Mirror Lake salt survey follow-up underway

LAKE PLACID – Brendan Wiltse of the Ausable River Association has a message for concerned community members who see small groups out drilling holes in the center of Mirror Lake throughout the remainder of winter.

There may not be a need to call the Department of Environmental Conservation or village police, because Wiltse and his team are not ice fishers. Rather, they’ve begun the additional testing the Mirror Lake Watershed Association received funding for last month from the village and town.

Last weekend, with temperatures a bit higher than normal, Wiltse said the DEC and village police received concerned phone calls of people ice fishing, when in actuality it was him and his team beginning the recently approved sampling.

Late last year, the Ausable River Association issued a Mirror Lake Water Quality Monitoring Proposal outlining how 2015 sampling efforts and research in the lake show road salt pollution is negatively affecting the bottom waters of the lake.

Last month, the town of North Elba board approved $2,000 for the study, the village of Lake Placid board approved $1,500 and the MLWA also received $1,000 in private funding. Wiltse said the funding for additional winter and spring testing is necessary to validate 2015’s results.

“We’ve found evidence there is higher salinity at the bottom of the lake,” Wiltse said. “It’s something we are concerned about, because it’s something that should not be occurring in Mirror Lake.

“The big thing here is if it is impacting lake turnover in the spring,” he added. “The turnover is important for fish.”

The association says Mirror Lake’s fish may be deprived of oxygen in the summer season due to the higher salt concentration at the bottom of the lake, thanks to salting of roads and sidewalks in the winter.

Wiltse said the association will have results to present sometime in the spring.

Throughout the winter, testing and sampling will be conducted once a month. The sampling is conducted by drilling a 4-inch hole in the ice and lowering down a probe that records temperature, dissolved oxygen, dissolved salt content and pH: the measure of acidity and alkalinity in the water.

Conducting the sampling at the center of Mirror Lake’s surface, the association is able to test to its deepest depth at 18 meters.

“The work this winter will help us understand how and why there is the difference in salinity from the surface to the bottom of lake,” Wiltse said.

The lake’s upper and lower levels will turn over this coming spring at 39.2 degrees, or 4 degrees Celsius, when water is most dense. Throughout the spring and summer, the association will continue its testing to see if the salt concentration at the bottom is inhibiting that natural turnover.

When ice is no longer on the lake, the sampling will be conducted every two weeks through summer, Wiltse said.