The thermal waters of this hot-spring village still gush from the volcanic rock in the folds of Japan's Northern Alps. It's a stinking soup of sulfur and minerals that turns milky white as it hits the outside air.

The fabled waters of Shirahone. Bone white. Just as advertised.

But there is something else in the water this summer. In July, a former employee of the village's largest public hot-spring bath, or onsen to the Japanese, told a national magazine that the managers were secretly adding industrial liquid to the baths to keep Shirahone's water white.

The offending onsen closed immediately, drained its baths and hung a sign on the locked front gate that said, "We Are Sorry." In the following days, three other onsens in Shirahone -- including one owned by the mayor -- either were caught or confessed to juicing their water to make it look whiter.

As with the older Japanese women who color their gray hair a fashionable purple, Shirahone's special look apparently comes from a bottle.

"Guilty, of course," Toru Tsuzuki, manager of one of the offending onsens, said when asked how he felt sneaking down to the baths during off hours to stir in the whitening agent. "We knew it was wrong. But the customers expect the water to be white."

It is this collision of expectations and reality that led to the trouble, the onsen owners say. The water was still coming out of the ground clean and loaded with minerals, they say. It just wasn't as white as it was 10 years ago -- nor as white as it looks in the town's brochures.

Customers began demanding to know where the white water had gone.

"People are used to the convenience of modern life, where you throw a switch to get what you want, and they don't understand what real nature is," said a somber Motoki Saito, the fourth-generation owner of the family-run Yukawa So inn. Saito describes himself as a purist who would never tamper with the water coming out of the ground, and he is not among the onsen owners accused of altering their baths.

"Nature is always changing, but Japanese people complain whenever a facility doesn't match their ideal image of an onsen," he said. "The Japanese don't know real nature."

The scandal has caused panic in a town that has been lauded in poetry but now attracts snickers at its mention. The mayor has resigned, and the other onsen owners are unsure how to regain the public's confidence.

The onsen scandal strikes a deep psychological blow to a nation accustomed to soaking in the cozy certainty that no one knows the business of bathing better than it does.

Japan is bath-crazy. Archaeological ruins point to the existence of a spa culture as far back as 6,000 years. And the most recent statistics show Japan's more than 27,000 onsens recorded 138 million overnight stays in 2002 -- in a country of 127 million people.

That number is supplemented by millions of day visits -- many by families. The boom has given rise to the development of massive leisure facilities near Japan's big cities, where amenities such as ping-pong tables, playgrounds and waterslides are offered alongside onsens the size of swimming pools.

The demand has created a decade-long drilling frenzy. Pipes are being sunk to greater depths, in many cases 1,000 to 1,500 yards into mostly volcanic rock.

Critics call the drilling overdevelopment and say it is causing some sources of water to run dry and pressure and temperatures to fall in others. In the case of Shirahone, operators say the lower water supply may be the reason the whiteness has begun to fade.

"The situation is out of control, and it is destroying the consumer's trust," said Tadanori Matsuda, a professor at Sapporo International University who has written a book critical of the onsen industry. Matsuda noted that onsen regulations, written in 1948, did not require that the water have a measurable mineral content as long as it was kept hotter than 77 degrees.

The result, he warned, is that some onsens heat up tap water and call it a special bath. Others have taken to recycling water, or allow the same water to sit and be used for a week or longer -- a shocking disclosure in a culture raised on the ritual of scrubbing thoroughly before entering what is supposed to be a clean communal tub.

Shirahone's problems are cosmetic compared with what critics say is the far graver threat of poor hygiene. In 2002, seven people died and 300 were infected by Legionella pneumonia contracted from bacteria in a new onsen, built with government money, on the southern island of Kyushu.

That year, Japan's National Institute of Infectious Diseases said it found amoebas that can host bacteria in 64 percent of 237 hot springs tested.

The Japanese Health Ministry now requires onsens that recycle their water to treat it with chlorine. But the government has rejected calls to toughen its regulations.

"Tightening the regulation means putting a burden on the industry," a government spokesman said. "The private sector should do whatever they can."

Yet the industry has balked at formal self-regulation. Attempts by the Japan Spa Association to introduce a Michelin-style star rating system were blocked by operators who did not want to reveal whether they were recycling water.

Matsuda says as many as 70 percent of onsens recycle, but disclosure remains voluntary.

"This onsen issue represents modern Japan," Matsuda said. "The victim is always the consumer. They are cheated and they die."

At least no one died in Shirahone. The village's onsen owners say they acted out of desperation, worried by the explosion in new spas and spooked by changes to the very thing that gave them an edge: the whiteness of the water.

White was gold in Shirahone. Spa pilgrims have been coming here since the 1880s to sink into the thermal waters and seek a cure for whatever ails them, hoping to benefit from the Japanese adage: "Three days at Shirahone and you won't catch a cold."

After collectively deciding to market the milky baths in 1969, the village saw the number of visitors quadruple to 400,000 last year. Clear water threatened that prosperity.

"The water here always changes color in the spring anyway -- it is more emerald in color from the snow runoff," Yoshio Kohinata, head of the town's onsen owners' union, said as he sat in the lounge of one of the biggest onsens in Shirahone.

Kohinata returned to the theme that the Japanese have an idealized view of nature and will settle for nothing less. The customers were complaining that the water wasn't what they expected, he explained.

"Obviously, it was a mistake and a bad thing to do," he said of the dye job, his tone turning mournful. "But the owners were tempted. They just wanted to give the customers what they wanted."