East Los Angeles 2023 Water Quality Report

District: East Los Angeles

A printable version of this report is also available.

Welcome

Rain splashing in a puddleCal Water is committed to providing a reliable supply of safe, clean water to our customers and communities, 24 hours per day, 7 days per week, 365 days per year. As water quality regulations have become more stringent, we have added or adjusted treatment to confirm that the water we deliver continues to meet or surpass all standards—because protecting our customers' health and safety is our highest priority.

In this system in 2023, we conducted 72,447 tests on 5,945 water samples for 237 constituents. We are pleased to confirm that we met every primary and secondary federal and state water quality standard last year.

But, our promise to provide quality, service, and value means more than just treating and testing water. It means having expert professionals available to assist with routine services safely and efficiently. It means having personnel available to handle emergencies around the clock. It means maintaining and upgrading the infrastructure needed to transport water from its source through a network of pumps, tanks, and pipes to your tap. It also means that, even with costs increasing across the country, we do everything we can to operate as efficiently as possible to keep your water service affordable.

I encourage you to read this year's water quality report, also called your Consumer Confidence Report, as it details any constituents detected in your water supply in 2023 and shows how your water compares to federal and state standards. It also provides information on hot topics and steps we take to protect your health and safety.

If you have any questions, we are here to help. You can contact your local office by phone or by using the Contact Us form. You can also get water service news on our web site and via our Facebook, X (formerly Twitter), and Instagram pages. If you're an account holder, you can find updates in your monthly bill and should keep your contact information up to date by visiting ccu.calwater.com to make sure you receive emergency and other important information.

Sincerely,
Jim Crawford, District Manager, East Los Angeles District

Action Items

There were no significant issues in your water system in 2023, and we have no recommended action items for our customers in this area.

East Los Angeles District
2000 South Tubeway Avenue
Commerce, CA 90040
(323) 722-8601

Your Water System

Tanks at a water plantCal Water has provided high-quality water utility services in the East Los Angeles area since 1928. In addition to the customers in our East Los Angeles system, we serve customers through an operating contract with the City of Commerce.

To meet our customers' needs, we use a combination of local groundwater and purchased water from the Metropolitan Water District of Southern California (MWD), which is obtained from the Colorado River and the State Water Project in northern California. The East Los Angeles water system currently includes 272 miles of pipeline, 11 active wells, 25 booster pumps, 17 storage tanks, and three MWD connections.

If you have any questions or concerns, please contact our local office by phone at (323) 722-8601 or through the Contact Us page.

Chloramines

Chloramines are most commonly formed when ammonia is added to chlorine. They are used as a disinfectant to treat your drinking water, and provide long-lasting disinfection as water moves through pipes to consumers.

Water Resource Sustainability

Cal Water helps our customers conserve water by offering programs and incentives to reduce indoor and outdoor water use, develop more efficient habits, and educate the next generation about the importance of managing water resources sustainably. We also continue to invest diligently in our infrastructure to reduce the amount of water lost to pipeline leaks and, in 2022, completed an updated assessment of the impacts of climate change on water supply and demand. Whether in wet or dry years, it's important that we make saving water every day a way of life. Using water wisely will ensure that we have enough water in periods of drought and for generations to come.

Visit the conservation page for details.

The Water Quality Lab

Test tubes with water in themWater professionals collect samples from throughout the water system for testing at our newly upgraded, state-of-the-art water quality laboratory, which is certified each year through the stringent Environmental Laboratory Accreditation Program (ELAP).

Our laboratory team tests the water for 326 constituents with equipment so sensitive it can detect levels as low as one part per trillion. In order to maintain the ELAP certification, all of our scientists must pass blind-study proficiency tests for every water quality test performed. Water quality test results are entered into our Laboratory Information Management System (LIMS), a sophisticated software program that enables us to react quickly to changes in water quality and analyze water quality trends in order to plan effectively for future needs.

