Wells should be lined, or "cased," with welded
lengths of steel pipe, which are grouted in place. Since the outside
surface of the well casing is a direct conduit to the aquifer the top
of the well should be surrounded by a concrete pad and tightly capped,
Do not spread or store fertilizer, pesticides, petroleum products,
orother chemicals in the zone around the well.
The wellhead area should be landscaped so that standing water
cannot accumulate around the well.
Never pump a new limestone well at high rates (greater than
200 gallons per minute) unless aquifer tests have
been conducted by a qualified hydrogeologist. In some areas, excessive
pumping of karst wells has caused ground subsidence, sinkhole collapses,
and de-watering of neighboring wells and ponds.
Homeowners and prospective home buyers should be aware that
water well samples required for new well permits and property transactions
may be collected immediately after "shock" chlorination
treatment to disinfect the well. Such samples will not reveal the
of bacteria and other constituents that may be present after the
chlorine is pumped from the system. Re-testing is recommended.
Abandoned wells, old hand-dug farm wells, and cisterns often
represent direct connections between the surface and the karst
aquifer. Abandoned wells should be properly plugged with clean rock
water zone) and sand-cement grout (to the surface) to prevent runoff
directly to the groundwater. No wastes or debris should ever be
disposed in a well or in karst features near any well.
Test domestic wells for
coliform bacteria, nitrates, and other suspected compounds at
least annually, and keep a record of these as
a "background" for evaluating any future pollution. Also
record the dates that muddiness or low water level problems occur,
as current and previous climatic conditions.
Well drillers are required
to disinfect new wells with chlorine; attempts to use unapproved "cleansers" in
this process have contaminated aquifers for great distances.
health departments regulate the practice of well abandonment.
Be sure your driller follows
all applicable state permit guidelines for water well construction
Polluted and low-yielding wells can sometimes be rehabilitated
by a skilled driller who can acidify the well; "seal off" a
contaminated water zone with casing, packers, and grout; and re-drill
the well to a cleaner water zone (if one exists). Consult with
your neighbors about the depth and quality of their water wells,
as local well drillers, the health department, and geologists before
attempting to re-drill a water well.
If contamination is suspected
or is a threat, a specific study to map land use patterns and
determine the direction and rate of groundwater
movement may be necessary. The information from such studies could
serve as the basis for long-term, local solutions to pollution.
local health department or state environmental agency for the names
of environmental consultants, non-profit organizations, universities,
watershed groups with experience in this area.