CHALLENGE
A private well in Pittston, Maine was discovered to have elevated salt levels that were attributed to an outdoor municipal road salt storage area about 0.25 miles away. In Maine, municipalities are liable for road salt contamination from their road application or storage sites. With consultation from St.Germain, the Town decided that water treatment for the entire residence was cost prohibitive because their responsibility would essentially never end, so a new well was required. However, unless the groundwater pathway from the salt storage site to the contaminated well was determined, a new well could also become contaminated with salt.
RESPONSE
St.Germain contracted with a specialty geophysical survey company to conduct a borehole geophysical survey down the well. The survey included measurement of temperature, borehole diameter, conductivity, and the location and orientation of bedrock fractures.
With these data, St. Germain identified the fracture in the well where the salt water was entering. By projecting this feature to the ground surface, we identified an area on the residential property distant from this salt-bearing fracture. A new well was drilled with very low salt levels that was subsequently connected to the residence.
