WATER POLITICS

Taiwan Semiconductor Manufacturing Co. is participating in a program in Japan to preserve groundwater resources by flooding unused paddy fields, amid concerns that its chip factories in Kumamoto prefecture could cause water shortages in the area.

Twenty years ago, Teruyuki Otaguro, a lifelong Kumamoto resident, saw something “surreal” at Lake Ezu, a popular spot for locals to fish and boat. As he walked around the lake, he saw hundreds of carp trying to squeeze through a narrow waterway, some swimming on top of each other, as they tried to get out of the lake. It was hot, and rain hadn’t fallen in days.

“The image stuck with me for a long time,” Otaguro told Nikkei Asia.

The main source of the lake, water gushing from underground, had been significantly declining since the 1970s. The fish appeared to be attempting to escape the evaporating lake into connecting rivers.

Today, Otaguro is secretary-general of the Seta paddy field infiltration council, a local organization in Kumamoto founded last year that works to preserve groundwater in the area. His organization arranges for around a dozen rice farmers to collect water in their unused paddy fields for a few months in the winter to let it seep back into the ground. Other similar organizations in Kumamoto are funded in part by TSMC and other companies operating in the region, including Sony.

The world’s biggest contract chip maker is building two factories in the southern island prefecture as it tries to diversify its manufacturing footprint, which has long been concentrated in Taiwan. Its arrival in Kumamoto ignited a rush of investment by both Japanese and Taiwanese suppliers of TSMC.

Semiconductor manufacturing requires many things, from experienced engineers to multimillion-dollar lithography machines. But what is not often discussed is the large amount of water it needs. Advanced chip factories use a few thousand tonnes of water a day, mainly to wash silicon wafers as part of the production process.

This is a problem for Kumamoto and its surrounding region of approximately 1,000 square kilometers. The population of around 1 million relies heavily on groundwater. This is due to the land being covered in volcanic ash from Mt. Aso in the east, which has a “permeability comparable to sand in its natural state,” said Tsutomu Ichikawa, an emeritus professor at Tokai University.

Rain and water used for farming is absorbed by paddy fields at a rate five to 10 times higher than in other parts of Japan, and this water gradually runs toward the sea, moving slowly, at an average pace of around 1 kilometer a year. It takes 20 years or so for rainfall near Mt. Aso to reach the city of Kumamoto. “It is the largest region in Japan, and one of the rarest in the world, where such a large population drinks the same groundwater,” Ichikawa said.

Kumamoto residents are able to drink mineral-rich water straight from their taps. The area has also become a base for brewers to make shochu, sake and other alcoholic beverages. Suntory has operated a brewery there since 2003.

“Natural water is essential in beer brewing,” Suntory told Nikkei Asia. “We carefully selected a location where high-quality, natural water could be sourced and built our factory in this area.”

But groundwater resources began declining dramatically in the 1970s as more farmland was paved over and the number of rice farms fell. Efforts from the early 2000s by local governments to encourage farmers to recharge groundwater supplies have helped levels recover somewhat, and Kumamoto prefecture has revised its guidelines to require big water users to return as much water as they use.

TSMC’s recent arrival, however, has sparked new concerns.

The Taiwanese chipmaker estimates that its two plants will consume around 8 million tonnes of groundwater, starting in 2028, an amount equal to around 5% of the current annual ground water supply in the Kumamoto region.

“Besides the amount of groundwater being pumped out of the ground for use, the reduction in [potential] water infiltration volume is also likely to become a significant issue,” Tokai University’s Ichikawa said. New roads and infrastructure, fueled by the chip investments, will cover up more land. In addition, the aging and shrinking population has led to more farmers giving up on the industry altogether, he said.

TSMC has been proactive about replenishing the water supply. According to the Kumamoto Groundwater Foundation, an infiltration organization covering 11 municipalities, the company has committed to returning around 2 million tonnes of water underground.

JASM, the operator of TSMC’s Kumamoto plant, recently announced a partnership with municipalities and an agricultural collective to buy local rice at above-market prices to serve in the factory’s cafeteria. The partnership is aimed at promoting rice farming in the area, which, in turn, should lead to more water infiltration.

In announcing the program on Aug. 6, JASM President Yuichi Horita said the company is “dedicated to preserving this precious resource. … We continually strive to reduce water consumption and improve recycling rates through industry-leading water resource management.”

JASM previously announced that it plans to recycle 75% of the water it uses at the plant.

Farmer-led groundwater recharging efforts, however, face many challenges. For example, farmers are only paid around 4 yen (3 cents) per tonne of infiltration, much less than they can make from growing carrots, for example. And many of the farmers in Otaguro’s organization are in their 70s and may retire soon.

Kimio Katsuya, secretary-general of the Kumamoto Groundwater Foundation, said another challenge is getting Taiwanese suppliers to participate in these efforts.

“We are forecasting that by the end of this year, when [TSMC’s plant] will start operating, partner companies will also start to become more active in Kumamoto,” he said. The foundation has not been approached by Taiwanese suppliers yet, he added.

Most farmers, however, are taking part in the laborious work recharging groundwater supplies to protect the water resources that are vital to their lives.

“JASM didn’t come to us to request anything,” Otaguro said. “We’re just trying to do a service for the future of Kumamoto.”