The Power of Information

National Drinking Water Database


Rancho California Water District Utilities - Riverside, CA


Serves 103,414 people

Arsenic (total)

Arsenic contaminates drinking water due to mining runoff, erosion of natural deposits, emissions from glass and electronics processing and the use of arsenical compounds as wood preservatives and pesticides.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
107 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
12 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
142 days
Tests ConductedNumber of individual tests done for this contaminant
511 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Arsenic (total)Arsenic contaminates drinking water due to mining runoff, erosion of natural deposits, emissions from glass and electronics processing and the use of arsenical compounds as wood preservatives and pesticides.4.27 ppb
27 ppb
Yes
MCLGA non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.: 0 ppb
Yes
10 ppb
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 Arsenic (total)

Health Based Limits for Arsenic (total)

StandardDescriptionLevel
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.0 ppb
California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.<0.01 ppb
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.0.02 ppb
One in one million (10-6) Cancer RiskThe 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.0.02 ppb
One in ten thousand (10-4) Cancer RiskThe 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.2 ppb
Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.10 ppb
Drinking Water Equivalent LevelA lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.10 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-03-090 ppb110 ppb
2009-03-058.48 ppb503.3 to 23 ppb
2009-03-043.41 ppb830 to 7.3 ppb
2009-03-033.6 ppb103.6 ppb
2009-02-112.5 ppb102.5 ppb
2009-02-045.02 ppb1120 to 19 ppb
2009-01-271.8 ppb630 to 4.6 ppb
2009-01-135.88 ppb603.2 to 9 ppb
2009-01-085.86 ppb520 to 22 ppb
2008-12-232.53 ppb620 to 6.3 ppb
2008-12-055.36 ppb530 to 22 ppb
2008-12-030 ppb110 ppb
2008-11-121.72 ppb640 to 7.3 ppb
2008-11-065.86 ppb520 to 24 ppb
2008-10-280 ppb110 ppb
2008-10-014.45 ppb1150 to 22 ppb
2008-09-250 ppb110 ppb
2008-09-242.12 ppb630 to 6.6 ppb
2008-09-1627 ppb1027 ppb
2008-08-267.48 ppb510 to 26 ppb
2008-08-252.4 ppb530 to 7.6 ppb
2008-08-122.4 ppb102.4 ppb
2008-08-111.8 ppb210 to 3.6 ppb
2008-07-293.14 ppb530 to 12 ppb
2008-07-080 ppb110 ppb
2008-07-074.88 ppb503.1 to 7.1 ppb
2008-06-194.06 ppb530 to 16 ppb
2008-06-115.3 ppb105.3 ppb
2008-06-101.37 ppb320 to 4.1 ppb
2008-06-051.42 ppb540 to 7.1 ppb
2008-06-045.03 ppb830 to 23 ppb
2008-06-030 ppb440 ppb
2008-05-150 ppb110 ppb
2008-05-064.12 ppb530 to 17 ppb
2008-04-152.8 ppb102.8 ppb
2008-04-095.14 ppb520 to 16 ppb
2008-04-080.73 ppb430 to 2.9 ppb
2008-03-113.06 ppb520 to 6.2 ppb
2008-03-040 ppb110 ppb
2008-01-1012 ppb1012 ppb
