United States Environmental Protection Agency Public Notice of: Draft National Pollutant Discharge Elimination System (NPDES) Pesticide General Permit (PGP) for Point Source Discharges to Waters of the United States from the Application of Pesticides

United States Environmental Protection Agency
Public Notice of:

Draft National Pollutant Discharge Elimination System (NPDES)
Pesticide General Permit (PGP) for Point Source Discharges to Waters
of the United States from the Application of Pesticides

Fact Sheet

A NOTE TO REVIEWERS AND COMMENTERS:

EPA proposes the text in this draft Fact Sheet as part of the Proposed 2026 PGP. Where the Fact
Sheet reflects permit provisions that are unchanged from the 2021 PGP, EPA proposes the draft
Fact Sheet text in present tense rather than conditional tense (e.g., "This Part requires" versus "This
Part would require", or "The Operator must" versus "The Operator would be required to"). Where
EPA proposes specific changes to the permit from the 2021 PGP, the Fact Sheet text reflects that
(e.g., "EPA proposes that..."). With the inclusion of this note, reviewers and commenters should
read and interpret all text as proposed and not final. EPA is proposing the Fact Sheet in this format
so readers can see any proposed language as it might be written in the final permit and to improve
editing efficiency during the permit finalization process.

Agency: United States Environmental Protection Agency
Action: Notice of NPDES General Permit

PRE-PUBLICATION NOTICE. All 10 U.S. Environmental Protection Agency Regions signed the following document on
November 8, 2023, and EPA is submitting it for publication in the Federal Register (FR). EPA is providing this document solely
for the convenience of interested parties. This document is not disseminated for purposes of EPA's Information Quality
Guidelines and does not represent an Agency determination or policy. While we have taken steps to ensure the accuracy of this
Internet version of the rule, it is not the official version of the final rule for purposes of compliance or effectiveness. Please refer
to the official version in a forthcoming FR publication, which will appear on the Government Printing Office's govinfo website
(https://www.govinfo.gov/app/collection/fr) and on Regulations.gov (https://www.regulations.gov) in Docket No. EPA-HQ-OW-
2023-0268. Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until
published in the Federal Register.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

CONTENTS

I.	Background	1

1.	Clean Water Act	2

2.	NPDES Permits	3

3.	History of Pesticide Application Regulation	4

4.	Court Decisions Leading to the CWA Regulation Concerning Pesticide
Applications	4

II.	Structure of the PGP	5

1.	General	5

2.	Conformance to Court Decisions	6

3.	Sharing of Responsibilities	9

III.	Summary of Draft 2026 PGP Conditions	10

1.	Coverage Under the Draft 2026 PGP	10

1.1	Eligibility	10

1.2	Authorization to Discharge Pollutants Under this Permit	21

1.3	Alternative Permits	28

1.4	Severability	30

1.5	Other Federal and State Laws	30

1.6	Federally Listed Endangered and Threatened Species and Designated Critical
Habitat	30

2.	Effluent Limitations	31

2.1	Applicators' Responsibilities	40

2.2	Decision-makers' Responsibilities	41

3.	Water Quality-Based Effluent Limitations	66

4.	Site Monitoring	68

4.1	Visual Monitoring Requirements for Pesticide Applicators	70

4.2	Visual Monitoring Requirements for all Operators	71

4.3	Documentation of Visual Monitoring	72

4.4	Additional Monitoring	72

5.	Pesticide Discharge Management Plan (PDMP)	73

5.1	Contents of the PDMP	74

5.2	Pesticide Discharge Management Plan Modifications	77

5.3	Pesticide Discharge Management Plan Availability	78

6.	Corrective Action	78

6.1	Situations Requiring Revision of Pest Management Measures	78

6.2	Corrective Action Deadlines	79

6.3	Effect of Corrective Action	79

6.4	Adverse Incident Documentation and Reporting	80

6.5	Reportable Spills and Leaks	82

6.6	Documentation for Other Corrective Action	83

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

the Federal Register.

7. Recordkeeping and Annual Reporting 83

7.1 Records to be Kept by all Operators (all Decision-makers and all Applicators) 83

7.2 Records to be Kept by all For-Hire Applicators 84

7.3 Records to be Kept by Small Entities, Submitting an NOI 84

7.4 Records to be Kept by Large Entities, Submitting an NOI 85

7.5 Retention of Records 86

7.6 Annual Reports 86

7.7 Annual Reporting for Any Decision-maker with Discharges of Pollutants to
Waters of the United States Containing NMFS Listed Resources of Concern, as
Defined in Appendix A of the Permit, and Who is a Small Entity 88

7.8 Electronic Reporting Requirement 89

8. EPA Contact and Mailing Addresses 89

9. Permit Conditions Applicable to Specific States, Indian Country, or Territories 90

10. Permit Appendices 90

A. Definitions and Acronyms 90

B. Standard Permit Conditions 90

C. Areas Covered 91

D. Noti ce of Intent F orm 91

E. Notice of Termination Form 92

F. Pesticide Discharge Evaluation Worksheet 92

G. Annual Report Template 92

H. Adverse Incident Report Template 92

I. Endangered Species Procedures 93

IV. Fact Sheet Appendices 94

APPENDIX A. List of Pesticides and Degradates Which Exceeded Aquatic-life

Benchmarks in the USGS 2021 Study 94

APPENDIX B. Regulatory Status and Chemical-specific Mitigation Measures for
Pesticide Active Ingredients with at Least One Aquatic Life Benchmark

Exceedances in the USGS 2021 Study 96

APPENDIX C. 303(d) Impairment Example - CA Central Valley Regional 303(d)

Impairment List of Pesticides 99

APPENDIX D. Cost Impacts and Number of Entities Covered 103

APPENDIX E. Environmental Justice Considerations 106

APPENDIX F. EPA's Consideration of the Regulatory Criteria in §122.28(b)(2)(v) 108

APPENDIX G. EPA's Rationale for Requiring NOIs 110

APPENDIX H. Recommended Pesticide Use Pattern Reference 114

APPENDIX I. Factors to Meet Applicable Water Quality Standards 118

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

L Background

The United States Environmental Protection Agency (EPA) is proposing to reissue the
National Pollutant Discharge Elimination System (NPDES) pesticide general permit (draft 2026
PGP) which authorizes the point source discharges of biological pesticides, and chemical
pesticides that leave a residue, to waters of the United States. Once finalized, the draft 2026 PGP
will replace EPA's 2021 PGP on October 31, 2026 and will be available to Operators in
geographic areas where EPA is the NPDES permitting authority. This fact sheet describes the
draft 2026 PGP which is being proposed. Appendix C of the draft 2026 PGP contains a list of
areas eligible for coverage. Supporting information and materials for the draft 2026 PGP are
included in Docket ID No. EPA-HQ-OW-2023-0268 available at https://www.regulations.gov/.

After EPA issued the 2021 PGP in September 2021, a petition for review of the permit was
filed. The petition was filed by the Center for Biological Diversity (CBD) in the U.S. Court of
Appeals for the Ninth Circuit, challenging EPA's permit issuance under the Clean Water Act
(CWA), and EPA and the U.S. Fish and Wildlife Service (FWS) actions with respect to the
permit under the Endangered Species Act (ESA). After CBD filed the petition, EPA, FWS, and
CBD entered into settlement discussions. A settlement agreement resulted from these
discussions, which the parties entered into on July 25, 2023 (Settlement Agreement). The
Settlement Agreement does not affect the provisions in the 2021 PGP, but several terms concern
the draft 2026 PGP. Information on the Settlement Agreement is available in Docket ID EPA-
HQ-OGC-2023-0247-0002.

Largely, conditions and requirements in the draft 2026 PGP remain unchanged from the
2011 PGP, 2016 PGP, and 2021 PGP. However, EPA has proposed certain changes in an effort
to pursue continuous improvement to water quality protection and to meet the terms of the
Settlement Agreement. EPA seeks comment on these proposed changes. The draft 2026 PGP
includes the following proposed changes from the 2021 PGP which are summarized below and
discussed in Part III, Summary of the Draft 2026 PGP Conditions, of this fact sheet:

Clarifies the visual monitoring requirements and strengthens compliance:

• Added Part 4.3, Documentation of Visual Monitoring, to reiterate the requirement to record
visual monitoring as required under Parts 7.2, 7.3, and 7.4;

• Added Part 4.4, Additional Monitoring, to emphasize additional monitoring could be
required by EPA to ensure compliance with PGP;

• Requires Decision-makers to submit Pesticide Discharge Management Plan (PDMP) with
NOI submission (Part 5);

• Updated PDMP contents to include visual monitoring procedures (Part 5);

• Added that if visual monitoring was performed, the record must include the date, time, and
location (Part 7);

• Required Decision-makers to submit visual monitoring records with an Annual Report (Part

7).

Changes needed to meet existing regulations as part of the routine permit reissuance process:

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

• Added a field for NAICS Code on the Notice of Intent form (Appendix D);

• Added a field for latitude and longitude of the Pest Management Area on the Notice of Intent
form (Appendix D);

• Added the terms, "Fish and Wildlife Service Listed Resources of Concern" and "Lands of
Exclusive Federal Jurisdiction" to Appendix A, Definitions and Acronyms;

• Updated Appendix C, Areas Covered, to add permit numbers for other areas of Indian
Country and Lands of Exclusive Federal Jurisdiction.

Changes throughout the permit related to the ongoing Endangered Species Act (ESA)
consultation:

• Added the term, "Fish and Wildlife Service (FWS) Listed Resources of Concern" where the
permit already includes the term, "National Marine Fisheries Service (NMFS) Listed
Resources of Concern" to reflect proposed permit changes to address listed species and
designated critical habitats under the jurisdiction of FWS;

• Noted in Part 1.1.2.4 that aerial image of the pest management area(s) may not be needed if
EPA's geospatial mapping tool is available to provide supporting documentation when
selecting ESA eligibility Criterion A;

• Directs Decision-makers who are required to submit an NOI to include activities resulting in
a discharge to waters of the United States containing FWS Listed Resources of Concern on
the NOI (Part 1.2.2) and updated the NOI form to reflect this change (Appendix D);

• Updated Appendix I, Endangered Species Procedures, to clarify the procedures with a
worksheet format to guide Operators through the ESA eligibility criteria.

1. Clean Water Act

Section 301(a) of the Clean Water Act (CWA) provides that "the discharge of any pollutant by
any person shall be unlawful" unless the discharge is in compliance with certain other sections of
the Act. 33 U.S.C. § 1311(a). The CWA defines "discharge of a pollutant" as "(A) any addition
of any pollutant to navigable waters from any point source, (B) any addition of any pollutant to
the waters of the contiguous zone or the ocean from any point source other than a vessel or other
floating craft." Id. § 1362(12). A "point source" is any "discernible, confined and discrete
conveyance" but does not include "agricultural stormwater discharges and return flows from
irrigated agriculture." Id. § 1362(14). The term "pollutant" includes, among other things,
"garbage... chemical wastes, biological materials ...and industrial, municipal, and agricultural
waste discharged into water." Id § 1362(6).

A person may discharge a pollutant without violating the section 301 prohibition by
obtaining authorization to discharge (referred to herein as "coverage") under a section 402
NPDES permit (33 U.S.C. § 1342). Under section 402(a)(1), EPA may "issue a permit for the
discharge of any pollutant, or combination of pollutants, notwithstanding section 1311(a)" upon
meeting certain conditions required by the Act.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

2. NPDES Permits

An NPDES permit authorizes the discharge of a pollutant or pollutants into a receiving
water under certain conditions. The NPDES program relies on two types of permits: individual
and general. An individual permit is a permit specifically tailored for an individual discharger or
situations that require individual consideration. Upon receiving the appropriate permit
application(s), the permitting authority, e.g., EPA or a state, develops a draft permit for public
comment for that particular discharger based on the information contained in the permit
application (type of activity, nature of discharge, receiving water quality). Following
consideration of public comments, a final permit is then issued to the discharger for a specific
time period (not to exceed 5 years) with a provision for reapplying for further permit coverage
prior to the expiration date.

In contrast, a general permit covers multiple facilities/sites/activities within a specific
category for a specific period of time (not to exceed 5 years). For general permits, the permitting
authority, e.g., EPA or a state, develops and issues the permit in advance, with dischargers then
generally obtaining coverage under the permit through submission of a Notice of Intent (NOI). A
general permit is also subject to public comment prior to issuance. EPA is the permitting
authority for the geographic areas that have not been authorized by EPA to issue NPDES
permits. Each permitting authority should review their permittees and geographic area and
develop appropriate permits considering technology and water quality. In addition, states may
issue a permit that has different requirements from EPA's permit for similar types of discharges
of pollutants, as long as it satisfies the regulatory requirements of the NPDES program, the
CWA, and state law.

Under 40 CFR 122.28, general permits may be written to cover categories of point sources
having common elements, such as facilities that involve the same or substantially similar types
of operations, that discharge the same types of wastes, that require the same effluent limitations
or operating conditions, that require the same or similar monitoring, and that discharges are more
appropriately controlled under a general permit. The application of biological and chemical
pesticides is a category of dischargers that discharges the same types of wastes (i.e., pesticides)
such that same or similar permit conditions are appropriate. In addition, given the significant
number of pesticide operations requiring NPDES permit coverage and the discharges of
pollutants common to these operations, it makes administrative sense to issue the general permit,
rather than issuing individual permits to each Operator.

Courts have approved of the use of general permits. See e.g., Natural Res. Def. Council v.
Costle, 568 F.2d 1369 (D.C. Cir. 1977); EDC v. US EPA, 344 F.3d 832, 853 (9th Cir. 2003). The
general permit approach allows EPA to allocate resources in a more efficient manner and to
provide more timely coverage and may significantly simplify the permitting process for the
majority of pesticide dischargers. As with any permit, the CWA requires the general permit to
contain technology-based effluent limitations, as well as any more stringent limits when
necessary to meet applicable state water quality standards. State water quality standards apply in
the state and in the territorial seas, defined in section 502(8) of the CWA as extending three
miles from the baseline. Pacific Legal Foundation v. Costle, 586 F.2d 650, 655-656 (9th Cir.
1978); Natural Resources Defense Council, Inc. v. U.S. EPA, 863 F.2d 1420, 1435 (9th Cir.

1988).

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

3. History of Pesticide Application Regulation

EPA regulates the sale, distribution and use of pesticides in the United States under the
statutory framework of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) to
ensure that when used in conformance with FIFRA labeling directions, pesticides will not pose
unreasonable risks to human health and the environment. All new pesticides, for which
registration is required, must undergo a registration procedure under FIFRA during which EPA
assesses a variety of potential human health and environmental effects associated with use of the
product. Under FIFRA, EPA is required to consider the effects of pesticides on the environment
by determining, among other things, whether a pesticide "will perform its intended function
without unreasonable adverse effects on the environment," and whether "when used in
accordance with widespread and commonly recognized practice [the pesticide] will not generally
cause unreasonable adverse effects on the environment." 7 U.S.C. 136a(c)(5). In performing this
analysis, EPA examines the ingredients of a pesticide, the intended type of application site and
directions for use, and supporting scientific studies for human health and environmental effects
and exposures. The applicant for registration of the pesticide must provide specific data from
tests done according to EPA guidelines.

When EPA approves a pesticide for a particular use, the Agency imposes restrictions
through labeling requirements governing such use. The restrictions are intended to ensure that
the pesticide serves an intended purpose and avoids unreasonable adverse effects. It is illegal
under section 12(a)(2)(G) of FIFRA to use a registered pesticide in a manner inconsistent with its
labeling. States have primary authority under FIFRA to enforce "use" violations, but both the
states and EPA have ample authority to prosecute pesticide misuse when it occurs. 7 U.S.C.
13 6j (a)(2)(G).

4. Court Decisions Leading to the CWA Regulation Concerning Pesticide Applications

In the past, several courts have addressed the question of whether the CWA requires
NPDES permits for pesticide applications. These cases resulted in some confusion among the
regulated community and other affected citizens about the applicability of the CWA to pesticides
applied to waters of the United States.

On November 27, 2006, EPA issued a final rule (hereinafter called the "2006 NPDES
Pesticides Rule") clarifying two specific circumstances in which an NPDES permit was not
required to apply pesticides to or around water. They were: 1) the application of pesticides
directly to water to control pests; and 2) the application of pesticides to control pests that are
present over, including near, water where a portion of the pesticides will unavoidably be
deposited to the water to target the pests, provided that the application is consistent with relevant
FIFRA requirements in both instances. The rule became effective on January 26, 2007.

On January 7, 2009, the Sixth Circuit vacated EPA's 2006 NPDES Pesticides Rule under a
plain language reading of the CWA. National Cotton Council of America v. EPA, 553 F.3d 927
(6th Cir., 2009). The Court held that the CWA unambiguously includes "biological pesticides"
and "chemical pesticides" with residuals within its definition of "pollutant." Specifically, an
application of chemical pesticides that leaves no excess portion is not a discharge of a pollutant,
and the Applicator need not obtain an NPDES permit. However, chemical pesticide residuals are

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

pollutants as applied if they are discharged from a point source for which NPDES permits are
required. Biological pesticides, on the other hand, are always considered a pollutant under the
CWA regardless of whether the application results in residuals or not and require an NPDES
permit for all discharges of pollutants from a point source.

As a result of the Court's decision to vacate the 2006 NPDES Pesticides Rule, after
October 31, 2011, NPDES permits are required for discharges to waters of the United States of
biological pesticides, and of chemical pesticides that leave a residue. EPA and all NPDES-
authorized states and territories have developed and are implementing NPDES permits for
pollutant discharges resulting from pesticide applications. EPA Regional offices and state
NPDES authorities may issue additional general permits or individual permits if appropriate.

II. Structure of the PGP
1. General

This permit is written for the many specific areas of the country for which EPA remains the
NPDES permitting authority. The permit is constructed in such a way that each Region will sign
and issue the final PGP and include in that issuance CWA Section 401 certification language for
areas in their Region covered by the permit. Specifically, the permit provides coverage for
certain point source discharges of pollutants that occur in areas not covered by an authorized
state NPDES permit program and includes specific areas (e.g., states, territories, Indian Country,
or federal facilities) in all ten EPA Regions. The complete list of areas of geographic coverage of
this permit, along with the NPDES permit numbers are listed in Appendix C of the PGP.

States and territories that are authorized to issue NPDES permits will continue to
administer their own NPDES permits to cover such discharges of pollutants. Nothing in the
federal regulations precludes a state from adopting or enforcing requirements in their own
permits that are appropriate to address discharges of pollutants in their state or are more stringent
or more extensive than those required by EPA under the NPDES regulations. See CWA section
510. In fact, the CWA is meant to serve as a baseline for state environmental protection. The
CWA and corresponding NPDES regulations require that permits, at a minimum, include the
requirements detailed in 40 CFR 122.44 (but not necessarily in the same way as in this permit).
States are free to incorporate additional or different requirements that they feel are appropriate to
protect water quality. Similarly, how EPA and states interpret information from which permit
requirements are developed may differ. For example, the regulations, as written at 40 CFR
122.44(i) specify that monitoring requirements be included to assure compliance with permit
limitations. One permit writer may make a best professional judgment (BPJ) determination that
monitoring of discharges of pollutants reasonably should occur during pesticide application
while a second permit writer may make a BPJ determination that monitoring of discharges of
pollutants should reasonably be performed after pesticide application. It is reasonable that the
two different permit writers may come to different conclusions about how best to incorporate this
requirement into the permit.

Throughout this fact sheet (and permit), EPA uses consistent terms when referring to what
activity or discharge of pollutants will be eligible for coverage and who will be responsible to
comply with the terms of the permit. Specifically, the permit holder is referred to as the

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

"Operator." This term has a similar meaning to the term "permittee" which is also used in this
fact sheet; generally, the term permittee is specific to the period of time that an Operator or
contractor is actually covered under the permit. More details on how an Operator may obtain
permit coverage and the applicable permit requirements are provided in Part III of this fact sheet.

The permit is divided into nine parts: (1) Coverage Under This Permit, (2) Technology-
Based Effluent Limitations, (3) Water Quality-Based Effluent Limitations, (4) Monitoring, (5)
Pesticide Discharge Management Plan, (6) corrective action, (7) Recordkeeping and Annual
Reporting, (8) EPA contact information and mailing addresses, and (9) Permit Conditions
Applicable to Specific States, Indian Country, or Territories. Additionally, the permit includes
nine appendices with additional conditions and guidance for permittees: (A) Definitions,
Abbreviations, and Acronyms, (B) standard permit conditions, (C) Areas Covered, (D) Notice of
Intent Form, (E) Notice of Termination Form, (F) Pesticide Discharge Evaluation Worksheet,
(G) Annual Report Template, (H) Adverse Incident Report Template, and (I) Endangered
Species Procedures.

Operators should carefully read each part of the permit to assess whether or what portion of
the requirements in each part may apply to their activities. As will be discussed in more detail in
Part III of this fact sheet, the permit establishes different requirements for different types of
pesticide use patterns, different types of Operators, and different sizes of areas treated and
managed for the control of pests. The organization of the permit is intended to clarify the
applicable requirements for Operators to the greatest extent possible.

2. Conformance to Court Decisions

Similar to the previously issued PGPs, EPA has structured this draft PGP to conform to
relevant court decisions. One of these cases held that because the terms of the Nutrient
Management Plan (NMP) employed by concentrated animal feeding operations (CAFO) imposed
restrictions on discharges of pollutants, those restrictions amounted to effluent limitations that
needed to be made part of the permit and to be subject to public and permit writer review.

Water keeper Alliance, Inc. v. EPA, 399 F.3d 486 (2nd Cir. 2005). In this respect, this permit is
different from the CAFO requirements. In this permit, EPA explicitly establishes effluent
limitations in Parts 2 and 3 that are independent of any documentation and recordkeeping
requirements regarding implementation of the limitations. In a separate part of the permit (Part 5)
there is a requirement to develop a Pesticide Discharge Management Plan (PDMP). The PDMP
is not a limitation and does not itself impose requirements on discharges of pollutants. These are
already imposed by the limitations in Parts 2 and 3. The PDMP is rather a tool for those
Operators who are defined as Decision-makers to document, among other things, how Pest
Management Measures will be implemented to comply with the permit's effluent limitations.

Effluent Limitations in the PGP

Part 2 of the PGP contains the technology-based effluent limitations. Part 3 of the PGP
contains the water quality-based effluent limitations. These Parts of the permit contain effluent
limitations, defined in the CWA as restrictions on quantities, rates, and concentrations of
constituents that are discharged. CWA section 502(11). Violation of any of these effluent

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

limitations constitutes a violation of the permit. As is described in more detail in Part III.2 of this
fact sheet, under the CWA these effluent limitations can be narrative rather than numeric.

The technology-based effluent limitations set forth in Part 2 of the PGP require the
Operator to minimize the discharge of pollutants to waters of the United States from the
application of pesticides. Consistent with the control level requirements of the CWA, the term
"minimize" means to reduce and/or eliminate pollutant discharges to waters of the United States
through the use of Pest Management Measures to the extent technologically available and
economically achievable and practicable for the category or class of point sources covered under
the permit, taking into account any unique factors relating to the Operators to be covered under
the permit. The technology-based effluent limitations section is divided into two parts. The first
part applies to all Applicators and addresses the general requirement to minimize discharges
from the application of pesticides. In this part, all Applicators must minimize discharges of
pollutants by using only the amount of pesticide product per application and frequency of
pesticide applications necessary to control the target pest, performing regular maintenance
activities, calibrating and cleaning/repairing application equipment, and assessing weather
conditions in the treatment area. The second part requires certain Decision-makers to implement
pest management measures that involve the following: (1) identifying and assessing the pest
problem; (2) assessing effective pest management; and (3) following specified procedures for
pesticide application (see Part 2.2 of the PGP).

In addition to the technology-based effluent limitations, Part 3 of the PGP contains the
water-quality-based effluent limitations. The Operator must control its discharge of pollutants as
necessary to meet applicable water quality standards. Any discharge of pollutants that results in
an excursion of any applicable numeric or narrative EPA-approved state, territory, tribal or EPA-
promulgated water quality standard is prohibited. In general, based on the data included in the
record and the additional requirements in the permit, in addition to FIFRA's requirements and
the data and information upon which FIFRA registrations are based, EPA expects that
compliance with the technology-based effluent limitations and other terms and conditions in the
permit will meet applicable water quality-based effluent limitations. To date, after many years of
implementation of the prior permits, EPA does not have any evidence in the record that the
existing and prior permits are causing water quality problems. However, if at any time the
Operator or EPA determines that the discharge of pollutants causes or contributes to an excursion
of applicable water quality standards, the Operator must take corrective actions as required in
Part 6 of the PGP, and document and report the excursion(s) to EPA as required in Part 7 of the
PGP. Furthermore, consistent with Parts 3.0 and 6.3 of the PGP, EPA may impose additional
water quality-based limitations on a site-specific basis, or require the Operator to obtain coverage
under an individual permit, if information in an NOI, required reports, or from other sources
indicates that, after meeting the technology-based limitations in the permit, the discharges of
pollutants are not controlled as necessary to meet applicable water quality standards. EPA also
notes that among the eligibility requirements for coverage under the permit are requirements that
the permit does not cover discharges of any pesticide into a water impaired by a substance which
either is an active ingredient in that pesticide or is a degradate of such an active ingredient, or
into an Outstanding National Resource Water (40 C.F.R. 131.12), often referred to as a "Tier 3
water" (except for pesticide applications made to restore or maintain water quality or to protect
public health or the environment that either do not degrade water quality or only degrade water

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

quality on a short-term or temporary basis). These eligibility conditions further help EPA to issue
a general permit while protecting water quality on a water-body-specific basis.

Pesticide Discharge Management Plan (PDMP)

Distinct from the technology-based or water quality-based effluent limitation provisions in
the permit, Part 5.0 of the PGP requires Decision-makers that must submit an NOI and that are
large entities to prepare a PDMP to document the implementation of Pest Management Measures
being used to comply with the effluent limitations set forth in Parts 2.0 and 3.0 of the PGP. A
large entity, as defined in Appendix A of the PGP, is (1) a public entity that serves a population
greater than 10,000 people or (2) a private enterprise that exceeds the Small Business
Administration "size standards" as provided in 13 CFR 121.201.

In general, Part 5.0 of the PGP requires that the following be documented in the PDMP: (1)
pesticide discharge management team information; (2) problem identification; (3) pest
management options evaluation; (4) response procedures pertaining to spills and adverse
incidents; (5) documentation to support eligibility considerations under other federal laws, and
(6) signature requirements. The PDMP must be kept up-to-date and modified whenever
necessary to document any corrective actions as necessary to meet the effluent limitations in the
permit. NOTE: EPA is proposing changes to the contents of the PDMP. See Part III. 5 of this fact
sheet for more information.

The requirement to prepare a PDMP is not an effluent limitation because it does not restrict
quantities, rates, and concentrations of constituents that are discharged. CWA section 502(11).
Instead, the requirement to develop a PDMP is a permit "term or condition" authorized under
sections 402(a)(2) and 308 of the Act. Section 402(a)(2) states, "[t]he Administrator shall
prescribe conditions for [NPDES] permits to assure compliance with the requirements of
paragraph (1) of this subsection, including conditions on data and information collection,
reporting, and such other requirements as he deems appropriate." The PDMP requirements set
forth in the permit are terms or conditions under the CWA because the Operator is documenting
information on how it is complying with the effluent limitations (and inspection and evaluation
requirements) contained elsewhere in the permit. Thus, the requirement to develop a PDMP and
keep it updated is no different than other information collection conditions, as authorized by
section 402(a)(2), in other permits. Failure to have a PDMP, where required, is a violation of the
permit.1

While Part 2 of the PGP requires the Operator to select Pest Management Measures to meet
the effluent limitations in the permit, the Pest Management Measures themselves described in the
PDMP are not effluent limitations because the permit does not impose on the Operator the
obligation to comply with the PDMP; rather, the permit imposes on the Operator the obligation

1 This permit is also consistent with the decision in Texas Independent Producers and Royalty Owners Assoc.. et. al.
v. EPA. 410 F.3d 964 (7th Cir. 2005), where petitioners challenged EPA's issuance of the construction general
permit (CGP) that covers stormwater discharges. In that case, the Court found that neither the Stormwater Pollution
Prevention Plan (SWPPP) nor the Notices of Intent (NOIs) are permits or permit applications because they do not
amount to limits. 410 F.3d at 978. Further, the Court found that the permit requirement to develop a SWPPP is not
an effluent limitation. For the PGP, the PDMP serves a similar purpose as the CGP SWPPP.

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to meet the effluent limitations prescribed in Parts 2.0 and 3.0 of the PGP. Therefore, the
Operator is free to change as appropriate the Pest Management Measures used to meet the
effluent limitations contained in the permit. This flexibility helps ensure that the Operator is able
to adjust its practices as necessary to ensure continued compliance with the permit's effluent
limitations. However, the permit also contains a recordkeeping condition that requires that the
PDMP be updated with any such changes in the Operator's practices. See Part 5.2 of the PGP.
Thus, if an Operator's on-the-ground practices differ from what is in the PDMP, this would
constitute a violation of the permit's recordkeeping requirement to keep the PDMP up-to-date,
and not per se a violation of the permit's effluent limitations, which are distinct from the PDMP.
EPA recognizes, however, that because the PDMP documents how the Operator is meeting the
effluent limitations contained in the permit, not following through with actions identified by the
Operator in the PDMP as the method of complying with the effluent limitations in the permit is
relevant to evaluating whether the Operator is complying with the permit's effluent limitations.

Public Availability of Documents

Part 5.3 of the PGP requires that the Operator retain a copy of the current PDMP at the
address listed on the NOI and it must be immediately available, at the time of an onsite
inspection or upon request to EPA, state, tribal or local agencies governing wastewater
discharges of pollutants and/or pesticide applications, and representatives of the United States
Fish and Wildlife Service (FWS) or the National Marine Fisheries Service (NMFS). NOTE: EPA
is proposing to require Decision-makers to submit the PDMP with the NOI. See Part III. 5 of this
fact sheet for more information.

NOIs will be publicly available once submitted through the NPDES eReporting Tool
(NeT). The NOIs generally will be available to the public for 10 days before permit coverage
begins. During this time period, issues can be raised with EPA, which has the authority to deny
coverage. An annual report will also be publicly available once submitted through NeT.

3. Sharing of Responsibilities

This general permit was developed with the understanding that there may be more than one
responsible entity for a given discharge of pollutant. As structured, the permit provides for
sharing of responsibilities to meet the end goal of discharges of pollutants being in compliance
with permit requirements. The NPDES regulations state that "Operators" are responsible for
achieving permit compliance. Specifically, 40 CFR 122.21(b) clarifies that when an activity is
owned by one person, but it is operated by another person (e.g., contractor), it is the Operator's
duty to meet terms of the permit. EPA acknowledges, however, that in many instances the owner
may still perform Operator duties; as such, they may still be required to obtain permit coverage,
even in situations in which, for example, the owner hires a contractor to apply the pesticides to
control pests. The PGP includes a definition of "Operator" in Appendix A of PGP that is
intended to clarify this point, focusing on the fact that Operator control exists both at the
"Decision-maker" level about how to control pests, including financial considerations, as well as
at the pesticide Applicator" level (such as calibration of pesticide application equipment). In
these instances, both Operators, i.e., the Decision-Maker and the Applicator, are required to
obtain NPDES permit coverage; however, the permit strives to minimize any potential
duplication of effort by identifying which Operator is responsible for certain permit conditions.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

The permit clarifies these responsibilities by identifying whether EPA expects these activities to
be performed by all Operators, or just the Decision-maker or just the Applicator.

Entities such as subcontractors that are hired by an owner or other entity but are under the
supervision of such owner or entity generally are not Operators. Similarly, entities are likely not
an Operator if, for example, they own the land, but the activities are being performed outside of
their control (e.g., a public entity is spraying for mosquitoes over private property, or a private
party is spraying for weeds on public lands leased from the federal government).

EPA encourages Operators to use already prepared information and explore possible cost
savings by sharing responsibilities for implementing aspects of this permit. For example, a
mosquito control district may have developed something for their FIFRA program, and they
could assume the overall coordination of an integrated pest management program while a hired
contractor may be responsible for minimizing the pollutant discharge and for site monitoring and
maintaining and calibrating pesticide application equipment. In instances where multiple
Operators are responsible for the discharge from larger pesticide application activities, some
form of written explanation of the division of responsibilities should be documented. However,
any and all Operators covered under the permit are still responsible for any violation that may
occur, though EPA may consider this written division of responsibilities when determining the
appropriate enforcement response to a violation.

III. Summary of Draft 2026 PGP Conditions

1. Coverage Under the Draft 2026 PGP
1.1 Eligibility

1.1.1 Activities Covered

The activities covered under this draft 2026 PGP remain unchanged from the 2021 PGP.
Only Operators meeting the eligibility requirements outlined in the draft 2026 PGP may be
covered under the permit. If an Operator does not meet the eligibility provisions described in Part
1.1 of the PGP, the Operator's point source discharges of pollutants to waters of the United
States2 from the application of pesticides will be in violation of the CWA, unless the Operator
has obtained coverage under another permit, or the CWA exempts these discharges of pollutants
from NPDES permit requirements. The activities covered by this permit generally include the
use patterns and types of pest control activities described in the vacated 2006 NPDES Pesticides
Rule. Under CWA section 502(14), agricultural stormwater and irrigation return flow are exempt
from NPDES permits. Also, applications that do not reach waters of the United States do not
need permit coverage. Thus, the draft 2026 PGP covers the discharge of pollutants (biological
pesticides and chemical pesticides which leave a residue) to waters of the United States resulting
from the following use patterns: (1) Mosquito and Other Flying Insect Pest Control; (2) Weed

2 For information on the definition of "waters of the United States" and litigation updates, see
https://www.epa. gov/nwpr.

10

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

and Algae Control; (3) Animal Pest Control; and (4) Forest Canopy Pest Control, as summarized
below:

Mosquito and Other Flying Insect Pest Control

This use pattern includes the application, by any means, of chemical and biological
insecticides and larvicides into or over water to control insects that breed or live in, over,
or near waters of the United States. Applications of this nature usually involve the use of
ultra-low volume sprays or granular larvicides discharged over large swaths of mosquito
breeding habitat and often are performed several times per year.

Weed and Algae Pest Control

This use pattern includes the application, by any means, of contact or systemic herbicides
to control vegetation and algae (and plant pathogens such as fungi) in waters of the
United States and at water's edge, including ditches and/or canals. Applications of this
nature typically are single spot pesticide applications to control infestations or staged
large scale pesticide applications intended to control pests in several acres of waterway.
Pesticide applications in a treatment area may be performed one or more times per year to
control the pest problem.

Animal Pest Control

This use pattern includes the application, by any means, of pesticides into waters of the
United States to control a range of animal pests for purposes such as fisheries
management, invasive species eradication, or equipment operation and maintenance.
Applications of this nature are often made over an entire or large portion of a waterbody
as typically the target pests are mobile. Multiple pesticide applications to a waterbody for
animal pest control are often made several years apart.

Forest Canopy Pest Control

This use pattern includes pest control projects in, over, or to forest canopies (aerially or
from the ground) to control pests in the forest canopy where waters of the United States
exist below the canopy. Applications of this nature usually occur over large tracts of land
and are typically made in response to specific pest outbreaks. EPA understands that for
this use pattern pesticides will be unavoidably discharged into waters of the United States
in the course of controlling pests over a forest canopy as a result of pesticide application.
These pests are not necessarily aquatic (e.g., airborne non-aquatic insects) but are
detrimental to industry, the environment, and public health. Note: EPA recognizes that
mosquito adulticides are applied to forest canopies, and this application is covered under
the "Mosquito and Other Flying Insect Pest Control" use pattern.

In the 2006 NPDES Pesticides Rule, EPA expressly noted that the rule did not cover either
"spray drift" - the airborne movement of pesticide sprays away from the target application site
into waters of the United States - or applications of pesticides to terrestrial agricultural crops
where runoff from the crop, either as irrigation return flow or agricultural stormwater, discharges
into waters of the United States.

Consistent with the 2006 NPDES Pesticides Rule and the previously issued PGPs, this
draft 2026 PGP does not cover spray drift resulting from pesticide applications. Instead, to
address spray drift, EPA is actively engaged in several initiatives to help minimize pesticide drift

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problems such as: (1) evaluating potential for drift as a routine part of pesticides risk
assessments; (2) in collaboration with experts, improving scientific models and methods for
estimating drift and risks from drift; (3) strengthening labeling for new pesticides and when re-
evaluating older pesticides; (improving the clarity and enforceability of product label directions
and drift management restrictions; and (4) promoting applicator education and training programs.
More information on EPA's work on reducing pesticide drift is available at
https://www.epa.gov/reducing-pesticide-drift.

Irrigation return flow (such as runoff from a crop field due to irrigation of that field) and
agricultural stormwater runoff do not require NPDES permits, as exempted from the definition of
point source under section 502(14) of the CWA. Neither the 2006 NPDES Pesticides Rule, the
Sixth Circuit Court vacatur of that rule, nor any version of the PGP have changed in any way the
determination of whether certain types of stormwater discharges are required to obtain permit
coverage, or under which permit coverage is required. This is true whether the discharge of
pollutants contains pesticides or pesticide residues resulting from the application of pesticides. In
particular, non-agricultural stormwater that may contain pesticides would not be eligible for
coverage under the permit, and is not required to obtain NPDES permit coverage unless
otherwise required under section 402(p) of the CWA. Existing stormwater permits for
construction, industrial activity, and regulated municipal separate storm sewer systems (MS4s)
already address pesticides in stormwater from those sources. Thus, stormwater is either: (a)
already subject to NPDES permit requirements pursuant to section 402(p) of the CWA or (b) is a
discharge for which NPDES permit coverage is not currently required under section 402(p). The
regulations that specify what types of stormwater require NPDES permits can be found in 40
CFR §122.26 and 122.30-122.37.

EPA determined that the four use patterns included in the draft 2026 PGP would
encompass the majority of pesticide applications that would result in point source discharges of
pollutants to waters of the United States and generally represent the use patterns intended to be
addressed by the 2006 rule that is now vacated. This permit does not cover, nor is permit
coverage required, for pesticides applications that do not result in a point source discharge of
pollutants to waters of the United States, such as for the purpose of controlling pests on
agricultural crops, forest floors, or range lands. However, the application of herbicides in waters
of the United States and the control of pests on plants grown in waters of the United States, such
as perennial obligate hydrophytes, is within the permit's scope of coverage. This fact sheet does
not identify every activity which may involve a point source discharge of pollutants to waters of
the United States that would require a permit; rather, the fact sheet focuses on the activities for
which coverage under the draft 2026 PGP is available. The existence of this general permit does
not alter the requirement that discharges of pollutants to waters of the United States that are not
covered by this permit be covered by an individual permit or another general permit.

Scope of Permit

The Sixth Circuit Court of Appeals found that if a chemical pesticide leaves any excess or
residue after performing its intended purpose, such excess or residue would be considered a
pollutant under the CWA. The Court also found that, unlike chemical pesticides, not only would
the residue and excess quantities of a biological pesticide be considered a pollutant, but so too
would the biological pesticide itself under the CWA.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

As defined in 40 CFR 122.2, "Pesticide residue for the purpose of determining whether
an NPDES permit is needed for discharges of pollutants to waters of the United States from
pesticide application, means that portion of a pesticide application that is discharged from a point
source to waters of the United States and no longer provides pesticidal benefits. It also includes
any degradates of the pesticide."

A permit would not be necessary if it is determined that pesticide residual does not enter
waters of the United States. The Operator applying pesticides with a discharge to waters of the
United States can support their determination with scientific data. Such data should show what
level of the pesticide can be detected in water, and at what level in water the pesticide provides a
pesticidal benefit. Such data should address the properties of the chemical pesticide under
different water conditions (e.g., different pH, organic content, temperature, depth, etc.) that
might affect the pesticide's properties.

EPA offers the following guidance with respect to the use patterns of chemical pesticides
covered by this general permit.

1. If the application of a chemical pesticide is made over waters of the United States to
control pests over the water, any amount of the pesticide that falls into waters of the
United States is "excess" pesticide and would require coverage by an NPDES permit.

2. If the application of a chemical pesticide is made into waters of the United States to
control a pest in such waters, any amount of the pesticide that remains in those waters
and no longer provides any pesticidal benefit is a "residual" and would require
coverage by an NPDES permit. See 40 CFR 122.2 for the definition of pesticide
residue.

3. This permit authorizes discharges of pollutants associated with four categories of
pesticide application activities: mosquito and other flying insect pest control, weed and
algae pest control, animal pest control, forest canopy pest control. As noted above, only
point source discharges of pollutants to waters of the United States require a permit,
and it is beyond the scope of this fact sheet to identify all specific activities that do or
do not require a permit. However, to the extent that activities that fall within the four
covered categories require a permit, they can be authorized by this general permit if all
eligibility requirements are met. For two of the categories, weed and algae pest control
and animal pest control, the permit specifies that covered activities include applications
to control pests "in water and at water's edge." EPA intends for the phrase "at water's
edge" to allow coverage of activities targeting pests that are not necessarily "in" the
water but are near the water such that control of the pests results in a point-source
discharge of pollutants to waters of the United States. The category forest canopy pest
control is for applications to a forest canopy. EPA intends that this can include both
mature and immature forest canopies, including canopies that may not be continuously
connected, where control of pests associated with the canopy {i.e., branches and leaves
of the trees) results in a point source discharge of pollutants to waters of the United
States.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

For purposes of this permit, EPA is relying on existing regulatory definitions in 40 CFR
174.3 and 158.2100(a) developed under FIFRA to define the term "biological pesticides." For
purposes of this permit, EPA identifies biological pesticides (also called "biopesticides" under
FIFRA regulations) to include microbial pesticides [40 CFR 158.2100(b)], biochemical
pesticides [40 CFR 158.2000(a)(1)] and plant-incorporated protectants. [40 CFR 174.3]

EPA recognizes that there are many site-specific situations which will determine whether a
pesticide application operation needs permit coverage. EPA is not attempting to define all such
situations in this fact sheet. Additionally, any pesticide application activities that do not fall
within the four use patterns covered by this permit will require coverage under some other
NPDES permit if those activities result in point source discharges of pollutants to waters of the
United States. However, the Agency does want to make it clear that to the extent pesticide
application operations need permit coverage, this permit is available for the four pesticide use
categories.

