An environmental group is asking the U.S. Environmental Protection Agency to step in to correct what it says is the state's failure to fix repeated violations at Tampa's wastewater system.

Tampa officials are vigorously contesting the group's findings, saying it took data out of context and misrepresented the city's wastewater spills. They also question the timing of the complaint, saying it might be aimed at sabotaging the city's drive to persuade Tampa Bay Water to allow the city to convert highly-treated wastewater to drinking water.

The state chapter of Public Employees for Environmental Responsibility, which made the complaint, is requesting that Mary Walker, the EPA's regional administrator, take over the city's permit and begin civil enforcement proceedings. The group says the Florida Department of Environmental Protection has failed to adequately police the city "egregious records of environmental noncompliance."

Braid Baird, the city's public works and utility services administrator said Monday he is "dumbfounded" by the complaint. The city will prepare a formal point-by point response, he said, within a week.

"We're a great success story, not a poster child for polluting the bay," Baird said. "I question the timing of this seeing as how hard we're working on TAP."

Jerrel Phillips, the president of the group's state chapter, said he doesn't know anything about the wastewater conversion project and denied the complaint was timed to stop it. The city's plans to convert wastewater into tapwater by pumping highly-treated wastewater into the aquifer is set to go before Tampa Bay Water on Feb. 18.

Phillips, a former state pollution enforcement attorney, prepared the group's complaint. It says the DEP "has dragged its heels and ultimately allowed violations of substantial gravity to go entirely unpenalized or, in some instances underpenalized."

Phillips says there have been 288 sewage overflows in Tampa since 2012 and 95 since the latest permit was issued in 2015. The Howard F. Curren sewage plant releases wastewater with too many nutrients into Tampa Bay, he says, and has been in non-compliance with its permit for half of the last three years and in serious non-compliance for two quarters during that period.

Phillips told the Tampa Bay Times last week that he hadn't calculated the number of gallons spilled in Tampa. Eric Weiss, Tampa's wastewater director, said the overwhelming majority of the spills are less than 1,000 gallons and are primarily caused by grease being flushed into sewers by cooking in private homes.

The non-compliance issues, he said, are caused by minor reporting errors or contamination of samples that are later explained to state environmental regulators. That's why the state hasn't taken action, Weiss said.

Baird and Weiss also noted that the complaint includes an assertion that Tampa was responsible for a 94,925 gallon spill in Stevenson Creek and Clearwater Harbor during Hurricane Irma in Sept. 2017.

"Obviously, our service area doesn't include Clearwater, " Baird said.

Phillips said he would doublecheck, but that was in the information contained in the reports he researched. He said Tampa's response was to be expected.

"The permit doesn't say as long as you have only 50 incidents, you're good to go. The permit says each one of these is a violation," Phillips said.

And the two instances of "significant non-compliance" for Tampa are telling, he said, noting that regulators would only assign such a classification if the system was in serious trouble.

Although the bay area's largest city has had reported sewage spills in the last few years, most of the state's attention has been fixed on St. Petersburg, which discharged up to one billion gallons of sewage into Tampa and Boca Ciega bays as well as city streets and waterways in 2015-16. The city continues to grapple with smaller spills as it seeks to comply with a 2017 DEP consent order to make $326 million in sewer repairs.

Phillips said Tampa's sewage woes aren't as serious as St. Petersburg's, but could reach that level if left unchecked.

"Could it ultimately develop into a situation like we had in St. Pete? Yeah, it could eventually develop into that type of situation," Phillips said last week.

The group didn't file a similar complaint against the Sunshine City, Phillips said, because "that situation was already being dealt with."

Tampa's situation, the group says, is an early "eco-test" for Gov. Ron DeSantis and is urging the new governor to begin enforcing environmental laws.

EPA officials didn't respond to a request for comment. DEP spokeswoman Shannon Herbon said the agency has taken enforcement actions against Tampa in the past, but is gathering evidence to more fully respond to the group's assertions.

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