1,2,3-Trichloropropane (TCP) in drinking water
An industrial solvent and soil fumigant impurity. California limit 0.005 ppb.
Health: Likely carcinogen.
Across the US
Those 65 systems serve about 6.3 million people.
From EPA's earlier unregulated contaminant testing (UCMR 3). These results are older, so ask your utility for current data.
Highest results
| Water system | People | Highest result |
|---|---|---|
| Suffolk County Water Authority | 1.1 million | 1.02 ppb |
| City of Livingston | 14,894 | 0.64 ppb |
| Garden City Park Water District | 18,000 | 0.51 ppb |
| Waipahu-Ewa-Waianae Water System | 217,479 | 0.44 ppb |
| Greenlawn Water District | 42,000 | 0.35 ppb |
| Riverhead Water District | 35,000 | 0.32 ppb |
| City of Bakersfield | 171,108 | 0.31 ppb |
| Waipio Heights Water System | 11,516 | 0.31 ppb |
| Immokalee Water | 26,841 | 0.28 ppb |
| City of Wasco | 22,757 | 0.28 ppb |
| City of Shafter | 21,915 | 0.28 ppb |
| Jericho Water District | 58,000 | 0.25 ppb |
| Waialua-Haleiwa Water System | 9,996 | 0.22 ppb |
| Dix Hills Water District | 34,522 | 0.2 ppb |
| Arvin Community Services District | 19,669 | 0.19 ppb |
| California State University Fresno Water System | 1,500 | 0.19 ppb |
| City of Atwater | 29,479 | 0.18 ppb |
| Kalaheo-Koloa Water System | 12,660 | 0.17 ppb |
| Aqua Pennsylvania Main System | 822,600 | 0.17 ppb |
| California Water Service – Bakersfield | 268,129 | 0.16 ppb |
| PRASA – Almirante Norte | 4,285 | 0.16 ppb |
| City of Fresno | 545,970 | 0.15 ppb |
| City of Parlier | 14,576 | 0.15 ppb |
| City of Modesto | 218,915 | 0.14 ppb |
| PRASA – Sabana Hoyos | 2,360 | 0.13 ppb |
States with the most detections
- California: 30
- New York: 10
- Hawaii: 8
- Puerto Rico: 5
- Florida: 2
- Connecticut: 2
- Alabama: 2
- New Jersey: 2
- Pennsylvania: 1
- New Mexico: 1
- Maryland: 1
- Arizona: 1
Sources
The limits, health goals and health effects on this page come from these EPA sources. The results come from EPA's monitoring data for each water system.
- EPA: UCMR occurrence data (the test results)
- EPA: National Primary Drinking Water Regulations (limits and health effects table)
This page summarizes public regulatory information. It is not medical advice. How we source and check this site.
Questions
What is the safe level of 1,2,3-Trichloropropane (TCP) in drinking water?
There is no federal legal limit. EPA cancer risk level (1 in a million): 0.0004 ppb.
How do I remove 1,2,3-Trichloropropane (TCP) from tap water?
See the filter guidance on this page: look for a product certified for 1,2,3-Trichloropropane (TCP) specifically, and check the claim in NSF's certified product listings.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.