Now that Montreal’s 36-hour boil water advisory is over, recriminations, accusations and investigations are now all on tap..

One opposition party leader said that Mayor Applebaum – who had taken some time off to mourn his brother – should have been more present. “Politically there was something wrong. the mayor was not there, someone else had to be there,” said Projet Montreal leader Richard Bergeron.

For 36 hours 1.3 million people in Montreal and several surrounding municipalities were deprived of clean drinking water after an error at the Atwater filtration plant.

Renovations at the largest water cleaning plant in the province required the water level in a reservoir to drop, but the water levels got so low that sediment was stirred up.

Louise Bradette said the city's Civil Security agency has begun a post-mortem investigation that is expected to last days, however she could not offer specifics about what would be examined, aside from saying that everything will be looked at from start to finish.

She did, however, respond to complaints that the city was insufficiently pro-active when it came to informing citizens of the unprecedented aquatic adventure. 

Some suggested that the city should have a system to automatically phone residents to warn them, but that too is difficult on such a scale, as only 10,000 calls can go out per hour.

One can sign up for that list, however. "There's a way you can register online with your cell phone number to be sure that if something happens again with drinkable water or something else we could reach you really fast on your cellphone with an alert message," said Bradette.

Mayor Michael Applebaum said Thursday night, in the news conference where the boil-water advisory was dropped, that it was not a problem with equipment.

"It was not a mechanical error. Now we've got to make sure how the process was done and how it was followed and were all of the measures followed in order to do a procedure of this nature," said Applebaum.

One local water experted said he's waiting anxiously for the results of the investigation.

“I personally doubt that it was an error as such. It was just something that wasn't anticipated at all. Maybe this was a blessing in disguise in a way that everyone can learn from this,” said Professor Ronald Gehr of McGill’s Civil Engineering program. “I can't imagine any treatment plant would have anticipated that this would happen.”

“The contamination came from a totally unexpected source which was at the very end of the treatment process and therefore completely safe. However since this had never been anticipated - I can't imagine any treatment plant would have anticipated that this would happen - there was no measurement device to trigger a concern,” he said.