1D – Pest and Weed Management

Management Measure

To reduce contamination of surface water and ground water from pesticides

  1. Evaluate the pest problems, previous pest control measures, and cropping history.
  2. Evaluate the soil and physical characteristics of the site including mixing, loading, and storage areas for potential leaching or runoff of pesticides. If leaching or runoff is found to occur, steps should be taken to prevent further contamination.
  3. Use integrated pest management (IPM) strategies that (a) apply pesticides only when an economic benefit to the producer will be achieved (i.e., applications based on economic thresholds), and (b) apply pesticides efficiently and at a time when runoff losses are unlikely.
  4. When pesticides applications are necessary and a choice of registered materials exists, consider the persistence, toxicity, runoff potential, and leaching potential of products.
  5. Periodically calibrate pesticide spray equipment.
  6. Use anti-blackflow devices on hoses used for filling tank mixtures.

Management Practices

The purpose of this management measure is to reduce or eliminate pesticide runoff into surface water. The most effective approach is to apply pesticides as prescribed on the label with respect to timing and rate of chemical application. The following practices should be considered to reduce the likelihood that pesticides will pollute surface and ground water.

  • Evaluate pest control needs
    Determine the extent of the pest problems, previous pest control measures, and cropping history. Consider using integrated pest management (IPM) to reduce the amount of chemicals needed to manage pest damage. See the University of California Statewide Integrated Pest Management Program. Pest management practices should be updated when crop rotation, pest problems, or type of pesticide used has changed.
  • Reduce the risk of accidental spills
    Know the physical and soil characteristics of the area and evaluate the site for runoff potential to surface water and leaching potential to ground water. Note the location and proximity of the mixing, loading, and storage areas relative to surface water. Use anti-backflow devices on hoses used for filling tank mixtures and on chemigation systems.
  • Maintain application equipment
    Calibrate application equipment once a season and inspect application equipment for wear and damage.
  • Follow the label
    Apply and use pesticides as prescribed on the label and at times when leaching and runoff are least likely (not just before a rainstorm).
  • Protect surface waters from spills and contaminated runoff
    Install perimeter controls such as vegetative buffers to help prevent pesticide runoff into streams.


  • City of San Francisco, IPM Program minimizes pesticide use through use of alternative pest and weed control strategies. One of the things they have done is to revise landscaping to prevent growth of problem weeds in the first place – by planting groundcovers.
  • California Pesticide Management Plan for Water Quality is a joint effort by DPR and the SWRCB to protect water quality from the potential adverse effects of pesticides. It describes how DPR and the County Agricultural Commissioners work in cooperation with the SWRCB and the Regional Water Quality Control Boards (RWQCBs) to protect water quality from the use of pesticides.
  • Coalition for Urban/Rural Environmental Stewardship (CURES) has two programs to promote the environmental friendly use of pesticides. The Water Steward Orchard Program is designed to promote awareness of pesticide runoff from products used in dormant orchard sprays. The Water Steward Rice Program is a rice pesticide stewardship plan launched by CURES, the California Rice Commission, and a broad coalition of grower and industry interests. The purpose of this program is to raise awareness of rice pesticides and impacts on the drinking water quality of the Sacramento River.
  • Department of Pesticide Regulation (DPR) Pest Management Alliance Program provides support for agricultural, nonagricultural, and urban groups to develop and demonstrate pest management systems that reduce risks associated with pesticide use, including risks to surface and ground waters. The Web site has Alliance project evaluations, reports, and other technical information available for pest management systems in various commodities such as almonds, stone fruit, and strawberries.
  • DPRs Ground Water Quality Program addresses both agricultural and nonagricultural sources of pesticide residues in ground waters. The DPR is proposing to revise the Ground Water Quality Program by changing the current ground water regulations.
  • DPRs Surface Water Quality Program addresses both agricultural and nonagricultural sources of pesticide residues in surface waters. It has preventive and response components that reduce the presence of pesticides in surface waters. The preventive component includes local outreach to promote management practices that reduce pesticide runoff. Prevention also relies on DPR’s registration process in which potential adverse effects on surface water quality, particularly those in high-risk situations, are evaluated. The response component includes mitigation options to meet water quality goals, recognizing the value of self-regulating efforts to reduce pesticides in surface water as well as the regulatory authorities of DPR, the SWRCB, and the RWQCBs.
  • University of California Statewide Integrated Pest Management Program contains information for practitioners on how to identify and manage pests, including educational resources, databases, publications, projects, and other resources.

Information Resources

  • DPR Fate Reviews contains environmental fate reviews for many pesticides that are used in agriculture, including diuron, methoprene, and pyrethrums.
  • Community Alliance with Family Farmers, Hedgerows for California Agriculture: A Resource Guide this resource guidebooks includes information about using hedgerows and related practices as tools to increase groundcover and reduce soil erosion and to improve pesticide management. This guide includes information on the benefits of hedgerows, practical information about installing hedgerows, and other relevant reference materials.
  • Conservation Technology Information Center (CTIC) is a national, public-private partnership that envisions agriculture using environmentally beneficial and economically viable natural resource systems. CTIC’s mission to provide reliable, profitable solutions to improve the relationship between agriculture and the environment.
  • Florida Department of Agriculture and Consumer Services and Florida Department of Environmental Protection, Best Management Practices for Agrichemical Handling and Farm Equipment Maintenance. The purpose of this document is to familiarize farmers, farm managers, and farm workers about Best Management Practices (BMPs) and pollution prevention actions that can be implemented at farm maintenance areas to further protect the environment and improve the efficiency of the farm.
  • Western Integrated Pest Management Center is one of four centers in a national network established to strengthen USDA's connection with production agriculture, research and extension programs, and agricultural stakeholders throughout the United States.
  • University of California Cooperative Extension Service, Pests of Agricultural Crops, Floriculture and Ornamental Nurseries, and Commercial Turfgrass, University of California Pest Management Guidelines includes guidelines for pest management in California.
  • University of California Statewide Integrated Pest Management Program, Dormant Spray Alternatives Calculator estimates the costs of using organophosphate dormant sprays and selected alternative practices. When compared to conventional organophosphate dormant sprays, the alternatives listed in the calculator offer favorable levels of pest control efficacy with comparable ranges of cost, while affording a reduced risk of aquatic toxicity.
  • University of Illinois, College of Agriculture, Cooperative Extension Service, 50 Ways Farms Can Protect Their Groundwater. This Web site provides information on how to reduce contamination of ground water from fertilizers, herbicides, and insecticides; how to use integrated pest management; and how to improve chemical application.
  • University of Illinois, College of Agriculture, Cooperative Extension Service, 60 Ways Farmers Can Protect Their Surface Water includes information on reducing insecticide and pesticide use, selecting appropriate pesticides, and handling pesticides safely and efficiently.


USDA. No date. Electronic Field Office Technical Guide for California. U.S. Department of Agriculture, Natural Resource Conservation Service.

USEPA. 2002. Chapter 4: Management Measures. In National Management Measures for the Control of Nonpoint Pollution from Agriculture. U.S. Environmental Protection Agency, Washington, DC.

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