The Power of Information

National Drinking Water Database


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


Serves 156,500 people - Test data available: 2004-2009

This drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group (EWG) by the California Department of Public Health. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources to protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes test results for this utility and lists potential health concerns.

 
This Drinking Water System
National Average
Exceed Health GuidelinesTests showing chemicals at concentrations above health guidelines established by federal and state health agencies. These guidelines are typically set at a levels that pose no significant health risk.
24 chemicals
4
Health Standard ExceedencesChemicals detected at concentrations above the legal limit, the Maximum Contaminant Level (MCLs) established by the U.S. EPA. 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.
10 chemicals
0.5
Pollutants FoundThe total number of contaminants detected since 2004, according to data provided by the state water agency.
48 chemicals
8
Tests ConductedThe total number of number of water quality tests conducted by water utilities and recorded in data provided by the state water agency.
34,009 tests
420

Contaminants Exceeding Health Guidelines

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
NitrateNitrate enters drinking water sources from fertilizer runoff, leaching septic tanks, and erosion of natural deposits; it is also emitted by chemical, petrochemical and metal-finishing industries.7.17 ppm
19.43 ppm
Yes
10 ppm
Yes
10 ppm
TrichloroethyleneTrichloroethylene is used to remove grease from fabricated metal parts and in the production of some textiles; this pollutant comes from metal degreasing sites, metal finishing and rubber processing industries.1.87 ppb
11.67 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
5 ppb
TetrachloroethyleneTetrachloroethylene (perc) is a common soil and groundwater contaminant used in dry cleaning and as a solvent in automotive and metalworking factories and other industries.1.36 ppb
14 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
5 ppb
1,1-DichloroethyleneIndustrial chemical pollutant from manufacture of adhesives, synthetic fibers, refrigerants and plastic wraps.1.42 ppb
21 ppb
Yes
7 ppb
Yes
7 ppb
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
AluminumAluminum is a metal released from metal refineries and mining operations.94.36 ppb
1000 ppb
Yes
200 ppb
Yes
200 ppb
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.2.58 ppb
15 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
Chromium (total)Chromium is a metal that pollutes drinking water due to discharge from steel and pulp mills and erosion of natural deposits.9.86 ppb
170 ppb
Yes
100 ppb
Yes
100 ppb
Chromium (hexavalent)Chromium is a metal that pollutes drinking water due to discharge from steel and pulp mills and erosion of natural deposits.12.44 ppb
170 ppb
YesYes
100 ppb
ManganeseManganese is a naturally occurring element released from mineral deposits as well as industrial use.2.35 ppb
93 ppb
Yes
50 ppb
Yes
50 ppb
PerchloratePerchlorate is a synthetic oxygen additive in solid fuel propellant for rockets, missiles, and fireworks, and is primarily used by the military and the space industry; it may occur naturally in certain imported agricultural fertilizers.5.4 ppb
17 ppb
Yes
5 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
n-Nitrosodimethylaminen-Nitrosodimethylamine is a carcinogenic water contaminant released from various industrial processes; it also forms in drinking water as disinfection byproduct of chloramination and from agricultural runoff.0.02 ppb
0.26 ppb
Yes
<0.01 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
Alpha particle activityAlpha particles are a form of radiation released from mining waste pollutants and natural sources.2.42 pCi/L
10.5 pCi/L
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 pCi/L
No
15 pCi/L
Lead (total)Lead is a metal that enters water by corrosion of household plumbing systems, discharge of industrial pollution and erosion of natural deposits.0.46 ppb
4.3 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
No
BromoformBromoform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.0.33 ppb
2.95 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
No
80 ppb
Radium-226Radium-226 is a radioactive element usually found around uranium deposits.0.07 pCi/L
0.47 pCi/L
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 pCi/L
No
5 pCi/L
BromodichloromethaneBromodichloromethane is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.0.64 ppb
7.2 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
No
80 ppb
Radium-228Radium-228 is a radioactive element usually found around uranium deposits.0.08 pCi/L
0.88 pCi/L
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 pCi/L
No
5 pCi/L
DibromochloromethaneDibromochloromethane is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.0.66 ppb
7 ppb
Yes
0.4 ppb
No
80 ppb
Total trihalomethanes (TTHMs)Total trihalomethanes constitute the sum of four disinfection byproducts: chloroform, bromodichloromethane, dibromochloromethane, and bromoform.2.55 ppb
22 ppb
Yes
9.8 ppb
No
80 ppb
ChloroformChloroform is a disinfection byproduct from the trihalomethane (THM) family, and is formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.0.93 ppb
10 ppb
Yes
5.7 ppb
No
80 ppb
1,2-Dibromo-3-chloropropane (DBCP)1,2-Dibromo-3-chloropropane is a persistent pesticide and groundwater contaminant associated with male sterility and severe reproductive toxicity; historically used as a soil fumigant on bananas and pineapples; banned by EPA in early 1980s.<0.01 ppb
<0.01 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
No
0.2 ppb
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.7.2 ppb
7.2 ppb
Yes
0.7 ppb
No
60 ppb
Dichloroacetic acidDichloroacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.2.4 ppb
2.4 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
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.