Additionally, as described in Part 1.4 of this fact sheet, the permit does not cover discharges
of pollutants that, by law, are not required to obtain NPDES permit coverage. Of note, the CWA
specifically excludes from the definition of point source, "agricultural stormwater discharges and
return flow from irrigated agriculture." Nothing in this permit changes the effect of those
statutory exemptions.

See Appendix D of this fact sheet for discussion on the cost impact and the universe of
Operators covered under this permit.

1.1.2 Limitations on Coverage

1.1.2.1 Discharges of Pollutants to Water Quality Impaired Waters

This permit specifies eligibility requirements for coverage under this general permit for
discharge of pollutants to impaired waters. The requirements remain unchanged from the
previously issued PGPs. Coverage under the permit is only available for certain discharges of
pollutants to impaired waters. Discharges of pollutants to waters which are impaired for a
substance which is not an active ingredient in that pesticide or a degradate of such an active
ingredient are eligible for coverage. Discharges of pollutants to waters impaired for temperature
or some other indicator parameter, or for physical impairments such as "habitat alteration" are
also eligible for draft 2026 PGP coverage, unless otherwise notified by EPA. Conversely, the
permit is not available for the discharge of any pesticide to water that is impaired for a substance
that is an active ingredient in that pesticide or a degradate of such an active ingredient. For
example, application of the pesticide copper sulfate to a waterbody impaired for either copper or
sulfates would not be eligible for coverage under this permit, because copper sulfate can degrade
into these two substances. In this instance, the Operator would have to choose between obtaining
coverage under an individual permit for such a discharge or selecting some other means of pest
management, e.g., using mechanical means or a different pesticide active ingredient.

For this permit, EPA determined that it does not have information warranting a limitation
for all impaired waters regardless of the impairment. In fact, the application of a pesticide to
water in some instances actually improves the quality of the water, such as when used to control
algae growth that can deplete oxygen levels in water. It is important to note that this permit

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allows EPA, based on additional information, to opt not to approve coverage under the draft
2026 PGP, or at a later date to require an Operator covered under the draft 2026 PGP to apply for
coverage under an individual permit.

For purposes of this permit, impaired waters are those that have been identified by a state,
territory, tribe, or EPA pursuant to Section 303(d) of the CWA as not meeting applicable water
quality standards. Impaired waters for purposes of the PGP include both waters with EPA-
approved and EPA-established Total Maximum Daily Loads (TMDLs), and those for which EPA
has not yet approved or established a TMDL. (A list of impaired waters, along with the
pollutants or pollution identified as the cause of the impairment is available at
https://www.epa.gov/trndl). Since the 303(d) list provides the most readily-available evidence of
impairment, Operators should use it when deciding whether their discharges of pollutants meet
the eligibility requirements regarding waterbodies impaired for specific pesticides. Thus, these
requirements will further ensure protection of water quality.

Also, several states have listed waters as impaired for "pesticides" but have not identified
the specific pesticide for which the waterbody is impaired. Without additional information
suggesting that the waterbody is impaired for a specific active ingredient or degradate of that
active ingredient, EPA is providing coverage under this permit for discharges of pollutants to
waters that are impaired generally for "pesticides." The Agency expects that as these impaired
waters are further assessed, specific pesticides or classes of pesticides will be identified as the
cause of the impairment, at which point dischargers will no longer be eligible to obtain permit
coverage under the draft 2026 PGP for discharges of those named pesticide active ingredients or
degradates of such. Additional discussion of existing impairments identified for which pesticides
are identified as the source of the impairment is provided in Part III.3 of this fact sheet.

1.1.2.2 Discharges of Pollutants to Waters Designated as Tier 3 for Antidegradation
Purposes

This permit specifies requirements for coverage under this general permit for discharges of
pollutants to Tier 3 waters. These waters are called "Outstanding National Resource Waters" in
the regulations. 40 C.F.R. 131.12. The requirements remain unchanged from the previously
issued PGPs. This permit provides coverage for discharges of pollutants made to restore or
maintain water quality or to protect public health or the environment that either do not degrade
water quality or only degrade water quality on a short-term or temporary basis. This is consistent
with EPA's longstanding view that "[sjtates may allow some limited activities which result in
temporary and short-term changes in water quality. Such activities are considered to be
consistent with the intent and purpose of [a Tier 3 water] " 48 FR 51400, 51403 (1983).

States and tribes provide the most stringent level of antidegradation protection, i.e., Tier 3
protection. These waters are often regarded as the highest quality waters of the United States, but
the Tier 3 designation also provides special protection for waters of exceptional ecological
significance, i.e., those which are important, unique, or sensitive ecologically. Except for certain
temporary changes, Tier 3 protection means that water quality cannot be lowered in such waters.
In broad terms, EPA's view of "temporary" is weeks and months, not years. States and tribes
make the decision of which water bodies to designate as Tier 3. A list of Tier 3 waters in areas

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

where the draft 2026 PGP is available can be accessed on the Internet at
https://www.epa.gov/npdes/pesticide-permitting.

This permit requires additional documentation and reporting for discharges of pollutants to
Tier 3 waters. See Part 5.1.2 of the PGP. Any Decision-maker planning to discharge to a Tier 3
water must submit a Notice of Intent (NOI) consistent with Part 1.2.2 of the PGP. NOIs for such
discharges of pollutants are required to identify the Tier 3 water by name, and provide a
discussion of the environmental problem and demonstration that the pollutant discharge is
necessary to protect water quality, the environment, and/or public health. This NOI requirement
includes the requirement for any Decision-maker already covered under the draft 2026 PGP who
wants to discharge to a Tier 3 water at a later date, to submit an updated NOI containing the
information identified above for discharges of pollutants to Tier 3 waters. Additionally, NOIs for
any discharges of pollutants to Tier 3 waters must be submitted at least 10 days before beginning
discharge unless discharges of pollutants are in response to a Declared Pest Emergency Situation,
in which case, an NOI is due for such discharges of pollutants no later than 15 days after
beginning discharge (if water contains NMFS Listed Resources of Concern) or 30 days after
beginning discharge (if no NMFS Listed Resources of Concern). Decision-makers are required
to submit an NOI consistent with the earliest due date identified in Table 1-2 of the PGP. NOTE:
EPA is proposing the same ESA procedures for FWS under the draft 2026 PGP as described
above for NMFS. In response to a Declared Pest Emergency Situation, an NOI would be due for
such discharges of pollutants no later than 15 days after beginning discharge if the water contains
FWS Listed Resources of Concern and/or NMFS Listed Resources of Concern, or 30 days after
beginning discharge if the water contains no FWS Listed Resources of Concern and NMFS
Listed Resources of Concern.

Of note, some states have adopted alternative approaches to designating Tier 2 or Tier 3
waters. These are collectively referred to as "Tier 2.5" waters since they fall between Tiers 2 and
3 in terms of characteristics and regulations supporting them. Tier 2.5 waters are commonly
described as providing protection more stringent than Tier 2 but allowing some added flexibility
that a Tier 3 water would not. Refer to Memorandum from William Diamond (Former Director,
Standards and Applied Science Division) to Victoria Binetti (Chief, Region III, Program and
Support Branch), June 13, 1991. Examples of Tier 2.5 waters exist in Massachusetts, which
designates "outstanding resource waters" (ORWs). These waters have exceptional sociologic,
recreational, ecological and/or aesthetic values and are subject to more stringent requirements
under both the Massachusetts Water Quality Standards and the Massachusetts Stormwater
Management Standards. ORWs include vernal pools certified by the Natural Heritage Program
of the Massachusetts Department of Fisheries and Wildlife and Environmental Law
Enforcement, all Class A designated public water supplies with their bordering vegetated
wetlands, and other waters specifically designated. The draft 2026 PGP does not restrict
eligibility for discharges of pollutants to Tier 2.5 waters.

1.1.2.3 Discharges of Pollutants Currently or Previously Covered by Another Permit

Part 1.1.2.3 of the PGP describes situations where an Operator is ineligible for coverage
under this permit because of coverage under another permit. The permit provisions remain
unchanged from the previously issued PGPs. These include discharges of pollutants currently
covered under an NPDES permit and discharges of pollutants from activities where the

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associated NPDES permit has been or is in the process of being denied, terminated, or revoked
by EPA (although this last provision does not apply to the routine reissuance of permits every
five years).

1.1.2.4 Endangered and Threatened Species and Critical Habitat Protection

The draft 2026 PGP specifies procedures to assist in protecting federally-listed endangered
and threatened species and federally designated critical habitats under the Endangered Species
Act (ESA). The 2021 PGP includes procedures specific to protecting species and critical habitat
managed by NMFS but not FWS. The proposed procedures for this draft 2026 PGP are carried
over from EPA's 2021 PGP and would now apply to both NMFS and FWS threatened and
endangered species and critical habitat. EPA is currently in consultation with the Services
(NMFS and FWS) for the reissuance of this permit. Based on the results of consultation with the
Services, EPA may include additional or altered conditions in the final permit. At this point, EPA
is proposing to extend the various terms and conditions that the 2021 PGP applied to "NMFS
Listed Resources of Concern" to also apply to "FWS Listed Resources of Concern" throughout
the draft 2026 PGP to address listed species and designated critical habitats under the jurisdiction
of FWS. This approach could change depending on the final consultation with the Services.

The provisions described below reflect requirements that were added in the 2021 PGP
following formal consultation with NMFS and its issuance of a Biological Opinion. The
provisions described below are designed to ensure that discharges of pollutants covered under
the 2021 PGP are not likely to result in any short or long term adverse effects to NMFS Listed
Resources of Concern, except as provided in eligibility Criterion B, C, and, for 60 days, D, in
Part 1.1.2.4 of the PGP. These permit provisions include eligibility criteria for permit coverage
as well as requiring compliance with technology-based effluent limitations in Part 2.2 of the PGP
and recordkeeping and reporting requirements for Decision-makers with discharges of pollutants
to waters of the United States containing NMFS Listed Resources of Concern.

The 2021 PGP, under Part 1.1.2.4, requires Operators to certify that they are eligible for
permit coverage under one of the six eligibility criteria (A-F) as follows and to provide the
supporting documentation with the NOI:

Criterion A. Pesticide application activities will not result in a point source discharge to
one or more waters of the United States containing National Marine Fisheries Service (NMFS)
Listed Resources of Concern, as defined in Appendix A, for this permit. In this case, no further
certification is necessary. Decision-makers not otherwise required to submit an NOI are not
required to do so merely to check Criterion A. However, Decision-makers who must submit an
NOI anyway should check Criterion A if they do not discharge to waters of the United States
containing NMFS Listed Species of Concern. Decision-makers are required to attach to the NOI
an aerial image of the pest management area(s) using the maps and resources at
https://www.epa.gov/npdes/pesticide-permitting-ESA-procedures. NOTE: EPA is proposing the
same ESA procedures for FWS under the draft 2026 PGP as described above for NMFS. To
select Criterion A under the draft 2026 PGP, pesticide application activities must not result in a
point source discharge to waters of the United States containing FWS Listed Resources of
Concern and NMFS Listed Resources of Concern. The requirement for Decision-makers to
attach to the NOI an aerial image of the pest management area(s) under the draft 2026 PGP may

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be streamlined with the development of a geospatial mapping tool. If the tool is available,
Decision-makers would be able to create a shapefile of the pest management area when
submitting the NOI.

Criterion B. Pesticide application activities will discharge to one or more receiving waters
of the United States containing NMFS Listed Resources of Concern, as defined in Appendix A,
but consultation with NMFS under section 7 of the ESA has been concluded for pesticide
application activities covered under this permit. Consultations can be either formal or informal,
and would have occurred only as a result of a separate federal action. The consultation addressed
the effects of pesticide discharges and discharge-related activities on federally-listed threatened
or endangered species and federally-designated critical habitat, and must have resulted in either:

i. A biological opinion from NMFS finding no likely jeopardy to listed species and no
destruction/adverse modification of federally-designated critical habitat and the
Reasonable and Prudent Measures to minimize take have been or are in the process of
being implemented; or

ii. Written concurrence from NMFS with a finding that the pesticide discharges and
discharge-related activities are not likely to adversely affect federally-listed species or
federally-designated critical habitat.

Decision-makers are required to provide any tracking numbers of identifiers associated with the
consultation (e.g., IPaC number, ECO number), the Services field office/regional office(s)
providing the consultation, any copies of supporting correspondence with FWS and/or NMFS,
identification of the federal action agency(ies) involved, and the date the consultation was
completed. NOTE: EPA is proposing the same ESA procedures for FWS under the draft 2026
PGP as described above for NMFS. To select Criterion B under the draft 2026 PGP, consultation
with Services under section 7 of the ESA for FWS Listed Resources of Concern and/or NMFS
Listed Resources of Concern must have been concluded for the pesticide application activities
covered under the permit. Decision-makers would also need to submit documentation from FWS
and/or NMFS to support selecting this Criterion.

Criterion C. Pesticide application activities will discharge to one or more waters of the
United States containing NMFS Listed Resources of Concern, as defined in Appendix A, but any
"take" of these resources associated with such pesticide application activities has been authorized
through NMFS' issuance of a permit under section 10 of the ESA, and such authorization
addresses the effects of the pesticide discharges and discharge-related activities on federally-
listed species and federally-designated critical habitat. (The term "take" means to harass, harm,
pursue, hunt, shoot, wound, kill, trap, capture, or collect, or to attempt to engage in any such
conduct. See Section 3 of the Endangered Species Act, 16 U.S.C. § 1532(19).) Decision-makers
are required to provide any tracking numbers of identifiers associated with the section 10 permit,
the date the section 10 permit was granted, whether the permit was granted by the FWS and/or
NMFS, and the field office/regional office(s) granting the permit. NOTE: EPA is proposing the
same ESA procedures for FWS under the draft 2026 PGP as described above for NMFS. To
select Criterion C under the draft 2026 PGP, permit under section 10 of the ESA for FWS Listed
Resources of Concern and/or NMFS Listed Resources of Concern must have been issued for the
pesticide application activities covered under the permit. Decision-makers would also need to
submit documentation from FWS and/or NMFS to support selecting this Criterion.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

Criterion D. Pesticide application activities were, or will be, discharged to one or more
waters of the United States containing NMFS Listed Resources of Concern, as defined in
Appendix A, but only in response to a Declared Pest Emergency Situation. Decision-makers
must provide EPA with their rationale supporting the determination whether the discharge is
likely to result in any short or long term adverse effects to NMFS Listed Resources of Concern,
including the description of appropriate measures to be undertaken to avoid or eliminate the
likelihood of any short or long term adverse effects. Decision-makers are required to provide
information on anticipated applications and provide a rationale as to why any short or long term
adverse effects are not expected or why the pest emergency poses a greater threat to the ESA-
listed species than the pesticide application. NOTE: EPA is proposing the same ESA procedures
for FWS under the draft 2026 PGP as described above for NMFS. To select Criterion D under
the draft 2026 PGP, Decision-makers must provide rationale supporting the determination
whether the discharge is likely to result in any short or long term adverse effects to FWS Listed
Resources of Concern and/or NMFS Listed Resources of Concern.

Criterion E. Pesticide application activities for which permit coverage is being requested
in the NOI will discharge to one or more waters of the United States containing NMFS Listed
Resources of Concern, as defined in Appendix A. Eligible discharges include those where the
Decision-maker includes in the NOI written correspondence from NMFS that pesticide
application activities performed consistent with appropriate measures will avoid or eliminate the
likelihood of any short or long term adverse effects to NMFS Listed Resources of Concern.
Eligibility under this criterion is contingent upon the Decision-maker following the measures
described in correspondence from NMFS designed to avoid or eliminate the likelihood of any
short or long term adverse effects. NOTE: EPA is proposing the same ESA procedures for FWS
under the draft 2026 PGP as described above for NMFS. To select Criterion E under the draft
2026 PGP, Decision-makers must provide written correspondence from FWS and/or NMFS that
pesticide application activities performed consistent with appropriate measures will avoid or
eliminate the likelihood of any short or long term adverse effects to FWS Listed Resources of
Concern and/or NMFS Listed Resources of Concern.

Criterion F. Pesticide application activities for which permit coverage is being requested
in the NOI will discharge to one or more waters of the United Stated containing NMFS Listed
Resources of Concern, as defined in Appendix A. Eligible discharges include those from
pesticide application activities that are demonstrated by the Decision-maker as not likely to result
in any short or long term adverse effects to NMFS Listed Resources of Concern or that the pest
poses a greater threat to the NMFS Listed Resources of Concern than does the discharge of the
pesticide. Decision-makers must provide EPA with their documentation demonstrating the basis
for their finding. NOTE: EPA is proposing the same ESA procedures for FWS under the draft
2026 PGP as described above for NMFS. To select Criterion F under the draft 2026 PGP,
Decision-makers must demonstrate that pesticide application activities will not likely result in
any short or long term adverse effects to FWS Listed Resources of Concern and/or NMFS Listed
Resources of Concern.

Criteria E and F, at least 30 days prior to beginning to discharge, require an Operator to
demonstrate:

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

-	Pesticides being discharged or to be discharged are known not to cause any short or
long term adverse effects, or are or will be discharged at concentrations determined
not to cause any short or long term adverse effects, to NMFS Listed Resources of
Concern (Criterion F), or

-	NMFS Listed Resources of Concern are or will not be exposed to pesticide
pollutants produced by the discharge (e.g., species will not occur in the discharge
area during that time of year, the species will not be present in the hydrologic unit
in which the discharge will occur, the species is not present because of the presence
of the pest being controlled, etc) (Criterion F), or

Other considerations that demonstrate the discharge is not likely to result in any
short or long term adverse effects to NMFS Listed Resources of Concern (Criterion
F), or

They have obtained written correspondence from NMFS indicating that pesticide
application activities performed consistently with appropriate measures will avoid
or eliminate the likelihood of any short or long term adverse effects to Listed
Resources of Concern. Eligibility under this criterion is contingent upon the
Decision-maker following the measures described in correspondence from NMFS
designed to avoid or eliminate the likelihood of any short or long term adverse
effects (Criterion E).

Any Decision-maker planning to discharge pollutants to waters of the United States
containing NMFS Listed Resources of Concern, as defined in Appendix A of the PGP, must
submit an NOI consistent with Part 1.2.2 of the PGP. The specific requirements of the PGP NOI
are identified in the NOI form provided in Appendix D of the PGP. Also, refer to Appendix I of
the PGP for the ESA Review Procedures to determine eligibility prior to submittal of the NOI.
This NOI requirement includes the requirement for any Decision-maker already covered under
the permit who discharges pollutants to any waters of the United States containing NMFS Listed
Resources of Concern, as defined in Appendix A of the PGP, that were not identified in a
previously submitted NOI, to submit an updated NOI containing the information identified in
Appendix D of the PGP. Additionally, NOIs for any discharges of pollutants to waters of the
United States containing NMFS Listed Resources of Concern, as defined in Appendix A of the
PGP, must be submitted at least 30 days before beginning discharge. EPA may authorize certain
discharges of pollutants in less than 30 days, but no fewer than 10 days, for any discharges of
pollutants under Criterion B, C, or E of Part 1.1.2.4 of the PGP. Where eligibility is determined
consistent with Criterion D, response to a Declared Pest Emergency Situation, an NOI is due for
such discharges of pollutants no later than 15 days after beginning discharged. NOTE: EPA is
proposing the same ESA procedures for FWS under the draft 2026 PGP as described above for
NMFS. Under the draft 2026 PGP, a Decision-maker planning to discharge pollutants to waters
of the United States containing FWS Listed Resources of Concern and/or NMFS Listed
Resources of Concern must submit an NOI. The NOI must be revised to include either of these
Resources not identified in the previously submitted NOI. NOIs for discharges to waters of the
United States containing FWS Listed Resources of Concern or NMFS Listed Resources of
Concern must be submitted at least 30 days before beginning discharge.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

1.2 Authorization to Discharge Pollutants Under this Permit

1.2.1 How to Obtain Authorization

The NPDES general permit regulations, at 40 CFR § 122.28(b)(2), require that Operators
submit an NOI to obtain coverage under an existing general permit for which that discharge is
eligible. However, those regulations, at §122.28(b)(2)(v), provide that at the discretion of the
Director (which, for the draft 2026 PGP, is EPA), certain discharges of pollutants can be
authorized under a general permit without submitting an NOI where EPA finds that an NOI
would be inappropriate for such discharges. In making such a finding, EPA must consider the
following criteria: the type of discharge; the expected nature of the discharge; the potential for
toxic and conventional pollutants in the discharges; the expected volume of the discharges of
pollutants; other means of identifying discharges of pollutants covered by the permit; and the
estimated number of discharges of pollutants to be covered by the permit.

This draft 2026 PGP is requiring submission of an NOI for certain discharges of pollutants
and is providing automatic coverage for certain other discharges of pollutants. The requirements
remain unchanged from the previously issued PGPs. EPA is requiring submission of an NOI for
certain discharges of pollutants and is providing automatic coverage for certain other discharges
of pollutants for which EPA determined it would be inappropriate to require an NOI. EPA is
exempting Operators of pesticide research and development activities from the need to submit an
NOI because these activities are typically smaller and in many instances, are already covered
under FIFRA's section 5 (experimental use permits). Similarly, the draft 2026 PGP exempts
these activities from many requirements of the permit where such activities are inconsistent with
the research plan.

As discussed in Appendix D of this fact sheet, EPA expects a large number of discharges
of pollutants from the application of pesticides spanning a wide range of Operators and activities
will require NPDES permit coverage. Conditions and requirements in this permit remain largely
unchanged from the previously issued PGPs. See Appendix F for EPA's consideration of the
regulatory criteria in §122.28(b)(2)(v).

1.2.2 Decision-makers Required to Submit an NOI

To obtain authorization under the draft 2026 PGP, Operators (Decision-makers and
Applicators) must meet the Part 1.1 eligibility requirements of the PGP. If required by Part 1.2.2
of the PGP, certain Decision-makers must submit a complete and accurate NOI no later than the
appropriate deadline described in Part 1.2.3 of the PGP.

Table 1-1 in Part 1.2.2 of the PGP identifies which Decision-makers are or will be required
to submit an NOI. Based on the analysis outlined in Part 1.2.1 above, For-Hire Applicators, who
are not Decision-makers as defined in Appendix A of the PGP, are not required to submit NOIs.
In addition, Decision-makers who apply pesticides to relatively small areas are not required to
submit NOIs (except for certain Operators that the Agency finds have a significant role in pest
control for public health and environmental protection and should be expected to provide
Agency notice of such activities). Nonetheless, EPA emphasizes that even if an NOI is not
required, Operators covered automatically are still subject to all applicable requirements. EPA is
requiring NOIs from the following types of Decision-makers:

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

- Decision-makers exceeding an annual treatment area threshold;

- Other Decision-makers specifically in the business of pest control;

- Decision-makers discharging pollutants to Tier 3 waters; and

- Decision-makers discharging pollutants to waters of the United States containing
NMFS Listed Resources of Concern, as defined in Appendix A of the PGP.

This permit provision remains unchanged from the previously issued PGPs. See Appendix
G for a more detailed discussion of EPA's rationale for requiring NOIs for these categories of
Decision-makers. NOTE: EPA is proposing the same ESA procedures for FWS under the draft
2026 PGP as described above for NMFS. EPA will require NOIs from Decision-makers
discharging pollutants to waters of the United States containing FWS Listed Resources of
Concern.

Contents of the NOI

Pursuant to 40 CFR §122.28(b)(2)(ii), the contents of any NOI must be specified in the
general permit and require the submission of information necessary for adequate program
implementation, including at a minimum:

- the legal name and address of the Owner or Operator,

- the facility name and address,

- type of facility or discharges of pollutants,

- the receiving stream(s), and

- signed in accordance with §122.22.

NOTE: EPA is proposing to require the submission of the one or more six-digit North American
Industry Classification System (NAICS) codes/descriptions, if available. This data element is
required to be shared with EPA when authorized NPDES programs approve NPDES permit
coverage after June 12, 2021 (i.e., two years after the effective date of the 2019 NPDES
Applications and Program Updates Rule). See February 12, 2019; 84FR3324. EPA is also
proposing to require submission of the latitude and longitude of the pest management area(s).
This is one of the standard data elements from the NPDES Electronic Reporting Rule. See
October 22, 2015; 80FR64063.

The specific requirements of the draft 2026 PGP NOI are identified in the NOI form
provided in Appendix D of the PGP but include those elements identified in the regulations
described above with three additional data elements that are important to fully characterize the
activities for which permit coverage is being provided, namely identification of:

- pesticide use activities that trigger the PGP requirements to develop a pesticide
discharge management plan and submit an annual report;

- impaired water(s) and/or Tier 3 water(s) for which permit coverage is being requested
for discharges of pollutants to these waters and demonstration of eligibility for such
discharges; and

- whether pollutant discharges will be to waters of the United States containing NMFS
Listed Resources of Concern, and, if so, what pest(s) are to be controlled; the pesticide
product(s) to be discharged; the planned quantity and rate of discharge(s) of pollutants;

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

the number of planned discharges of pollutants; and signed certification by the
Decision-maker that one of the six eligibility criteria in Part 1.1.2.4 of the PGP have
been met. EPA recognizes the implementation of pest management measures as
specified in the permit may involve a degree of "adaptive management" such that exact
timing and quantities of applications cannot be determined in advance for the duration
of the permit. EPA expects the Decision-maker to provide the required information to
the extent feasible and consistent with the implementation of the selected pest
management measures. NOTE: EPA is proposing the same ESA procedures for FWS
under the draft 2026 PGP as described above for NMFS. The NOI would also ask
whether pollutant discharges will be to waters of the United States containing FWS
Listed Resources of Concern.

Also, the draft 2026 PGP requires Decision-makers to submit changes to previous NOI
forms where, for example, coverage for an additional discharge of pollutants not included in the
original NOI is being requested. EPA expects these NOI change requests to be submitted
primarily in four instances: (1) coverage for a new or expanded pest management area or a new
pesticide use pattern is being requested, (2) discharge to a not-previously identified Tier 3 water
is identified for permit coverage, or (3) discharge to any not-previously identified waters of the
United States containing NMFS Listed Resources of Concern, as defined in Appendix A of the
PGP, is being requested or (4) changes in the treatment area, pesticide product, method or rate of
application, or approximate dates of applications for discharges of pollutants to waters of the
United States containing NMFS Listed Resources of Concern. In cases where this information
was previously provided to the extent feasible and consistent with the implementation of selected
pest management practices, a revised NOI is not required as long as the discharge continues to be
consistent with the information provided in the original NOI submission. In these four instances,
Decision-makers are required to submit revised NOIs that reflect changes in the areas and types
of activities for which coverage is being requested. NOTE: EPA is proposing the same ESA
procedures for FWS under the draft 2026 PGP as described above for NMFS. An updated NOI
would also be needed for discharges to any not-previously identified waters of the United States
containing FWS Listed Resources of Concern or changes in the treatment area, pesticide product,
method or rate of application, or approximate dates of applications for discharges of pollutants to
waters of the United States containing FWS Listed Resources of Concern.

1.2.3 Discharge Authorization Date

For any discharges of pollutants occurring after the effective date of the final permit and
for which Operators are not required to submit an NOI, Operators will receive permit coverage
for those discharges of pollutants under the draft 2026 PGP. Dischargers who obtained automatic
coverage under the 2021 PGP (i.e., Operators who are not required to submit an NOI) and
continue to discharge pollutants after the effective date of the final permit will receive
uninterrupted permit coverage. Decision-makers required to submit NOIs, as detailed in Part

1.2.2	of the PGP, are authorized consistent with the timeframes and provisions detailed in Part

1.2.3	of the PGP. Decision-makers who are required to submit an NOI must begin complying
with requirements in Part 2.2 of the PGP as of the discharge authorization date.

NOIs are required from Decision-makers according to the schedule detailed in Table 1-2 in
the PGP and as described below:

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

- Other than for discharges of pollutants in response to a Declared Pest Emergency
Situation or that are to NMFS Listed Resources of Concern, both of which are
described below, Decision-makers who discharge after the effective date of the final
permit will be authorized 10 days after EPA posts on its public Internet website, at
https://www.epa.gov/npdes/pesticide-permitting. receipt of a complete and accurate
NOI unless EPA places a hold on the authorization (i.e., delay authorization). NOIs
submitted electronically will be posted on the NPDES website instantaneously with the
Operator authorized to discharge 10 days after the posting, providing EPA does not
place a hold on the authorization for that NOI. EPA will send automatic confirmation
of receipt of NOIs and of discharge authorization. The Agency may place an
authorization on hold if the Agency determines, including based on information
provided by other interested parties (e.g., FWS, NMFS), that the Operator may not be
eligible for PGP coverage. See Part 1.1 of the PGP for the eligibility criteria. Thus, an
NOI must be submitted no later than 10 days before the first discharge for any
discharges of pollutants occuring after the effective date of the final permit.

- Any Decision-maker who discharges pollutants in response to a Declared Pest
Emergency Situation, as defined in Appendix A of the PGP, that is not to waters of the
United States containing NMFS Listed Resources of Concern, for which that activity
triggers the requirement to submit an NOI, is authorized to discharge pollutants
immediately; however, a complete and accurate NOI is required to be submitted no
later than 30 days after beginning to discharge. This delay in NOI submission and
immediate authorization is to allow pest managers the opportunity to respond to pest
emergencies without delay.

- In any Declared Pest Emergency Situation for discharges of pollutants to waters of the
United States containing NMFS Listed Resources of Concern, the discharges of
pollutants are authorized for at least 60 days or until EPA determines that the
discharges of pollutants may not continue (or places additional conditions on the
discharge) due to concerns related to compliance with the ESA-related conditions of the
2021 PGP. These Decision-makers must file an NOI no later than 15 days after
beginning to discharge pollutants. The NOI must identify:

1. The location of the pest management area in detail or include a map of the location;

2. Pest(s) to be controlled;

3. Pesticide product(s) to be discharged and method of application;

4. Planned quantity and rate of discharge(s) for each method of application;

5. Number of planned discharges of pollutants;

6. Approximate date(s) of planned discharge(s) of pollutants; and

7. Whether the discharge of pollutants is likely to result in any short or long term
adverse effects to NMFS Listed Resource of Concern, including the description of
appropriate measures to be undertaken to avoid or eliminate the likelihood of any
short or long term adverse effects on that identified NMFS Listed Resource of
Concern.

For discharges of pollutants that have already occurred prior to NOI submission, items
1 through 6 above must also be identified in that NOI.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for

publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.

Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

the Federal Register.

-	In any Declared Pest Emergency Situation in areas with waters of the United States
containing NMFS Listed Resources of Concern, NMFS will have 30 days after
submission of an NOI (e.g., when EPA posts on the Internet receipt of a complete and
accurate NOI) to provide EPA with a determination as to whether NMFS believes the
eligibility criteria of "not likely to result in any short or long term adverse effects to
listed species or designated critical habitat" has been met, per Part 1.1.2.4 of the PGP
(see also 50 CFR 402.14), could be met with conditions that NMFS identifies, or has
not been met. EPA expects to rely on NMFS' determination in deciding whether to
disallow continued permit coverage or if additional conditions are necessary to meet the
eligibility criteria of "not likely to result in any short or long term adverse effects to
listed species or designated critical habitat." See Part 1.1.2.4 of the PGP. See also 50
CFR 402.14. If NMFS does not provide EPA with a recommendation within 30 days of
EPA posting on the Internet receipt of a complete and accurate NOI, authorization for
these discharges of pollutants will continue. If EPA identifies additional permit
conditions, or includes additional permit conditions recommended by NMFS, as
necessary to qualify discharges of pollutants as eligible for coverage beyond 60 days,
those conditions remain in effect for the life of the permit. EPA will advise the
Decision-maker within 15 days of receiving a determination from NMFS whether the
discharge of pollutants or discharges of pollutants qualify for coverage beyond the 60-
day authorization provided. If the decision maker does not hear from EPA, the decision
maker may assume that permit authorization continues unless notified otherwise. This
approach provides a reasonable amount of time for Operators to quickly respond to any
Declared Pest Emergency Situation {i.e., 60 days after beginning to discharge
pollutants), yet provides the Agency with an opportunity to ensure that subsequent
discharges of pollutants are controlled as necessary to protect water quality and any
NMFS Listed Resources of Concern.

-	For any discharges of pollutants to waters of the United States containing NMFS Listed
Resources of Concern and beginning on or after the effective date of the final permit an
NOI will need to be submitted no later than 30 days before the first discharge occurs.
NOIs submitted electronically will be posted on the NPDES website instantaneously
with the Operator authorized to discharge 30 days after the posting, providing EPA
does not place a hold on the authorization for that NOI. EPA will send automatic
confirmation of receipt of NOIs and of discharge authorization. The additional
timeframe allows NMFS to have sufficient time to review NOI submissions as a result
of discharges of pollutants to waters of the United States containing NMFS Listed
Resources of Concern, as defined in Appendix A of the PGP. EPA may authorize
certain discharges of pollutants in less than 30 days, but no fewer than 10 days, after
submission of an NOI for any discharges of pollutants under eligibility Criterion B, C,
or E, of Part 1.1.2.4 of the PGP. This is because under eligibility Criterion B and C,
Operators would have already consulted with NMFS and under criterion E, the
Operator would have received a written letter from NMFS that the discharge of
pollutants will not adversely affect NMFS Listed Resources of Concern. Early
submittal and review of NOIs will help ensure that any issues are addressed and
resolved in a timely manner so that appropriate pesticide applications can proceed as
planned. The Agency may place an authorization on hold if the Agency determines,

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

including based on information provided by other interested parties and from the
Services' review, that the Operator may not be eligible for PGP coverage. In
determining whether to withhold permit authorization under this permit, EPA expects
to rely on NMFS expertise in making a determination as to whether there is likely to be
adverse effect. Within 30 days after EPA posts on the Internet receipt of a complete and
accurate NOI, for those discharges of pollutants to waters of the United States
containing NMFS Listed Resources of Concern, as defined in Appendix A of the PGP,
NMFS will provide EPA with a determination as to whether NMFS has determined the
eligibility criteria of "not likely to result in any short or long term adverse effects to
listed species or designated critical habitat" has been met, could be met with conditions
the NMFS identifies, or has not been met. EPA expects to rely on NMFS'
determination in deciding whether to disallow continued permit coverage or if
additional conditions are necessary. EPA notes that it may be advantageous to the
Decision-maker to work with NMFS prior to submitting the NOI, and to obtain written
correspondence from NMFS, if possible, that pesticide application activities performed
consistent with appropriate measures will avoid or eliminate the likelihood of any short
or long term adverse effects. In this case, as noted above, EPA may authorize
discharges of pollutants in as few as 10 days after the NOI is submitted, although the
operator may not assume authorization before 30 days unless specifically so notified by
EPA.

NOTE: EPA is proposing to provide FWS the same process and timelines for the review of NOIs
as outlined above for NMFS.

NOIs submitted electronically will be posted on the NPDES website instantaneously with
the Operator authorized to discharge pollutants 10 or 30 days after the posting, providing EPA
does not place a hold on the authorization for that NOI. EPA will send automatic confirmation of
receipt of NOIs and of discharge authorization.

The draft 2026 PGP contains standard language that provides EPA with the authority to
modify permit terms or terminate permit coverage as appropriate. NMFS and any other interested
persons may provide information to EPA noting any concerns with authorized discharges of
pollutants, including those resulting from Declared Pest Emergency Situations. EPA will
consider that information and take future action as appropriate. As provided in the draft 2026
PGP, in general, EPA may take the following actions:

Part 1.3 - Require Operators to apply for and/or obtain authorization to discharge under
either an NPDES individual permit or an alternative NPDES general permit.

Appendix B, Standard Permit Conditions, 40 CFR 122.41(a) Duty to comply -

Terminate, revoke and reissue, or modify a permit for any permit noncompliance, that is
also grounds for enforcement action.

Part 1.2.3; Part 6.3; Appendix B, Standard Permit Conditions, 40 CFR 122.41(f)
Permit actions - Modify, revoke and reissue, or terminate a permit for cause.

NOTE: EPA is proposing the same NOI process for FWS under the draft 2026 PGP as described
above for NMFS. FWS may also provide information to EPA noting any concerns with

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

authorized discharges of pollutants, including those resulting from Declared Pest Emergency
Situations.

1.2.4 Continuation of this Permit

The draft 2026 PGP specifies procedures for continued coverage under a general permit if
the permit expires prior to a replacement permit being issued. The procedures remain unchanged
from EPA's previously issued PGPs. In short, the expired permit would remain in full force and
effect in accordance with the Administrative Procedure Act (5 U.S.C. 558(c)) and EPA's
implementing regulations at 40 CFR 122.6. Any permittee granted coverage prior to the permit's
expiration date will automatically remain covered by the continued permit until the earliest of:

(a) Authorization under a new version of the PGP following timely and accurate submittal
of a complete NOI (if required);

(b) The processing and posting of a Notice of Termination (NOT) consistent with Part
1.2.5.1 of the PGP;

(d) A formal permit decision by EPA not to reissue the general permit, at which time EPA
will identify a reasonable time period for covered dischargers to seek coverage under an
alternative general permit or an individual permit. Coverage under this permit will
cease when coverage under another permit is granted/authorized; or

(e) EPA has informed the permittee that the permittee's discharges of pollutants are no
longer covered under the permit.

If EPA fails to issue a final general permit prior to the expiration of a previous general
permit the permit will be administratively continued in accordance with section 558(c) of the
Administrative Procedure Act (5 U.S.C. 558(c)) and EPA's implementing regulations at 40 CFR
122.6 and will remain in force and effect for discharges of pollutants that were covered prior to
expiration. However, EPA does not have the authority to provide coverage under an
administratively extended permit to entities not authorized prior to the expiration date of the
permit.

1.2.5 Terminating Coverage

The draft 2026 PGP specifies procedures for terminating coverage under this general
permit. The procedures remain unchanged from EPA's previously issued PGPs.

1.2.5.1 Submitting a Notice of Termination

To terminate coverage under the permit, any Decision-maker who submitted an NOI to
obtain permit coverage is required to submit a NOT in accordance with information identified in
Appendix E of the PGP. The Decision-maker's authorization to discharge pollutants under the
permit terminates at midnight of the day that a complete NOT is processed and posted on EPA's
website (https://www.epa.gov/npdes/pesticide-permitting). Dischargers automatically covered
(as identified in Part 1.2.3 of the PGP) are automatically terminated upon permanent cessation of
discharge consistent with any of the criteria identified in Part 1.2.5.2 of the PGP.

EPA requires Decision-makers who file an NOT to notify EPA that its obligation to
manage pollutant discharges is no longer necessary for one of the EPA-approved reasons (as

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

described in Part III. 1.2.5.2 of this fact sheet). If EPA determines that the Decision-maker has
not satisfied one of the conditions in Part 1.2.5.2 of the PGP for being able to submit an NOT
(e.g., the Decision-maker continues to have a discharge of pollutants) then the notice is not valid
and the Decision-maker must continue to comply with the conditions of the PGP. Likewise, if
EPA determines that the NOT is incomplete, the Decision-maker may be found to be in violation
of reporting requirements.

1.2.5.2 When to Submit a Notice of Termination

Once all point source discharges associated with pesticide application have ceased, the
Decision-maker must submit an NOT, as described in Part 1.2.5.1 of the PGP, within 30 days
after one or more of the following conditions have been met: (1) a new Decision-maker has taken
over responsibility for the pest control activities; (2) all discharges have ceased from the
application of pesticides for which permit coverage was obtained and discharges of pollutants are
not expected during the remainder of the permit term for any of the use patterns as identified in
Part 1.1.1 of the PGP, or (3) coverage under an individual permit or alternative general permit
has been obtained for all discharges of pollutants required to be covered by an NPDES permit,
unless coverage was obtained consistent with Part 1.3 of the PGP, in which case, coverage under
this permit will terminate automatically.

In the PGP, EPA is requiring an NOT from Operators who on their own switch to a
different permit to provide the Agency with clear notice that the Operator's discharge of
pollutants is not covered under two NPDES permits. Operators who terminate coverage based on
an EPA request consistent with Part 1.3 of the PGP are not required to submit an NOT.

1.2.5.3 Termination for Operators not Required to Submit an NOI

Operators covered under the PGP who are not required to submit an NOI are terminated
from permit coverage when there is no longer a discharge from the application of pesticides, or
the discharges of pollutants are covered under an NPDES individual permit or alternative
NPDES general permit. Operators not required to submit an NOI are also not required to submit
an NOT.

1.3 Alternative Permits

The draft 2026 PGP specifies requirements and procedures for coverage under an
alternative permit. The requirements and procedures remain unchanged from EPA's previously
issued PGPs.

1.3.1 Requirements for Coverage Under an Alternative Permit

EPA may require an individual permit (in accordance with 40 CFR 122.28(b)(3)(ii)) or
coverage under an alternative NPDES general permit instead of the PGP. The regulations also
provide that any interested party may petition EPA to take such an action. The issuance of the
individual permit or alternative NPDES general permit is in accordance with 40 CFR part 124
and provides for public comment and appeal of any final permit decision. The circumstances in
which such an action would be taken are set forth at 40 CFR 122.28(b)(3).

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

1.3.2 Operator Requesting Coverage under an Alternative Permit

After receiving permit coverage under the PGP, the Operator may request to be excluded
from such coverage by applying for an individual permit or alternative NPDES general permit.
In this case, the Operator must submit an individual permit application in accordance with 40
CFR 122.28(b)(3)(iii), along with a statement of reasons supporting the request, to EPA at the
applicable EPA Regional Office listed in Part 8.2 of the PGP. The request may be granted by
issuance of an individual permit or authorization of coverage under an alternative general permit
if the reasons are adequate to support the request. Under this scenario, if an individual permit is
issued, or authorization to discharge pollutants under an alternative general permit is granted,
coverage under this permit is automatically terminated under 40 CFR 122.28(b)(3)(iv) on the
effective date of the individual permit or the date of authorization of coverage under the
alternative general permit.

