By ADAM ASHTON
Aging and failing septic systems near creeks that feed into Pine Mountain Lake could pose a future threat to water quality in the area, according to a Groveland Community Services District draft report.
The report, conducted by Irvine-based RBF Consulting, recommends consistent water quality monitoring by GCSD to determine the source of fecal coliform bacteria in lake tributaries, including Big Creek and Garrotte Creek.
But GCSD General Manager Jeff Winner said the report does not suggest an immediate problem for the Groveland area.
"We didn't find evidence of a chronic issue," Winner said. "A lot of the information makes you kind of go 'hmm,' but hopefully we've caught this before it becomes a water quality issue."
Tuolumne County Health Department and Pine Mountain Lake Association officials say the area is not experiencing an unexpected number of septic failures. They said the report could encourage residents to press for more GCSD sewer connections around the lake.
Winner said at least three septic systems have failed in the Groveland area this summer.
He said an increasing number of septic failures would lead to GCSD actions that could include bringing new sewer lines to homes that now have private septic systems.
"A lot of (septic systems) are getting old and are at the end of their useful life," he said.
The highest areas of concern are homes with septic tanks along Big Creek, where fecal coliform bacteria was found consistently in the creek's drainage area.
Though the report states its findings are inconclusive, it indicates the creek "may be experiencing water quality deterioration due to septic systems in the area."
The report notes the highest levels of coliform bacteria in the creeks are found after the first rains. Because animals can carry the bacteria, the report does not say humans definitely are the cause for the bacteria's presence in and around the lake.