Napa, CA

Is Napa Tap Water Safe to Drink?

Last Update11:33 pm, August 30, 2021

The estimated price of bottled water

$1.67 in USD (1.5-liter)

User Submitted Ratings for Napa Tap Water

  • Drinking Water Pollution and Inaccessibility 1% Very Low
  • Water Pollution 37% Low
  • Drinking Water Quality and Accessibility 99% Very High
  • Water Quality 63% High

The above data is comprised of subjective, user submitted opinions about the water quality and pollution in Napa, measured on a scale from 0% (lowest) to 100% (highest).

Can You Drink Tap Water in Napa?

Yes, tap water is drinkable.

Tap Safe includes data from many publicly available sources, including the WHO (World Health Organization), CDC (Center for Disease Control), and user submitted databases, but unfortunately there's not enough data about Napa.

To see user submitted ratings of the water quality for California, see the "User Submitted Ratings" box on this page.

The City of Napa is dedicated to preserving the land encircling the local water source to maintain the quality and purity of the water used for Napa’s drinking water users. In the long term, preserving our watersheds is one of the least expensive and most significant actions they can take to decrease the risk of undesired constituents in their drinking water. Algal growth caused by nutrients is the number one reason for taste and odor affecting your tap water. Nutrients in the watershed are raised artificially by wastewater systems and fertilizers and runoff from agricultural traditions. Every five years, the City of Napa administers Source Water Assessments to assess the quality of the water used as the drinking water supply and monitor activities associated with the particular waterway and surrounding districts to define their contribution to contamination.

Where Does Enterprise Tap Water Come From?

City of Napa consumers benefits from a flexible water supply, including three different sources. Depending on which treatment plant is in operation, the source comes from: 

  1. Barker Slough in the Sacramento Delta via the North Bay Aqueduct. Recreational use, urban and agricultural runoff, grazing animals, herbicide application, and seawater intrusion.
  2. Lake Hennessey completed April 2018: Pacific Union College Wastewater Treatment Plant, vineyards, fires, invasive species, possibly hazardous material spills due to traffic accidents (on Highway 128 near the lake), septic tank systems (in Angwin), and grazing wild animals. 
  3. Lake Milliken completed April 2018: Fires, vineyards, and grazing and wild animals.



City of Napa

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 2019 - March 2019), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Utility details

  • Serves: 172102
  • Data available: 2012-2017
  • Data Source: Surface water
  • Total: 23

Contaminants That Exceed Guidelines

  • Bromate
  • Bromodichloromethane
  • Chloroform
  • Dibromochloromethane
  • Dichloroacetic acid
  • Radon
  • Total trihalomethanes (TTHMs)
  • Trichloroacetic acid

Other Detected Contaminants

  • Bromide
  • Bromochloroacetic acid
  • Bromoform
  • Chlorate
  • Chlorite
  • Chromium (hexavalent)
  • Dibromoacetic acid
  • Haloacetic acids (HAA5)
  • Manganese
  • Molybdenum
  • Monochloroacetic acid
  • Nitrate
  • Strontium
  • Strontium-90
  • Vanadium


Always take extra precautions, the water may be safe to drink when it leaves the sewage treatment plant but it may pick up pollutants during its way to your tap. We advise that you ask locals or hotel staff about the water quality. Also, note that different cities have different water mineral contents.

Sources and Resources

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