(1) CONTROL OF FLOW. When a well driller or
well constructor constructs a flowing well, the flow shall be confined to the
interior of the well casing. When the flow of water is not contained to the
interior of the well casing using planned construction methods, the well
driller or well constructor shall notify the department of the location of the
flowing well immediately, and take one of the following actions:
(a) Reconstruct the well to contain the flow
to the interior of the casing.
(b)
Fill and seal the well according to one of the methods specified in s. NR 812.26 (6) (i).
(2)
GENERAL REQUIREMENTS. A flowing well constructed with an upper enlarged
drillhole shall be grouted in accordance with par. (c). When a new well is
constructed to replace a well with uncontrolled flow, the well shall be
constructed to meet all of the following requirements:
(a)
Upper enlarged drillhole
requirement. An upper enlarged drillhole shall be constructed in
accordance with the requirements specified in subs. (3) or (4).
(b)
Driving or advancing
casing. Steel well casing shall be driven or advanced only through the
bottom of an upper enlarged drillhole constructed in accordance with the
requirements specified in subs. (3) or (4). The upper enlarged drillhole shall
be kept filled with drilling mud with a mud weight of at least 9 pounds per
gallon or with dry granular bentonite, which shall be maintained around the
outside of the casing. Approved drilling additives may be added to the drilling
mud to increase the mud weight.
(c)
Grouting requirement. The annular space of a flowing well
shall be grouted with neat cement using the methods specified in s. NR 812.20.
(3) CONSTRUCTION
REQUIREMENTS IN UNCONSOLIDATED FORMATIONS. In addition to the general
requirements of this section and the requirements specified in ss. NR 812.10 to
NR 812.13, a well driller or well constructor shall construct or reconstruct a
flowing well in unconsolidated formations according to all of the following
requirements:
(a)
Upper enlarged
drillhole. An upper enlarged drillhole shall be constructed to at
least 25 feet or halfway through any known confining bed, whichever is deeper,
except when the well is double cased in accordance with par. (e).
(b)
Minimum diameter. The
upper enlarged drillhole shall be a minimum of 4 inches larger than the nominal
diameter of any casing to be grouted, except as allowed under par.
(e).
(c)
Method of keeping
the hole open. The upper enlarged drillhole shall be kept open during
construction using any of the following methods:
1. Driving temporary casing to the depth
specified in par. (a).
2.
Circulating drilling mud with a weight of at least 9 pounds per gallon.
Additives approved under s. NR 812.091 may be added to the drilling mud to
increase the mud weight.
(d)
Screens. A well screen
may be placed according to the requirements specified in s. NR 812.13 (4) prior
to grouting.
(e)
Double
cased wells. When a well is double cased, it shall be constructed in
accordance with all of the following requirements:
1. The nominal casing diameter of the outer
casing may be reduced to a minimum of 2 inches in diameter greater than the
nominal diameter of the inner casing when welded steel or flush-threaded
thermoplastic casing is used for an inner casing.
2. An upper enlarged drillhole shall be
constructed into the confining bed in accordance with par. (c).
3. The outer casing shall be placed in the
upper enlarged drillhole and grouted in place according to the requirements
specified in sub. (2). The grout shall be allowed to set for a minimum of 24
hours before drilling continues.
4.
A second upper enlarged drillhole shall be constructed to at least the minimum
casing depth for the formation encountered and in accordance with par.
(c).
5. The inner casing shall be
placed in the upper enlarged drillhole and grouted in place according to the
requirements specified in sub. (2). The grout shall be allowed to set for a
minimum of 24 hours before drilling continues.
(4) CONSTRUCTION REQUIREMENTS IN BEDROCK
FORMATIONS. In addition to the general requirements of this section and the
requirements specified in ss. NR 812.10 to 812.14, a well driller or well
constructor shall construct or reconstruct a flowing well in bedrock formations
according to all of the following requirements:
(a)
Upper enlarged
drillhole.1. An upper enlarged
drillhole shall be constructed to the minimum casing depth for the bedrock
formation encountered or halfway through any known confining bed, whichever is
deeper, except when the well is double cased in accordance with par.
(e).
2. When the depth to the top
of bedrock is more than the minimum casing depth for the bedrock formation
encountered, the upper enlarged drillhole depth may be reduced to 25 feet below
ground surface when steel casing is driven or advanced according to the
requirements of sub. (2) (b).
(b)
Minimum diameter. The
upper enlarged drillhole shall be a minimum of 4 inches larger than the nominal
diameter of any casing to be grouted, except when the well is double cased in
accordance with par. (e).
(c)
Method of keeping the hole open. The upper enlarged drillhole
shall be kept open during construction using any of the following methods:
1. Driving temporary casing to the depth of
casing setting or to the top of bedrock.
2. Circulating drilling mud with a weight of
at least 9 pounds per gallon. Approved additives may be added to the drilling
mud to increase the mud weight.
(d)
Seating casing. Any
casing set into an upper enlarged drillhole constructed more than 5 feet into
bedrock shall be driven to a firm seat prior to grouting the annular
space.
(e)
Double cased
wells. When a well is double cased in bedrock, it shall be constructed
in accordance with all of the following requirements:
1. The outer casing may be reduced to a
minimum of 2 inches in diameter greater than the nominal diameter of the inner
casing when welded steel casing is used as an inner casing. The minimum
diameter of an inner casing is 6 inches.
2. An upper enlarged drillhole shall be
constructed into the confining bed in accordance with par. (c).
3. The outer casing shall be placed in the
upper enlarged drillhole and grouted in place according to the requirements
specified in sub. (2). The grout shall be allowed to set for a minimum of 24
hours before drilling continues.
4.
A second upper enlarged drillhole shall be constructed to at least the minimum
casing depth for the formation encountered and in accordance with par.
(c).
5. The inner casing shall be
placed in the upper enlarged drillhole and grouted in place according to the
requirements specified in sub. (2). The grout shall be allowed to set for a
minimum of 24 hours before drilling continues.
