Potable (Drinking) Water

2023 Water Quality Report(PDF, 312KB)

2023 Water Quality Report - Spanish(PDF, 841KB)

2023 Water Quality Report Tagalog(PDF, 834KB)

(PDF, 308KB)2022 Water Quality Report(PDF, 308KB)

(PDF, 308KB)2022 Water Quality Report - Spanish(PDF, 285KB)

(PDF, 308KB)2022 Water Quality Report - Tagalog(PDF, 289KB)

(PDF, 308KB)2021 Water Quality Report(PDF, 309KB)

2021 Annual Water Quality Report - Spanish(PDF, 894KB)

(PDF, 308KB)2021 Water Quality Report - Tagalog(PDF, 903KB)

(PDF, 308KB)2020 Water Quality Report(PDF, 305KB)

2020 Annual Water Quality Report - Spanish(PDF, 349KB)

(PDF, 308KB)2020 Water Quality Report - Tagalog(PDF, 408KB)

(PDF, 308KB)2019 Water Quality Report(PDF, 271KB)

2019 Annual Water Quality Report - Spanish(PDF, 274KB)

(PDF, 308KB)2019 Water Quality Report - Tagalog(PDF, 281KB)

To protect drinking water from disease-causing organisms, or pathogens, a disinfectant is added to drinking water. However, disinfection byproducts can form when organic-rich water is disinfected. A major challenge is how to control and limit risks from pathogens and minimize disinfection byproduct formation at the same time. Disinfection byproducts tend to be highest during the warmest time of year or during periods of long detention times in the distribution system or storage tanks. For neighborhoods farthest from treatment and storage facilities, the detention times in the distribution system tend to be longest, allowing more time for these byproducts to form. The particular byproducts at issue are Trihalomethanes (THMs). As a result of regulatory disinfection requirements, the City occasionally exceeds the total Trihalomethane MCL, which requires that a notice be sent to customers in the area where the limit was exceeded.

January 2023 Notice

• INFORMACIÓN IMPORTANTE SOBRE EL AGUA POTABLE
• MAHALAGANG IMPORMASYON TUNGKOL SA INYONG INUMING TUBIG

April 2022 Notice

• INFORMACIÓN IMPORTANTE SOBRE EL AGUA POTABLE
• MAHALAGANG IMPORMASYON TUNGKOL SA INYONG INUMING TUBIG

January 2020 Notice

• INFORMACIÓN IMPORTANTE SOBRE EL AGUA POTABLE
• MAHALAGANG IMPORMASYON TUNGKOL SA INYONG INUMING TUBIG

FAQs

What is a THM, and how is it formed?
A THM, or trihalomethane, is a chemical compound that often occurs in drinking water as a result of the reaction of chlorine treatment for disinfection purposes and natural organic matter present in the water. Often formed in areas of heavy rainfall, especially after a drought or extended period where sediment and debris have not been washed from the earth, THMs are colorless, volatile and readily dissolve in water. The four common THMs are chloroform, dibromochloromethane, dichlorobromomethane, and bromoform. A new water quality regulation (DBPR-II, or Stage II of the Disinfection Byproduct Rule) requires our water to comply with a Total THM maximum contaminant level of 80 ug/l, based on a running annual average at each monitoring location. 

I’ve never heard of disinfection byproducts before, so why am I hearing about this now?
Technological advances in laboratory analytical methods allow us to detect and report constituents we did not know existed as recently as the 1970s. Federal and State drinking water regulations continue to become more stringent. The requirement to notify you directly is similar to the Prop 65 state requirement to post ‘this building contains chemicals dangerous to your health’ signs at convenience stores or other businesses. All efforts are to protect public health.

Discolored water (ranging from light yellow to dark brown) is typically caused by a disturbance of pipeline sediments — including naturally occurring particles and minerals — in the water main. Any of the following circumstances may have caused sediment to be disturbed:

• A nearby water hydrant may have been knocked over due to a vehicle collision or may be in use to fight a fire.
• There may be some pipeline repair work (or construction activity, including emergencies such as main breaks) in the area and some valves may have been closed for this work. Your service connection from the main to the meter is sometimes disturbed by construction activities of contractors or other utilities.
• Changing direction of water flow that occurs when the City switches its water source between American Canyon’s Water Treatment Plant and our supplemental sources from Vallejo Water and/or Napa Water. 
• Aging plumbing — Buildup on galvanized steel home plumbing can produce particles or reddish-brown water, particularly noticeable when the tap is first turned on. The buildup can also create problems of insufficient flow within the home. 
• Issues with your hot water heater, including a defective dip tube or need for maintenance, are also a common source of particles in home plumbing systems.

Despite its appearance, discolored water does not indicate that the water is unsafe or that the integrity of the water main is compromised. A disinfectant residual is maintained at all times to ensure that the water is safe for household use, including cooking and drinking. For aesthetic reasons, you should avoid doing laundry until the water clears up. If you have done laundry and experience issues, please call (707) 647-4550 and our team can provide a product to help remove any stains from your laundry.

If you notice discolored water in your home or business, run water at the hose bibs outside for several minutes and then run cold water inside for at least 5 minutes until the water is clear.  

Reporting a Problem with your Drinking Water  

Before reporting a problem, please note whether your concern is with the water’s color, taste, odor, or something other, and be prepared to answer the following questions:  

• Is the problem in the hot water, cold water, or both?  
• Is the problem observed at all faucets?  
• Do neighbors see a similar problem?  
• Is there construction activity nearby?
• Have you run water at the hose bibs outside for several minutes and then run cold water inside for at least 5 minutes and the water is still not clear?  

Call (707) 647-4364 or (707) 995-8674 after-hours.  

Are personal home filters effective?

Although City water is clean and safe to drink, we understand that many customers choose to use In-home filters.  If you do so, please consider these tips to ensure your water remains safe:

All filters require maintenance. Typically it’s as simple as removing and replacing the filter cartridge. Brita filters that sit in your refrigerator remove the residual chlorine that is in the water.

Be aware that when the chlorine has been removed, just like food in your refrigerator, bacteria and other organisms can grow in the water. Be sure to thoroughly clean your filter and container consistently.

Some home water treatment units are also available to reduce total THMs, or volatile organic compounds, from drinking water. To learn more about available home water treatment units, you may call the California Water Resources Control Board, Division of Drinking Water, at 916-323-0372 or visit this website.

Should I drink bottled water instead?

Bottled water is not regulated to the same level that tap water in California is regulated, but producers spend high dollars on advertising. The cost of bottled water ($1 per 12 oz) is more than 250 times higher than the water that is delivered to your tap at less than a penny per gallon (0.764 cents/gallon) or $0.0007 per 12oz). Bottled water is reasonably expected to contain at least small amounts of some contaminants. If bottled water is bottled in a different state, it may not meet the standards set by the State of California that are more stringent than USEPA requirements for some constituents. More information about contaminants and potential health effects can be obtained by calling the USEPA’s Safe Drinking Water Hotline at (800) 426-4791.

Why do we need to add chlorine to the water?

Chlorine in drinking water has prevented the spread of waterborne diseases and pathogens such as cholera, typhoid fever, dysentery, and hepatitis A. At the turn of the 20th century, typhoid fever alone killed 1 person per 3,500. Drinking water chlorination and filtration have helped to virtually eliminate these diseases in the U.S. and other developed countries.