Cross-Connection Control

So that the high-quality water we deliver is not compromised in the distribution system, Cal Water has a robust cross-connection control program in place. Cross-connection control is critical to making sure that activities on customers' properties do not affect the public water supply. Our cross-connection control specialists ensure that all of the existing backflow prevention assemblies are tested annually, assess all connections, and enforce and manage the installation of new commercial and residential assemblies.

Backflow can occur when certain pressure conditions exist either in our distribution system or within the customer's plumbing, so our customers are our first line of defense. A minor home improvement project—without the proper protections—can create a potentially hazardous situation, so careful adherence to plumbing codes and standards will keep the community's water supply remains safe. Please be sure to utilize the advice or services of a qualified plumbing professional.

Many water-use activities involve substances that, if allowed to enter the distribution system, would be aesthetically displeasing or could even present health concerns.

Some common cross-connections are:

  • Garden hoses connected to a hose bib without a simple hose-type vacuum breaker (available at a home improvement store).
  • Improperly installed toilet tank fill valves that do not have the required air gap between the valve or refill tube.
  • Landscape irrigation systems that do not have the proper backflow prevention assembly installed on the supply line.

The list of materials that could potentially contaminate the water system is vast. According to the United States Environmental Protection Agency (EPA), a wide variety of substances have contaminated drinking water systems throughout the country as a result of poor cross-connection control. Examples include:

  • Antifreeze from a heating system.
  • Lawn chemicals from a garden hose or sprinkler head.
  • Blue water from a toilet tank.
  • Carbonated water from a soda dispenser.

Customers must ensure that all plumbing is in conformance with local plumbing codes. Additionally, state law requires certain types of facilities to install and maintain backflow prevention assemblies at the water meter. Cal Water's cross-connection control staff will determine whether you need to install a backflow prevention assembly based on water uses at your location.

DWSAPP

Dishes in soapy waterWe encourage customers to join us in our efforts to prevent water pollution and protect our most precious natural resource.

By the end of 2003, Cal Water had submitted to the Division of Drinking Water (DDW) a Drinking Water Source Assessment and Protection Program (DWSAPP) report for each water source in the water system. The DWSAPP report identifies possible sources of contamination to aid in prioritizing cleanup and pollution prevention efforts. All reports are available for viewing or copying at our office.

The water sources in the East Los Angeles system are considered most vulnerable to contamination from:

  • Gas stations
  • Confirmed leaks
  • Known contaminant plumes
  • Chemical/petroleum storage
  • Metal fabrication
  • Plastic producers

Your 2023 Results

Fluoride

State law requires Cal Water to add fluoride to drinking water if public funding is available to pay for it, and it is a practice endorsed by the American Medical Association and the American Dental Association to prevent tooth decay. In this area, local water is blended with purchased water that has fluoride in it. Show the table in this report to your dentist to see if he or she recommends giving your children fluoride supplements.

More information about fluoridation, oral health, and related issues can be found on the DDW web site.

For general information on water fluoridation, visit the Fluoride page.

Water Hardness

Hardness is a measure of the magnesium, calcium, and carbonate minerals in the water. Water is considered soft if its hardness is less than 75 parts per million (ppm), moderately hard at 75 to 150 ppm, hard between 150 and 300 ppm, and very hard at 300 ppm or higher.

Hard water is generally not a health concern, but it can have an impact on how well soap lathers and is significant for some industrial and manufacturing processes. Hard water may also lead to mineral buildup in pipes or water heaters.

Some people with hard water opt to buy a water softener for aesthetic reasons; however, some water softeners add salt to the water, which can cause problems at wastewater treatment plants. Additionally, people on low-sodium diets should be aware that some water softeners increase the sodium content of the water.

For more information on water hardness, see the water hardness video.

Possible Contaminants

Water pouring into a glassAll drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk.

More information about contaminants and potential health effects can be obtained by calling the EPA Safe Drinking Water Hotline at (800) 426-4791.

The sources of drinking water (both tap and bottled) include rivers, lake, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals—and in some cases radioactive material—and can pick up substances resulting from the presence of animals or human activities. Prior to entering the distribution system, source water with constituents over maximum contaminant levels is treated to reduce levels to meet standards set by public health experts.

