Water quality FAQs

EBMUD takes steps to stem formation of disinfection byproducts, maintain high quality drinking water

Our treatment and distribution systems are regulated by the United States Environmental Protection Agency and the State of California Division of Drinking Water, under the state and federal Safe Drinking Water Acts.

EBMUD drinking water quality remains in full compliance with all state and federal regulations. To ensure continued compliance, the District has been taking action over the last several months to address elevated levels of disinfection byproducts. Learn more at ebmud.com/THMs

If you have questions, concerns or problems regarding water quality issues not answered below or if your call is an emergency, call EBMUD at 1-866-403-2683.
We will respond to all water quality related calls within one business day. You may also refer to the Annual Water Quality Report for more information.

Constantly delivering tap water to 1.4 million people in the Bay Area requires a complex system of treatment plants, pipelines, storage tanks and reservoirs. We are always balancing our water supplies, operations and facilities keep water flowing to you. 

Throughout the year, EBMUD may shift water sources from one reservoir to another or may change where water is treated to manage water supplies, adjust for customer water demands and to accommodate maintenance projects. These operational changes can result in customers noticing changes to the taste and smell of their tap water.

Regardless of reservoir source or operational adjustment, all customers receive high-quality drinking water that meets or surpasses all state and federal regulatory requirements. EBMUD's laboratory tests every day to ensure that water quality meets EPA and state standards.

Water tastes and smells:

  • Chlorinous, bleachy, chemical, or medicinal tastes and smells can be caused by the addition of chloramine to the water by EBMUD, and by the interaction between chloramine and organic material in your plumbing system.
  • Sulfurous, decayed, or sewage-like taste or smell can be a result of bacteria growing in your drain or bacteria growing in your water heater.
  • Musty, moldy, or earthy taste or odor can be caused by certain organisms growing in the EBMUD's source water reservoirs. Commonly, warmer weather can cause algae blooms. Algae are filtered out during water treatment but can leave behind compounds that cause a musty or earthy taste or smell. Sometimes when EBMUD uses alternate water supplies, the different chemical makeup of the water may be noticeable to customers as well. 
  • EBMUD works very hard to avoid having these compounds reach our customers and treats the water from our local Bay Area reservoirs (Upper San Leandro and San Pablo) specifically to avoid this.

To help us investigate taste and smell issues in your tap water, call us at 1-866-403-2683 with the following information:

a. What is the location of the premises where the taste or odor occurred?
b. When did you first notice it?
c. Is the taste or smell in the hot or cold water, or both?
d. How would you describe it?

These answers will help us determine the cause of the taste or smell and will also suggest corrective steps to take. EBMUD Water System Inspectors respond to calls regarding taste and odor within one business day.

Some possible causes of problems with water which appears dirty, has an unusual color, or sediment/particles include:

  • Sediments or pipe materials from breaks in water mains or hydrants. Water mains in the distribution system can fail due to age, corrosion, high pressure surges, or damage by construction work. Hydrants can also be broken off by vehicles.
  • High flows can occur in water mains due to fire fighting, water system tests, or maintenance. Unusual high-flow conditions can stir up sediment or scale from water mains.
  • Construction activities: the customer's service connection from the distribution main to the water meter is sometimes disturbed by construction activities of contractors or other utilities.
  • Aging galvanized plumbing: rust particles or scale from galvanized steel home plumbing can also produce reddish-brown water or rust particles, particularly noticeable when a tap is first turned on.

Since there are many causes of dirty water, EBMUD investigates each complaint carefully. Please be prepared to answer the following questions when reporting this problem at 1-866-403-2683.

  1. What is the location of the premises where the dirty water occurred?
  2. When was the dirty water first detected?
  3. What does the water look like? Does it have color?
  4. Are both the cold and hot water dirty?
  5. Is the water dirty at all faucets?
  6. Are the particles large, small, or colored; does the water look milky or contain air?
  7. Have you had plumbing work done recently on either hot or cold water lines?

The answers to these questions will assist us in finding the cause of the dirty water and may also suggest corrective steps to take. EBMUD Water System Inspectors respond to calls regarding water which appears to be dirty, colored or has foreign particles, within one business day.

Cloudy water could be a result of dissolved air in the water, which is a common and harmless condition. To verify this, place the cloudy water in a glass and observe whether it clears from the bottom up (you may be left with bubbles on the side of the glass and a small surface layer of bubbles). If this occurs then you have dissolved air in the water.

If the cloudy water persists, or if you are noticing unusual tastes or odors, please call 1-866-403-2683, and give us your address and a telephone number so we can have an inspector contact you.

The normal fluoride level in EBMUD drinking water is approximately 1 part per million (1 milligram per liter).

EBMUD uses chloramine in its drinking water to maintain a disinfection residual in the distribution system. Chloramine is safe for all pets except those with gills (fish, tadpoles, etc.). Water that contains chloramine (or chlorine) may be treated a number of ways, including commercial products found in pet supply stores. Just follow the instructions on the package. If you have any questions, consult the manufacturer's web page, because these products contain varying amounts and types of reactive agent.

EBMUD routinely tests water in the mains throughout the service area. Beginning spring 2017, if you are a customer with concerns about lead from your home’s plumbing, EBMUD offers one free lead test annually inside your residence or business.

To request a test:

  • Call EBMUD Customer Service at 866-403-2683 or
  • Send an email by clicking on “Contact Us” at the top of this page. Under “Topic” select “Water Quality.”

If you have a specific concern about a particular contaminant, we recommend you use only qualified laboratories for testing. You can obtain references for qualified laboratories from the State Water Resources Control Board, Environmental Laboratory Accreditation Program at www.waterboards.ca.gov/drinking_water/certlic/labs/