NPDES Permits for the Application of Pesticides 

to Waters of the United States

Allison Wiedeman

Office of Water, US EPA

August, 2009
Outline

 Overview of EPA’s National Pollutant 

Discharge Elimination System (NPDES) 

Pesticides Rule

 6

th Circuit Court’s decision

 Plans to develop General Permits for 

Aquatic Pesticide applications
Application of Pesticides to Waters of the United States 

in Compliance with FIFRA – Final Rule

November 27, 2006

 The application of a pesticide to waters of the United States consistent 

with all relevant requirements under FIFRA does not constitute the 

discharge of a pollutant that requires an NPDES permit in the following 

two circumstances:

1.The application of pesticides directly to waters of the United States in 

order to control pests. Examples of such applications include applications 

to control mosquito larvae, aquatic weeds, or other pests that are present 

in waters of the United States; and 

2.The application of pesticides to control pests that are present over 

waters of the United Sates, including near such waters, where a portion of 

the pesticides will unavoidably be deposited to waters of the United States 

in order to target the pests effectively; for example when insecticides are 

aerially applied to a forest canopy where waters of the United States may 

be present below the canopy or when pesticides are applied over or near 

water for control of adult mosquitoes or other pests.
Litigation on Final Rule

 Petitions for review were filed in 11 Circuit Courts. 

 The petitions were consolidated in the 6th Circuit 

Court of Appeals (National Cotton Council, et al. 

v. EPA).

On January 7, 2009 the 6th Circuit Court issued a 

decision.
6

th Circuit’s Decision

 January 7, 2009 the Court held that:

 The final rule was not a reasonable interpretation 

of the CWA and vacated the rule.

 The Court held that NPDES permits are required for:

(1) All biological pesticide applications that are 

made in or over, including near waters of the U.S. 

(2) Chemical pesticide applications that leave a 

residue or excess pesticide in water when such 

applications are made in or over, including near 

waters of the U.S. 
Response to Court’s Decision

 On April 9th the U.S. Government filed a Motion for Stay of the 

Mandate for a period of two years.

 The Court has granted EPA’s request to stay until April 2011

 The two years will provide EPA time to develop, propose 

and issue final NPDES general permits for unauthorized 

NPDES states, territories and tribes for pesticide 

applications covered under the decision and to provide 

outreach and education to the regulated and 

environmental communities.

 During the stay, EPA will work closely with NPDES 

authorized States to develop their general permits 

concurrent with the development of EPA’s general 

permits to expedite implementation. 
Implications of 6th Circuit’s Decision

 Irrigation return flows and agricultural runoff will not require NPDES 

permits as they are specifically exempted from the CWA.

 At least the following large categories are covered by Court’s decision 

when sprayed to, over, or near waters of the U.S:

 Mosquito larvicides;

 Mosquito adulticides;

 Herbicides used to control weeds in lakes and ponds;

 Herbicides used to control weeds in irrigation systems and other 

waterways;

 Herbicides used to control weeds along ditch banks in agricultural 

drainage systems;

 Insecticides used in wide-area insect suppression programs;

 Herbicides used in wide-area control programs directed at aquatic 

invasive plant species;

 Herbicides, insecticides and other pesticides used in forestry 

programs when applied over waters of the U.S.

 Products applied to kill fish, mussels, or other invasive aquatic 

species
Example: Aerial 

Mosquito Control
Example: Weed and Insect Control Near Water
Example: Direct Application to Water for Aquatic Pests
Agricultural Stormwater; Exempt by Statute
Irrigation Return Flow; Exempt by Statute
Example: Off-Target Spray Drift. Not covered by 2006 Rule
Implications of 6th Circuit’s Decision

 OPP estimates that approximately 5.6 

million such applications annually are 

performed by 365,000 applicators for 

these types of pesticide uses.

 500 different pesticide active 

ingredients are contained in 

approximately 3,700 product labels.
Implementation

 EPA’s General Permit will cover pesticide 

applications in AK, MA, ID, NH, and NM

 During the stay, EPA will work closely with the 46 

NPDES authorized States to concurrently develop 

their general permits. 

 Will provide outreach and education to the regulated 

and environmental communities.

 Since the court decision, EPA has been reviewing 

the 23 existing state pesticide application permits, 

initiated data gathering, scoped out a road map for 

developing the NPDES permits. 
State Regulatory Workgroup

 Purpose: To exchange information during the permit 

development processes, and to facilitate 

simultaneous general permit development for EPA 

and the states

 Members: Reps from the Association of State and 

Interstate Water Pollution Control Agencies 

(ASIWPCA) and the

American Association of Pesticide Control Officials 

(AAPCO) 

 Meet via conference call every 4 – 6 weeks
Schedule

2 mo. 8 mo. 8 mo. 4 mo.
General Permit Prototype

 Purpose: “reality check” prior to formal proposal

 For: One for mosquitocides, and one for herbicides 

to lakes and ponds

 When: 

 Available to state WG in late summer, 2009

 Available to PPDC (EPA FACA) in October, 2009

 How: No formal public comment or response, rather 

will receive input to improve the proposal

 Next Steps: will apply lessons learned to remaining 

6 pesticide use categories
General Permits

 General Permit

 1 permit issued per state many applications 

submitted

 Appropriate where

 multiple, similar sources (e.g., same category

or similar process) within the same 

geographic area require permit coverage

 sources have similar discharges and would 

require the same or similar permit conditions
Process for GP Coverage

 Permittee must complete an electronic form called 

“Notice of Intent” (NOI)

 Information required in an NOI

 Area of coverage

 Sources covered

 Address of permittee

 Submit NOI and coverage begins

 Covered for 5 years
Issues to be Considered

 Who must apply for the Pesticides permit?

 What will be required in a permit?

Effluent Limitations ?

 Water Quality Standards?

 Monitoring?

 Reporting?

 Others?
Questions ?