Contaminants that may be present in source water include:

  • Microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
  • Inorganic contaminants, such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
  • Pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses.
  • Organic chemical contaminants, including synthetic and volatile organic compounds, which are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural applications, and septic systems.
  • Radioactive contaminants, which can be naturally occurring or the result of oil and gas production and mining activities.

In order to keep tap water safe to drink, the EPA and DDW prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water, which must provide the same protection for public health.

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised people, such as those with cancer undergoing chemotherapy, those who have undergone organ transplants, and those with HIV/AIDS or other immune system disorders; some elderly people; and infants can be particularly at risk from infections. These people should seek advice from their health care providers about drinking water contaminants. EPA and Centers for Disease Control and Prevention (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline.

About Lead

Horizon over a lakeAs the issue of lead in water continues to be top of mind for many Americans, Cal Water wants to assure you about the quality of your water. We are compliant with health and safety codes mandating use of lead-free materials in water system replacements, repairs, and new installations. We have no known lead service lines in our systems. We test and treat (if necessary) water sources to confirm that the water delivered to customer meters meets all water quality standards and is not corrosive toward plumbing materials.

The water we deliver to your home meets lead standards. However, if present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing (for example, lead solder used to join copper plumbing, and brass and other lead-containing fixtures).

Cal Water is responsible for providing high-quality drinking water to our customers' meters, but cannot control the variety of materials used in properties' plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking.

If you are concerned about lead in your water, you may wish to have your water tested by a certified lab. More information about lead in drinking water can be found through the Safe Drinking Water Hotline (1-800-426-4791) or at www.epa.gov/safewater/lead.

Testing for Lead in Schools

The State of California required that all public schools built before 2010 test for lead in their drinking water by July 1, 2019. We are committed to supporting our school districts' efforts to protect students and ensure that the drinking water at their school sites are below regulatory limits. We worked with all school districts in our service area that serve kindergarten through 12th grade to develop sampling plans, test samples, and conduct follow-up monitoring, if needed, for corrective actions.

Please see our Testing for Lead in Schools web page for more information. For specific information regarding local school data, see the state web portal lead sampling in schools page.

Lead and Copper Rule

The Lead and Copper Rule requires us to test water inside a representative number of homes that have plumbing most likely to contain lead and/or lead solder to determine the presence of lead and copper or any action level exceedance. An action level is the concentration of a contaminant which, when exceeded, triggers corrective actions before it becomes a health concern. If action levels are exceeded, either at a customer's home or system-wide, we work with the customer to investigate the issue and/or implement corrosion control treatment to reduce lead levels.

Lead Service Line Inventory (LSLI)

Protecting our customers' health and safety is our highest priority. As part of this commitment, we have been working to identify and replace any old customer water service lines and fittings that may contain lead. California Senate Bill (SB) 1398 required all water utilities in California to develop an inventory of all distribution service line materials, and submit a list of known lead service lines to the state by 2018. A list of unknown service lines that may contain lead, along with a plan for replacement, was due to the state by July 1, 2020. Known lines must be replaced as soon as possible.

More information regarding LSLI and specific data for each water system can be found on the health and safety code page of the state web site.

In your system, results from our lead monitoring program, conducted in accordance with the Lead and Copper Rule, were below the action level for the presence of lead.

PFAS

Water glass and pitcherIn April 2024, the EPA adopted the final water quality regulation for certain per- and polyfluoroalkyl substances (PFAS):

  • MCL of 4 ppt for PFOS and PFOA.
  • MCL of 10 ppt for PFHxS, PFNA, and GenX.
  • Hazard Index of 1.0 combined for PFHxS, PFNA, PFBS, and GenX.

Water systems must begin monitoring for these PFAS within three years (2027), and must comply with the regulation within five years (2029).

