Nearly four weeks after Japan’s great earthquake, most of the 100,000 residents of this low-lying seaside town still have no plumbing. They relieve themselves in plastic bags — mixing in chemicals to harden the waste and hide the smell — and throw the bags into the garbage. Fortunately, trash collection, unlike sewage, water and gas services, has not been disrupted.

Located about 200 miles south of the earthquake’s epicenter, Urayasu should have been well beyond the danger zone. There was no tsunami wave. No buildings fell. Rather, what happened here March 11 seemed straight out of a science-fiction movie: As the ground shook, muddy sludge oozed up, gurgling out of newly formed cracks and swallowing what it could.

Today, the mud is dried and gone, but Urayasu, the home of Tokyo Disneyland, resembles a town reflected in a funhouse hall of mirrors: severely warped streets and fences, tilted houses and police booths, sunken utility poles and pushed-up manhole covers resting on three-foot-high piles of dirt. At Disneyland, the parking lot rippled and buckled, a ride the 68,000 patrons at the park that day hadn’t counted on.

To the list of destructive forces that have wracked Japan — earthquake, tsunami, radiation from a crippled nuclear power plant — can be added liquefaction, a phenomenon that occurs when the earth’s violent shaking forces sand particles, once packed tightly, to shift apart and allow water to seep in.

Moments after the quake, Urayasu literally began sinking into the ocean.

A man rides his bike through mud in Urayasu. (COURTESY URAYASU MAYOR'S OFFICE)

“It was like we were surfing,” said Chiharu Asami, 58, who operates a newspaper delivery service. “We could see the ground shaking and the telephone pillar sank two meters. The muddy water came right away, up to my ankles. Even when the water went away, the mud stayed for a week.”

‘Tomorrow comes’

At City Hall on Wednesday, Mayor Hideki Matsuzaki was working from an emergency command center on the ground floor, where a call center operates around the clock. City employees from the gas, electric, sewage and water departments were huddled around computers. A large town map, highlighted in various colors to mark different problem areas, dominated a conference table.

Behind Matsuzaki, a poster read: “Tomorrow comes.” He has been so busy dealing with the here and now, however, that he failed to collect ballots for the prefecture council elections, prompting a rebuke from Chiba Gov. Kensaku Morita.

“He hasn’t even visited here,” Matsuzaki scoffed. “We have to repair the lifelines before we have an election.”

He noted that Japan had dealt with significant liquefaction after the Kobe earthquake of 1995, but “nothing of this vast size.”

As much as 85 percent of the town — an area of almost 1,000 acres — had been submerged in mud, Matsuzaki said. He estimated it would take several years and cost $890 million to repair the infrastructure and reinforce it — an amount far exceeding the town’s $743 million annual operating budget.

Susumu Yasuda, a civil engineer from Tokyo Denki University, said that Urayasu is highly susceptible to liquefaction because the town, built after World War II, sits on reclaimed land made from a mix of volcanic ash, garbage and sand dredged from Tokyo Bay.

Although the Japanese government had enacted stricter liquefaction building codes for factories after a 1964 earthquake, most residential homes were built without 60-foot underground steel reinforcement poles, which were considered too expensive, Yasuda said.

He said he worries that Urayasu officials are rebuilding too quickly, noting that the ground remains vulnerable to repeated liquefaction if a major aftershock occurs. In Christchurch, New Zealand, a February aftershock from an earthquake in September sent mud oozing 20 inches above ground — higher than it had piled during the initial quake.

“If you rebuild without improving the ground, that’s not enough against an aftershock,” Yasuda said.

Repairing, rebuilding

The people of Urayasu have not complained too loudly about their misfortunes, which pale in comparison with the hardship along Japan’s northeastern coast. So far, one person has been killed in the town: a repair worker who was crushed by a steel beam Tuesday.

Still, hundreds have left their homes, taking rooms at the Disneyland hotels, which reduced their rates and allowed residents to use their hot springs baths. (Disney officials said they have repaired the parking lot, although the amusement park remains closed because of the nation’s energy shortage.)

Urayasu’s streets are filled with dump trucks, cement mixers and workers wielding hoes and pickaxes. There are also hundreds of sandbags filled by residents sweeping the mud out of their yards. One town official estimated the amount of sand collected at 195,000 cubic yards.

Ichizo Mase, 85, who lives with his daughter in a modest two-level house on a quiet street, said he tried to run outside when the earthquake struck, only to find his front door jammed. He escaped out the back and came around front to find the concrete steps pushed up several inches by mud.

But Mase considers himself lucky: His neighbors’ house had sunk by 20 inches, forcing all six family members to move out.

“People can’t live there,” Mase said. “Their floor is leaning at an angle. They said they feel unsafe.”

Special correspondent Kyoko Tanaka contributed to this report.