Part 1.3.2 of the PGP explains an Operators ability to apply for coverage under an
individual permit in lieu of coverage under this general permit and describes the steps to take to
be excluded from this permit after being authorized under this permit. Cases where an individual
NPDES permit may be required are described fully in 40 CFR 122.28(b)(3)(iii). The following
are the pertinent situations for this permit where an individual permit may be necessary:

a) A Water Quality Management plan containing requirements applicable to such point
sources is approved;

b) Circumstances have changed since the time of the request to be covered so that the
discharger is no longer appropriately controlled under the general permit, or either a
temporary or permanent reduction or elimination of the authorized discharge is
necessary; or

c) The discharge(s) is a significant contributor of pollutants. In making this determination,
EPA may consider the following factors:

(1) The location of the discharge of pollutants with respect to waters of the United
States;

(2) The size of the discharge of pollutants;

(3) The quantity and nature of the pollutants discharged to waters of the United States;
and

(4) Other relevant factors.

EPA may require an Operator to apply for an individual permit only if EPA notifies the
Operator in writing that a permit application for an individual permit is required. See 40 CFR
124.52. This notice must include a brief statement of the reasons for this decision, an application
form, a statement setting a time for the Operator to file the application, information on appeals
rights, and a statement that on the effective date of the individual NPDES permit the general
permit as it applies to the individual Operator shall automatically terminate. EPA may grant
additional time upon request of the applicant.

When an individual NPDES permit is issued to an Operator otherwise subject to a general
NPDES permit, the applicability of the general permit to the individual NPDES Operator is
automatically terminated on the effective date of the individual permit.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

Note that an individual permit is required for discharges from the application of pesticides
to waters where such waters are impaired by a substance which either is an active ingredient in
that pesticide or is a degradate of such an active ingredient, and for certain applications of
pesticides to Tier 3 waters where such applications are not made to restore or maintain water
quality or to protect public health or the environment in such a way that they either do not
degrade water quality or only degrade water quality on a short-term or temporary basis. In these
cases, authorization under this general permit would not have been available in the first place.

1.4 Severability

Invalidation of a portion of this permit does not necessarily render the whole permit
invalid. If any provisions of this permit are reviewed and vacated by a court, only those
provisions vacated will be deemed invalidated by EPA. The remainder of the permit conditions
will remain in effect. EPA will evaluate the effect of such invalidation on a case-by-case basis.

1.5 Other Federal and State Laws

Part 1.5 of the PGP includes the following language: "Operators must comply with all
other applicable federal and state laws and regulations that pertain to the application of
pesticides. For example, this permit does not negate the requirements under FIFRA and its
implementing regulations to use registered pesticides consistent with the product's labeling. In
fact, applications in violation of certain FIFRA requirements could also be a violation of the
permit and therefore a violation of the CWA (e.g., exceeding label application rates).
Additionally, other laws and regulations might apply to certain activities that are also covered
under this permit (e.g., United States Coast Guard regulations)."

This part of the PGP is intended to clarify that Operators are still required to comply with
other applicable laws, and that merely complying with the conditions of this permit may not
result in compliance with all other applicable regulations. In fact, compliance with certain permit
terms expressly requires Operators to comply with other laws to demonstrate compliance with
this permit. For example, the PGP requires Operators to use "Pest Management Measures" to
"minimize" discharges of pollutants. As these terms are defined in Appendix A of the PGP,
Operators must use practices that comply with, among other things, "relevant legal
requirements" to reduce and/or eliminate pollutant discharges to waters of the United States.

1.6 Federally Listed Endangered and Threatened Species and Designated Critical

Habitat.

Part 1.6 of the PGP clarifies that Operators are required to comply with conditions and/or
requirements for discharges of pollutants to waters of the United States resulting from any ESA
Section 7 consultation or ESA Section 10 permit as a result of a separate federal action for
pesticides application activities covered under this permit. Operators seeking coverage under this
permit do not have a separate obligation to consult with FWS or NMFS under Section 7 of the
ESA prior to submitting an NOI. As the Federal entity issuing this permit, EPA has the statutory
requirement, and obligation to consult with FWS and NMFS. However, if any consultation has
been conducted between an Operator and the Services because of other actions to consult, and
the results of that consultation are relevant to an Operator's expected discharge(s), then this

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

permit obliges the Operator to comply with any additional conditions or limits on the discharge
of pollutants resulting from such consultation.

2. Effluent Limitations

Background

The CWA requires that all point source discharges of pollutants from existing facilities, or
in this case, pesticide applications, meet technology-based effluent limitations3 (TBELs)
representing the applicable levels of control. 33 U.S.C. 1311(b)(l)(A)(BPT), (b)(2)(A)(BAT),
(b)(2)(E)(BCT). Additionally, water quality-based effluent limitations (WQBELs) are required
where the technology-based effluent limitations are not sufficient to protect applicable water
quality standards. 33 U.S.C. 1311(b)(1)(C). Water quality-based requirements will be discussed
in greater depth in Part III. 3 of this fact sheet. The technology-based effluent limitations
contained in the PGP are non-numeric and constitute the levels of control that reduce the area
and duration of the discharge of pollutants to waters of the United States.

The Clean Water Act Requires EPA to Develop Effluent Limitations that Represent the
Following:

Best Practicable Control Technology Currently Available (BPT)

The CWA requires BPT effluent limitations for conventional, toxic, and non-conventional
pollutants. Section 304(a)(4) designates the following as conventional pollutants: biochemical
oxygen demand (BOD), total suspended solids, fecal coliform, pH, and any additional pollutants
defined by the Administrator as conventional. The Administrator designated oil and grease as an
additional conventional pollutant on July 30, 1979. 40 CFR 401.16. EPA has identified 65
pollutants and classes of pollutants as toxic pollutants, of which 126 specific substances have
been designated priority toxic pollutants. 40 CFR 401.15 and 40 CFR Part 423 Appendix A. All
other pollutants are considered to be non-conventional.

In specifying BPT, under CWA section 301(b)(1)(A); 304(b)(1)(B); 40 CFR 125.3(d)(1),
EPA evaluates a number of factors. EPA first considers the total cost of applying the control
technology in relation to the effluent reduction benefits. The Agency also considers the age of
the equipment and facilities, the processes employed, and any required process changes,
engineering aspects of the control technologies, non-water quality environmental impacts
(including energy requirements), and such other factors as the EPA Administrator deems
appropriate. Traditionally, EPA establishes BPT effluent limitations based on the average of the
best performance of facilities within the industry of various ages, sizes, processes, or other

3 Natural Res. Def. Council, Inc. v. EPA, 673 F.2d 400, 403 (D.C. Cir. 1982) (noting that "section 502(11) defines
'effluent limitation' as 'any restriction' on the amounts of pollutants discharged, not just a numerical restriction";
holding that section of CWA authorizing courts of appeals to review promulgation of "any effluent limitation or
other limitation" did not confine the court's review to the EPA's establishment of numerical limitations on pollutant
discharges, but instead authorized review of other limitations under the definition) (emphasis added). In Natural
Res. Def. Council, Inc. v. Costle, 568 F.2d 1369 (D.C. Cir. 1977), the D.C. Circuit stressed that when numerical
effluent limitations are infeasible, EPA may issue permits with conditions designed to reduce the level of effluent
discharges of pollutants to acceptable levels.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

common characteristics. Where existing performance is uniformly inadequate, BPT may reflect
higher levels of control than currently in place in an industrial category if the Agency determines
that the technology can be practically applied.

Best Conventional Pollutant Control Technology (BCT)

The 1977 amendments to the CWA required EPA to identify effluent reduction levels for
conventional pollutants associated with BCT for discharges from existing industrial point
sources. CWA section 301(b)(2)(E); 304(b)(4)(B); 40 CFR 125.3(d)(2). In addition to
considering the other factors specified in section 304(b)(4)(B) to establish BCT limitations, EPA
also considers a two part "cost-reasonableness" test. EPA explained its methodology for the
development of BCT limitations in 1986. 51 FR 24974 (July 9, 1986).

Best Available Technology Economically Achievable (BAT)

For toxic pollutants and non-conventional pollutants, EPA includes technology-based
effluent limitations based on BAT in NPDES permits. CWA section 301(b)(2)(A); 304(b)(2)(B);
40 CFR 125.3(d)(3). In establishing BAT, the technology must be technologically "available"
and "economically achievable." The factors considered in assessing BAT include the cost of
achieving BAT effluent reductions, the age of equipment and facilities involved, the process
employed, potential process changes, non-water quality environmental impacts, including energy
requirements and other such factors as the EPA Administrator deems appropriate. The Agency
retains considerable discretion in assigning the weight accorded to these factors. BAT limitations
may be based on effluent reductions attainable through changes in an Operator's processes and
operations. Where existing performance is uniformly inadequate, BAT may reflect a higher level
of performance than is currently being achieved within a particular subcategory based on
technology transferred from a different subcategory or category. BAT may be based upon
process changes or internal controls, even when these technologies are not common industry
practice.

The PGP contains effluent limitations that correspond to required levels of technology-
based control (BPT, BCT, BAT) for discharges of pollutants under the CWA. Some effluent
limitations have been established by examining other existing laws, requirements, and practices.
Because these are demonstrated practices, EPA has found that they are technologically available
and economically practicable (BPT) or achievable (BAT).

Technology-Based Effluent Limitations

Technology-based effluent limitations are in many cases established by EPA in regulations
known as effluent limitations guidelines, or "ELGs." EPA establishes these regulations for
specific industry categories or subcategories after conducting an in-depth analysis of that
industry. The CWA sets forth different standards for the ELGs based upon the type of pollutant
or the type of permittee involved. Where EPA has not issued effluent guidelines for an industry,
EPA and State permitting authorities establish effluent limitations for NPDES permits on a case-
by-case basis based on their best professional judgment. See 33 U.S.C. § 1342(a)(1); 40 C.F.R. §
125.3(c)(2).

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

As stated above, the CWA establishes two levels of technology-based controls. The first
level of control, "best practicable control technology currently available," or "BPT" applies to all
pollutants. CWA section 304(b)(1)(B); 33 U.S.C. 1314(b)(1)(B). BPT represents the initial stage
of pollutant discharge reduction, designed to bring all sources in an industrial category up to the
level of the average of the best source in that category. See EPA v. National Crushed Stone
Association, 449 U.S. 64, 75-76 (1980). In the second level of control, all point sources are
required to meet effluent limitations based on "best conventional pollutant control technology,"
or "BCT" CWA section 304(b)(4)(B); 33 U.S.C. 1314(b)(4)(B) or "best available technology
economically achievable," or "BAT" CWA section 301(b)(2)(A); 33 U.S.C. 1311(b)(2)(A),
depending on the types of pollutants discharged. BCT applies to conventional pollutants, listed at
40 CFR 401.16 (biological oxygen demand (BOD), pH, fecal coliform, TSS, and oil and grease).
BAT applies to toxic and non-conventional pollutants. Technology-based limitations are to be
applied throughout industry without regard to receiving water quality. Appalachian Power Co. v.
EPA, 671 F.2d 801 (4th Cir. 1982).

EPA's Authority to Include Non-Numeric Technology-Based Limitations in this Permit

All NPDES permits are required to contain technology-based effluent limitations. 40 CFR
§§ 122.44(a)(1) and 125.3. CWA sections 301(b)(1)(A) for (BPT); 301(b)(2)(A) for (BAT); and
301(b)(2)(E) for (BCT). Technology-based effluent limitations in the PGP represent the BPT (for
conventional, toxic, and non-conventional pollutants), BCT (for conventional pollutants), and
BAT (for toxic pollutants and non-conventional) levels of control for the applicable pollutants.
When EPA has not promulgated effluent limitation guidelines for an industry, or if an Operator
is discharging a pollutant not considered in the development of the effluent guideline, permit
limitations are based on the best professional judgment (BPJ, sometimes also referred to as "best
engineering judgment") of the permit writer. 33 U.S.C. § 1342(a)(1); 40 CFR 125.3(c). See
Student Public Interest Group v. Fritzsche, Dodge & Olcott, 759 F.2d 1131, 1134 (3rd Cir. 1985);
American Petroleum Inst. v. EPA, 787 F.2d 965, 971 (5th Cir. 1986). For the PGP, the
technology-based effluent limitations are based on BPJ decision-making because no ELG
applies.

Under EPA's regulations, non-numeric effluent limitations are authorized in lieu of
numeric limitations, where "[njumeric effluent limitations are infeasible." 40 CFR 122.44(k)(3).
As far back as 1977, courts have recognized that there are circumstances when numeric effluent
limitations are infeasible and have held that EPA may issue permits with conditions (e.g.,
narrative effluent limitations or best management practices) designed to reduce the level of
effluent discharges to acceptable levels. Natural Res. Def. Council, Inc. v. Costle, 568 F.2d 1369,
1380 (D.C.Cir. 1977).

Through the Agency's NPDES permit regulations, EPA interpreted the CWA to allow best
management practices (BMPs) to take the place of numeric effluent limitations under certain
circumstances. Federal regulations at 40 CFR §122.44(k), entitled "Establishing limitations,
standards, and other permit conditions (applicable to state NPDES programs ...)," provides that
permits may include BMPs to control or abate the discharge of pollutants when: (1) "[authorized
under section 402(p) of the CWA for the control of stormwater discharges"; or (2) "[njumeric
effluent limitations are infeasible." 40 CFR § 122.44(k).

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Courts have held that the CWA does not require EPA to set numeric limitations where such
limits are infeasible. Citizens Coal Council v. EPA, 447 F.3d 879, 895-96 (6th Cir. 2006). The
Sixth Circuit cited Waterkeeper Alliance, Inc. v. EPA, 399 F.3d 486, 502 (2nd Cir. 2005), stating
"site-specific BMPs are effluent limitations under the CWA." Additionally, the Sixth Circuit
cited Natural Res. Def. Council, Inc. v. EPA, 673 F.2d 400, 403 (D.C.Cir. 1982) noting that
"section 502(11) [of the CWA] defines 'effluent limitation' as 'any restriction' on the amounts of
pollutants discharged, not just a numerical restriction."4

For the PGP, EPA is using the term "Pest Management Measures," as defined in Appendix
A of the PGP, to represent those practices used to meet the non-numeric effluent limitations.

EPA's Decision to Include Non-Numeric Technology-Based Effluent Limitations in the
PGP and Rationale for Why the Limits Represent the Appropriate (BPT, BCT, or BAT)
Level of Control.

As described above, numeric effluent limitations are not always feasible because the
discharges of pollutants pose challenges not presented by other types of NPDES-regulated
discharges of pollutants. The technology-based effluent limitations remain unchanged from
EPA's previously issued PGPs. The technology-based effluent limitations in this permit are non-
numeric based on the following facts:

- The point in time for which a numeric effluent limitation would apply is not easily
determinable. For discharges of pollutants from the application of pesticides, the
discharges of pollutants can be highly intermittent with those discharges of pollutants
not practically separable from the pesticide application itself. For example, the
discharge from the application of a chemical pesticide to waters of the United States is
a discharge of pollutants when there is a residual remaining in the ambient water after
the pesticide is no longer serving its intended purpose {i.e., acting as a pesticide against
targeted pests in the applied medium). This discharge of pollutants also will have
combined with any other discharges of pollutants to that waterbody (be it from other
point sources, non-point source runoff, air deposition, etc.). Given this situation, it is
not clear what would be measured for a numeric limit or when.

- For discharges from the application of pesticides, there are often many short durations,
highly variable, pollutant discharges to surface waters from many different locations for
which it would be difficult to establish a numeric limitation at each location. This
variability makes setting reasonable and fair numeric effluent limitations for pesticide
applications extremely difficult. Even in a normal plant specific setting, EPA takes into
account the variability of pollutant removal performance at a facility operated in
compliance with applicable statutory and regulatory requirements to derive technology-
based limitations. In the water-quality based effluent limitations context, EPA takes
into account ambient conditions of the waterbody which can require complex
modelling and formulas to derive what discharge of pollutant level is necessary,
without being overly stringent, to protect water quality. In the context of pesticide

4 See also; Northwest Envtl. Advocates v. City of Portland, 56 F.3d 979, 988 (9th Cir. 1995) (finding that a narrative
effluent limitation was an enforceable condition of an NPDES permit).

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

application, the numbers of variables that would affect such a calculation becomes
unworkable. In this situation, requiring the use of standard control practices {i.e.,
narrative non-numeric effluent limitations), provides a reasonable approach to control
pesticide discharges of pollutants.

- The precise location for which a numeric effluent limitation would apply is not clear.
Discharges from the application of pesticides are different from discharges of pollutants
of process wastewater from a particular industrial or commercial facility where the
effluent is more predictable and easily identified as an effluent from a conveyance {e.g.,
pipe or ditch), can be precisely measured for compliance prior to discharge, and can be
more effectively analyzed to develop numeric effluent limitations.

- EPA does not have sufficient information to develop numeric effluent limitations. To
develop numeric technology-based effluent limitations, EPA must evaluate factors
outlined in 40 CFR 125.3, such as the age of equipment and facilities involved, the
process employed, the potential process changes, and non-water quality environmental
impacts. In addition, EPA estimates that more than 400 pesticide active ingredients
contained in over 3,500 pesticide products may be covered under this permit.

In the context of this general permit, EPA has determined these non-numeric effluent limits
represent the best practicable technology (BPT) for all pollutants, the best conventional pollutant
control technology for conventional pollutants (BCT) and the best available technology
economically achievable (BAT) for toxic and non-conventional pollutants. Technology-based
effluent limitations in this permit are presented specific to each pesticide use pattern to reflect the
variations in procedures and expectations for the use and application of pesticides. These non-
numeric effluent limitations are expected to reduce the point source discharges of pollutants to
waters of the United States, thereby protecting the receiving waters, including to the extent
necessary to meet applicable water quality standards. EPA notes that the PGP uses the term "Pest
Management Measures." Use of the term Pest Management Measures is intended to better
describe the range of pollutant reduction practices that may be employed when applying
pesticides, whether they are structural, non-structural or procedural and includes BMPs as one of
the components.

The BAT/BPT/BCT effluent limitations in this permit are expressed as specific pollution
prevention requirements for minimizing the pollutant levels in the discharge. In the context of
this general permit, these requirements represent the best technologically available and
economically practicable and achievable controls. EPA has determined that the combination of
pollution prevention approaches and structural management practices required by these limits are
the most environmentally sound way to control the point source discharges of biological
pesticides, and chemical pesticides that leave a residue to meet the effluent limitations. Pollution
prevention continues to be the cornerstone of the NPDES program.

Requirements are technologically available

EPA has found that the requirements of this permit represent the appropriate level of
control representing BPT, BCT, and BAT. The PGP requires certain Operators to implement Pest
Management Measures to meet the technology-based effluent limitations that are based on

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

(Integrated Pest Management (IPM) principles. See further discussion of pest management
measures below. Unlike other general permits, the technology available to Operators depends on
the type of Operator (e.g., Applicator v. Decision-maker). For this reason, technology-based
effluent limitations vary depending on Operator type. As an example of an effluent limit that
meets BPT and BAT standards, Applicators are required to maintain pesticide application
equipment in proper operating condition, including requirement to calibrate, clean, and repair
such equipment and prevent leaks, spills, or other unintended discharges. This effluent limitation
is not appropriate for Decision-makers that do not apply the pesticide themselves and as such, is
not an effluent limitation for Decision-makers. EPA determined that calibrating, cleaning, and
repairing pesticide application equipment is technologically available and based on EPA's
evaluation of this industry, is currently being implemented by many operators and is a practice
that every operator should be doing when using pesticides, as a way to prevent leaks, spills, and
other unintended discharges, such as over-applying pesticides as a result of poorly maintained
equipment.

Requirements meet the BPT and BAT economic tests set forth in the CWA

There are different economic considerations under BPT, BCT, and BAT. EPA finds that
the limits in the PGP meet the BPT and BAT economic tests. Because the types of controls under
consideration minimize toxic, nonconventional, and conventional pollutants, conventional
pollutants are controlled by the same practices that control toxic and nonconventional pollutants.
Hence, EPA is evaluating effluent limits using a BPT and a BAT standard, but since
conventional pollutants will also be adequately controlled by these same effluent limits for which
EPA applied the BPT and BAT tests, EPA has determined that it is not necessary to conduct
BCT economic tests.

Under BPT, EPA has determined that the requirements of this PGP are economically
practicable since they contain the same requirements as found in the previously issued PGPs. To
make the original BPT determination, EPA considered the reasonableness of the relationship
between the costs of application of technology in relation to the effluent reduction benefit
derived. CWA section 301(b)(1)(B); 40 CFR 125.3(d)(1). This analysis was documented in the
fact sheet accompanying the 2011 PGP (available at Regulations.gov in Document ID EPA-HQ-
OW-2010-0257-1276). EPA estimates that the draft 2026 PGP will cover approximately 14,300
Operators. In light of the original BPT determination and the fact that the draft 2026 PGP does
not alter per entity compliance costs, EPA finds that the BPT limits have a cost that is justified
by the effluent reduction resulting from the BPT effluent limitations and that for BAT, the costs
are economically achievable because they can reasonably be borne by the industry as a whole.

EPA continues to study the efficacy of various types of pollution prevention measures and
BMPs; however, for this permit numeric limitations are still not feasible.

Requirements have acceptable non-water quality environmental impacts.

EPA finds that the controls in the permit have acceptable non-water quality environmental
impacts. Because the draft 2026 PGP contains the same requirements as the previously issued
PGPs, there are no significant changes to the non-water quality environmental impacts. EPA also
notes that the requirement to comply with the FIFRA label incorporates the consideration of the

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

environmental impacts of the pesticide's use with the benefits of the pesticide's use. When EPA
determines that a pesticide product can be registered for use, the Agency has concluded that the
use of the pesticide product will not cause unreasonable adverse effects to humans or the
environment when applied according to the label directions and restrictions. "Unreasonable
adverse effects" takes into account the economic, social, and environmental costs and benefits of
the use of the pesticide. EPA finds that the pollutant discharges authorized by this permit have
recreational, environmental or other human benefits. For example, permittees will discharge
pollutants to control for mosquitos and other flying insects in order to prevent the spread of
infectious diseases, such as malaria, vesicular stomatitis, and West Nile Virus. Control of weed,
algae, and plant pathogens promotes healthy aquatic communities and recreational and other
benefits for the human population. Permittees will also discharge pollutants to control invasive
and nuisance aquatic animals, such as fish, lampreys, and mollusks, which negatively affect
aquatic biodiversity, human health, and economic stability. Pollutant discharges will also control
pests that threaten the health of the forest canopy, such as the gypsy moth. This permit includes
permit terms which provide reasonable protection to impacted waters of the United States
without constraining the use of these pesticides which provide acceptable non-water quality
environmental impacts.

Pest Management Measures Used to Meet the Technology-Based Effluent Limitations

Just as there is variability in the pesticide applications as described above, there is
variability in the Pest Management Measures that can be used to meet the effluent limitations.
Therefore, EPA is not mandating the specific Pest Management Measures Operators must
implement to meet the limitations. This is analogous to an industrial situation where discharges
of pollutants to waters of the United States are via pipes and a numeric effluent limitation may be
specified as a given quantity of pollutant that may be discharged, but EPA would not specify
what technology should be employed to meet that limitation. For pesticides, namely
mosquitocides, for example, Part 2.2.1.b of the PGP requires mosquito control Decision-makers
to consider mechanical/physical methods of control to eliminate or reduce mosquito habitat.
How this is achieved will vary by Operator: For some, this may be achieved through elimination
of development habitat (e.g., filling low areas, dredging, etc.) while for others these measures
will not be feasible. Thus, a given Pest Management Measure may be acceptable and appropriate
in some circumstances but not in others. In this respect, the non-numeric effluent limitations in
the PGP are similar to performance-based numeric effluent limitations, which also do not require
specific control technologies as long as the limitations are met.

Pest Management Measures can be actions (including processes, procedures, schedules of
activities, prohibitions on practices, and other management practices), or structural or installed
devices to prevent or reduce water pollution. The key is determining what measure is appropriate
for the situation in order to meet the effluent limitation. In this permit, Operators are required to
implement site-specific Pest Management Measures to meet these effluent limitations. The
permit along with this fact sheet provide examples of Pest Management Measures, but Operators
must tailor these to their situations as well as improve upon them as necessary to meet the
effluent limitations.

The approach to Pest Management Measures in this permit is consistent with the CWA as
well as its implementing regulations at 40 CFR 122.44(k)(4). Section 402(a)(2) of the CWA

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states: "The administrator shall prescribe conditions for such permits to assure compliance with
the requirements in paragraph (1) . . . including conditions on data and information collection,
reporting and such other requirements as he deems appropriate." (Section 402(a)(1) includes
effluent limitation requirements.) This statutory provision is reflected in the CWA implementing
regulations, which state that BMPs (in this case, specifically Pest Management Measures) can be
included in permits when, "[t]he practices are reasonably necessary to achieve effluent
limitations and standards or to carry out the purposes and intent of the CWA." 40 CFR
122.44(k)(4).

Implementation of Pest Management Measures

Part 2.0 of the PGP requires Operators to implement Pest Management Measures to meet
the technology-based effluent limitations listed in that Part. It also provides Operators with
important considerations for the implementation of their specific Pest Management Measures.
Some Decision-makers will have to document how such factors were taken into account in the
implementation of their Pest Management Measures (See Part 5 of the PGP). EPA recognizes
that not all of these considerations will be applicable to every pest management area, nor will
they always affect the choice of Pest Management Measures. EPA expects that Operators have
the experience and working knowledge to apply pesticides properly. The PGP requires the
Operator to apply such expertise and working knowledge to use best professional judgment in
meeting the permit terms. If Operators find their Pest Management Measures are not minimizing
discharges of pollutants adequately, the Pest Management Measures must be modified as
expeditiously as practicable. See Part 6 of the PGP, Corrective Action.

EPA recognizes that Operators need the flexibility to tailor Pest Management Measures to
their situation as well as improve upon them as necessary to meet the technology-based effluent
limitations. Decision-makers will tailor Pest Management Measures based on available
information and the best professional judgment of qualified personnel. For example, while Part
2.2 of the PGP requires Decision-makers to evaluate other means than pesticide use, the
Decision-makers ultimately decide what ultimate pest control method is employed. Thus, while
mechanical pest removal or less toxic chemicals may be possible options, the Decision-maker is
in the best position to know what method is most appropriate and effective against the target
pest.

Pest Management Measures and Technology-Based Effluent Limitations - Definition of
"Minimize"

EPA has found that the requirements of the PGP represent the appropriate BPT, BCT and
BAT level of control. The non-numeric effluent limitations require Operators to "minimize"
discharges of pollutants. Consistent with the control level requirements of the CWA, the term
"minimize" means to reduce and/or eliminate pollutants discharges to waters of the United States
through the use of Pest Management Measures to the extent technologically available and
economically achievable and practicable. For many pesticide applications, minimization of the
discharge of pesticides to waters of the United States can be achieved without using highly
engineered, complex pest control systems. The specific limits included in Part 2.0 of the PGP
emphasize effective "low-tech" approaches, including using only the amount of pesticide product
and frequency of pesticide application necessary to control the target pest, performing equipment

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

maintenance and calibration, assessing weather conditions prior to pesticide application,
accurately identifying the pest problem, efficiently and effectively managing the pest problem,
and properly using pesticides.

Statutes, Regulations, and Other Requirements

In addition to the applicable permit requirements, Operators must comply with all applicable
statutes, regulations and other requirements including, but not limited to, requirements contained
in the labeling of pesticide products approved under FIFRA ("FIFRA labeling"). See Part 1.5 of
the PGP. See also Part 2.0 ("As stated in Part 1.5, this permit requires all Operators to comply
with all other applicable federal or state laws and regulations that pertain to application of
pesticides by the Operator."). Although the FIFRA label and labeling requirements are not
effluent limitations, it is illegal to use a registered pesticide inconsistent with its labeling. In fact,
Operators discharging under EPA's PGP must comply with FIFRA labeling requirements in
order to be in compliance with the PGP technology-based effluent limits. Per Parts 2.1 and 2.2 of
the PGP, "To meet the effluent limitations of this permit, all Applicators [or Decision-makers]
must implement Part 2.1 [or Part 2.2] to minimize the discharge of pesticides to waters of the
United States from the application of pesticides, through the use of Pest Management Measures,
as defined in Appendix A." Per Appendix A, Pest Management Measure means "any practice
used to meet the effluent limitations that comply with manufacturer specifications, industry
standards and recommended industry practices related to the application of pesticides, relevant
legal requirements and other provisions that a prudent Operator would implement to reduce
and/or eliminate pesticide discharges to waters of the United States." Pest Management
Measures include FIFRA labeling requirements. Therefore, if Operators apply a pesticide in a
manner inconsistent with any relevant water-quality related FIFRA labeling requirements such as
those relating to application sites, rates, frequency, and methods, as well as provisions
concerning proper storage and disposal of pesticide wastes and containers, the Operators would
be in violation of the effluent limitation to minimize pesticides entering the waters of the United
States. For example, an Operator, who is a pesticide Applicator, decides to use a mosquito
adulticide pesticide product with a FIFRA label that contains the following language, "Apply this
product at a rate not to exceed one pound per acre." The Applicator applies this product at higher
than the allowable rate, which results in excess product being discharged into waters of the
United States. EPA would find that this application was a misuse of the pesticide under the
FIFRA label. Because of the misuse the Agency might also determine that the effluent limitation
that requires the Operator to minimize discharges of pollutants to waters of the United States was
violated, depending on the specific facts and circumstances. Therefore, pesticide use inconsistent
with certain FIFRA labeling requirements could result in the Operator being held liable for a
CWA violation as well as a FIFRA violation.

Technology-Based Effluent Limitations in the PGP

In the PGP, all Operators are classified as either "Applicators" or "Decision-makers" or
both. An Applicator is an entity who performs the application of a pesticide or who has day-to-
day control of the application (i.e., they are authorized to direct workers to carry out those
activities) that results in a discharge to waters of the United States. A Decision-maker is an entity
with control over the decision to perform pesticide applications, including the ability to modify
those decisions that result in discharges of pollutants to waters of the United States. As such,

39

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more than one Operator may be responsible for compliance with this permit for any single
discharge from the application of pesticides. EPA has delineated the non-numeric effluent
limitations into tasks that EPA expects the Applicator to perform and tasks that EPA expects the
Decision-maker to perform. In doing so, EPA has assigned the Applicator and the Decision-
maker different responsibilities.

2.1 Applicators' Responsibilities

Part 2.1 of the PGP contains the general technology-based effluent limitations that all
Applicators must perform, regardless of pesticide use pattern. These effluent limitations are
generally preventative in nature and are designed to minimize pesticide discharges into waters of
the United States. All Applicators are required to minimize the discharge of pesticides to waters
of the United States by doing the following:

2.1.1 To the extent not determined by the Decision-maker, use only the amount of
pesticide and frequency of pesticide application necessary to control the target
pest, using equipment and application procedures appropriate for this task.

As noted earlier, it is illegal to use a pesticide in any way prohibited by the FIFRA
labeling. Also, use of pesticides must be consistent with any other applicable state or federal
laws. To minimize the total amount of pesticide discharged, Operators must use only the amount
of pesticide and frequency of pesticide application necessary to control the target pest. Using
only the amount of pesticide and frequency of pesticide application needed ensures maximum
efficiency in pest control with the minimum quantity of pesticide. Using only the amount and
frequency of applications necessary can result in cost and time savings to the user. To minimize
discharges of pollutants, Operators should base the rate and frequency of application on what is
known to be effective against the target pest.

2.1.2 Maintain pesticide application equipment in proper operating condition, including
requirement to calibrate, clean, and repair such equipment and prevent leaks,
spills, or other unintended discharges.

Common-sense and good housekeeping practices enable pesticide users to save time and
money and reduce the potential for unintended discharge of pesticides to waters of the United
States. Regular maintenance activities should be practiced and improper pesticide mixing, and
equipment loading should be avoided. When preparing the pesticides for application be certain
that you are mixing them correctly and preparing only the amount of material that you need.
Carefully choose the pesticide mixing and loading area and avoid places where a spill will
discharge into waters of the United States. Some basic practices Operators should consider are:

- Inspect pesticide containers at purchase to ensure proper containment;

- Maintain clean storage facilities for pesticides;

- Regularly monitor containers for leaks;

- Rotate pesticide supplies to prevent leaks that may result from long term storage; and

- Promptly deal with spills following manufacturer recommendations.

To minimize discharges of pollutants, Applicators must ensure that the rate of application
is calibrated {i.e., nozzle choice, droplet size, etc.) to deliver the appropriate quantity of pesticide

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needed to achieve greatest efficacy against the target pest. Improperly calibrated pesticide
equipment may cause either too little or too much pesticide to be applied. This lack of precision
can result in excess pesticide being available or result in ineffective pest control. When done
properly, equipment calibration can assure uniform application to the desired target and result in
higher efficiency in terms of pest control and cost. It is important for Applicators to know that
pesticide application efficiency and precision can be adversely affected by a variety of
mechanical problems that can be addressed through regular calibration. Sound maintenance
practices to consider are:

- Choosing the right spray equipment for the application

- Ensuring proper regulation of pressure and choice of nozzle to ensure desired
application rate

- Calibrating spray equipment prior to use to ensure the rate applied is that required for
effective control of the target pest

- Cleaning all equipment after each use and/or prior to using another pesticide unless a
tank mix is the desired objective and cross contamination is not an issue

- Checking all equipment regularly (e.g., sprayers, hoses, nozzles, etc.) for signs of
uneven wear (e.g., metal fatigue/shavings, cracked hoses, etc.) to prevent equipment
failure that may result in inadvertent discharge into the environment

- Replacing all worn components of pesticide application equipment prior to application.

2.1.3 Assess weather conditions (e.gtemperature, precipitation, and wind speed) in the
treatment area to ensure application is consistent with all applicable federal
requirements.

Weather conditions may affect the results of pesticide application. Applicators must assess
the treatment area to determine whether weather conditions support pest populations and are
suitable for pesticide application.

2.2 Decision-makers' Responsibilities

As noted above, NPDES permits must contain technology-based effluent limitations. Part
2.2 of the PGP contains the effluent limitations that Decision-makers must perform. The PGP
requires all Decision-makers, to the extent Decision-makers determine the amount of pesticide or
frequency of pesticide application, to minimize the discharge of pesticides to waters of the
United States from the application of pesticides, through the use of Pest Management Measures,
as defined in Appendix A of the PGP, by using only the amount of pesticide and frequency of
pesticide application necessary to control the target pest.

In addition, Part 2.2 of the PGP requires that any Decision-maker who is required to submit
a Notice of Intent (NOI) to identify the pest problem, implement effective and efficient pest
management options, and adhere to certain pesticide use provisions. (For purposes of the
discussion below on Part 2.2 of the PGP, the term Decision-maker means any Decision-maker
who is or will be required to submit an NOI.) Parts 2.2.1 - 2.2.4 of the PGP do not apply to
Decision-makers who will need to submit an NOI only because they discharge pollutants to
waters of the United States containing NMFS Listed Resources of Concern and whose: (1)
Pesticide application activities for which permit coverage is being requested will discharge

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pollutants to one or more receiving waters of the United States containing NMFS Listed
Resources of Concern, but consultation with NMFS under Section 7 of the ESA has been
concluded for pesticide application activities covered under this permit; or (2) Pesticide
application activities for which permit coverage is being requested will discharge pollutants to
one or more waters of the United States containing NMFS Listed Resources of Concern, but all
"take" of these resources associated with such pesticide application activities has been authorized
through NMFS' issuance of a permit under Section 10 of the ESA, and such authorization
addresses the effects of the pesticide discharges and discharge-related activities on federally-
listed species and federally-designated critical habitat. However, these Decision-makers must
comply with all applicable conditions and/or requirements resulting from ESA Section 7
consultation or ESA Section 10 permit. NOTE: EPA is proposing the same ESA procedures for
FWS under the draft 2026 PGP as described above for NMFS. Decision-makers must also
comply with all applicable conditions and/or requirements resulting from ESA Section 7
consultation or ESA Section 10 permit for discharge pollutants to one or more waters of the
United States containing FWS Listed Resources of Concern.

Decision-makers are required to perform each of these permit conditions prior to the first
pesticide application covered under this permit and at least once each calendar year thereafter.
These additional technology-based effluent limitations are based on integrated pest management
principles. EPA is requiring certain Decision-makers to also comply with a different technology-
based effluent limitation than Applicators because the Agency has determined that they are the
Best Available Technology Economically Achievable for these Operators. These requirements
are aimed at reducing discharge of pesticides to waters of the United States and lessening the
adverse effects of pesticides that are applied. Each pesticide use pattern has specific limitations,
and these requirements are divided into three different sections: (1) identify the problem, (2) pest
management options, and (3) pesticide use. For each pest management area, Decision-makers
must identify the problem prior to pesticide application, consider using a combination of
chemicals and non-chemical Pest Management Measures, and perform surveillance before
pesticide application to reduce environmental impacts.

EPA is requiring these additional technology-based effluent limitation requirements from
Decision-makers and not the Applicators because the measures necessary to meet these
requirements are within the control of the Decision-makers, not the Applicators.

As stated above, these technology-based effluent limitations are based on integrated pest
management principles. Integrated pest management, as defined in FIFRA, is a sustainable
approach to managing pests by combining biological, cultural, physical, and chemical tools in a
way that minimizes economic, health, and environmental risks. (FIFRA, 7 U.S.C. 136r-1)
Integrated pest management is not a single pest control method but, rather, a series of pest
management evaluations, decisions and controls. In evaluating available and relevant
information, EPA found that some commercial (For-Hire Applicators) and non-commercial (e.g.,
state governments, federal governments, local governments, utilities) entities are currently
implementing integrated pest management or components of integrated pest management to
minimize pesticide use. For example, federal agencies are required to implement integrated pest
management under 7 USC 136r-1, "Federal agencies shall use Integrated Pest Management
techniques in carrying out pest management through procurement and regulatory policies, and

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other activities." In addition, Executive Order 13514 (October 5, 2009) requires the head of each
federal agency to implement integrated pest management and other appropriate landscape
management practices as a means to promote pollution prevention and eliminate waste.

Below is a general discussion describing the limitations for all pesticide use patterns.
Following the general discussion are more detailed descriptions of each specific requirement
under each pesticide use pattern.

Any Decision-maker who is or will be required to submit an NOI must do the following
regardless of the pesticide use pattern, except those Decision-makers who will need to submit an
NOI only because they discharge pollutants to waters of the United States containing NMFS
Listed Resources of Concern and that also comply with provisions in Part 1.6 of the PGP:

Identify the Problem

Decision-makers are required to identify the pest problem, identify the target pest, and
establish an action threshold. Understanding the pest biology and ecology will provide insight
into selecting the most effective and efficient Pest Management Measures (pesticidal or non-
pesticidal methods), and in developing an action threshold. Action threshold is defined in
Appendix A of the PGP as the point at which pest populations or environmental conditions
cannot be tolerated, necessitating that pest control action be taken based on economic, human
health, aesthetic, or other effects. An action threshold helps determine both the need for control
actions and the proper timing of such actions. It is a predetermined pest level that is deemed to
be unacceptable. In some situations, the action threshold for a pest may be zero {i.e., no presence
of the pest is tolerated). This is especially true when the pest is capable of transmitting a human
pathogen {e.g., mosquitoes and the West Nile virus) and/or is an invasive species. In areas where
aquatic weeds are problematic, it may be preferable to use an aquatic herbicide as a preventive
measure rather than after weeds become established. In some situations, even a slight amount of
pest damage may be unacceptable for ecological or aesthetic reasons. Sometimes pre-emergent
pesticide application is needed, as a preventive measure to keep aquatic weeds at bay. Action
thresholds, often expressed as number of pests per unit area, can vary by pest, by site, and by
season. In a new pest management program, action thresholds may be difficult to establish and as
a practical approach should first focus on major pests. As Operators gain insight and experience
into specific pest management settings, the action levels can be revised up or down.

To identify the problem at a treatment area, Decision-makers may use existing data to meet
the conditions of this permit. For example, a mosquito district may use surveillance data from an
adjacent district to identify pests in their pest management area. Decision-makers may also use
relevant historical site data.

Pest Management Options

Decision-makers are required to implement efficient and effective means of Pest
Management Measures that most successfully minimize discharges of pollutants to waters of the
United States resulting from the application of pesticides. Decision-makers must evaluate both
pesticide and non-pesticide methods. Decision-makers must consider and evaluate the following
options: no action, prevention, mechanical/physical methods, cultural methods, biological
control agents, and pesticides. In the evaluation of these options, Decision-makers must consider

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impacts to water quality, impacts to non-target organisms, feasibility, and cost effectiveness.
Combinations of various management options are frequently the most effective Pest
Management Measures over the long term. The goal should be to emphasize long-term control
rather than a temporary fix. For additional information, see discussion under each pesticide use
pattern.

Pesticide Use

Decision-makers are required to conduct pest surveillance in an area that is representative
of the pest problem and reduce the impact on the environment. Pest surveillance is important to
properly time the need for pest control. To reduce the impact on the environment and non-target
organisms, Operators are required to only apply pesticides when the action threshold has been
met. As noted earlier, action thresholds help determine both the need for control actions and the
proper timing of such actions.

There are additional requirements designed for each pesticide use pattern in Parts 2.2.1
through 2.2.4 of the PGP. For additional information and other limits on pesticide use, see
specific discussion under each pesticide use pattern.