At Cal Water, protecting our customers' health and safety is our highest priority, and we are committed to complying with all requirements set by the public health experts. We have been preparing for the EPA regulation and its potential impact on—and any treatment needed in—our systems, and already evaluated the impact of the proposed regulation so that we could be better prepared to comply with the final MCLs.

We also have protocols to test our water sources for compliance with the new MCLs. We have long followed recommendations from DDW, and even went beyond by testing every active source in our California systems years ago. Although not required at the time, we believed it was the right thing to do. In any cases across our service areas where detections were above the levels at which state public health experts have recommended water suppliers take action (the previous response level), we took the affected sources out of service until treatment was/can be installed.

Our active water sources are in compliance with current California response levels, based on the running annual average at each site. The response level, which is the level at which a water system should make operational changes to reduce the concentration of a compound, is set with a margin of protection for all people (including sensitive populations) over a lifetime of exposure.

Additionally, we believe a comprehensive approach is needed to properly address the situation. We urged the EPA to establish a consistent, science-based standard as quickly as feasible, and strongly supported state legislation that will prohibit the sale and use of certain products that contain PFAS, require the certification of accurate testing methods for PFAS, and establish a publicly accessible database that houses the sources of PFAS entering water supplies. We have also filed lawsuits to hold PFAS manufacturers responsible—and ultimately prevent our customers from bearing the costs of treatment, to the extent possible—and are pursuing grants where available to further offset customer cost impacts.

As background, PFAS are manmade compounds that have been used to make carpets, clothing, fabrics for furniture, paper packaging for food, and other materials (e.g., cookware) that are resistant to water, grease, or stains. These compounds are also used for firefighting at airfields, which is one way they have found their way into groundwater in certain areas.

Studies indicate that long-term exposure to PFAS over certain levels could have adverse health effects, including developmental effects to fetuses during pregnancy or infants; cancer; or impacts on liver, immunity, thyroid, and other functions. Potential health effects related to PFAS are still being studied, and research is still evolving on this issue.

More information on PFAS is available on the DDW web site.

Key Definitions

Woman drinking a glass of waterIn Compliance: Does not exceed any applicable MCL, SMCL, or action level, as determined by DDW. For some compounds, compliance is determined by averaging the results for one source over a one-year period.

Level 1 Assessment: A Level 1 assessment is a study of the water system to identify potential problems and determine (if possible) why total coliform bacteria have been found in the system.

Level 2 Assessment: A Level 2 assessment is a very detailed study of the water system to identify potential problems and determine (if possible) why an E. coli MCL violation has occurred and/or why total coliform bacteria have been found in the system on multiple occasions.

Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible. Secondary MCLs (SMCLs) are set to protect the odor, taste, and appearance of drinking water.

Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by the U.S. Environmental Protection Agency.

Maximum Residual Disinfectant Level (MRDL): The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

Maximum Residual Disinfectant Level Goal (MRDLG): The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Notification Level (NL) and Response Level (RL): Health-based advisory levels for unregulated contaminants in drinking water. They are used by DDW to provide guidance to drinking water systems.

Primary Drinking Water Standards (PDWS): MCLs, MRDLs, and TTs for contaminants that affect health along with their monitoring, reporting, and water treatment requirements.

Public Health Goal (PHG): The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency without regard to technological or economic feasibility.

Regulatory Action Level (AL): The concentration of a contaminant which, if exceeded, triggers treatment or other requirements that a water system must follow.

Treatment Technique (TT): A required process intended to reduce the level of a contaminant in drinking water.

Variances and Exemptions: Permissions from the State Water Resources Control Board (State Board) to exceed an MCL or not comply with a treatment technique under certain conditions.

