What’s in your waterway? Imidacloprid Water Contamination Map of Urban Areas in California

Clean water

Ben Grundy | TPIN

Neonicotinoids, “neonics” for short, are a class of insecticides linked to bee die-offs. These pesticides disrupt the nervous system of bees and other insects and can cause paralysis and death. Research also shows that neonics can harm the development of baby bee brains

In 1991, imidacloprid became the first neonicotinoid registered for use. In this map, we look at water contamination from imidacloprid. 

According to the California Department of Pesticide Regulation (DPR), there are 253 pesticide products registered for use in California that contain imidacloprid. This insecticide can remain in the soil for long periods of time and be transported by rain or irrigation systems, which leads to contamination in California’s water. 

Water sampling conducted by DPR found that 92% of urban water samples in Los Angeles, Orange, and San Diego County and 58% in urban areas of Alameda, Contra Costa, Placer, Sacramento, and Santa Clara County contained imidacloprid at levels above EPA’s chronic benchmark for harm to aquatic ecosystems.

Explore the map and graph below to see your community’s imidacloprid contamination levels in waterways. And take action to address urban use of neonics, by calling on Gov. Newsom to sign AB 2146 by the end of September. 

Read our press release here.

Imidacloprid Water Contamination Map

This map shows surface water imidacloprid data from 2000 – 2020. Shading on counties indicates the percentage of samples in that county that contain imidacloprid. Hover over a county to view a pop-up window displaying the date range of samples, the concentration range of imidacloprid detected, and the total number of samples tested.

The bar chart shows the number of samples that were tested per year. Dark blue indicates that the sample did not contain imidacloprid and light blue indicates that the sample does contain imidacloprid. Very few samples were tested for imidacloprid prior to 2010. The percentage of samples that detect imidacloprid remains fairly constant over time. Select a county using the dropdown above the chart to view data for just that county.

Raw data can be accessed from the California Department of Pesticide Regulation’s Surface Water Database (SURF) using the following link: https://www.cdpr.ca.gov/docs/emon/surfwtr/surfcont.htm

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