Is my drinking water safe?

Yes. YLWD water meets or exceeds 100% of all state and federal drinking water standards.

Why does my water taste or smell different during different times of year?

Like other public water agencies in Orange County, YLWD depends on two sources of water. Approximately 70% of our total domestic water supply is local groundwater pumped from wells.

The remainder is imported water purchased from the Metropolitan Water District of Southern California (MWD). MWD imports water from the Colorado River via the Colorado River Aqueduct and from Northern California via the California Aqueduct, also known as the State Water Project.

Imported water is treated at MWD's Diemer Water Treatment Plant, located on Valley View and Diemer Road in Yorba Linda and disinfected using chloramines, a combination of chlorine and ammonia. YLWD uses chlorine to disinfect well water as it enters the distribution system. Because your water sources vary or may be a blend of these two supplies, you may notice a difference in the taste or hardness (mineral content) of the water at different times of the year. None of these factors affects the quality and safety of your water.

Having multiple sources of water is beneficial for YLWD customers. Local groundwater is both high in quality and lower in cost than imported water, which must travel hundreds of miles through aqueduct systems. Having more than one source also improves the overall reliability of our water supply.

Why does my water sometimes look cloudy?

Our water comes from the Colorado River, Northern California and local wells, with the mix varying throughout the year. The well water that YLWD supplies is pumped from hundreds of feet below the ground. That pumping process can sometimes result in aeration, or the mixing of air with water. Aeration creates small bubbles in the water that are harmless but may give the water a cloudy appearance. This mixing of air into the water is also very common with the Metropolitan Water District aqueducts that typically run very full during the summer months.

Tip: If your water looks cloudy, pour some water into a clear glass and let it sit for a minute. As the air bubbles leave the water, the cloudiness will generally disappear. If the cloudiness does not clear, call YLWD at (714) 701-3000.

Do I need bottled or filtered water for safety?

Absolutely not! Bottled water and tap water are regulated by different agencies. The Safe Drinking Water Act (SDWA) is the main federal law that ensures the quality of your tap water.

Under SDWA, the California Environmental Protection Agency (Cal EPA) sets standards for drinking water quality and mandates that water purveyors provide customers with a printed water quality report each year. Bottled water suppliers are not required to provide such data, but some may do so on request.

The water provided to you by YLWD is clean, pure and ready to drink at a fraction of the cost of bottled water.

Before choosing an alternative to tap water, compare the data contained in the YLWD Annual Water Quality Report with water quality data from the bottled water or filtration device you are considering. The decision to use bottled water or a filtration system should be based on taste or other aesthetic considerations not due to health or safety concerns.

Do we have hard water?

Water hardness refers to the mineral content in the water and is commonly expressed in "grains per gallon" of hardness. Generally water with 13 grains or more is considered "hard." Water imported from the Colorado River and Northern California averages 18 grains of hardness while YLWD's well water averages 20 grains of hardness.

Although the hardness of the water does not affect its safety, the higher mineral content can cause white spots on glasses in the dishwasher. YLWD receives water from the Colorado River, Northern California and local wells. The water supply can change throughout the year. Because our water is blended from a variety of sources, you may notice spotting on glassware. YLWD customers who live on the West side of the District tend to receive more groundwater year-round and may have hard water.

If you are concerned with hard water and spotting, it is best to read the owner's manual for your dishwasher and follow the manufacturer's recommendations regarding settings for hard water. Some other tips that may help reduce spotting include using more cold water instead of hot, varying the brand and type of rinse agent and detergent and adding white vinegar to the rinse cycle of the dishwasher.

What type of water softener should I use?

While YLWD does not recommend the use of water softening or conditioning systems, we realize that some customers do not care for the "hard" (high mineral content) water many areas of Southern California receive. If you opt for a water softener for your home, there are a few things to be aware of.

YLWD discourages the use of self-regenerating water softeners, the kind that requires rock salt, potassium or other material to be added periodically by the homeowner. The reason is simple. Orange County recycles its wastewater and the salty water discharged by self-regenerating water softeners is not removed during the reclamation process at the treatment plant. The more self-regenerating water softeners used in our service area, the saltier our recycled water becomes.

Recycled water is used to irrigate parks, school yards and golf courses, among other things, and the grass and plants cannot tolerate the high salt content.

There is an environmentally friendly option. If you desire soft water in your home, we encourage you to subscribe to a water softener service that picks up and exchanges the cylinder so the salt does not go down the drain. You'll find several water softening services listed in the Yellow Pages or on the internet. We do not make recommendations on softening services.

Additionally, hooking up a water softener only to the hot water lines will save you money.

Does YLWD add fluoride to the water?

Fluoride has been added to United States drinking water supplies since 1945. Of the 50 largest cities in the country, 43 add fluoride to their drinking water. In late 1995, the State of California passed a law (AB 733) requiring the California Department of Public Health to adopt regulations that require the fluoridation of the water of any public water system with at least 10,000 service connections when the state provided funding. While this funding was never made available to YLWD, in December of 2007, the regional wholesale water supplier, Metropolitan Water District, joined a majority of the nation's public water suppliers in adding fluoride to drinking water in order to prevent tooth decay. In line with recommendations from the California Department of Public Health and the U.S. Center for Disease Control and Prevention, MWD adjusted the natural fluoride level in imported treated water from the Colorado River and State Project water to the optimal range for dental health of 0.7 to 1.3 parts per million.

