Water quality from water supply wells depends on many factors, including the nature and thickness of the soils in the area of the well, the type of well, and sources of pollution in the vicinity of the well.
The map below shows possible sources of groundwater and surface water pollution
in the Unity area. Are there a lot? Compared to many communities,
no! Many communities in Maine have more possible pollution sources
than Unity, and most of these sites have been cleaned up or are licensed
and carefully regulated by the Maine Department of Environmental Protection.
Most of these sites pose little or no threat to water quality.
|
In most communities, it is more often individual actions that produce cumulative threats to water quality, rather than particular licensed and regulated facilites; septic systems and fertilizer usage may be greater sources of pollution than regulated biosolids application sites. How can we measure the effects of these, and distinguish them from natural controls on water quality?
The potential for groundwater pollution may be related to population density and soil type and thickness. The sand and gravel aquifer in downtown Unity, deposited by a glacial-meltwater river about 20,000 years ago, would allow pollutants to percolate down to groundwater, but clay soils east and west of town, deposited in shallow ocean water at about the same time, would be less likely to allow pollutants to flow to the bedrock aquifer that most of the town uses for a water supply.
This term, Geology of Environmental Problems students are beginning a study of well water quality in the Unity Pond watershed. Although this study will take many years to complete, when it is done residents of the watershed will have a complete picture of the drinking water quality around the lake, and of the human and natural variables that control drinking water quality.
Check back here often to view maps of important water quality components,
such as iron, nitrate, sulfate, and chloride, in the watershed.
|
|
|