Pub. # 735B93004 Feb 1993
•1
A Guide for Understanding the Atrazine Ground and Surface Water
Risk Reduction Measures
Background
CIBA-GEIGY, the leading manufacturer of atrazine, together with the other basic producers of
the herbicide, initiated and received approvals from the U. S. Environmental Protection Agency
(EPA) for revised labeling of atrazine-^ontaining products. All atrazine-containing products
released for shipment after August 1, 1992 must bear the new labeling except products for
turfgrass, conifer and lawncare uses only. The label changes, designed to protect surface water
quality, provide reduced application rates linked to credibility of the land, mandatory setback
distances, and the deletion of non-selective non-crop uses. These revisions reflect the important
role of pesticide labeling in addressing concerns over die presence of atrazine in surface and
groundwater resources.
The purpose of this document is to provide clarification of label requirements for applicable
atrazine containing products. Strict adherence to pesticide labeling for use of atrazine is the law.
All persons associated in any way with the sale, distribution or use of applicable atrazine-
containing products need to know and understand the revised label requirements. Wnere
questions arise, individuals should refer to the definitions stated in the attached Qs & As. Wnere
restrictions do not apply, individuals should rely on Best Management Practices (BMPs). BMPs
are voluntary or mandatory practices specific to a state, region or area and are designed to
reduce pesticide concentrations in water resources. .
Major Water Quality Protection Elements:
Groundwater Protection
j
On February 20, 1990, the EPA approved label revisions for all atrazine-containing products
(except certain turf, lawncare and conifer use products). These revisions included a reduction
in the maximum allowable label rate for corn and sorghum to no more than 3.0 pounds of active
ingredient per acre, per calendar year.
Since then, the maximum label rate has been reduced to a range of 1.6 to 2.5 pounds active
ingredient per acre per calendar year depending on the amount of plant residue left on the land
and whether the land is classified as "highly credible." The maximum rate per application is
no more than 2.0 pounds of active ingredient (see Surface Water Protection). While not
specifically correlating to overall water quality, rate reduction is viewed as a key element in a
source reduction program. Weed control claims have correspondingly been revised.
A second element in the 1990 label revision was the voluntary classification of atrazine-
containing products (except certain turf, lawncare and conifer use products) as Restricted-Use
Pesticide (RUP) based on groundwater concerns. RUPa may only be applied by or under the
supervision of a certified applicator. Farmers obtain certification as Private Applicators.
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Applicators applying RUP pesticides for purposes other than the production of any agricultural
commodity and/or on a property other than that owned or rented by him or" Kntover S
°f * weU'he^ Protectio« requirement was the third element of the groundwater
Although CIBA-GEIGY is working with EPA to establish an exemption from the setback if the
±f f,miX1lg"IOa,d1^ SltC meetS C6rtain 'P^fi^ons, the currem setback appSo aU wells
unless the product label is amended to reflect the exemption.
calendar year is allowed in certain states as indicated on the label. mgredient *** acre
Summary of Groundwater Protection Elements and
• All atozine-containing products (except for certain turf, lawncare or conifer use products)
are classified as Restricted-Use-Pesticides (RUPs). products)
Protection, atrazine-containing products must not be mixed/loaded or
' *£" ^eUs include abandoned ^to, drainage i^SSthSTcS
water wells and surface water inlets that convey water directiy to groundwater^i T
drainage wells or dry weUs). Tile inlets or intakes that discharge water dkec^to
^h^rl°r ^T^ StreamS °r ^P^^ lakes and reservoirs are
S^HH^C T ^ ?*"* Sink h°1CS Sh°uld * veSetated to "*« run-in
impose additional restnctions under state well-head protection programs.
may
ete
inn? ^PlU"Jbi118 ™T 6Cti0nS •* hooked directly to water S
ng or raising of pesticide containers, mix/load pads, application
Sk fl°W Preventer to Prcvent ****** f
6*1 ** ^ betw?*1 UflUids ^ SUCh conl«fa" or «P*«^ and
operations require constant monitoring to prevent leaks and overflow
All pesticide users must read and follow the label that is on the product being applied.
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• The application of atrazine-containing products through irrigation systems (chemigation) is
prohibited.
Surface Water Protection v
On June 17, 1992, the EPA approved label revisions for all atrazine-containing products (except
certain turfgrass, conifer and lawncare use products). These revisions included a reduction in
the maximum allowable label rate for corn and sorghum to no more than 2.5 pounds active
ingredient per acre per calendar year depending on tillage practices. The maximum rate per
application ranges from 1.6 to 2.0 pounds of active ingredient per acre depending on tillage
practices and whether the land is classified as "highly credible."
The basic intent of the surface water protection label revisions is to reduce the speed and amount
of surface water run-off from treated fields into water bodies. While not specifically noted on
the label, these revisions were implemented to protect surface water that is used for drinking
water.
