Download Connections, Pumps -- 4725.3150-3400 (PDF)

4725.3150 CASING CONNECTIONS AND CAPS.
This part applies to all wells and borings. Water-supply wells have more stringent standards for
connections to a well casing and are located in Minnesota Rules, parts 4725.4850 and 4725.5450.
Minnesota Rules, part 4725.4850 concerns pitless units, pitless adapters, and welded or threaded fittings;
and Minnesota Rules, part 4725.5450 requires a screened, down-turned vent on water-supply wells. The
rules do not require a vent on wells or borings other than water-supply wells, however, vents are
recommended on wells with pumps. Vents may be installed on wells or borings, but the vent must comply
with the standards of Minnesota Rules, part 4725.5450. The practice of drilling a hole through the casing
and protective-outer casing to “vent” a well, such as a monitoring well, is not an approved practice.
Components which replace a portion of the casing above 12 inches such as a “T” or coupling must be
materials meeting, or equivalent to, the casing standards.
Subpart 1. Casing connections and caps 12 inches above ground. A connection
or fitting 12 inches or more above the established ground surface into the top or
side of a casing must be constructed to be weatherproof and insect proof. The
connection, including a cap, cover, electrical connection, water treatment
connection, discharge piping, vent, access pipe, or other connection to the casing
must consist of:
A. a threaded connection;
B. a welded or solvent welded connection;
C. a rubber expansion sealer;
D. a bolted flange with rubber gasket;
E. an overlapping cap or cover with compression gasket;
F. an extension of the casing at least one inch into the base of a pump; or
G. a sanitary well seal with a one-piece top plate, compression gasket, and
noncorrodible draw bolts. The cap or seal must be equivalent to the casing in
weight and strength. If the well or boring is in a building that meets the
requirements in part 4725.2175, a two-piece top plate, compression gasket, and
noncorrodible draw bolts may be used.
Minnesota Rules, part 4725.2175 requires that a well or boring must not be within a building unless the
building (well house) meets all requirements of Minnesota Rules, part 4724.2175. Subpart G requires a
sanitary seal installed outdoors to have a one-piece top plate.
The casing connection requirements of this part apply to the well or boring at completion. Minnesota
Rules, part 4725.2250, subpart 16, requires the casing to be temporarily covered by one of the methods
listed, during the construction process when actual construction is not occurring. The temporary cover
must be weatherproof and insect proof. Tape, bags, upside down buckets, rags, plastic sheeting, and
boards are unacceptable temporary covers.
Special concern should be taken to ensure that electrical connections are weatherproof and insect proof as
described in subpart 3 below.
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Subp. 2. Casing connections less than 12 inches above ground. A connection to,
or a fitting on a casing made less than 12 inches above the established ground
surface must be constructed to be watertight, vermin proof, and provide complete
clearance within the internal diameter of the casing. The connection must not be
submerged in water at the time of installation. The connection must be made at or
above the frost line. The connection or fitting must consist of a:
A. threaded connection equivalent to the material and threading standards of
ASTM A53/A53M-04a, ASTM A589-96 (2001), API Standard 5L-04, ASTM
A312/A312M-04b, or ASTM F480-02;
B. welded connection for steel or stainless steel casing where:
(1) the welded fitting must:
(a) be made of forged or machined metal; a cast-iron fitting is not allowed;
(b) be certified for use with pressure rated vessels or piping;
(c) be marked with the design pressure rating and manufacturer;
(d) be made of metal compatible with the casing material;
(e) have a design pressure rating equal to or greater than the casing;
(f) fully integrate branch reinforcement and maintain full casing strength by
providing casing reinforcement, with reinforcement tapering at the sides of the
fitting;
(g) have a contour matching the curvature of the casing; and
(h) be self aligning;
(2) the installer of a welded fitting must:
(a) complete the weld free of slag, inclusions, bubbles, voids or other
imperfections;
(b) use a guide or template for cutting the hole in the casing, or use a
properly sized drilled hole;
(c) install the welded fitting in accordance with the manufacturers
recommendations; and
(d) field weld the fitting by holding the welding rod in a vertical or horizontal
position, or bench-weld the fitting before field installation, with a welding rod as
corrosion-resistant as the casing;
C. solvent welded connection for plastic casing equivalent to the standards of
ASTM F-480-02, or part 4725.2550;
D. bolted sleeve-type coupling meeting ANSI/AWWA Standard C219-01 where:
(1) the bolted sleeve-type coupling must:
(a) have a working pressure rating of at least 150 pounds per square inch;
(b) have an interior coating that complies with ANSI/NSF Standard 61-2003e
if the coupling has an interior coating in contact with water; and
(c) provide for the casing or pipe to extend at least 2.5 inches into the
coupling;
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and
(2) the installer of a bolted sleeve-type coupling must:
(a) install the coupling in accordance with ANSI/AWWA Standard C219-01;
(b) insert the casing or pipe ends at least 2.5 inches into the coupling;
E. pitless adapter or pitless unit meeting the requirements of part 4725.4850,
subpart 1.
