In a rare ruling on Wednesday, a multibillion-dollar geothermal project that proposes drilling geothermal wells thousands of meters deep in Yilan County was referred to the environmental impact assessment (EIA) grand assembly to decide whether a fourth meeting or a second-phase review is needed.
The referral was made by the EIA committee at its third meeting, with members reaching a consensus to either hold an extraordinary fourth meeting, or the project enters a second phase of environmental review, in which more stringent criteria apply.
Headed by anti-nuclear activist and National Taiwan University professor Kao Cheng-yan (高成炎), the project proposes drilling 10 geothermal wells in Lize (利澤) in Yilan County’s Wujie Township (五結) over a 10-year period. A private venture, the project is expected to cost NT$10 billion (US$304.2 million) and would generate up to 101 megawatts (MW) of electricity per year, making it the largest thermal power station in the nation.
With the wells burrowing deep past layers of rock and extending into the sea floor, the EIA committee expressed concern over active fault lines that lie at the proposed drilling site. It said the developer has not thoroughly surveyed the geological structure of the area or assessed the threat that earthquakes or other natural disasters could pose to the facility.
Fearing that such deep drilling might induce shallow earthquakes and cause pollution to the stratigraphic system and underground water, the committee referred the project to further review by the EIA grand assembly.
The committee also demanded that the developer conduct further seismic and geological studies and test drilling, map out an environmentally friendly withdrawal mechanism should the project be terminated and engage in comprehensive communication with residents.
Kao said that the technology that would be used to extract energy from geothermal resources involves inserting conduits into the rock layer and pumping cold water into the geothermal layer to absorb heat and generate steam power.
Engineer Wang Wei-ming (王偉民), who is in charge of project drilling, said that the conduit is made of a material that can withstand stress of up to 555 megapascals, which is more than 100 times more powerful than the pressure generated by the 921 Earthquake in 1999, so pipe fracture would not be a concern.
Given the technology used, should the conduit be fractured, there is only the risk of water leaking, but not of a steam explosion, Wang said.
Furthermore, should the faults dislocate, the wells would simply be abandoned and the project terminated without further geological and ecological impact, he said.
Groundwater pollution should not be a problem, since tap water and not groundwater would be used, with the plant estimated to use 250 tonnes of water every day, which is significantly less than other plants at Lize, Kao said.
Saying that test drilling and a geological survey should be funded by the government instead of being initiated by private developers, Kao threatened to withdraw the project and resubmit a larger one that proposes generating 250MW of electricity every year.
However, he agreed to the project entering a second phase of environmental review if the EIA grand assembly decides it is needed based on the current proposal.
Democratic Progressive Party Legislator Tien Chiu-ching (田秋堇) proposed holding an extra review by geological experts, given concern over the project’s geological impact.
Source URL: Taipei times