Ohio Administrative Code
Title 3745 - Ohio Environmental Protection Agency
Chapter 3745-9 - Water Well Standards
Section 3745-9-06 - Well construction, specific geologic conditions
Universal Citation: OH Admin Code 3745-9-06
Current through all regulations passed and filed through December 16, 2024
(A) In addition to the requirements of rule 3745-9-05 of the Administrative Code, a well completed in specific geologic conditions shall be constructed according to the following procedures:
(1)
Where consolidated formations are encountered within twenty-five feet of the
ground surface, an oversized borehole shall be drilled and the annular space
shall be filled with grout by pressure grouting.
(2) A well completed where multiple aquifers
are present shall have the casing extend through aquifers that are not
contributing to the water supply of the well. The annular space contiguous to
aquifers that are not contributing to the water supply of the well shall be
filled with grout by pressure grouting.
(3) A well completed in confined aquifers
shall have the casing extend through the confining layer to the top of the
aquifer. The annular space contiguous to the confining formation shall be
filled with grout by pressure grouting. Filter packs and formation stabilizers
shall not extend significantly into a confining formation or allow
interconnection of two separate aquifers along the annular space.
(4) A well completed in aquifers with
hydrostatic heads greater than the land surface elevation shall have casing and
grout installed to protect the aquifer, prevent erosion of the overlying
geologic materials and confine the flow to within the casing, and shall be
constructed according to the following procedures:
(a) If the anticipated flow at the ground
surface is not excessive, after the borehole is drilled, and the casing set,
the water in the casing may be pumped to lower the water level in the casing
and the annular space. The annular space shall then be filled with cement grout
by pressure grouting. The density of cement grout shall be sufficient to
control flow in the annular space, but no less than that required by rule
3745-9-07 of the Administrative
Code.
(b) If the water flow at the
ground surface is anticipated to exceed five gallons per minute, an upper
enlarged borehole shall be drilled partially into the confining formation. The
upper enlarged borehole shall be at least four inches in diameter larger than
the nominal diameter of the outer well casing. The annular space between the
upper enlarged borehole and outer well casing shall be filled with cement grout
by pressure grouting. The outer casing may be left as permanent casing once the
well is completed, or it may be removed. Where outer casing is not removed, the
casing shall be withdrawn at least five feet to ensure grout contact with the
formation.
(i) If the confined aquifer is
consolidated, a smaller diameter borehole shall be drilled through the upper
enlarged borehole, the inner casing shall be firmly seated into the bedrock,
and the remaining annular space shall be filled with cement grout by pressure
grouting. The density of cement grout shall be sufficient to control flow in
the annular space, but no less than that required by rule
3745-9-07 of the Administrative
Code.
(ii) If the confined aquifer
is unconsolidated, a smaller diameter borehole shall be drilled through the
upper enlarged borehole, with casing and a screen installed into the confined
aquifer. The well shall be double-cased, and the remaining annular space filled
with cement grout by pressure grouting. The density of cement grout shall be
sufficient to control flow in the annular space, but no less than that required
by rule 3745-9-07 of the Administrative
Code.
(c)
Flowing wells shall be completed at the surface to
ensure water does not flow from under the well cap.
(d)
Flowing well
discharge control shall be provided to conserve ground water and to prevent the
loss of artesian head by preventing or reducing continuous discharges. Flow
control shall consist of one of the following methods:
(i)
The extension of
the well casing to an altitude corresponding to that of the artesian
head.
(ii)
Installation of a vermin proof cap, well pitless
adapter or wire spud, or a point of discharge that complies with paragraph
(A)(4)(e) of this rule.
(iii)
Installation of flowing well or spool type pitless
unit, when installed within the manufacturer's specification for rated
pressure.
(iv)
Other methods approved by the Ohio EPA.
(e)
After
all uses for the public water system are met, flowing wells may discharge up to
ten gallons per minute when the public water system's owner demonstrates that a
suitable discharge point exists on the owner's property, that the flow control
discharge line can be adequately protected from any possible cross connection,
and when one of the following conditions exist:
(i)
Control of the
flow is not practical due to excessive hydrostatic pressure.
(ii)
Control of the
flow will likely result in the production of sand or turbidity in the
water.
(iii)
The discharge will not adversely affect surrounding
users of ground water or impact surface water drainage.
(iv)
The discharge
line from the well shall either be protected by an air gap with an animal guard
or a backflow prevention device.
(5) A well completed in a cavernous formation
or mine shall be constructed according to the following:
(a) A cavernous formation or mine that is not
being used as a source of water shall have casing installed through the
formation or mine, as follows:
(i) If a
cavernous formation or mine is greater than twenty-five feet below ground
surface, then the formation or mine shall be filled with cuttings, clean gravel
or grout. Packers or shale traps shall be installed at the top and bottom of
the formation or mine. The annular space shall then be filled with grout by
pressure grouting.
(ii) If a
cavernous formation or mine is less than twenty-five feet below ground surface,
casing shall be installed in an enlarged borehole and the annular space shall
be filled with a cement grout containing additives that promote bridging of the
cavernous formation or mine by pressure grouting to a depth of at least five
feet beyond the formation or mine.
(b) If a cavernous formation or mine will be
the source of water supply, then a packer or shale trap shall be installed at
the top of the formation or mine and the annular space shall be filled by
pressure grouting with grout.
(6) A well encountering brine producing
formations shall be constructed according to these procedures. Brine producing
formations that are encountered during drilling shall have casing installed
throughout the entire formation. The annular space contiguous to the brine
producing formation shall be filled with grout by pressure grouting, or the
well shall be sealed to an elevation higher than the top of the brine producing
formation. Grout that is not adversely affected by the brine water shall be
used for sealing the well or annular space.
(7) Except when a well is completed in the
upper-most weathered portion of a consolidated formation, a well completed in a
consolidated formation shall have the casing extend into the formation so that
the well casing will not settle or shift, and will have a proper annular
seal.
Disclaimer: These regulations may not be the most recent version. Ohio may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.