Other Detected Contaminants

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
Barium (total)Barium is a mineral that enters drinking water through drilling and mining waste runoff, discharges from chemical industries and erosion of natural deposits.53.42 ppb
110 ppb
No
700 ppb
No
2000 ppb
CopperCopper is a naturally occuring metal and drinking water contaminant that enters tap water by corrosion of household plumbing systems and erosion of natural deposits.3.48 ppb
29 ppb
No
300 ppb
No
1000 ppb
Selenium (total)Selenium is a naturally occurring element that contaminates water due to mining or petrolum refining, fly-ash from coal-burning power plants, and irrigation of arid farmland soils high in selenium.1.02 ppb
11 ppb
No
50 ppb
No
50 ppb
Combined Uranium (pCi/L)Uranium is a radioactive element commonly found in most rocks; processed ore is used for power generation and weapons manufacture.1.81 pCi/L
7.3 pCi/L
NoNo
15 pCi/L
Gross beta particle activity (pCi/L)Beta particles are a form of radiation frequently associated with nuclear testing and radioactive mineral deposits.1.59 pCi/L
4.85 pCi/L
NoNo
15 pCi/L
TritiumTritium is a pollutant from commercial nuclear reactors, research reactors and government weapons production plants.160.9 pCi/L
627.67 pCi/L
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Strontium-90Strontium-90 is a radioactive pollutant from nuclear fallout and possibly weapons and power production.0.16 pCi/L
1.2 pCi/L
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
DichlorodifluoromethaneDichlorodifluoromethane (Freon 12) is a chlorofluorocarbon refrigerant and aerosol spray propellant; it was banned under the Montreal Protocol as of 2000 because of its ozone-depleting properties.0.09 ppb
2.25 ppb
No
1000 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
MTBEMTBE (methyl tert-butyl ether) is a fuel additive that had been used as an octane enhancer in unleaded gasoline; it contaminates groundwater due to spillage or leakage at gas stations, and has been banned or scheduled for phaseout in most states.0.44 ppb
12 ppb
No
13 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
ChloromethaneChloromethane is a naturally occuring chemical that forms during combustion of plant material; it may be released from the manufacture of silicone, rubber and pesticides, and also forms as a byproduct of water disinfection.0.03 ppb
2.19 ppb
No
30 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
VanadiumVanadium is a metal used as an alloying addition to iron & steel; it is discharged from ceramic, glass, textile, photography, metallurgy and rubber industries.4.28 ppb
6.6 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
o-Dichlorobenzeneo-Dichlorobenzene (1,2-Dichlorobenzene) is an intermediate for making herbicides; it is discharged as a pollutant from the manufacture of agricultural chemicals.0.15 ppb
8.68 ppb
No
420 ppb
No
600 ppb
trans-1,2-Dichloroethylenetrans-1,2-Dichloroethylene is a synthetic chemical used as a solvent, refrigerant, and in the production of pharmaceuticals; it is released as pollutant from various industrial chemical factories.<0.01 ppb
0.48 ppb
No
100 ppb
No
100 ppb
1,1-Dichloroethane1,1-Dichloroethane is used in industrial chemical synthesis, as a solvent for plastics, paint, varnish, and finish removers and as an insecticide/fumigant.0.01 ppb
1.61 ppb
No
3 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
TolueneToluene is a pollutant from petroleum refineries and a chemical used in plastics manufacturing as well as the pharmaceutical, paint and furniture industries.<0.01 ppb
0.12 ppb
No
150 ppb
No
1000 ppb
BromochloromethaneBromochloromethane is a tap water disinfection byproduct; it is also used as an intermediate in chemical manufacturing and a fire extinguishing agent.<0.01 ppb
0.43 ppb
No
50 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
Silver (total)Silver is an element from natural deposits and mining wastes; it is also associated with the development of photographic and x-ray film and the use of silver in antibacterial consumer products.<0.01 ppb
0.24 ppb
No
100 ppb
No
100 ppb
Antimony (total)Antimony is a metal that enters water from petroleum refinery pollution, fire retardants, ceramics, electronics and solder.0.01 ppb
0.84 ppb
No
5.6 ppb
No
6 ppb
DacthalDacthal (DCPA) is an herbicide used on golf courses, home lawns and gardens, and strawberries, cotton, and soybeans; dacthal and its degradates are among the most commonly detected pesticide residues in drinking water wells.0.01 ppb
0.14 ppb
No
70 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
N-nitrosodi-n-butylamine (ndba)N-nitrosodi-n-butylamine is a synthetic chemical used in research and as an intermediate for production of other chemicals.0.73 ppb
2.2 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Bromodichloroacetic acidBromodichloroacetic acid is a disinfection byproduct that forms when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.2.9 ppb
2.9 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
Dibromoacetic acidDibromoacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.2.7 ppb
2.7 ppb
NoNo
60 ppb
Trichloroacetic acidTrichloroacetic acid is a disinfection byproduct regulated by EPA as one of five haloacetic acids that are formed when chlorine, chloramines or other disinfectants react with organic and inorganic matter in water.2.1 ppb
2.1 ppb
No
20 ppb
No
60 ppb
ChlorateChlorate is a disinfection byproduct (unregulated chlorine dioxide byproduct), an herbicide and a pollutant from explosives.63.33 ppb
63.33 ppb
NoLegal at any levelThis is the Federal Limit. State Limits may be lower.
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.

