SARANAC LAKE - The village of Saranac Lake's soon-to-be-new source of drinking water was not contaminated by the recent flooding of the Saranac River and will be protected from future flooding by the design of the state-mandated $10.7 million water project.
That's according to a report that Chris Lawton of Barton & Loguidice, the village's engineering firm on the project, sent last week to village Manager John Sweeney.
Based on concerns raised at a May 9 village board meeting, Lawton was asked to investigate what impact, if any, the flooding had on the two wells that were drilled last year behind the village wastewater treatment plant, and what's being done to ensure they're protected in the future.
The low-lying area where the wells are located was inundated with as much as a foot-and-a-half of water from the river in late April and early May. It's also a short distance from the wastewater treatment plant, part of which was overwhelmed with water, causing partially treated sewage to be released downstream.
Lawton's report, however, says the aquifer that will be the new village water source is protected from potential surface water contamination by layers of "fine-grained, lower permeability sediments" like clay and peat. The aquifer is also "capped by a confining layer over a broad area around the wells," he wrote.
The wells are protected from surface water contamination by a cement grout seal that runs 28 feet below the ground. Lawton's report also notes that the top of the well casings are about 3 feet above the river's 100-year flood elevation.
The combination of all those things "provides for excellent protection against the potential surface water impacts due to flooding or any surcharges from the village's (wastewater treatment plant)," Lawton wrote. He noted that independent testing of the two wells after the recent flooding found they "are not under the influence of surface water."
State Health Department officials have made the same determination.
"Those wells are deep-drilled wells and there's quite a layer of protection, so there is no direct surface influence," DOH Public Health Engineer Susan Kennedy, who works out of the Health Department's Saranac Lake office, said Monday. "I don't believe the quality of the water was compromised in any way during this flooding."
To protect the wells from future flooding, the project's design calls for raising the ground elevation in the area where the wells are located. The village plans to use roughly 6,500 cubic yards of sand and gravel mined from village-owned property behind the wastewater treatment plant to raise the area around the wells between 3 and 5 feet, according to Lawton's memo.
Kennedy said the Health Department requires the top of the well casings to be well above the 100-year flood or highest known flood levels. Based on an initial review of the village's design, "I do believe the proposed elevation of the water treatment plant is appropriate," she said.
Culverts will also be installed along the access road to let water get from one side to the other. And the well pumps will have to go through an extensive disinfection process before they're activated, Kennedy noted.
In addition to those measures, Sweeney said the village board agreed Monday to hire the New York Rural Water Association for $5,520 to create a wellhead protection plan that will identify potential sources of contamination near the wells and list a series of protection measures.
"All these pieces put together, from the extra fill to be brought in there, the wellhead protection plan and our engineer's response, pretty much addressed all of the open questions," Sweeney said Tuesday.
Some people, including members of the village board, have questioned the decision to put the wells so close to a potential source of contamination like the wastewater treatment plant. But Kennedy noted that the wells are upstream from the plant, and in the case of the recent discharge of partially treated sewage in the river, "the contamination was flowing away from the wells."
"Why did they drill in this area? Well, because this is where the water is," Kennedy said. "This is where you do find high-yielding wells. Saranac Lake is so fortunate to have found these incredibly high-yielding wells."
The site was also picked because it was property the village already owned, Kennedy noted.
The overall design of the water project doesn't have final Health Department approval, but Kennedy said that review is under way.
"We're going to be working hand in hand with the engineers to make sure the plan will provide for the sanitary protection of the wells," Kennedy said. "We're very comfortable that can be easily done."