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EWG's Tap Water Database — 2021 UPDATE

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Central Basin Municipal Water District

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the California State Water Resources Control Board, as well as information from the U.S. EPA Enforcement and Compliance History database (ECHO). For the latest quarter assessed by the U.S. EPA (January 2021 - March 2021), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Utility Details

  • Los Angeles County, California
  • Data available: 2014-2019
  • Source: Groundwater

Contaminants Detected

6

EXCEED
EWG HEALTH
GUIDELINES

13 Total Contaminants

  • Legal does not necessarily equal safe. Getting a passing grade from the federal government does not mean the water meets the latest health guidelines.
  • Legal limits for contaminants in tap water have not been updated in almost 20 years.
  • The best way to ensure clean tap water is to keep pollution out of source water in the first place.

Looking for a countertop water filter?

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See the guide

Contaminants Detected

Nitrate

Potential Effect: cancer23x EWG'S HEALTH GUIDELINE
THIS UTILITY3.23 ppm
EWG HEALTH GUIDELINE0.14 ppm
LEGAL LIMIT10 ppm
DETAILS
X

Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.

Nitrate was found at 23 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

3.23 ppm

Legal Limit

10 ppm

National Average

0.935 ppm

State Average

1.9 ppm
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppm = parts per million

Health Risks

The EWG Health Guideline of 0.14 ppm for nitrate was defined by EWG . This health guideline protects against cancer and harm to fetal growth and development.

Pollution Sources

agriculture icon

Agriculture

urban area icon

Runoff & Sprawl

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Nitrate and nitrite

Potential Effect: cancer28x EWG'S HEALTH GUIDELINE
THIS UTILITY3.85 ppm
EWG HEALTH GUIDELINE0.14 ppm
LEGAL LIMIT10 ppm
DETAILS
X

Nitrate and nitrite

more about
this contaminant

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

Nitrate and nitrite was found at 28 times above EWG's Health Guideline.

EWG Health Guideline

0.14 ppm or less

This Utility

3.85 ppm

Legal Limit

10 ppm

National Average

0.888 ppm

State Average

1.76 ppm
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppm = parts per million

Health Risks

The health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.

Pollution Sources

agriculture icon

Agriculture

urban area icon

Runoff & Sprawl

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Perfluorobutane sulfonate (PFBS)

Potential Effect: 4.7x EWG'S HEALTH GUIDELINE
THIS UTILITY4.73 ppt
EWG HEALTH GUIDELINE1 ppt
NO LEGAL LIMIT
DETAILS
X

Perfluorobutane sulfonate (PFBS)

more about
this contaminant

Perfluorobutane sulfonate (PFBS) is a member of a group of perfluorinated chemicals used in many consumer products. PFOS and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.

Perfluorobutane sulfonate (PFBS) was found at 4.7 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

4.73 ppt

National Average

156.3 ppt

State Average

0.297 ppt
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 1 ppt for perfluorobutane sulfonate was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.

Pollution Sources

industry icon

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluorooctane sulfonate (PFOS)

Potential Effect: 21x EWG'S HEALTH GUIDELINE
THIS UTILITY21.1 ppt
EWG HEALTH GUIDELINE1 ppt
PROPOSED LEGAL LIMIT4 ppt
DETAILS
X

Perfluorooctane sulfonate (PFOS)

more about
this contaminant

Perfluorooctane sulfonate (PFOS) is a member of a group of perfluorinated chemicals used in many consumer products. PFOS and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.

Perfluorooctane sulfonate (PFOS) was found at 21 times above EWG's Health Guideline.

EWG Health Guideline

1 ppt or less

This Utility

21.1 ppt

Proposed Legal Limit

4 ppt

National Average

0.908 ppt

State Average

1.63 ppt
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 1 ppt for PFOS was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.

Pollution Sources

industry icon

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Perfluorooctanoic acid (PFOA)

Potential Effect: cancer1,084x EWG'S HEALTH GUIDELINE
THIS UTILITY7.59 ppt
EWG HEALTH GUIDELINE0.007 ppt
PROPOSED LEGAL LIMIT4 ppt
DETAILS
X

Perfluorooctanoic acid (PFOA)

more about
this contaminant

Perfluorooctanoic acid (PFOA) is a member of a group of perfluorinated chemicals used in many consumer products. PFOA and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.

