Pesticides

Pesticides and herbicides are used to control unwanted bugs and plants. Also known as “pests,” these may include insects (ants, wasps), rodents (mice, rats), weeds, or other unwanted organisms. Chemicals used in our yards and gardens can be washed off directly into streams and rivers and harm aquatic life as well as human health.

Pyrethroid Pesticides Impact Water Quality

Pyrethroids are long-lived, synthetic pesticides that interfere with the function of an organism’s nervous system. They kill a wide variety of insect pests, including ants, cockroaches, and lawn grubs, but also earthworms and beneficial insects such as ladybugs and lacewings. When pyrethroids end up in our waters, they can kill crustaceans, aquatic insects, and fish. Products that contain pyrethroids typically have active ingredients that end with the letters “-thrin.” When reading the pesticide label, look for any of the following active ingredients:

• Permethrin
• Bifenthrin
• Cyfluthrin
• Beta-cyfluthrin
• Cypermethrin
• Deltamethrin
• Lambda-cyhalothrin
• Tralomethrin
• Esfenvalerate (an exception to the “-thrin” rule)

If a pyrethroid is an active ingredient, consider other ways to manage the pest, such as less toxic pesticides or controls that do not require the use of a pesticide.

Pesticides and Gardening

Unwanted insects in your lawn, garden, or home can be a source of frustration and damage the plants that you are trying to grow and maintain. Some pests can also potentially transmit disease. To effectively prevent or remove these pests, it is important to understand what is attracting them, how they are entering the home or garden, and the best control for that specific pest. The following small changes made around your home or business can make a big difference in the quality of our local water:

• Identify if a bug is good or bad
• Determine the best method to control pest
• Consider no or less toxic alternatives
• Follow best practices when applying pesticides
• Hire a pest control company that uses Integrated Pest Management practices (IPM) and less toxic approaches

Disposing of Pesticides

Regardless of what the label may state, it is illegal in California to dispose of any amount of pesticide in the trash. Unused pesticides and other household chemicals, including unused medicines, may be taken to the San Joaquin County Hazardous Waste Facility to be disposed of for free.

External Links

Our Water Our World: Pesticides and Water Quality - Pesticides to keep out of our creeks, streams, rivers, bays, and lakes

Our Water Our World: Solve Pest Problems with Less-Toxic Products - Eco-friendly guides in English and Spanish to manage common pests

Our Water Our World: Hiring a Pest Control Company - Guide to identify pest control companies that practice Integrated Pest Management (IPM)

Stockton Water-Wise Gardening - Water-saving plants and tips to manage pests naturally

San Joaquin County Household Hazardous Waste Facility - Free local drop off of household materials like leftover paint, used oil, pool chemicals, expired or unwanted medications

United States Environmental Protection Agency (USEPA) - Ingredients used in pesticides

California Department of Pesticide Regulation (DPR) - Regulates the use and sale of pesticides

This City of Stockton web page last reviewed on --- 6/29/2023