Coca-Cola Co., the world’s biggest soft-drink maker, said its bottled-water plants in Japan are running 24 hours a day to meet demand amid fears of tap water contamination from a crippled nuclear power plant.

“The irradiated water scare affects every part of Japan,” Kei Sakaguchi, a Tokyo-based spokesman at unit Coca-Cola (Japan) Co., said today in a phone interview. “We’re making a full assessment of our product schedule and gave priority” to some products including water and tea, he said.

Companies including Coca-Cola, Fast Retailing Co. and Toyota Motor Corp. are trying to lessen disruptions of supply to survivors of the March 11 earthquake, the strongest on record to hit Japan, and the ensuing tsunami. The government last week asked beverage makers to increase production of bottled water after revelations of rising contamination in water and food triggered bulk buying.

Coca-Cola may import 1 million cases of mineral water from South Korea this weekend to meet demand in the Tohoku region, the worst affected by the tsunami, as well as Tokyo and its surrounding regions, Sakaguchi said. Suntory Holdings Ltd. and Kirin Holdings Co. also boosted orders for imported water.

Nestle SA, the maker of Pure Life and Perrier, donated 20,000 cases, or 500,000 bottles of water to Japan, according to an e-mailed statement. Danone, which manufactures Volvic and Evian, said in an e-mailed statement that shipments of water to Japan have increased since the earthquake.

Water Demand

“Demand for bottled water has led to shortages across various supermarkets and even Japan’s ubiquitous convenience stores,” research analysts Kentaro Taniguchi and Tomoko Takanoura wrote in a Euromonitor International report on March 22. “Sales of bottled water may benefit from the expected shortage of potable water.”

Coca-Cola, Japan’s second-biggest bottled-water maker by market share, has 28 plants operated by 12 bottlers in Japan and seven of them produce water, Sakaguchi said. Suntory had 30.9 percent of the nation’s bottled-water market last year, followed by Coca-Cola’s 15.9 percent and Kirin’s 10.4 percent, according to Euromonitor International. Coca-Cola sells its bottled water through brands including Dasani.

Levels of iodine-131 found in Tokyo’s tap water on March 22 and March 23 exceeded the recommended limit for infants, the Tokyo city government said last week. The levels have been below the limit since March 24, according to data posted on the government’s website.

Contamination

Elevated readings of contaminated sea water were found yesterday near Tokyo Electric Power Co.’s damaged Fukushima Dai- Ichi atomic power plant, Japan’s nuclear safety agency said today. Workers grappled with ways to reduce toxic radiation at the site of the world’s worst nuclear disaster in 25 years. The plant is 220 kilometers (135 miles) northeast of Tokyo.

The death toll from Japan’s worst postwar disaster climbed to 11,232, with 16,361 people missing, according to the National Police Agency in Tokyo. The earthquake and tsunami devastated the country’s northern coastline and forced several hundred thousand people to evacuate.