Subpart
1.
Application of agricultural chemicals through irrigation
systems.
A. A pesticide may be applied
through an irrigation system only if the pesticide is labeled for the method
and device specified for application, the crop, and application site.
B. Fertilizers may be applied through
irrigation systems.
Subp.
2.
Setbacks and safeguarding.
A. Agricultural chemical storage areas and
supply tanks, the end of the discharge hose for check valve drain lines, and
agricultural chemical mixing and loading areas must not be located closer to a
water supply well than the distance specified in chapter 4725. If not specified
in chapter 4725, the minimum setback distance for agricultural chemical storage
areas and supply tanks, the end of the discharge hose for check valve drain
lines, and mixing and loading areas from the water supply must be the same as
the minimum setback distance specified in chapter 4725 for agricultural
chemical supply tanks and agricultural chemical mixing and loading areas used
for chemigation.
B. An agricultural
chemical supply tank must be safeguarded if the tank storage meets at least two
of the following conditions:
(1) the supply
tank has a rated capacity of more than 1,500 United States gallons;
(2) the supply tank is located within 100
feet of a water supply; or
(3) the
supply tank is located at a chemigation site for more than 30 consecutive
days.
C. If required,
agricultural chemical supply tanks must be confined to a safeguard that is
adequate in the event of a release to prevent movement of the agricultural
chemical to the water supply.
The safeguard must consist of a wall and liner or
prefabricated basin as specified in item E.
D. The capacity of the safeguard for an
agricultural chemical supply tank must be at least equal to the sum of all of
the following:
(1) the volume of the largest
agricultural chemical supply tank or other container within the
safeguard;
(2) 25 percent of the
capacity of the largest agricultural chemical supply tank or other container
within the safeguard for an unroofed safeguard, or ten percent of the capacity
of the largest agricultural chemical supply tank or other container within the
safeguard covered by a roof; and
(3) the total volume of released liquid that
would be displaced by the portions of all other containers with the safeguard
to the height of the safeguard wall and all other fixtures and materials
located within the safeguard.
E. The walls and base of a safeguard may be
made of ferrous metal, reinforced concrete, solid reinforced masonry, synthetic
lined earth, or prefabricated ferrous metal or synthetic materials. The
safeguard must be designed according to standard engineering practices to be
leakproof and to withstand a full hydrostatic head of released liquid to the
height of the safeguard.
(1) Masonry walls
must be reinforced, capped with concrete, and parged on the interior. The joint
between any masonry wall and any floor or liner must use internal waterstops or
similar materials to make the joint leakproof. Control joints protected with
waterstops or similar materials must be used for the base. The interior base
and walls must be coated with a material resistant to agricultural chemicals.
Cracks and seams must be sealed.
(2) The joints between a reinforced concrete
wall and any floor or liner must use internal waterstops or similar materials
to make the joint leakproof. Control joints protected with waterstops or
similar materials must be used for the base. The interior base and walls must
be coated with a material resistant to agricultural chemicals. Cracks and seams
must be sealed.
(3) Synthetic
liners must have a minimum thickness of 30 mils (0.8 millimeters), be
chemically compatible with the materials being stored within the safeguard,
photo resistant, and puncture resistant. The earthen base of a synthetic liner
must be free of large rocks, angular stones, sticks, or other materials that
may puncture the liner.
(4) A
prefabricated safeguard must be composed of rigid walls and a base of ferrous
metal or synthetic materials that are resistant to corrosion, puncture, or
cracking. Materials used for the safeguard must be chemically compatible with
the materials being stored within the safeguard. Synthetic materials must be
photo- and puncture-resistant.
(5)
The base and walls of a safeguard may not contain a drain or similar
opening.
Subp.
3.
Antipollution devices.
Chemigation systems must be filed with antipollution devices
as detailed in this subpart. The devices must be designed and built of
materials suitable for those purposes, including agricultural chemical
compatibility, and must be kept functional during chemigation. Antipollution
devices may be installed as portable devices for use on other permitted
chemigation systems, except that portable devices are not allowed for use on
systems connected to the public water supply.
A. A mainline irrigation system supply
reduced pressure zone backflow preventer or two check valves in a series must
be provided for systems directly connected to a water supply, and 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.
The following additional conditions apply:
(1) Mainline check valves:
(a) a single mainline check valve may be used
for the application of fertilizer;
(b) mainline check valve backflow prevention
devices must meet the design and equipment standards in item B;
(c) mainline check valve backflow prevention
devices must be tested and certified by an independent testing laboratory to
meet the performance standards in item B; and
(d) mainline check valves must be stamped,
tagged, or otherwise marked to indicate working pressure, flow rate, and
direction, and date, month, and year of manufacture.
