ST. PETERSBURG — Picture an Olympic-sized swimming pool. Now picture 106 of them.
The 70 million gallons of partially treated sewage the city of St. Petersburg now estimates it dumped into the waters of Tampa Bay after the drenching rains of Hurricane Hermine would fill all of them.
For 10 straight days, the city discharged waste from its overwhelmed sewage system into a pipe that emptied about a quarter of a mile off the downtown shoreline. That finally ended Friday.
Officials said a broken flow meter prevented them from coming up with a more exact tally. But wastewater officials came up with the 70 million gallon estimate late Monday. By law all such spills or dumps must be reported to the state.
St. Petersburg's estimate brings the official amount of sewage dumped into Tampa Bay's streets and waterways from the region's wastewater systems to 135.1 million gallons, a number that may continue to rise. That's roughly equivalent to 204 Olympic-sized swimming pools, which are generally 50 meters long and 25 meters wide.
Meanwhile, the Florida Department of Environmental Protection said it is preparing to issue a consent order to the city, which would require St. Petersburg to follow a plan to remedy the sewage spills or face fines.
The DEP was preparing to take action against the city before Hermine. An agency spokeswoman said public works administrator Claude Tankersley and water resources director Steve Leavitt were informed of the intent to issue a consent order at a June meeting. The state launched an investigation into the city's sewer system after it dumped 10 million gallons following Tropical Storm Colin in June.
Whether the massive sewage dump after the hurricane will broaden or stiffen the state's action was unclear Monday, DEP spokeswoman Shannon Herbon said.
The order is being negotiated and will be finalized within the next few weeks, she said.
Tankersley and Leavitt said they weren't aware that a consent order was being considered, said Mayor Rick Kriseman's spokesman, Ben Kirby.
Late Monday, Kriseman's office issued a statement: "As mayor and as an environmentalist, Mayor Kriseman hates that our city is having to deal with a black cloud — literally and figuratively — while so many great things are happening. But we have a plan and he is as optimistic and confident as he is outraged about this."
Earlier Monday, Leavitt confirmed that the dump into the bay wasn't the only outflow from a sewage plant. The city's Northwest plant had an overflow from Sept. 1 to Sept. 6 in its water tanks that hold mostly treated sewage, which flowed into nearby areas. An amount hasn't been estimated yet, Leavitt said.
Manholes also have overflowed throughout the city.
Since August 2015, St. Petersburg has dumped or spilled at least 111 million gallons of sewage. More than 81 million of those gallons have flowed into Tampa Bay, whose waters recently had been hailed an environmental rehab success story.
The City Council is expected to approve a budget later this month that includes $58 million to help add capacity and fix aging pipes its beleaguered system.
Leavitt characterized the state's attitude about the city's plan as "on board" and "supportive" in a Tampa Bay Times interview earlier Monday.
Herbon said the state considers the severity of the violation, if the permit holder is a chronic offender and the extent of environmental damage among other factors when considering whether to issue consent orders.
St. Petersburg operated under a consent order for its sewer system for much of the 1990s.
High bacteria levels have forced the city to close all three of its beaches again. Northshore and Spa beaches had been reopened, but closed again over the weekend. Lassing Park remained closed.
Last week, a University of South Florida researcher found preliminary signs of an antibiotic-resistant bacteria at Lassing Park and Harborage Marina.
Deputy Mayor Kanika Tomalin said the city hasn't contacted USF yet to learn more about the dangerous bacteria. Nevertheless, wastewater officials said the most recent spill was composed of less than 10 percent raw sewage, which is less than what city officials have estimated during previous discharges.
The revised estimates were derived from a consultant study earlier this year that showed about 12 million gallons a day of raw sewage flows through the system. During the storm, that figure probably didn't rise, but the city thinks about 150 million gallons in total surged through sewer lines in the aftermath of Hurricane Hermine, including sewage and stormwater.
Previous estimates made by the city that the discharge was up to one half raw sewage were incorrect, said Leavitt, who said he had been "shooting off the hip" when he made those statements following Colin.
Meanwhile city officials were keeping a wary eye on the horizon as another storm approaches.
Crews are draining emergency tanks at Albert Whitted wastewater treatment plant, whose closing last year removed nearly one-fifth of the city's sewage storage capacity.
If a storm approaches, the city will take other steps to free up as much capacity as possible.
But such measures will take about a week to complete. To complicate matters, sewage flows, while nearly back to normal at two of the city's three sewer plants, are still high at the largest, the Southwest treatment plant, Leavitt said.
And the approaching tropical wave won't wait a week. In a worst-case scenario, the storm could drop up to 6 inches of rain on the area by Wednesday afternoon, said 10Weather WTSP chief meteorologist Jim Van Fleet.
"If the rain falls too fast, that could be a problem for areas that have had sewage problems," Van Fleet said.
Times researcher Caryn Baird contributed to this report. Contact Charlie Frago at firstname.lastname@example.org or (727) 893-8459. Follow @CharlieFrago.