napa, CA
Total Incidents:
178
Last Incident:
January 01, 2018
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.
Contaminants
TTHM
74
Incidents
Coliform (TCR)
43
Incidents
Total Haloacetic Acids (HAA5)
36
Incidents
Turbidity
17
Incidents
Arsenic
8
Incidents
TTHM
Description
Trihalomethanes occur when naturally-occurring organic and inorganic materials in the water react with the disinfectants, chlorine and chloramine.
Health Effects
Liver, kidney or central nervous system problems; increased risk of cancer
Coliform (TCR)
Description
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.
Health Effects
Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5
Total Haloacetic Acids (HAA5)
Description
Haloacetic acids occur when naturally-occurring organic and inorganic materials in the water react with the disinfectants, chlorine and chloramine.
Health Effects
Increased risk of cancer
Turbidity
Description
Turbidity refers to cloudiness of water. Turbidity has no health effects, but can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea and associated headaches.
Health Effects
Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.
Arsenic
Description
Arsenic is a semi-metal element in the periodic table. It is odorless and tasteless. It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices. Approximately 90 percent of industrial arsenic in the U.S. is currently used as a wood preservative, but arsenic is also used in paints, dyes, metals, drugs, soaps, and semi-conductors. Agricultural applications, mining, and smelting also contribute to arsenic releases in the environment.
Health Effects
Skin damage or problems with circulatory systems, and may have increased risk of getting cancer
All Incidents
| Water System | Type | Measure | Violation | Effects | Begin Date |
|---|---|---|---|---|---|
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2018-01-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-10-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-07-01 |
| DOMAINE CARNEROS | Arsenic | MCL, Average | Maximum Contaminant Level Violation | Skin damage or problems with circulatory systems, and may have increased risk of getting cancer | 2017-04-01 |
| AMERICAN CANYON, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-04-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-04-01 |
| AMERICAN CANYON, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-04-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2017-01-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2017-01-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2017-01-01 |
| CALISTOGA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-10-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-10-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-10-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-10-01 |
| CALISTOGA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-10-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-10-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-10-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-07-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-07-01 |
| ST. HELENA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2016-07-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-07-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-07-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-04-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-04-01 |
| BERRYESSA HIGHLANDS | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-01-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-01-01 |
| BERRYESSA ESTATES (LBRID) | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-01-01 |
| BERRYESSA ESTATES (LBRID) | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-01-01 |
| KATHRYN HALL WINERY | 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 | 2016-01-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2016-01-01 |
| GOOSECROSS CELLARS | 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 | 2016-01-01 |
| FRANK FAMILY VINEYARDS | 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 | 2015-11-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| CAPELL VALLEY ESTATES | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| CAPELL VALLEY ESTATES | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| PEJU PROVINCE | 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 | 2015-10-01 |
| PEJU PROVINCE | 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 | 2015-10-01 |
| CAPELL VALLEY ESTATES | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-10-01 |
| DARIOUSH WINERY | 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 | 2015-08-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-07-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-07-01 |
| ETUDE WINES | 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 | 2015-07-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-07-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-07-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-04-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-04-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-04-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-04-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-01-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-01-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-01-01 |
| LINDA FALLS TERRACE MUTUAL | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2015-01-01 |
| CALISTOGA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-01-01 |
| NAPA, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2015-01-01 |
| MILTON ROAD WATER COMPANY | 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 | 2014-12-01 |
| GROTH VINEYARDS & WINERY | 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 | 2014-10-01 |
| CONN CREEK WINERY | 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 | 2014-10-01 |
| TUCKER ACRES MUTUAL WATER CO. | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2014-07-01 |
| NEWTON VINEYARD | 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 | 2014-07-01 |
| RANCHO LA JOTA | 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 | 2014-07-01 |
| OPUS ONE WINERY | 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 | 2014-06-01 |
| PINE RIDGE WINERY | 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 | 2014-06-01 |
| DOMAINE CHANDON | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2014-05-01 |
| NEWTON VINEYARD | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2014-04-01 |
| NEWTON VINEYARD | 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 | 2014-04-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2014-03-01 |
| DOMINUS ESTATE WINERY | 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 | 2013-10-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2013-09-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2013-08-01 |
| NAPA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2013-07-01 |
| NAPA, CITY OF | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2013-07-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-07-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2013-07-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-07-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-04-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-04-01 |
| AMERICAN CANYON, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-01-01 |
| AMERICAN CANYON, CITY OF | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2013-01-01 |
| ROUND HILL WINERY | 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 | 2013-01-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2012-10-01 |
| BERRYESSA ESTATES (LBRID) | 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 | 2012-09-01 |
| MILTON ROAD WATER COMPANY | 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 | 2012-08-01 |
| MEYERS WATER CO. | 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 | 2012-07-01 |
| BERRYESSA ESTATES (LBRID) | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2012-07-01 |
| BERRYESSA ESTATES (LBRID) | TTHM | MCL, Average | Maximum Contaminant Level Violation | Liver, kidney or central nervous system problems; increased risk of cancer | 2012-07-01 |
| VAILIMA ESTATES MUTUAL WATER | 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 | 2012-03-01 |
| HOWELL MTN SCHOOL | 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 | 2012-02-01 |
| NAPA COUNTY SCHOOLS: POPE VALLEY | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2012-01-01 |
| NAPA COUNTY SCHOOLS: POPE VALLEY | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2012-01-01 |
| MUMM OF NAPA VALLEY | Coliform (TCR) | Notification, State | Other Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-11-01 |
| MUMM OF NAPA VALLEY | Coliform (TCR) | Notification, State | Other Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-11-01 |
| VAILIMA ESTATES MUTUAL WATER | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-11-01 |
| NAPA VALLEY MARINA | Coliform (TCR) | MCL, Acute (TCR) | Maximum Contaminant Level Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-10-01 |
| NVUSD: CARNEROS SCHOOL | 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 | 2011-10-01 |
| SKYLINE PARK | Coliform (TCR) | Notification, State | Other Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-07-01 |
| SKYLINE PARK | Coliform (TCR) | Notification, State | Other Violation | Not a health threat in itself; it is used to indicate whether other potentially harmful bacteria may be present5 | 2011-07-01 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | Total Haloacetic Acids (HAA5) | MCL, Average | Maximum Contaminant Level Violation | Increased risk of cancer | 2011-04-01 |