San Diego County Water Authority
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
- San Diego County, California
- Data available: 2014-2019
- Source: Surface water
Contaminants Detected
13
EXCEED
EWG HEALTH
GUIDELINES
29 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.
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Find out which filters earned EWG's recommendation
See the guideContaminants Detected
Arsenic
Potential Effect: cancer700x EWG'S HEALTH GUIDELINEArsenic
more aboutthis contaminant
Arsenic is a potent carcinogen and common contaminant in drinking water. Arsenic causes thousands of cases of cancer each year in the U.S. Click here to read more about arsenic.
Arsenic was found at 700 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.004 ppb for arsenic 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. This health guideline protects against cancer.
Pollution Sources
![agriculture icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-agriculture.png)
Agriculture
![industry icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![naturally occuring icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-naturally-occuring.png)
Naturally Occurring
Filtering Options
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Bromate
Potential Effect: cancer43x EWG'S HEALTH GUIDELINEBromate
more aboutthis contaminant
Bromate is a carcinogenic disinfection byproduct formed when source waters containing bromide are treated with ozonation or sodium hypochlorite. Studies of laboratory animals show that bromate damages DNA and causes cancer in multiple organs. Click here to read more about disinfection byproducts.
Bromate was found at 43 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for bromate 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. This health guideline protects against cancer.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Bromochloroacetic acid
Potential Effect: 93x EWG'S HEALTH GUIDELINEBromochloroacetic acid
more aboutthis contaminant
Bromochloroacetic acid is formed when chlorine or other disinfectants are used to treat drinking water. Bromochloroacetic acid and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
Bromochloroacetic acid was found at 93 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.02 ppb for bromochloroacetic acid was defined in a peer-reviewed scientific study by EWG and represents a on-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Bromodichloromethane
Potential Effect: cancer159x EWG'S HEALTH GUIDELINEBromodichloromethane
more aboutthis contaminant
Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Bromodichloromethane was found at 159 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.06 ppb for bromodichloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Bromoform
Potential Effect: cancer5.8x EWG'S HEALTH GUIDELINEBromoform
more aboutthis contaminant
Bromoform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromoform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Bromoform was found at 5.8 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.5 ppb for bromoform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Chloroform
Potential Effect: cancer22x EWG'S HEALTH GUIDELINEChloroform
more aboutthis contaminant
Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.
Chloroform was found at 22 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Dibromoacetic acid
Potential Effect: 34x EWG'S HEALTH GUIDELINEDibromoacetic acid
more aboutthis contaminant
Dibromoacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dibromoacetic acid was found at 34 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.04 ppb for dibromoacetic acid was defined in a peer-reviewed scientific study by EWG and represents a on-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Dibromochloromethane
Potential Effect: cancer82x EWG'S HEALTH GUIDELINEDibromochloromethane
more aboutthis contaminant
Dibromochloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Dibromochloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dibromochloromethane was found at 82 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for dibromochloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Dichloroacetic acid
Potential Effect: cancer9.3x EWG'S HEALTH GUIDELINEDichloroacetic acid
more aboutthis contaminant
Dichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Dichloroacetic acid was found at 9.3 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.2 ppb for dichloroacetic acid was proposed in 2020 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.a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Haloacetic acids (HAA5)†
Potential Effect: cancer11x EWG'S HEALTH GUIDELINEHaloacetic acids (HAA5)
more aboutthis contaminant
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid.
Haloacetic acids (HAA5) was found at 11 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Total trihalomethanes (TTHMs)†
Potential Effect: cancer152x EWG'S HEALTH GUIDELINETotal trihalomethanes (TTHMs)
more aboutthis contaminant
Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.
Total trihalomethanes (TTHMs) was found at 152 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Trichloroacetic acid
Potential Effect: cancer7x EWG'S HEALTH GUIDELINETrichloroacetic acid
more aboutthis contaminant
Trichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
Trichloroacetic acid was found at 7 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.1 ppb for trichloroacetic acid was proposed in 2020 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.a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![carbon filter icon](https://static.ewg.org/reports/2017/tap-water/img/Carbon-Icon.png)
Activated Carbon
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
Uranium
Potential Effect: cancer4.6x EWG'S HEALTH GUIDELINEUranium
more aboutthis contaminant
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 4.6 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
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](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![naturally occuring icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-naturally-occuring.png)
Naturally Occurring
Filtering Options
![reverse osmosis icon](https://static.ewg.org/reports/2017/tap-water/img/Osmosis-Icon.png)
Reverse Osmosis
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
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.
† HAA5 is a contaminant group that includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. HAA9 is a contaminant group that includes the chemicals in HAA5 and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid and tribromoacetic acid. TTHM is a contaminant group that includes bromodichloromethane, bromoform, chloroform and dibromochloromethane.
Other Contaminants Tested
✕San Diego County Water Authority compliance with legally mandated federal standards:
- From April 2019 to March 2021, San Diego County Water Authority complied with health-based drinking water standards.
- 1 QUARTERin violation of any federal drinking water standard from April 2019 to March 2021
Information in this section on San Diego County Water Authority comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).
LEARN MORE ABOUT THIS UTILITYWater Filters That Can Reduce Contaminant Levels
Contaminant | Activated Carbon | Reverse Osmosis | Ion Exchange |
CONTAMINANTS ABOVE HEALTH GUIDELINES | |||
Arsenic | ✔ | ✔ | |
Bromate | ✔ | ✔ | ✔ |
Bromochloroacetic acid | ✔ | ✔ | |
Bromodichloromethane | ✔ | ✔ | |
Bromoform | ✔ | ✔ | |
Chloroform | ✔ | ✔ | |
Dibromoacetic acid | ✔ | ✔ | |
Dibromochloromethane | ✔ | ✔ | |
Dichloroacetic acid | ✔ | ✔ | |
Haloacetic acids (HAA5) | ✔ | ✔ | |
Total trihalomethanes (TTHMs) | ✔ | ✔ | |
Trichloroacetic acid | ✔ | ✔ | |
Uranium, combined (pCi/L) | ✔ | ✔ | |
OTHER CONTAMINANTS DETECTED | |||
Barium | ✔ | ✔ | |
Bromochloromethane | ✔ | ✔ | |
Caffeine | ✔ | ✔ | |
Chlorate | |||
DCPA mono- and di-acid degradates | ✔ | ✔ | |
Dichloromethane (methylene chloride) | ✔ | ✔ | |
Fluoride | ✔ | ||
Molybdenum | ✔ | ✔ | |
Monobromoacetic acid | ✔ | ✔ | |
Monochloroacetic acid | ✔ | ✔ | |
N-Nitrosodimethylamine (NDMA) | ✔ | ||
Nitrate | ✔ | ✔ | |
Nitrate & nitrite | ✔ | ✔ | |
tert-Butyl alcohol | ✔ | ✔ | |
Tritium | |||
Vanadium | ✔ |
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 MOREFilter Out Contaminants
Check out our recommendations for filters to protect your water against the detected contaminants.
EWG’S WATER FILTER GUIDE