2008-01-070 ppb110 ppb
2007-12-110 ppb110 ppb
2007-11-144.1 ppb520 to 14 ppb
2007-10-035.97 ppb620 to 17 ppb
2007-09-054.46 ppb530 to 20 ppb
2007-08-140 ppb110 ppb
2007-08-015.06 ppb520 to 20 ppb
2007-07-038.32 ppb610 to 22 ppb
2007-06-275.6 ppb520 to 23 ppb
2007-06-1922 ppb1022 ppb
2007-06-1222 ppb1022 ppb
2007-06-0722 ppb1022 ppb
2007-05-3022 ppb1022 ppb
2007-05-030 ppb110 ppb
2007-05-0210 ppb210 to 20 ppb
2007-03-072.6 ppb102.6 ppb
2007-01-190 ppb110 ppb
2006-12-074.95 ppb203.2 to 6.7 ppb
2006-12-0523 ppb1023 ppb
2006-10-127.1 ppb107.1 ppb
2006-09-070 ppb110 ppb
2006-09-060 ppb110 ppb
2006-08-070 ppb110 ppb
2006-07-120 ppb110 ppb
2006-06-084.75 ppb210 to 9.5 ppb
2006-05-129.1 ppb109.1 ppb
2006-04-196 ppb106 ppb
2006-04-188.2 ppb108.2 ppb
2006-04-134.63 ppb403.3 to 7.1 ppb
2006-04-040 ppb110 ppb
2006-03-140 ppb110 ppb
2006-03-090 ppb110 ppb
2006-03-083.7 ppb103.7 ppb
2006-03-072.9 ppb102.9 ppb
2006-02-143.1 ppb103.1 ppb
2006-01-264.4 ppb104.4 ppb
2006-01-113.4 ppb410 to 7.6 ppb
2006-01-105.6 ppb105.6 ppb
2006-01-064.4 ppb410 to 9.2 ppb
2006-01-054.4 ppb104.4 ppb
2006-01-042.7 ppb202.4 to 3 ppb
2005-12-0920 ppb1020 ppb
2005-12-060 ppb110 ppb
2005-11-033.7 ppb103.7 ppb
2005-10-183.75 ppb202.3 to 5.2 ppb
2005-10-110 ppb110 ppb
2005-10-0511 ppb1011 ppb
2005-08-090 ppb110 ppb
2005-07-140 ppb110 ppb
2005-07-133.67 ppb310 to 6 ppb
2005-07-122.16 ppb1380 to 8 ppb
2005-07-072.76 ppb1260 to 16 ppb
2005-07-062.41 ppb840 to 6.9 ppb
2005-06-233.25 ppb210 to 6.5 ppb
2005-06-226.6 ppb106.6 ppb
2005-06-155.5 ppb304.9 to 6.5 ppb
2005-06-143.24 ppb950 to 12 ppb
2005-06-081.96 ppb1690 to 9.4 ppb
2005-06-0711 ppb303.3 to 24 ppb
2005-06-052.47 ppb320 to 7.4 ppb
2005-05-122.62 ppb950 to 11 ppb
2005-05-051.99 ppb1280 to 8.5 ppb
2005-05-033.92 ppb1550 to 22 ppb
2005-04-260 ppb110 ppb
2005-04-192.45 ppb420 to 6.9 ppb
2005-04-141.88 ppb850 to 8 ppb
2005-04-130.94 ppb540 to 4.7 ppb
2005-04-124.55 ppb403.6 to 5.9 ppb
2005-04-054.56 ppb1450 to 19 ppb
2005-03-230 ppb110 ppb
2005-03-170 ppb220 ppb
2005-03-161.2 ppb320 to 3.6 ppb
2005-03-154.4 ppb303.7 to 5.1 ppb
2005-03-116.06 ppb710 to 19 ppb
2005-03-092.52 ppb520 to 5.7 ppb
2005-03-082.53 ppb420 to 7.3 ppb
2005-03-021.9 ppb1170 to 7.6 ppb
2005-02-283.45 ppb210 to 6.9 ppb
2005-02-160 ppb110 ppb
2005-02-154.55 ppb202.4 to 6.7 ppb
2005-02-140 ppb550 ppb
2005-02-102.9 ppb610 to 6.7 ppb
2005-02-092.63 ppb1160 to 8.6 ppb
2005-02-083.56 ppb750 to 19 ppb
2005-02-020 ppb330 ppb
2005-01-266.6 ppb106.6 ppb
2005-01-240 ppb110 ppb
2005-01-200 ppb110 ppb
2005-01-194.65 ppb204.4 to 4.9 ppb
2005-01-187.73 ppb305.3 to 9 ppb
2005-01-134.21 ppb810 to 12 ppb
2005-01-110.78 ppb430 to 3.1 ppb
2005-01-102.93 ppb420 to 6.3 ppb
2005-01-060.25 ppb11100 to 2.8 ppb
2004-09-092.5 ppb102.5 ppb
2004-08-116.3 ppb106.3 ppb
2004-07-0723 ppb1023 ppb
2004-05-130 ppb220 ppb
2004-05-122.3 ppb102.3 ppb
2004-05-1114 ppb1014 ppb
2004-03-120 ppb110 ppb
2004-01-130 ppb110 ppb