Standard Abbreviations

  • AL: Action level
  • Max: Maximum
  • MFL: Million fibers per liter
  • Min: Minimum
  • N/A: Not applicable
  • ND: Constituent not detected
  • NL: Notification level
  • NTU: Nephelometric turbidity unit
  • pCi/L: Picocuries per liter (a measure of radiation)
  • ppb: Parts per billion or micrograms per liter (µg/L)
  • ppm: Parts per million or milligrams per liter (mg/L)
  • ppq: Parts per quadrillion or picogram per liter (pg/L)
  • ppt: Parts per trillion or nanograms per liter (ng/L)
  • RAA: running annual average
  • µS/cm: Microsiemens/centimeter

Table Introduction

Eyedropper putting water in a test tubeEvery year, Cal Water performs hundreds of thousands of tests to monitor the quality of our water. If any contaminants are detected, they are included in this annual water quality report. However, most of the contaminants we test for are not detected, so they are not listed.

See the Potential Contaminants web page for a complete list of contaminants we test for.

In the table, water quality test results are divided into four major sections: "Primary Drinking Water Standards," "Secondary Drinking Water Standards," "State-Monitored Contaminants with Notification Levels," and "Unregulated Compounds." Primary standards protect public health by limiting the levels of certain constituents in drinking water. Secondary standards are set for substances that don't impact health but could affect the water's taste, odor, or appearance. Some unregulated substances (hardness and sodium, for example) are included for your information. The State allows us to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some of our data, though representative, are more than one year old.

Substance Sources

  • CF: Discharge from industrial chemical factories
  • DI: Byproduct of drinking water disinfection
  • DK: Decay of natural and manmade deposits
  • DS: Drinking water disinfectant added for treatment
  • EN: Naturally present in the environment
  • ER: Erosion of natural deposits
  • FD: Discharge from factories, dry cleaners, and auto shops (metal degreaser)
  • FE: Human and animal waste
  • FL: Water additive that promotes strong teeth; discharge from fertilizer and aluminum factories
  • FR: Runoff and leaching from fertilizer use; leaching from septic tanks and sewage
  • IC: Internal corrosion of household plumbing systems
  • IM: Discharge from industrial manufacturers
  • IO: Substances that form ions when in water
  • IW: Industrial waste
  • MD: Discharge from metal-degreasing sites and other factories
  • OC: Runoff from orchards; glass and electronics production waste
  • OD: Discharges of oil-drilling waste and from metal refineries
  • OM: Naturally occurring organic materials
  • PR: Inorganic chemical used in solid rocket propellant, fireworks, explosives, flares, matches, and a variety of industries; usually gets into drinking water as a result of environmental contamination from historic aerospace or other industrial operations that used or use, store, or dispose of perchlorate and its salts
  • RU: Runoff/leaching from natural deposits
  • RS: Residue from some surface water treatment processes
  • SO: Soil runoff
  • SW: Seawater influence
  • WD: Leaching from wood preservatives
  • UR: Unregulated constituents with no source listed and that do not have standardized "source of substance" language

Our testing equipment is so sensitive, it can detect constituents as small as 1 part per trillion. That is equivalent to 1 inch over 15 million miles.

