CONTRA COSTA, CA

Total Incidents:
148
Last Incident:
July 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.

All Incidents (Page 2)

Water System Type Measure Violation Effects Begin Date
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-01-01
MORAGA HEIGHTS 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 2012-12-01
MORAGA HEIGHTS 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
BETHEL ISLAND GOLF COURSE & COUNTRY CLUB 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
BETHEL ISLAND GOLF COURSE & COUNTRY CLUB 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
VALLEY ORCHARD MUTUAL WATER SYSTEM 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
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-10-01
BAY STANDARDS 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
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-10-01
LAZY M MARINA 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 2011-08-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-07-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2011-07-01
BETHEL MARKET 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 2011-07-01
CONCORD MT DIABLO TRAILRIDE ASSOC. 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 2011-05-01
RIVERVIEW WATER ASSOCIATION 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 2011-05-01
MORAGA HEIGHTS 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 2011-01-01
SANDMOUND MUTUAL 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 2010-12-01
RIVERVIEW MOBILE HOMES 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 2010-12-01
SUGAR BARGE MARINA 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 2010-11-01
WAHL FAMILY WATER SYSTEM 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 2010-09-01
NEIGHBORHOOD CHURCH 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 2010-09-01
DOUBLETREE RANCH WATER SYSTEM 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 2010-08-01
MORAGA HEIGHTS 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 2010-08-01
DUTCH SLOUGH WATER WORKS 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 2010-04-01
GOLDEN EAGLE SMALL WATER SYSTEM 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
MARIN FOOD SPECIALTIES 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 2009-10-01
HERTZ WATER SYSTEM 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 2009-09-01
KNIGHTSEN ELEMENTARY SCHOOL Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2009-07-01
KNIGHTSEN ELEMENTARY SCHOOL Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2009-07-01
KNIGHTSEN ELEMENTARY SCHOOL Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2009-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-12-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-12-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-12-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-10-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-10-01
ALOHA CLUB Nitrate MCL, Average Maximum Contaminant Level Violation Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. 2008-09-01
ALOHA CLUB Nitrate MCL, Average Maximum Contaminant Level Violation Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. 2008-09-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2008-01-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2007-10-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2007-01-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2006-10-01
DOUBLETREE RANCH WATER SYSTEM Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2006-07-01
BRENTWOOD Nitrate MCL, Single Sample Maximum Contaminant Level Violation Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. 1991-01-01
BRENTWOOD Nitrate MCL, Single Sample Maximum Contaminant Level Violation Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. 1991-01-01