Aquatic Pesticides

The application of pesticides onto Delaware surface water requires a permit from the Department of Natural Resources and Environmental Control (DNREC). Permits for this activity are part of the National Pollutant Discharge Elimination System (NPDES).

DNREC has published a draft National Pollutant Discharge Elimination System (NPDES) General Permit for the application of Aquatic Pesticides.

Draft NPDES Permit Number DE 0051241

Draft Fact Sheet regarding Permit Number DE 0051241

In 2009, the U.S. Sixth Circuit Court determined that the application of biological pesticides and chemical pesticides with residuals to waters regulated under the provisions of the federal Clean Water Act (CWA) must be regulated by a National Pollutant Discharge Elimination Program (NPDES) permit. On September 11, 2012, DNREC adopted the Regulations Governing the Discharges from the Application of Pesticides to Waters of the State as Subsection 9.8 (PDF) of the Regulations Governing the Control of Water Pollution (7 DE Admin. Code 7201).

The regulations cover discharges of biological pesticides and chemical pesticides that leave a residue, from the following pesticide use patterns: mosquito and other flying insect pest control, weed and algae control, animal pest control, and forest canopy pest control.


Adverse Incident Form

Annual Report

Notice of Intent Form

Notice of Intent Instructions

Notice of Termination Form

Notice of Termination Instructions

Related Links

Department of Agriculture, Pesticide Management

Division of Fish & Wildlife, Pond Management

Questions and Answers

“Waters of the State” or “State Waters” means all water, on the surface and under the ground, wholly or partially within, or bordering the State, or within its jurisdiction including but not limited to:

  1. waters which are subject to the ebb and flow of the tide including, but not limited to, estuaries, bays and the Atlantic Ocean;
  2. all interstate waters, including interstate wetlands;
  3. all other Waters of the State, such as lakes, rivers, streams (including intermittent and ephemeral streams), drainage ditches, tax ditches, creeks, mudflats, sand flats, wetlands, sloughs, or natural or impounded ponds;
  4. all impoundments of waters otherwise defined as Waters of the State under this definition; and
  5. wetlands adjacent to waters (other than waters that are themselves wetlands) identified in the above four statements.

Although waste and stormwater treatment systems or waste storage structures including, but not limited to, treatment ponds or lagoons designed to meet the requirements of the Clean Water Act (other than cooling ponds which otherwise meet the requirements of this definition) are not considered to be “Waters of the State”, coverage will be required if they are determined to discharge into Waters of the State.

Operators required to get a permit include:

  1. A private applicator who purchases and applies “restricted use” pesticides;
  2. A commercial applicator (for hire) who uses any pesticides on other’s property in exchange for compensation; or,
  3. A commercial applicator (not for hire) who uses any pesticides as part of their job duties.

The pesticide certification classes that will apply include: Forestry (02), Aquatic (5A), Mosquito (5C), and Right of Way (06).

Permit coverage can be obtained, free of charge, by filling out the one page form called a Notice of Intent (NOI).

The form should be filled out by (1) Any entity who performs the application of pesticides; or (2) Any entity who has day-to-day control of the application (i.e., they are authorized to direct workers for hire to carry out those activities). Permit coverage is valid up to a period of five years. A new NOI must be submitted (within 30 days) if an operator who has previously submitted an NOI undergoes a name change or if there is a change in ownership. Changes in operations including the change in active ingredients for products used, or change in Pest Management Area, as indicated on the NOI, will require a new NOI.

A Pesticide Discharge Management Plan (PDMP) must be developed for all state government entities, any operator that serves a population of more than 10,000, or a private enterprise that exceeds the Small Business administration size standard as identified at 13 CFR 121.201 (size standards set by North American Industry Classification System codes, varies by industry type). PDMPs are kept with the operator (not submitted to the Department). Please refer to the regulation in entirety for the mandated contents of the PDMP.

Operators must keep written records covered under this regulation for five years. Please refer to the entire regulation, subsections – for the list of records.

Immediately notify the Department of spills and leaks by calling the Spill Notification 24-hour Hotline: (800) 662-8802. Within 30 days of a reportable adverse incident or health to humans or the environment, operators must provide a written report of the adverse incident to the Department. Please refer to the regulation, in full, to see the definition of Adverse Incident.

PDMPs are not to be submitted to the Department, but kept with the Operator. Only those Operators who are required to develop a PDMP will be required to submit annual reports. The annual report must be submitted no later than February 1 of the following year for all pesticide activities covered under this Subsection occurring during the previous calendar year.