TAMPA — More than a third of Tampa's sewage pumping stations lost power during Hurricane Irma, leading to an undetermined volume of untreated waste water being spilled throughout the city, and most of the pumping stations still lacked power Tuesday.
The city has 230 pumping stations. The hurricane knocked out power to 80 of them, according to Brad Baird, the city's top utilities official. As of late Tuesday afternoon, 75 still had not had electrical service restored.
As a result, sewage overflowed up through manhole covers and out of the stations themselves, according to a report from the city to the Florida Department of Environmental Protection. The city could not say Tuesday how much waste water had spilled, but officials said they would update the report once they knew.
Meanwhile, the city was using 20 portable generators to keep sewage moving through its system. Three of those are at three bigger stations. The other 17 are being shuttled between the other stations that are off-line. Though portable, the generators are much bigger than those available on the consumer market. The largest stand nearly 10 feet tall.
The waste water department has to rotate those generators while doing all of its usual maintenance to keep the collection lines clear and to rake screens to prevent clogs from forming.
"It's been very difficult on that department," Baird said.
With a few of the smaller pumping stations, the city can use a vacuum truck to pump out the holding tank, then put that sewage into the system at another point. And officials are processing paperwork on an emergency basis to hire a private contractor to install bypasses that would reduce the demand on some stations and help keep sewage moving.
Power from Tampa Electric also went out to the David L. Tippin Water Treatment Facility and the Howard F. Curren Advanced Wastewater Treatment Plant. In both cases, backup generators kicked on, but some partly treated sewage spilled out of the waste water plant for several minutes as the facility made the transition from its regular power source to the backup.
"That will end up being our largest overflow," Baird said. At that point, the plant, which is permitted to handle 96 million gallons of sewage a day and can handle 200 million gallons a day, had waste water flowing in at a rate of 170 million gallons a day.
Also, the sewage treatment plant lost the fiber optic service from Spectrum that allowed it to run a central supervisory control and data collection control board. Without that, Baird said, the city was "flying blind" for several hours during the storm because it had no data on what was going on throughout its collection network.
"That was difficult because you felt helpless," he said. "You had to make some educated guesses."
As a result, waste water staff stationed at the larger stations had to watch the flows from smaller stations upstream, and, if they changed, try to deduce whether there was a problem. Once the storm's winds dropped below 40 mph, the city began sending crews check on the smaller stations.
Service to the control and data system was restored early Monday morning.
Losing the power is something that has Mayor Bob Buckhorn thinking about buying more generators and fuel so it can be more self-reliant in future storms.
"I don't like being at the mercy of somebody else," he said.
Issue in Clearwater, St. Petersburg, too
Irma brought more wind than rain through Tampa Bay over the weekend, but St. Petersburg and Clearwater didn't escape some sewage discharges.
Clearwater had a power-related 1.6 million gallon spill during the storm. A freak equipment malfunction led to the sewage spill into Stevenson Creek in Clearwater early Monday.
A power outage caused a part to fail, which caused pumps to fail at the city's Marshall Street sewage plant at 1605 Harbor Drive about 12:50 a.m., said David Porter, the city's public utilities director. The partially treated sewage flowed into Stevenson Creek. It had gone through two stages of wastewater treatment but had not been filtered or treated with chlorine, which kills bacteria.
St. Petersburg officials said their spill was contained on the property of the Northeast sewage plant. The city spilled 430,000 gallons of partially-treated sewage on Monday afternoon after the storm moved north. A faulty sensor in a holding tank at the Northeast plant at 1160 62nd Ave NE became stuck, falsely showing partially-treated sewage at levels below what was really in the tank.
The partially-treated sewage eventually spilled over the top of the tank until workers noticed at 4:35 p.m. but was contained to the plant property.
Contact Richard Danielson at email@example.com or (813) 226-3403. Follow @Danielson_Times