While there is naturally occurring fluoride in our water, YLWD does not add fluoride to its drinking water supplies. The fluoride content in our groundwater averages 0.5 parts per million, while the level in water imported from the Colorado River and Northern California averages 0.8 parts per million.

Since YLWD's water supply is made up of approximately 30% water from MWD and 70% groundwater, our water has fluoride levels in the range of 0.5 to 0.8 parts per million (milligrams per liter) depending on the blend of water at any given time. Because YLWD's wells already contain a level of fluoride close to the recommended amount, YLWD does not add additional fluoride to our water.

If you are concerned about your children's requirement for fluoride, we suggest you provide your dentist or pediatrician with the fluoride content figures above so a supplement can be prescribed if your health care professional feels it is warranted.

Questions about MWD's fluoridation policy may be directed to Edgar Dymally at (213) 217-5709.

Will filters remove fluoride?

Regular filters and boiling will not remove fluoride, but fluoride can be removed using a reverse osmosis system.

How much sodium is in the water?

Sodium is a safe and natural ion found in all water. The average sodium level in MWD imported water is 95 parts per million. The average level in groundwater is 89 parts per million. Neither the state nor federal government has set a maximum contaminant level (MCL) for sodium. Customers who have concerns about sodium intake should discuss these figures with their physician and follow their recommendation.

Why does my water smell like rotten eggs?

Is the smell coming from all taps or just one?

If it's coming from just one tap, the problem is generally the sink drain and not the water. The odor comes from material such as hair or food particles decomposing in the drain area. To get rid of the odor, pour about a half cup of liquid bleach into the drain. To prevent odors from returning, routinely flush drains with a small amount of bleach once a month or so.

If the smell is coming from all sinks, take a glass of water from a sink into another room without water, such as your living room. Is the odor still present? If not, the problem is with the drains. Use the same suggestion outlined above for all affected drains.

Is the problem tap one that is seldom used (such as a guest bathroom)? Or, if the whole house is involved, did you recently return from vacation?

Often when a sink or shower is not used for a period of time, the material in the drain remains odorless until water is first turned on. When water hits the built-up material, odor is generated. Use the same bleach flushing suggestion as above.

Is the odor coming from both hot and cold water?

If it's coming from just the hot water, your water heater may need flushing. Annual flushing of the hot water heater should keep the problem from returning. Hot water heater odors can also result from having the temperature set too low. To prevent bacterial growth, hot water heaters should not be set below 120 degrees Fahrenheit. Care should be taken in homes with young children, elderly or disabled residents to prevent accidental scalding.

If you continue to experience odor problems with your water, please call our Customer Service department at (714) 701-3000. 

Is water treated with chloramines hazardous to some pets?

YLWD uses chlorine in its drinking water to maintain a disinfection residual in the distribution system. Chlorine is safe for all pets. However, import water received from the Metropolitan Water District is treated with chloramine which is also safe for use and drinking but could be toxic to fish. Water that contains chloramines may be treated a number of ways, including commercial products found in pet supply stores. Customers should 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.

What is chromium?

Chromium is an element found in nature. It is commonly used in manufacturing activities such as steel hardening, aerospace manufacturing, making of paint pigments, and electroplating. When chromium is used in industrial processes, it is often converted to chromium 6.

Chromium may be present in water as chromium 3 and chromium 6. Chromium 3 is an essential nutrient at trace concentrations. Chromium 6 can be present in many forms, some of which are carcinogenic when inhaled at high concentrations. Tests conducted on YLWD's water have identified chromium 6 in extremely low concentrations in all our water wells.

Current regulatory standards assure safe levels of total chromium, the combination of chromium 3 and chromium 6—in drinking water to protect against any possible inhalation hazard. In fact, as an added measure of safety, the state has established a very stringent health protection level for chromium in drinking water even before all the necessary health studies have been completed to set a formal regulation.

What is PFOS and PFOA?

Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) are manmade chemicals that have been used in a variety of industrial and commercial products since the 1940s, some of these products include:

  • stain and water repellents on clothing and furniture
  • paper products
  • fire-fighting foams
  • non-stick cookware and coatings
  • food packaging

According to the U.S. Environmental Protection Agency (USEPA) PFOA and PFOS have been found in soil, air and groundwater sites throughout the U.S. and the world. These chemicals are persistent in the environment and do not break down through normal environmental processes.

On May 19, 2016 the USEPA announced that it had lowered the health advisory levels for two chemicals, PFOS and PFOA.  The original health advisory levels set in 2009 were 200 parts per trillion (ppt) for PFOS and 400 ppt for PFOA.  Based on recent peer-reviewed health studies, the USEPA has lowered the health advisory limit to 70 ppt for the combined concentration of PFOS and PFOA in drinking water. 

The Yorba Linda Water District (YLWD) has detections of PFOS and PFOA in its ground water supply, and is serving blended ground water to customers at concentrations that are below the health advisory threshold. YLWD is monitoring for these contaminates on a frequent basis and has developed a blending strategy of using various wells in conjunction with each other to maintain the concentrations for PFOS and PFOA as low as possible.  Additionally, YLWD is pursuing a technical study from expert consultants for possible treatment technologies that can be implemented in the event that concentrations exceed the health advisory level.  YLWD is working with the Orange County Water District (OCWD) and various other agencies to determine the source of contamination in the Orange County ground water aquifer.  

For more information on PFOA and PFOS, including potential health concerns, please visit the US EPA’s website at