BUDAPEST, Hungary (AP) -- Production restarted Friday at the metals plant whose broken reservoir unleashed a massive flood of caustic red sludge, even as villagers began returning to one of the affected towns in western Hungary despite warnings from environmentalists that it was too early and too dangerous to return.
Some 800 Kolontar residents were evacuated last Saturday after authorities said a wall of the factory reservoir could collapse further, releasing a second wave of red sludge after a calamitous break Oct. 4 created a deadly torrent.
Nine people died in the toxic flood and around 50 are still hospitalized, several in serious condition.
On Friday, about 30 people were driven to Kolontar in buses from a sports arena in the nearby town of Ajka, where they had been staying.
"Others are returning in their own vehicles from the homes of friends and relatives in the area," disaster agency spokeswoman Gyorgyi Tottos said.
The plant at the center of the catastrophe, the Ajkai Timfoldgyar metals plant belonging to MAL Rt., or the Hungarian Aluminum Production and Trade Co., restarted operations late Friday.
"As a result of preparatory tasks, the restart of the technological processes at the plant has begun," said Timea Petroczi, a spokeswoman for Gyorgy Bakondi, a former head of the national disaster agency who was appointed by the government to take temporary control of MAL Rt. "It will take a maximum of four days to reach normal operations. Full capacity will be reached next Tuesday."
Bakondi and an 18-member committee now have a decisive say in all aspects of the company and were talking with managers about how best to ramp up operations at the plant, which employs 1,100 people.
A protective wall of dolomite and earth - 610 yards (620 meters) long, with an average height of nearly 9 feet ( 2.7 meters) - has been built in Kolontar to shield the area from further spills of the red sludge, a highly caustic waste produced when making alumina, which is used to make aluminum.
"We just got back into our house and we're going to stay," Peter Veingartner, a 31-year-old body shop mechanic, told The Associated Press over the phone from Kolontar. "It seems that most people are coming back to Kolontar ... even those who lost their homes say they want to rebuild here."
Trucks carrying rubble were all over town and the home of Veingartner's aunt, Erzsebet, was among those being torn down, either because they were considered uninhabitable or stood in the way of the protective wall. Veingartner's house was on high ground and untouched by the flood.
"The streets are being constantly sprinkled and they're bulldozing the houses in the area that can't be salvaged, so there's still a lot of dust," he said.
Authorities refused to let journalists into Kolontar on Friday.
Greenpeace said it was too early to send residents back into Kolontar or restart the alumina plant because there was not enough data yet on the area's safety.
"The exact causes of last week's red sludge catastrophe still have not been clarified," Greenpeace Hungary said.
Greenpeace also warned about the high levels of airborne dust from the demolition work and the red sludge, which was starting to dry up.
"No reassuring information has come to light that would support the safety of staying in Kolontar in the long term," Greenpeace said. "No one has released exact data about the short- and long-term effects of the high content of fine dust in the air."
Tottos, the disaster agency spokeswoman, said it was mandatory to wear protective masks in the area, but the rule was not being strictly enforced.
Estimates of the amount of red sludge still in storage at the plant in Ajka range between 20 million and 30 million metric tons (22 million to 33 million short tons).
In theory, the red sludge is put into a holding pond, where water evaporates and turns it into a hardpack that can be used for construction projects. In practice, that is not happening in Hungary - when one enormous waste pond gets full, another one is built.
"There is no recycling of the dried up red mud in Hungary, although some unsuccessful attempts were made in the past," Gyorgy Banvolgyi, a senior engineer with nearly 40 years of experience in the aluminum industry, told the AP.
He said Hungary's alumina producers have taken the position that "the red mud may be used for other purposes down the road, but as there is no profitable use for it so far, so for lack of a better alternative, they are storing it."
Police - who on Wednesday had to release MAL Rt.'s managing director Zoltan Bakonyi after a judge ruled there was insufficient evidence against him - said Friday they had tried to question the plant's technical director, Jozsef Deak, but he refused to testify.
Deak, who was released by authorities on Thursday, is suspected of public endangerment and causing damage to the environment, charges similar to those faced by Bakonyi before the court decision.