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.

Contaminants

All Incidents

Water System Type Measure Violation Effects Begin Date
NEIGHBORHOOD CHURCH 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. 2018-07-01
NEIGHBORHOOD CHURCH 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. 2018-07-01
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 2018-04-01
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 2018-04-01
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 2018-01-01
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 2018-01-01
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 2017-10-01
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 2017-10-01
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 2017-07-01
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 2017-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-07-01
LONE TREE MEDICAL & DENTAL 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. 2017-05-01
LONE TREE MEDICAL & DENTAL 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. 2017-05-01
LONE TREE MEDICAL & DENTAL 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. 2017-05-01
LONE TREE MEDICAL & DENTAL 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. 2017-05-01
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 2017-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-04-01
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 2017-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-04-01
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 2017-01-01
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 2017-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2017-01-01
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 2016-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-10-01
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 2016-10-01
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 2016-10-01
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 2016-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-10-01
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 2016-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-07-01
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 2016-07-01
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 2016-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-04-01
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 2016-04-01
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 2016-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-04-01
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 2016-03-01
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 2016-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2016-01-01
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 2016-01-01
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 2016-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-10-01
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 2015-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-10-01
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 2015-10-01
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 2015-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-07-01
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 2015-07-01
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 2015-07-01
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 2015-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-04-01
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 2015-04-01
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 2015-04-01
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 2015-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2015-01-01
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 2015-01-01
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 2015-01-01
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 2015-01-01
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 2014-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-10-01
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 2014-10-01
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 2014-10-01
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 2014-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-07-01
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 2014-07-01
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 2014-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-04-01
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 2014-04-01
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 2014-04-01
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 2014-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-04-01
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 2014-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2014-01-01
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 2014-01-01
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 2014-01-01
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 2014-01-01
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 2013-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-10-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-07-01
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 2013-07-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-07-01
ANGLERS SUBDIVISION 4 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 2013-05-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-04-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-04-01
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 2013-04-01
BETHEL ISLAND MUTUAL 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 2013-03-01
BETHEL ISLAND MUTUAL 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 2013-03-01
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 2013-01-01
BEACON WEST Arsenic MCL, Average Maximum Contaminant Level Violation Skin damage or problems with circulatory systems, and may have increased risk of getting cancer 2013-01-01