(2) Reduced pressure zone backflow
preventers:
(a) a reduced pressure zone
backflow preventer must be used when the source of irrigation water is potable
water; and
(b) a reduced pressure
zone backflow preventer must be approved under chapter 4714, and applicants
must install and maintain a reduced pressure zone backflow preventer under
chapter 4714.
Mainline check valves approved by the commissioner under
repealed parts
1505.2000 to
1505.2080 may continue to be used
after October 12, 1992, if the mainline check valves comply with item B and the
department has been notifled of any changes in design or materials.
B. If a
single irrigation system supply check valve or two irrigation system supply
check valves in a series are used, each check valve must be equipped with an
inspection port or similar device and be immediately preceded in the irrigation
system by a vacuum relief valve and automatic low pressure drain valve.
The inspection port must be installed on the horizontal
irrigation pipeline on the supply side of each check valve in a manner that the
inlet to the automatic low pressure drain can be easily observed during
irrigation system shutdown.
The vacuum relief valve must be installed on the top of the
horizontal irrigation pipeline on the supply side of the check valve. The valve
must have an orifice size of at least a three-quarter inch diameter for a
four-inch pipe; a one inch diameter for a five-inch to eight-inch pipe; and a
two inch diameter for a ten-inch or 12-inch pipe.
The automatic low pressure drain must be provided on the
bottom of the horizontal irrigation pipeline on the supply side of the check
valve. The device must have an internal and external orifice size of at least a
three-quarter inch diameter. If two check valves in a series are required to be
used, the check valve located in line nearest to the pivot or irrigation system
must meet one of the following specifications:
(1) the check valve must use a spring-loaded,
automatic, low pressure drain or an automatic low pressure drain with similar
operating characteristics; or
(2)
the check valve must use an automatic low pressure drain that will drain the
supply side of the body of the check valve within three minutes of system
shutdown.
The drain may not extend beyond the inside surface of the
bottom of the irrigation pipeline or conduit and must be at least two inches
above grade. The device must be positioned, or the location of the grade
adjusted, so that liquid will discharge away from a water supply when draining
occurs.
An irrigation system supply check valve must be of heavy duty
construction with all materials, including internal parts, resistant to
corrosion or protected to resist corrosion. It must be rated a minimum of 150
pounds per square inch working pressure and be quick closing by spring action
and tight sealing so that no leakage occurs at joints or the valve seat when
subjected to an internal hydrostatic pressure test of at least 300 pounds per
square inch for one minute. There must be no leakage at joints or the valve
seat when the check valve is subjected to an internal hydrostatic pressure
equivalent to the head of a column of water five feet high, retained within the
downstream portion of the valve body for 16 hours.
Irrigation system supply check valves, when installed, must
be level except that a deviation of not more than ten degrees from the
horizontal is permitted.
C. 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, and be functional to prevent the flow of liquid from the
irrigation line to the agricultural chemical injection device and the flow of
liquid or material from the agricultural chemical supply tank to the irrigation
line.
D. 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.
If interruption of the irrigation water flow occurs, the interlock must, at a
minimum, cause the shutdown of the agricultural chemical injection
unit.
E. A low pressure shutdown
device must be used with the irrigation system that will shut down the
irrigation system if the water pressure decreases to the point when an incident
may occur.
Subp. 4.
Purging system.
The irrigation system must be operated as necessary on each
and every occasion after an agricultural chemical injection is terminated to
allow for a complete purging of the agricultural chemical from the
system.
Subp. 5.
Posting of sites.
Sites being treated with pesticides through chemigation
systems must be posted with signs during pesticide treatment. The posting of
signs is governed by items A to D.
A.
Signs must be in compliance with subitems (1) to (3).
(1) Signs must be at least eight and one-half
inches by 11 inches, highly visible, with contrasting colors for letters and
background.
(2) Letters must be at
least three-eighths of an inch tall.
(3) Signs must contain at least:
(a) the signal word from the pesticide
label;
(b) the name of the
pesticide;
(c) the date of
treatment; and
(d) the reentry date
as described on the pesticide label.
B. Signs must be conspicuously placed at
usual points of entry for all sites and at property corners for nongreenhouse
sites that are immediately adjacent to public transportation routes or other
public or private nonagricultural property, except that signs must be placed no
greater than 100 feet apart for a field chemigation site that is located
immediately adjacent to a public area such as a park, school, or residential
area.
C. Signs must be removed
after the reentry date expires unless signs are of a more permanent nature,
such as laminated signs, in which case information must be updated as
necessary.
D. If more restrictive
instructions for posting exist on the label of the pesticide being used in
chemigation, the label instructions must be totally followed.
