Waterkeeper study finds human-source bacterial contamination in Manuel's Branch; board urged to press city for focused testing and warnings

Colusa Waterkeeper volunteers told the City of Fort Myers Environmental Advisory Board that Manuel's Branch is showing persistent bacterial contamination consistent with human sewage and recommended immediate, targeted follow-up.

"We've confirmed over a number of tests that there's a human source to that contamination," said Jason Pim, a board member and advocacy committee chair with Colusa Waterkeeper, summarizing the group's source-tracing report and urging more frequent, higher-resolution testing. Ken, a longtime volunteer with the group, described how teams scanned outfalls and then ran human-source assays on promising sites.

The report, the presenters said, combined standard indicator analyses (enterococci and E. coli) with human-specific markers (HF183 DNA) and sucralose screening. Ken said the group found HF183-positive results at multiple outfalls and that every HF183-positive surface-water sample they retested also showed sucralose, an artificial sweetener used as a tracer for human wastewater. He said groundwater samples at embankments were positive as well, suggesting multiple human sources rather than a single, easily isolated break.

Why this matters: Manuel's Branch runs through downtown Fort Myers past Lee Memorial Hospital, adjacent athletic fields and Manuel's Branch Community…