The Hernando County Health Department has long contended that runoff has caused the high bacteria counts that have repeatedly closed Rogers Park.
After heavy rains, the agency said, water carried contamination from swamps, roads and yards to the park, on the Weeki Wachee River just east of Shoal Line Boulevard. It happened most recently last week, when the department ordered the park to be closed after measuring elevated levels of fecal coliform.
The department now has identified another possible contributing factor _ septic tanks. Stephen P. Henry, who rents a house on Bear Trail near the river, discovered a sewer backup in his house on July 8, said Kay Adams, director of the county's Utilities Department.
A plumber fixing the problem found that the house was not hooked up to the county's sewer system _ though Henry had been paying the county for sewer service _ but to a collapsing septic tank that was probably contributing to the river's pollution.
The house Henry rents has since been hooked up to the county sewer line. But its circumstances raises the question of whether other homes have also dumped effluent in the river.
It's possible, but not likely, Adams said.
"We don't really think there's a lot of them out there," she said.
She said homes in the area were connected to a sewer line in 1977. Judging from minutes of County Commission meetings at the time, the process was thorough and it is unlikely many homes were bypassed, she said. Also, homeowners would not have agreed to pay monthly utility bills unless they were sure their homes had been connected.
"There was an effort to get them all off the septic tanks and onto sewer lines," Adams said. "The county went ahead and got some grant money and some loans and put sewer lines in throughout the Weeki Wachee area."
Al Gray, environmental manager at the health department, said his agency has tested the river and has not found that the bacteria comes from any concentrated source.
"As far as we can determine, there are no point sources of contamination in that area," Gray said.
"We were informed that there was one septic tank that was out there," he said.
Adams said the Utility Department has conducted smoke tests on the sewer treatment system to determine if it had any leaks that contributed to the contamination. It found none, she said.
It will now run television cameras through the lines to make sure all are hooked up to homes. Because she does not think the danger of contamination is pressing, workers will do this when time is available.
"We're going to sit down and figure it out and chart it out," she said. "This will be done as time allows."
Fecal coliform is a type of bacteria that can cause vomiting, nausea, and infections of the eyes, ears, nose and throat. Though other types of bacteria can come from decaying vegetation, animal waste is the only source of fecal coliform.
Both Gray and Adams said they are still convinced that wild and domestic animals _ not humans _ caused the problem.
The health department will continue testing water at the park regularly until bacteria content returns to a safe level, Gray said.