Metals
Thallium in U.S. tap water
61 public water systems across 10 U.S. states report Thallium in their annual Consumer Confidence Report. 3 sit at or above the federal limit.
At or above the federal limit (3)
| Water system | Measured | vs. limit |
|---|---|---|
| Hialeah, FL 2023 annual report | 0–0.009 mg/L | 4.5× the limit |
| Winton Water & Sanitary Dist — Winton, Ca, CA 2023 annual report | 5 ug/L | 2.5× the limit |
| Gonzales, City of — Gonzales, Ca, CA 2022 annual report | 2 ug/L | 1.0× the limit |
Approaching the limit (3)
| Water system | Measured | vs. limit |
|---|---|---|
| City of Paso Robles Water Division — Paso Robles, Ca, CA 2023 annual report | 0–1.8 ug/L | 0.9× the limit |
| Santa Ynez River Water Cons. Dist. Id#1 — Santa Ynez, Ca, CA 2023 annual report | 0–1.6 ug/L | 0.8× the limit |
| Solvang Water Division — Solvang, Ca, CA 2023 annual report | 0–1.6 ug/L | 0.8× the limit |
Within the federal limit (55)
| Water system | Measured |
|---|---|
| Camp Williams-resort Water — Manhattan Beach, Ca, CA 2020 annual report | 1 ug/L |
| Camp Williams-resort Water — Manhattan Beach, Ca, CA 2021 annual report | 1 ug/L |
| Loma Linda, City of — Loma Linda, Ca, CA 2023 annual report | 0.4–0.55 ug/L |
| St George, UT 2024 annual report | 0–0.5 ug/L |
| Chandler, AZ 2024 annual report | 0.15 ug/L |
| Peoria, AZ 2024 annual report | 0.12 ug/L |
| West Valley City, UT 2024 annual report | 0.05 ug/L |
| City of Hialeah, FL 2023 annual report | 0.01–0.02 ug/L |
| City of North Miami Beach, FL 2023 annual report | 0.01–0.02 ug/L |
| Miami Dade, FL 2023 annual report | 0.01–0.02 ug/L |
| Salt Lake City, UT 2024 annual report | 0.00002 mg/L |
| Antelope Valley East Kern Water Agency — Palmdale, Ca, CA 2023 annual report | Not detected ug/L |
| Antelope Valley East Kern Water Agency — Palmdale, Ca, CA 2020 annual report | Not detected ug/L |
| Antelope Valley East Kern Water Agency — Palmdale, Ca, CA 2021 annual report | Not detected ug/L |
| Antelope Valley East Kern Water Agency — Palmdale, Ca, CA 2022 annual report | Not detected ug/L |
| Birmingham, AL 2024 annual report | Not detected mg/L |
| Boron Csd — Boron, Ca, CA 2022 annual report | Not detected ug/L |
| City of Hampton, VA 2024 annual report | Not detected ug/L |
| City of Newport News, VA 2025 annual report | Not detected ug/L |
| City of Poquoson, VA 2024 annual report | Not detected ug/L |
| City of Poquoson, VA 2025 annual report | Not detected ug/L |
| City of West Sacramento — West Sacramento, Ca, CA 2022 annual report | Not detected ug/L |
| Cleveland, OH 2024 annual report | Not detected mg/L |
| Columbus, OH 2025 annual report | Not detected mg/L |
| Covina Irrigating Co. — West Covina, Ca, CA 2023 annual report | Not detected ug/L |
| Covina Irrigating Co. — West Covina, Ca, CA 2020 annual report | Not detected ug/L |
| Covina Irrigating Co. — West Covina, Ca, CA 2021 annual report | Not detected ug/L |
| Foothill Municipal Water Dist. — La Canada Flintridge, Ca, CA 2023 annual report | Not detected ug/L |
| Garland, TX 2024 annual report | 0–0 ug/L |
| Hampton, VA 2025 annual report | Not detected ug/L |
| High Point, NC 2024 annual report | Not detected ug/L |
| James City County, VA 2025 annual report | Not detected ug/L |
| Lukins Brothers Water Company — South Lake Tahoe, Ca, CA 2022 annual report | Not detected ug/L |
| Mobile, AL 2024 annual report | Not detected ug/L |
| Mojave Pud — Mojave, Ca, CA 2023 annual report | Not detected ug/L |
| Montgomery, AL 2024 annual report | Not detected mg/L |
| Nashville, TN 2023 annual report | Not detected mg/L |
| Newport News, VA 2024 annual report | Not detected ug/L |
| North Gualala Water Company — Gualala, Ca, CA 2023 annual report | Not detected ug/L |
| North Tahoe Pud - Main — Tahoe Vista, Ca, CA 2021 annual report | Not detected mg/L |
| Plano, TX 2024 annual report | 0–0 ug/L |
| South Tahoe Pud - Main — South Lake Tahoe, Ca, CA 2023 annual report | Not detected ug/L |
| Thermalito Water & Sewer Dist — Oroville, Ca, CA 2023 annual report | Not detected ug/L |
| Three Valleys MWD — Claremont, Ca, CA 2023 annual report | Not detected ug/L |
| Thunderbird Cwd — Apple Valley, Ca, CA 2023 annual report | 0 ug/L |
| West Jordan, UT 2024 annual report | Not detected ug/L |
| Westside Park Mutual Water — Palmdale, Ca, CA 2023 annual report | Not detected ug/L |
| White Fence Farms Mwc No. 1 — Palmdale, Ca, CA 2021 annual report | Not detected ug/L |
| White Fence Farms Mwc No. 1 — Palmdale, Ca, CA 2023 annual report | Not detected ug/L |
| White Fence Farms Mwc No. 1 — Palmdale, Ca, CA 2020 annual report | Not detected ug/L |
Showing 50 of 55. The full list is in the JSON API.
Thallium by state
Every state where a public water system reports Thallium in its annual report, ranked by systems at or above the federal limit.
Frequently asked
+What is Thallium?
Thallium is a contaminant some U.S. public water utilities measure and report in their annual Consumer Confidence Report.
+What is the federal limit for Thallium in drinking water?
The federal MCL for Thallium is 0.002 mg/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 Thallium over the federal limit?
3 of the 61 public water systems on The Water Map report Thallium at or above its federal limit, spanning 10 U.S. states. The full list is on this page.
+Which states report the most Thallium in their drinking water?
Of the systems on The Water Map, California (2 systems at or above the limit), Florida (1 system at or above the limit) report the most Thallium exceedances. The state-by-state table on this page lists every state.
+How can I check if Thallium 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 Thallium.