Note: Just because the latest incident is in 2017 or 2018 doesn't mean your water is free of contaminants! There is a considerable lag between when data is collected and when it is published by the EPA.
Coliforms are bacteria that are naturally present in the environment and used as an indicator that other, potentially harmful, bacteria may be present. Coliforms found in more samples than allowed is a warning of potential problems.
Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5
Trihalomethanes occur when naturally-occurring organic and inorganic materials in the water react with the disinfectants, chlorine and chloramine.
Liver, kidney or central nervous system problems; increased risk of cancer
| Water System | Type | Measure | Violation | Effects | Begin Date |
|---|---|---|---|---|---|
| SANTA MARGARITA WATER DISTRICT-NICHOLS I | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-07-01 |
| SANTA MARGARITA WATER DISTRICT-NICHOLS I | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-07-01 |
| MIDWAY CITY MUTUAL WC | Coliform (TCR) | MCL, Monthly (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2009-11-01 |
| MIDWAY CITY MUTUAL WC | Coliform (TCR) | MCL, Monthly (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2009-11-01 |
| RANCHO MISSION VIEJO | Coliform (TCR) | MCL, Monthly (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2009-08-01 |
