Calusa Waterkeeper says human-source markers found in Manuel's Branch, urges more testing and public warnings

Calusa Waterkeeper representatives told the Fort Myers Environmental Advisory Board that their recent source-tracing study found repeated bacterial exceedances in Manuel's Branch and detected indicators consistent with human sewage.

"We've confirmed over a number of tests that there's a human source to that contamination," said Jason Pim, a Calusa Waterkeeper board member and the group's advocacy committee chair, describing HF183 DNA-marker and sucralose tests that came back positive at multiple outfalls. He and volunteer Ken Cherneski said the findings point to several potential point sources, including a lift station adjacent to a trailer park and discharges near the park's public access.

Pim and Cherneski summarized a two-phase approach: walking the channel to identify outfalls and then running third-party tests for human-source markers at sites with high indicator-bacteria counts. "Three of three surface-water locations we tested where there was HF183 positive also tested positive for sucralose," Cherneski said, describing redundancy between the DNA marker and artificial-sweetener tests.

City staff acknowledged the city's own historical E. coli sampling but stressed differences in testing approaches: county/city sampling focused on a single downstream station reported monthly, while the Waterkeeper team used enterococci and targeted point-source sampling to increase spatial resolution. Environmental compliance manager Mahone told the board the city has been sampling monthly for years and that dredging and infrastructure repairs have cost and logistical constraints.

Presenters recommended several near-term actions: (1) increase focused human-source tracing (more frequent HF183 and sucralose testing, and replication to meet statistical thresholds); (2) inspect and, if necessary, dye-test lift-station infrastructure at the trailer park; (3) post clearer, more prominent health-warning signage at Manual's Branch Park and other informal access points; and (4) consider targeted vegetation maintenance to improve sunlight penetration where appropriate. They also urged the city and Florida DEP to coordinate on an agreed sampling plan so data are comparable.

Board members pressed for details on methods and resources; city staff said some remedial options (dredging, structural repairs) have been proposed to DEP and may be eligible for grant funding but require substantial expense. The board and presenters agreed to ask the city to identify a staff liaison for ongoing data-sharing and to pursue focused investigations on the sites Calusa Waterkeeper highlighted.