ADEQ: Arizona Department of Environmental Quality, Arizona's Official Web Site
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Water Quality Division: Permitting: Pesticide Groundwater Quality Protection

Arizona’s Pesticide Groundwater Quality Program

The Arizona Pesticide Groundwater Quality Protection Program was established to prevent or eliminate the pollution of aquifers of the state from routine use of agricultural pesticides. The program is responsible for evaluating mobility and persistence data submitted in support of new pesticide product registration and identifying which active ingredients (AIs) have the potential of polluting Arizona groundwater. The program generates the Groundwater Protection List (GWPL), enforces any data gap violations and conducts regular groundwater monitoring. An annual report on pesticide usage is presented to the state legislature and is present on the website.

Pursuant to the Environmental Quality Act of 1986, ADEQ requires applicants intending to register new agricultural-use pesticides with the Arizona Department of Agriculture to submit groundwater protection data for review and approval. After completing a substantive technical review, ADEQ determines if the products AI poses a threat to groundwater quality.

The term “agricultural use” is defined to include all applications of pesticides for use directly on a crop.

The following areas (but not limited too) are defined as agricultural use area:

  • Greenhouses (commercial or research)
  • Cropland
  • Food and fiber production
  • Forests
  • Irrigation ditches
  • Rangeland
  • Ground applied seed protection
  • Soil fumigation
  • Tree farms
  • Sod farms
  • Aquatics

The term “crop” is defined as any plant, animal, plant product or animal product produced for commercial or research purposes.

The term “pest” is defined as any weed, insect, vertebrate pest, nematode, fungus, virus, bacteria or other pathogenic organism or any other form of terrestrial or aquatic plant or animal life.

The term “pesticide” is defined as any substance or mixture of substances intended for either, preventing, destroying, repelling or mitigating any pest or used as a plant regulator, defoliant or desiccant.

To help expedite review of a new product with a new active ingredient, registrants should complete the Data Summary Form and additional information described in New Pesticide Product with a New Active Ingredient.

To help expedite new agricultural use pesticide product registration with the Arizona Department of Agriculture, registrants should complete the Arizona Department of Agriculture New Agricultural Use Pesticide Evaluation Form, additional information described in the following standard procedure and process flow chart. The attached Active Ingredient spreadsheet that includes all registered active ingredients and the companies who registered them by ADEQ should be reviewed prior to submitting your application to the Arizona Department of Agriculture.

The submittal of mobility and persistence data, unless the ADEQ Director grants a waiver, applies to all U.S. EPA registered agricultural use pesticides, including products with a new AI or those containing currently approved AI, also known as “me too” products or “generics”. Supplemental registrants (distributors) and formulators are only exempt if they rely on data from the primary registrant and provide documentation of a business arrangement or a letter of authorization (LOA) to use data available to ADEQ.

All pesticide product data submitted to ADEQ, including the product chemistry and environmental fate studies of the corresponding AI(s) must be consistent with U.S. EPA guidelines for these studies and comply with Arizona environmental (soil) requirements. ADEQ will evaluate the data submitted by applicants, determine their adequacy, validity and completeness and will inform the intended registrant of the outcome within the specific time frames for administrative completeness and substantive technical review. All data submitted must be complete, presented in English and summarized on the Data Summary Form. The following are the guidelines for data submittal for the various categories of prospective registrants.


New Product Categories

To facilitate the submittal of appropriate data and/or documents for ADEQ evaluation, pesticide products are classified into three main categories:

  • New Pesticide Product with a New Active Ingredient
  • New Pesticide Product with a Previously Approved Active Ingredient
  • New Pesticide Product eligible for a Waiver

New Pesticide Product with a New Active Ingredient

There are two approaches available to registrants in submitting environmental fate data for products with new active ingredients as defined in Arizona Revised Statutes (A.R.S.) §§49-302, 49-303(3) and Arizona Administrative Code (A.A.C) R18-6-102.

  • Standard Evaluation Process – This approach evaluates the potential of a pesticide’s AI(s) to pollute groundwater by requiring numeric data on a number of factors affecting the mobility and persistence of an AI and/or its degradation products. These values are compared to standards or criteria established by ADEQ called “Specific Numeric Values” (SNVs). The numeric values obtained from submitted studies must have been performed using testing methods described in the U.S. EPA’s Pesticide Assessment Guidelines. Pesticides that exceed these criteria outlined in Table 1 in both mobility and persistence criteria will be placed on the GWPL (A.A.C. R18-6-103(1).
  • Alternate Evaluation Process – In accordance with A.R.S. § 49-302(E) and A.A.C. R18-6-103(2), a prospective registrant may submit alternate information to satisfy one or more of the data requirements. The alternate information will accurately describe the relevant data required for each new pesticide active ingredient under similar environmental and use conditions as Arizona. Supporting documents acceptable to ADEQ include data summaries or product evaluation reports from other states in the southwest United States (such as California) or U.S. EPA product data reviews. Additional information should include a detailed written assessment of the environmental fate of the active ingredient with respect to environmental conditions similar to Arizona’s, including consideration of factors such as proposed pattern of use, applicable cultural practices, pertinent geologic and pertinent meteorologic conditions. A list of the required documents and studies are listed in Table 2.

