Last week, 58 million gallons of partially-treated wastewater overflowed from the Northwest Plant.
But Mayor Rick Kriseman didn't tell city council members, the public or the media.
Warning signs were put up, per protocol, city officials said. But no other measure were taken to spread the word about the millions of gallons that flowed near Azalea Middle School.
It wasn't until the the city notified that state of that total this week that the massive overflow surfaced publicly.
That's because the wastewater was nearly clean, Mayor Rick Kriseman said Thursday.
Kriseman said the "reject water," which normally doesn't meet state and federal standards for being injected underground and is held in storage tanks until it can be processed again, posed no threat to the public when it overflowed into Jungle Lake and overflowed a storage pond, eventually crossing 22nd Avenue.
Most of it ended up in the stormwater system and, eventually, in Boca Ciega Bay.
So residents didn't need to know about it.
"They didn't need to be notified because it wasn't sewage, it was clean," Kriseman said.
He said he had tests of the "reject water" or sewage that has been processed almost to the level of being designated reclaimed water (that's able to be sprinkled on lawns). City tests of wastewater leaving the plant showed initial low levels of fecal coliform, but those levels never exceeded state law for reclaimed water.
The city had to call what overflowed "reject" instead of "reclaimed" because it had not undergone complete filtration, city officials said.
"I trust my scientists. I would notify residents if there was any public health risk. There was not," Kriseman said.
Plenty of Azalea residents and their council member Charlie Gerdes disagree.
Gerdes said he was shocked by the amount of sewage that overflowed at the Northwest plant. He also couldn't understand whyPublic Works Administrator Claude Tankersley never mentioned the spill when briefing council members a day after it ended on Sept. 7.
Why not tell residents what happened and include information that the wastewater isn't dangerous, Gerdes asked.
"I'm struck by the difference of perspective. We shouldn't be focused on the technicalities of do we have to notify the pubilic. We should be focused on transparency," Gerdes said.
Last August, an overflow of 15 million gallons of '"reject water" at the city's Southwest Plant sparked an outrage at Eckerd College and surrounding communities. Part of the anger was that the city didn't notify residents of that spill either until council member Steve Kornell raised the issue weeks later.
On the other end of the city Thursday, the sewage crisis deepened. The city revised its estimate of how much sewage had been dumped into Tampa Bay from 70 million gallons to between 78 and 93 million gallons.
Since Hurricane Hermine hit two weeks ago, the city has spilled or dumped around 151 million gallons, not including more than 40 manhole that overflowed all around the city. Those totals are still unknown as is the exact amount of sewage dumped into the bay. A broken flow meter prevented an exact tally.
Water Resources Director Steve Leavitt, responding earlier this week to a Tampa Bay Times public records request, said no work order or maintenance log exists for the broken meter because of the urgency of the situation.
Sewer officials have said no back up meters were able to measure the discharge into the bay.