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


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                                                           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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