The Power of Information

National Drinking Water Database


Pomona - City, Water Dept. Utilities - Los Angeles, CA


Serves 156,500 people

Nitrate & nitrite

Nitrate and nitrite enter water from fertilizer runoff, leaching from septic tanks, and erosion of natural deposits.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
19 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)
19 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
53 days
Tests ConductedNumber of individual tests done for this contaminant
75 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Nitrate & nitriteNitrate and nitrite enter water from fertilizer runoff, leaching from septic tanks, and erosion of natural deposits.7.73 ppm
19 ppm
Yes
10 ppm
Yes
10 ppm
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 Nitrate & nitrite

Health Based Limits for Nitrate & nitrite

StandardDescriptionLevel
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 ppm
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.10 ppm
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.10 ppm

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-03-024.7 ppm104.7 ppm
2009-02-112.6 ppm102.6 ppm
2009-01-147.7 ppm107.7 ppm
2009-01-064.7 ppm104.7 ppm
2009-01-054.9 ppm104.9 ppm
2008-12-1712 ppm1012 ppm
2008-10-153.1 ppm103.1 ppm
2008-09-051.15 ppm200.29 to 2 ppm
2008-09-0316 ppm1016 ppm
2008-09-022.8 ppm201.1 to 4.5 ppm
2008-08-139.2 ppm109.2 ppm
2008-08-057.9 ppm502.5 to 15 ppm
2008-07-224.6 ppm104.6 ppm
2008-07-1514 ppm1014 ppm
2008-07-0818 ppm1018 ppm
2008-06-1712 ppm1012 ppm
2008-05-2815 ppm1015 ppm
2008-05-140 ppm110 ppm
2008-04-0712 ppm1012 ppm
2008-04-027.2 ppm202.4 to 12 ppm
2008-03-2619 ppm1019 ppm
2008-03-056.4 ppm106.4 ppm
2008-03-040.44 ppm100.44 ppm
2008-03-034.4 ppm203.7 to 5.1 ppm
2008-02-2610.7 ppm209.4 to 12 ppm
2008-02-0615 ppm2011 to 19 ppm
2008-01-315.4 ppm105.4 ppm
2007-10-090 ppm110 ppm
2007-09-130 ppm220 ppm
2007-09-123.2 ppm103.2 ppm
2007-09-112.85 ppm200.2 to 5.5 ppm
2007-09-058.2 ppm108.2 ppm
2007-05-035.4 ppm105.4 ppm
2007-03-284.7 ppm202.7 to 6.7 ppm
2007-03-274.78 ppm300.13 to 7.7 ppm
2006-06-132.9 ppm102.9 ppm
2006-05-100.19 ppm100.19 ppm
2006-05-0916 ppm1016 ppm
2006-04-1113 ppm1013 ppm
2005-09-2116 ppm1016 ppm
2005-07-1914 ppm1014 ppm
2005-06-1613 ppm2013 ppm
2005-06-083.7 ppm103.7 ppm
2005-05-2614 ppm2012 to 16 ppm
2005-05-043.11 ppm200.31 to 5.9 ppm
2005-04-260.3 ppm100.3 ppm
2005-04-254.77 ppm303.3 to 7.4 ppm
2005-04-198 ppm108 ppm
2005-04-1214 ppm1014 ppm
2005-03-033 ppm103 ppm
2005-03-026.4 ppm106.4 ppm
2005-02-1612.37 ppm308.1 to 15 ppm
2004-05-1315 ppm1015 ppm