Water Quality Reports

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Glendale Water & Power customers know they can count on excellent water quality and water reliability. Each year, GWP sends a water quality report to every customer in the city. Consistently, these reports show that Glendale water meets and, in many instances, surpasses all federal and state drinking water standards.

Water quality is not taken for granted at Glendale Water & Power. GWP closely monitors drinking Glendale water to maintain its high quality. Each month, GWP conducts about 250 different tests on Glendale water and the results are reported to the State Health Department.

To Request a Hard Copy

If you prefer a hard copy of the CCR to be mailed to you, email us at GWPConservation@glendaleca.gov or call our Customer Service Department at 855-550-4497.

You can view GWP's Water Quality Report in Adobe PDF format below:

Questions?

Email us at GWPWaterQuality@GlendaleCA.gov.

Where Your Water Comes From

Glendale’s water supply comes from a diverse and resilient portfolio of sources, and GWP’s team is always working to keep the supply reliable and to operate the water system efficiently. The total amount of water needed every year depends on you. Typically during warmer years customer demands go up and during cooler years they go down. So, GWP’s Water Facility Operators have to balance the supplies to meet the demands.

Groundwater is pumped from wells in the San Fernando Basin to supply about 25% of Glendale’s water. This supply is limited due to the Upper Los Angeles River Area (ULARA) judgment, and GWP maximizes the amount pumped from the San Fernando Basin by running it through the Glendale Water Treatment Plant (GWTP) to help clean-up the basin as part of an Environmental Protection Agency Superfund clean-up project called the Glendale Operable Unit. The GWTP has been in service for nearly 20 years. The GWTP extracts groundwater that has chemicals in it from the manufacturing industries that used to be in the San Fernando Valley, and cleans it up.

The treatment plant removes chemicals and metals using multiple treatment process including ion-exchange, air-stripping, and adsorption through a granular-activated carbon media. These processes along with disinfection, improves the water quality so that it meets or exceeds all State and Federal drinking water standards. Operation of the GWTP is funded by a group of industries that potentially caused the contamination which allows GWP to keep water rates low by enabling GWP to use Glendale’s water rights in the San Fernando Basin to produce local water and reduce the amount of purchased imported water needed, benefitting today’s residents and customers. Glendale was a pioneer in researching effective methods of removing Chromium VI from groundwater at the GWTP and you can download this study at the link below.

Hexavalent Chromium Removal Research Project

Groundwater is also pumped form the Verdugo Basin. Water pumped from these wells is treated by disinfection and then blended in one of two reservoirs with water from MWD. Due to declining groundwater levels in the basin, pumping is limited. To help get the benefit of water rights in this basin, GWP drilled the Rockhaven Well and is now leasing the well and the associated water rights to the Crescenta Valley Water District, which has a nitrate treatment plant that can treat the water from this well.

The City of Glendale is co-owner of the LA-Glendale Water Reclamation Plant. As co-owner, Glendale is entitled to 50% of the treated water produced by the plant. The demand from Glendale’s recycled water customers currently varies, mainly due to weather, and is between 1,600 and 2,000 ACFT per year, which is between 6% and 7% of the City’s total water demand. GWP has several projects planned to use an additional 400 ACFT per year of recycled water, and offset the amount of potable water needed to meet these demands.

Glendale’s main source of water is the Metropolitan Water District of Southern California (MWD). Glendale was one of the 13 founding Cities of MWD in 1928. As a Member Agency of MWD, Glendale is able to have a reliable supply of water from two different sources. The first source is the Colorado River Aqueduct, which is dependent on precipitation in the mountains and basins that feed the Colorado River. The second source is the State Water Project, which is dependent on precipitation in the Sierra Nevada Mountains in California. MWD has connected both sources into an integrated system to increase resiliency, and MWD has built multiple reservoirs and conveyance systems to move and store water within the region. MWD completed the Diamond Valley Lake in 1999 at a cost of $2 billion and the water stored in this reservoir helped reduce the impact of the Drought of 2015 to the residents of Glendale.

The water supplied by the State Water Project and the Colorado River Aqueduct is naturally desalinated using solar power as the sun warms the ocean and evaporates water into the atmosphere which falls as snow in the Sierra Nevada Mountains and the Rocky Mountains which then melts and flows into the two aqueducts. After collection and transportation, the MWD treats the water that Glendale uses at one of two regional surface water treatment plants, first disinfecting it with Ozone treatment, then coagulation, flocculation, sedimentation and filtration and finally with additional disinfection prior to delivery to Glendale.

So, with long range planning and day-to-day operational knowhow, GWP is always working to maintain an efficient and reliable water supply for the City of Glendale.

Important Information on Water Disinfection

Glendale Water and Power chloramines to disinfect your water and to keep it safe while it travels through the water distribution system. Below are answers to common questions about chloramines.