2.2.1 Mosquito and Other Flying Insect Pests Control

Part 2.2.1.a ~ Identify the Problem

Establish densities for larval and adult mosquito or flying insect pest populations or
identify environmental condition(s), either current or based on historical data, to serve as
action threshold(s) for implementing Pest Management Measures. Decision-makers must
develop action thresholds for larval and adult mosquitoes prior to the first pesticide application
covered under this permit. The action thresholds must be re-evaluated at least once each calendar
year. As noted in the general discussion above, an action threshold is a point at which pest
populations or environmental conditions indicate that pest control action must be taken. Action
thresholds help determine both the need for control actions and the proper timing of such actions.
For example, an action threshold could be the number and distribution of service requests
received from the public. It is a predetermined pest level (or other indicator) that is deemed to be
unacceptable. For example, in Maryland, "A collection of more than 10 anthropophagous
(human biting) female mosquitoes per night of trap operation is considered to be the level which
causes discomfort and/or complaints from the majority of people. The light trap action threshold

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for ground spraying of adult mosquitoes is 10-20 per trap-night. The action threshold to suppress
pest populations of adult mosquitoes by aerial spraying (application of insecticide by an aircraft)
is a light trap collection of 100 female mosquitoes. The action threshold for landing rate counts
to justify ground spraying for the control of adult mosquitoes is 3 mosquitoes in 2 minutes. The
action threshold for aerial spraying is 12 mosquitoes per minute."5 For larvae control, action
thresholds are determined by standard mosquito dipping techniques. For example, in Canyon
County Mosquito Abatement District, Idaho6, they established larvae density action levels for
Culex species (primary disease vectors) as Low: 1-5 larvae per dip; Medium: 6-10 larvae per dip;
High: > than 10 larvae per dip. The larvae density action threshold can be used to determine how
much larval control products are to be used or even if any action is to be taken. In some
situations, the action threshold for a pest may be zero {i.e., no presence of the pest is tolerated).
This is especially true when the pest is capable of transmitting a human pathogen {e.g.,
mosquitoes and the West Nile virus).

Identify the target pest(s) to develop Pest Management Measures based on
developmental and behavioral considerations for each pest. Knowledge of the developmental
biology of mosquitoes is essential to developing Pest Management Measures for mosquito
control.

Prior to the first pesticide application covered under the permit, Operators must ensure
proper identification of mosquito to better understand the biology of the target pest and develop
Pest Management Measures. Due to the great variability in developmental habitats and adult
feeding behaviors as discussed previously, proper identification is imperative in designing an
effective and efficient Pest Management Measures. Identification of the target pest will aid in
development of Pest Management Measures aimed at both the immature and adult
developmental stages. Identification of the target pest for a specific area allows 1) identification
of potential breeding sites, 2) evaluation of alternative Pest Management Measures aimed at
controlling the immature stages (habitat modification, source reduction, larvicides, biological
larvicides, and oils), and 3) assessment of potential for disease transmission.

Similarly, for black flies, prior to first pesticide application covered under this permit,
Operators must ensure proper identification of the pest to develop Pest Management Measures.
Due to preferred hosts and developmental habitats, proper identification of the pest is
instrumental in determining the biology (univoltine or multivoltine), and developmental habitat
preference {e.g., flow rate, stream size, stream substrate composition), and flight range of the
target pest. By knowing these factors, a control program can 1) determine if the black fly species
warrants control activities {i.e. host preference and historical problems), 2) identify habitats and
delineate the potential area for ongoing monitoring and control activities, 3) determine frequency
of site monitoring, 4) estimate timing for pesticide application {i.e. historical seasonal
occurrence, age distribution of susceptible immature population, environmental conditions
suitable for control activity, etc.), 5) reduce discharge of pesticides into waters of the United
States.

5 http://mda.marvland.gov/plants-pests/Pages/mosauito control program descriptionaspx

6 http://www.canvoncountvmosauito.com/CCMADMosauitoPesticideUsePlan.pdf

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Identify known breeding sites for source reduction, larval control program, and
habitat management. Once pests have been identified, mapping is a valuable tool in assessing
mosquito habitats and designing control programs for a specific area to minimize pesticide
discharges into waters of the United States. Maps may simply be township/city/county maps but
may also include aerial photo assessments, topographic maps, and satellite imagery where
available and/practicable. Mapping is essential to identify pest producing areas which can and
cannot be controlled using non-chemical preventative measures (e.g., source reduction). Maps
should include all potential sites for mosquito development including agricultural areas in the
specific area (e.g., hay, pasture, circle irrigation, orchards, rill irrigated field crops, and flood
irrigated pastures and farmland). Mapping should also be a priority in a surveillance program
utilizing mosquito traps, biting counts, complaints, and reports from the public. Planning in
coordination with mapping ensures the best Pest Management Measures (whether source
reduction, biological, or chemical) for each particular pest is chosen. Operators must identify
known breeding sites prior to the first pesticide application covered under this permit.

In conjunction with identifying the target pest, mapping should be considered part of
control programs aimed at black fly management. As black flies are strong fliers and will travel
great distance to obtain a blood meal, mapping should be for an extended area from the site to be
protected by control activities. Pest identification and mapping should also be a priority in a
surveillance program (both current and historical) to determine the need for initiating control
activity. Identification and mapping are both essential to planning a control program which
reduces pesticide discharges into waters of the United States.

Analyze existing surveillance data to identify new or unidentified sources of mosquito
or flying insect pest problems as well as sites that have recurring pest problems. As

discussed above, mapping is a valuable tool in assessing mosquito habitats and designing control
programs. Decision-makers must analyze existing surveillance data to identity any new source of
pest problems.

In the event there are no data for the pest management area in the past calendar year,
use other available data as appropriate to meet the permit conditions in Part 2.2.1.a.

Decision-makers may use historical data or neighboring district data to identify the pest and
establish action thresholds.

Part 2.2.1.b — Pest Management Options

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management options and implement Pest Management Measures to minimize pesticide
discharges into waters of the United States prior to the first pesticide application covered under
this permit. For black flies, Pest Management Measures will vary by locality {i.e., stream size,
stream substrate, and stream vegetation), black fly species (5 multi/univoltine development and
host specificity), and financial concerns {i.e., accessibility to streams and size/rate of flow for the
streams). As noted above, combinations of various management options are frequently the most
effective Pest Management Measures over the long term. The goal should be to emphasize long-
term control rather than a temporary fix. Decision-makers must reevaluate every year prior to the
first pesticide application for that calendar year.

Based on problem identification, two preventive measures other than pesticides should be
evaluated for black flies. The first is reducing the number of black fly breeding areas. This may
include removal (physical and/or chemical) of vegetation and other objects in streams to reduce
number of larval habitats. The second is temporary damming of flowing stream larval
development sites to create pool habitats. As larvae require flowing water for development,
pooling can kill developing black fly larvae. However, the impact of these habitat management
options must be considered in relation to other environmental impacts on other aquatic species.
Furthermore, due to the wide variability in stream size/flow rate and the accessibility of streams
for habitat modification, these options are seldom acceptable control solutions for most black fly
developmental habitats. The following describes the management options that must be evaluated.
Tactics of preventative, cultural, mechanical/physical, and biological Pest Management
Measures may overlap for some aquatic systems or specific pest control situations.

No Action. No action is to be taken, although a mosquito problem has been identified. This may
be appropriate in cases where, for example, available control methods may cause secondary or
non-target impacts that are not justified, or no control methods exist.

Prevention. Prevention strategies are program activities which eliminate developing mosquito
populations through environmental modification and/or habitat management. For mosquito
control, these activities are physical methods such as habitat modification, cultural methods that
reduce sources of mosquitoes, and biological control.

Mechanical/Physical Methods. Habitat modification, also known as physical or permanent
control, is in many cases the most effective mosquito control technique available and is
accomplished by eliminating mosquito breeding sites. Habitat modification activities have the
potential to be both effective and economical in some areas and can virtually eliminate the need
for pesticide use in and adjacent to the affected habitat. However, the ability to use prevention
strategies is dependent upon local authority and restrictions.

Cultural Methods. Cultural methods can reduce sources of mosquitoes and can be as simple as
properly discarding old containers that hold water capable of producing Aedes aegypti, Ae.
albopictus or Culex spp. or as complex as implementing Rotational Impoundment Management
(RIM) or Open Marsh Water Management (OMWM) techniques. RIM is a source reduction
strategy that controls salt marsh mosquitoes {e.g., Ae. taeniorhynchus and Ae. sollicitans) at the
same time as significant habitat restoration is occurring. Source reduction may include: water
management, vegetation management, biological control, and pesticide use in non-waters of the
United States.

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Containers provide excellent habitats for development of numerous mosquito species.

These may include but are not limited to flowerpots, cans, and tires. Container-inhabiting
mosquitoes of particular concern include, Ae. aeypti, Ae. albopictus, Cx. p. pipiens, and Cx.
salinarious. A container-breeding mosquito problem can be solved by properly disposing of such
materials, covering them, tipping them over to ensure that they do not collect water, and/or
periodic draining. Urban container-breeding mosquito control is best implemented through
education and surveillance programs.

Source reduction in freshwater lakes, ponds, and retention areas is more applicable to
artificially created areas than natural areas. Artificial ponds can be eliminated as a breeding site
simply by filling in the areas, {i.e., habitat modification). However, large permanent water bodies
and areas for stormwater or wastewater retention require other methods. Options for these areas
include minimizing and/or eliminating emergent and standing vegetation, maintenance of steep
banks, and inclusion of deep-water areas as sanctuary for larvivorous fish.

Mosquito production from stormwater/wastewater habitats can result in considerable
mosquito problems as a result of engineering, poor construction or improper maintenance.
However, mosquito populations can typically be managed by keeping such areas free of weeds
through an aquatic plant management program and maintaining water quality that can support
larvivorous fish. Culex, Coquillettidia, Mansonia, and Anopheles mosquitoes are often produced
in these habitats.

Pastures and agricultural lands are enormous mosquito producers, frequently generating
huge broods of Aedes, Psorophora, and Culex mosquitoes. Improved drainage is one effective
tool for source reduction in such habitats. The second is the use of efficient, precision irrigation
practices that will result in less standing water for those agricultural areas that require artificial
watering.

In coastal areas with extensive coastal salt marshes, there can be tremendous production of
Aedes mosquitoes, making coastal human habitation virtually impossible. Several source
reduction efforts can greatly reduce salt-marsh mosquito production through high-to mid-
intensity management that relies upon artificial manipulation of the frequency and duration of
inundation.

Biological Control Agents. The use of biological organisms or their byproducts to combat pest
insects, such as mosquitoes, is termed biological control, or biocontrol. Biocontrol is utilization
of parasites, predators, and pathogens to regulate pest populations. Generally, this definition
includes natural and genetically modified organisms and means that the agent must be alive and
able to attack the mosquito. The overall premise is simple: Biocontrol agents that attack
mosquitoes naturally are grown in the lab and then released into the environment, usually in far
greater numbers than they normally occur, and often in habitats that previously were devoid of
them, so as to control targeted mosquito species.

One advantage of biocontrol agents is host-specificity which affords minimal disturbance
to non-target species and to the environment. However, it is this specificity and the cost of
commercializing biocontrol agents that deter development of biocontrol agents. In addition,

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utilization of biocontrol requires increased capital outlay and start-up costs as well as increased
training requirements for personnel.

Biocontrol should be considered a set of tools that a mosquito control program can use
when it is economically feasible. When combined with conventional chemicals and physical
control procedures, biocontrol agents can provide short and, occasionally, long-term control.
Biocontrol, as a conventional control method, should aim at the weakest link of the life cycle of
the mosquito. In most cases, this is the larval life stage.

Mosquitofish (Gambusia affinis) are currently the most extensively used biocontrol agent.
These fish, which feed on mosquito larvae, can be placed in a variety of permanent and semi-
permanent water habitats. Differences of opinion exist on the utility and actual control benefits
derived from Gambusia implementation in an integrated pest management program with results
reported from excellent control to no control at all. Concerns over placing Gambusia in habitats
where other fish species assemblages are threatened have been ongoing. Care must be taken in
placement of this cosmopolitan species in areas where endemic fish species are sensitive to
further environmental perturbation. Additionally, use of endemic fish species in these areas of
concern deserves greater attention.

In some aquatic habitats, fish function as an excellent mosquito biocontrol mechanism.
These typically are permanent habitats where Culex and Anopheles are the primary mosquito
residents and where the mosquito densities are not excessive. However, in habitats such as salt
marshes fish are unable to control the sudden explosion of larvae produced by rainfall or rising
tides. Here, the mosquito population numerically exceeds what the fish can consume during the
brief immature mosquito developmental period. In salt marshes, fish must rely on things other
than mosquito larvae for their nutritional needs most of the time, simply because there may be
long delays between hatches of larvae. Mosquito larvae present an abundant food source, but
only for a few days during their rapid development.

Species of predacious mosquitoes in the genus Toxorhynchites have been studied in a
variety of urban areas for control of container-inhabiting mosquitoes, such as the Asian tiger
mosquito (Ae. albopictus). Toxorhynchites mosquitoes also affect mosquito populations that
develop in the treehole environment; however, their introduction into urban container habitats
has proven unsuccessful.

In specific containers, Toxorhynchites may consume a large number of prey mosquito
larvae, such as Aedes aegypti and Ae. albopictus. However, this predator does not disperse well
enough to impact the vast number of natural and artificial containers used by these mosquitoes.
Additionally, their life-cycle is two to three times that of their prey making it impossible for
them to keep up with the other more rapidly developing mosquitoes.

Another group of biocontrol agents with promise for mosquito control is the predacious
copepods (very small crustaceans). Copepods can be readily mass reared, are easily to delivered
to the target sites, and perform well when used with insecticides.

Birds and bats are often promoted as potential biocontrol agents of adult mosquitoes.
However, while both predators eat adult mosquitoes, they do not do so in sufficient amounts to
impact the mosquito populations. Mosquitoes provide such a small amount of nutrition that birds

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or bats expel more energy pursuing and eating mosquitoes than they derive from them. They are
not a primary food source for these predators. Additionally, with mosquito flight behavior being
crepuscular they are not active during the feeding periods of most birds. While bats are active
during the correct time period, they simply cannot impact the massive numbers of adult
mosquitoes available.

Bio-rational products exploit insecticidal toxins found in certain naturally occurring
bacteria. These bacteria are cultured in mass and packaged in various formulations. The bacteria
must be ingested by mosquito larvae, so the toxin is released. Therefore bio-rational products are
only effective against larvae since pupae do not feed. The bacteria used to control mosquito
larvae have no significant effects on non-target organisms. The possibility of creating a new
invasive species by the introduction of biocontrols should be considered, evaluated, and avoided.

Pesticides. There are chemical and biological pesticide products registered for use against
mosquitoes. Two biological pesticide products that are used against mosquito larvae singly or in
combination are Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (Bs).
Manufactured Bti contains dead bacteria and remains effective in the water for 24 to 48 hours;
some slow release formulations provide longer control. In contrast, Bs products contain live
bacteria that in favorable conditions remain effective for more than 30 days. Both products are
safe enough to be used in water that is consumed by humans. In addition to the biological
pesticides, there are chemical pesticides for use against mosquitoes. As described below, once
the determination is made to use pesticides to control mosquitoes, additional requirements under
the PGP must be met.

Part 2.2.1.c. — Pesticide Use

Conduct larval and/or adult surveillance in an area that is representative of the pest
problem or evaluate existing larval surveillance data, environmental conditions, or data
from adjacent area prior to each pesticide application to assess the pest management area
and to determine when action threshold(s) is met. Pest surveillance is important for timing
pest control properly and to evaluate the potential need for pesticide use for mosquito control.
Understanding surveillance data may enable mosquito control Operators to more effectively
target their control efforts. Decision-makers are required to conduct a surveillance program to
minimize discharges of pollutants from control activities. Surveillance is necessary not only to
establish pests' presence and abundance but also as an evaluation tool of the effectiveness of
source reduction and chemical control activities. Furthermore, surveillance should be used as an
indicator of the need for additional chemical control activities based on pre-established criteria
related to population densities in local areas.

Larval surveillance involves routine sampling of aquatic habitats for developing
mosquitoes. The primary tools used to determine larval densities and species composition are a
calibrated dip cup and/or a bulb syringe for inaccessible areas such as treeholes. The counts may
be expressed as the number of immature (larvae and pupae) mosquitoes per dip, per unit volume,
or per unit surface area of the site. However, due to natural mortality from environmental factors,
disease and predators, larval dip counts do not provide an accurate indication of the potential
adult population. Nevertheless, larval counts do indicate when chemical larval control measures
are warranted.

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Adult surveillance is a key component of Pest Management Measures. Adult surveillance
can be conducted using a variety of methods including but not limited to CDC traps, New Jersey
light traps, resting site traps, egg oviposition traps, vehicle traps, and landing count rates.
Mosquito control Operators should use a variety of the available traps as adults are attracted to
different traps depending on their species, sex, and physiological condition. Trapped adults
provide information about local species composition, distribution, and density. In addition, the
need for adulticide application may also be established through the number and distribution of
service requests received from the public. Collection data also provide feedback to the mapping
and planning component of the integrated pest management program as well as to its
effectiveness and also serve to identify new sources of mosquitoes or identify recurring problem
sites.

Disease surveillance, where practical, is also a key component of Pest Management
Measures. Detecting antibodies in "sentinel" chicken flocks, equine cases, and testing dead birds
and adult mosquitoes for infections are all used to determine whether disease is being transmitted
in an area. Mosquito and vector control agencies also may test mosquitoes for viruses in their
laboratories. Although generally less sensitive than sentinel chickens, mosquito infections may
be detected earlier in the season than chicken seroconversions and therefore provide an early
warning of virus activity. However, disease surveillance is not applicable to all mosquito control
programs. In the absence of a dedicated disease surveillance program, mosquito control
Operators should stay informed of arboviral occurrence or potential for occurrence in their
control areas as determined by local, state, and/or national public health agencies.

Larval surveillance involves routine sampling of aquatic habitats for developing black flies.
Larval surveillance is primarily accomplished by collecting stream substrates (rocks, vegetation,
etc.) and examining for larval and pupal occurrence. Due to the varied developmental sites for
black larvae and their ability to move in streams relative to changes in flow patterns, quantitative
sampling will vary from site to site and in many instances, particularly with continuously
changing water levels, is not practical. Qualitative sampling is often used in lieu of quantitative
sampling, as an indicator of egg hatch and to indicate the age distribution of developing larvae.
Qualitative sampling alone when used in conjunction with historical occurrence data can provide
a reliable indicator of the need to initiate control activities.

Adult surveillance for black flies may include sweep sampling, vacuum aspiration of
adults, and the use of silhouette traps. Traps may be simple visual attractants or may be baited
with artificial attractants (e.g., ocentol and CO2). However, as different black fly species will
respond differently in relation to different attractants, based on host preference, care must be
used in selecting attractants that will provide a representative sample of the complete black fly
spectrum present in any given location. Choice of adult sampling will in many cases be dictated
by historical occurrence of black flies in a given area. Regardless, surveillance data is a useful
tool in providing feedback to the mapping and planning component of any Pest Management
Measure.

Aside from surveillance data, Decision-makers may also evaluate environmental conditions
to assess the pest management area. For example, if the pest management area is known for pest
development after flooding then Pest Management Measures may be needed after a rainstorm.

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Reduce the impact on the environment and on non-target organisms by applying the
pesticide only when the action threshold(s) has been met. Operators must apply pesticide only
as indicated by action thresholds for the pest management area. As noted above, action
thresholds, established by the Decision-maker, help determine both the need for control actions
and the proper timing of such actions. Timing pesticide application can reduce the impact on the
environment and on non-target organisms.

In situations or locations where practicable and feasible for efficacious control, use
larvicides as a preferred pesticide for mosquito or flying insect pest control when the larval
action threshold(s) has been met. Operators may use larvicides, adulticides or a combination of
both. However, when practicable and feasible, larviciding should be the primary method for
mosquito control. Larviciding is a general term for the process of killing mosquitoes by applying
natural agents or manmade pesticide products designed to control larvae and pupae (collectively
called larvicides) to aquatic habitats. Larviciding uses a variety of equipment, including aerial,
from boats, and on the ground, as necessitated by the wide range of breeding habitats, target
species, and budgetary constraints. Applications can be made using high pressure sprayers, ULV
sprayers, handheld sprayers, and back sprayers. However, larviciding is only effective when a
high percentage of the mosquito production sites are regularly treated, which may be difficult
and expensive.

There are advantages and disadvantages to aerial and ground larvicide applications. Ground
larviciding allows application to the actual treatment area and consequently to only those micro-
habitats where larvae are present. Therefore, ground larviciding reduces unnecessary pesticide
load on the environment. However, ground applications often rely on in-the-field human
estimates of the size of treatment areas and equipment output with a greater chance of
overdosing or under-dosing. Ground larviciding is also impractical for large or densely wooded
areas and exposes Applicators to greater risk of insecticide exposure.

Aerial larviciding application methods are generally used for controlling mosquito larvae
present in large areas and areas that are inaccessible for ground application. However, failure to
treat an entire area with good larvicide coverage can result in the emergence of large adult
populations. In order to prevent poor site coverage, a global positioning system (GPS), where
economically feasible, or site flagging are necessary to increase accuracy of the pesticide
application coverage while minimizing the amount of larvicides being applied. Aerial application
does provide easier calibration of equipment due to the fact that the target area is generally
mapped, and the material is weighed or measured when loading. However, cost of aerial
application is higher than ground application {i.e., additional personnel for flagging or expensive
electronic guidance systems) and also requires special FAA licenses, training of staff, and
additional liability insurance. In addition, aerial larviciding has greater potential for non-target
impacts.

Bacillus thuringiensis var israelensis (Bti) is the primary larvicide used for black fly control
in the United States. Bti is a gram positive, aerobic, spore-forming bacterium that produces
protoxins in the form of parasporal protein crystals. In the alkaline digestive tract of black flies
and mosquitoes, the protoxins become activated into highly toxic delta-endotoxins. The
endotoxins cause a rapid breakdown in the lining of the mid-gut and necrosis of skeletal muscles,

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resulting in paralysis and mortality of target insect pests. Bti is nontoxic to most non-target
organisms due to their acidic digestive systems and lack of suitable tissue receptor sites.

To minimize pesticide discharges into waters of the United States, Operators must apply
larvicides as needed for source reduction as indicated by the action threshold in situations or
locations where it is practicable and feasible to do so. The action threshold may be based on
occurrence of adults (current or historical) and/or larval sampling of stream substrates for
immature black flies. Surveillance is also a valuable tool for assessing the effectiveness of larval
control activities.

Larvicides may be applied to streams using either ground or aerial equipment. Choice of
equipment is largely dictated by stream size and accessibility. Application equipment may
include backpack sprayers, boats equipped with sprayers or metered release systems, helicopters
or fixed wing aircraft. The amount of insecticide required to treat a stream should be based on
the desired dosage and the stream discharge. Stream discharge is calculated by determining the
average width and depth of the stream and the stream velocity (discharge = width (m) x depth
(m) x velocity (m/s)). Proper calibration of insecticide delivery based on discharge is necessary
to ensure complete coverage throughout the water column in order to expose all larval habitats to
an effective insecticide dose.

A larvicide is applied across the stream width for the time specified by the application rate.
The point of application should be far enough upstream from the larval habitat to ensure proper
insecticide dispersal in the water passing over the treatment area. Operators should determine the
effective downstream carry (maximum distance at which at least 80% larval control is achieved)
of the insecticide suspension. By determining downstream carry, black fly control Operators can
limit the number of applications necessary to treat any given stream and thereby reduce pesticide
discharges into waters of the United States.

In situations or locations where larvicide use is not practicable or feasible for
efficacious control, use adulticides for mosquito or flying insect pest control when the adult
action threshold(s) has been met. Chemical pesticide applications for adult mosquitoes,
adulticiding, is the most visible and commonly used form of mosquito control. Adulticide
applications may be used for nuisance or disease vectoring mosquitoes. Adulticiding consists of
dispersing an insecticide as a space spray into the air column, using ground or aerial equipment,
which then remains suspended in the air column through the habitat where adult mosquitoes are
flying. Any mosquito adulticiding activity that does not follow reasonable guidelines, including
timing of applications, avoidance of sensitive areas, and strict adherence to the pesticide label,
risks affecting non-target insect species.

Operators must ensure that the adulticide applications are made only when necessary by
determining a need in accordance with specific criteria that demonstrate a potential for a
mosquito-borne disease outbreak, or numbers of disease vector mosquitoes sufficient for disease
transmission, or a quantifiable increase in numbers of pestiferous mosquitoes. To determine the
need for adulticide application, at least one of the following criteria should be met and
documented by records: 1) when a large population of adult mosquitoes is demonstrated by
either a quantifiable increase in, or a sustained elevated mosquito population level as detected by
standard surveillance methods, 2) where adult mosquito populations build to levels exceeding

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community standards (e.g., 25 mosquitoes per trap night or 5 mosquitoes per trap hour during
crepuscular periods), and/or 3) when service requests for arthropod control from the public have
been confirmed by one or more recognized surveillance methods.

The most common forms of adulticiding are ultra-low volume spray (ULV) and thermal
fogging. Ground adulticiding is almost exclusively conducted with ULV equipment and is the
most common method used to control mosquitoes. Ground adulticiding can be a very effective
technique for controlling most mosquito species in residential areas with negligible non-target
effects.

Aerial adulticiding is a very effective means of controlling adult mosquitoes, particularly in
inaccessible areas, and may be the only means of covering a very large area quickly in case of
severe mosquito outbreaks or vector borne disease epidemics. Aerial adulticide applications are
made using either fixed wing aircraft or rotor craft. Application is generally as ULV spray, but
some thermal fogging still occurs.

Adulticide application has its own set of conditions that determine success or failure. The
application must be at a dosage rate that is lethal to the target insect and applied with the correct
droplet size. Whether the pesticide application is ground or aerially applied, it must distribute
sufficient insecticide to cover the prescribed area with an effective dose. Typically, with ground
applications, vegetated habitats may require up to three times the dosage rates that open areas
require. This is purely a function of wind movement and its ability to sufficiently carry droplets
to penetrate foliage. In addition, aerial application is dependent upon favorable weather
conditions.

Environmental conditions may also affect the results of adulticide application. Wind
determines how the ULV droplets will be moved from the output into the treatment area.
Conditions of no wind will result in the material not moving from the application point. High
wind, a condition that inhibits mosquito activity, will quickly disperse the insecticide over too
wide an area but at a diluted rate too low to effectively control pests. Light wind conditions (<10
mph) are the most desirable because they move the material through the treatment area and are
less inhibiting to mosquito activity. Thermal fogs perform best under very light wind conditions.

ULV application should be avoided during hot daylight hours. Thermal conditions,
particularly temperature inversion, will cause the small droplets to quickly rise, moving them
away from mosquito habitats. Generally, applications are made after sunset and before sunrise,
depending upon mosquito species activity. Some mosquitoes (Culex and Anopheles) are most
active several hours after sunset, while others (Ae. aegypti and Ae. albopictus) are more active
during the daytime, and if these species are the targets, application should be made during the
period of highest activity for the target species, provided that meteorological conditions are
suitable for application (seldom during daylight hours).

One notable exception to applications made when mosquitoes are up and flying is a
residual barrier treatment application. Barrier applications are based on the natural history and
behavioral characteristics of the mosquito species causing the problem. Barrier applications use a
residual material and are generally applied with a powered backpack sprayer to preferred resting
areas and migratory stops in order to intercept adult mosquitoes hunting for blood meals. Barrier

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applications are often applied during daylight hours as a large-droplet liquid application and are
designed to prevent a rapid re-infestation of specific areas, such as recreational areas, parks,
special-event areas, and private residences. Barrier applications can help provide control of
nuisance mosquitoes for up to one week or longer.

Pesticide control of black flies in the United States historically relied upon both larvicides
and adulticides. However, adulticide use against black fly populations is no longer a common
practice. As adult black flies are seeking blood meals during the daytime, adulticide application
coincides with human activity, so daytime application is no longer a standard control procedure.
One reason for this change is due to environmental factors associated with daytime adulticide
application, particularly thermal inversions, which cause adulticide application for black fly
control to be ineffective. Furthermore, as only adults directly contacted by the adulticide
application are killed, with no residual activity against other adults immigrating to the treatment
area, adulticide applications are both ineffective and expensive. For these reasons, larvicides
which target the immature stages before development of the pestiferous adult are now the
primary means of black fly control in the United States.

For additional information on this pesticide use pattern, see Appendix H of this fact sheet.
2.2.2 Weed and Algae Pest Control

Part 2.2.2.a ~ Identify the Problem

Identify areas with pest problems and characterize the extent of the problems,
including, for example, water use goals not attained (e.g., wildlife habitat, fisheries,
vegetation, and recreation). Decision-makers must be well-acquainted with the unique regional
conditions of their sites and available Pest Management Measures for controlling the pest
present. Intended use goals for the water bodies that are being impeded because of nuisance pest
infestation must also be considered based on the control site. The use of the best available
mapping information to aid in identifying the problem areas is suggested. Mapping may include
aerial photo assessments, topographic maps, and satellite imagery, where available and/or
practicable. Mapping can be essential to identify problem areas which can and cannot be
controlled using non-pesticide preventative measures (e.g., mechanical control). Mapping can
also be used in plotting the regional target pest, as well as water use goals and complaints or
reports of weeds and algae from the public.

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Identify target pest(s). Positive identification of the pest is required because many pests
within the same genera may require different levels and types of Pest Management Measures.
Pest identification is important when determining the best Pest Management Measures for each
pest and for determining application areas. Decision-makers should develop Pest Management
Measures based on identification of the targeted pest which occur in their area.

Identify possible factors causing or contributing to the pest problem (e.g., nutrients,
invasive species, etc.). While there may not be reasonable means to control and/or stop the
introduction and occurrence of some nuisance pest infestations, the identification of possible
sources (e.g., outflows from other water systems/bodies) may help in reducing the need for
pesticide. Potential weed and algae causes, such as changes in nutrient levels or accidental or
intentional introduction of exotic species, must be identified.

Establish any pest- and site-specific action threshold, as defined in Appendix A, for
implementing Part 2.2.2b. Any data and/or information regarding pest can be used to establish
an action threshold. An action threshold must be established.

In the event there are no data for the pest management area in the past calendar year,
use other available data as appropriate to meet the permit conditions in Part 2.2.2.a.

Decision-makers may use historical data or neighboring district data to identify the pest and
establish action thresholds.

Part 2.2.2.b — Pest Management Options

Prior to the first pesticide application covered under this permit that will result in a
discharge to waters of the United States, and at least once each calendar year thereafter
prior to the first pesticide application for that calendar year, any Decision-maker who is or
will be required to submit an NOI must select and implement efficient and effective means
of Pest Management Measures that minimize discharges resulting from the application of
pesticides to control pests. In developing the Pest Management Measures for each pest
management area, the Decision-makers must evaluate the following management options,
including a combination of these management options, considering impact to water quality,
impact to non-target organisms, feasibility, and cost effectiveness: No action; Prevention;
Mechanical/physical methods; Cultural methods; Biological control agents; and Pesticides.
Decision-makers must evaluate management options and implement Pest Management Measures
to minimize pesticide discharges into waters of the United States prior to the first pesticide
application covered under this permit. As noted above, combinations of various management
options are frequently the most effective Pest Management Measures over the long term. The
goal should be to emphasize long-term control rather than a temporary fix. Decision-makers
must reevaluate every year prior to the first pesticide application for that calendar year. All Pest
Management Measures must be implemented in a manner that reduces impacts to non-target
species. The following describes the management options that must be evaluated. Tactics of
preventative, cultural, mechanical/physical, and biological Pest Management Measures may
overlap for some aquatic systems or specific pest control situations.

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No Action

No action is to be taken, although pest problem has been identified. This may be
appropriate in cases where, for example, available pest management options may cause
secondary or non-target impacts that are not justified, no available controls exist, or the pest
population is stable at a level that does not impair water body uses.

Prevention

Preventing introductions of possible pest is the most efficient way to reduce the threat of
nuisance species (ANS Task Force, https://fws.gov/program/aquatic-nuisance-species-task-force).
Identifying primary pathways of introduction and actions to cut off those pathways is essential to
prevention. Through a better understanding of the transportation and introduction of pest, private
entities (aquaculture) and the public have the necessary knowledge to assist in local pest control
by reducing conditions that encourage the spread of pests in their immediate surroundings. For
example, recreational water users provide a pathway of unintentional introductions. Increasing
public awareness of weeds and algae, their impacts, and what individuals can do to prevent their
introduction and spread is critical for prevention. Other examples of prevention include: better
design of water holding sites, better management and maintenance of potential problem sites,
and volunteer removal of pest (e.g., hand weeding). Monitoring and detection also play
important roles in the prevention of the spread and introduction of weeds and algae.

Mechanical or Physical Methods

Mechanical control techniques will vary depending on the pest. Examples include
dewatering, pressure washing, abrasive scrubbing, and weed removal by hand or machine.
Mechanical and biological controls will be the appropriate method in some cases, or a part of a
combination of methods. In some instances, the need for chemical pesticide use in and adjacent
to the affected habitat can be reduced or virtually eliminated with proper execution of Pest
Management Measures.

Cultural Methods

Cultural techniques include the use of pond dyes and water-level drawdown. The use of
certain pond dyes may help manage filamentous algae and submersed (underwater) vegetation.
Several pond colorants and one or two dyes are EPA-registered for weed control. Pond dyes and
colorants can be effective if there is little water outflow from the pond. Dyes and colorants
intercept sunlight needed by algae and other underwater plants for photosynthesis. Therefore,
they are generally ineffective on floating plants like duckweed and water lilies and emergent
(growing above the surface) plants like cattails and bulrushes. Dyes and colorants are nontoxic
and do not kill the plants, and they are safe for use in ponds for irrigation, fishing, and livestock.
However, they are not intended for use in large lakes with a lot of water flow or lakes used for
public water supplies.

Biological Control Agents

Biological control of weeds and algae may be achieved through the introduction of
diseases, predators, or parasites. While biological controls generally have limited application for

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control of weeds and algae, the Operator should fully consider this option in evaluating pest
management options.

Pesticides

Aquatic herbicides are chemicals specifically formulated for use in water to kill or control
aquatic plants. Aquatic herbicides are sprayed directly onto floating or emergent aquatic plants as
well as plants at or near the water's edge or are applied to the water in either a liquid or pellet
form. Systemic herbicides are capable of killing the entire plant. Contact herbicides cause the
parts of the plant in contact with the herbicide to die back, leaving the roots alive and able to
regrow. Non-selective, broad spectrum herbicides will generally affect all plants that they come
in contact with. Selective herbicides will affect only some plants.7

Part 2.2.2.C. — Pesticide Use

Conduct surveillance in an area that is representative of the pest problem prior to
each pesticide application to assess the pest management area and to determine when the
action threshold(s) is met. Often, each weed and algae and pest management area warrant
different Pest Management Measures tailored to regional conditions. The Pest Management
Measures should consist of combinations of mechanical, biological, and/or pesticidal control
methods. All Pest Management Measures must be conducted in a manner that minimizes impacts
to non-target species.

Decision-makers should apply chemical pesticides only after considering the alternatives
and determining those alternatives not to be appropriate Pest Management Measures. Also,
Decision-makers should conduct surveillance (e.g., pest counts or area survey) prior to
application of pesticides to determine when the action threshold is met thus necessitating the
need for implementing Pest Management Measures.

Surveillance may include the relatively sophisticated transect method used in ecological
studies to evaluate species distribution, or it may consist of simply conducting visual
observations in the treated area to verify the eradication or reduction in populations of weeds and
algae following pesticide application (Getsinger et al. 2005, pp 23-25).

Reduce the impact on the environment and non-target organisms by applying the
pesticide only when the action threshold has been met. Operators must apply pesticide only as
indicated by action thresholds for the pest management area. As noted above, action thresholds
help determine both the need to implement Pest Management Measures and the proper timing of
such actions. Timing pesticide application can reduce the impact on the environment and on non-
target organisms.

Environmental factors such as temperature and dissolved oxygen content, as well as
biological factors such as stage of growth, should be considered when deciding on application
timing. Partial site pesticide applications over time may be considered to reduce risk. Pesticide

7 https://www.regulations.gov/document?D=EPA-HO-OW-2015-0499-0Q22
(http://www.ecy.wa.gov/programs/wq/plants/management/aqua028.htmll

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application must be limited to the appropriate amount required to control the target pests.
Methods used in applying pesticides must reduce the impact to non-target species.

For additional information on this pesticide use pattern, see Appendix H of this fact sheet.
2.2.3 Animal Pest Control

Part 2.2.3.a ~ Identify the Problem

The use of the best available mapping information to aid in identifying the problem areas is
suggested. Mapping may include aerial photo assessments, topographic maps, and satellite
imagery where available and/or practicable. Mapping can be essential to identify problem areas
which can and cannot be controlled using non-pesticide preventative measures (e.g., mechanical
control). Mapping can also be used in plotting the regional distribution of desired aquatic
species, as well as water use goals and complaints or reports of pests from the public.

Identify target pest(s). Positive identification of the pest is required because many pests
within the same genus may require different levels and types of Pest Management Measures.
Animal identification is important when determining the best Pest Management Measures for
each particular pest and for determining application areas. Decision-makers must develop Pest
Management Measures based on identification of the targeted pest which occur in their area.

Identify possible factors causing or contributing to the problem (e.g., nutrients,
invasive species). While there may not be reasonable means to control and/or stop the
introduction and occurrence of some pest infestations, the identification of possible sources (e.g.,
outflows from other water systems/bodies) may help in minimizing the need for implementing
Pest Management Measures. Potential factors which could lead to the establishment of animal
populations such as accidental or intentional introduction of exotic species must be identified
before Pest Management Measures are implemented.

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Establish any pest- and site-specific action threshold, as defined in Appendix A, for
implementing Part 2.2.3.b. An action threshold should be established before implementing Pest
Management Measures. Any data and/or information regarding pest can serve as an action
threshold.

In the event there are no data for the pest management area in the past calendar year,
use other available data as appropriate to meet the permit conditions in Part 2.2.3.a.

Decision-makers may use historical data or neighboring district data to identify the pest and
establish action thresholds.

Part 2.2.3.b — Pest Management Options

Prior to the first pesticide application covered under this permit that will result in a
discharge to waters of the United States, and at least once each year thereafter prior to the
first pesticide application during that calendar year, any Decision-maker who is or will be
required to submit an NOI must select and implement efficient and effective means of Pest
Management Measures that minimize discharges resulting from the application of
pesticides to control pests. In developing the Pest Management Measures for each pest
management area, the Decision-maker must evaluate the following management options,
including a combination of management options, considering impact to water quality,
impact to non-target organisms, feasibility, and cost effectiveness: No action; Prevention;
Mechanical/physical methods; Cultural Methods; Biological control agents; and Pesticides.
Decision-makers are required to evaluate management options and implement Pest Management
Measures to minimize pesticide discharges into waters of the United States prior to the first
pesticide application covered under this permit. As noted above, combinations of various
management options are frequently the most effective Pest Management Measures over the long
term. The goal should be to emphasize long-term control rather than a temporary fix. Decision-
makers must reevaluate every year prior to the first pesticide application for that calendar year.
All Pest Management Measures must be conducted in a manner that minimizes impacts to non-
target species. The following describes the management options that must be evaluated. Tactics
of preventative, cultural, mechanical/physical, and biological Pest Management Measures may
overlap for some aquatic systems or specific pest control situations.

No Action

No action is to be taken, although an animal pest problem has been identified. This may be
appropriate in cases where, for example, available control methods may cause secondary or non-
target impacts that are not justified, or no available controls exist.

Prevention

Preventing introductions of possible nuisance species is the most efficient way to reduce
the threat of aquatic nuisance animals (ANS Task Force, 2009). Identifying primary pathways of
introduction and actions to cut off those pathways is essential to prevention. Through a better
understanding of the transportation and introduction of animals, private entities (aquaculturists)
and the public have the necessary knowledge to assist in local animal control by reducing
conditions that encourage the spread of animals in their immediate surroundings. For example,
recreational water users provide a pathway of unintentional introductions. Increasing public

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awareness of pests, their impacts, and what individuals can do to prevent their introduction and
spread is critical for prevention. Other examples of prevention include, better design of water
holding sites, better management and maintenance of potential problem sites, and volunteer
removal of pest species (e.g., fishing). Monitoring and detection also play important roles in the
prevention of the spread and introduction of pests.

Mechanical or Physical Methods

Mechanical and biological controls will be the appropriate methods in some cases of pest
control, or a part of a combination of methods. Mechanical control techniques will vary
depending on the pest. Examples include fishing, dewatering, netting, electrofishing, pressure
washing, use of electric fences, and abrasive scrubbing.

Cultural Methods

Cultural control methods can include physical removal or make the habitat unsuitable for
a pest. Cultural methods vary depending on the target pest and may involve tactics that overlap
with preventative and mechanical methods. Some examples of cultural methods to manage
aquatic animal pests include draining and rinsing boats prior to relocation, using underwater
sounds that deter fish, drawdown of water, and managing vegetation.

Biological Control Agents

Biological control of animals may be achieved through the introduction of diseases,
predators, or parasites. While biological control generally has limited application for control of
animals, Decision-makers should fully consider this option.

Pesticides

Chemical and biological pesticides such as lampricides, molluscides, insecticides, and
piscicides, are registered for use to control animal pests. These pesticides are specifically
formulated for use in water where aquatic nuisance animals occur. In some cases, pesticide use
may impact non-target species. As described below, once the determination is made to use
pesticides, additional requirements must be met.

Part 2.2.3.C. — Pesticide Use

Conduct surveillance in an area that is representative of the pest problem prior to
each application to assess the pest management area and to determine when the action
threshold(s) is met. Often, each animal and pest management area warrant different Pest
Management Measures, tailored to the regional conditions. Pest Management Measures should
consist of combinations of mechanical, biological, and/or pesticidal control methods. All Pest
Management Measures must be conducted in a manner that minimizes impacts to non-target
species.

Operators must apply chemical pesticides only after considering the alternatives and
determining those alternatives not to be appropriate Pest Management Measures. In some
instances, the need for chemical pesticide use in and adjacent to the affected habitat can be
reduced or virtually eliminated with proper execution of alternative strategies and best

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management practices. If pesticides are used, they must only be used as needed as determined by
an action threshold, and Pest Management Measures must be implemented, including use of the
minimum effective application rate. Also, the Decision-maker must conduct surveillance (e.g.,
pest counts or area survey) prior to application of pesticides to determine when the action
threshold is met that necessitates the need for implementing Pest Management Measures.

Surveillance may include the relatively sophisticated transect method used in ecological
studies to evaluate species distribution, or it may consist of simply conducting visual
observations in the treated area to verify the eradication or reduction in populations of aquatic
nuisance animals following pesticide application (Getsinger et al. 2005, pp 23-25).