A welded, solvent welded, or threaded coupling, adapter, or swaged fitting
meeting the material standards of part 4725.2350, 4725.2550, or 4725.6650, may
be used to connect a casing to a pitless adapter or unit.
Item A references the ASTM and API casing standards.
Item B describes manufactured fittings such as a “Weld-O-Let” or “Thread-O-Let” fitting.
Item C references the plastic casing standards of ASTM F480-02, and Minnesota Rules, part 4725.2550
refers to the plastic well casing specifications and requirements in rule.
Item D refers to specifications of “Dresser”-type couplings. NSF Standard 61-2003e refers to standards
for drinking water system components.
Item E refers to the pitless adapter and pitless unit specifications. The specifications for pitless adapters
and units are located in Minnesota Rules, part 4725.4850. A list of pitless units and adapters that meet the
standard is included in the appendix.
Minnesota Rules, part 4725.2350 refers to the steel casing requirements; Minnesota Rules, part 4725.2550
refers to the plastic casing and coupling requirements; and Minnesota Rules, part 4725.6650 refers to the
flush threaded PVC and stainless steel monitoring well casing standards.
Connections to environmental bore holes, vent/sparge systems, and multiple-use wells and borings
present practical problems because of small-casing diameters and multiple-exit ports. While the rules
allow numerous types of underground connections, it is recommended that a pitless adapter or pitless
unit(s) be used whenever possible. Multiple pitless adapters can be installed by offsetting the discharges
at different heights. If a pitless is not used, a connection to the casing must be made with a
manufactured fitting which meets the requirements listed above. The practice of torch cutting a hole
in the casing, sticking a pipe through the hole, and attempting to weld the connection watertight is not
approved.
The rules require that any underground connection made to the casing of a well or boring must be
watertight. The connection must consist of a threaded connection, welded connection, solvent-welded,
bolted sleeve-type coupling, or pitless adapter or unit. The rule is more restrictive for water-supply wells
(including remedial wells); only a pitless adapter or unit is allowed for the water discharge line.
The watertight requirement applies to any connection including discharge connections, vacuum lines, and
electrical connections.
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Subp. 3. Electrical connections. Electrical wire must enter a casing, cap, cover,
or pump base a minimum of 12 inches above the established ground surface except
for a well or boring completed at-grade in accordance with part 4725.6850.
Electrical wires above the ground surface must be contained within a conduit or
the casing. The electrical wire connection through the casing, cap, cover, or pump
base must be made watertight and vermin proof with a compression fitting, gasket,
or electrical conduit installed in accordance with Minnesota Statutes, section
326.243, or caulk meeting the standards of ANSI/NSF standard 14-2003, or 612003e.
Special emphasis should be placed on electrical wires. Unprotected openings for electrical wires can
allow rodents or insects, such as Asian beetles or earwigs, to enter the well or boring.
STAT AUTH: MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401;
103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05;
144.12; 144.383; 157.04; 157.08; 157.09; 157.13
HIST: 17 SR 2773; 33 SR 211
4725.3200 [Repealed, 17 SR 2773]
4725.3250 PUMPS AND PUMPING EQUIPMENT.
A pump or pump base installed on a well must be constructed so no unprotected
openings exist into the interior of the pump or well casing.
A. A hand pump, hand pump head, stand, or similar device must have a closed
and screened spout, directed downward. The pump must have a concrete slab at
least four inches thick extending horizontally at least one foot in every direction
from the well casing and sloped to divert water away from the casing. A watertight
seal must be provided between the casing and the slab.
The watertight seal may be a gasket or nontoxic caulk such as silicone.
B. A reciprocating pump rod must operate through a stuffing box, packing gland,
or other watertight and vermin proof fitting.
Typical pitcher pumps do not have a stuffing box or packing gland. Pitcher pumps usually do not meet
the requirements of this rule. Rotary-type hand pumps must be sealed to prevent rain, animal feces,
insects, or other foreign materials from entering the well.
C. An oil lubricated vertical turbine pump must not be installed in a well.
An oil-lubricated turbine pump must not be installed in a new well or an existing well.
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An oil-lubricated vertical-turbine pump presently in operation in a well is not required to be replaced with
a nonoil-lubricated pump if the pump is still in operation; however, replacement is recommended. An oillubricated turbine may be removed from an existing well, repaired, and reinstalled in the well as long as
the repair involves replacement of less than 50 percent of the pump. Repair includes replacement of pump
column, bowls, shaft, or motor, but does not include replacement of the oil tube. If the repair involves
more than 50 percent of the pump, the oil-lubricated pump may not be reinstalled.