Contaminants Not Detected - 148 chemicals

1,1,1,2-Tetrachloroethane, 1,1,1-Trichloroethane, 1,1,2,2-Tetrachloroethane, 1,1,2-Trichloroethane, 1,1-Dichloropropene, 1,2,3-Trichlorobenzene, 1,2,3-Trichloropropane, 1,2,4-Trichlorobenzene, 1,2,4-Trimethylbenzene, 1,2-Dichloroethane, 1,2-Dichloropropane, 1,3,5-Trimethylbenzene, 1,3-Dichloropropane, 1,3-Dichloropropene, 2,2-Dichloropropane, 2,3,7,8-TCDD (Dioxin), 2,4,5-TP (Silvex), 2,4-d, 2,4-db, 2-Chloroethylvinyl ether, 3-Hydroxycarbofuran, 4,4-dde, Acetone, Acifluorfen (Blazer), Alachlor (Lasso), Aldicarb, Aldicarb sulfone, Aldicarb sulfoxide, Aldrin, alpha-Lindane, Aroclor 1221, Aroclor 1232, Aroclor 1242, Aroclor 1248, Aroclor 1254, Aroclor 1260, Asbestos, Atrazine, Baygon (Propoxur), Bentazon (Basagran), Benzene, Benzo[a]pyrene, Beryllium (total), beta-Lindane, Bromacil, Bromobenzene, Bromomethane, Butachlor, Cadmium (total), Carbaryl, Carbofuran, Carbon tetrachloride, Chlordane, Chloroethane, Chlorothalonil (Bravo), Chlorpropham, cis-1,2-Dichloroethylene, cis-1,3-Dichloropropene, Cyanide, Dalapon, delta-BHC, Di(2-Ethylhexyl) adipate, Di(2-ethylhexyl) phthalate, Di-n-octylphthalate, Diazinon (Spectracide), Dibenz[a,h]anthracene, Dibromomethane, Dicamba, Dichloromethane (methylene chloride), Dichlorprop, Dieldrin, Dimethoate, Dinoseb, Diphenamide, Diquat, Diuron, Endosulfan I, Endosulfan II, Endosulfan Sulfate, Endothall, Endrin, Endrin Aldehyde, Ethyl-t-butyl ether (ETBE), Ethylbenzene, Ethylene dibromide (EDB), Glyphosate, Heptachlor, Heptachlor epoxide, Hexachlorobenzene (HCB), Hexachlorobutadiene, Hexachlorocyclopentadiene, Isopropyl ether, Isopropylbenzene, Lindane, m- & p- Xylene, m-Dichlorobenzene, m-Xylene, Mercury (total inorganic), Methiocarb, Methomyl, Methoxychlor, Methyl ethyl ketone, Methyl isobutyl ketone, Metolachlor, Metribuzin, Molinate (Ordram), Monobromoacetic acid, Monochloroacetic acid, Monochlorobenzene (Chlorobenzene), n-Butylbenzene, n-Nitroso di-N-Propylamine, n-Nitrosodiphenylamine, N-nitrosopiperidine (npip), N-nitrosopyrrolidine (npyr), n-Propylbenzene, Naphthalene, Nitrite, Nitrobenzene, o-Chlorotoluene, o-Xylene, Oxamyl (Vydate), p,p'-DDT, p-Chlorotoluene, p-Dichlorobenzene, p-Isopropyltoluene, p-Xylene, Pentachlorophenol, Picloram, Prometon, Prometryn, Propachlor, sec-Butylbenzene, Simazine, Styrene, Terbacil, Tert-Amyl-Methyl Ether, Tert-Butyl Alcohol, tert-Butylbenzene, Thallium (total), Thiobencarb (Bolero), Total polychlorinated biphenyls (PCBs), Toxaphene, trans-1,3-Dichloropropene, Trichlorofluoromethane, Trichlorotrifluoroethane, Trifluralin, Vinyl chloride, Xylenes (total)

