LEARN ABOUT TAP WATER
Where Does My Tap Water Come From?
Use the Path to Tap tool to find out more about your tap water and how it makes its way to your home.
Ventura County Water Supply
The water supply in Ventura County comes from three main sources:
- The State Water Project
- Other local surface water
67% of the water sources is groundwater, which is pumped by individual well owners and by public and private water purveyors within Ventura County.
The source of tap (or drinking) water in our community is a blend of imported State Water and local groundwater treated to meet state and federal drinking water quality standards.
*Percentages fluctuate based on climate conditions Source: Project Changes in Ventura County Climate, Western Regional Climate Center, Desert Research Institute, 2019
Greater Los Angeles County Water Supply
The water supply for the Greater Los Angeles County IRWM comes from three main sources:
- Imported water (including the State Water Project, Colorado River Aqueduct, and Los Angeles Aqueduct)
- Local surface water and recycled water
*Percentages fluctuate based on climate conditions Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014
Upper Santa Clara River Watershed Water Supply
The water supply for the USCR IRWM comes from three main sources:
- California State Water Project
- Water recycling
The State Water Project is sourced from snow pack and rain from the Sierra Nevada range, flows to the Sacramento-San Joaquin Delta, then through the State Water Project Aqueduct to supply water to Los Angeles County. Water recycling allows for municipal wastewater to be treated and re-utilized. Groundwater is the water stored beneath the Earth’s surface. Wells are used to pump the groundwater into our water supply system.
Source: Greater Los Angeles County Integrated Regional Water Management Plan, 2014
About Tap Water Quality
How Clean Is My Drinking Water?
Water quality testing ensures that our drinking water is safe and meets federal and state drinking water standards. The US Environmental Protection Agency establishes federal standards that determine the maximum concentration allowable for specific contaminants in tap water. In California, the State Water Resources Control Board Division of Drinking Water is responsible for regulating drinking water. While tests are important for identifying potential health issues, the presence of some contaminants does not necessarily indicate the water is unsafe to drink for all populations.
How Can Contaminants Get into My Tap Water?
Water service providers are responsible for providing safe drinking water to water meters, and property owners/landlords are responsible for maintaining infrastructure from the meter to tap. In some cases, domestic water quality issues result from infrastructure that is the responsibility of the owner/landlord to maintain.
How often is my water tested and reported?
The State Water Resources Control Board Division of Drinking Water (DDW) requires community water systems to publish and make available an annual Consumer Confidence Report. Water agencies collect water samples from designated sampling points or wells quarterly, and report results in the annual report.
What is my water tested for?
The EPA has set maximum contaminant levels (MCLs) for more than 90 contaminants, and maintains a list of unregulated contaminants that may require thresholds in the future.
Types of Regulated Contaminants:
- Microorganisms such as viruses, bacteria.
- Inorganic chemicals such as lead, arsenic, nitrate, copper, and chromium.
- Radiological contaminants from natural radioactivity or human activity such as uranium and radon.
- Pesticides such as 1,2-Dibromo-3-chloropropane (DBCP), 1,2-Dibromoethane (EDB), and
- Learn more at EPA National Primary Drinking Water Regulations.
What is an exceedance?
An exceedance occurs when a concentration of a contaminant is above the established safe threshold and could potentially cause a threat to human health. When this occurs, agencies are responsible for sending an unsafe water notice to all customers and instructions on how to proceed when using tap water.
Are Property Owners Responsible for Water Quality?
Water service providers are responsible for providing safe water to water meters, and property owners/landlords are responsible for maintaining water infrastructure from the meter to tap. In some cases, domestic water quality issues result from infrastructure that is the responsibility of the owner/landlord to maintain.
How Much Water Does One Person Drink?
How Much Water Do We Use At Home?
The average residential water use in California (2016) is 85 Gallons per person per day.
Estimated residential water use is calculated based on information provided in the following sources: 1.“How We Use Water.” EPA, Environmental Protection Agency, 5 Feb. 2018, www.epa.gov/watersense/how-we-use-water. 2. “Residential Water Use Trends and Implications for Conservation Policy.” Residential Water Use Trends and Implications for Conservation Policy, Legislative Analyst’s Office, 8 Mar. 2017, https://lao.ca.gov/Publications/Report/3611.