Perfluorooctanoic acid (PFOA) was found at 1,084 times above EWG's Health Guideline.

EWG Health Guideline

0.007 ppt or less

This Utility

7.59 ppt

Proposed Legal Limit

4 ppt

National Average

1.15 ppt

State Average

0.71 ppt
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
ppt = parts per trillion

Health Risks

The EWG Health Guideline of 0.007 ppt for PFOA was proposed by California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

Pollution Sources

industry icon

Industry

urban area icon

Runoff & Sprawl

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Uranium

Potential Effect: cancer3.3x EWG'S HEALTH GUIDELINE
THIS UTILITY1.43 pCi/L
EWG HEALTH GUIDELINE0.43 pCi/L
LEGAL LIMIT20 pCi/L
DETAILS
X

Uranium is a known human carcinogen. The federal legal limit for uranium is set at 30 micrograms per liter (corresponding to parts per billion), but utilities can also report uranium in picocuries per liter (pCi/L), which is a measure of radioactivity in water. EWG translated all uranium results to pCi/L using a conversion factor developed by the EPA. With this conversion approach, the limit of 30 ppb corresponds to 20 pCi/L. Drinking water with this much uranium would cause more than 4.6 cancer cases in a population of 100,000. California set a public health goal for uranium of 0.43 pCi/L.

Uranium was found at 3.3 times above EWG's Health Guideline.

EWG Health Guideline

0.43 pCi/L or less

This Utility

1.43 pCi/L

Legal Limit

20 pCi/L

National Average

1.04 pCi/L

State Average

2.54 pCi/L
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2014-2019.
pCi/L = picocuries per liter

Health Risks

The EWG Health Guideline of 0.43 pCi/L for uranium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. Three most common uranium isotopes are U-234, U-235 and U-238. All isotopes of uranium are radioactive, and the total radioactivity depends on the ratio of isotopes. This health guideline protects against cancer.

Pollution Sources

industry icon

Industry

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Includes chemicals detected in 2017-2019 for which annual utility averages exceeded an EWG-selected health guideline established by a federal or state public health authority; radiological contaminants detected between 2014 and 2019.


Other Contaminants Tested


Chemicals tested for but not detected from 2014 to 2019:

