An exploratory clean energy project in Ladakh starts by polluting
Geothermal fluid spilled during “exploratory drilling” dumped in Puga nullah
The magistrate of Nyoma subdivision in Ladakh ordered Oil and Natural Gas Corporation (ONGC) on August 23, 2022 to apply the highest precautionary standards at the Puga Valley Geothermal Power Plant, officials said.
Local naturalists have alleged that the plant poses several environmental risks and flouts green standards. A Union Territory (UT) Energy Development Department review meeting was held on August 20 based on the allegations.
The order which was based on decisions made at that meeting also warned the company of charges under Section 133 of the Criminal Procedure Code, 1973 (elimination of nuisances from the public space) in the event of a new offence. The department secretary also requested that a joint team be set up to visit the site and submit a field report.
A team from the Wildlife Conservation and Birds Club of Ladakh (WCBCL) visited the Puga geothermal project site on August 16, 2022 and found that the geothermal fluid spilled during “exploratory drilling” was being discharged directly into the Puga nullah.
Appalled at the sight of a dark, vaporous fluid mixing with crystal clear stream water, they had reported the matter to the Leh District Collector with photographic and video evidence.
They even raised the issue on social media. “CGSB is less concerned about environmental impact and there is no one from UT administration to oversee the project,” said WCBCL’s Tsewang Namgyal.
“The village of Sumdo is only 2.5 km downstream from where the fluid is discharged into the Nulla. Wild animals and cattle also drink the water from the nullah,” he added.
Puga, long recognized for its geothermal potential, is also a migratory stopover for migrating birds.
Tsewang Namgail, director of the Snow Leopard Conservancy India Trust and member of the Ladakh State Wildlife Board, said:
Puga is an important stopover for migratory birds of the Central Asian Flyway. Many birds, including the black-necked crane, feed along the grassy banks of the stream that runs through the Puga Valley.
“Therefore, the potential negative impacts of the ongoing geothermal research project and any subsequent larger efforts must be assessed to prevent damage to this fragile trans-Himalayan ecosystem,” he said.
ONGC Energy Center (OECT) had submitted a proposal to establish the Ladakh Geothermal Field Development Facility (1 MW) at Puga to the Ladakh State Council for Wildlife on October 4, 2021, seeking its approval. A however, a tripartite MoU had already been signed between Ladakh Autonomous Hill Development Council, UT administration and OECT on 7 February 2021.
Also, notwithstanding the concerns raised by some experts about the environment, the chairman of the board approved the project without any mention of the guarantees required. It was considered that the proposal was only for “a research project”.
Need better tracking
Geothermal fluid flowing in the Puga Nullah. Photo: Ladakh Wildlife and Bird Conservation Club
Tsering Tashi, founder of the charitable trust Ladakh Science Foundation, was of the opinion that the project should be monitored by a committee of experts from reputable scientific research institutions.
There are different types of geothermal power plants and the best practice to implement any of these processes is to return the geothermal fluid – after extracting the heat from it, back into the ground via a re-injection well.
The Puga geothermal fields are classified as “low-enthalpy” and “medium-enthalpy” geothermal reservoirs, and a feasibility study of the use of low enthalpy geothermal energy indicates that the binary cycle process may be the best for Puga.
Pouga has the potential to generate 1.5 MW using a binary plant, according to an assessment by the government’s electricity development company. The geothermal “binary power plant” uses a two-fluid heat exchange process in which the fluids exchange heat without coming into direct contact with each other. They are separated by a solid heat-conducting wall to prevent mixing.
The heat from the geothermal fluid (taken from an underground reservoir) is absorbed by the working fluid which has a lower boiling point. Once gasified, it is this gaseous working fluid that spins the turbines to generate electricity.
The system is also supposed to be in a “closed loop,” where geothermal fluid is injected back into the underground reservoir and the working fluid is condensed to a liquid state before heating up again.
“Geothermal energy is clean; it requires only one-fifth of the area compared to the areas required to harvest the equivalent energy from solar panels,” Dolma said. “The technology can operate with 90-95% efficiency, compared to solar power technology, which can only convert about 20% of incoming sunlight into usable energy.
“However,” she added, “even small-scale exploratory research projects can have environmental impacts that require assessment and mitigation built into the exploratory process.”
There are a few things that should have been in place before starting exploratory drilling: ‘Reinjection well’ reinject the geothermal discharge from the borehole into the underground reservoir and ‘blowing shutter’ to prevent tailings from flowing into the environment from the borehole.
These technical requirements, intended to mitigate risk, have cost implications. But ‘development’ policy approaches systematically externalize these costs, as in this case to the environment.
Puga nullah a important features of astrobiological significance. There is growing evidence that local hot springs can be associated with the origins of life. Studies in the boron-rich Puga geothermal system can provide important information about the origin of life framework.
Kunzes Dolma, geothermal energy technology expert and PhD student at Reykjavik University, Iceland, said:
This direct dumping of untested rejects from the borehole at Puga nulla could destroy crucial evidence for research into the origin of life. Discharge from the borehole must be stopped immediately.
An overall assessment of arsenic-rich geothermal fluids as environmentally hazardous materials recommends safe waste management. Geothermal arsenic typically comes from reservoirs several miles deep and can contaminate drinking water with possible cascading adverse effects.
When the depth of drilling at Puga is shrouded in secrecy and there is no statement from the administration as to whether the geothermal fluid has been tested for hazardous materials, precaution demands that the spill of geothermal fluid into the nulla be immediately stopped.
However, local environmentalists are skeptical as the joint assessment team has no geothermal experts and no date is mentioned for the field visit.
In such a situation, there must be urgent mitigation and bureaucratic procedures can only cause further delay, said WCBCL’s distressed Daya Dorjey. “CGSB is responsible for why there was no preparation required and why no precautions were taken before the drilling even started.”
Clean but not without risks
Fossil fuels have fueled human flourishing on the planet and triggered unprecedented climate change that now threatens them. There is a desperate need to seek clean renewable energy to support the human population approaching 8 billion.
Geothermal energy has this potential, although it has its drawbacks with the risks of minor seismic events, the dangers of arsenic-rich geothermal fluids and eventually most geothermal fields will cool down and become unproductive.
Usable geothermal energy is heat from the Earth’s mantle that is transferred to the Earth’s thin 40 km surface crust. Geothermal fluids – essentially water “trapped” deep in fractured rock that flows through “drilled geothermal wells”, are the medium from which the heat is harnessed.
Visible manifestations of geothermal energy include eruptions of lava, water and steam and they occur around geologic faults between tectonic plates. These sites have fractures in the earth’s crust and are potential locations where drilling for geothermal energy is undertaken.
The administrative area of the Union Territory of Ladakh straddles two tectonic plate sutures – the Indus Suture and the Shyok Suture.
The Geological Survey of India, as early as the 1970s, explored the geothermal potential of these areas. Today, UT which aspires to be “carbon neutral” is developing a geothermal energy project as a “clean energy” option. Thus, the path to this transition should also be clean.
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