Reduce the impact on the environment and non-target organisms by evaluating site
restrictions, application timing, and application method in addition to applying the
pesticide only when the action threshold(s) has been met. The pest and site restrictions (water
use, water movement, etc.) must be identified when choosing an appropriate pesticide.
Environmental factors such as temperature as well as biological factors such as migration timing
should be considered when deciding on application timing. Partial site pesticide applications
over time may be considered to minimize risk to non-target organisms.

Pesticide application must be limited to the appropriate amount required to control the
target pests. Methods used in applying pesticides must minimize the impact to non-target
species. For piscicides, chemical deactivation is currently required for all lotic (flowing water)
environments. Management agencies typically work downstream throughout the watershed in
consecutive treatments as this will require the least amount of chemical deactivation. Most
invertebrates repopulate treated areas through immigration (typically in the direction of flow); as
such headwater streams/tributaries seem to be effective at accomplishing this. EPA also notes
that not all piscicides are that harmful to invertebrate populations (e.g., antimycin is more
selective for scaled fish). It can be difficult to know the point at which headwater streams are
"fishless"; however, most fishery management agencies do not treat streams unless they are
considered a refuge for target species.

For additional information on this pesticide use pattern, see Appendix H of this fact sheet.
2.2.4 Forest Canopy Pest Control

Part 2.2.4.a ~ Identify the Problem

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Establish any pest- and site-specific action threshold, as defined in Appendix A, for
implementing Part 2.2.4.b. Decision-makers must develop action thresholds for the target pests
prior to the first pesticide application as covered under the PGP. The action thresholds must be
re-evaluated at least once each calendar year. As noted in the general discussion above, an action
threshold is a point at which pest populations or environmental conditions indicate that Pest
Management Measures must be taken. Action thresholds help determine both the need for
implementing Pest Management Measures and the proper timing of such actions. It is a
predetermined pest level that is deemed to be unacceptable.

Identify target pest(s) to develop Pest Management Measures based on developmental
and behavioral considerations for each pest. Pest identification is a key activity for
implementation of a forest canopy pest control system. Pest identification should only be
conducted by personnel with adequate training and experience with the pests. While numerous
similar pests (insects and/or pathogens) may be present in any given location, only a few of the
representative pest may constitute a threat which requires control activities. Through proper pest
identification informed control decisions can be made based on the development biology of the
pest (susceptible development stage), pest mobility (potential rate of spread), timing of selected
Pest Management Measures, applicable control techniques, and most effective chemical
pesticides for the target pests (insecticide class, resistance, etc.). Failure to identify pests can lead
to unwarranted control activities and/or the need for chemical application with potential for
discharges of pollutants into waters of the United States. Control for each specific pest is also
predicated on the status of the pest as native recurring, quarantine restricted, or designated as an
invasive species.

Identify current distribution of the target pest and assess potential distribution in the
absence of Pest Management Measures. Control activities are warranted only after exact pest
identification and delineation of the extent of the pest infestation. As forest canopy pest control
can involve treating large expanses of forests, mapping is also an important component in
identification of the problem. The distribution of the pest, usually insects, within the area of
infestation can impact the selection of Pest Management Measures. In addition, mapping of the
pest infestation will allow evaluation of the actual/potential spread of the infestation (e.g., pest
biology, pest mobility, and host availability) and also serve as a tool to evaluate the effectiveness
of the Pest Management Measures. Mapping can also provide essential information for
assessment of economic damages that can result from the current and potential pest infestation
and failure to control the pest. Management decisions can thereby be based on cost/benefit
evaluations based on the current and potential distribution of any pest.

The third component of problem identification is to determine the potential economic
impact of not controlling the pest. By establishing economic thresholds, it is possible to
determine pest action thresholds which warrant control activities. However, control decisions
must take into account not only the projected economic impact of the current pest infestation but
also the potential of the pest infestation to spread. Therefore, control decisions based on
economic impact must in turn rely on proper pest identification, pest biology, and current and
potential pest distribution.

In the event there are no data for the pest management area in the past calendar year,
use other available data as appropriate to meet the permit conditions in Part 2.2.4.a.

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Decision-makers may use historical data or neighboring district data to identify the pest and
establish action thresholds.

Part 2.2.4.b. ~ Pest Management Options

Prior to the first pesticide application covered under this permit that will result in a
discharge to waters of the United States, and at least once each calendar year thereafter
prior to the first pesticide application for that calendar year, any Decision-maker who is or
will be required to submit an NOI must select and implement efficient and effective means
of Pest Management Measures that minimize discharges resulting from the application of
pesticides to control pests. In developing the Pest Management Measures for each
management area, the Decision-maker must evaluate the following management options,
including a combination of management options, considering impact to water quality,
impact to non-target organisms, feasibility, and cost effectiveness: No action; Prevention;
Mechanical/physical methods; Cultural methods; Biological control agents; and Pesticides.
Pest control activities in forest canopy management programs may be warranted following
problem identification and based solely on pest occurrence (e.g., quarantine pest, invasive
species). However, in many instances control activities may only be necessary based on pest
population distribution and/or pest densities. To minimize the need for pest control while also
producing the best control results, Pest Management Measures appropriate for the specific
problem site(s) must be developed. A site-specific management plan will consider biotic (e.g.,
plant and animal species community structure) and abiotic (e.g., environmental) factors.
Combinations of various management options are frequently the most effective Pest
Management Measures over the long term. The goal of Pest Management Measures in forest
canopy pest control should be to emphasize long-term control rather than a temporary fix.

All Pest Management Measures must be conducted in a manner that minimizes impacts to
non-target species. The following is a discussion of the relevant management options as they
might be implemented for forest canopy pest control. Tactics of preventative, cultural,
mechanical/physical, and biological Pest Management Measures may overlap for some aquatic
systems or specific pest control situations.

No Action

No action is to be taken, although a pest problem has been identified. This may be
appropriate in cases where available control methods may cause secondary or non-target impacts
or where aesthetic/economic losses are not anticipated.

Mechanical/Physical Methods

Mechanical and biological controls will be the appropriate method in some cases, or a part
of a combination of methods. In some instances, the need for chemical pesticide use in and
adjacent to the affected habitat can be reduced or virtually eliminated with proper execution of
alternative measures and best management practices.

Mechanical control techniques will vary depending on the pest. An example of mechanical
control in a forest canopy would be egg mass removal (e.g., gypsy moth).

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Cultural Methods

Cultural control methods are Pest Management Measures that make the habitat unsuitable
for a pest. An example of a cultural method to manage pests of the forest canopy would be to
select a different species of tree to plant, or to plant resistant varieties of trees. Maintaining the
trees in good health to discourage pests is another method of cultural control.

Biological Control Agents

Biological control of forest canopy pests may be achieved through the
introduction/enhancement of diseases, predators, or parasites. In addition, forest canopy pest
control programs aimed specifically at insects may also utilize sterile insect release, mating
disruption, and biological pesticides. While biological controls generally have limited
applications for forest canopy pest control programs, they should be fully considered as an
option in the development of Pest Management Measures. The latter two control approaches are
often utilized when controlling for gypsy moth.

Pesticides

Several chemical and biological pesticides are available that may be used to reduce
defoliation of the trees. These pesticides are typically used when pest populations are high, and
the action threshold has been reached. They are aerially applied. As described below, once the
determination is made to use pesticides, additional requirements must be met.

Part 2.2.4.C. — Pesticide Use

Conduct surveillance in an area that is representative of the pest problem prior to
each application to assess the pest management area and to determine when the pest action
threshold is met. Decision-makers must apply pesticides only as needed as determined by pre-
established criteria and pest action thresholds. Decision-makers must establish a pest action
threshold that warrants pesticide application based on problem identification and pest
surveillance. In order to establish pest densities and determine when pest action thresholds have
been met, forest canopy pest control programs must include pest surveillance activities as an
integral component of Pest Management Measures. Pest surveillance is necessary to detect the
presence (or confirm the absence) and magnitude of pest populations in a given location and
precisely pinpoint zones of infestation. Surveillance activities will vary according to the pest
(insect, weed, or pathogen) but in general should include observations of pest numbers,
developmental stage of the current infestation, and biotic factors which would enhance
development/expansion of pest populations (e.g., weather, crowding, predators, pathogens, etc.).

Pest surveillance will vary according to pest type and species. For insect pests, surveillance
activities may include, but not be limited to, pheromone traps, sticky traps, light traps,
defoliation monitoring. In some cases, traps used in surveillance activities have been developed
to the extent that they alone provide adequate control of the targeted pest, thus eliminating the
need for pesticides completely. Conversely, in the instance of quarantine pests or invasive
species, pest identification alone may suffice to fulfill surveillance requirements and indicate
need for control measures. Regardless, surveillance should take into account local environmental
conditions and projected environmental conditions, which would support development and/or

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spread of the pest population and which would limit the choice or effectiveness of control
activities.

It is also important to continue surveillance following control activities to assess the
efficacy of Pest Management Measures and to monitor for new pests. Surveillance can determine
if the current techniques are effective and whether additional Pest Management Measures are
required, particularly pesticide application. Based on follow-up surveillance activity, Decision-
makers can make informed decisions which serve to increase the effectiveness of their control
programs and minimize the potential for pollutant discharges to waters of the United States.
Surveillance is necessary not only to establish the pest presence and its abundance but also as an
evaluation tool of the effectiveness of chemical control activities. Furthermore, surveillance
should be used as an indicator of the need for additional chemical control activities based on pre-
established criteria related to population densities in local areas.

Reduce the impact on the environment and non-target organisms by evaluating the
restrictions, application timing, and application methods in addition to applying the
pesticide only when the action threshold(s) have been met. Forest canopy pest and site
restrictions (water use, water movement, etc.) must be identified when choosing an appropriate
pesticide. For instance, with gypsy moth control, a biological insecticide, Bacillus thuringiensis
kurstaki, is usually selected. However, if endangered or threatened butterfly or moth species are
in the area, a viral insecticide that specifically targets gypsy moth larvae should be considered.
Environmental factors such as temperature, as well as biological factors such as migration
timing, should be considered when deciding on application timing. Partial site pesticide
applications over time may be considered to minimize risk to non-target organisms. Pesticide
application must be limited to the appropriate amount required to control the target pests.
Methods used in applying pesticides should weigh the potential impact to non-target species.

Evaluate using pesticides against the most susceptible developmental stage. For forest
canopy pests, pesticides should be selected that target the most susceptible life stage. Gypsy
moth caterpillars are susceptible to control by chemical pesticides, or by ingestion of
nucleopolyhedrosis virus occlusion bodies.

For additional information on this pesticide use pattern, see Appendix H of this fact sheet.

3. Water Quality-Based Effluent Limitations

In addition to technology-based effluent limitations for all discharges of pollutants, the
CWA requires additional effluent limitations that are as stringent as necessary to achieve water
quality standards. These are called water quality-based effluent limitations (WQBELs). Permit
writers are to assess whether the technology-based effluent limitations are protective of water
quality standards, and if not, permit writers must also include WQBELs as necessary to ensure
that the discharge of pollutants will not cause an excursion above any state water quality
standard, including state narrative criteria for water quality (see 40 CFR 122.44(d)). In
developing WQBELs, permit writers must consider the potential impact of every proposed
surface water discharge of pollutants on the quality of the receiving water. Unlike individual
permits that include requirements tailored to site-specific considerations, general permits, while
tailored to specific industrial processes or types of discharges of pollutants (e.g., from the

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application of pesticides), often do not contain site-specific WQBELs. Instead, in general, EPA
includes a narrative statement that addresses WQBELs. In this permit the WQBEL is as follows:

All Operators must control discharges as necessary to meet applicable numeric and
narrative state, territory, or tribal water quality standards, for any discharges authorized
under this permit, with compliance required upon beginning such discharge.

If at any time an Operator becomes aware (e.g., through self-monitoring or by
notification from the state, tribe, or territory), or EPA determines, that a discharge
causes or contributes to an excursion of any applicable water quality standards, the
Operator must take corrective action as required in Part 6 up to and including the
ceasing of the discharge, if necessary.

The first sentence includes the general requirement to control discharges of pollutants as
necessary to meet water quality standards, while the second sentence implements this
requirement in more specific terms by imposing on Operators a responsibility to take corrective
action in response to an excursion of applicable water quality standards, whether discovered by
EPA or by the Operator. Failure to take such corrective action is a violation of the permit.
Additionally, the permit includes a provision, in Part 1.2.3 of the PGP, that specifies that EPA
may determine that additional technology-based and/or water quality-based effluent limitations
are necessary, or may deny coverage under this permit and require submission of an application
for an individual NPDES permit, as detailed in Part 1.3.

Each Operator is required to control its discharge of pollutants as necessary to meet
applicable water quality standards. In general, EPA expects that compliance with the other
conditions in this permit (e.g., the technology-based limitations, corrective actions, etc.) will
result in discharges of pollutants that are controlled as necessary to meet applicable water quality
standards based on the cumulative effect of the following factors, which are described below and
discussed further in Appendix I of this fact sheet:

(1) Under FIFRA, EPA evaluates risk associated with pesticides and mitigates
unreasonable ecological risk. Compliance with FIFRA is required. (See Part III. 1.5 of
this fact sheet.)

(2) In developing the PGP, EPA evaluated national-scale ambient monitoring data, as well
as the frequency of the identification of specific pesticides as the cause of water
impairments, to assess whether pesticide residues are currently present in waters at levels
that would exceed water quality standards. The monitoring data, although limited in scope,
show that, in most samples, most pesticides were below ambient water quality criteria or
benchmarks developed by EPA's Office of Pesticide Programs (OPP).

(3) Technology-based effluent limitations in the PGP provide further protections beyond
compliance with existing FIFRA requirements.

(4) Biological pesticides discharged to waters, by regulatory definition, do not work
through a toxic mode of action. For chemical pesticides, the discharges of pollutants
covered under the PGP are the residues after the pesticide has performed its intended
purpose. Thus, the residue will be no higher than, and in many instances, lower than,
the concentration of the pesticide as applied.

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(5) The PGP excludes pesticide applications that result in discharges of any pollutant to
(1) waters impaired for an active ingredient of that pesticide or a degradate of such an
active ingredient, or (2) any Tier 3 waters {i.e., outstanding national resource waters)
except for pesticide applications made to restore or maintain water quality or to protect
public health or the environment that either do not degrade water quality or only
degrade water quality on a short-term or temporary basis.

(6) EPA has no evidence in the record that implementation of previously issued PGPs has
resulted in documented water quality problems.

In addition to the six factors identified above, EPA cannot issue an NPDES permit until the
state, territory or tribe in which the discharge originates certifies that the discharge will comply
with applicable provisions of the CWA or waives certification. Therefore, Part 9 of the final PGP
will include conditions included by States, and authorized Tribes in their CWA § 401
certification actions on the draft 2026 PGP, which meet the requirements of CWA Section 401
and EPA's CWA Section 401 implementing regulations. 40 C.F.R. § 124.53(e)(1).

This PGP requires Operators to control discharges of pollutants as necessary to meet
applicable water quality standards. When the Operator or EPA determines a discharge of
pollutants will cause or contribute to an excursion above any WQS, including failure to protect
and maintain existing designated uses of receiving waters, the Operator must take corrective
action to ensure that the situation is eliminated and will not be repeated in the future. (See Part
6.0 of the PGP). If additional Pest Management Measures are required, the Operator is required
to follow and document, as applicable, the process for Pest Management Measure selection,
installation, implementation and maintenance, and cooperate to eliminate the identified problem
within the timeframe stipulated in Part 6.0 of the PGP.

4. Site Monitoring

Monitoring is required in any NPDES permit to demonstrate compliance with the permit
conditions. Monitoring requirements apply from the time any authorized Operator begins
discharging pollutants under the draft 2026 PGP. These requirements are not tied to submission
of an NOI. There are a variety of monitoring methods that a "traditional" NPDES permit may
require, including end-of-pipe monitoring to show compliance with relevant water quality-based
and technology-based effluent limitations prior to discharging pollutants to a receiving
waterbody. Monitoring may also pertain to actions taken to ensure that recordkeeping or other
permit control activities are being properly implemented. Water quality monitoring of receiving
streams is not typically required in NPDES permits unless it is required to determine among
other things, compliance with mixing zone dilution standards or some other special permit
condition.

Pursuant to CWA sections 308 and 402(a)(2), 40 CFR 122.43(a), and other applicable
implementing regulations, the following requirements have been included in the permit, as
discussed below. The monitoring requirements of the draft 2026 PGP are narrative and
demonstrate compliance with permit conditions by using currently established pesticide use
routines for monitoring pest control. For instance, the draft 2026 PGP requires routine visual
inspections (described below) to be conducted as part of the pest control activity and/or as part of
post-application pest surveillance and calls for records of the pollutant discharge volume to be

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kept. The monitoring requirements of the permit are reasonable measures of good pest
management practice that the conscientious Operator should be currently employing to ensure
environmental health and safety and optimal control of pest organisms.

Monitoring of pollutant discharges poses several challenges not generally encountered in
"traditional" NPDES permitting situations. For example, there is no "wastewater discharge" per
se from pesticide applications that is analogous to end-of-pipe discharges of pollutants. For
example, a manufacturing plant would typically direct its wastewater through a treatment system
to remove pollutants, and then would direct the effluent through a pipe into a receiving
waterbody. However, for chemical pesticide applications, at the time of application the pesticide
contains both the portion serving its intended purpose as well as the potential residual for which
monitoring data would be appropriate. Thus, monitoring the "outfall" in this case would merely
provide data on the amount of the product as applied (information already known through the
FIFRA registration process) and would be inappropriate to compare with any type of technology
based effluent limitation or water quality standard.

EPA considered requiring ambient water quality monitoring. However, EPA thinks that it
was infeasible for the following reasons:

1) Uncertainty: Ambient water quality monitoring would generally not be able to
distinguish whether the results were from the pesticide application for which monitoring
is being performed, or some other upstream source.

2) Safety and Accessibility: Pesticides, particularly those used for mosquito control and
forestry pest control, are often applied over waterbodies in remote areas, hazardous
terrain, and swamps that are either inaccessible or pose safety risks for the collection of
samples.

3) Difficulty of residue sampling for chemical pesticides: For chemical pesticides, the
"pollutant" regulated by the PGP is the residue that remains after the pesticide has
completed its activity, and it is this residue that would be the subject of any water
quality monitoring requirement. However, the point at which only "residue" remains is
not practically discernable currently for all pesticides.

4) Usefulness of data: Some states have questioned the value of ambient water quality
monitoring data obtained from state permitting programs. The data generally showed
that water quality impacts were not occurring, and one state even discontinued the
requirement in revisions of its state permit.

Given the infeasibility of requiring ambient water quality data to demonstrate permit
compliance, EPA thinks that there are suitable alternative monitoring activities to determine
permit compliance, other than ambient water quality monitoring, for the PGP.

Additionally, in assessing the appropriateness of requiring ambient water quality
monitoring, EPA also considered Whole Effluent Toxicity (WET) testing as a possible option for
assessing Operator compliance with permit conditions; however, WET testing in an NPDES
permit program is best used to monitor whether an Operator's discharge of pollutants is toxic and
not whether a receiving stream (i.e., the ambient environment), that may be influenced by a
number of different discharges of pollutants from different Operators and different sources, is
toxic. In addition, WET testing would not indicate the actual source of the toxicity. If a

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waterbody is found to be toxic or to contain pollutants above water quality standards, it can be
quite complex to identify the source of the toxicity, which may or may not actually be the
NPDES permittee performing the monitoring.

Thus, the monitoring program that EPA has developed for the PGP has been tailored to
accommodate the unique situations related to pesticide applications. Routine visual monitoring is
required in the PGP and can be used to determine if any pesticide use practices may need to be
revised to ensure that avoidable adverse impacts to the environment do not occur (See Part
III.4.2 of this fact sheet). Monitoring records required by those Operators who submit NOIs will
establish a history that may indicate if or when practices need to be reconsidered. The monitoring
requirements in the PGP remain largely unchanged from EPA's 2021 PGP. NOTE: EPA is
proposing to add new Part 4.3 to reiterate the visual monitoring recordkeeping requirements in
Part 7 of the draft 2026 PGP. EPA is also proposing to add new Part 4.4 to emphasize that
additional monitoring could be required by EPA to ensure compliance with the PGP. These
proposals are discussed further below.

4.1 Visual Monitoring Requirements for Pesticide Applicators

Visual monitoring assessments are required as a means of identifying, for example,
instances of detrimental impact to non-target organisms, disruption or degradation of wildlife
habitat, or the prevention of designated recreational or municipal uses of a waterbody that may
possibly be related to the Operator's use of pesticides in a given area. This requirement consists
of visually monitoring the area to and around where pesticides are applied for possible and
observable adverse incidents, such as unanticipated death or distress of non-target organisms and
disruption of wildlife habitat, recreational or municipal water use. EPA expects that all
Operators, through a visual assessment, will be able to identify and report immediately
observable adverse effects on the environment - an occurrence that may imply that a pesticide
has been improperly applied or that compliance with the effluent limits of the permit has not
been achieved. As required by Part 6 of the draft 2026 PGP, Operators must take corrective
action by determining if changes to Pest Management Measures are necessary, and making sure
changes are made before or, if not practicable, as soon as possible after the next pesticide
application that results in a discharge, and report adverse incidents within 24 hours of the
Operator becoming aware of the adverse incident. Visual monitoring does not require detailed
point intercept quantitative assessments. The permit requires that Operators, to the best of their
ability, inspect in and around where pesticides are applied for possible and observable adverse
incidents, such as unanticipated death or distress of non-target organisms and disruption of
wildlife habitat, recreational or municipal water use. The requirement is universally applicable to
all waterbody types.

Visual monitoring assessments are required during the pesticide application when
feasibility and safety allow. Visual monitoring is generally not required during pesticide
application when that application is performed in darkness as it would be infeasible for the
inspector to note adverse effects under these circumstances. Additionally, the following
scenarios often preclude visual monitoring during pesticide application:

1. Applications made from an aircraft

2. Applications made from a moving road vehicle when the Applicator is the driver

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

3.	Applications made from moving watercraft when the Applicator is the driver

4.	Applications made from a moving off-road wheeled or tracked vehicle when the
Applicator is the driver.

However, if visual monitoring is safe and feasible during these application scenarios, it is
required by the permit.

4.2 Visual Monitoring Requirements for all Operators

Visual monitoring must also be conducted during any post-application surveillance, such as to
determine the efficacy of the pesticide application. Visual monitoring of this type is required of
all Operators but only if the Operator, be it the Applicator or the Decision-maker or both,
performs post application surveillance in the ordinary course of business. EPA expects that post-
application visual assessments are reasonably conducted on foot or from a stationary vehicle,
although they might also be conducted from a moving vehicle, including a boat or plane, in
certain circumstances. Pest Management measures, efficacy, testing, safety, and availability of
manpower are among the variety of factors related to when post application monitoring is best
performed which do not lend themselves to a particular point in time to be specified in a general
permit.

During the post treatment or post application phase, if a Decision-maker (such as a lake
association) or a pesticide Applicator returns to the treatment area to evaluate treatment
effectiveness or otherwise finalize treatment activity, then that Operator must visually inspect
any portion of the treatment area being reviewed and note and report any adverse incident (as
defined in Appendix A of the permit) that may have resulted from a discharge related to the
pesticide treatment. For-hire applicators and Decision-makers who are required to submit an NOI
must document if post application visual monitoring was conducted and if not, why not.

EPA expects that all Operators, through a visual assessment, will be able to identify and report
adverse effects - an occurrence which may imply that a pesticide has been improperly applied or
that compliance with the effluent limits of the permit has not been achieved. The language
"including but not limited to the unanticipated death or distress of non-target organisms" conveys
EPA's intent for Operators to identify and report adverse effects that are abnormal in the context
of typical pesticide use. Operators should watch for distressed or dead juvenile and small fish,
washed up or floating fish, fish swimming abnormally or erratically, fish lying lethargically at
the water surface or in shallow water, fish that are listless or nonresponsive to disturbance, the
stunting, wilting, or desiccation of nontarget submerged or emergent aquatic plants, and other
dead or visibly distressed non-target organisms including amphibians, turtles, and macro-
invertebrates.

Regarding the level of effort to be contributed to visual monitoring, a "casual stroll" through the
treatment area would be generally insufficient for the purposes of ensuring treatment efficacy or
for observing adverse incidents. Operators who return to the treatment area for post application
assessments will perform a thorough inspection to ensure that the treatment has been effective,
and EPA expects that they will watch for adverse impacts with an equal level of scrutiny.

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Visual monitoring as required in the PGP (Part 4.2) is a tool to identify, respond to, and correct
potential problems. The PGP requires reevaluation of Pest Management Measures to reduce
impacts related to pesticide applications. Adverse incident observation cannot, in and of itself,
determine whether the appropriate level of pesticide has been applied. However, EPA expects
that Operators, using their best professional judgment, should be able to observe and report off-
target mortality that is outside the range of usual and acceptable impacts.

4.3 Documentation of Visual Monitoring

In the draft 2026 PGP, EPA proposes the addition of Part 4.3, Documentation of Visual
Monitoring. Part 4.3.a reiterates the recordkeeping requirement in Part 7.2 of the permit for all
For-Hire Applicators to document the findings of each visual monitoring during application. Part
4.3.b reiterates the recordkeeping requirement in Parts 7.3 and 7.4 of the permit for Decision-
makers required to submit an NOI to document the findings of each visual monitoring during
post application surveillance. If no visual monitoring was conducted, the reason why no visual
monitoring was conducted must be documented.

4.4 Additional Monitoring

EPA proposes the addition of Part 4.4 in the draft 2026 PGP, Additional Monitoring, to
emphasize that additional monitoring could be required by EPA to ensure compliance with the
PGP. If EPA determines that additional monitoring is appropriate to ensure compliance with the
permit's technology-based and/or the water quality-based effluent limitations, EPA shall notify
the Operator of additional monitoring requirements. Any such notice shall briefly state the
reasons for the monitoring; locations and parameters to be monitored; frequency and period of
monitoring; sample types; and reporting requirements. For example, EPA may require additional
monitoring when the Agency determines:

a. The Operator's treatment activity likely contributed to a reported adverse incident;

b. The pesticide used in treatment contains components for which additional controls may
be necessary;

c. The pesticide used in treatment raises water quality concerns;

d. More information about the pesticide use at issue is needed to determine if effluent
limitations should be modified;

e. The Operator is not in compliance with several permit conditions;

f. A change has occurred in the availability of demonstrated technology or practices for the
reduction of discharges from the application of pesticides; or

g. Additional permit requirements may be necessary in light of federally threatened or
endangered species.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

5. Pesticide Discharge Management Plan (PDMP)

Any Decision-maker who is or will be required to submit an NOI and is not a small entity8
must develop a PDMP, except for any pesticide applications made in response to a Declared Pest
Emergency situation, as defined in Appendix A of the PGP or any Decision-maker who is or will
be required to submit an NOI solely because of discharges of pollutants to waters of the United
States containing NMFS Listed Resources of Concern, as defined in Appendix A of the PGP.
EPA defines a Decision-maker that is not a small entity as a large entity in the permit. Large
entity Decision-makers must prepare the PDMP by the time the NOI is filed. NOTE: EPA is
proposing the same ESA procedures for FWS under the draft 2026 PGP as described above for
NMFS. The exception for a Decision-maker who is or will be required to submit an NOI solely
because of discharges of pollutants to waters of the United States containing NMFS Listed
Resources of Concern also applies to FWS Listed Resources of Concern.

Any Decision-maker who is or will be required to submit an NOI and is a small entity {i.e.,
is below the Small Business Association (SBA) size standard, as defined in 13 CFR. 121.201, or
is a public entity serving a population of 10,000 or less), is not required to develop a PDMP.
Small entity Decision-makers are required to document activities as described in Part III.7.3 of
this fact sheet. EPA recognizes that the SBA defines "small entities" as including government
entities that serve populations of less than 50,000 persons. However, EPA's NPDES program has
historically considered "major" municipal NPDES permits as those that serve greater than
10,000 persons {i.e., with a wastewater treatment plant design of greater than one million gallons
a day). 'Major NPDES' permittees have increased recordkeeping and public notice obligations
over 'minor NPDES,' which is consistent with EPA's intent for the PGP to impose additional
recordkeeping and reporting information only on these larger communities.

The PDMP itself does not contain effluent limitations; rather it constitutes a tool both to
assist the Decision-maker in documenting what pest management measures it is implementing to
meet the effluent limitations, and to assist the permitting/compliance authority in determining
whether the effluent limitations are being met. Developing a PDMP helps Decision-makers
ensure they have (1) taken steps to identify the pest problem, (2) evaluated pest management
options, and (3) selected appropriate pest management measures to control pollutant discharges.
A PDMP is a "living" document that requires reviews and must be kept up-to-date. Where pest
management measures are modified or replaced to meet effluent limitations, such as in response
to a Part 6.1 triggering condition in the PGP, such changes must be documented in the PDMP.
All changes to the PDMP must be made before the next pesticide application that results in a
discharge of pollutants, if practicable, or if not, no later than 90 days after any change in
pesticide application activities. Failure of a Decision-maker to develop and maintain an up-to-
date PDMP is a violation of the PGP. This recordkeeping violation is separate and distinct from a
violation of any of the other substantive requirements in the permit {e.g., effluent limitations,
corrective action, monitoring, reporting, and state-specific requirements).

A PDMP must include identification of the pesticide discharge management team, a
description of the pest problem, and a description of the pest management options evaluation.

8 A small entity is any (1) private enterprise that does not exceed the Small Business Administration size standard as
identified at 13 CFR 121.201, or (2) local government that serves a population of 10,000 or less.

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Decision-makers must also provide response procedures for spill response and adverse incident
response. The size of a pest management area is determined by the Decision-maker responsible
for and with the authority to conduct pest management activities. For example, the pest
management area for a mosquito control district is the total area of the district. Once the plan is
developed, the Decision-maker must maintain the plan thereafter for the duration of coverage
under this general permit. For any Decision-maker for which the annual treatment area threshold
triggers the NOI requirement (and the Decision-maker is a large entity), the Decision-maker
must keep the plan up-to-date for the duration of permit coverage even if the annual treatment
area subsequently falls below the annual treatment area threshold.

Decision-makers may choose to reference other documents, such as a pre-existing pest
management plan or spill prevention and response plan, in the PDMP rather than recreating the
same text in the PDMP. It is not required that a Decision-maker must have authored the pre-
existing plan in order to use it. When referencing other documents, the Decision-maker is
responsible for ensuring his/her PDMP and the other documents together contain all the
necessary elements for a complete PDMP, as specified in Part 5.1 of the PGP. In addition, the
Decision-maker must ensure that a copy of relevant portions of those referenced documents is
attached to the PDMP. NOTE: EPA is proposing that Decision-makers submit the PDMP to EPA
when the NOI is filed. See discussion on Part 5.3 of the PGP for more information.

5.1 Contents of the PDMP

The PDMP prepared under the PGP must meet specific requirements under Part 5.1 of the PGP.
Generally, Decision-makers must document the following: (1) a pesticide discharge management
team; (2) a description of the pest management area and the pest problem; (3) a description of
pest management options evaluation; (4) response procedures for spill response and adverse
incident response; and (5) any eligibility considerations under other federal laws. NOTE: EPA is
proposing to add a requirement for visual monitoring planning under the response procedures
section of the plan. See discussion below for more information.

Pesticide Discharge Management Team

The PGP requires that a qualified individual or team of individuals be identified to manage
pollutant discharges covered under the permit. Identification of a pesticide discharge
management team ensures that appropriate persons (or positions) are identified as necessary for
developing and implementing the plan. Inclusion of the team in the plan provides notice to staff
and management {i.e., those responsible for signing and certifying the plan) of the
responsibilities of certain key staff for following through on compliance with the permit's
conditions and limits.

The pesticide discharge management team is responsible for developing and revising the
PDMP, implementing and maintaining the Pest Management Measures to meet effluent
limitations, and taking corrective action where necessary. Team members should be chosen for
their expertise in the relevant areas to ensure that all aspects of pest management are considered
in developing the plan. The PDMP must clearly describe the responsibilities of each team
member to ensure that each aspect of the PDMP is addressed. EPA expects most Decision-
makers will have more than one individual on the team, except for those with relatively simple

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plans and/or staff limitations. The PGP requires that team members have ready access to any
applicable portions of the PDMP and the permit.

Problem Identification

This section includes the pest problem description, action threshold(s), a general location
map, and water quality standards.

1. Pest Problem Description.

The PGP requires that the PDMP include a description of the pest problem at the pest
management area. A detailed pest management area description assists Decision-makers in
subsequent efforts to identify and set priorities for the evaluation and selection of Pest
Management Measures taken to meet effluent limitations set forth in Parts 2 and 3 of the PGP
and in identifying necessary changes in pest management. The description must include
identification of the target pest(s), source of the pest problem, and source of data used to identify
the problem. The PGP allows use of historical data or other available data (e.g., from another
similar site) to identify the problem at your site. If you use other site data, you must document in
this section why data from your site is not available or not taken within the past year and explain
why the data is relevant to your site. Additionally, the pest management area descriptions should
include any sensitive resources in the area, such as unique habitat areas, rare or listed species, or
other species of concern that may limit pest management options.

2. Action Threshold(s)

The PGP requires that the PDMP include a description of the action threshold(s)
established for the target pest, including a description of how they were determined and
method(s) to determine when the action threshold(s) has been met. An action threshold is a level
of pest prevalence (or other indicator) at which an Operator takes action to reduce the pest
population.

3. General Location Map

The PDMP must also contain a general location map of the site that identifies the
geographic boundaries of the area to which the plan applies and location of the waters of the
United States. To improve readability of the map, some detailed information may be kept as an
attachment to the site map and pictures may be included as deemed appropriate.

4. Water Quality Standards

Operators must identify any Tier 3 Waters (Outstanding National Resource Waters) and
any water(s) impaired for a specific pesticide or its degradates to which there may be a discharge
of pollutants. Internet links to all State, Territory and Tribal water quality standards are available
at: http://www.epa. gov/wqs-tech.

Description of Pest Management Measures Options Evaluation

The PGP requires that the PDMP include a description of the Pest Management Measures
implemented to meet the applicable technology-based or water quality-based effluent limitations.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

The description must include a brief explanation of the Pest Management Measures used at the
site to reduce pollutant discharge, including evaluation and implementation of the six
management options (no action, prevention, mechanical/physical methods, cultural methods,
biological control agents, and pesticides). Decision-makers must consider impact to non-target
organisms, impact to water quality, feasibility, and cost effectiveness when evaluating and
selecting the most efficient and effective means of Pest Management Measures to minimize
pollutant discharge to waters of the United States.

All six management options may not be available for a specific use category and/or
treatment area. However, the PDMP must include documentation of how the six management
options, including combination of these options, were evaluated prior to selecting site specific
Pest Management Measures. For the no action option, Operators should document the impact of
this option without any current Pest Management Measures at the site. For the prevention
management option, the Decision-maker should document the methods implemented to prevent
new introductions or the spread of the pests to new sites, such as identifying routes of invasion
and how these can be intercepted to reduce the chance of invasion. Prevention may include
source reduction, using pathogen-free or weed-free seeds or fill; exclusion methods (e.g.,
barriers) and/or sanitation methods, like wash stations, to prevent reintroduction by vehicles,
personnel, etc. Some prevention management methods may fall under mechanical/physical or
cultural methods, as well.

For the pesticide management option, Decision-makers may include a list of active
ingredients evaluated. Discussion may also identify specific equipment or methods that will
prevent or reduce the risks to non-target organisms and pollutant discharges to waters of the
United States.

Response Procedures

The following procedures necessary to minimize discharges of pollutants must be documented in
the PDMP:

1. Spill Response Procedures

The PDMP must document procedures for expeditiously stopping, containing, and cleaning
up leaks, spills, and other release. In addition, the PDMP must include documentation of the
procedures for notification of appropriate facility personnel, emergency response agencies, and
regulatory agencies.

2. Adverse Incident Response Procedures

In the PDMP, Decision-makers must document appropriate procedures for responding to an
adverse incident resulting from pesticide applications. Decision-makers must identify and
document the following:

- Procedures for responding to any adverse incident resulting from pesticide applications;

- Procedures for notification of the adverse incident, both internal to the Decision-
maker's agency/organization and external;

- State/Federal permitting agency contacts with phone numbers;

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

- Name, location, and telephone of nearest emergency medical facility; and

- Name, location, and telephone of nearest hazardous chemical responder (including
police and fire department).

3. Visual Monitoring Procedures

Under the draft 2026 PGP, EPA proposes documentation of visual monitoring procedures
in the PDMP. The PDMP must include the following to address visual monitoring:

- The process for determining the location(s) of visual monitoring;

- A schedule and procedures for visual monitoring;

- The individual(s) or position responsible for conducting visual monitoring; and

- Procedures for documenting visual monitoring including the date, time, and location.

Documentation to Support Eligibility Considerations under other Federal Laws

Decision-makers must keep, with the PDMP, documentation supporting their determination
regarding Part 1.1.2.4 of the PGP (Endangered and Threatened Species and Critical Habitat
Protection).

Signature Requirements

The PDMP must be signed and certified in accordance with the signatory requirements in
the Standard Permit Conditions part of the PGP (Appendix B, 40 CFR 122.41(k) Signatory
requirement). This requirement is consistent with standard NPDES permit conditions described
in 40 CFR 122.22 and is intended to ensure that the Decision-maker understands their
responsibility to create and maintain a complete and accurate PDMP. The signature requirement
includes an acknowledgment that there are significant penalties for submitting false information.

5.2 Pesticide Discharge Management Plan Modifications.

The PGP requires that the PDMP be updated whenever any of the triggering conditions for
corrective action in Part 6.1 of the PGP occur, or when a review following the triggering
conditions in Part 6.1 requires the Operator to revise his/her Pest Management Measures as
necessary to meet the effluent limitations in the PGP (Part 2). Keeping the PDMP up-to-date will
help the Decision-maker ensure that the condition that triggered the corrective action does not
reoccur. All changes to the PDMP must be made before the next pesticide application that results
in a discharge of pollutants, if practicable, or if not, no later than 90 days after any change in
pesticide application activities or after an annual review.

It is important to note that failure to update the PDMP in accordance with Part 5.2 of the
PGP is a recordkeeping violation, not a violation of an effluent limit. For example, if the
Decision-maker changes its spill response procedures but fails to update its PDMP to reflect
these changes, a recordkeeping violation will result. The Decision-maker must revise its PDMP
to reflect the new procedures and include documentation of the corrective action (in accordance
with Part 6 of the PGP) to return to full compliance. NOTE: EPA is proposing in the draft 2026
PGP that Decision-makers submit their PDMP when filing their NOIs. When the PDMP is
modified, Decision-makers must also submit the revised PDMP within 15 days.

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5.3 Pesticide Discharge Management Plan Availability.

The PDMP and all supporting documents must be immediately available to representatives
of EPA, a state, tribal, or local agency governing pesticide applications, as well as
representatives of the United States Fish and Wildlife Service (FWS) or the National Marine
Fisheries Service (NMFS) at the time of an on-site inspection or upon request. Part 5.3 of the
PGP indicates that EPA may provide access to portions of your PDMP to a member of the public
upon request. Confidential Business Information (CBI) may be withheld from the public, but
consistent with 40 CFR Part 2, may not be withheld from EPA or the Services. NOTE: EPA is
proposing in the draft 2026 PGP that Decision-makers required to prepare a PDMP must submit
the PDMP with their NOI using NeT, along with all supporting maps and documents. The PDMP
will be available on EPA's website with the NOI. A modified PDMP must also be submitted
using NeT within 15 days.

6. Corrective Action

The purpose of including corrective action requirements in the PGP is to assist this
universe of NPDES permittees with effectively meeting technology-based and water-quality-
based effluent limitations and implementing Pest Management Measures in the PGP. Corrective
action requirements apply from the time any authorized Operator begins discharging pollutants
under the PGP. These requirements are not tied to submission of an NOI. Corrective actions in
this permit are follow-up actions an Operator must take to assess and correct problems. They
require review and revision of Pest Management Measures and pesticide application activities, as
necessary, to ensure that these problems are eliminated and will not be repeated in the future.
The PGP makes clear that the Operator is expected to assess why a specific problem has
occurred and document what steps were taken to eliminate the problem. This approach will help
Operators in complying with the requirements of the permit on a consistent basis. Compliance
issues with some of the permit's requirements — for instance, those related to reporting and
recordkeeping and some of those related to operation and maintenance — may be able to be
corrected immediately simply by following already established procedures, and therefore, are not
considered problems that trigger the corrective action provisions of the PGP.

It should be noted that a situation triggering corrective action is not necessarily a permit
violation and, as such, may not necessarily trigger a modification of Pest Management Measures
to meet effluent limitations. However, failure to conduct (and document) corrective action
reviews in such cases does constitute a permit violation.

6.1 Situations Requiring Revision of Pest Management Measures

Operators are required to review and, as necessary, revise the selection and implementation
of their Pest Management Measures to eliminate any of the following situations:

- An unauthorized release or discharge of pollutants associated with the application of
pesticides (e.g., spill, leak, or discharge not authorized by this or another NPDES
permit) occurs;

- Operators become aware, or EPA concludes, that Pest Management Measures are not
adequate/sufficient for the discharge of pollutants to meet applicable water quality
standards;

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- Any monitoring activities indicate failure to meet applicable technology-based effluent
limitations in Part 2 of the PGP;

- An inspection or evaluation by an EPA official, or local, state, or Tribal entity,
determines that modifications are necessary to meet the non-numeric effluent
limitations detailed in Part 2 of the PGP; or

- An Operator observes or is otherwise made aware (e.g., a third-party notification) of an
adverse incident.

EPA considers the above situations to be of significant concern. Thus, EPA is requiring
Operators to assess the cause of these situations, which may be affiliated with the Operator's
discharge from the application of pesticides and to take any necessary steps to eliminate the
situation and ensure that the situation will not be repeated in the future.

The purpose of Part 6.1 of the PGP is to ensure compliance with corrective action
requirements through increased accountability and oversight. EPA views ongoing assessment of
the effectiveness of Pest Management Measures and corrective actions as integral to an effective
pesticide management program. Written records associated with corrective action assessments
must be kept with the other recordkeeping documentation required by this permit.