ADEQ rules (A.A.C. R18-6-102(C)(2)) allow an applicant to submit any other relevant scientific data and summaries where the additional data may enhance the ability of ADEQ to determine whether the pesticide’s active ingredient has the potential to pollute groundwater. However, submittal of this information, evaluations and conclusions from other states or agencies, especially those not in the southwest, may not add to the completeness determination.

All supporting documents and/or studies must be submitted electronically on a CD or DVD according to the following procedure:

  • Provide an index for each file submitted electronically
  • Save as the file name the name of each study (i.e., Mobility Studies.pdf)

New Pesticide Product Containing a Previously Approved Active Ingredient

A prospective applicant for registration of a new product containing an active ingredient previously approved by ADEQ (“me too” products) should indicate if the company is the manufacturer, formulator, supplementary registrant or distributor and provide information of the source of its technical grade product. Groundwater data requirements will depend on which of the following sub-categories the prospective registrant belongs.

  • Manufacturer – Technical product is manufactured directly by the registrant
  • Formulator – Technical product is purchased from an existing registrant and is reformulated
  • Supplemental Registrant or Distributor – Existing product is re-labeled and distributed under a name and address other than that of the primary registrant whose product may or may not have been registered in Arizona
  • Manufacturer – If the prospective registrant is a manufacturer of a new product containing an active ingredient previously evaluated and approved by ADEQ, the applicant shall comply with one of the following data submittal requirements:
    • Follow the same procedure as a New Pesticide Product with a New Active Ingredient and register the active ingredient in the manufacturer’s name
    • If the applicant’s product is already registered in California, the applicant may provide the following documents in support of the application:
      • Cover Letter
      • U.S. EPA stamped/accepted label
      • California Department of Pesticide Regulation (DPR) letter of registration and Product Evaluation Report
      • U.S. EPA letter indicating substantial similarity and U.S. EPA Statement of Formula
  • Formulator – If the applicant is a formulator and wants to rely on the information generated by another company to meet the data requirements, such an applicant shall provide, along with the U.S. EPA approved label, a letter of authorization (LOA) or evidence of a business arrangement with the owner of the data. In the event the owner will not support the applicant’s registration, the prospective registrant will be responsible for providing the information necessary to register the product and would follow the same procedure as a New Pesticide Product with a New Active Ingredient.
  • Supplemental Registrant – If the applicant is a supplemental registrant of a product whose active ingredient has not been previously approved by ADEQ, the applicant must comply with the data requirements of a New Pesticide Product with a New Active Ingredient. If the primary product with the same active ingredient(s) was previously registered in Arizona, the applicant must provide along with the U.S. EPA approved label, a LOA or evidence of a business arrangement with the primary registrant of the product’s active ingredient(s). In the event that the primary registrant will not support the registration, the supplementary registrant will be responsible for providing the information necessary to register the product and would follow the same procedure as a New Pesticide Product with a New Active Ingredient.

New Pesticide Product Seeking a Waiver

In accordance with A.R.S. § 49-302(D) and A.A.C. R18-6-102(A)(3), ADEQ may waive groundwater data submittal requirements if the product’s active ingredient by it nature or mode of occurrence will not pose a risk to groundwater quality. The following products will be considered for a Waiver request:

  • Biopesticides as defined by the U.S. EPA to include naturally occurring substances that control pest (biochemical pesticides), microorganisms that control pests (microbial pesticides) and pesticide substances produced by plants containing added genetic material (plant-incorporated protectants) or PIPs
  • Products granted a U.S. EPA waiver of Tier II environmental fate data requirements
  • Other products that are made of naturally occurring geological materials (“geopesticides”) or mineral matter that are common or ubiquitous in nature (e.g., diatomaceous earth, kaolin, sulfur, copper sulfate or iron phosphate) and pose no perceptible risk to groundwater quality

Applicants for a Waiver shall submit the following documents in support of the product waiver request:

  • Cover letter
  • Product information (including, but not limited to, Material Safety Data Sheets (MSDS))
  • U.S. EPA approved/stamped label
  • U.S. EPA waiver approval or California DPR product review report (if applicable)

