H2o Inc.
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: 60
- Data available: 2014-2019
- Source: Groundwater
Contaminants Detected
5
EXCEED
EWG HEALTH
GUIDELINES
7 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
Arsenic
Potential Effect: cancer2,275x 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 2,275 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
Cadmium
Potential Effect: harm to the kidney43x EWG'S HEALTH GUIDELINECadmium
more aboutthis contaminant
Cadmium is a toxic metal found in food and drinking water. It has been linked to kidney toxicity, bone damage, cancer, and damage to developing fetuses.
Cadmium 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 0.04 ppb for cadmium 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 harm to internal organs.
Pollution Sources
![industry icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-industry.png)
Industry
![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
![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
Manganese
Potential Effect: harm to the brain and nervous system2.2x EWG'S HEALTH GUIDELINEManganese
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.
Manganese was found at 2.2 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 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
Nitrate
Potential Effect: cancer3.7x 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 3.7 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: cancer9.3x 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 9.3 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
![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.
Chloroform
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.
How your levels compare
EWG Health Guideline
This Utility
National Average
State Average
ppb = parts per billion
Health Risks
The EWG Health Guideline of 0.4 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
Fluoride
more aboutthis contaminant
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems.
How your levels compare
This Utility
Legal Limit
National Average
State Average
ppm = parts per million
Pollution Sources
![water treatment icon](https://static.ewg.org/reports/2017/tap-water/img/pollution-source-treatment-byproducts.png)
Treatment Byproducts
Filtering Options
![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
✕H2o Inc. compliance with legally mandated federal standards:
- From April 2019 to March 2021, H2o Inc. complied with health-based drinking water standards.
- 3 QUARTERSin violation of any federal drinking water standard from April 2019 to March 2021
Information in this section on H2o Inc. 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 | ✔ | ✔ | |
Cadmium | ✔ | ✔ | ✔ |
Manganese | ✔ | ||
Nitrate | ✔ | ✔ | |
Total trihalomethanes (TTHMs) | ✔ | ✔ | |
OTHER CONTAMINANTS DETECTED | |||
Chloroform | ✔ | ✔ | |
Fluoride | ✔ |
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