6.2 Corrective Action Deadlines

The PGP requires that corrective action be completed "before or, if not practicable, as soon
as possible after the next pesticide application that results in a discharge." EPA emphasizes that
this timeframe is not a grace period within which an Operator is relieved of any liability for a
permit violation. EPA is adopting this flexible deadline to account for the variation in types of
responses (e.g., evaluate situation and select, design, install, and implement new or modified Pest
Management Measures) that may be necessary to address any identified situations of concern.
EPA recognizes that in rare cases a corrective action review may identify the need for substantial
improvements to the Operator's Pest Management Measures and does not want to limit the
selection and implementation of such controls with an inflexible deadline. Another possibility is
that EPA or the Operator may determine that further monitoring is needed under Part 6.3 of the
PGP to pinpoint the source of the problem, and this monitoring may need to be conducted during
future pesticide application activities. In most cases, however, corrective action reviews will
identify responses that can be taken quickly, either before the next pesticide application that
results in a discharge or shortly thereafter.

6.3 Effect of Corrective Action

The occurrence of a situation described in Part 6.1 of the PGP may, but does not
necessarily, constitute a violation of the PGP. The occurrence of a situation identified in Part 6.1
does require the Operator to immediately review and as necessary, revise the selection and
implementation of their Pest Management Measures to eliminate the situation. Part 6.3 of the
PGP explains that taking corrective action does not absolve the Operator of any liability for a
permit violation requiring that action, however, failure to take required corrective action will
constitute an original or an additional permit violation. EPA will consider the appropriateness
and promptness of corrective action in determining enforcement responses to permit violations.
EPA may impose additional requirements and schedules of compliance, including requirements

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

to submit additional information concerning the condition(s) triggering corrective action,
additional site-specific water-quality based limitations, additional monitoring requirements, or
other schedules and requirements more stringent than specified in this permit. Those
requirements and schedules will supersede those of Parts 6.1 and 6.2 of the PGP if such
requirements conflict.

6.4 Adverse Incident Documentation and Reporting

Part 6.4 of the PGP requires Operators to take specific actions in response to identified
adverse incidents which may have resulted from a discharge from the Operator's pesticide
application. Namely, Operators are required to provide oral notice to EPA within 24 hours and
then follow-up with a written report within 30 days of becoming aware of the adverse incident.
EPA defines an "adverse incident" in Appendix A of the PGP, but generally it is defined as any
effect of a pesticide's use that is unexpected or unintended, in which there is evidence that a
person or non-target organism has likely been exposed to a pesticide residue and suffered a toxic
or adverse effect.

Part 6.4.1 of the PGP requires Operators to call the appropriate EPA Incident Reporting
Contact within 24 hours of any identified adverse incident and provide basic information about
it. The purpose of this requirement is twofold: (1) to provide an opportunity for the Agency to
respond to these incidents as soon as reasonably can be expected, and (2) to provide a basis for
potential corrective actions. EPA does not expect this initial notification to be detailed but
merely a reporting of the date of the finding, a general discussion of the incident and a review of
the necessity to conduct corrective action. The PGP requires Operators to document the
information identified in Part 6.4.1, including the date and time that EPA was notified and a
description of any deviations from Part 6.4.1 notification requirements based on nuances of the
adverse incident. For example, an Operator may decide to notify multiple EPA contacts because
of the severity of the adverse incident. This type of information should be included in the written
documentation of the 24-hour notification as described below.

Part 6.4.2 of the PGP requires Operators to provide a written report of the adverse incident
to the appropriate EPA Regional office and the state lead agency for pesticide regulation, and if
applicable, to the Tribal lead, within 30 days of discovering the adverse incident. The adverse
incident report must include the following information:

-	Information required to be provided in Part 6.4.1.1 of the PGP;

-	Date and time you contacted EPA notifying the Agency of the adverse incident;

-	Location of incident, including the names of any waters affected and appearance of
those waters (sheen, color, clarity, etc.);

-	A description of the circumstances of the incident including species affected, number of
individuals and approximate size of dead or distressed organisms;

-	Magnitude of the effect (e.g., aquatic square area or total stream distance affected);

-	Quantity of pesticide applied and EPA registration number of pesticide product,
intended use site (e.g., banks, above, or direct to water), and method of application;

-	Description of the habitat and the circumstances under which the incident occurred
(including any available ambient water data for pesticides applied);

-	Information on any laboratory tests performed and test results; and

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- Actions to be taken to prevent recurrence of the incident.

Adverse incident information associated with discharges from the application of pesticides
is useful to the Agency because the information:

- Provides the Agency with an indication of the effectiveness of the permit in controlling
discharges of pollutants to protect water quality, including data upon which the Agency
may base future permit decisions (e.g., modifications to or reissuance of this permit).

- May be considered when reviewing applications for registration of new pesticides that
are chemically similar to existing pesticides, as well as re-evaluations of existing
pesticides;

- May be considered in ecological risk assessment and during deliberations on risk
management decisions;

- May be reviewed to determine trends that may indicate potential ecological impacts
with an existing pesticide and/or to track improvements when mitigation measures are
applied;

- Provides information on the nature, extent, and severity of incidents to decision-
makers, stakeholders, and the public; and

- Provides the Agency with information on which to assess compliance with regulatory
requirements, including documentation and reporting.

Currently, there is no database that includes adverse reporting from anyone other than the
registrant under 6(a)(2) of FIFRA. EPA does not consider inclusion of adverse incident reporting
in the NPDES permit to be a duplicative requirement to the FIFRA section 6(a)(2) requirements
for registrant reporting of adverse incidents. This is because pesticide registrants are not likely to
be directly covered under the PGP. Although some pesticide product labels may require that
adverse incidents be reported, requiring the reporting of all adverse incidents and follow-up
corrective actions may address the lack of a universal, mandatory legal duty for pesticide users to
report adverse incidents, at least for the pesticide use patterns covered by the PGP.

EPA acknowledges that assessing and correcting adverse incidents may be complicated in
certain instances. For example, symptoms associated with adverse incidents are often vague or
mimic other causes which may lead to incorrect diagnoses. Thus, it may be difficult to identify
and track chronic effects resulting from pollutant discharges. It may also be difficult to observe
adverse effects because of limited visibility or access such as dead fish poisoned in a wetland
under dense vegetation or in sparsely populated areas or because scavengers scatter or devour
carcasses before discovery. It is important, however, to identify to the extent feasible situations
where adverse effects occur where discharges from the application of pesticides also occur.

Immediately observable signs of distress or damage to non-target plants, animals and other
macro-organisms within the treatment area may warrant concern for a possible adverse incident
related to a discharge of pesticides during application. EPA acknowledges that some degree of
detrimental impact to non-target species may occur and may be acceptable during normal
pesticide application. EPA expects Operators to use their best professional judgment in
determining the extent to which non-target effects appear to be abnormal or indicative of an
unforeseen problem associated with an application of pesticides.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

During a visual inspection, Operators should watch for (1) distressed or dead juvenile and
small fish; (2) washed up or floating fish; (3) fish swimming abnormally or erratically; (4) fish
lying lethargically at the water surface or in shallow water;(5) fish that are listless or
nonresponsive to disturbance; (6) the stunting, wilting, or desiccation of non-target submerged or
emergent aquatic plants; and (7) other dead or visibly distressed non-target organisms including
amphibians, turtles, and macro-invertebrates. These observations must be noted unless they are
deemed not to be aberrant (for example, distressed non-target fish are to be expected when
conducting pest control with rotenone and non-target vegetation will be stressed near the target
of contact herbicides). It should be noted that observation of these impacts does not necessarily
imply that a pesticide has been misused or that there has been a permit violation or an instance of
noncompliance but may provide cause for further investigation of local water quality or
reconsideration of Pest Management Measures.

Complete information concerning adverse impacts will aid EPA in any review of current or
future pesticide use, adherence to Pest Management Measures, or effectiveness of these
measures. Reporting of adverse incidents is not required under this permit in the following
situations: (1) you are aware of facts that indicate that the adverse incident was not related to
toxic effects or exposure from the pesticide application; (2) you have been notified in writing by
EPA that the reporting requirement has been waived for this incident or category of incidents;
(3) you receive information notifying you of an adverse incident but that information is clearly
erroneous; (4) an adverse incident occurs to pests that are similar in kind to pests identified as
potential targets on the FIFRA label. However, even for these situations, certain records must be
kept on site by those Decision-makers who are required to submit NOIs, pursuant to Part 7.3 and

7.4	of the PGP.

6.5	Reportable Spills and Leaks

Part 6.5.1 of the PGP requires Operators to call the appropriate EPA Incident Reporting
Contact to report any spill or leak of a hazardous substance or oil into waters of the United States
with 24 hours of becoming aware of the spill or leak.9 Part 6.5.2 of the PGP requires Operators
to document this notification within 30 days of becoming aware of such spill or leak. If the spill
or leak triggers the notification in Part 6.5.1 and results in an adverse incident, then Operators
must report the incident per the guidelines in Part 6.4.1 and 6.4.2 of the PGP. If the spill or leak
triggers the notification in Part 6.5.1, but does not result in an adverse incident, then Operators
must document and retain information outlined in Part 6.5.2 within 30 days of becoming aware
of the situation. This documentation provides a written record of what you reported to EPA
orally. It should also include a description of the reporting system that will be used to alert
responsible managers and legal authorities in the event of a future spill or leak and a description
of preventive measures to prevent, contain, or treat spills and leaks of these materials. Part 6.4.3
of the PGP requires Operators to notify either the National Marine Fisheries Service or the
United States Fish and Wildlife Service if the Operator becomes aware of an incident that may
have resulted from a discharge from the pesticide application that adversely affects a federally-

9 Reportable Spills and Leaks are defined as those that trigger the requirement to notify the National Response
Center (40 CFR Parts 110, 117, 302) based on the type of pollutant and quantity released.

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listed threatened or endangered species or its federally-designated critical habitat. This
information will be used by EPA to ascertain compliance with permit conditions.

6.6 Documentation for Other Corrective Action

For any event described in Part 6.1 of the PGP, other than for adverse incidents or
reportable spills or leaks, immediate reporting to EPA is not required, but Operators must
document basic information describing the event and the Operators' response to that event within
30 days. For triggering events in Part 6.1, where the Operator determines that revision to Pest
Management Measures is not necessary, the Operator must still document the review and the
basis for this determination. EPA is not requiring Operators to submit this documentation to the
Agency. Rather, EPA expects Operators to retain this information on-site and upon request, to
make any such records available to EPA or any other Federal, state, or local regulatory agency
governing pesticide applications. A summary of this information must also be included in the
annual report for Operators subject to the annual reporting requirement.

7. Recordkeeping and Annual Reporting

The PGP requires all Decision-makers and Applicators to maintain certain records to help
them assess performance of Pest Management Measures and to document compliance with
permit conditions. Recordkeeping and reporting requirements apply from the time any authorized
Operator begins discharging pollutants under the PGP. These requirements are consistent with
Federal regulations at 40 CFR 122.41(j), but have been tailored to more closely reflect the
requirements in the PGP. The PGP requires a basic set of records to be maintained by all
Decision-makers and Applicators, as well as separate requirements depending on the type of
Operator (i.e., Applicator, For-Hire Applicators, NOI submitting Decision-maker who is a small
entity and NOI submitting Decision-maker who is a large entity). Part 7 of the PGP sets forth the
recordkeeping requirements for each of these types of Operators. Operators can rely on records
and documents developed for other programs, such as requirements under FIFRA, provided all
requirements of the permit are satisfied.

EPA has found that it is appropriate and reasonable to require different records for different
types of Operators, reasoning that the recordkeeping responsibilities assigned in the permit
reflect the nature of involvement in pesticide application activities for the Operators described.
The following sections describe the sets of records that the PGP requires different types of
Operators keep and enumerates the specific information items to be recorded.

7.1 Records to be Kept by all Operators (all Decision-makers and all Applicators)

These records must be kept by all Operators, including those not submitting an NOI.
Although this section is a universal requirement, these particular records are necessary only in
the event of an adverse incident, the case that corrective action was required, or in the event of a
discharge resulting from a spill or leak.

a. A copy of any Adverse Incident Reports (See Part 6.4.2);

b. Rationale for any determination that reporting of an identified adverse incident is not
required, consistent with allowances identified in Part 6.4.1.2;

c. A copy of any corrective action documentation (See Part 6.6); and,

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

d. A copy of any spill and leak or other unpermitted discharge of pollutants documentation
(See Part. 6.5.2)

7.2 Records to be Kept by all For-Hire Applicators

All Operators who are For-Hire Applicators, as defined in Appendix A of the PGP, must
keep the records listed above, as well as records that specifically document pesticide application
equipment maintenance and details of the pesticide application event. Since Decision-makers
who are not themselves performing pesticide applications are generally not able to record such
information, EPA requires different recordkeeping requirements depending on the type of
Operator.

a. Documentation of equipment calibration; and

b. Information on each treatment area to which pesticides are discharged, including:

1. Description of each treatment area, including location and size (acres or linear feet)
of treatment area and identification of any waters, either by name or by location, to
which pesticide(s) are discharged;

2. Pesticide use pattern(s) {i.e., mosquito and other flying insects, weed and algae,
animal pest, or forest canopy);

3. Target pest(s);

4. Name of each pesticide product used including the EPA registration number;

5. Quantity of each pesticide product applied to each treatment area;

6. Pesticide application date(s); and

7. Whether or not visual monitoring was conducted during pesticide application and/or

post-application and if not, why not; and if monitoring was conducted, the date,
time, and location and whether monitoring identified any possible or observable
adverse incidents caused by application of pesticides.

NOTE: For the draft 2026 PGP, EPA is proposing that if visual monitoring was conducted, the
record must include the date, time, and location where visual monitoring was conducted. EPA is
also correcting language here to match the permit language.

7.3 Records to be Kept by Small Entities, Submitting an NOI

As mentioned in Part 5, any Decision-maker that is required to submit an NOI and is below
the Small Business Administration (SBA) thresholds for small businesses or is a public entity
serving a population of fewer than 10,000, is defined as a small entity in the permit. Small
entities are required to keep a basic records set, outlined in Part 7.3 of the PGP, all of which can
be recorded on the Pesticide Discharge Evaluation Worksheet (PDEW) provided in the PGP
Appendix F.

Decision-makers who are required to submit an NOI and who are defined as small entities
(as identified in Part 5) are required to keep the following records at the address provided on the
NOI, as identified in Part 1.2.2 of the PGP. A worksheet for documenting this information on
each treatment area is provided in Appendix F of the PGP, PDEW.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

a.	Copy of the NOI submitted to EPA, any correspondence exchanged between the
Decision-maker and EPA specific to coverage under this permit, and a copy of the EPA
acknowledgment letter with the assigned permit tracking number;

b.	Documentation of equipment calibration (only if Decision-maker is also the Applicator);

c.	Information on each treatment area to which pesticides are discharged, including:

1.	Description of treatment area, including location and size (acres or linear feet) of
treatment area and identification of any waters of the United States, either by name
or by location, to which pesticide(s) are discharged;

2.	Pesticide use pattern(s) {i.e., mosquito and other flying insects, weed and algae,
animal pest, or forest canopy);

3.	Target pest(s) and explanation of need for pest control;

4.	Description of pest management measure(s) implemented prior to the first pesticide
application;

5.	Company name and contact information for pesticide applicator;

6.	Name of each pesticide product used including the EPA registration number;

7.	Quantity of each pesticide product applied to each treatment area;

8.	Pesticide Application Start Date;

9.	Pesticide Application End Date; and

10.	Whether or not visual monitoring was conducted during pesticide application and/or
post-application and if not, why not; and if monitoring was conducted, the date,
time, and location and whether monitoring identified any possible or observable
adverse incidents caused by application of pesticides.

NOTE: For the draft 2026 PGP, EPA is proposing that if visual monitoring was conducted, the
record must include the date, time, and location where visual monitoring was conducted. EPA is
also correcting language here to match the permit language.

7.4 Records to be Kept by Large Entities, Submitting an NOI

Any Decision-maker who is required to submit an NOI and is above the SBA threshold for
a small business or a public entity who serves a population of 10,000 or more is defined as a
large entity in the permit. Large entities are required to keep the records listed in Part 7.4 of the
PGP. EPA expects that large entities will have a greater capability than small entities to record
specific details of the pest treatment area and is therefore requiring slightly more comprehensive
recordkeeping. In addition, much of the records set for large entities are reflected in the annual
report that these entities must submit. The reported information will allow EPA to better
characterize the discharges resulting from pesticide applications in a variety of different
circumstances.

Decision-makers who are to submit an NOI and are defined as large entities (as defined in
Appendix A of the PGP) must keep the following records as identified in Part 7.4 of the PGP.

a.	Copy of the NOI submitted to EPA, any correspondence exchanged between the

Decision-maker and EPA specific to coverage under this permit, and a copy of the EPA
acknowledgment letter with the assigned permit tracking number;

b.	A copy of the PDMP, including any modifications made to the PDMP during the term of

this permit;

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

c.	Copy of annual reports submitted to EPA;

d.	Documentation of equipment calibration (only if Decision-maker is also the Applicator);

e.	Information on each treatment area to which pesticides are discharged, including:

1.	Description of each treatment area, including location and size (acres or linear feet)
of treatment area and identification of any waters of the United States, either by
name or by location, to which pesticide(s) are discharged;

2.	Pesticide use pattern(s) {i.e., mosquito and other flying insects, weed and algae,
animal pest, or forest canopy);

3.	Target pest(s) and explanation of need for pest control;

4.	Action Thresholds;

5.	Method and/or data used to determine that action threshold(s) has been met;

6.	Description of pest management measure(s) implemented prior to the first pesticide
application;

7.	Company name and contact information for pesticide applicator;

8.	Name of each pesticide product used including the EPA registration number;

9.	Quantity of each pesticide product applied to each treatment area;

10.	Pesticide application date(s); and

11.	Whether or not visual monitoring was conducted during pesticide application and/or
post-application and if not, why not; and if monitoring was conducted, the date,
time, and location and whether monitoring identified any possible or observable
adverse incidents caused by application of pesticides.

NOTE: For the draft 2026 PGP, EPA is proposing that if visual monitoring was conducted, the
record must include the date, time, and location where visual monitoring was conducted. EPA is
also correcting language here to match the permit language.

7.5	Retention of Records

All required records must be prepared as soon as possible but no later than 14 days
following completion of the associated activity. Operators must retain copies of these documents
for a period of at least 3 years from the date their coverage under this permit expires or is
terminated.

EPA recommends that all Decision-makers keep records of acres or linear miles treated
each calendar year for all applicable use patterns covered under this general permit. This record
will help Decision-makers estimate when they will exceed the annual treatment area threshold
(requiring submission of an NOI), or to complete an annual report if required.

7.6	Annual Reports

In addition to recordkeeping, EPA is requiring Decision-makers who are required to submit
an NOI and are large entities as identified in Part 5 of the PGP to submit annual reports that
contain basic information on their pollutant discharges to waters of the United States. An annual
report form, along with instructions on how to complete it is available in Appendix G of the
PGP.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

The annual report must include information for the calendar year, with the first annual
report required to include activities for the portion of the calendar year after the effective date of
the NOI. If the effective date of the NOI is after December 1, the Operator is not required to
submit an annual report for that first partial year but must submit annual reports thereafter, with
the first annual report submitted also including information from the first partial year. When an
Operator terminates permit coverage, as specified in Part 1.2.5 of the PGP, the Operator must
submit an annual report for the portion of the year up through the date of the termination. The
annual report is due no later than 45 days after the termination date, or February 15 of the
following year, whichever is earlier.

This information in the annual report will be used by EPA to assess permit compliance and
to determine whether additional controls on pollutant discharges are necessary to protect water
quality. For example, these data will help the Agency identify where pollutant discharges are
occurring, and the types of pesticides being discharged. The annual report provides specific
information concerning the scope and nature of discharges of pollutants permitted under the
PGP. Annual reports submitted under EPA's previously issued permits are available online at
https://www.epa.gov/npdes/pesticide-permitting. A summary of data submitted in the annual
reports is in the administrative record for this draft 2026 PGP. See 2022 PGP Annual Report
Data document in the docket at EPA-HQ-OW-2023-0268.

The annual report is a summary of the pest control activities for each applicable use pattern
and must contain:

a.	Decision-maker's name and contact information;

b.	NPDES permit tracking number(s);

c.	Contact person name, title, e-mail address (if any), and phone number; and

d.	For each treatment area, report the following information:

1.	Description of treatment area, including location and size (acres or linear feet) of

treatment area and identification of any waters of the United States, either by name

or by location, to which pesticide(s) are discharged;

2.	Pesticide use pattern(s) {i.e., mosquito and other flying insects, weed and algae,

animal pest, or forest canopy) and target pest(s);

3.	Company name(s) and contact information for pesticide applicator(s), if different

from the Decision-maker;

4.	Total amount of each pesticide product applied for the reporting year by the EPA

registration number(s) and by application method {e.g., aerially by fixed-wing or

rotary aircraft, ground based spray, etc.);

5.	Whether this pest control activity was addressed in a PDMP prior to pesticide

application;

6.	If applicable, any adverse incidents as a result of these treatment(s), for incidents, as

described in Part 6.4.1;

7.	If applicable, description of any corrective action(s), including spill responses,

resulting from pesticide application activities and the rationale for such action(s);
NOTE: For the draft 2026 PGP, EPA is proposing to require Decision-makers to submit copies
of visual monitoring records with the annual report. See new item #8 in Part 7.6 of the draft 2026
PGP.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

7.7 Annual Reporting for Any Decision-maker with Discharges of Pollutants to Waters of

the United States Containing NMFS Listed Resources of Concern, as Defined in

Appendix A of the Permit, and Who is a Small Entity

Any Decision-maker who is required to submit an NOI for discharges of pollutants to
waters of the United States containing NMFS Listed Resources of Concern, as defined in
Appendix A of the PGP, and is a small entity, as defined in Appendix A of the PGP, must submit
an annual report to EPA. Large entities with discharges of pollutants to waters of the United
States containing NMFS Listed Resources of Concern are required to submit annual reports
consistent with Part 7.6 of the PGP. Decision-makers must submit the annual report
electronically through EPA's NPDES eReporting Tool (NeT), available at
https://www.epa.gov/npdes/pesticide-permitting. unless NeT is otherwise unavailable or the
Decision-maker meets the waiver requirements for submitting a paper annual report. Decision-
makers waived from the requirement to use NeT for annual report submission must certify on the
paper annual report submitted to EPA the rationale for eligibility to use the waiver. The annual
report must be submitted to EPA Headquarters (either through NeT or if NeT is otherwise
unavailable or the Decision-maker meets the NeT waiver requirement, to the EPA Headquarters
address identified in Part 8.1 of the PGP) no later than February 15 of the following year for all
pesticide activities covered under this permit occurring during the previous calendar year.

Annual reporting requirements begin with those activities occurring during calendar year 2027.
NOTE: EPA is proposing the same ESA procedures for FWS under the draft 2026 PGP as
described here for NMFS. Any Decision-maker who is required to submit an NOI for discharges
of pollutants to waters of the United States containing FWS Listed Resources of Concern and is a
small entity must submit an annual report to EPA.

When Decision-makers terminate permit coverage, as specified in Part 1.2.5 of the PGP, an
annual report must be submitted for the portion of the year up through the date of termination.
The annual report is due no later than February 15 of the next year.

For small entities, the annual report is a summary of the pest control activities for each
applicable use pattern that results in a discharge of pollutants to waters of the United States
containing a NMFS Listed Resource of Concern, as defined in Appendix A of the PGP. For
small entities, discharges of pollutants to waters that do not contain NMFS Listed Resources of
Concern do not need to be included in the annual report. The annual report must contain:

a.	Decision-maker's name and contact information;

b.	NPDES permit tracking number(s);

c.	Contact person name, title, e-mail address (if any), and phone number; and

d.	For each treatment area, report the following information:

1.	Description of treatment area, including location and size (acres or linear feet) of
treatment area and identification of any waters of the United States, either by name
or by location, to which pesticide(s) are discharged;

2.	Pesticide use pattern(s) {i.e., mosquito and other flying insects, weed and algae,
animal pest, or forest canopy) and target pest(s);

3.	Company name(s) and contact information for pesticide applicator(s), if different
from the Decision-maker;

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4. Total amount of each pesticide product applied for the reporting year by the EPA
registration number(s) and by application method (e.g., aerially by fixed-wing or
rotary aircraft, ground based spray, etc.);

5. The approximate date of any discharge of pollutants;

6. If applicable, any adverse incidents as a result of these treatment(s), for incidents, as
described in Part 6.4.1;

7. If applicable, description of any corrective action(s), including spill responses,
resulting from pesticide application activities and the rationale for such action(s);

NOTE: For the draft 2026 PGP, EPA is proposing to require Decision-makers to submit copies
of visual monitoring records with the annual report. See new item #8 in Part 7.7 of the draft 2026
PGP. EPA is also proposing the same ESA procedures for FWS under the draft 2026 PGP as
described above for NMFS. For small entities, discharges of pollutants to waters of the United
States that do not contain FWS Listed Resources of Concern do not need to be included in the
annual report.

7.8 Electronic Reporting Requirement

Any Decision-makers required to submit Notices of Intent (NOIs), Notices of Termination
(NOTs), and/or annual reports, must submit them electronically unless a waiver is granted. Part
7.8 of the PGP outlines the conditions for obtaining a waiver. The PGP requires that all NOIs,
NOTs, and annual reports be submitted electronically, unless EPA's NPDES eReporting Tool
(NeT) is otherwise unavailable or the Decision-maker has obtained a waiver from the
requirement to use the NeT. Electronic reporting improves efficiency for both Decision-makers
and EPA and allows Decision-makers to obtain authorization to discharge in a timely manner (as
is important for many pesticide applications).

In those rare cases where Decision-makers are unable to report electronically, the PGP
contains language that allows for hard copy submittal of information when the following
exemptions apply: (1) If the Decision-maker is physically located in a geographic area (i.e., zip
code or census tract) that is identified as under-served for broadband Internet access in the most
recent report from the Federal Communications Commission; or (2) If the Decision-maker has
limitations regarding available computer access or computer capability. A Decision-maker who
wishes to use paper submittals must submit a request to the EPA contact in the appropriate EPA
Regional Office listed in Part 8 of the PGP to obtain a waiver from submitting reports
electronically.

8. EPA Contact and Mailing Addresses

Part 8 of the PGP identifies contact information and mailing addresses for any applicable
reporting requirements of the PGP. Note that depending on the requirement, some
reports/notifications are to go to the EPA Regional office while others are to be sent to an EPA
Headquarters location. Generally, Regions are notified for information that may require rapid
review and response by the Region to address potential adverse effects or other concerns
requiring more immediate attention.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

9. Permit Conditions Applicable to Specific States, Indian Country, or Territories

Part 9.0 of the PGP, when finalized, will include specific permit conditions provided by
States, Territories, and Tribes as part of their Clean Water Act (CWA) Section 401 certifications
and their Coastal Zone Management Act (CZMA) concurrences.

EPA cannot issue an NPDES permit until the state, territory or tribe in which the discharge
originates certifies that the discharge will comply with applicable provisions of the CWA or
waives certification. Part 9 of the PGP identified provisions provided to EPA by States,
Territories and Tribes in their CWA § 401 certifications that the States, Territories and Tribes
deem necessary to assure compliance with applicable provisions of the CWA and any other
appropriate requirements of State, Territory and Tribal law. See 33 U.S.C. 1341(d); 40 CFR §
124.53(e)(1). Pursuant to CWA § 401(d), EPA attached those State, Territory and Tribal
provisions to the PGP; those that constitute effluent or other limitations or monitoring
requirements are enforceable conditions of the federal permit. American Rivers, Inc. v. FERC,
129 F.3d 99, 107 (2nd Cir. 1997). These conditions are subject to review in State, Territory and
Tribal administrative and judicial tribunals with appropriate jurisdiction. 40 CFR § 124.55(e);
American Rivers, Inc. v. FERC, 129 F.3d 99, 102 (2nd Cir. 1997); Roosevelt Campobello Int'l
Park Comm 'n v. EPA, 684 F.2d 1041, 1056 (1st Cir. 1982).

The Coastal Zone Management Act (CZMA) and its implementing regulations (15 CFR
Part 930) require that any Federal licensed activity directly affecting the coastal zone of a state
with an approved Coastal Zone Management Program (CZMP) be consistent with the
enforceable policies of that approved program to the maximum extent practicable. Agency
general permits that do not involve case-by-case or individualized determinations by the Agency
are federal activities for the purposes of CZMA section 307(c)(1). For the final 2026 PGP, EPA
will make a consistency determination regarding the enforceable policies in each approved state
CZM program for the coastal zones including state waters where the final 2026 PGP authorizes
discharges of pollutants. [15 CFR 930.31(d)],

10. Permit Appendices

A. Definitions and Acronyms

Appendix A of the PGP provides permit-specific definitions of statutory, regulatory, and
other terms important for understanding its requirements. Any terms that are not listed in this
definitions part have the meaning given to the terms by 40 CFR Part 122.2 (the definitions
section of the NPDES regulations). To develop these definitions, EPA has, where possible, relied
on existing definitions in other laws and regulations applicable to this universe of permittees in
order to provide consistency with those laws and provide permittees with a familiar framework.
NOTE: EPA is adding two new terms and definitions to Appendix A, 1) FWS Listed Resources
of Concern; and 2) Lands of Exclusive Federal Jurisdiction.

B. Standard Permit Conditions

Federal regulations require that all NPDES permits contain the standard permit conditions
specified in 40 CFR 122.41. Appendix B of the PGP includes all the standard permit conditions
published in federal regulations at 40 CFR §122.41.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

C. Areas Covered

As noted above, the PGP is available in those areas where EPA remains the NPDES permitting
authority for discharges from the application of pesticides to or over, including near, waters of
the United States. NPDES-authorized State issue permits elsewhere in the United States for these
types of discharges of pollutants. Appendix C of the PGP includes a list of those areas where this
EPA permit is available which includes portions of all ten EPA Regions where EPA remains the
NPDES permitting authority. NOTE: EPA is updating Appendix C of the draft 2026 PGP to add
permit numbers for all areas of Indian Country that are not covered by an EPA-approved
permitting program with authorization to issue permits in those areas, and for all Lands of
Exclusive Federal Jurisdiction. EPA wishes to emphasize that not all Federal lands or national
parks are lands of exclusive Federal jurisdiction. Rather, exclusive Federal jurisdiction is
established only under limited circumstances which include (1) where the Federal government
purchases land with state consent to jurisdiction, consistent with article 1, section 8, clause 17 of
the U.S. Constitution; (2) where a state chooses to cede jurisdiction to the Federal government;
and (3) where the Federal government reserved jurisdiction upon granting statehood. See Paul v.
United States, 371 U.S. 245, 263-65 (1963); Collins v. Yosemite Park Co., 304 U.S. 518, 529-30
(1938); James v. Dravo Contracting Co., 302 U.S. 134, 141-42 (1937); Surplus Trading
Company v. Cook, 281 U.S. 647, 650-52 (1930); Fort Leavenworth Railroad Company v. Lowe,
114 U.S. 525, 527 (1895).

D. Notice of Intent Form

Part 1.2.2 of the PGP identifies certain Decision-makers required to prepare and submit a
complete and accurate Notice of Intent (NOI) form to be authorized to discharge pollutants under
the PGP. Decision-makers must submit NOIs in accordance with the deadlines provided in Part
1.2.3 of the PGP. The NOI form provides EPA with the information necessary to determine a
Decision-maker's eligibility to discharge pollutants under this permit and enables EPA to better
match up Operators with other reporting requirements and to prioritize oversight activities.
Appendix D of the PGP contains information that is required to be provided on the NOI form.
Except in special circumstances, EPA requires that Decision-makers submit that information
electronically, using EPA's NeT available at https://www.epa.gov/npdes/pesticide-permitting.
because it is easier (including availability of online instructions and help menus to guide you
through the process), faster (NOIs can be processed 2 weeks or more faster than paper forms),
and more accurate (NeT will ensure form is completed and will auto check certain key elements
to improve accuracy of information submitted). See Part 7.8 of the PGP for waiver information.
NOTE: As noted in Part III. 1.2.2 of this fact sheet, EPA is proposing to require the submission of
the one or more six-digit North American Industry Classification System (NAICS)
codes/descriptions, if available, and the latitude and longitude of the pest management area(s).
EPA is updating the NOI form to include these fields. As noted in this fact sheet, EPA is
proposing the same ESA procedures for FWS under the draft 2026 PGP as described throughout
for NMFS. EPA is updating the NOI form to include the term, "FWS Listed Resources of
Concern" where applicable.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

E. Notice of Termination Form

Part 1.2.5 of the PGP requires certain Decision-makers {i.e., those required to submit an
NOI to be authorized under this permit) to submit a Notice of Termination (NOT) form within 30
days of the occurrence of one of several different triggering events: (1) when a new Decision-
maker has taken over responsibility for the pest control activity, (2) the Decision-maker has
ceased aquatic pesticide application covered under the general permit, (3) there is not and no
longer will be pollutant discharge, or (4) the Decision-maker has obtained coverage under an
individual permit or an alternative general permit. Appendix E of the PGP contains a copy of the
information required to be submitted on the NOT form. Like the NOI, EPA requires that
Decision-makers complete and submit the NOT form electronically using EPA's NeT available
at https://www.epa.gov/npdes/pesticide-permitting. except in specified circumstances. See Part
7.8 of the PGP for waiver information.

F. Pesticide Discharge Evaluation Worksheet

Part 7.3 of the PGP requires Decision-makers who are required to submit an NOI and are
small entities, as defined in Appendix A of the PGP, to complete and retain a worksheet for at
least 3 years from when an Operator's coverage under the PGP expires or is terminated.
Decision-makers are required to make this worksheet available to EPA, including an authorized
representative of EPA, upon requires. Appendix F of the PGP contains a copy of the worksheet
required to be retained by Decision-makers.

G. Annual Report Template

Part 7.6 of the PGP requires Decision-makers who: (1) are required to submit an NOI and
are large entities, as identified in Part 5 of the PGP; and/or (2) discharge of pollutants to waters
of the United States containing NMFS Listed Resources of Concern, to submit Annual Reports.
The Annual Report must be submitted no later than February 15 of the following year for all
pesticide activities covered under the PGP occurring during the previous calendar year. When
Decision-makers terminate permit coverage, as specified in Part 1.2.5 of the PGP, an Annual
Report must be submitted for the portion of the year up through the date of termination.

Appendix G of the PGP contains a copy of the information required to be submitted with an
Annual Report. Like the NOI and NOT, EPA requires that Decision-makers complete and submit
the Annual Report form electronically using EPA's NeT that is available for use at
https://www.epa.gov/npdes/pesticide-permitting unless eNOI is otherwise unavailable or the
Decision-maker has obtained a waiver from the requirement to use NeT for submitting the
Annual Report. See Part 7.8 of the PGP for waiver information. NOTE: As noted in Part III. 7 of
this fact sheet, EPA is proposing to require the submission visual monitoring records with the
annual report. EPA is also proposing the same ESA procedures for FWS under the draft 2026
PGP as described throughout for NMFS. EPA is updating the annual reporting form to add visual
monitoring fields and include the term, "FWS Listed Resources of Concern" where applicable.

H. Adverse Incident Report Template

Part 6.4 of the PGP requires Operators to: (1) provide oral notice to EPA within 24 hours,
and (2) submit a written report within 30 days of becoming aware of an adverse incident which
may have resulted from a discharge from the Operator's pesticide application. Adverse Incident,

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

as defined in the PGP Appendix A, is an unusual or unexpected incident that an Operator has
observed upon inspection or of which the Operator otherwise become aware, in which: (1) There
is evidence that a person or non-target organism has likely been exposed to a pesticide residue,
and (2) The person or non-target organism suffered a toxic or adverse effect. Appendix H of the
PGP contains a copy of the information required to be submitted to the appropriate EPA
Regional office and to the State Lead Agency within 30 days of discovering the adverse incident.

I. Endangered Species Procedures

The PGP specifies procedures to protect federally-listed endangered and threatened species
and its designated critical habitat. As discussed in section 1.1.2.4 of the PGP, coverage under this
permit is available only for discharges of pollutants and discharge-related activities that are not
likely to result in any short- or long-term adverse effects to species that are federally-listed as
endangered or threatened under the ESA or federally-designated critical habitat under the ESA,
except as provided in eligibility Criterion B, C and, D. For discharges of pollutants to a subset of
these resources, identified in this permit as NMFS Listed Resources of Concern, which are
defined in Appendix A of the PGP, the Operator must document that discharges of pollutants
meet these conditions by certifying eligibility under one of Criteria A-F. (Note that operators not
otherwise required to submit an NOI do not need to do so merely to certify under Criterion A,
which indicates that discharges of pollutants will not occur to waters of the U.S. where NMFS
Listed Resources of Concern are present.) Appendix I contains a four-step process that must be
followed for determining whether an Operator is eligible for permit coverage, prior to submittal
of the NOI. In order to become eligible for this permit, each Operator must determine its
compliance with one of six eligibility criteria (A - F). If Operators cannot determine if they meet
one of the eligibility criteria related to NMFS Listed Resources of Concern, the Operator cannot
submit an NOI to gain coverage under the PGP. In these instances, the Operator may consider
applying to EPA for an individual NPDES permit. NOTE: As noted throughout this fact sheet,
EPA is proposing the same ESA procedures for FWS under the draft 2026 PGP as described
above for NMFS. EPA has updated Appendix I of the PGP to include FWS Listed Resources of
Concern and added a worksheet to help Operators with ESA eligibility criterion selection.

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

IV. Fact Sheet Appendices

APPENDIX A. List of Pesticides and Degradates Which Exceeded Aquatic-life
Benchmarks in the USGS 2021 Study.

Table Al. Sites that exceed one or more aquatic-life benchmarks in the last five years (2013-2017) USGS 2021

Pcsticidc/Dcgradatc

Total number of sites that exceed one or more
aquatic-life benchmarks

Acetochlor

Atrazine

Carbaryl

Chlorimuronethyl

Chlorpyrifos

Diazinon

Dichlorvos

Dicrotophos

Diuron

Fipronil

Halosulfuronmethyl

Imidacloprid

Linuron

Metolachlor

Metribuzin

Simazine

Tebupirimfos

Table A2. Percentage of sites that exceed one or more aquatic-life benchmarks in the last five years (2013-
2017) in the USGS 2021 study.

Pcsticidc/Dcgradatc

Percentage of total sites that exceed one or more aquatic-life benchmarks

Acetochlor

Atrazine

Carbaryl

2.7

Chlorimuronethyl

2.7

Chlorpyrifos

2.7

Diazinon

1.4

Dichlorvos

Dicrotophos

1.4

Diuron

1.4

Fipronil

9.5

Halosulfuronmethyl

2.7

Imidacloprid

Linuron

1.4

Metolachlor

Metribuzin

1.4

Simazine

1.4

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

Tebupirimfos

1.4

95

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U.S. Environmental Protection Agency Draft 2026 NPDES Pesticide General Permit Fact Sheet

APPENDIX B. Regulatory Status and Chemical-specific Mitigation Measures for Pesticide
Active Ingredients with at Least One Aquatic Life Benchmark Exceedances in the USGS
2021 Study.

Seventeen pesticides in the USGS 2021 study were observed at concentrations that exceeded at
least one EPA aquatic life benchmark: 9 herbicides (acetochlor, atrazine, linuron, metalochlor,
diuron, metribuzin, simazine, chlorimuron-ethyl, and halosulfuron-methyl) and 8 insecticides
(dichlorvos, fipronil, imidacloprid, carbaryl, chlorpyrifos, diazinon, dicrotophos, and
tebupirimfos).

Chemical

Recent Actions

Acetochlor

An Interim Registration Review Decision (ID) for acetochlor was published in
September of 202110 The ID required acetochlor product labels to be updated with
mitigation measures including mandatory spray drift reduction language, and
advisory statements to protect surface water, groundwater, and non-target organisms.

Atrazine

An Interim Registration Review Decision for atrazine was published in September of
2020. The ID required atrazine product labels to be updated with mitigation measures
including use rate reductions and personal protective equipment for certain
formulations and uses, prohibition of certain application methods, mandatory spray
drift reduction language, and the implementation of an atrazine stewardship program
to reduce runoff and spray drift to aquatic environments. In October 2020, EPA
received a petition alleging that the agency violated its duties under FIFRA by issuing
the atrazine ID without substantial evidence supporting the decision. In 2021, EPA
sought and was granted a voluntary partial remand from the Ninth Circuit Court of
Appeals, which provided the agency the opportunity to reevaluate the policy decision
to use 15 |ig/L as the level of regulation for aquatic plant communities. In June 2022,
EPA proposed additional mitigation to protect aquatic plant communities including
prohibition of application when soils are saturated or above field capacity, prohibition
of application during rain, prohibition of aerial applications, reduced annual
application rates in sorghum, field corn, and sweet corn. In addition to the measures
listed above, EPA is proposing to add a mitigation menu to labels that would require
growers to select a combination of application rate reductions and/or runoff control
measures to further mitigate potential risks to aquatic plant communities. A FIFRA
Scientific Advisory Panel convened in August 2023 to assist in the analysis and
assessment of ecological risk from atrazine use. EPA will consider comments on the
proposed revisions to the ID and conclusions from the SAP to continue registration
review.

Carbaryl

Lawn broadcast uses of liquid formulations cancelled; certain other uses and
application methods cancelled; reduced application rates for some uses; prohibit most
aerial applications (2003 IRED). Carbaryl is currently undergoing Registration
Review and a Proposed Interim Registration Review Decision (PID) with potential
mitigation measures was published in December 2022 for a 75-day public comment
period.

Chlorimuron-ethyl

An Interim Registration Review Decision was issued in June 2017. The ID required
product labels to be updated with mandatory spray drift mitigation including medium
or coarser droplet size for most uses, application height restrictions, and wind speed
restrictions.

