Previous Coverage: Beach Warnings By The Numbers
TAMPA - For the second time this year, environmental investigators think they have located the source of bacterial contamination that regularly keeps swimmers out of the water at Ben T. Davis Beach.
Hillsborough County pollution investigator Byron Bartlett last week discovered smelly goo seeping up from the bottom of a ditch on the south side of Courtney Campbell Parkway. The substance was tested and found to contain genetic markers indicating it was human sewage.
The discovery prompted Tampa wastewater officials to speed up plans to replace 600 feet of sewer pipe near the trouble spot. Work should start in the next two weeks.
City wastewater Director Ralph Metcalf said his employees had tried to locate the leak using red dye but were unsuccessful.
'We don't know where it's leaking in this ditch; the dye's not coming up,' Metcalf said. 'At this point, it looks like the best thing is to bypass the whole thing and take that piece out of service.'
Bartlett found a sewage leak on the parkway in April. Tampa wastewater crews fixed the leak, but bacteria concentrations climbed again, causing the Hillsborough County Health Department to issue 11 swimming advisories at the beach this summer.
'We were still getting very, very high bacterial numbers with human genetic markers,' said Jody Harwood, a biology professor at the University of South Florida. Harwood leads a team studying bacterial problems at the parkway.
Bartlett continued investigating and narrowed the possible sources to Tampa's pressurized sewage main along the south side of the parkway, the Radisson hotel and Castaways restaurant.
Except for minor sewage leaks at the Radisson, Bartlett could find no evidence that the businesses were the source of the bacteria spikes. So he started taking samples along the route of the sewer main and determined the leak was west of the entrance to the Radisson.
'At one point, I stepped into a depression that didn't seem to be normal,' Bartlett said. 'That's when I discovered a place that was wet that shouldn't be wet.'
Samples that Bartlett took showed bacteria levels higher than 2 million colonies per 100 milliliters of water. The county considers unhealthy a fecal coliform bacteria level above 400 colonies per 100 milliliters. The cutoff for enterococci bacteria is 105 colonies.
More swimming advisories have been issued for Ben T. Davis than any beach in the Tampa Bay area. Water contaminated with high bacteria levels can cause gastrointestinal disorders, respiratory problems and skin rashes.
For many years, health officials thought the continuing problems at Ben T. Davis were caused by stormwater runoff carrying animal waste.
'The way it's constructed, stormwater is almost designed to flow right into that beach area,' Harwood said. 'Stormwater can carry really high bacterial counts without being indicative of sewage.'
Anthony Kasper, chief engineer for the Tampa Wastewater Department, said crews will start working in the next two weeks to reroute 600 feet of sewage pipe from west of the Radisson entrance to just east of Bay Harbor Drive.
Over the next several months, the department plans to replace 2,800 feet of sewage pipe beginning at a pumping station near the Ben T. Davis Beach pavilion continuing east to a manhole near the entrance to Landry's Steakhouse. Some sections of the pipe date to 1961.