Current through September 24, 2024
(1) The driller or
person holding a license for well closure shall backfill and close any newly
drilled water well not intended for use in which casing has not been installed
or from which casing has been removed, within fifteen (15) days after the drill
rig leaves the site. The driller shall take all steps necessary to maintain
safety around the site until the closure process is completed. Prior to closing
any such well, the driller shall:
(a) Remove
all equipment or material that may obstruct access to the bottom of the
well;
(b) Check the entire depth of
the well for obstructions that may interfere with sealing operations and remove
them, and
(c) Thoroughly chlorinate
the well prior to sealing by the addition of sufficient quantities of liquid
bleach or dry hypochlorite granules to produce a free chlorine residual of
twenty-five (25) parts per million (ppm).
(2) Except as provided in paragraphs (3),
(4), (5) and (6) of this rule water well plugging and closure shall be
accomplished by a licensed driller by the following methods:
(a) For uncased water wells, a cement grout
or bentonite as defined in subparagraph (c) of this paragraph or other grout
material approved by the Department shall be placed in the well bore from two
feet below land surface to a minimum of twenty-five (25) feet below land
surface. Native soil may be used to backfill the borehole from land surface to
two feet below land surface or the driller may use cement or bentonite to land
surface. The well bore twenty-five (25) feet below land surface shall be filled
with either bentonite, cement grout, clean crushed stone one half inch in
diameter or less, well cuttings, puddled clay, sand or combined mixture of any
of these listed materials. Backfill shall remain level with land
surface.
(b) For water wells with a
minimum of nineteen feet of casing installed, a surface plug consisting of
either cement grout or bentonite as defined in subparagraph (c) of this
paragraph shall be placed in the well bore from land surface to a minimum of
five (5) feet below land surface. An additional seal of cement grout or
bentonite as defined in subparagraph (c) of this paragraph shall also be placed
in the well bore for a minimum length of ten (10) feet. The top of this ten
(10) foot seal shall either be located within twenty (20) feet below the bottom
of the casing or at the top of the well screen or perforated pipe. The
remaining well bore or casing shall be backfilled with either bentonite, cement
grout, clean crushed stone one half inch in diameter or less, well cuttings,
puddled clay, sand, or combined mixture of any of these listed materials.
Surface casing may be terminated two (2) feet below land surface and native
soil may be placed in the well bore from two feet to land surface provided that
the upper surface plug of cement or bentonite grout is placed in the borehole
from two to seven feet below land surface. Backfill shall remain level with
land surface.
(c) The grout
material used in the plugging and abandonment of a water well shall consist of
a grout material approved by the Department or a mixture consisting of Portland
Class A cement or quick setting cement in a ratio of not over six (6.0) gallons
of water per ninety-four (94) pound sack of cement, or a high solids bentonite
grout with a minimum of 20% solids and a weight of no less than nine and two
tenths (9.2) pounds per gallon as measured by a standard mud balance. The use
of bentonite, in chip or tablet form, ranging in size from one-quarter inch
(1/4") to three-quarters (3/4) of an inch will be allowed as an alternate seal
to slurry grouting. The bentonite shall be mixed and applied in accordance with
the manufacturer's recommendations. The use of low solids bentonite drilling
clay (designed for use as a drilling fluid to form a filter cake on the side
walls of the borehole and to increase viscosity of water) is prohibited for use
as a grout or sealing material except as an additive. If bentonite is used as a
sealing material only bentonite grout, bentonite tablets, or bentonite chips,
approved by the National Sanitation Foundation (NSF) or American National
Standards Institute (ANSI) certified parties as meeting NSF product standard 60
or 61 shall be approved by the Department as appropriate grouting or sealing
material.
(d) Placement of the
backfill material shall be done in such a way that there are no bridges or gaps
in the well bore. The top of the backfill material shall remain level with land
surface.
(3) Wells
extending into more than one aquifer shall be filled and sealed in such a way
that exchange of water from one aquifer to another is prevented.