Application Time Frames

The data review/approval for new pesticide active ingredients under A.R.S. § 49-302(F) and A.A.C. R18-6-102(B) of the Pesticide Groundwater Quality Protection Program is subject to the requirements of the licensing time frame statute under A.R.S. § 41-1072 through 41-1079 and the licensing time frame rule A.A.C R18-1-501 through R18-1-525 Table 7. The Administrative Completeness review time frame is 62 days and the Substantive Review time frame is 124 days. All submissions in response to this Notice must include the required documents and must be addressed to:

David Haag, Pesticide Program Coordinator
Arizona Department of Environmental Quality
Water Quality Division
Groundwater Section
1110 West Washington Street, 5415B-3
Phoenix, Arizona 85007

Arizona Soil Requirements for Groundwater Protection Data

All data submitted to ADEQ involving soil testing are required to meet the Arizona agricultural soil requirements (A.R.S. § 49-302(C)) with respect to soil pH and soil organic content. Soils from the United States, particularly from the southwest are preferred.

  1. The pH of soils used for soil adsorption coefficient, soil photolysis, aerobic and anaerobic soil metabolism and field dissipation studies must be between 6.5 and 8.5 which accurately reflect the pH range found in Arizona agricultural soils.
  2. The organic carbon content of soils used for soil adsorption coefficient, soil photolysis, aerobic and anaerobic soil metabolism and field dissipation studies must be less than or equal to 2.6 percent. This range most accurately reflects the organic carbon content of Arizona agricultural soils.
  3. Three different Arizona-like soils are required for the soil adsorption coefficient study and two different Arizona-like soils are required for the field dissipation study.
  4. The same soil must be used for both aerobic and anaerobic soil metabolism studies.
  5. Field dissipation studies must be conducted in the field and laboratory studies submitted for this requirement will not be accepted. Likewise, field studies submitted in support of laboratory studies will not be accepted.
  6. Aquatic field dissipation studies may not be required for those pesticides intended for aquatic uses if a terrestrial field dissipation study has been submitted and accepted.
  7. Tank mix field dissipation studies are not required for those compounds included in a tank mix if separate terrestrial field dissipation studies have been submitted and accepted for each component active ingredient of the tank mix.
  8. Forestry field dissipation studies need not include soils which meet pH and percent organic carbon criteria of Arizona agricultural soils.
  9. For more information regarding the criteria of the groundwater protection data, please refer to Subdivision D and N of the U.S. EPA’s Pesticide Assessment Guidelines.

Groundwater Protection List

According to A.R.S. § 49-305, ADEQ is required to establish a Groundwater Protection List (GWPL) containing active ingredients that have the potential to pollute groundwater. ADEQ conducts groundwater monitoring program of the GWPL active ingredients to determine whether they have migrated to groundwater.

Each year, the GWPL is revised and presented for public comment in the Arizona Administrative Register (A.A.R.) published by the Arizona Secretary of State for a 30-day public comment period (A.A.C. R18-6-301(A)(1) and (2)). The annual revised list consists of additions and deletions from the previous list, based on new registrations and deletions of active ingredients. Active ingredients may be removed from the list for several reasons outlined in A.A.C. R18-6-301. The final GWPL after public comment is published each year in the Annual Pesticide Report and becomes effective on December 1 of the publication year. The current list of active ingredients on the GWPL is shown in Table 3.

The GWPL enable ADEQ to focus its statewide groundwater monitoring activities on the active ingredients requiring monitoring and testing. If any of these active ingredients is detected in groundwater as a result of agricultural activities, ADEQ may, depending on the level at which they were detected, require registrants to modify their application use patterns or may recommend to the Arizona Department of Agriculture to cancel the registration to prevent further contamination.

Both statute (A.R.S. § 49-305(A)) and rule (A.A.C. R18-6-303) require ADEQ to regulate the use of those active ingredients on the GWPL intended for application to or injection into the soil by groundwater application equipment or chemigation or if the application site will be flood or furrow irrigated within 72 hours of application of the pesticide based on label recommendations.

The rule requires that any person who soil applies an agricultural use pesticide on the GWPL must implement Best Management Practices to reduce or prevent the pollution of groundwater. This requirement applies equally to a person who hires another individual to soil apply an agricultural use pesticides on the GWPL such as an aerial applicator, pest control advisor or farm worker. The following is a link to a 2009 ADEQ Arizona Department of Agriculture document "Managing Pesticides to Protect Groundwater Quality."

Click here to file a complaint.

Click here to contact ADEQ's Pesticide Program.

Click here to contact ADEQ's Surface Water Pesticide Permit program.

Arizona Department of Agriculture Contact Person for General Information on Pesticides:
Jack Peterson, Associate Director
Arizona Department of Agriculture
Environmental Services Division
1688 West Adams Street
Phoenix, Arizona 85007

Related Statutes and Rule