10 For a current Registration Review schedule, please go to: https://www.epa.gov/pesticide-
reevaluation/registration-review-schedules

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

Chemical

Recent Actions

Chlorpyrifos

A Proposed Interim Decision for chlorpyrifos with potential mitigation measures was
published in December 2020 for a 60-day public comment period. In August 2021,
EPA issued a final rule revoking all tolerances for chlorpyrifos use on food crops. In
June 2022 following a consultation with EPA, a National Marine Fisheries Service
(NMFS) Biological Opinion (BiOp) for chlorpyrifos was issued which specifies
agreed-upon mitigation measures including the prohibition of wide-area outdoor uses
(other than as a mosquito adulticide), application buffers to waterbodies, instructions
to prevent runoff to aquatic habitats, ecological incident reporting, and statements
providing resources for the protection of endangered species. EPA plans to issue
revised labels for chlorpyrifos by December 2023, which will include mitigation
measures specified in the BiOp and limit uses to non-food agriculture and forestry,
indoor insect baits, commercial and industrial facility pest control and limited
commercial and golf turf use. Chlorpyrifos is currently undergoing Registration
Review.

Diazinon

In June 2022 after consultation with EPA, NMFS (National Marine Fisheries Service,
or, NOAA Fisheries) issued a Biological Opinion reaching a "no jeopardy [to
endangered species]" determination for the continued registration of diazinon, based
on mitigation measures that were identified during the consultation process. The final
BiOp specifies agreed-upon mitigation measures including prohibition of aerial
application, mandatory spray drift reduction measures, buffer zones to water bodies,
ecological incident reporting, and statements providing resources for the protection of
pollinators and endangered species. Additionally in March 2023, registrants of
diazinon agreed to work with EPA take early action to implement measures
protecting farmworkers and other handlers from potential health risks associated with
occupational exposure to diazinon. EPA plans to issue updated labels for diazinon
reflecting the changes resulting from the Biological Opinion and the worker
protection measures by December of 2023. Diazinon is currently undergoing
Registration Review.

Dichlorvos (DDVP)

Dichlorvos is currently undergoing Registration Review. Potential mitigation
measures for dichlorvos will be presented for public comment in an anticipated
Proposed Interim Decision.

Dicrotophos

Dicrotophos is currently undergoing Registration Review. Potential mitigation
measures for dicrotophos will be presented for public comment in an anticipated
Proposed Interim Decision.

Diuron

A Proposed Interim Decision for diuron with potential mitigation measures was
published in August 2022 for a 60-day public comment period. Diuron is currently
undergoing Registration Review.

Fipronil

Fipronil is currently undergoing Registration Review. A revised Draft Ecological
Risk Assessment for fipronil was completed in 2021. Potential mitigation measures
for fipronil will be presented for public comment in an anticipated Proposed Interim
Decision.

Halosulfuron-methyl

An Interim Registration Review Decision was issued in June 2017. The ID required
product labels to be updated with mandatory spray drift mitigation including medium
or coarser droplet size for most uses, application height restrictions, and wind speed
restrictions.

Imidacloprid

Imidacloprid is currently undergoing Registration Review. Potential mitigation
measures for imidacloprid will be presented for public comment in an anticipated
Proposed Interim Decision.

Linuron

An Interim Registration Review Decision for linuron was published in August 2020.
The ID for linuron included required label mitigation to protect workers and
bystanders including certain use deletions, application rate reductions, additional
personal protective equipment, and increased re-entry intervals for applicators. The
decision also included ecological mitigation to protect fish, aquatic invertebrates, and

97

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

Chemical

Recent Actions



plants including mandatory and advisory spray drift reduction measures, and non-
target organism advisory statements.

Metolachlor

An Interim Registration Review Decision for metolachlor and S-metolachlor was
published in March 2021. The ID included advisory label mitigation for groundwater
and surface water to reduce leaching and runoff exposure to drinking water and to
non-target aquatic plants. The decision also included mandatory spray drift reduction
language to reduce exposure to aquatic plants via drift deposition.

Metribuzin

Metribuzin is currently undergoing Registration Review. Potential mitigation
measures for metribuzin will be presented for public comment in an anticipated
Proposed Interim Decision.

Simazine

An Interim Registration Review Decision for simazine was published in September
2020. The ID included label mitigation featuring mandatory spray drift reduction
language to reduce exposure to aquatic plants via drift deposition.

Tebupirimfos

Tebupirimfos (phostebupirim) is currently undergoing Registration Review. Potential
mitigation measures for tebupirimfos will be presented for public comment in an
anticipated Proposed Interim Decision.

98

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

APPENDIX C. 303(d) Impairment Example - CA Central Valley Regional 303(d)
Impairment List of Pesticides.

Pesticides/Degradates that are listed as 303(d) impairments from the CA Central Valley (USEPA Approved 2020-
2022 list)

Note: This table includes pesticides that have been cancelled.

Pesticide/Degradate

#of

impairments

WQS being exceeded

Aldicarb

1

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the 48-hr LC50 value for Chironomus tentans (20
Hg/L).

Azinphos-methyl (Guthion)

3

Narrative pesticide objectives, interpreted using the USEPA
National Recommended Water Quality Criteria (NRWQC)
for freshwater aquatic life protection (instantaneous
maximum, 0.01 ng/L) (USEPA, 1976).

Bifenthrin

29

Narrative toxicity and pesticide objectives, interpreted using
one tenth the 96-hour LC50 value for Haylella azteca (0.43
|ig/g): the chronic concentration goal (4-day average, 0.1
ng/LA); and the UC Davis Aquatic Life Criterion (4-day
average, 0.0006 |ig/L) not to be exceeded more than once
every three years on average.

Chlordane

4

Narrative toxicity and pesticide objectives, interpreted using
the Office of Environmental Health Hazard Assessment
(OEHHA) Fish Contaminant Goal (FCG) (5.6 ng/kg); the
modified OEHHA FCGs for fish tissue (3.9 ppb) and
shellfish tissue (6.0 ppb); the probable effect concentration
in freshwater sediments (17.6 |ig/kg) (MacDonald et al.,
2000a); and the National Academy of Science (NAS)
guidelines for protection of aquatic life from
bioaccumulation of toxic substances (100 ng/kg) (NAS,
1972).

Chlorpyrifos

52

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (1.77 |ig/g):
the California Department of Fish and Wildlife (CDFW)
Hazard Assessment Criteria for freshwater aquatic life
protection (1-hour average, 0.025 |ig/L and 4-day average,
0.015 |ig/L) not to be exceeded more than once every three
years (CDFW, 2000); the NRWQC for freshwater aquatic
life protection (4-day average, 0.014 |ig/L): the modified
OEHHA FCG for shellfish tissue (1,000 ppb) and the
USEPA Health Advisory 2011 criteria for freshwater (2.0
Hg/L).

Cyfluthrin

13

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (1.1 |ig/g): the
chronic concentration goal (4-day average, 0.2 ng/LA); and
the UC Davis Aquatic Life Criterion (4-day average,
0.00005 |ig/L) not to be exceeded ore than once every three
years on average.

Cyhalothrin, Lambda

12

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (0.44 |ig/g):
the chronic concentration goal (4-day average, 0.3 ng/LA);

99

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

Pesticide/Degradate

#of

impairments

WQS being exceeded





and the UC Davis Aquatic Life Criterion (4-day average,
0.0005 ug/L).

Cypermethrin

10

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (0.3 |ig/g):
and the chronic concentration goal (4-day average, 0.3
ng/LA).

DDD

1

Narrative pesticide objectives, interpreted using the
probable effect concentration for Sum DDD (o,p' + p,p')
(28 ng/kg) (MacDonald et al., 2000a). California Toxics
Rule (CTR) for human health protection for fish only
consumption (30-day average, 0.00084 |ig/L). CTR for
human health protection for water & fish consumption for
DDD (30-day average, 0.00059 |ig/L).

DDE

12

Narrative toxicity and pesticide objectives, interpreted using
the probable effect concentration for Sum DDE (31.3 |ig/kg)
(MacDonald et al., 2000a). CTR for human health
protection for fish only consumption (30-day average,
0.00084 |ig/L). CTR for human health protection for water
& fish consumption (30-day average, 0.00059 ug/L).

DDT

23

Narrative toxicity and pesticide objectives, interpreted using
the probable effect concentrations for total DDT (572
|ig/kg) and the sum of DDT (62.9 |ig/kg) (MacDonald et al.,
2000a); the NAS guidelines for protection of aquatic life
from bioaccumulation of toxic substances (1,000 |ig/kg)
(NAS, 1972); the 2008 OEHHA FCG (21 ng/kg); the
OEHHA Screening Value (100 ng/g); and the modified
OEHHA FCG for fish tissue (15 ppb). CTR for freshwater
aquatic life protection (4-day average, 0.001 |ig/L). (CTR,
2000). CTR for human health protection for water & fish
consumption and fish only consumption (30-day average,
0.00059 (ig/L) (CTR, 2000). USEPA NRWQC for human
health protection for water & fish consumption (0.00022
Ug/L).

Total DDT (sum of 4,4'- and
2,4'- isomers of DDT, DDE,
and DDD)

3

Narrative pesticide objectives, interpreted using the CTR for
freshwater aquatic life protection (4-day average, 0.001
Ug/L) (CTR, 2000); the modified OEHHA FCGs for fish
tissue (15 ppb) and shellfish tissue (23 ppb); and the NAS
guidelines for protection of aquatic life from
bioaccumulation of toxic substances (1,000 ug/kg) (NAS,
1972).

Deltamethrin

5

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (0.79 |ig/g):
and the USEPA Aquatic Life Benchmark for acute toxicity
in invertebrates (0.0041 ug/L).

Diazinon

27

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the LC50 value for Hyalella Azteca (11 ug/gK the
CDFW Hazard Assessment Criteria for freshwater aquatic
life protection (1-hour average, 0.160 ug/L and 4-day
average, 0.100 ug/L) not to be exceeded more than once
every three years; the modified OEHHA FCG for shellfish
tissue (2,300 ppb).

100

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

Pesticide/Degradate

#of

impairments

WQS being exceeded

Dichlorvos

1

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the 96-hour LC50 value for Daphnia magna
(0.085 ug/L).

Dieldrin

11

Narrative toxicity and pesticide objectives, interpreted using
the probable effect concentration of 61.8 ng/kg (MacDonald
et al., 2000a); the OEHHA 2008 FCG (0.46 ng/kg); the
modified OEHHA FCGs for fish tissue (0.32 ppb) and
shellfish tissue (0.49 ppb); NAS guidelines for protection of
aquatic life from bioaccumulation of toxic substances (100
|ig/kg) (NAS, 1972). CTR for human health protection for
water & fish consumption (30-day average, 0.00014 |ig/L)
(CTR, 2000). CTR for freshwater aquatic life protection (4-
day average, 0.056 ug/L) (CTR, 2000).

Dimethoate

4

Narrative toxicity and pesticide objectives, interpreted using
one-tenth of the LC50 value for Cyclops strenuous; one-
tenth of the 96-hour LC50 value for Pteronarcys
californica; the California Department of Public Health
Notification level for drinking water (1 |ig/L): and the
USEPA Aquatic Life Benchmark for acute toxicity in
invertebrates (0.5 ug/L).

Disulfoton

1

Narrative toxicity and pesticide objectives, interpreted using
the USEPA NRWQC for freshwater aquatic life protection
(instantaneous maximum, 0.05 ug/L) (USEPA, 1973).

Diuron

12

Narrative toxicity and pesticide objectives, interpreted using
the 96-hour EC50 value for Chlorellapyrenoidosa (1.3
Ug/L); and the UC Davis Aquatic Life Criteria (4-day
average, 1.3 ug/L). not to be exceeded more than once every
three years on average.

Esfenvalerate/Fenvalerate

4

Narrative toxicity and pesticide objectives, interpreted using
one-tenth of the LC50 value for Hyalella Azteca (1.5 ug/gK
the chronic concentration goal for esfenvalerate (4-day
average, 0.3 ng/LA); one-tenth of the 96-hour LC50 value
for Pimemphales promelas for fenvalerate (1.13 ug/L).

Fipronil

5

Narrative pesticide objectives, interpreted using the USEPA
Aquatic Life Benchmark for chronic toxicity in
invertebrates (0.011 ug/L); and one-tenth of the LC50 value
for Hyalella azteca (0.13 ug/g)-

Fipronil Sulfone

4

Narrative pesticide objectives, interpreted using the USEPA
Aquatic life Benchmark for chronic toxicity in invertebrates
(7-day average, 0.037 ug/L).

Group A Pesticides

19

Unspecified. USEPA NRWQC for human health protection
for water & fish consumption (0.0026 ug/L).

Hexachlorobenzene/ HCB

1

The CTR for human health protection for water & fish
consumption (30-day average, 0.00075 ug/L).

Imidacloprid

9

Narrative toxicity objectives, interpreted using the UC
Davis Water Quality Criteria for aquatic life (4-day average,
0.016 ug/L).

Lindane/ gamma
Hexachlorohexane (gamma
HCL)

1

Narrative toxicity and pesticide objectives.

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

Pesticide/Degradate

#of

impairments

WQS being exceeded

Linuron

11

Narrative toxicity objectives, interpreted using the USEPA
Aquatic Life Benchmark for acute toxicity in invertebrates
(0.09 ug/L).

Malathion

5

Narrative toxicity and pesticide objectives, interpreted using
the USEPA NRWQC for freshwater aquatic life protection
(instantaneous maximum, 0.1 |ig/L [USEPA 1976] and 1-
hour average, 0.43 |ig/L [CDFG, 1998]); the UC Davis 4-
day average Aquatic Life Criteria (0.028 ug/L): and one-
tenth the 96-hour LC50 value for the most sensitive species.

Methyl Parathion

1

Narrative toxicity and pesticide objectives, interpreted using
the CDFW Criterion for freshwater aquatic life protection
(0.08 ug/L) (CDFW, 1992).

Metolachlor

3

Narrative toxicity objectives, interpreted using the USEPA
Aquatic Life Benchmark for chronic toxicity in
invertebrates (1 ug/L).

Oxyfluorfen

2

Narrative toxicity and pesticide objectives, interpreted using
the 96-hour EC50 value for Selenastrum capricornutum
(0.29 ug/L).

Paraquat

1

Narrative toxicity objectives, interpreted using the USEPA
Aquatic Life Benchmark for acute toxicity in nonvascular
plants (0.396 ug/L).

Permethrin

6

Narrative toxicity and pesticide objectives, interpreted
using: one-tenth the LC50 value for Hyalella azteca (8.9
|ig/g): CDFW Criterion for freshwater aquatic life
protection (0.03 ug/L) (CDFW, 2000); chronic
concentration goal (4-day average, 1 ng/ LA); and UC
Davis 4-day average Aquatic Life Criterion (0.002 ug/L, not
to be exceeded more than once every three years on
average).

cis-Permethrin

1

Narrative toxicity and pesticide objectives, interpreted using
one-tenth the 24-hour LC50 value for Tanytarsus sp. (0.033
Ug/L).

Pesticides

2

Unspecified

Prometryn

1

Narrative toxicity and pesticide objectives, interpreted using
the 96-hour EC50 value for Navicula pelliculosa (1 ug/L).

Pyrethroids

31

Narrative toxicity and pesticide objectives, interpreted using
the summed ratios of the pyrethroid pesticides (bifenthrin,
cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin,
permethrin) and their respective chronic concentration
goals.

Simazine

2

Narrative toxicity objectives, interpreted using the USEPA
acute Aquatic Life Benchmark for nonvascular plants (6
Ug/L). Drinking Water Standards - Primary Maximum
Contaminant Limit (MCL) (4 ug/L).

Toxaphene

2

Narrative toxicity objectives, interpreted using the OEHHA
Screening Value (30 ng/g) (Brodberg & Pollock, 1999).
CTR for freshwater chronic aquatic life protection (4-day
average, 0.0002 ug/L) (CTR, 2000).

Trifluralin

1

Narrative toxicity and pesticide objectives, interpreted using
the LOEC for Pimephalespromelas (0.7 ug/L) (USEPA,
2008).

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APPENDIX D. Cost Impacts and Number of Entities Covered

The potential incremental costs that may be associated with this permit are expenditures above
those required for existing regulations and current practices (i.e., baseline conditions) up to
compliance with the permit. EPA projects that this permit will result in minimal incremental cost
impacts on regulated entities because the requirements in the permit are largely the same as those
found in the EPA's previously issued PGPs. See Part I of this fact sheet for the list of proposed
changes under this permit.

EPA estimates that the majority of the proposed changes under this permit will result in no
incremental cost impacts. For example, proposed requirements to clarify visual monitoring are
reiterating and/or reemphasizing existing requirements. See discussion in Part III regarding
adding Parts 4.3 and 4.4 and reemphasizing the monitoring records in Part 7. Two of the
proposed changes are to require certain Operators to submit their Pesticide Discharge
Management Plan (PDMP) and visual monitoring records to EPA instead of keeping them on
site. See discussion in Part III. 5 and Part III. 7 of this fact sheet. Several proposed changes are
administrative or requirements under the NPDES Reporting Rule. See discussion in Part III. 1.2.2
on NOI contents and see changes in Part III. 10. A, Definitions and Acronyms, and Part III. 10.C,
Areas Covered.

Although visual monitoring has been a requirement since the first PGP, Operators were not
required to document the procedures to be used for visual monitoring. Therefore, the proposed
change to require documentation of visual monitoring procedures in the PDMP may increase
incremental cost for Operators who are required to develop the plan. See discussion in Part III.5
for this proposed change.

The remaining proposed changes under this permit are related to the ESA consultation with
FWS. EPA is proposing the same ESA procedures for FWS that have previously existed in the
permit for NMFS. As such, there are no changes to the incremental cost associated with these
changes.

For background on cost impacts under the PGP, see the economic analysis and cost analysis
conducted for the previously issued PGPs:

• "Economic Analysis of the Pesticide General Permit (PGP) for Point Source Discharges
from the Application of Pesticides" for the 2011 PGP in the docket at EPA-HQ-OW-
2010-0257-0151.

• "Cost Impact Analysis for the EPA 's 2016 Pesticide General Permit (PGP) " in the
docket at EPA-HQ-OW-2015-0499

• "Appendix D. Cost Impacts and Number of Entities Covered" in the Final 2021 PGP Fact
Sheet at EPA-HQ-OW-2020-0005

As shown in Table 1, EPA estimates that this PGP will cover approximately 14,300 Operators
based on the economic analysis for the 2011 PGP. EPA continues to estimate that a total of
365,000 Operators across the U.S. will be covered under both state-issued and federal NPDES
PGPs together.

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Table 1: Estimate of Entities Coverec

Under the Draft 2026 PGP

State/Tribe Not
Authorized for
NPDES

Mosquito
and Other
Flying Insect
Pest Control

Weed and
Algae Pest
Control

Animal Pest
Control

Forest
Canopy Pest
Control

Total

Massachusetts

2,153

214

2,402

New Hampshire

642

781

New Mexico

10,285

10,332

District of
Columbia

Territories

314

357

Tribes

169

Federal Facilities

245

Total

150

13,560

174

413

14,297

This permit specifies procedures to assist in protecting federally-listed endangered and
threatened species and federally designated critical habitats under the Endangered Species Act
(ESA). These procedures are carried forward from EPA's previously issued PGPs and only apply
to Decision-makers in the limited areas where NMFS Listed Resources of Concern, as defined in
Appendix A of the PGP, are present. EPA is proposing under this permit the same ESA
procedures for FWS as for NMFS. With this proposed change, there may be shift in the number
of potentially affected entities that may now incur costs solely because of discharges of
pollutants to waters of the United States containing FWS Listed Resources of Concern.

EPA estimated 714 potentially affected entities which overlap with NMFS Listed Resources of
Concern for the 2011 PGP. As in the 2011 PGP, these are potentially affected entities who may
(in addition to other costs as a result of the permit) incur costs solely because of discharges of
pollutants to waters of the United States containing NMFS Listed Resources of Concern.
Similarly, with the proposed change, potentially affected entities may incur costs solely because
of discharges of pollutants to waters of the United States containing FWS Listed Resources of
Concern. EPA continues to estimate that less than 2 percent of the total number of Operators
would need to meet additional permit requirements beyond those in the PGP's ESA related
provisions. Two percent of 14,300 is 286. Under the 2016 PGP, EPA received less than 50 NOIs,
and under the 2021, slightly fewer, that included areas which overlap with NMFS Listed
Resources of Concern. EPA is not changing the estimated potentially affected entities value
(2%), as any additional potential entities are captured in that value based on actual data.

EPA acknowledges the difficulty of developing definitive estimates of entities and activities
potentially covered under this permit and points to two main limitations of the available data.
First, no direct source of information exists on the number of Applicators or patterns of
application for aquatic pesticides. As a result, EPA needed to derive its estimates from secondary
sources of information, and in some cases, it needed to make a variety of assumptions. Second,

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

the CWA does not define the terms "application" or "applicator" as it relates to discharges from
pesticide applications, so available data may not all use similar definitions of these terms.

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APPENDIX E. Environmental Justice Considerations

Executive Order 12898 (59 FR 7629, February 16, 1994), Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income Populations, and Executive
Order 14096 (88 FR 25251, April 21, 2023), Revitalizing Our Nation's Commitment to
Environmental Justice for All, direct each federal agency to "make achieving environmental
justice part of its mission by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of its programs, policies, and activities on
minority and low-income populations." EPA strives to enhance the ability of overburdened
communities to participate fully and meaningfully in the permitting process for EPA-issued
permits, including NPDES permits. "Overburdened" communities can include minority, low-
income, tribal, and indigenous populations or communities that potentially experience
disproportionate environmental harms and risks.11 As part of an Agency-wide effort, where
appropriate, EPA will consider implementing enhanced public involvement and outreach
opportunities for EPA-issued permits where facilities discharge to waters in overburdened
communities. EPA will establish appropriate permit terms and conditions to address
environmental justice concerns to the extent supported by the relevant information, and
consistent with and as permitted by applicable federal statutory and regulatory requirements.
Where EPA is unable to address community concerns in EPA permit terms and conditions, EPA
will identify other federal, state, or local agencies, or other entities who may be able to assist. For
more information, please visit https://www.epa.gov/environmentaliustice/ei-2020-action-agenda-
epas-environmental-iustice-strategy

As part of the general permit development process, EPA reviews available information to
evaluate whether issuance of a permit could affect overburdened communities. EPA's PGP is
available only for areas and activities where EPA is the permitting authority. Under the current
permit, Operators that are small entities12 are not required to submit an NOI. Other Operators are
required to submit NOIs to seek coverage under the permit. Even for Operators that are required
to submit an NOI, EPA has not required Operators to submit locational data in the NOI that can
be accessed through a geographical information system. EPA's rationale for this decision can be
found in the 2011 PGP Response to Comments.13 Operators have provided qualitative
information on pest management area locations by describing the areas in their NOI or by
attaching a map to their NOI. Furthermore, the initial system EPA used in 2011 to collect NOIs
did not have the functionality to accept more advanced data. EPA developed NeT to collect NOIs
for the 2021 PGP with the goal to address locational data in the 2026 PGP. Thus, the quantity of
NOIs and the information submitted as part of the current NOIs present a challenge in the limited
amount of and format of information EPA currently has available to perform a geographic
specific analysis related to communities with environmental justice concerns. However, the PGP
has requirements to ensure the protection of water quality regardless of whether a covered
discharge occurs near an overburdened community. The permit requires compliance with all

11 https://www.epa.gov/environmentaliustice/ei-2020-glossarv

12 Small Entity - any (1) private enterprise that does not exceed the Small Business Administration size standard as
identified at 13 CFR 121.201, or (2) local government that serves a population of 10,000 or less.

13 https://www.regulations.gov/document/EPA-HO-OW-2010-Q257-1277

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water quality standards and Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) labels.
There are requirements that limit where and how Operators apply pesticides in certain
waterbodies. Additionally, EPA has no evidence of water quality problems under EPA's PGP
(See the WQBEL discussion in Part III of this fact sheet for additional information). Therefore,
EPA has determined that a more in-depth environmental justice analysis is not feasible for this
permit reissuance.

For the 2026 PGP, EPA is proposing for public comment changes that will require Operators to
provide EPA with more accessible locational information for future EJ analyses. See the list of
changes summarized in Part I, and further explanations of those changes discussed in the
corresponding parts in this fact sheet. If these changes were to be finalized, EPA could utilize the
NOI's received under the 2026 PGP to obtain and evaluate information about pesticide
applications that occur in or near communities with environmental justice concerns and consider
taking additional steps, where appropriate in future permits.

EPA encourages Operators to review (and to consider adopting, where appropriate) "Promising
Practices for Permit Applicants Seeking EPA-Issued Permits: Ways to Engage Neighboring
Communities" ("Promising Practices") (see

https://www.federalregister.gOv/articles/2013/05/09/2013-10945/epaactivities-to-promote-
environmental-iustice-in-the-permit-application-process#p-104). As described in Promising
Practices,14 EPA encourages applicants for EPA-issued permits to engage in public outreach to
the neighboring communities whenever the facility's pollutant releases have—or are perceived
by a community to have—potential health and environmental impacts on overburdened
communities. In such cases, the permit applicant would have an opportunity to inform the
neighboring community about the facility's actual pollutant releases and impacts. Providing
specific information about the pollutant(s) and related health impacts of a permit action may
allay general concerns community members have about the facility or educate it about other
sources of exposure. A permit applicant that ignores a neighboring community's concerns about
pollutant discharges from its facility or general concerns about pollutant discharges in the
community may experience delays in the permitting process, negative publicity, and community
distrust. Employing promising practices can foster a dialogue between the permit applicant and
community members to prevent misunderstandings and possibly opposition to the permit. The
permit applicant can tailor the engagement of the neighboring community to be proportionate to
the actual health and environmental impacts of the facility or the particular concerns of
community members.

14 Examples of promising practices include thinking ahead about a community's characteristics, the effects of the
permit on a community, engaging the right community leaders, providing progress or status reports, providing
informational materials translated into languages appropriate for a given community, and setting up a hotline for
community members to voice concerns or request information.

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APPENDIX F. EPA's Consideration of the Regulatory Criteria in §122.28(b)(2)(v)

EPA's consideration of the regulatory criteria in §122.28(b)(2)(v) is as follows based on
information collected in the 2011 PGP development:

Type and Expected Nature of Discharge

All discharges of pollutants that would be authorized by the PGP involve either
(1) applications made directly into or over waters of the United States to control pests in or over
the water, or (2) applications to control pests near the water's edge such that pesticides will be
unavoidably deposited into waters of the United States. The PGP is structured by pesticide use
patterns. These use patterns were developed to include discharges of pollutants that are similar in
type and nature, and therefore represent the type of discharges of pollutants and expected nature
of the discharges of pollutants covered under this permit. The PGP covers the four use patterns
described in Part III. 1.1 of this fact sheet. EPA evaluated each use pattern independently with the
goal of identifying the significant activities resulting in discharges of pollutants that should be
covered under the PGP.

Potential for Toxic and Conventional Pollutants in the Discharge

EPA does not expect the potential for toxic and conventional pollutants in the discharges
from pesticides to vary among use patterns. EPA would expect, however, that the potential for
impacts from high concentrations of toxic or conventional pollutants in the discharge would be
smaller when fewer acres or linear feet are treated.

Expected Volume of Discharge

EPA also considered the expected volume of discharges of pollutants from each use
pattern. It is difficult to estimate the expected volume of discharges of pollutants for each use
pattern because Pest Management Measures used by Operators to meet the permit's technology
based effluent limitations may vary based on site-specific conditions. For example, the volume
of the discharge may vary depending on the specific pesticide being used, the intensity of the
pest pressure based on the specific pest problem, and the pest management strategy deemed to be
most effective for the pest problem. Moreover, minimizing the discharge of pollutant necessary
to manage pests successfully will vary among Operators depending on which Pest Management
Measures the Operator uses. Nonetheless, EPA expects that, in general, the volume of the
discharge will vary proportionally with the number of acres and linear miles treated.

Other Means to Identify Discharges of Pollutants

EPA also considered other means of identifying types of discharges of pollutants covered
by this permit. EPA may be able to identify pollutant discharges from Operator-submitted data,
ambient water sampling data, and other information submitted by pollutant dischargers pursuant
to federal or state law. However, EPA recognizes that the availability and quality of these data
may be limited and highly variable across the scope of activities and areas covered under the
PGP.

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Number of Discharges of Pollutants

Lastly, EPA considered the estimated number of discharges of pollutants to be covered by
the permit. While the exact number of entities and thus the number of discharges of pollutants
that may be covered by the permit is unknown, a large majority represent dischargers performing
small pesticide applications that EPA considers to have very low potential for impact. Thus,
requiring an NOI from all dischargers would be a large burden of little value for permitting
authorities and permittees alike. See Appendix D of this fact sheet for discussion on the universe
of Operators covered under this permit.

In analyzing these regulatory criteria, the Agency gave particular weight to the expected volume
of the discharges of pollutants and the estimated number of discharges of pollutants to be
covered by the permit. After considering the universe of entities to be covered under the permit,
EPA found a logical break between entities applying pesticides to larger areas versus smaller
areas, and a difference between the types of entities generally responsible for performing such
pest control activities. As a result, NOI requirements are based on the size of areas treated and
the entity making the decision to perform pesticide applications. In addition, EPA identified a
need for additional information for any discharges of pollutants to outstanding national resource
waters (Tier 3 waters) and to waters of the United States containing NMFS Listed Resources of
Concern, as defined in Appendix A of the PGP, and is including NOI requirements for all
discharges of pollutants to these waters as well. NOTE: EPA is proposing the same ESA
procedures for FWS under the draft 2026 PGP as described above for NMFS. EPA expects that
additional information is needed for any discharges of pollutants to waters of the United States
containing FWS Listed Resources of Concern.

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U.S. Environmental Protection Agency	Draft 2026 NPDES Pesticide General Permit Fact Sheet

This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

APPENDIX G. EPA's Rationale for Requiring NOIs

A detailed discussion of EPA's rationale for requiring NOIs for the following categories of
Decision-makers:

NOIs for Decision-Makers Exceeding an Annual Treatment Area Threshold

During the 2011 PGP development, EPA developed annual treatment area thresholds for
each use pattern that will only require larger Operators applying pesticides to larger areas to
submit an NOI. To determine the appropriate annual treatment area thresholds that would trigger
the NOI requirement, EPA's Office of Water, Office of Chemical Safety and Pollution
Prevention and the ten EPA Regional Offices engaged in discussions with USD A, states as co-
regulators, and representatives from industry including pesticide registrants, applicators, and land
managers. Based on these discussions, the comments received during the 2011 PGP
development, and EPA's best professional judgment, EPA developed annual treatment area
thresholds that establish NOI requirements for applications to larger areas, which are believed to
have the greatest potential for impact to waters of the United States. EPA recognizes there are
many unknowns concerning the size, organization, and activities of the permitted universe.
Considerable variation in the availability of data and in the consistency of requirements across
regions and states resulted in EPA relying heavily on its best professional judgment in setting the
NOI annual treatment area thresholds for each of the use patterns. If a Decision-maker, otherwise
not required to submit an NOI, anticipates it will exceed an applicable annual treatment area
threshold during any time in a given calendar year of the permit cycle, that Decision-maker must
then submit an NOI consistent with the due dates described in Part 1.2.3 of the PGP.

When calculating the size of the treatment area for comparing to an annual treatment area
threshold, EPA uses the term "at water's edge adjacent to waters of the United States" to identify
those areas where pesticides are applied to control pests that are present near water where a
portion of the pesticides will unavoidably be deposited to the water to target the pests. EPA's use
of the word "adjacent" in identifying these areas is merely used to identify areas near waters of
the United States and is not intended to mean "adjacent" as defined in regulation for use when
defining the term "waters of the United States."

To avoid duplication of submission, EPA is requiring that the Decision-maker responsible
for such applications be the Operator required to submit the NOI. So, where a Decision-maker
hires an Applicator to perform the pest control activities, the NOI is to be submitted by the
Decision-maker.

EPA's rationale for the annual treatment area threshold and Decision-makers required to
submit NOIs for each use pattern is as follows:

Mosquito Control and Other Flying Insect Pest Control

For Mosquitoes and Other Flying Insect Pests, the annual treatment area threshold has been
set at 6,400 acres of pesticide application to waters of the United States. Calculation of annual
treatment area for mosquito control should only count areas treated with adulticide. Larviciding
is not to be used in the calculations. EPA understands that the vast majority of mosquito control
and abatement districts in the United States manage areas significantly larger than this threshold

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and may reasonably expect to exceed it during any given year. For instance, information from
the state of Florida on 49 independent mosquito control districts shows that 48 of the 49 districts
annually apply to more than 6,400 acres, which indicates that applications exceeding this area are
quite typical. Similarly, data provided in EPA's 2011 Economic Achievability Analysis of the
Pesticide General Permit (PGP) for Point Source Discharges from the Application of Pesticides
and included in the administrative record for this permit, show similar findings as in Florida.
Furthermore, the effective control of other aquatic breeding, flying insects, such as the blackfly,
necessitates applications that approach or exceed this threshold. Therefore, the threshold
appropriately captures most Decision-makers engaging in this use pattern.15 The Agency has
determined this appropriately captures those two classes of entities that either (1) are established
with a specific purpose of pest control or that (2) treat large enough areas to warrant notice to the
Agency.

Weed and Algae Control

For Weeds and Algae, the annual treatment area threshold has been set at 80 acres or 20
linear miles of pesticide application to canals and other waters of the United States. This
threshold has been set to capture Decision-makers treating relatively large portions of surface
waters and watersheds, such as water management districts, wildlife and game departments, and
some homeowner and lake associations. For example, Florida's South Florida Water
Management District usually applies pesticides to 60 acres at a time hundreds of times per year
for various invasive plants on Florida's Lake Okeechobee. After reviewing the operations of
major irrigation and flood control systems as part of the initial PGP development, EPA expects
that generally, relatively large entities such as South Florida Water Management District,
California Department of Water Resources, or organizations with comparable resources are the
types of entities that manage 20 or more miles of engineered irrigation systems, and that this is a
reasonable limit to trigger the NOI requirement. The same rationale is applied to managers of
ditch and canal banks. Therefore, the threshold appropriately captures the relatively large
applications but excludes a significant number of small applications. Similar to mosquito control,
weed control districts, or similar pest control districts created specifically for the control of pests
that treat areas below the threshold, should be required to submit NOIs. As such, the permit
requires all weed control districts or similar pest control districts as well as any other Decision-
makers treating over the annual treatment area threshold to submit an NOI. The Agency has
determined that this appropriately captures those two classes of entities that either (1) are
established with a specific purpose of pest control or that (2) treat large enough areas to warrant
notice to the Agency.

Animal Pest Control

For Animal Pest Control, the annual treatment area threshold has been set at 80 acres or 20
linear miles of pesticide application to canals and other waters of the United States. Invasive and
nuisance aquatic animals are most commonly treated by public agencies such as departments of

15 As discussed below, EPA also finds that even those mosquito control districts that treat areas below the threshold
should be required to submit NOIs, as these entities were created specifically for the control of pests and should
provide notice to the Agency of their activities.

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fish and game, or utilities such as water management districts. The high mobility and prolific
breeding abilities that necessitate control of aquatic animals usually mean that pesticide
applications most often occur in the entirety or large portions of the water bodies they inhabit.
For example, fishery management applications using rotenone often occur in the entire lake, and
thus any similar application to a lake of more than 80 acres in area will trigger the annual
treatment area threshold. EPA expects that for this reason, only spot applications to eradicate
small emergent populations of sessile animals or applications to very small water bodies might
be excluded from an NOI requirement. Therefore, the threshold appropriately captures the
relatively large Decision-makers engaging in this use pattern.

Forest Canopy Pest Control

For Forest Canopy Pest Control, the annual treatment area threshold has been set at 6,400
acres of pesticide application to waters of the United States. Forest canopy pest suppression
programs are designed to blanket large tracts of terrain, throughout which Operators may not be
able to see waters of the United States beneath the canopy. EPA has set the annual treatment area
threshold for this use pattern with the understanding that this will exclude only the smallest
applications from the NOI requirement. These smaller applications generally occur on private
lands. Therefore, the threshold appropriately captures most Decision-makers engaging in this use
pattern, particularly public agencies managing large tracts of land.

NOIs for Certain Entities Regardless of the Annual Treatment Area Threshold

In addition to NOIs from Decision-makers treating the largest areas, EPA is also requiring
NOIs from certain other types of entities with land resource stewardship responsibilities that
involve the routine control of pests. For these entities, the draft 2026 PGP requires NOIs
regardless of the size of the area treated. In general, EPA expects that in many instances these
entities will exceed one or more of the annual treatment area thresholds. Nonetheless, the
Agency finds that regardless of the size of the treatment area, any Agency for which pest
management for land resource stewardship is an integral part of the organization's operations
should also be required to submit NOIs. Such entities may include federal government agencies
such as the U.S. Forest Service (U.S. Department of Agriculture) and the Bureau of Land
Management (Department of the Interior), state government agencies such as natural resources
departments, or pest control districts. EPA's rationale for imposing the NOI requirement is
premised on these entities (public, quasi-public, and private) having as an integral responsibility
controlling pests. The specific entities required to submit NOIs regardless of whether an annual
treatment area threshold is exceeded are as follows:

Any Agency for which pest management for land resource stewardship is an integral part of the
organization's operations - Any agency that has pest control as an integral part of the
organization's operations or responsibilities is required to submit an NOI. Information in the
record indicates that many pest control activities performed by these entities will meet or exceed
the threshold requirement to submit an NOI. Even when these activities do not exceed the
thresholds, however, they are subject to the NOI requirement if the pesticide application is an
integral part of their operations and responsibilities. EPA also recognizes, however, that some of
these agencies may perform ad-hoc pest control on a small-scale that is not an integral part of the
organization's operations but rather incidental, for example, to its occupancy of a building.

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

Mosquito control districts (or similar pest control districts, such as vector control districts) - In
many parts of the country, state and territorial governments have established special districts for
the purpose of mosquito control. Generally, these districts treat large areas that would exceed
EPA's annual treatment area thresholds; however, EPA is requiring any such district, regardless
of the area treated, to submit an NOI.

Irrigation control districts (or other similar public or private entities supplying irrigation
waters) - In many parts of the country, special districts have been established for the purpose of
maintaining irrigation canals and ditches. Generally, these districts treat large areas that exceed
EPA's annual treatment area thresholds; however, EPA is requiring any such district, regardless
of the area treated, to submit an NOI.

Weed control districts (or other similar special purpose districts created with a responsibility of
pest control) - EPA is aware of some weed control districts created across the country with the
specific responsibility to control pests. The Agency has determined that these types of entities,
who perform pest management and control, as the primary function of their organization, should
provide notice to the Agency of such activities regardless of the size of the area treated.

NOIs for Discharges of Pollutants to Tier 3 Waters

Any Decision-maker requesting to discharge pollutants to Tier 3 waters may seek coverage
under the PGP provided that the discharge of pollutants is short-term or temporarily lowers water
quality due to pesticide applications that are necessary to protect the water quality, environment,
or public health. Any Decision-maker wanting coverage under the draft 2026 PGP for such a
discharge will be required to identify the Tier 3 water by name with authorization to discharge
pollutants to Tier 3 waters limited to only such named waters.

NOIs for Discharges of Pollutants to Waters of the United States Containing NMFS Listed
Resources of Concern, as Defined in Appendix A of the PGP

Any Decision-maker with any discharges of pollutants to waters of the United States
containing NMFS Listed Resources of Concern, as defined in Appendix A of the PGP, may seek
coverage under the permit by submitting a complete and accurate NOI form that includes
certifying eligibility under one of the five criteria (B-F) in Part 1.1.2.4 of the PGP. NOTE: EPA
is proposing the same ESA procedures for FWS under the draft 2026 PGP as described above for
NMFS. A Decision-maker with any discharges of pollutants to waters of the United States
containing FWS Listed Resources of Concern may also seek coverage by submitting a complete
and accurate NOI.

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for

publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.

Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in

the Federal Register.

APPENDIX H. Recommended Pesticide Use Pattern Reference

Recommended Mosquito Control References

EPA recommends the following sources for additional information on Pest Management

Measures for mosquito control:

Anderson, RR and LC Harrington et al. 2010. Mosquito Biology for the Homeowner. Cornell
Cooperative Extension - Medical Entomology Extension. Available at:
http://blogs.cornell.edu/harrington/files/2014/01/Mosquito-Biologv-for-the-
Homeowner final-2014-18iwdiw.pdf

American Mosquito Control Association. 2009. Mosquito Information. Available at:
https://www.mosquito.org/page/mosquitoinfo

American Mosquito Control Association. 2009. Mosquito Info: Control.
https://www.mosquito.org/page/control

California Department of Public Health. 2008. Best Management Practices for Mosquito Control
on California State Properties. Available at:

http://westnile.ca.gov/downloads.php7download id=996&filename=CDPH BMP
MosquitoControl6-0%.vdf

Commonwealth of Massachusetts Department of Food and Agriculture State Reclamation and
Mosquito Control Board. 1998. Generic Environmental Impact Report (GEIR). For the
Massachusetts Mosquito Control. Available at: https://www.mass.gov/service-
details/mosquito-control-and-spraving

Florida Coordinating Council on Mosquito Control. 2018. Florida Mosquito Control - The State
of Mission as defined by mosquito controllers, regulators, and environmental managers.
Available online at: https://fmel.ifas.ufl.edu/media/fmelifasufledu/7-15-2018-white-
paper.pdf

New York City Department of Health and Human Hygiene. 2016. Comprehensive Mosquito
Surveillance and Control Plan. Available at:

https://wwwl.nvc.gov/assets/doh/downloads/pdf/wnv/2016/wnvplan2016.pdf

Grodner, MG, J Criswell, C Sutherland, P Spradley, DL Renchie, ME Merchant, M Johnsen, and
S Sawlis. 2007. The Best Way to Control Mosquitoes - Integrated Mosquito Management
Explained. Available at: https://www.uaex.uada.edu/publications/pdf/agll66.pdf

Kwasny, DC, M Wolder, and CR Isola. 2004. Technical Guide to Best Management Practices for
Mosquito Control in Managed Wetlands. Central Valley Joint Venture. Available at:
http://www.centralvalleviointventure.org/assets/pdf/CVJV-Mosquito-BMP.pdf

Rose, RI. 2001. Pesticides and Public Health: Integrated Methods of Mosquito Management.
Emerging Infectious Diseases 7:1. State of Massachusetts. 2008. Massachusetts Best
Management Practices and Guidance for Freshwater Mosquito Control. Available at:
https://www.mass.gov/doc/freshwater-bmp-to-mepa/download

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State of New Hampshire. 2008. Policy for Mosquito Control on State Lands. Available at: EPA
docket number EPA-HQ-OW-2020-0005

State of New Mexico. 2008. Philosophy of Mosquito Control.
http://nmhealth.org/publication/view/guide/992/

Washington State Department of Ecology/Water Quality Program. 2004. Best Management
Practices for Mosquito Control. Available at:
https://fortress.wa.gov/ecv/publications/publications/0310023.pdf

Recommended Black Fly Control References

EPA recommends the following sources for additional information on Pest Management
Measures for black fly control:

Commonwealth of Pennsylvania. 2009. Black Fly Suppression Program. Available at:
https://www.dep.pa.gov/Business/ProgramIntegration/Vector-
Management/BlackFly/Pages/default, aspx

Government of Alberta - Agriculture and Rural Development. 1993. Black Fly Control.

