Private Well Testing Program
A number of factors influence a well’s susceptibility to contamination. Well location and construction are of maximum importance. The well should be located away from potential sources of contamination, such as septic systems; livestock yards or barns; landfills or dumps; above-ground or underground fuel storage tanks which might possibly leak; areas where pesticides, herbicides or fertilizers are mixed; and low-lying areas which may be subject to flooding during times of runoff.
Groundwater itself may become contaminated in a number of ways. The most common way for this to happen is through the influence of contaminated surface water. Shallow aquifers can come under the influence of surface water if a stream, river, pond or lake is near. Flooding from spring runoff, or runoff from fields which have been fertilized or have had pesticides or herbicides sprayed can also threaten groundwater. Spilled organic compounds, such as fuels, solvents, pesticides and herbicides can be carried by surface water as it percolates through the soil to an aquifer. Aquifers may be contaminated by surface water which leaches heavy metals from mines, nitrate and bacteria from septic systems or livestock yards, and various kinds of organic compounds from landfills. Abandoned but unsealed wells provide easy access for contamination carried by rodents, flood or runoff water, or from improper disposal of waste or refuse in the well.