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By Erin Post
For the most part, Valley residents depend on cracks in the bedrock-sometimes hundreds of feet below the earth's surface-for the water that spills out of their faucets at the flick of a wrist.
It's the region's steep-sided mountains and shallow soils that make these fractures so important, said Eric Hanson, a groundwater specialist with the Vermont Rural Water Association. Since topography limits the number of sand and gravel deposits in the Valley-a reliable water source for many other communities--hitting a crack in the bedrock where groundwater collects is often a person's best bet when searching for water here.
He urged Valley residents to prevent future problems with their water supply by taking an interest now.
"Everything does count and we should do what we can to protect our groundwater resources," he said.
Hanson spoke to a packed gymnasium at the Waitsfield Elementary School April 2 along with Liz Royer, a source water specialist, in the first of two forums on drinking water sponsored by Friends of the Mad River (FMR).
FMR president Kinny Perot said the organization hopes to eventually work with a geologist to map groundwater resources in The Valley. She said such projects are required by state law, although, so far, state funding has been non-existent.
Private homeowners may sign up to test the quality of their water at a discounted rate at either the next water forum later this spring or by contacting the FMR office. The FMR provides bottles and ships the water samples to a lab for analysis.
Results from these tests may help a future Valleywide groundwater mapping project.
As The Valley continues to grow, many towns are dealing with water-related issues, Perot pointed out. The town of Waitsfield recently drilled a test well off Reed Road for a possible public water source; in Warren, ski area expansion has led to more exploration for water supplies. In Moretown, MTBE contamination in some wells was a recent problem, Perot said.
Because Valley residents depend on fractures in the earth to feed their wells, Hanson said vast differences in the quality and quantity of water may exist between wells in the same neighborhood, and even in the same type of bedrock.
It all depends on the particular fracture the drill taps.
Bedrock type influences levels of some naturally occurring pollutants, including arsenic, radon and uranium, Hanson said. In some cases, wells have been drilled and abandoned because of contamination levels.
"When you're in that bedrock type, there's not much you can do about it," he said.
Man-made contaminants include herbicides, road salt, and bacteria from failed septic systems. At high enough levels, these contaminants may percolate through the soil and seep into the groundwater supply at a given location.
Many variables come into play when dealing with contaminants, including soil and bedrock type as well as topography. In general, however, soil acts as a natural filter that keeps groundwater relatively untainted.
"In general, soil is a miracle filter," Hanson said.
Because groundwater and surface water exist in a cycle, the state monitors whether wells draw enough groundwater to affect nearby rivers and streams. Groundwater is often crucial to "recharging" streams and rivers, adding to rain and snowmelt.
"Those kinds of issues are starting to happen more than they have in the past," Hanson said.
RECOMMENDED TESTS FOR DRINKING WATER
The state recommends private well owners conduct several tests regularly, said Liz Royer, a source water specialist with Vermont Rural Water Association. These include:
A total coliform bacteria test annually to measure a "large group of soil and intestinal bacteria that indicate potential well contamination."
Inorganic chemical test every five years to measure levels of arsenic, chloride, iron, lead, and other naturally occurring contaminants.
Gross alpha radiation screening every five years. This screening tests for "mineral radioactivity," including uranium and radon.
The state regulates "public water supplies," defined as wells serving more than 25 people at least 60 days per year. Some restaurants and businesses as well as housing developments fall into this category, Royer said.
She said for these systems, the state requires protection plans to map source waters and identify potential pollutants.