Updated

CHRISTCHURCH, New Zealand -- Thousands of workers and volunteers cleared rubble Thursday in New Zealand's earthquake-stricken city of Christchurch, as mechanical diggers tore down wrecked buildings and workers poured millions of liters of spoiled liquids down a river.

Civil Defense director John Hamilton said public services were being restored in the region, as the city was spared Thursday from any more major aftershocks from Saturday's magnitude-7.1 earthquake.

Electric power has been turned on for all but 300 premises and drinking water supplies restored across the city -- but Hamilton warned it will take many weeks to restore sewerage systems and more than a year to repair buildings damaged in the quake and hundreds of aftershocks.

Millions of liters of spoiled milk and spilled alcohol from wrecked warehouses were poured into a flooded river and disposed of Thursday, after waste managers agreed the badly hit sewerage system could not cope with the liquids.

"We are sucking the milk and alcohol into trucks and disposing of it in the river," said Don Chittock, hazardous substance manager at Environment Canterbury.

"We're removing one million liters of alcohol from one warehouse alone," he told The Associated Press. "There's nothing more heartbreaking than walking into a warehouse and seeing all this red wine, beer and champagne on the floor."

With the Waimakariri River in high flow, "this controlled release means ... using the river to get rid of (non-toxic) material" out to the nearby Pacific Ocean, Chittock said.

Across the region, thousands of workers, including hundreds of university student volunteers, worked to clear mud from streets and gardens as inspectors checked building safety.

Mechanical diggers began tearing down unsafe buildings as hundreds of safety inspectors began checks on older commercial premises and thousands of suburban houses badly damaged by the temblors. Up to 100,000 of the city's 160,000 homes were damaged in the quake -- about 500 likely will be demolished.

Several Christian churches suffered serious damage, with several facing demolition.

At one site, Anglican Bishop of Christchurch Victoria Matthews stood beside an excavator in a construction hard hat and a raincoat to hurriedly deconsecrate a historic Anglican chapel, which had suffered irreparable damage.

Matthews was on a pastoral visit to rest home residents when a structural engineer declared the chapel a severe hazard.

As the excavator waited, engine running, the chapel's religious fittings -- including robes, chalices, altar rail and commemorative plaques -- were quickly removed.

The Bishop said she had almost no warning that the chapel faced demolition.

"So instead of wearing her Episcopal robes as she pronounced the final, formal, poignant prayer of deconsecration, she was wearing a yellow hard hat and a raincoat," the "anglicantaonga" website reported.

Saturday's powerful earthquake struck at 4:35 a.m. near the South Island city of 400,000 people, ripping open a new fault line in the Earth's surface, smashing buildings and homes, wrecking roads and disrupting the central city. No one was killed and only two people were seriously injured -- which authorities attributed to good building codes and the quake's early morning timing.

The city center remained cordoned off by troops Thursday, as a state of civil emergency remained in force. Only business owners and workers were allowed access.

Officials said Wednesday that the full bill for quake damage could reach 4 billion New Zealand dollars ($2.9 billion).