City of Oakdale
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
- Oakdale, California
- Serves: 19,250
- Data available: 2014-2019
- Source: Groundwater
Contaminants Detected
9
EXCEED
EWG HEALTH
GUIDELINES
22 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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See the guideContaminants Detected
Arsenic
Potential Effect: cancer249x 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 249 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
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Chromium (hexavalent)
Potential Effect: cancer86x EWG'S HEALTH GUIDELINEChromium (hexavalent)
more aboutthis contaminant
Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).
Chromium (hexavalent) was found at 86 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 chromium (hexavalent) 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
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Nitrate
Potential Effect: cancer20x EWG'S HEALTH GUIDELINENitrate
more aboutthis contaminant
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 20 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
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
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Nitrate and nitrite
Potential Effect: cancer20x EWG'S HEALTH GUIDELINENitrate and nitrite
more aboutthis 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 20 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
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
Runoff & Sprawl
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Radium, combined (-226 & -228)
Potential Effect: cancer12x EWG'S HEALTH GUIDELINERadium, combined (-226 & -228)
more aboutthis contaminant
Radium is a radioactive element that causes bone cancer and other cancers. It can occur naturally in groundwater, and oil and gas extraction activities such as hydraulic fracturing can elevate concentrations.
Radium, combined (-226 & -228) was found at 12 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
pCi/L = picocuries per liter
Health Risks
EWG applied the health guideline of 0.05 pCi/L, defined by the California Office of Environmental Health Hazard Assessment as a public health goal for radium-226, to radium-226 and radium-228 combined. This health guideline protects against cancer.Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Strontium-90
Potential Effect: cancer2.5x EWG'S HEALTH GUIDELINEStrontium-90
more aboutthis contaminant
Strontium is a metal that accumulates in the bones. Radioactive strontium-90 can cause bone cancer and leukemia, and any form of strontium at high doses can harm bone health.
Strontium-90 was found at 2.5 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
pCi/L = picocuries per liter
Health Risks
The EWG Health Guideline of 0.35 pCi/L for strontium-90 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
Industry
Filtering Options
Reverse Osmosis
Ion Exchange
Tetrachloroethylene (perchloroethylene)
Potential Effect: cancer14x EWG'S HEALTH GUIDELINETetrachloroethylene (perchloroethylene)
more aboutthis contaminant
Dry cleaning chemical tetrachloroethylene, or perc, can cause cancer. It pollutes soil and groundwater due to emissions from dry cleaning facilities, and automotive, metalworking and other industries.
Tetrachloroethylene (perchloroethylene) was found at 14 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 0.06 ppb for tetrachloroethylene 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
Industry
Runoff & Sprawl
Filtering Options
Activated Carbon
Reverse Osmosis
Total trihalomethanes (TTHMs)†
Potential Effect: cancer3x 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 3 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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Tritium
Potential Effect: cancer2.3x EWG'S HEALTH GUIDELINETritium
more aboutthis contaminant
Tritium is a radioactive element emitted from nuclear reactors and weapons production plants. Radiation from tritium and other radioactive substances increases the risk of cancer. Click here to read more on radiological contaminants.
Tritium was found at 2.3 times above EWG's Health Guideline.
EWG Health Guideline
This Utility
National Average
State Average
pCi/L = picocuries per liter
Health Risks
The EWG Health Guideline of 400 pCi/L for tritium 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
Industry
Naturally Occurring
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; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 3) program in 2013 to 2015 (and subsequent testing when available), for which annual utility averages exceeded a 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.
1,2,3-Trichloropropane
more aboutthis contaminant
1,2,3-Trichloropropane is a potent carcinogen that contaminates drinking water in agricultural regions where it was historically used as soil fumigant. Click here to read more about carcinogenic VOCs.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.0007 ppb for 1,2,3-trichloropropane 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
Industry
Filtering Options
Activated Carbon
Reverse Osmosis
1-Butanol
more aboutthis contaminant
1-butanol is an industrial petrochemical used in the production of butyl acetate. Exposure to 1-butanol can harm the nervous system, liver and kidneys.
How your levels compare
This Utility
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Filtering Options
Activated Carbon
Reverse Osmosis
Barium is a mineral present in rocks, soil and water. High concentrations of barium in drinking water increase the risk of cardiovascular disease and hypertension.