(4) The sealing of flowing wells shall be
accomplished only after the wells have been treated to reduce the flow to zero.
This may be accomplished by introducing high specific gravity fluids which are
approved for use in potable water systems into the bottom of the well bore and
continuing until the flow ceases.
(5) The driller or a person holding a license
for well closure may submit a written petition for an alternative method of
well abandonment. Any alternate method of filling and sealing a well shall be
submitted to the Director for review and written approval prior to sealing a
well by such method. In an emergency or in exceptional instances, the
Department will respond to a verbal request provided the applicant submits a
written application within ten (10) days of the verbal application.
(6) Hand dug water wells greater than twelve
inch in diameter without steel or plastic casing and less than sixty (60) feet
in depth may be abandoned by a landowner, or the following individuals licensed
in Tennessee: licensed engineers, licensed professional geologists, licensed
building contractors, licensed pump installers, county environmentalists, or
environmental specialists for the state of Tennessee. They must all follow the
construction standards for the closure of a hand dug well. The landowner should
contact the Division of Water Resources or a licensed driller prior to closing
a hand dug well for additional technical assistance. The person, other than the
landowner closing the hand dug well is responsible for submitting the well
closure report for the hand dug well. A landowner who does the well closure is
not required by law to complete a well closure report: however it is
recommended that the landowner submit a letter to the Division of Water
Resources similar to information submitted on a well closure report. The
information serves as a public record of the landowners' compliance with state
well construction standards and will be important information for land
appraisals and property transfer arrangements. No matter who does the job, the
landowner is ultimately responsible for the closure of a hand dug
well.
(7) Hand dug water wells may
be closed by using the following procedures:
(a) Thoroughly chlorinate the well prior to
sealing by the addition of sufficient quantities of liquid bleach or dry
hypochlorite granules to produce a free chlorine residual of twenty-five (25)
parts per million within the entire well.
(b) Cement grout or bentonite as defined in
subparagraph (2)(c) of this rule must be used from five feet to two feet below
land surface to place a barrier for the well. The remaining annular space from
two feet to land surface may be filled with native soil or cement. Backfill
must remain level with land surface.
(c) Construction debris, trash or wood are
prohibitive materials and must never be used during the well closure
process.
(d) Native soil material,
gravel less than one inch or less in diameter, cement or bentonite may be used
as well closure material from five feet below land surface to the total depth
of the well.
(8) All
well closure reports shall include a diagram showing the location and distance
in feet of the closed well from one specific landmark and septic system or
sewer systems on the property.
(9)
Well Abandonment-Existing Wells with Obstructions
(a) Existing wells required to be closed for
which no well construction report is on file and/or those that are partially
filled or obstructed with soil, rock, construction debris or other materials
must be cleaned out inside the well down to a minimum depth of twenty-five (25)
feet below land surface to allow for proper sealing of the upper terminus of
the well.
1. If the well does not open up and
remains filled below twenty-five (25) feet, the well shall be backfilled and
sealed from twenty-five (25) feet to land surface with a cement grout or
bentonite as defined in subparagraph (2)(c) of this rule.
2. If the well opens up below twenty-five
(25) feet while cleaning, the well shall be backfilled from its lowermost open
depth to twenty-five (25) feet below land surface with either cement grout,
bentonite, clean crushed stone one-half (1/2) inch diameter or less, well
cuttings, puddled clay, sand or a combined mixture of any of these materials.
Cement grout or bentonite as defined in subparagraph (2)(c) of this rule shall
be used to backfill the well from twenty-five (25) feet to land
surface.
(b) If the
grading or elevation changes are expected at the site, native soil or crushed
rock can be used to backfill the well from land surface to two (2) feet below
land surface.
(c) The driller will
be required to file a well closure report with the Department within sixty (60)
days of the completion of the well abandonment.
Authority:
T.C.A. §§
69-10-101 et seq. and 4-5-201 et
seq.