D. A water lubricated vertical turbine pump must be lubricated with water from
the well or a potable source.
STAT AUTH: MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401;
103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05;
144.12; 144.383; 157.04; 157.08; 157.09; 157.13
HIST: 17 SR 2773; 33 SR 211
4725.3300 [Repealed, 17 SR 2773]
4725.3350 INTERCONNECTIONS AND CROSS CONNECTIONS.
No connection between a well or boring and another well, boring, water supply
system, or contamination source is allowed unless the connection is:
A. protected by an air gap as described in part 4715.2010;
The Minnesota Plumbing Code, part 4715.2010, specifies how the minimum air gap is measured, the
minimum air gap distance based on the outlet size, and the effect of obstructions. An air gap is a physical
separation of an influent pipe (generally a potable water pipe, faucet, or outlet) and a receiving tank,
sewer, or pipe. The minimum air gap or separation is twice the influent pipe diameter. Refer to the
appendix for Minnesota Plumbing Code, part 4715.2010.
B. protected with a backflow prevention device as specified in parts 4715.2020
to 4715.2170;
A backflow prevention device is an assembly of valves, ports, and other flow-regulating devices
intended to prevent a contaminant or potential contaminant from flowing into piping where it is not
intended.
Backflow means the unintended flow of water or other liquids, chemicals, or contaminants into a potable
water system, well, or boring. Backpressure and backsiphonage are two types of backflow. Backflow due
to backpressure occurs when the contaminant is at a higher pressure than the potable water system.
Backflow due to backsiphonage occurs when the potable water line is below atmospheric pressure.
Cross connections are any connections between a potable water supply (including a well, boring, or
groundwater) and a fixture, tank, receptacle, or other equipment through which contaminants may enter
the potable water system. A cross connection may be as simple and obvious as a chemical feed pipe
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connected directly to a potable water pipe, or as complicated and difficult to locate as a single improper
solenoid valve in a large manufacturing plant. Cross connections occur when systems, devices, or
equipment containing potential contaminants are interconnected with an unprotected potable water
system.
Numerous cases of cross connections with resultant illness have been reported in the literature. In
Minnesota within the last few years; atrazine, sewage, antifreeze, solvents, and even propane have
contaminated public water supplies through cross connections.
The Minnesota Plumbing Code, parts 4715.2020 to 4715.2170 outline the requirements for the
protection of potable water against backflow. Backflow prevention assemblies, devices, and methods
include: air gaps, Atmospheric Vacuum Breakers (AVB), Pressure Vacuum Breakers (PVB), hose
connection vacuum breakers (Hose VB), double-check valve with intermediate atmospheric vents
(DCVIAV), RPZ, and double-check valve assemblies (DCVA). Refer to the appendix for Minnesota
Plumbing Code, parts 4715.2020 to 4715.2170.
The backflow prevention assemblies, devices, and methods are listed in the Minnesota Plumbing Code. A
brief description follows:
BACKFLOW PREVENTION DEVICES
AIR GAP. An air gap is a physical separation between a potable water system and potential contaminants.
An example of an air gap is a common sink, where the potable water supply pipe (in this case the faucet)
is above the flood rim (over-flow level) of the basin. An air gap must be at least twice as high as the
inside diameter of the supply pipe. An air gap is simple, inexpensive, and is acceptable for use with direct
or indirect connections and all hazards.
REDUCED PRESSURE ZONE BACKFLOW PREVENTER (RPZ). A RPZ is a manufactured assembly
consisting of two positive-seating check valves located on either side of a pressure differential relief
valve, with shut-off valves on each end. The assembly must have test ports and must be inspected
annually and overhauled every five years. Reduced pressure zone backflow preventers may be used where
back pressure and continuous line pressure exist and where the potential contaminants are hazardous.
DOUBLE CHECK VALVE WITH INTERMEDIATE ATMOSPHERIC VENT (DCVIAV). This device
consists of an atmospheric vent located between two independently operating check valves. The device is
used for low or moderate hazards with small pipe sizes under back pressure and continuous line pressure.
Typical applications are direct connections between a potable water supply and a nontoxic nuisance or
aesthetically unpleasant source such as a swimming pool or food or beverage equipment.
DOUBLE CHECK VALVE ASSEMBLY (DCVA). This assembly has two independent positive-seating
check valves with shut-off valves on each end and four test ports. The assembly is used for low hazard
nuisance or aesthetic concerns.
PRESSURE VACUUM BREAKER (PVB). This assembly consists of an inlet and outlet shut off, one or
more check valves, an air inlet valve, and test ports. It is used where back pressure does not occur but
continuous line pressure does occur. The assembly must be installed 12 inches above the spill line or the
highest outlet downstream of the assembly. Typical applications include process tanks, laundries, and lab
equipment.
