Water Quality FAQs

El Toro Water District’s highest priority is protecting the safety and reliability of your drinking water. ETWD’s water comes from high-quality treated surface water supplied by the Metropolitan Water District of Southern California and the Irvine Ranch Water District’s Baker Water Treatment Plant. These facilities use multiple treatment steps and continuous monitoring to meet strict state and federal standards.

Within our service area, ETWD’s state-certified water quality laboratory and team of certified operators routinely collect samples from about 70 locations and perform roughly 12,000 water-quality tests each year. Our laboratory is accredited through California’s Environmental Laboratory Accreditation Program (ELAP).

Results are summarized each year in ETWD’s Annual Water Quality Report (Consumer Confidence Report), which shows that your water meets or exceeds all standards set by the U.S. Environmental Protection Agency (EPA) and the State Water Resources Control Board, Division of Drinking Water. The reports can be found here.

If you have questions about your water quality, you can contact ETWD Customer Service at (949) 837-0660.

A Public Health Goal (PHG) is a health-based goal for a contaminant in drinking water. In California, PHGs are developed by the Office of Environmental Health Hazard Assessment (OEHHA).

A PHG is:

• The level of a contaminant in drinking water that is estimated to pose no significant health risk to people who drink that water every day over a 70-year lifetime.
• Not a regulatory limit and not directly enforceable. Instead, PHGs are used as health-protective targets when the State sets enforceable standards called Maximum Contaminant Levels (MCLs).

It is important to note that PHGs do not consider whether the level is technologically or economically feasible or even measurable. The role of the PHG is to be utilized to ensure that MCLs are set "as close as possible" to the corresponding PHG with the primary emphasis on the protection of public health but also considering technological and economic feasibility. 

Drinking water quality is regulated at both the federal and state levels.

• Federal level – U.S. Environmental Protection Agency (EPA)
  Under the Safe Drinking Water Act, the EPA sets national drinking water regulations, including enforceable Maximum Contaminant Levels (MCLs) for many substances such as microorganisms, disinfectants, disinfection by-products, inorganic chemicals, organic chemicals and radionuclides.
• State level – California State Water Resources Control Board (SWRCB), Division of Drinking Water (DDW)
  California has “primacy,” meaning the State implements and enforces drinking water regulations that must be at least as protective as federal standards. The SWRCB/DDW adopts state MCLs, issues operating permits, and oversees monitoring, reporting and compliance for public water systems like ETWD.

ETWD is required to:

• Monitor for regulated contaminants on specific schedules.
• Report results to state regulators.
• Notify customers and publish an annual Consumer Confidence Report summarizing water-quality results and any required health information.

Trihalomethanes and haloacetic acids are by-products of the disinfection process. Water is disinfected to protect against a wide variety of disease-causing organisms such as cholera, hepatitis and dysentery.  Disinfectants react with small amounts of naturally occurring matter and produce trace levels of these by-products. The California Office of Environmental Health Hazard Assessment (OEHHA) is responsible for developing Public Health Goals (PHGs) and they state, "The use of chemical disinfectants in water treatment usually results in the formation of chemical by-products. However, the risks to health from these byproducts are extremely small in comparison with the risks associated with inadequate disinfection, and it is important that the disinfection efficacy not be compromised in attempting to control such by-products.”¹ The Centers for Disease Control website provides further information on disinfection byproducts. 

ETWD and its suppliers carefully control disinfection and routinely test for THMs and HAAs to ensure levels remain within state and federal standards. These results are reported in the Annual Water Quality Report.

1  https://oehha.ca.gov/sites/default/files/media/downloads/crnr/haaphg013120.pdf

If you would like to test the water at your home or business, contact an independent laboratory accredited through the California Environmental Laboratory Accreditation Program (ELAP). The State maintains an online tool located here where you can search for accredited labs by location and test type.

ETWD’s own water quality laboratory focuses on regulatory monitoring within the public water system and cannot perform private, customer-requested testing.  If you need help deciding what to test for, ETWD staff can help explain your Water Quality Report and direct you to appropriate resources.

Like most of Southern California, ETWD’s drinking water is generally considered hard.

ETWD imports water from the Colorado River as one of its sources. As this water travels through rock formations, it naturally picks up calcium and magnesium, which cause hardness.

Hard water is safe to drink and is considered an aesthetic (taste and household maintenance) issue, not a health concern, by both the U.S. EPA and the State Water Resources Control Board.

The white, chalky film you may notice on dishes, faucets, shower doors and glassware is typically mineral scale left behind when hard water droplets dry.

• It is mainly composed of naturally occurring minerals such as calcium and magnesium that are present in hard water.
• These minerals do not pose a health risk at the levels found in ETWD’s drinking water, but they can be a nuisance around the home and can affect the performance of some appliances over time.

Ways to prevent hard water residue include:

• Wiping down glass and fixtures before droplets dry.
• Using commercial products designed to remove mineral deposits (always follow manufacturer instructions).
• Adjusting dishwasher settings or using detergents formulated for hard water, as recommended in your appliance manuals.

Occasional cloudy or milky-looking water is usually caused by tiny air bubbles in the water, not by a water-quality problem.

• Cold water (especially in cooler months) can hold more dissolved air. When it warms up in your indoor plumbing, that air can come out of solution as tiny bubbles, making the water appear cloudy or white for a short time.
• Air can also enter pipes during construction or maintenance activities and create the same effect.

A simple test:

1. Fill a clear glass or jar with tap water.
2. Set it on the counter and watch for a minute or two.

If the cloudiness clears from the bottom up as the bubbles rise and escape, the cause is air, and the water is safe to drink.

If the water does not clear, or if you see discoloration or particles that don’t settle, contact ETWD Customer Service so we can investigate.

Many times, the odor people notice when using the tap actually comes from the sink drain, not the water itself.

• Over time, food particles, soap and other organic material can collect in the P-trap (the U-shaped section under the sink). Bacteria can break down this material and create unpleasant smells that rise up when you run the water.

If you smell an odor, try this simple test:

1. Fill a clean glass with cold tap water.
2. Step away from the sink—into another room or outside—and then smell the water.

• If the odor is no longer noticeable, it is likely coming from the drain or plumbing, not the water. Cleaning the drain or using a suitable drain cleaner usually solves the problem.
• If you still notice a persistent odor in the glass itself (such as a strong “musty,” “earthy,” or “chemical” smell), contact ETWD so staff can help determine the cause.

ETWD’s water is disinfected primarily with chloramines (a combination of chlorine and ammonia) to protect against germs while minimizing traditional chlorine taste and odor. When used properly, chloramines typically have little or no noticeable smell, and ETWD regularly monitors disinfectant levels to stay within regulatory guidelines.