The Power of Information

National Drinking Water Database


City of Napa Utilities - Napa, CA


Serves 70,000 people

Total haloacetic acids (HAAs)

Total haloacetic acids refers to the sum of the concentrations of five related disinfection byproducts in a water sample: dichloroacetic acid, trichloroacetic acid, monochloroacetic acid, monobromoacetic acid and dibromoacetic acid.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
55 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)
0 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
55 days
Tests ConductedNumber of individual tests done for this contaminant
466 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Total haloacetic acids (HAAs)Total haloacetic acids refers to the sum of the concentrations of five related disinfection byproducts in a water sample: dichloroacetic acid, trichloroacetic acid, monochloroacetic acid, monobromoacetic acid and dibromoacetic acid.21.76 ppb
53.8 ppb
Yes
0.7 ppb
No
60 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 Total haloacetic acids (HAAs)

Health Based Limits for Total haloacetic acids (HAAs)

StandardDescriptionLevel
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.0.7 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.60 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.70 ppb
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.70 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.450 ppb
Children's health-based limit for 1-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for up to one day of exposure. The One-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.5200 ppb
Children's health-based limit for 10-day exposureConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic effects for up to ten days of exposure. The Ten-Day health-based limit (or Health Advisory, HA) is typically set to protect a 10-kg child consuming 1 liter of water per day. Source: U.S. Environmental Protection Agency.5200 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2009-03-1718.68 ppb4013.6 to 25 ppb
2009-03-0416.7 ppb1016.7 ppb
2009-02-0423.6 ppb2110 to 38.9 ppb
2009-01-0721.36 ppb508.1 to 34.3 ppb
2008-12-0321.89 ppb2101.4 to 33.2 ppb
2008-11-0523.14 ppb10012.1 to 33 ppb
2008-10-0122.66 ppb3103.8 to 37.5 ppb
2008-09-0322.61 ppb1507.3 to 34.9 ppb
2008-08-0623.75 ppb3102.7 to 46.2 ppb
2008-07-1614.5 ppb1014.5 ppb
2008-06-0421.53 ppb2610 to 42.2 ppb
2008-05-0723.18 ppb808.1 to 35.2 ppb
2008-04-0225.52 ppb2010 to 39.3 ppb
2008-03-0537.35 ppb4026 to 55.8 ppb
2008-02-0653.8 ppb4041.9 to 61.9 ppb
2008-01-0924.78 ppb5012.8 to 34.9 ppb
2007-12-0517.32 ppb6014.3 to 20.2 ppb
2007-11-0712.16 ppb8010.9 to 13.6 ppb
2007-10-0320.56 ppb12014 to 26.3 ppb
2007-09-0519.1 ppb1208 to 27.8 ppb
2007-08-0122.48 ppb12013.7 to 32.4 ppb
2007-07-1621.02 ppb1505.2 to 33.4 ppb
2007-06-0619.27 ppb1004.7 to 31.5 ppb
2007-05-0230.25 ppb8023.4 to 40.5 ppb
2007-04-0424.1 ppb4019.9 to 30 ppb
2007-03-0720.66 ppb506 to 31.2 ppb
2007-02-0725.25 ppb4019.8 to 32.8 ppb
2007-01-0318.33 ppb4010.9 to 27.9 ppb
2006-12-0618.03 ppb4014 to 27.7 ppb
2006-11-0821.48 ppb4015 to 29 ppb
2006-10-0427.91 ppb8016.6 to 35.7 ppb
2006-09-0627.23 ppb6022 to 30.8 ppb
2006-08-0225.56 ppb8015.8 to 29.1 ppb
2006-07-0523.64 ppb1010 to 35.6 ppb
2006-06-0729.16 ppb8020.9 to 39.6 ppb
2006-05-0340.23 ppb4024.6 to 54.1 ppb
2006-03-0117.68 ppb4011.4 to 25.1 ppb
2005-12-0718.53 ppb4011.5 to 24.6 ppb
2005-11-0920.9 ppb4011 to 29.5 ppb
2005-10-0524.7 ppb1203.1 to 37.1 ppb
2005-07-208 ppb108 ppb
2005-07-1317 ppb1017 ppb
2005-06-0117.13 ppb809 to 34 ppb
2005-05-0414.25 ppb407 to 20 ppb
2005-04-0612 ppb402 to 18 ppb
2005-03-025.25 ppb404 to 7 ppb
2005-02-0232 ppb4013 to 45 ppb
2004-12-087 ppb402 to 11 ppb
2004-11-1014 ppb404 to 22 ppb
2004-10-069.38 ppb820 to 18 ppb
2004-09-0114.08 ppb1210 to 24 ppb
2004-08-0221.75 ppb1203 to 38 ppb
2004-07-1422.83 ppb12013 to 33 ppb
2004-06-0229 ppb1029 ppb
2004-04-0732.5 ppb4021 to 45 ppb