How your levels compare
EWG Health Guideline
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 700 ppb for barium was defined by EWG as benchmark that protects against harm to the kidneys and the cardiovascular system.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Bromoform
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.
How your levels compare
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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Chlorate
more aboutthis contaminant
Chlorate forms in drinking water as a byproduct of disinfection. Chlorate impairs thyroid function, making chlorate exposure most harmful during pregnancy and childhood.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 210 ppb for chlorate was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against hormone disruption.
Pollution Sources
Agriculture
Industry
Treatment Byproducts
Chromium (total)
more aboutthis contaminant
Chromium is a naturally occurring metal, but industrial uses can elevate its levels in water. One form, hexavalent chromium, causes cancer. Total chromium is not a good indicator of the amount of hexavalent chromium in drinking water.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppb = parts per billion
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Dibromochloromethane
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.
How your levels compare
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
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Haloacetic acids (HAA9)
more aboutthis contaminant
Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of nine haloacetic acids includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid, which are regulated as a group by the federal government (HAA5); and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid, and tribromoacetic acid.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.06 ppb for the group of nine haloacetic acids, or HAA9, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level as . This health guideline protects against cancer.
Pollution Sources
Treatment Byproducts
Filtering Options
Activated Carbon
Reverse Osmosis
Manganese
more aboutthis contaminant
Manganese is a naturally occurring element that is common in food and drinking water. Excessive manganese exposures may impair children's attention, memory and intellectual capacity. Click here to read more about manganese.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 100 ppb for manganese was defined by the state of Minnesota as a health risk limit, the concentration of a contaminant that can be consumed with little or no risk to health. This health guideline protects against harm to the brain and nervous system.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Ion Exchange
Molybdenum
more aboutthis contaminant
Molybdenum is a metal that occurs naturally in soil, minerals and water. People who ingest large amounts can have increased levels of uric acid and gout-like symptoms.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 40 ppb for molybdenum was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against metabolic changes and excess formation of uric acid in the blood.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Strontium
more aboutthis contaminant
Strontium is a metal that accumulates in the bones. Radioactive strontium-90 can cause bone cancer and leukemia, and any form of strontium at high doses can harm bone health.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 1,500 ppb for strontium was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against harm to bones.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Uranium
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.
How your levels compare
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
Naturally Occurring
Filtering Options
Reverse Osmosis
Ion Exchange
Vanadium
more aboutthis contaminant
Vanadium is a metal used in steels and other alloys. People are commonly exposed to vanadium in water and food. Excessive exposure can be toxic during pregnancy and childhood.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 21 ppb for vanadium was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against change in blood chemistry.
Pollution Sources
Industry
Naturally Occurring
Filtering Options
Ion Exchange
Includes chemicals detected in 2017-2019 for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authority; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 3) program in 2013 to 2015 (and subsequent testing when available), for which annual utility averages were lower than an EWG-selected health guideline established by a federal or state public health authority; ; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 4) program in 2017 to 2020 (and subsequent testing when available), for which annual utility averages exceeded a health guideline established by a federal or state public health authori.
Other Contaminants Tested
✕City of Oakdale compliance with legally mandated federal standards:
- From April 2019 to March 2021, City of Oakdale complied with health-based drinking water standards.
Information in this section on City of Oakdale 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 | ✔ | ✔ | |
| Chromium (hexavalent) | ✔ | ✔ | |
| Nitrate | ✔ | ✔ | |
| Nitrate & nitrite | ✔ | ✔ | |
| Radium, combined (-226 & -228) | ✔ | ✔ | |
| Strontium-90 | ✔ | ✔ | |
| Tetrachloroethylene (perchloroethylene) | ✔ | ✔ | |
| Total trihalomethanes (TTHMs) | ✔ | ✔ | |
| Tritium | |||
| OTHER CONTAMINANTS DETECTED | |||
| 1,2,3-Trichloropropane | ✔ | ✔ | |
| 1-butanol | ✔ | ✔ | |
| Barium | ✔ | ✔ | |
| Bromoform | ✔ | ✔ | |
| Chlorate | |||
| Chromium (total) | ✔ | ✔ | |
| Dibromochloromethane | ✔ | ✔ | |
| Haloacetic acids (HAA9) | ✔ | ✔ | |
| Manganese | ✔ | ||
| Molybdenum | ✔ | ✔ | |
| Strontium | ✔ | ✔ | |
| Uranium, combined (pCi/L) | ✔ | ✔ | |
| 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