Available at: https://open.alberta.ca/dataset/2397254#summary

Greater Los Angeles Vector Control District. 2016. Black Flies - Vector Services and
Information. Available at: https://www.glamosquito.org/black-flies

Metropolitan Mosquito Control District. 2009. Biting Gnat/Black Fly Control. Available at:
http://www.mmcd.org/biting-gnat-control/

North Carolina Cooperative Extension. 2005. Insect Notes - Black Flies and Their Control.
Available at: http://www.ces.ncsu.edu/depts/ent/notes/Urban/blackfly.htm

North Elba - Black Fly Control Dept. 2009. About the black fly control program. Available at:
http://www.northelba.org/?page=services/black-fly-control-dept

Ohio State University Extension. 1997. Factsheet - Black Flies. HYG-2167-97.

The Merck Veterinary Manual. 2016. Black Flies. Available at:
https://www.merckvetmanual.com/integumentarv-svstem/flies/black-flies

Undeen, AH and DP Malloy. 1996. Use of stream width for determining the dosage rates of
Bacillus Thuringiensis Var. israelensis for larval black fly (Diptera: Simuliidae) control. Journal
of the American Mosquito Control Association. 12(2): 312-315.

University of Florida. 2007. Featured Creatures - Black Flies. EENY-30. Available at
http://entomologv.ifas.ufl.edu/creatures/livestock/bflv.htm

University of New Hampshire Cooperative Extension. 2001. Black Flies. Available at:
http://www.ultimate.com/washington/wla/blackfly/

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

Recommended Weed and Algae Control References

EPA recommends the following sources for additional information on Pest Management
Measures for weed and algae control:

Aquatic Nuisance Species Taskforce. Available at https://fws.gov/program/aquatic-nuisance-
species-task-force

Getsinger, K., Moore, M. D., Layne, C. P., Petty, D. G., L, S., Sprecher, Dibble, E. D., Karcas,
E., Maceina, M., Mudrak, V., Lembi, C., Madsen, J. D., Stewart, R. M., Anderson, L., Haller,
W., Confrancesco, A., Newman, R., & Nibling, F. (2005). Aquatic Plant Management Best
Management Practices in Support of Fish and Wildlife Habitat. Aquatic Ecosystem Restoration
Foundation. Lansing, MI. https://www3.nd.edu/~aseriann/Aquatic_Plants_BMP.pdf

Gettys, L. A., Haller, W. T., & Bellaud, M. (2009). Biology and control of aquatic plants.
Marietta GA: Aquatic Ecosystem Restoration Foundation. Available at
http://www.fs.usda.gov/Internet/FSE DOCUMENTS/stelprdb53735Q9.pdf

Recommended Animal Pest Control References

EPA recommends the following sources for additional information on Pest Management
Measures for animal control:

Aquatic Nuisance Species Taskforce. Online: http://www.anstaskforce.gov/.

Getsinger, K., Moore, M. D., Layne, C. P., Petty, D. G., L, S., Sprecher, Dibble, E. D., Karcas,
E., Maceina, M., Mudrak, V., Lembi, C., Madsen, J. D., Stewart, R. M., Anderson, L., Haller,
W., Confrancesco, A., Newman, R., & Nibling, F. (2005). Aquatic Plant Management Best
Management Practices in Support of Fish and Wildlife Habitat. Aquatic Ecosystem Restoration
Foundation. Lansing, MI.

Aquatic Nuisance Pest Task Force (ANP). (2011). Northern Snakehead. Fish and Wildlife
Services. Retrieved May 18, 2021 from: https://www.fws.gov/program/aquatic-nuisance-species-
task-force/control

Gaikowski, M. (2018). Asian Carp Control. U.S. Department of the Interior. Retrieved May 18,
2021 from: https://www.doi.gov/ocl/asian-carp-control

National Park Service (NPS). (2019). Asian Carp Overview. National Park Service. Retrieved
May 18, 2021 from: https://www.nps.gov/miss/learn/nature/ascarpover.htm

Recommended Forest Canopy Pest Control Reference

EPA recommends the following sources for additional information on Pest Management
Measures for forest canopy pest control:

Emily Grafton and Ralph Webb. Homeowner's guide to gypsy moth management. West Virginia
University Extension Service. http://www.ni.gov/agriculture/divisions/pi/pdf/GMguide.pdf

USD A. (rev. 2019). Gypsy Moth Program Manual.

http://www.aphis.usda.gov/import export/plants/manuals/domestic/downloads/gypsv moth.pdf

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

USDA. 2016. Asian Gypsy Moth Factsheet.

https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5187452.pdf

Reardon, Podgwaite, and Zerillo. GYPCHEK- Environmentally Safe Viral Insecticide for Gypsy
Moth. FHTET-2012-01. 2nd ed. March 2016. U.S. Department of Agriculture, Forest Service.
https://www.fs.usda.gov/research/treesearch/45390

Kucera, Daniel and P. Orr. Spruce Budworm in the Eastern United States. U.S. Department of
Agriculture, Forest Service. Forest Insect and Disease Leaflet 160.
https://www.fs.usda.gov/Internet/FSE DOCUMENTS/fsbdev2 042853.pdf

Michael, Jerry. 2004. Best Management Practices for Silvicultural Chemicals and the Science
Behind Them. Water, Air, and Pollution: Focus. 4(1), 95-11.
https://www.fs.usda.gov/research/treesearch/6291

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APPENDIX I. Factors to Meet Applicable Water Quality Standards

In general, EPA expects that compliance with the other conditions in this permit (e.g., the
technology-based limitations, corrective actions, etc.) will result in discharges of pollutants that
are controlled as necessary to meet applicable water quality standards based on the cumulative
effect of the following factors:

(1) Under FIFRA, EPA evaluates risks associated with pesticides and considers mitigation
measures to address risks that exceed levels of concern.

Background

EPA regulates the use of pesticides under the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA). In general, FIFRA authorizes EPA to register each pesticide product
intended for distribution or sale in the United States. To register a pesticide, the Agency must
determine that its use in accordance with the label will not cause "unreasonable adverse effects
on the environment." (see, e.g., FIFRA sec. 3(c)(5)). FIFRA defines that term to mean, in part,
"any unreasonable risk to man or the environment, taking into account the economic, social, and
environmental costs and benefits of the use of any pesticide" (FIFRA sec. 2(bb)). The
"unreasonable adverse effects" standard requires EPA, in effect, to balance the human health and
ecological risks of using a pesticide against its economic, social, human health, and ecological
benefits. Pesticides are registered for sale and distribution only if EPA determines that the
benefits outweigh the risks. In making decisions on whether to register a pesticide, EPA
considers the use directions on proposed product labeling and evaluates data on product
chemistry, human health, ecological effects, and environmental fate to assess the potential risks
associated with the use(s) proposed by the applicants for registration and expressed on the
labeling. Among other things, the Agency evaluates the risks to human health and the
environment (including water quality) posed by the use of the pesticide.

As stated above, EPA reviews and approves pesticide product labeling. EPA implements
risk mitigation measures identified through the risk assessment process by placing use
restrictions and warnings on labeling to ensure the use of the pesticide (under actual use
circumstances and commonly accepted practice) will not cause any "unreasonable adverse
effects on the environment." It is a violation under FIFRA sec. 12(a)(2)(G) (FIFRA's "misuse"
provision) to use a registered pesticide inconsistent with its labeling.

After a pesticide has been registered, changes in science, public policy, and pesticide use
practices will occur over time. FIFRA, as amended by the Food Quality Protection Act of 1996,
mandates a registration review program, under which the Agency periodically reevaluates
pesticides to ensure that as the ability to assess risk evolves and as policies and practices change,
all registered pesticides continue to meet the statutory standard of no unreasonable adverse
effects to human health or the environment. The Agency is implementing the registration review
program pursuant to Section 3(g) of FIFRA and will review each registered pesticide every
15 years to determine whether it continues to meet the FIFRA standard for registration.
Information on this program is provided at: http://www.epa.gov/pesticide-reevaluation.

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Ecological Risk Assessment

The following is a discussion about the FIFRA risk assessment process with a focus on
Ecological (specifically aquatic) Assessments. Entities seeking pesticide registrations bear the
burden of demonstrating their products meet the statutory standard under FIFRA. As set forth in
40 CFR Part 158, applicants for pesticide registrations must provide EPA with a suite of product
chemistry, residue chemistry, toxicity, environmental fate, and ecotoxicity studies, to support an
application for registration. To support outdoor uses, studies are required that provide
information related to the environmental fate and transport of the chemical and that measure the
acute and chronic toxicity to terrestrial and aquatic organisms. These studies, along with open
literature that meet data quality guidelines, are the basis for the ecological risk assessments. The
ecological risk assessment combines the results of an environmental exposure assessment and an
ecological effect assessment for a pesticides active ingredients to produce a quantitative measure
of potential risk.16 A risk characterization is also presented to put the quantitative assessment of
risk in the context of other lines of evidence, such as available monitoring data and incident
reports, and to discuss uncertainties in the risk assessment. The quantitative and qualitative
determination of potential ecological risk is independent of economic or other benefit
considerations.

Aquatic Exposure Characterization

EPA estimates pesticide concentrations in aquatic environments to determine if exposure to
a pesticide active ingredient is at a level that could cause unreasonable adverse effects to aquatic
organisms. EPA estimates pesticide concentrations in water using peer-reviewed simulation
modeling because there are not sufficient monitoring data to estimate exposure to aquatic
organisms under all potential use conditions. When available, monitoring data are used to help
characterize aquatic exposure.

EPA also estimates potential exposure from uses involving direct application to water. The
model used for pesticides applied directly to water uses environmental fate data to simulate
partitioning of the pesticide between the water column and bottom sediment in a standard rice
paddy. This modeling is conservative because it does not simulate degradation of the applied
pesticide, as would be necessary to estimate the amount of residue remaining after the pesticide
product had performed its intended function. Depending on the rate of degradation, the initial
concentration as estimated by the model could be much higher than the residual concentration
remaining after pesticide application has been completed. Additionally, this modeling scenario is
conservative because the resulting exposure estimate is the concentration in the paddy water
itself, not considering dilution which would occur when paddy water is diluted by precipitation
or when it is released into a receiving water body. See the U.S. EPA. 2004. Overview of the
Ecological Risk Assessment Process in the Office of Pesticide Programs. Office of Prevention,
Pesticides, and Toxic Substances. Office of Pesticide Programs. Washington, D.C. January 23,
2004. https://www.epa.gov/endangered-species/ecological-risk-assessment-process-under-
endangered-species-act

16 As part of the risk assessment, EPA also examines available information to determine the need to expand beyond
the focus on the active ingredient to consider pesticide formulation, inert ingredients, or degradates.

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As discussed above, when available, EPA uses ambient water monitoring data as a line of
evidence to characterize aquatic exposure in ecological and human health risk assessments. The
United States Geological Survey (USGS) maintains several sources of pesticide monitoring data.
These sources include the National Water Quality Assessment program (NAWQA), the Toxic
Substances Hydrology Program, and the National Stream Quality Accounting Network
(NASQAN). EPA sources of water monitoring data include STORET, a storage and retrieval
database of national water quality information, the Safe Drinking Water Information System
(SDWIS), Office of Water compliance monitoring data, and the USGS/EPA Reservoir
Monitoring Program. In addition to the federal data sources, monitoring data are sometimes
available from States, pesticide registrants, and the open literature.

These monitoring data are evaluated on a case-by-case basis to help characterize the
likelihood, extent, and nature of pesticide concentration in water under current use practices and
actual field conditions. EPA considers the locations and frequency of sampling, the analytical
methods, the detection limits, and the purpose of the monitoring studies from which the data are
derived when determining how such data will be incorporated into the FIFRA risk assessment
and the usefulness of the monitoring data for an aquatic exposure assessment. For example, a
monitoring study targeted to measure concentrations of a pesticide in a watershed with high
agricultural use of that pesticide will not provide much insight on the potential exposure from its
use as a mosquito adulticide. Similarly, a general survey of ambient water quality might not
necessarily target specific pesticide use areas or the time of year when pesticide concentrations
may be at their peak, and for this reason may not provide a reliable estimate of acute exposure.
However, if monitoring data from such a study shows higher confirmed detections than
estimated by modeling, the higher monitoring values typically would be used in the risk
assessment.

Aquatic Effects

To determine if a pesticide is sufficiently toxic at its estimated exposure concentrations to
cause unreasonable adverse effects in the environment, EPA reviews available ecotoxicity data.
These data may come from a number of sources, including direct guideline study submissions
required in support of registration, and open literature data retrieved through ECOTOX17. The
typical assessment endpoints for pesticide ecological risk assessments are reduced survival from
direct acute exposures and survival, growth, and reproductive impairment from direct chronic
exposures. As noted in the OPP Overview18 document, which describes the process OPP uses to
conduct ecological risk assessment under FIFRA, OPP evaluates other data on sublethal effects
in addition to direct effects on survival, growth, and reproduction.

17 U.S. EPA. 2007. Ecotoxicity Database (ECOTOX) Mid-Continent Ecology Division, National Health and
Environmental Effects Research Laboratory. U.S. Environmental Protection Agency, Office of Research and
Development, https://www.epa.gov/chemical-research/ecotoxicologv-database.

18 U.S. EPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide Programs. Office
of Prevention, Pesticides, and Toxic Substances. Office of Pesticide Programs. Washington, D.C. January 23, 2004.
Support Document 1: Study Classification used by EFED in Data Evaluation Records (DERs)
https://www.epa.gov/sites/production/files/2014-ll/documents/ecorisk-overview.pdf

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In general, the current FIFRA data regulations require studies that include but are not
limited to a suite of aquatic toxicity studies for effects characterization. These test requirements
are defined for each chemical class by use category (40 CFR Part 158 Subpart D; Wildlife and
Aquatic Organism data requirements;

http://edocket.access.gpo.gov/cfr 2007/iulqtr/40cfrl58.490.htm) and are performed on a limited
number of laboratory test organisms in the following broad taxonomic groupings:

- Freshwater fish;

- Freshwater invertebrates;

- Estuarine/marine fish;

- Estuarine/marine invertebrates; and

- Algae and aquatic plants.

Within each of these very broad taxonomic groups, the most sensitive acute and chronic
toxicity value is selected from all available test data, including open literature and registrant
submissions. If additional toxicity data for more species of organisms in a particular group are
available, the most sensitive toxicity values from all sources for other species/studies that meet
data quality standards are used in the risk assessment.19 Aquatic toxicity data are required for
each active ingredient, but aquatic toxicity data are also required on the typical end use product
for any pesticide that will be introduced directly to aquatic environments (40 CFR Part 158.630).

Risk Characterization

Risk characterization is the integration of effects and exposure characterization to determine the
ecological risk from the use of the pesticide and the likelihood of effects on non-target species
based on the pesticide-use scenarios. In FIFRA screening-level assessments, OPP relies on the
deterministic risk quotient (RQ) method to compare estimated exposure to toxicity endpoints.
Estimated environmental concentrations (EECs) derived in the exposure characterization are
divided by acute and chronic toxicity endpoints identified in the effects characterization. Risk
quotients are then compared to the Agency's Levels of Concern (LOCs). These LOCs are the
Agency's interpretative policy and are used to analyze the potential risk to non-target organisms
and the need to consider regulatory action. These criteria are used to indicate when a pesticide
use as directed on the label has the potential to cause adverse effects on non-target organisms. If
a risk of concern is identified, risk mitigation measures are considered.

Risk Mitigation

EPA acknowledges that there are uncertainties in its pesticide risk assessments (see full
discussion below), nonetheless the Agency reduces the risks of concern by imposing additional
restrictions on the use of a pesticide to reduce pesticide concentrations in the aquatic
environment. Mitigation measures may include limits on the amount and frequency that a
pesticide may be applied, or the application methods may be restricted to limit off-site transport.
Mitigation may also limit the geographical areas to which a pesticide can be applied or may
include mandatory buffer distances from sensitive habitats. Mitigation measures are

19 Ibid U.S. EPA 2004

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implemented through product labeling instructions, with which pesticide users are required to
comply.

In some cases, EPA restricts the use of a pesticide so that levels of pesticide predicted by
the model to reach water are below the relevant aquatic benchmarks (see Aquatic Benchmarks
discussion below). In other cases, using the FIFRA risk-benefit balancing standard, EPA may
permit the use of a pesticide even though the estimated water concentration might exceed a
relevant benchmark. In such cases, the decision incorporates consideration of the benefits of the
pesticide use and other lines of evidence, such as any available National Recommended Water
Quality Criterion for ambient water quality, concerning the conservativeness of the modeling
assessment and available monitoring data.

Uncertainties with Risk Assessment and Mitigation

For the majority of pesticides, the Agency relies on simulation modeling to predict
potential aquatic exposure following pesticide applications. There are uncertainties embedded in
the FIFRA exposure assessment, for example, the extent to which the simulated scenario
represents actual use conditions in terms of hydrologic vulnerability and the amount and
frequency with which pesticides are applied. In order to account for the inherent uncertainty, the
Agency uses a combination of parameters and assumptions in the models that results in estimated
potential exposure concentrations that are high-end and are not likely to underestimate actual
aquatic exposure. This allows the Agency to identify pesticides that are not likely to pose a risk
to aquatic life.

In the effects characterization under FIFRA, the lowest acute and chronic toxicity values
from the most sensitive species tested in acceptable studies are used as the relevant endpoint for
evaluating risk to various taxa. Implicit in the use of the lowest toxicity values for the most
sensitive species is the presumption that these toxicity values afford protection not only for the
individual surrogate species but for other untested taxa as well.

In the FIFRA risk characterization, data gaps are also considered as a source of uncertainty
in the risk assessment conclusions, and each risk assessment discusses the potential for additional
data to affect the risk assessment conclusions.

An additional source of uncertainty in assessing risk to aquatic life is the impacts of
multiple stressors on aquatic organisms. A United States Geological Survey (USGS) 10-year
study (Gilliom et al., 2006) shows that the most common form of pesticide exposure for aquatic
organisms is simultaneous exposure to multiple pesticides. More than 50 percent of all stream
samples contained five or more pesticides, although the majority of mixtures are comprised
mainly of agricultural herbicides and degradates of these herbicides, or urban/residential use
insecticides in urban streams. Pesticides that will be applied under the PGP may also co-occur
with other manmade contaminants and/or other pesticides from other uses. For instance, the
USGS has also performed monitoring studies which revealed the widespread presence of some
pharmaceuticals and personal care products in drinking water. However, although pesticides may
be detected with other chemicals or in discharges of pollutants covered by other NPDES permits,
the majority of research and data on the effects of pesticides has focused on individual pesticides

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rather than on additive and synergistic toxic effects of exposure to multiple pesticides and/or
non-pesticide toxicants.

Possible interactions among pesticides or between pesticides and other contaminants may
occur including: independent, additive, antagonistic, or synergistic. The variety of chemical
interactions presented in the available literature20 suggests that the interaction can be a function
of many factors including but not necessarily limited to: (1) the exposed species, (2) the co-
contaminants in the mixture, (3) the ratio of concentrations in the mixture, (4) differences in the
pattern and duration of exposure among contaminants, and (5) the differential effects of other
physical/chemical characteristics of the receiving waters (e.g., organic matter present in sediment
and suspended water). Quantitatively predicting the combined effects of all these variables on
mixture toxicity to any given taxon with confidence is beyond the capabilities of the available
data. In order to assess the impacts of environmental mixtures on aquatic life, states have
included ambient toxicity testing (also called Whole Effluent Toxicity or WET testing) in their
monitoring programs. WET testing allows states to identify potential impacts to aquatic life and
identify the toxicant(s) and through the toxicity reduction evaluation, reduce the source(s) of the
toxicant(s). The level of toxic effect to the most sensitive tested species is therefore assumed to
be protective of other species that may be present in any given water body and is assumed to
represent the most toxic component of a mixture. Note that a discussion of EPA's consideration
of WET testing as a condition of the permit is discussed in Part III.4 of this fact sheet.

Aquatic Benchmarks

EPA's Office of Pesticide Programs (OPP) derives aquatic benchmarks by multiplying the
most sensitive toxicity values (i.e., the lowest acceptable toxicity value for the most sensitive
species within a taxonomic group) by their respective (level of concern) LOC. These taxon-
specific benchmarks, based on toxicity data used by OPP in assessments for FIFRA pesticide
registration decision-making, are considered estimates of the concentrations below which
pesticides are not expected to have the potential for adverse effects for the particular taxon for
which those data serve as surrogates. It is reasonable to assume that above these levels, there
may be potential for the pesticide to cause adverse effects to the given taxon.

EPA's Office of Water (OW) and OPP agreed that these values can be used by States and
others to evaluate potential risks of pesticides in the aquatic environment, if a National
Recommended Water Quality Criterion for ambient water quality is not available.21 A number of
states have used these benchmark values as indicators of whether pesticide residues detected in
surface water warrant additional action such as refined monitoring efforts. While benchmarks
can be useful as a screening tool, they do not provide the information necessary to link detected
concentrations with their sources.

20 National Research Council 2013. Assessing Risks to Endangered and Threatened Species from Pesticides.
Washington, DC: The National Academies Press.

21 Correspondence to SFIREG, November 3, 2006 from Office of Water director.

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In response to recommendations and input from stakeholders, EPA developed a webpage
of non-regulatory "OPP Aquatic Benchmarks."22

As described above, EPA's FIFRA risk assessment process includes conservative
assumptions that, taken as a whole, mitigate unreasonable ecological risk and protect water
quality.

(2) Examination of national-scale ambient monitoring data to assess whether pesticide
residues are currently present in waters at levels that would exceed water quality
standards.

Environmental Science and Technology: Pesticides in U.S. Streams and Rivers: Occurrence
and Trends during 1992—2011

In addition to the protective nature of the pesticide risk assessment, EPA reviewed readily
available surface-water monitoring data from the USGS National Water-Quality Assessment
(NAWQA) Project. In 2006, the USGS NAWQA23 released a 10-year (1992-2001) study of 51
major river basins and aquifer systems that account for more than 70 percent of total United
States water use, and more than 50 percent of the United States drinking water supply. During
the 2011 PGP development, EPA reviewed the data and found a total of 20 pesticides or
degradates exceeded an EPA benchmark in one or more agricultural stream and/or urban stream
(see the 2011 PGP, Appendix A of the fact sheet for a complete list of pesticides/degradates that
had exceedances). Since 2001, EPA noted that regulatory actions taken under FIFRA with
respect to all 20 pesticides found to be in excess of a benchmark, and many of their uses have
been canceled (several detections were of pesticides no longer in use prior to the start of the
study). See the 2011 PGP, Appendix C of the fact sheet for a summary of pesticide-specific
exceedance data and risk mitigation actions.

In 2014, the USGS NAWQA24 released a study of pesticide monitoring in streams and
rivers across the U.S. for the decade of 2002-2011 that compares monitoring data to previously
reported findings from the decade of 1992-2001. During the 2016 PGP development, EPA
reviewed this USGS second decadal report and noted the findings in the accompanied fact sheet.
As USGS had not released another similar report during the 2021 PGP development, for the
2021 PGP's fact sheet, EPA noted the findings from the last review and updated EPA's
regulatory actions under FIFIRA. This USGS report indicated that with regard to chronic aquatic
life benchmarks, during 1992 - 2001, 16 pesticides exceeded a chronic aquatic life benchmark,
while during 2002 - 2011, twenty-one pesticides exceeded a chronic aquatic life benchmark. See
Appendix A of the fact sheet for the 2016 PGP and 2021 PGP. Forty-seven pesticides were

22 OPP Aquatic Benchmark Table https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/aauatic-life-
benchmarks-pesticide-registration

23 Gilliom and others 2006. The Quality of Our Nation's Waters-Pesticides in the Nation's Streams and Ground
Water, 1992-2001: U.S. Geological Survey Circular 1291, 172p.

24 Stone and others 2014. An Overview Comparing Results From Two Decades of Monitoring for Pesticides in the
Nation's Streams and Rivers, 1992-2001 and 2002-2011. U.S. Geological Survey Scientific Investigations Report
2014-5154, 23 p.

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assessed in both decades. For 10 of these25 with benchmark exceedances in both decades,
exceedance frequencies were mostly lower during 2002 - 2011.26 27This research found that the
proportion of assessed streams with one or more pesticides that exceeded a chronic aquatic life
benchmark were very similar between the two decades for agricultural (69% for 1992 - 2001
compared to 61% for 2002 - 2011) and mixed use streams (45% compared to 46%). For urban
streams the percentage increased from 53% during 1992 - 2001 to 90% during 2002 - 2011
predominantly due to the use of fipronil and dichlorvos in the latter decade (these two pesticides
are among those not assessed for 1992 - 2001). Additional detail on the nature of EPA's
regulatory actions under FIFRA appears in Appendices B and C of the fact sheet for the 2016
PGP and 2021 PGP.

In 2021, the USGS NAWQA published, Surface Water Pesticide Detection Frequency and
Benchmark Exceedance Data for the Conterminous United States, 2013-2017. This publication
consists of pesticide detections and benchmark exceedances in surface waters. These are time
series data representing water years 2013 - 2017 for river sites associated with the U.S.

Geological Survey National Water Quality Pesticide Monitoring Program. During the 2026 PGP
development, EPA reviewed this USGS report and noted the findings in this fact sheet. This
USGS report indicated that with regard to chronic aquatic life benchmarks, during 2013-2017,
seventeen pesticides exceeded a chronic aquatic life benchmark. See Appendix A of the fact
sheet. In Appendix B, EPA noted the regulatory status under FIFRA and applicable mitigation
measures for 17 pesticide active ingredients with at least one aquatic life benchmark exceedance.

State Water Quality Monitoring under CWA

States must place waterbodies not meeting water quality standards on a list (303(d) list)
which identifies the pollutant or pollutants causing or expected to cause the impairment. The
Office of Water's Impaired Waters and Total Maximum Daily Loads website28 (accessed
February 2020) indicates 303(d) impairments in several states for 18 currently registered specific
pesticides and 4 general classes of pesticides (e.g., pyrethroids; Table 1). With the adoption of a
303 list, states are required to develop a Total Maximum Daily Load (TMDL). States also must
include a priority ranking for developing those TMDLs. A critical component in the TMDL
process is to identify the sources of each parameter for which the waterbody is listed. Then, the
State must develop waste load allocation(s) for point source(s) and load allocation(s) for
nonpoint source(s).

25 Metolachlor, Atrazine, Diazinon, Malathion, Chlorpyrifos, Carbaryl, Azinphos methyl, cis-Permethrin,
Disulfoton, Parathion.

26 Stone and others 2014. Pesticides in U.S. Streams and Rivers: Occurrence and Trends during 1992-2011.
Environmental Science and Technology, 2014, 48, 11025-11030.

27 EPA notes that none of these 10 pesticides are among the top 10 solid or top 10 liquid or top 10 briquettes
pesticide active ingredients applied under the 2016 PGP as reported in the 2018 annual report data. Seven of these
top ten 10 pesticides are biological pesticides.

28 https ://mvwaterwav. epa. gov/

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Table 1. Currently registered pesticide active ingredients listed as causes of 303(d) impairment
(data accessed February 2020)

NOTE TO REVIEWER: This table will be updated for the final permit.

Cause of Impairment

States

Aldicarb

Atrazine

IL, KS, LA, MO, NE, OH

Bifenthrin

Carbaryl

Chlorpyrifos

CA, ID, MN, OK, OR, WA

Cypermethrin

Diazinon

CA, KS, OK, WA

Dichlorvos

Dimethoate

Diuron

Malathion

CA, ID

Naphthalene

CA, NH, WA

Oxyfluorfen

Permethrin

Prometryn

Simazine

Trifluralin

Pesticides - listed generically

CA, IN, NY, OH, PA, PR

According to the Office of Water's Impaired Waters and Total Maximum Daily Loads
website there are a total of 72,667 causes of impairments for 303(d) listed waters29. Of these,
approximately 2.4% (a total of 1,774) are listed as pesticides. The majority (73.6% or 1,306 of
the 1,774) of impairments attributed to pesticides are for those no longer registered for use by
EPA. A total of 23%) (415 of the 1,774) of impairments are attributed to currently registered
pesticides, with an additional 3% (53 of the 1,774) of the impairments listed generically for
pesticides, such as for "pesticides" or "organochlorine pesticides." Combined, these two
categories of listings account for 0.6%> (468 of 72,667) of the total causes of impairments for
303(d) listed waters nationally. Additionally, 4,741 impairments are listed for "impaired biota"
and 1,209 impairments are for an "unknown" or "cause unknown - fish kills", which together
account for about 8%> of all impairments.

29 https://www.epa.aov/ceam/303d-listed-impaired-waters

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EPA has compared available CWA 303(d) impairment information regarding water quality
impairments caused by pesticides for states expected to be covered by the PGP with active
ingredient information submitted pursuant to the annual report requirements in the 2016 PGP.
Annual report data for 2017-2019 was examined. EPA found that of the 17 pesticide active
ingredients identified on the relevant 303(d) lists as causes of water quality impairment, 7 of
these pesticides have been cancelled30 and others have significant restrictions. Based on annual
report data,31 none of the 303(d) impairments caused by pesticides in PGP states for the 303(d)
reported years were for pesticides applied under the PGP in those respective states.32

2017 National Water Quality Inventory Report

States, tribes, and territories are required to report biennially on the water quality of
navigable waters in their boundaries, and the extent to which these waters support designated
uses, under Section 305(b) of the Clean Water Act. In the report to Congress33, which was
submitted in August 2017, the Agency summarized the findings of four statistically
representative National Aquatic Resource Surveys and the site-specific assessment results
reported by the states in their Integrated 305(b)/303(d) Reports. States identified a wide range of
assessed waters as not fully supporting at least one of their designated uses. Mercury (primarily
in fish tissue), pathogens, nutrients, PCBs, sediment, and organic enrichment/oxygen depletion
were all cited as leading causes of impairment in assessed waters.

While pesticides are not always monitored when assessing water quality, the Report to
Congress indicated that pesticides were not among the most common causes of impairments
except for the Great Lakes shoreline. "States assessed 4,431 of the nation's 5,000 miles of Great
Lakes shoreline miles. Of these assessed miles, 4,353 were reported as impaired for one or more
designated use. The leading causes of impairment included PCBs, dioxins, and pesticides. The
leading probable sources of impairment were atmospheric deposition, legacy/historical pollution
- primarily contaminated sediment - and agriculture." The Report does not indicate whether any
impairments identified by the states were caused by discharges of pollutants that will be subject
to NPDES permits under the CWA.

30 DDE is also effectively cancelled with the cancellation of DDT.

31 Note that not all aquatic pesticide dischargers are required to submit annual reports. Annual reports are required
from decision-makers required to submit an NOI and who are large entities, and decision-makers with discharges of
pollutants to water containing NMFS listed resources of concern.

32 See sec. 1.1.2.1 of the PGP.

33 https://www.epa.gov/waterdata/2017-national-water-aualitv-inventorv-report-congress

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This document is a prepublication version, signed by all 10 U.S. EPA Regions on November 8, 2023. EPA is submitting it for
publication in the Federal Register. We have taken steps to ensure the accuracy of this version, but it is not the official version.
Notwithstanding the fact that EPA is posting a pre-publication version, the final rule will not be promulgated until published in
the Federal Register.

Interpretation of Monitoring Data Relevant to the PGP

When re-evaluating the registrations of existing pesticides, the Agency considers available
surface-water monitoring data as a line of evidence regarding potential aquatic risk in addition to
considering exposure estimates derived from simulation models. Such monitoring data can
provide a measure of trends in aquatic exposure associated with mitigation measures imposed by
the Agency. For instance, the USGS's 2009 report of Trends of Pesticide Concentrations in
Corn-belt Streams states, "(t)he declines in pesticide concentrations closely followed declines in
their annual applications, indicating that reducing pesticide use is an effective and reliable
strategy for reducing pesticide contamination in streams." Similarly, a study entitled Trends in
pesticide concentrations and use for major rivers of the United States34 found that "pesticides
strongly dominated by agricultural use (cyanazine, alachlor, atrazine and its degradate
deethylatrazine, metolachlor, and carbofuran) has widespread agreement between concentration
trends and use trends" and that "pesticides with substantial use in both agricultural and
nonagricultural applications (simazine, chlorpyrifos, malathion, diazinon and carbaryl) had
concentration trends that were mostly explained by a combination of agricultural use trends,
regulatory changes, and urban use changes inferred from concentrations trends in urban
streams."

Monitoring studies are valuable because they may specifically target areas in which
pesticides considered in the study are likely to be used. This is an effective way of evaluating
impact from mitigation measures, or the increase in use of other pesticides that might replace
pesticides to which mitigation measures are applied.

The best way to interpret the likely causes of pesticide detections in surface water is to
consider any detection in light of the design of the monitoring study itself. For instance, the
USGS's study The Quality of Our Nation's Water - Pesticides in the Nation's Streams and
Ground Water, 1992-2007, described above, used a targeted approach, focusing on areas of
relatively homogenous land-use and environmental settings to relate pesticide occurrence to
individual non-point sources. The sampling was also most intensive during periods of high
pesticide use and runoff. Such a design can best capture transport of pesticide to surface water
from runoff from treated agricultural fields (or treated buildings/lawns) in a watershed. But, the
timing and location of sample collection may not be as effective in capturing residues of
pesticides applied for purposes covered under the General Permit. Concentrations detected could
at times reflect such uses, but the design of the study was meant to capture more diffuse non-
point transport of pesticides in watersheds, and not point source discharge.

Uncertainties with Monitoring Data

The Agency recognizes that monitoring of pesticide levels in water has limitations in its
ability to identify whether use of specific pesticide may adversely affect water quality. The
product monitoring data give only a "snapshot" of the concentration in a particular waterbody at
a particular time. While the USGS (Gilliom et al., 2006) intensified the frequency of its
monitoring during times of the year when most agricultural pesticide usage commonly occurred,
their sampling did not necessarily account for timing of specific pesticide applications, frequency

34 Ryberg and Gilliom, Science of the Total Environment 538 (2015) 431-444, Elsevier B.V.

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of applications, and meteorological events that can cause pesticides to reach surface water as
covered by this permit. Thus, monitoring may not collect a sample when pesticide concentrations
are at peak levels or when present in the water. Moreover, if monitoring detects the presence of a
pesticide, the data usually do not identify the source or if the pesticide residue is actually still a
product serving its intended purpose. Ambient monitoring cannot determine whether the
contamination was due to lawful use (and if so, which one) or unlawful pesticide use, an
accidental spill or discharge of pollutants, or whether the residues detected were from runoff, or
from aquatic uses such as those to be included in the NPDES general permit. Monitoring data are
often difficult to interpret because the ancillary data on pesticide usage in a basin, and factors
that could make the location more or less vulnerable, are often not available.

(3) Technology-based effluent limitations in the PGP provide further protections beyond
compliance with existing FIFRA requirements.

EPA has evaluated available information and expects that the technology-based effluent
limitations are as stringent as necessary to meet applicable WQS. These effluent limitations
require Operators to minimize the discharge of pollutants through the use of the most efficient
and effective means of Pest Management Measures, including pesticide and non-pesticide
methods.

The technology-based effluent limitations require Applicators to minimize the discharge of
pollutants by using only the amount of pesticide and frequency of pesticide application necessary
to control the target pest, maintaining pesticide application equipment in proper operating
condition, and ensuring weather conditions in the treatment area are appropriate for pesticide
application.

The Applicator, to the extent not determined by the Decision-maker, must also use only the
amount of pesticide and frequency of pesticide application necessary to control the target pest,
using equipment and application procedures appropriate for the task.

Certain Decision-makers are also required to more fully assess and implement procedures
to minimize the discharge of pollutants. In this assessment, these Decision-makers must consider
human health and ecological impacts, feasibility, and cost effectiveness and include prevention,
mechanical/physical methods, cultural methods, biological control agents, and as a final resort,
the application of pesticides. To ensure that pollutant discharges are minimized, these Decision-
makers must identify target pest species and areas where those pests occur, identify the possible
sources of the problem, and establish action thresholds or similar measures for implementing
pest management strategies. The technology-based effluent limitations in Part 2.2 of the PGP
also require certain Decision-makers, as appropriate, to analyze surveillance data prior to each
pesticide application to determine when pest action thresholds are met.

The general permit includes several other provisions that the Agency expects to provide
further protections beyond compliance with FIFRA requirements. For instance, Part 4 of the PGP
requires Operators to monitor pesticide applications activities to minimize discharges of
pollutants and during any post-application monitoring to determine effectiveness of the pesticide
application. In addition, Part 6.0 of the PGP contains requirements for all Operators to document
and report adverse incidents involving non-target organisms or the environment, and to take

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corrective action if it is determined that revising Pest Management Measures can help to prevent
future incidents. An adverse incident report calls attention to a situation in which water quality
may be impacted by pesticide use and may indicate that corrective action is required to ensure
that water quality standards are further protected during future applications. The permit also
requires Operators to take corrective actions to eliminate other situations such as unauthorized
releases {i.e., spills or leaks) or the failure to meet applicable water quality standards. These
requirements are discussed further in Part III.6 of this fact sheet. EPA expects this approach will
further reduce discharges of pollutants to waters of the United States from the use patterns
covered under this permit.

(4) Biological pesticides either do not work through a toxic mode of action, or when they
do, are toxic only to a very narrow range of target pest organisms. For chemical pesticides,
the discharges of pollutants covered under this permit are the residues after the pesticide
has performed its intended purpose.

The permit provides coverage for point source discharges of pollutants from certain
applications of pesticides, as identified in Part 1.1.1. of the PGP. Discharges of pollutants from
the application of both chemical and biological pesticides are covered under the permit,
consistent with the Sixth Circuit Court's reading of the CWA term "pollutant" in National
Cotton Council v. EPA.

For chemical or conventional pesticides applied directly to waters {e.g., for aquatic weed
control and aquatic nuisance pest control), it is the pesticide residue, including excess pesticide
that is present outside of the treatment area or within the treatment area once the target pests
have been controlled that is considered a pollutant under the PGP. For any pesticide applied over
water {e.g., mosquito control), any pesticide or pesticide residue that is incidentally deposited in
waters of the United States is considered a pollutant since the intended purpose of the application
is to target pests above the water. Therefore, the concentrations of "pollutants" will be no higher,
and in many instances significantly lower, than the product concentrations considered in EPA's
assessment when the Agency registered the pesticide products for the relevant uses.

Discharges of biological pesticides require permit coverage regardless of whether or not a
residue exists. Biological pesticides or biopesticides are certain types of pesticides derived from
such natural materials as animals, plants, bacteria, and certain minerals. Two classes of
biopesticides are relevant to this permit, microbial pesticides and biochemical pesticides.
Microbial pesticides consist of a microorganism {e.g., a bacterium, fungus, virus, or protozoan)
as the active ingredient. The most widely used microbial pesticides are subspecies and strains of
Bacillus thuringiensis, or Bt which operate by a toxic mode of action, yet they are toxic only to a
very narrow range of target pest organisms (mosquito larvae). Biochemical pesticides, as defined
in 40 CFR 158.2000(a), are naturally occurring substances that control pests by non-toxic
mechanisms. Biochemical pesticides include substances, such as insect sex pheromones that
interfere with mating, as well as naturally-occurring repellants and attractants.

Biopesticides are usually inherently less toxic than conventional pesticides and generally
only affect the target pests and closely related organisms. Often, they are effective in very small
quantities and decompose quickly thereby resulting in lower exposures and largely avoiding the
pollution problems caused by chemical pesticides. When used as a component of Integrated Pest

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Management (IPM) programs, biopesticides can greatly decrease the use of chemical pesticides;
however, use of biopesticides effectively requires users to have a very good understanding of
pest management. Since biochemical pesticides, by regulatory definition, do not work through a
toxic mode of action they may be less likely to result in an excursion of a water quality standard.

(5) The PGP excludes with certain exceptions pesticide applications that result in
discharges of any pesticide to (1) waters impaired for an active ingredient in that pesticide
or a degradate of such active ingredient or (2) any Tier 3 waters Outstanding National
Resource Waters) except for applications made to restore or maintain water quality or to
protect public health or the environment that either do not degrade water quality or only
degrade water quality on a short-term or temporary basis.

EPA identified two scenarios where it finds the PGP may not be adequately protective of
water quality standards and has excluded those discharges of pollutants from coverage under the
permit. Namely, the PGP excludes from coverage: (1) any discharges from a pesticide
application to waters of the United States if the water is identified as impaired by a substance
which either is an active ingredient in that pesticide or is a degradate of such an active ingredient
and (2) discharges of pollutants to Tier 3 Waters (i.e., Outstanding National Resource Waters)
except for pesticide applications made to restore or maintain water quality or to protect public
health or the environment that either do not degrade water quality or only degrade water quality
on a short-term or temporary basis. Any Operator desiring to discharge pollutants in either of
these two scenarios is required to submit an application for an NPDES individual permit. Links
to lists of impaired waters and Tier 3 waters is available at https://www.epa.gov/npdes/pesticide-
permitting. Additional discussion of the basis for these requirements is provided in Part III. 1.1.2
of this fact sheet.

(6) EPA has no evidence in the record that implementation of EPA's PGP has resulted in
documented water quality problems.

EPA has not received any adverse incident reports documenting water quality problems under
EPA's PGP to date. EPA is also not aware of any negative public health or environmental impact
resulting from discharges of pollutants authorized for use under the permit.

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