Hamilton's mayor has apologized for the leak that allowed an estimated 24 billion litres of sewage and runoff to flow into Chedoke Creek for years.

But, the mayor says, the city's decision not to tell the public the magnitude or duration of the leak was not a cover up, comparing those who believe the city was trying to hide the spill to conspiracy theorists.

"They believe that somehow we've colluded to try to do some harm here to the public at large," he said. "Nothing could be further from the truth."

Instead, the mayor insisted, the decision was based on "reasonably sound" legal advice from an outside environmental lawyer. The lawyer warned going public about the volume and length of the leak, which is being investigated by the Ministry of Environment, Conservation and Parks (MECP), could expose the city to major fines under provincial legislation.

"It was not based on some desire to not inform the public or some desire to hide things that would hurt them," said Eisenberger. "It was really designed to make sure we had all the information, that the investigations were complete and that we were able to not only protect the environment, but for future liability."

"It shouldn't have happened'

The city issued a press release last Thursday explaining a bypass gate in one of the city's combined sewer overflow (CSO) tanks had been left open without notification since Jan. 2014, allowing billions of litres of stormwater and untreated waste to leak into Chedoke Creek until it was discovered, and stopped, in July 2018.

"I apologize that the incident happened. It shouldn't have happened," said Eisenberger.

The city's release came out shortly before a story from the Hamilton Spectator based on confidential city reports that showed officials had known the volume and duration of the leak, but decided not to tell the public.

Eisenberger said the city always intended to release all information about the spill. They were just waiting for the investigation to be completed.

But residents weren't the only ones who weren't told. The Royal Botanical Gardens (RBG), which has dedicated years to restoring Cootes Paradise and acts as its steward, said its staff weren't told even though Chedoke Creek flows into the protected marshland.

Burlington Mayor Marianne Meed Ward said she also wasn't notified and that she believes the public had a right to know the extent of the discharge.

On Tuesday, she put out a press release including a list of questions about the leak she's still looking for answers to, including what the human health impact is and how they can be sure something like this never happens again.

The spill was discovered in July 2018 and stopped immediately, according to the city. (City of Hamilton)

Eisenberger said he's not aware of the all the details about why those parties weren't told, but said notifying "anyone and everyone is probably not conducive to a full investigation."

Still, he also apologized to the RBG, Meed Ward and other partners for "whatever upset it might have cause them."

"It's happened on our watch. It's not like we caused it, but the reality is the buck stops here and we're ultimately responsible," he added.

But, the mayor pointed out, it's not uncommon for the city to hold information back from the public, as it did in this case.

"We have many instances where we have information we cannot share because of liability issues, or because it's in the middle of an investigation," he explained. "This is not an isolated incident."

Mayor 'comfortable' with how he's handling situation

Despite "extensive investigations," the city says it hasn't been able to determine why the gate stayed open and why staff weren't alerted.

The MECP has issued multiple orders to the city in connection with the spill. The most recent calls for staff to come up with a final report on the impact of the sewage discharge and plans for remediation and submit it to the ministry by Feb. 14, 2020.

On Monday, the general issues committee voted in favour of a motion from Coun. Tom Jackson suggesting the city hire five people to physically inspect the city's sewage system and sample water.

24 billion litres of sewage and stormwater have spilled into Chedoke Creek in Hamilton over four and a half years. 0:44

Councillors Maureen Wilson and Nrinder Nann have made a motion calling for the city to apologize and make "any and all reports" related to the discharge since the incident was discovered last July public.

Both motions are scheduled to come before council Wednesday.

Tuesday marked the first time since the details of the discharge were shared that Eisenberger, who was in India on a trade trip when the story broke, has made any public comments on it.

When asked about his silence on the issue, he said he prefers to know all of the details of a situation before speaking about it.

"I'm very comfortable with the way I'm handling this and if it's not fast enough for some people that's unfortunate," he added.

As for anyone in the community who has lost trust in him, council or the city over the spill, Eisenberger said Hamiltonians, along with protecting the environment and the city's liability, are his top priorities.

"We have honourable people that are elected here that are doing this work in earnest and genuinely believe they're working in the best interest of the community at large."