Pollution Summary

48Total Contaminants Detected (2004 - 2009)

Chlorate, Barium (total), Copper, Selenium (total), Silver (total), Antimony (total), Vanadium, Dacthal, Chloromethane, Dichlorodifluoromethane, MTBE, Bromochloromethane, Trichloroacetic acid, Dibromoacetic acid, o-Dichlorobenzene, 1,1-Dichloroethane, trans-1,2-Dichloroethylene, Toluene, Tritium, Strontium-90, Bromodichloroacetic acid, N-nitrosodi-n-butylamine (ndba), Combined Uranium (pCi/L), Gross beta particle activity (pCi/L), Aluminum, Arsenic (total), Chromium (total), Lead (total), Manganese, Nitrate & nitrite, Nitrate, Chromium (hexavalent), n-Nitrosodimethylamine, Dichloroacetic acid, Total haloacetic acids (HAAs), 1,2-Dibromo-3-chloropropane (DBCP), Chloroform, Bromoform, Bromodichloromethane, Dibromochloromethane, Total trihalomethanes (TTHMs), 1,1-Dichloroethylene, Trichloroethylene, Tetrachloroethylene, Radium-226, Radium-228, Alpha particle activity, Perchlorate

10Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Chlorate, Selenium (total), Dacthal, o-Dichlorobenzene, Arsenic (total), Nitrate & nitrite, Nitrate, n-Nitrosodimethylamine, 1,2-Dibromo-3-chloropropane (DBCP), Perchlorate

10Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Nitrate, Copper, Nitrate & nitrite, Lead (total), Arsenic (total), Tetrachloroethylene, MTBE, Antimony (total), Silver (total), Dacthal

34Industrial Pollutants

Chlorate, Barium (total), Selenium (total), Silver (total), Antimony (total), Vanadium, Chloromethane, Dichlorodifluoromethane, MTBE, Bromochloromethane, 1,1-Dichloroethane, trans-1,2-Dichloroethylene, Toluene, Tritium, Strontium-90, N-nitrosodi-n-butylamine (ndba), Combined Uranium (pCi/L), Gross beta particle activity (pCi/L), Aluminum, Arsenic (total), Chromium (total), Lead (total), Manganese, Nitrate & nitrite, Nitrate, Chromium (hexavalent), n-Nitrosodimethylamine, 1,1-Dichloroethylene, Trichloroethylene, Tetrachloroethylene, Radium-226, Radium-228, Alpha particle activity, Perchlorate

14Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Total trihalomethanes (TTHMs), Total haloacetic acids (HAAs), Chloroform, Bromodichloromethane, Dibromochloromethane, Dichloroacetic acid, Trichloroacetic acid, Bromoform, Dibromoacetic acid, Bromodichloroacetic acid, Chloromethane, n-Nitrosodimethylamine, Chlorate, Bromochloromethane

18Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Nitrate, Copper, Nitrate & nitrite, Barium (total), Lead (total), Arsenic (total), Manganese, Radium-228, Radium-226, Alpha particle activity, Gross beta particle activity (pCi/L), Combined Uranium (pCi/L), Chromium (total), Aluminum, Selenium (total), Chromium (hexavalent), Chloromethane, Silver (total)

15Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Chlorate, Vanadium, Dacthal, Chloromethane, Dichlorodifluoromethane, MTBE, Bromochloromethane, 1,1-Dichloroethane, Tritium, Strontium-90, Bromodichloroacetic acid, N-nitrosodi-n-butylamine (ndba), Lead (total), n-Nitrosodimethylamine, Perchlorate

EPA Violation Summary

No violations were reported for this system since 2004.

Information on violations is drawn directly from EPA's national violations database in the Agency's Safe Drinking Water Information System. Analyses by others have raised questions about the quality of the information in EPA's database. For the purposes of this investigation, EWG is not showing below or including in our analyses, those violations for individual water suppliers that occurred on days for which the total number of violations assigned by EPA to that water supplier was greater than 20. This criteria was based on common characteristics of incorrect violations data as identified by water utilities, from a review of EPA's violations data by several hundred utilities prior to the release of EWG's investigation.