Surface v-ater bodies now requiring mixing/loading and application setbacks are identified as
perennial and intermittent streams, rivers, natural or impounded lakes, and reservoirs.
Definitions of these surface water bodies, based on those used by the U.S. Geological Survey
(USGS), and clarification of where setbacks apply are provided in the Questions and Answers
section.
In situations where setbacks are not required but there is the potential for atrazine to reach
surface water, voluntary BMP's should be employed.
Surface water runoff control measures consist of two primary elements: 1) reducing application
rates and linking rates to conservation tillage and the percentage of plant residues remaining on
fields to be treated; and 2) mixing/loading and application set-backs from specified water bodies.
Com and sorghum producers who participate in USDA's conservation compliance programs will
already have identified their highly erodible land and be using conservation tillage and plant
residue management. Those not involved in this program should be encouraged to adopt similar
planning and management techniques.
Set-backs are designed to place minimum distances between the actual application area and
points where surface water runoff enters streams, rivers, lakes or reservoirs with the goal of
reducing the amount of pesticide that leaves the treated fields. These measures are intended to
slow down surface water runoff and improve water quality. In situations where the setback
requirements do not apply, follow BMP's suited to the area. Develop a mechanism for
identifying setbacks that applicators can readily follow.
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o
Upfront planning and communication with atrazine users and crop producers is essential to
ensure protection of water resources and Compliance with the label. BMPs for your local area
should be followed in situations where the atrazine label restrictions on mixing/loading and
application (as defined in the attached Qs & As) do not apply. Where there are state/local
requirements regarding atrazine use (including lower maximum rates and/or higher setbacks)
which are different from the label, the more restrictive/protective requirements apply.
Summary of Surface Water Protection Elements and Practices
• All atrazine-containing products (except for certain turfgrass, conifer and lawncare use
' products) are classified as Restricted-Use-Pesticides (RUPs).
Application rates: Restrictions on atrazine use rates for com and sorghum have been tied
to conservation tillage and land erodibility. The maximum application rate is 2.5 Ibs. of
active ingredient per acre per calendar year. Specific rate restrictions are as.follows:
For Applications Prior to Crop Emergence
a) For highly credible soils:
(1) if at least 30% of the field surface is covered with plant residue, the
maximum rate is 2.0 Ibs. of active ingredient per acre.
(2) if less than 30% of soil surface on highly credible land is covered, the
maximum application rate is 1.6 Ibs. of active ingredient per acre.
b) For non-highly erodible soils, the maximum application rate is 2^0 Ibs. of active
ingredient per acre. The maximum application rate is 2.5 Ibs. active ingredient per acre
per calendar year.
For Postemergence Application
If no atrazine was applied prior to corn emergence, apply a maximum of 2.0 Ibs of active
ingredient per acre broadcast. If a postemergence treatment is required following an
earlier herbicide application, the total atrazine applied may not exceed 2.5 Ibs. active
ingredient per acre per calendar year.
Mixing/loading setbacks: For surface water quality protection, atrazine-containing
products may not be mixed or loaded within 50' of a perennial or intermittent stream,
river, natural or.impounded lake or reservoir. See attached Questions and Answers for
clarifications of terms such as "intermittent stream."
For other water bodies where the 50' mixing and loading setback does not apply, BMPs
that minimize the potential for spills or leaks to enter water bodies should be followed.
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Proper use of impervious mix/load pads, backflow preventer, anti-siphon devices, closed
transfer systems, or field mixing/loading away from these water bodies are Best
Management Practices.
Application setbacks: For aerial or ground application, a 66' set-back is required from
points where field surface water runoff enters a perennial or intermittent stream or river.
If land is highly credible, the 66 feet set-back from runoff entry points must be planted
to crop, or seeded with grass or other suitable cover crop.
A 200' application set-back is required around natural or impounded lakes and reservoirs.
Atrazine must not be applied to these set-backs.
Tile inlets or intakes that discharge water directly to groundwater or perennial or
.intermittent streams, rivers, or natural or impounded lakes and reservoirs are subject to
the setbacks.
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UNDERSTANDING ATRAZINE SURFACE WATER RISK
REDUCTION MEASURES
QUESTIONS AND ANSWERS
1. Q- What responsibilities (role) does the agricultural chemical dealer have with
regard to communication of label changes?
A- If the dealer applies compounds containing atrazine to the farmer's land, we
suggest the dealer meet with the fanner prior to the season and develop a plan
on how best to comply with the label restrictions. If the dealer is the primary
source of information for the farmer, the dealer should communicate the label
changes to the farmer. The user/applicator is responsible under federal law
for using the product in a manner consistent with its labeling. A site by site
inspection may be needed to determine where new set-back restrictions apply.
The farmer/applicator can obtain assistance in identifying geological and
hydrological characteristics from USDA's Cooperative Extension Service or
Soil Conservation Service (SCS).
2. Q- What does the dealer need to know about the Safe Drinking Water Act
(SDWA)?
