The streams feeding Lake George on either side of Shepard Park Beach create a large whirlpool, forming a backwater that may be recirculating the polluted water, he said.
Also,the village's aging sewer pipes may be corroded or broken by tree roots, allowing not only infiltration of stormwater that overburdens the sewer system, but is allowing polluted water to seep out and pollute the lake.
"No one should rule out that the sewer system is not working properly," he said, noting that when rain falls, the volumes of effluent in the sewer system is boosted by 30 to 40 percent.
While some have blamed the continuing bacteria levels on stormwater washing dog or bird feces into the lake, the contamination is greater than could be caused by such sources, he said.
But Village Mayor Robert Blais said Tuesday that the high coliform counts could indeed be from waterfowl, because since the beach was closed to humans July 5, birds have taken over. He said that Darrin Fresh Water Institute was now conducting tests to determine in the bacteria was generated by waterfowl or humans.
Salvadore said the village's sewer system should be re-engineered and the Lake George Consolidated Board of Health should be involved in planning the project.
The sewer system now has a lower main transmission line that runs along the shoreline in the village, gathering wastewater - via gravity-fed lines - from lakefront motels and enterprises.
This sewer main should be relocated away from the lake and set along Canada Street, and the lakefront businesses should be pumping their effluent up to the relocated main, he said.
But Blais countered Tuesday that the lakeside water mains were likely intact.
These sewer lines in the vicinity of Shepard Park Beach had new impervious linings installed about three years ago, which should prevent any leakage there. South of the beach, brand-new lines were installed about 12 years ago when the lakefront walkway was constructed, he added.