National Drinking Water Database
City of Riverside Public Utilities Utilities - Riverside, CA
Serves 280,832 people
Radon
Radon is a radioactive breakdown product of radium and uranium in soil, rock and water; it is often present in groundwater.Testing Summary
| Contaminant | Average/ Maximum Result | Health Limit Exceeded | Legal Limit Exceeded | Testing History -Tested  -Detected  -Over Health Guidelines  -Over Legal Limit* |
|---|---|---|---|---|
| RadonRadon is a radioactive breakdown product of radium and uranium in soil, rock and water; it is often present in groundwater. | 350.07 pCi/L 548 pCi/L | Yes 1.5 pCi/L | Legal at any levelThis is the Federal Limit. State Limits may be lower. |  |
| NOTE: Each dot in the above graph represents one month. * Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance. | ||||
Health Based and Legal Limits for Radon
Health Based Limits for Radon
| Standard | Description | Level |
|---|---|---|
| One in one million (10-6) Cancer Risk | The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 1,000,000. Source: U.S. Environmental Protection Agency. | 1.5 pCi/L |
| One in ten thousand (10-4) Cancer Risk | The concentration of a chemical in drinking water corresponding to an excess estimated lifetime cancer risk of 1 in 10,000. Source: U.S. Environmental Protection Agency. | 150 pCi/L |
Testing Results
| Testing Date | Average Result | Samples taken that day | Number of Non-Detects | Range of Results |
|---|---|---|---|---|
| 2008-07-15 | 311 pCi/L | 1 | 0 | 311 pCi/L |
| 2008-06-24 | 269 pCi/L | 1 | 0 | 269 pCi/L |
| 2008-03-26 | 181 pCi/L | 1 | 0 | 181 pCi/L |
| 2007-09-25 | 231 pCi/L | 1 | 0 | 231 pCi/L |
| 2007-07-10 | 508 pCi/L | 1 | 0 | 508 pCi/L |
| 2007-06-28 | 548 pCi/L | 1 | 0 | 548 pCi/L |
| 2007-03-21 | 389 pCi/L | 1 | 0 | 389 pCi/L |
| 2006-12-27 | 302 pCi/L | 1 | 0 | 302 pCi/L |
| 2006-10-11 | 213 pCi/L | 1 | 0 | 213 pCi/L |
| 2006-07-13 | 299 pCi/L | 1 | 0 | 299 pCi/L |
| 2005-09-29 | 310 pCi/L | 1 | 0 | 310 pCi/L |
| 2005-07-19 | 440 pCi/L | 1 | 0 | 440 pCi/L |
| 2005-03-24 | 280 pCi/L | 1 | 0 | 280 pCi/L |
| 2004-08-27 | 490 pCi/L | 1 | 0 | 490 pCi/L |
| 2004-07-14 | 480 pCi/L | 1 | 0 | 480 pCi/L |