ST. PETERSBURG — A top wastewater official once again blew the whistle Tuesday, saying that the 58 million gallons of waste that spilled from the Northwest treatment plant was not as clean as the mayor has asserted. In fact, it's a potential public safety hazard.

The city posted warning signs in the Azalea neighborhood near the Northwest plant, but did not release any details about the spill until Sept. 12 — five days after it was over.

"They didn't need to be notified because it wasn't sewage; it was clean,'' St. Petersburg Mayor Rick Kriseman said Sept. 15.

But Craven Askew, a chief plant operator at the city's Northeast wastewater treatment facility who has sought federal whistle-blower protection, sent an email and documents to city officials on Tuesday saying that St. Petersburg's own records revealed the risks contained in that 58-million gallon release.

"I noticed the following 10 violations throughout the spill," Askew wrote. "Public safety and the environment is suspected to be possibly in danger due to the sewer (sic) spills produced by the Albert Whitted … and Northwest (plant) spills."

Late Tuesday, U.S. Rep. David Jolly said he had met with Askew and would call for a full-fledged investigation by the U.S. Environmental Protection Agency. He and Askew would work together.

"It might go higher than that," Jolly said.

Albert Whitted is the plant through which the city released up to 93 million gallons of waste into Tampa Bay after Hurricane Hermine. All told, the hurricane caused St. Petersburg to dump up to 151 million gallons of waste into streets and waterways from its aging sewer system.

One of the documents Askew provided showed that the city told the Florida Department of Environmental Protection that it released treated effluent from the Northwest plant. But Askew said high turbidity — or cloudiness — levels and periods of low chlorine, which kills harmful bacteria, contradict the city's statement.

Askew contradicts Kriseman's earlier assertions that the massive spill was essentially reclaimed water — the kind of water that many residents sprinkle on their lawns.

Askew's email pointed to high turbidity levels for about 30 hours between Aug. 31 and Sept. 4, which he says indicate the sewage Kriseman said was "clean" was considerably dirtier.

Kriseman defended his earlier statements. He said low fecal coliform bacteria counts are the crucial measure of how clean wastewater is. Until he sees proof otherwise, the mayor said, he's sticking by his previous position.

"The information that I had making those statement then and now is based upon testing results and bacteria levels," Kriseman said. "If it wasn't safe, I'd be the first one screaming about it."

Public Works Administrator Claude Tankersley said turbidity is just one of many parameters used to determine wastewater quality. Cloudy wastewater, he said, could be caused by tree bark or paper. Normal rivers or streams have high turbidity, he said. Murky substances could include coffee, milk or tea, Tankersley said, which are not dangerous.

Tankersley agreed with the mayor that the levels of fecal coliform levels are much more important.

The Tampa Bay Times asked an independent consultant to review the sewage records released by Askew and compare them to the mayor's statements. Thomas Butler, chairman of the Suncoast Utility Contractors Association of Tampa, said they show the 58 million gallon release from the Northwest plant did not meet state standards for reclaimed water.

"Simply put, there were values that did not meet minimum standards as per FDEP (Florida Department of Environmental Protection) permit guidelines for reclaimed water," Butler said. "So for the mayor to say that it was nearly the same as reclaimed doesn't seem quite right."

Butler noted that the records provided by Askew show high turbidity and low levels of chlorine — which is used to disinfect waste. Those levels fall short of state standards for reclaimed water or treated effluent, Askew contends.

Kriseman did not back down from his statement last week that the Northwest release "wasn't sewage, it was clean." The mayor said Tuesday that the wastewater essentially met reclaimed water standards. City officials said they reported it as "reject" water — a slightly dirtier classification — only because it didn't go through the final stage of filtration before it had to be released.

That spill, which began Sept. 1, entered the Azalea neighborhood near the Northwest plant and even crossed 22nd Avenue N. The city reported it verbally to the DEP — but not the public, even after it ended on Sept. 7.

Tankersley, who briefed the City Council on the sewage mess the next day, didn't mention the Northwest spill. Signs were posted on 22nd Avenue N, where the sewage coursed across the street and into residents' yards. The city told the state, but no other local notification was given.

Residents didn't need to know, the mayor said last week, because there was no public health risk. But Askew said the wastewater records he released show there were risks.

Tankersley countered that Askew is only one of 30 licensed plant operators in the city. Tankersley said he would gather opinions from all of them and present his findings as soon as possible.

"Their voices have not been heard on this," Tankersley said. "I think that's important."

Tankersley, the city's top public works official, declined to comment on most of Askew's claims, saying he hadn't had a chance to fully review the records.

"That's Mr. Askew's opinion, I respect it," Tankersley said. "But I'm not a licensed operator."

Askew, one of the city's three chief plant operators, could not be reached for comment.

Last week, Askew sought federal whistle-blower protection status after emailing documents, including a 2014 study that showed city officials should have known that closing the Albert Whitted sewer plant on the waterfront could lead to sewage problems.

Since the plant closed in 2015, St. Petersburg has dumped or spilled about 193 million gallons of raw or partially-treated sewage into waterways.

City Council chairwoman Amy Foster said the latest revelations again illustrate the need for St. Petersburg to quickly release information whenever there's a sewage spill.

"Instead of focusing on semantics," she said, "we need to focus on solutions."

Contact Charlie Frago at cfrago@tampabay.com or (727)893-8459. Follow@CharlieFrago.