A- The intent of the atrazine label changes approved in 1992 is to reduce the
amount of atrazine entering drinking water sources. Between January 1993
and January 1995, public water utilities are required to begin monitoring for
atrazine, and other substances regulated under the Safe Drinking Water Act
(SDWA). Utilities are required to take a minimum of 4 quarterly finished
water samples. The system is out of compliance if the running annual average
is above the Maximum Contaminant Level (MCL). The MCL for atrazine was
set at 3 micrograms per liter (3 parts per billion) effective July 30, 1992.
Under the SDWA, water utilities detecting atrazine above the MCL are
required to notify the public and take action to reduce levels below the MCL.
Actions could include the implementation of source reduction measures or
upgrading water treatment equipment by the public utility. Best Management
Practices (BMPs) and adherence to the new atrazine label are very positive
steps toward reducing atrazine's presence in drinking water supplies. BMPs
are voluntary or mandatory practices specific to a state, region or area and are
designed to reduce pesticide concentrations in water resources.
If the dealer's location or if the grower's farmland is in a recharge or wellhead
protection area or within a setback for a public drinking water supply,
additional environmental safeguards may need to be initiated-to manage
pesticide use. The water utility, and/or state water protection or state lead
pesticide agency may direct safeguards in addition to those required by the
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atrazine label changes.
^3™ AA/TlAr T
"uere can I obtain a list
.:
1 a wheat/fallow/wheat
A » '
during
5. Q.
A-
6- Q- Does
es or terrace drains into a tile? * 3PP y to standPipes, drainage field
A- Yes, if the tile* discharge to the following:
Wells
a « -*« •»
discharge point is a least 200- ft™, ,, "^cation »«bact unless the
„ n
7- Q- What is a sinkhole?
A- i
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provide a direct pathway for surface water to move into the subsurface.
They occur singly, or in groups in close proximity to one another.
Sinkholes range from a few feet to hundreds of feet in depth. Not all
topographic depressions are sinkholes. Consult with the local extension
service or geologic survey for more detailed information about your area.
The 50' mixing/loading/application setback applies to all sinkholes.
8. Q- What is the definition of an intermittent stream?
A- At this time, the EPA accepts the following USGS definition of a stream and
intermittent stream: "A stream is a body of water flowing in a natural surface
channel. Streams which flow only during wet periods are termed intermittent
streams." EPA also considers ephemeral streams (streams or portion of a
stream which flows only in direct response to precipitation and whose channel
; is above the water table) to be included in the above definition. Although
USGS and USDA/SCS maps are available for reference, if an intermittent
stream fits the USGS definition adopted by EPA or is commonly known as an
intermittent stream, the 50' mixing/loading setback applies and the 66'
application setback from the points where surface water runoff enters the
stream applies - even if the intermittent stream does not appear on a USGS or
SCS map. A site by site inspection should be undertaken to determine where
the above mentioned setbacks apply.
9. Q- Does the 66' application setback apply to ditches?
A- All ditches are exempt from setbacks except where the ditch falls within
another specified setback required by the label changes. However, Best
Management Practices (BMPs), and SCS guidelines for constructing and
maintaining agricultural drainage ditches, should be followed. Grass
waterways-are also exempt from setbacks (except where they fall within a
specified setback required by the label changes). However, atrazine may not
be applied directly to the grass waterway.
10. Q- What is a farm pond versus a natural or impounded lake, and what
setbacks apply to each?
A- A farm pond is defined as a water impoundment made by constructing a dam
or an embankment or by excavating a pit or dugout. Farm ponds are exempt
from the setback requirements if they meet all of the following criteria: 1)
the farm pond is located wholly on the farmer's property, 2) it is not used for
human drinking water, 3) its discharge is not conveyed directly to a perennial
or intermittent stream or river through a clearly traceable, concentrated water
course.
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11. Q-
A- _ iw
mixing anH i/->o^:_ number of interim m
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training, numerous magazine articles, public announcements, and other
educational matenalynade available to the trade, extension service, state lead
agencies, and commodity groups. (Include 800 number?)
14. Q- How and when will the new label appear on products?
A" IS^S^SS*0** ^Uir"8 ** label Chan8«) released for shipment after
August 1, 1992 must bear the new labeling. Dealers will receive ~
a
15. Q- Is pre-emerge application preferred over post-emerge?
A- The ultimate goal of the refined definition of application timing combined with
plant residue requirements is to keep atrazine out of ground and surface water
and on the field. Since the timing of application may depend on local weather
conditions and the Best Management Practices recommended for your area me
farmer should contact the USDA State Cooperative Extension Service «
appropriate State Lead Pesticide Agency for recommended BMPs and
information regarding timing of application.
16. Q- Does the 50' setback apply to dealer wells?
A- Yes. Although, CIBA-GEIGY has requested an exemption from the setback if
the dealer s muung-loading site meets certain specifications, the current
setback applies to all wells unless the exemption is granted and the product
label is amended to reflect the exemption.
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