Golden State Water Company - Nipomo
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 Luis Obispo County, California
- Serves: 4,904
- Data available: 2014-2019
- Source: Groundwater
Contaminants Detected
8
EXCEED
EWG HEALTH
GUIDELINES
10 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?
Find out which filters earned EWG's recommendation
See the guideContaminants Detected
Bromochloroacetic acid
Potential Effect: 65x 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 65 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: cancer35x 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 35 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: cancer6.9x 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 6.9 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
Dibromoacetic acid
Potential Effect: 43x 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 43 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: cancer39x 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 39 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
Haloacetic acids (HAA5)†
Potential Effect: cancer25x 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 25 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
Nitrate
Potential Effect: cancer25x 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 25 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 icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-agriculture.png)
Agriculture
![urban area icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-runoff-sprawl.png)
Runoff & Sprawl
![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
Total trihalomethanes (TTHMs)†
Potential Effect: cancer64x 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 64 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
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.
† 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.
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 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
![ion exchange icon](https://static.ewg.org/reports/2017/tap-water/img/IonExchange_Icon.png)
Ion Exchange
Monochloroacetic acid
more aboutthis contaminant
Monochloroacetic 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.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 53 ppb for monochloroacetic 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.. This health guideline protects against system toxicity.
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
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 authori.
Other Contaminants Tested
✕Golden State Water Company - Nipomo compliance with legally mandated federal standards:
- From April 2019 to March 2021, Golden State Water Company - Nipomo complied with health-based drinking water standards.
Information in this section on Golden State Water Company - Nipomo 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 | |||
Bromochloroacetic acid | ✔ | ✔ | |
Bromodichloromethane | ✔ | ✔ | |
Bromoform | ✔ | ✔ | |
Dibromoacetic acid | ✔ | ✔ | |
Dibromochloromethane | ✔ | ✔ | |
Haloacetic acids (HAA5) | ✔ | ✔ | |
Nitrate | ✔ | ✔ | |
Total trihalomethanes (TTHMs) | ✔ | ✔ | |
OTHER CONTAMINANTS DETECTED | |||
Manganese | ✔ | ||
Monochloroacetic acid | ✔ | ✔ |
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