Other
Diquat in U.S. tap water
121 public water systems across 1 U.S. states report Diquat in their annual Consumer Confidence Report. None currently sit at or above the federal limit.
Within the federal limit (121)
| Water system | Measured |
|---|---|
| San Gabriel Valley Wc - Fontana, CA 2023 annual report | 4.2 UG/L |
| Contra Costa Water District, CA 2023 annual report | 0.1075 UG/L |
| Bakersfield, CA 2024 annual report | Not detected UG/L |
| Brentwood, CA 2025 annual report | Not detected UG/L |
| Brentwood, CA 2023 annual report | Not detected UG/L |
| Brentwood, CA 2024 annual report | Not detected UG/L |
| Burbank, CA 2024 annual report | Not detected UG/L |
| Burbank-city, Water Dept., CA 2026 annual report | Not detected UG/L |
| Burbank-city, Water Dept., CA 2025 annual report | Not detected UG/L |
| Burbank-city, Water Dept., CA 2023 annual report | Not detected UG/L |
| Cal-water Service Co.-chico, CA 2025 annual report | Not detected UG/L |
| Cal-water Service Co.-chico, CA 2023 annual report | Not detected UG/L |
| City of Antioch, CA 2024 annual report | Not detected UG/L |
| City of Antioch, CA 2023 annual report | Not detected UG/L |
| City of Antioch, CA 2025 annual report | Not detected UG/L |
| City of Cupertino, CA 2023 annual report | Not detected UG/L |
| City of Cupertino, CA 2026 annual report | Not detected UG/L |
| City of Daly City, CA 2025 annual report | Not detected UG/L |
| City of Daly City, CA 2026 annual report | Not detected UG/L |
| City of Daly City, CA 2023 annual report | Not detected UG/L |
| City of Fairfield, CA 2025 annual report | Not detected UG/L |
| City of Fairfield, CA 2023 annual report | Not detected UG/L |
| City of Hayward, CA 2026 annual report | Not detected UG/L |
| City of Hemet, CA 2024 annual report | Not detected UG/L |
| City of Martinez, CA 2025 annual report | Not detected UG/L |
| City of Martinez, CA 2024 annual report | Not detected UG/L |
| City of Murrieta, CA 2024 annual report | Not detected UG/L |
| City of Perris, CA 2024 annual report | Not detected UG/L |
| City of Pittsburg, CA 2024 annual report | Not detected UG/L |
| City of Pittsburg, CA 2026 annual report | Not detected UG/L |
| City of San Jacinto, CA 2024 annual report | Not detected UG/L |
| City of San Jose - Evg/edv/coy, CA 2023 annual report | Not detected UG/L |
| City of San Jose - Evg/edv/coy, CA 2026 annual report | Not detected UG/L |
| City of Santa Clara, CA 2023 annual report | Not detected UG/L |
| City of Santa Clara, CA 2025 annual report | Not detected UG/L |
| City of Stockton, CA 2023 annual report | Not detected UG/L |
| City of Stockton, CA 2025 annual report | Not detected UG/L |
| City of Vacaville, CA 2026 annual report | Not detected UG/L |
| City of Vacaville, CA 2025 annual report | Not detected UG/L |
| City of Vacaville, CA 2023 annual report | Not detected UG/L |
| City of Vallejo, CA 2025 annual report | Not detected UG/L |
| City of Vallejo, CA 2023 annual report | Not detected UG/L |
| Concord, CA 2024 annual report | Not detected UG/L |
| Contra Costa Water District, CA 2025 annual report | Not detected UG/L |
| Contra Costa Water District, CA 2026 annual report | Not detected UG/L |
| Cws - Visalia, CA 2025 annual report | Not detected UG/L |
| Cwsc Salinas, CA 2023 annual report | Not detected UG/L |
| Cwsc Salinas, CA 2025 annual report | Not detected UG/L |
| Cwsc Salinas, CA 2024 annual report | Not detected UG/L |
| Cwsc Salinas, CA 2026 annual report | Not detected UG/L |
Showing 50 of 121. The full list is in the JSON API.
Frequently asked
+What is Diquat?
Diquat is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+What is the federal limit for Diquat in drinking water?
The federal MCL for Diquat is 20 UG/L. The EPA enforces this against the regulated reporting statistic (typically a running annual average or 90th percentile), not a single-sample spike.
+How many U.S. water systems have Diquat over the federal limit?
Zero of the 121 public water systems in The Water Map dataset currently report Diquat at or above its federal limit.
+How can I check if Diquat is in my city's tap water?
Search your city on The Water Map (https://www.thewatermap.com/) or browse the list on this page. Every U.S. public water utility is required to publish an annual Consumer Confidence Report that lists every contaminant it measured, including Diquat.