PFAS Information

Glendale Water & Power has been helping to clean-up the groundwater in the San Fernando Basin for nearly a quarter of a century as part of an EPA Superfund clean-up project called the Glendale Operable Unit. As part of the clean-up process a series of wells extract groundwater then send it to the Glendale Water Treatment Plant for clean-up to stringent drinking water standards. The treatment plant uses multiple technologies to clean-up the groundwater. One of the technologies is Granular Activated Carbon, or GAC for short, and this treatment technology removes PFAS and other contaminants. In 2020, the State Water Resources Control Board, Division of Drinking Water, issued a drinking water permit amendment to the City of Glendale to monitor and remove perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) from the extracted groundwater at the treatment plant. At the discharge from Grandview Pump Station, which is the point of compliance for the drinking water permit and where the water enters the distribution system, PFOA and PFOS are being monitored to ensure compliance with drinking water regulatory requirements. The Glendale Water Treatment Plant continues to be an important and successful project for maintaining and protecting Glendale’s local water supply.

Click here to visit the EPA website and find out more about PFAS, and PFAS in the environment.

Frequently Asked Questions

Why does my water leave a white residue on glass and metal surfaces?

The white, crusty residue sometime left behind when water dries on a surface is a product of water hardness. Hardness is basically an indication of the presence of minerals in water. Minerals are naturally occurring and do not pose a health risk. Mineral deposits, usually calcium, may form in larger quantities in water that is either too hot or too cold; this is why customer frequently see deposits on tea kettles and in ice cubes. A mild vinegar solution is usually sufficient to clean fresh mineral deposits on glass and metal surfaces.

My drinking water is reddish brown. Why?

Reddish-brown water can be caused by rust dislodged from the drinking water pipes in the street, those leading to, or inside, your home, or from your hot water tank. If you are having trouble and your neighbors are not, then the color is likely originating somewhere in your plumbing system. Let your water run until it clears up before using it.

Should I install a home water treatment device?

This is a personal decision. These devices are not needed to make the water meet federal, state, or local standards. In fact, if the devices are not properly maintained, they may cause problems of their own. You may consider a home treatment device if you desire to change the taste of your water.

How is the inside of a pipe cleaned after a water main break?

After the work is done, the inside of the pipes are disinfected with a chlorine solution to kill off germs. In some cases, water is flushed through the main at a high velocity by opening a fire hydrant which also allows the water main to be cleaned.

Why do GWP crews let water run down the street?

One way GWP maintains water quality is by cleaning pipelines using a flushing process to clean out sediment and minimize the potential for stagnant water. This process maintains disinfectant residuals and reduces the chances of bacterial growth in the water distribution system. Pipeline cleaning is an important, routine process and a non-wasteful, beneficial use of water.

My water often looks cloudy when taken from a faucet and then clears up. Why?

The cloudy or milky water is caused by tiny air bubbles. After a while, the bubbles rise to the top and dissipate into the air. The cloudiness occurs more often in the winter when the drinking water is cold. Air in water does not pose a health risk.

Why does my water smell like a rotten egg?

The most common cause of the rotten egg or sewage smell is from the gases released by bacterial growth in drain pipes. When you run your faucets, the water enters the drain pipe and forces these gases out, resulting in the smell. To determine if the smell is coming from the drain or the water, fill a glass with water, take it into another room and smell the water in the glass. If you do not smell the same odor from the water in the glass, then the odor is coming from the drain. Cleaning the drain with a mild bleach solution should resolve the problem.

Why does my water smell like chlorine?

State and Federal regulations require that water utilities, including GWP, maintain a disinfectant residual throughout the distribution system. The purpose is to prevent water-borne illnesses by suppressing the growth of bacteria and other potential contaminants. GWP, like many other utilities, uses chlorine and chloramines to comply with these requirements. You may, at times, experience a chlorine taste or odor.

Why is Fluoride added to my drinking water?

While GWP does not directly add fluoride to its drinking water, it is naturally present in Glendale’s groundwater at very low levels and is added by the Metropolitan Water District to water purchased by GWP at a level considered to be safe by both the Centers for Disease Control and the American Dental Association. The addition of fluoride to drinking water has a proven record of improving dental hygiene in the communities where it is practiced. Click here for more information regarding fluoride.

What is Water Hardness?

Water hardness is one of the most common water quality concerns reported by consumers in the United States. Water that is considered to be “hard” is high in dissolved minerals, specifically calcium and magnesium. As the concentration of the dissolved minerals increase, the water becomes harder.

The two most common units of measurement for hardness are grains per gallon and milligrams per liter. Some appliances, such as dishwashers, have a setting to adjust for the hardness of the water. Usually the hardness setting for these appliances is in grains per gallon.

In grains per gallon, water hardness is classified as follows:

Less than 4 grains per gallon is considered to be soft
4 to 7 grains per gallon is considered to be moderately-hard
7 to 10 grains per gallon is hard
greater than 10 grains per gallon is very hard

Is Hard Water Safe to Drink?

Yes, hard water is safe to drink and to use for cooking and cleaning and is not a health risk. State Water Resources Control Board’s Division of Drinking Water and the US Environmental Protection Agency do not consider hard water a health issue and there are no standards or limits set for hardness. Click here for more information on water hardness.