(A) Water from a well has not always been underground. As rainfall and surface water absorb into the soil and migrate through the subsurface, other substances are dissolved. A well's recharge area (where surface water enters the ground) and the aquifer (the underground area which contains the water) may extend for thousands of feet from the well. Thus pollutants from the surface or underground may travel great distances.
(B) The speed of this travel varies from inches per year to feet per day, depending on the soil and rock structure. In some areas layers of impervious material may create a confined aquifer. These areas are at less risk than those with unconfined aquifers where surface water penetrates directly. However, even confined aquifers may be contaminated at the recharge area, through imperfections in the confining layers, or by penetrations such as wells or around well casings. The area closest to a well presents the greatest risk because of the suction produced by pumping.
(C) Until recently wells and springs were thought to be relatively immune to contamination. The phrase "Water purifies itself every so-many feet" is a widely accepted misconception which has sometimes been used to justify ignoring potential pollution sources. As many communities have learned, many substances of concern to health are not rendered harmless as they migrate underground.
(D) Once a contaminant has entered the groundwater, it is far more difficult and costly to remove than when it was on the surface. If the aquifer is contaminated, drilling another well may not be an alternative. Direct costs (for alternate water supply, cleanup, consulting fees, loss of water sales) are staggering; indirect costs (health consequences, loss to property values and tax base, ability to attract business, possible job loss,) even greater.
(E) Prevention is a far better alternative.
(Ord. 00-19, passed 12-11-2000)