes Dolma said, “Geothermal requires 20% of the area solar plants require to generate equivalent energy units. Also, 90% of geothermal energy can be converted to usable energy.” She cautioned on the need for strict safeguards for the use of this technology and the risk of energy wastage due to improper implementation and felt that an independent committee of experts should constanly monitor the project.

By Narendra Patil

Narendra Patil is a freelance writer with years of experience in tiger and snow leopard conservation

(An earlier version of this article was published in Down To Earth on 29 August, 2022)

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