1,1,1,2-Tetrachloroethane , 1,1,1-Trichloroethane , 1,1,2,2-Tetrachloroethane , 1,1,2-Trichloroethane , 1,1-Dichloroethane , 1,1-Dichloroethylene , 1,1-Dichloropropene , 1,2,3-Trichlorobenzene , 1,2,3-Trichloropropane , 1,2,4-Trichlorobenzene , 1,2,4-Trimethylbenzene , 1,2-Dibromo-3-chloropropane (DBCP) , 1,2-Dichloroethane , 1,2-Dichloropropane , 1,3,5-Trimethylbenzene , 1,3-Dichloropropane , 1,3-Dichloropropene , 1,4-Dioxane , 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic aci, 2,2-Dichloropropane , 2,3,7,8-TCDD (Dioxin) , 2,4,5-T , 2,4,5-TP (Silvex) , 2,4-D , 2,4-DB , 2-Chloroethylvinyl ether , 3-Hydroxycarbofuran , 4,4'-dde , 4,8-dioxa-3H-perfluorononanoic acid (ADONA) , 9-chlorohexadecafluoro-3-oxanone-1-sulfonic acid (, Acetone , Acifluorfen (Blazer) , Alachlor (Lasso) , Aldicarb , Aldicarb sulfone , Aldicarb sulfoxide , Aldrin , alpha-Lindane , Aluminum , Antimony , Arsenic , Asbestos , Atrazine , Barium , Baygon (Propoxur) , Bentazon (Basagran) , Benzene , Benzo[a]pyrene , Beryllium , beta-BHC , Bromacil , Bromobenzene , Bromochloromethane , Bromodichloromethane , Bromoform , Bromomethane , Butachlor , Cadmium , Captan , Carbaryl , Carbofuran , Carbon tetrachloride , Carbophenothion , Chlordane , Chloroethane , Chloroform , Chloromethane , Chlorothalonil (Bravo) , Chlorpropham , Chromium (hexavalent) , Chromium (total) , cis-1,2-Dichloroethylene , cis-1,3-Dichloropropene , Cyanazine (Bladex) , Cyanide , Dalapon , DCPA mono- and di-acid degradates , delta-BHC , Di(2-ethylhexyl) adipate , Di(2-ethylhexyl) phthalate , Diazinon (Spectracide) , Dibromochloromethane , Dibromomethane , Dicamba , Dichlorodifluoromethane , Dichloromethane (methylene chloride) , Dichlorprop , Dieldrin , Dimethoate , Dinoseb , Diphenamide , Diquat , Disulfoton , Endosulfan I , Endosulfan II , Endosulfan sulfate , Endothall , Endrin , Endrin aldehyde , EPTC (Eptam) , Ethyl tert-butyl ether , Ethylbenzene , Ethylene dibromide , Glyphosate , Heptachlor , Heptachlor epoxide , Hexachlorobenzene (HCB) , Hexachlorobutadiene , Hexachlorocyclopentadiene , Hexafluoropropylene oxide dimer acid (HFPO-DA) , Isopropyl ether , Isopropylbenzene , Lindane , m-Dichlorobenzene , Manganese , Mercury (inorganic) , Methiocarb , Methomyl , Methoxychlor , Methyl ethyl ketone , Methyl isobutyl ketone , Metolachlor , Metribuzin , Molinate , Monochlorobenzene (chlorobenzene) , MTBE , n-Butylbenzene , N-ethyl perfluorooctane sulfonamido acetic acid (N, N-methyl perfluorooctanesulfonamidoacetic acid , n-Propylbenzene , Naphthalene , Nitrite , o-Chlorotoluene , o-Dichlorobenzene , Oxamyl (Vydate) , p-Chlorotoluene , p-Dichlorobenzene , p-Isopropyltoluene , Para-para DDT , Pentachlorophenol , Perchlorate , Perfluorodecanoic acid (PFDA) , Perfluorododecanoic acid (PFDoA) , Perfluorotetradecanoic acid (PFTA) , Perfluorotridecanoic acid (PFTrDA) , Perfluoroundecanoic acid (PFUnA) , Picloram , Polychlorinated biphenyls (PCBs) , Prometon , Prometryn , Propachlor , Radium, combined (-226 & -228) , sec-Butylbenzene , Selenium , Silver , Simazine , Styrene , Terbacil , tert-Amyl methyl ether , tert-Butylbenzene , Thallium , Thiobencarb , Toluene , Total trihalomethanes (TTHMs) , Toxaphene , trans-1,2-Dichloroethylene , trans-1,3-Dichloropropene , Trichloroethylene , Trichlorofluoromethane , Trichlorotrifluoroethane , Trifluralin , Vinyl chloride , Xylenes (total)

Central Basin Municipal Water District compliance with legally mandated federal standards:

  • From April 2019 to March 2021, Central Basin Municipal Water District complied with health-based drinking water standards.

Information in this section on Central Basin Municipal Water District comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).

LEARN MORE ABOUT THIS UTILITY

Water Filters That Can Reduce Contaminant Levels

ContaminantActivated Carbonactivated carbonReverse Osmosisreverse osmosisIon Exchangeion exchange
CONTAMINANTS ABOVE
HEALTH GUIDELINES
Nitrate
Nitrate & nitrite
Perfluorobutane sulfonate (PFBS)
Perfluorooctane sulfonate (PFOS)
Perfluorooctanoic acid (PFOA)
Uranium, combined (pCi/L)
OTHER CONTAMINANTS
DETECTED
Fluoride
N-Nitrosodimethylamine (NDMA)
Perfluoroheptanoic acid (PFHPA)
Perfluorohexane sulfonate (PFHXS)
Perfluorohexanoic Acid (PFHxA)
Perfluorononanoic acid (PFNA)
Tetrachloroethylene (perchloroethylene)

Take Action

Contact Your Local Official

One of the best ways to push for cleaner water is to hold accountable the elected officials who have a say in water quality – from city hall and the state legislature to Congress all the way to the Oval Office – by asking questions and demanding answers.

LEARN MORE

Filter Out Contaminants

Check out our recommendations for filters to protect your water against the detected contaminants.

EWG’S WATER FILTER GUIDE