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ATMOSPHERIC VACUUM BREAKER (AVB). This device includes an air-inlet valve open to the
atmosphere when the pressure in the line drops to atmospheric. The device is used where no back pressure
exists and cannot be used under continuous pressure. The device must be installed on the discharge side
of the last control valve and must be a minimum of 6 inches above the spill line or the highest elevation of
any line downstream of the device. Applications include lab faucets, cooling towers, and hose bibs.
None of the backflow prevention devices listed above can be buried.
Permissible backflow prevention devices for connection of two wells (except public supply wells), one
meeting the rule standards and the other constructed before 1974 and not meeting the standards, or two
wells in different aquifers, are a double check valve assembly with intermediate atmospheric vent,
reduced pressure zone backflow preventer assembly, or double check valve assembly. It should be noted
that if the two wells are manifolded into a common header, a backflow prevention device is required on
each well. It should also be noted that a double check valve assembly is not just two separate check
valves, it is a manufactured assembly.
The only backflow protection device permitted for interconnection with a public supply is an RPZ, which
requires approval of the administrative authority, yearly testing, and rebuilding every five years.
C. protected with a back flow prevention device as specified in parts 1505.2100
to 1505.2800 if the well is an irrigation well used for chemigation; or
Chemigation is the process of applying agricultural chemicals (fertilizers, pesticides, plant amendments,
or soil amendments) through an irrigation system. MDA Rules, parts 1505.2100 to 1505.2800, became
effective on January 1, 1994. Rules describing the backflow prevention devices are contained in MDA
Rules, part 1505.2300, subpart 3, which is included in the appendix. A summary of the rule follows. The
rule should be consulted for details and additional requirements.
CHEMIGATION RULES SUMMARY
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Chemigation systems must have antipollution devices.
A mainline irrigation system supply must have a reduced pressure zone backflow preventer or two
check valves in series for systems directly connected to a water supply, which must be located in the
irrigation system supply pipeline between the irrigation system water supply pump or source of
irrigation water and the point of injection of the agricultural chemical.
A single mainline check valve may be used for the application of fertilizer.
A reduced pressure zone backflow preventer must be used when the source of irrigation water is
potable water.
If a single irrigation system supply check valve or two irrigation system supply check valves in series
are used, each check valve must be equipped with an inspection port or a similar device and be
immediately preceded in the irrigation system by a vacuum relief valve and automatic low-pressure
drain valve.
An injection line check valve that is resistant to agricultural chemicals must be provided on the
agricultural chemical injection line between the point of agricultural chemical injection into the
irrigation system and the agricultural chemical injection unit, pump, or solution tank.
An interlock, such as electrical, pressure, mechanical, or water motor, must be provided between the
irrigation system or water pump and the agricultural chemical injection unit.
A low-pressure shutdown device must be used.
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D. between wells or borings that meet the construction standards of this chapter,
are used for the same purpose, and have equivalent water quality.
The discharge lines from two wells may be manifolded together without backflow protection if both wells
meet the standards of the rules, are completed in the same aquifer, and if the water quality in the wells is
the same (within normal natural variations). If one or both wells do not meet the construction standards of
this chapter, are used for different purposes or have different water quality, the discharge line from both
wells must be protected with backflow protection.
This part does not apply to a water distribution system after the pressure tank;
however, this part does not exempt water distribution systems otherwise regulated
by chapter 4715.
The DLI licenses plumbers and administers the Minnesota Plumbing Code, Minnesota Rules,
Chapter 4715. The Minnesota Plumbing Code is adopted, amended, and interpreted by the Minnesota
Plumbing Board. A plumbing license and plumbing bond are required statewide to contract for plumbing
in Minnesota. The Minnesota Plumbing Code historically applied only to public facilities and where it or
the Minnesota Building Code was adopted. According to DLI, recent law changes extend the Plumbing
Code statewide. The well and boring rules do not exempt anyone from following (more restrictive)
standards of the Minnesota Plumbing Code.
BACKFLOW PREVENTION FOR FILLING A POND
A well used to fill a pond must be protected from backflow. Acceptable methods include an air gap or a
RPZ. An air gap provides the simplest, cheapest, and safest protection. Where there is no backpressure
(no valves downstream) an AVB may be used as long as it is at least 6 inches above the pond spill line. A
PVB may be used if it is at least 12 inches above the spill line. A spill-proof PVB may be used if it is at
least 6 inches above the pond spill line. The spill proof types are commonly used inside a building since
they don’t normally drip water. A backflow device may not be buried or in a pit.
STAT AUTH: MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401;
103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05;
144.12; 144.383; 157.04; 157.08; 157.09; 157.13
HIST: 17 SR 2773; 18 SR 1222; 33 SR 211
4725.3400 [Repealed, 17 SR 2773]
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