Project Purpose

Despite California's data-rich environment, there are still many obstacles when trying to access and understand pesticide data at the nexus of water quality, ecological effects, and human health. We recognize a need to fill data gaps, not necessarily by collecting new data, but by better leveraging information already technically in the public domain. The goal of this project is to bring pesticide reporting, occurrence, and toxicity data together in ways that yield insights and meet the expressed needs of stakeholders in clear, efficient, credible, and repeatable ways.


While the overall quantity of pesticides used in California has not changed much since the 1990s, the types of insecticides most heavily applied today tend to have much higher aquatic toxicity, which brings the potential for increased effects on aquatic ecosystems. Agriculture is also intensifying across California, with conversion to high-value, high-input crops, for which profit is maximized with pesticide application. Multiple water bodies in California have been classified as having one or more beneficial uses impaired by pesticides, and the Water Boards have started to mandate development of Total Maximum Daily Loads to reduce pesticide loading and restore beneficial uses. Unfortunately, current single-pesticide-focused regulatory actions inadvertently incentivize shifts from the use of an identified “bad actor” pesticides to newer pesticides that often turn out to be equally problematic from the aquatic toxicity perspective (for example, the recent shift from organophosphates to pyrethroids and neonicotinoids).

Pesticide Data Visualization Tool

Our project seeks to empower decision makers at the local, regional, and statewide level with the information they need to adequately understand and manage pesticide use from multiple perspectives. California has long had the most progressive pesticide application data reporting system in the world, but the information collected remains difficult and time-consuming to access and analyze. 

To this end, we have created an easy to use, web-based data visualization and mapping tool that integrates existing pesticide use and water quality data for California. Combining information from multiple data sets will maximize their utility, allowing for comprehensive analysis of the effects of pesticide use, which can inform an evaluation of the most effective management actions and policy or regulatory changes.

We are focusing the initial phase of tool development on surface water quality and ecological impacts. Subsequent project development will incorporate groundwater and potential human health impacts when groundwater serves as a source of drinking water, by linking the tool to specific mapping efforts underway by others such as the California Department of Public Health and the Community Water Center. 

The tool will help to facilitate a common view among disparate stakeholders, including community groups, NGOs, public employees, farmers and agricultural groups, academics, consultants, and the public. Tool users will visualize links among sources, concentrations in water and sediment, and ecological and human health, which will in turn advance further quantitative spatiotemporal analyses.

Our Approach

The project vision, outlined in a workplan by American Rivers, calls for a technology solution that taps into available data repositories and makes "valuable data more easily accessible to decision-makers and others by creating an easy-to-use, web-based tool that will enable visualization and download of high-resolution geographic and temporal pesticide-related data." SFEI is building upon the vision to refine the workplan to offer a more specific and actionable plan with sufficient level of detail that can inform technical action.

We will remain engaged with an interested stakeholder group while leveraging a team of expert advisors. Consistent with this approach is the development of a more detailed description of a user engagement strategy, coupled with a phased approach to software development that can effectively produce a suite of visualization tools designed to meet stakeholder needs.


Phase I (through July 2023)
  • Refine the available workplan
  • Detail phases and a roadmap for product development
  • Develop data analysis models
  • Develop data processing scripts and standard operating procedures
  • Develop a data visualization and distribution prototype that meets stakeholder needs
  • Develop technical documentation and training and outreach materials
  • Address pressing information gaps
  • Develop a sustainability plan for continuity of funding support
2019 to 2023
Lisa Hunt
Programs and Focus Areas: 
Contaminants of Emerging Concern
Environmental Informatics Program
Location Information
General Project Location(s):