2022 Water Quality

Primary Drinking Water Standards

Microbiological Year Tested Unit MCL PHG (MCLG) In Compliance Distribution System-Wide Source
Highest Monthly
Fecal coliform and E. coli 2023 Positive Samples 01 (0) Yes 0 FE
Radiological Year Tested Unit MCL PHG (MCLG) In Compliance Groundwater Central Basin MWD2 Source
Range Average Range Average
Gross alpha particle activity 2020–2023 pCi/L 15 (0) Yes ND–3.4 ND N/A ND ER
Gross beta particle activity 2023 pCi/L 50 0 Yes N/A N/A ND–6 ND DK
Uranium 2016–2023 pCi/L 20 0.43 (0) Yes ND–2.8 1.5 ND–3 1 ER
Inorganic Chemicals Year Tested Unit MCL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range Average Range Average
Aluminum 2023 ppb 1000 600 Yes ND ND ND–83 57.5 ER, RS
Arsenic3 2021–2023 ppb 10 0.004 (0) Yes ND–5.3 ND ND ND ER, OC
Barium 2021–2023 ppm 1 2 (2) Yes ND–0.15 ND ND ND ER, OD
Fluoride 2023 ppm 2 1 (4.0) Yes 0.20–0.70 0.35 0.6–0.8 0.7 ER, FL
Nitrate as N4 2023 ppm 10 10 (10) Yes ND–8.0 3.2 0.8–1.0 0.9 ER, FR
Perchlorate 2023 ppb 6 1 Yes ND–2.4 ND ND ND PR
Lead and Copper Year Tested Unit AL PHG (MCLG) In Compliance Distribution System-Wide Source
90th Percentile Samples > AL
Copper 2023 ppm 1.3 0.3 Yes 0.33 0 of 53 IC, ER, WD
Lead 2023 ppb 15 0.2 Yes ND 0 of 53 IC, IM, ER
Volatile Organic Compounds Year Tested Unit MCL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range Average Range/ Result Average
1,1-Dichloroethylene (1,1-DCE) 2023 ppb 6 10 (7) Yes ND–1.9 ND ND ND CF
Tetrachloroethylene (PCE) 2023 ppb 5 0.06 (0) Yes ND–1.1 ND ND ND FD
Trichloroethylene (TCE) 2023 ppb 5 1.7 (0) Yes ND–1.4 ND ND ND MD
Disinfection Byproducts Year Tested Unit MCL PHG (MCLG) In Compliance Distribution System-Wide Source
Range Highest Annual Average
Total haloacetic acids (THAA) 2023 ppb 60 N/A Yes ND–12 6.7 DI
Total trihalomethane (TTHM) 2023 ppb 80 N/A Yes ND–28 16 DI
Disinfectants Year Tested Unit MRDL MRDLG In Compliance Distribution System-Wide Source
Range Average
Total chlorine 2023 ppm 4 4 Yes 0.20–2.9 2.0 DS
Surface Water—Turbidity Year Tested Unit MCL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Highest Level Lowest Monthly Percent ≤ 0.3 Highest Level Lowest Monthly Percent ≤ 0.3
Turbidity5 2023 NTU TT N/A Yes N/A N/A 0.06 100 SO
Surface Water—Total Organic Carbon (TOC) Year Tested Unit MCL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range Average Range Average
Total organic carbon6 2023 NTU TT N/A Yes N/A N/A 1.4–3.0 2.25 SO

Secondary Drinking Water Standards

Contaminants Year Tested Unit SMCL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range/ Result Average Range/ Result Average
Aluminum 2023 ppb 200 600 Yes ND ND ND–83 57.5 ER, RS
Chloride 2021–2023 ppm 500 N/A Yes 34–140 85 34–58 48.5 RU, SW
Color 2021–2023 UNITS 15 N/A Yes ND–5.0 ND 1 1 OM
Manganese7 2021–2023 ppb 50 N/A Yes ND–98 ND ND ND RU
Odor 2017–2023 T.O.N. 3 N/A Yes ND–2.0 ND 2 2 OM
Specific conductance 2021–2023 US 1600 N/A Yes 560–970 789 357–604 512 SW, IO
Sulfate 2021–2023 ppm 500 N/A Yes 74–110 96 51–112 83 RU, IW
Total dissolved solids 2021–2023 ppm 1000 N/A Yes 350–580 501 209–367 307 RU
Turbidity (groundwater) 2021–2023 NTU 5 N/A Yes ND–0.75 0.14 N/A N/A SO

State-Regulated Contaminants with Notification Levels

Contaminants Year Tested Unit NL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range/ Result Average Range/ Result Average
1,4-Dioxane8 2017–2023 ppb 1 N/A Yes ND–5.9 3.3 N/A N/A UR
Boron 2016–2023 ppm 1 N/A Yes 0.11–0.24 0.18 0.14–0.19 0.16 UR
Chlorate 2023 ppb 800 N/A Yes N/A N/A ND–19 9.5 UR
Methyl isobutyl ketone 2019–2023 ppb 120 N/A Yes ND–7.6 ND N/A N/A UR
N-nitrosodimethylamine (NDMA) 2020–2023 ppt 10 3 Yes ND ND ND–3.5 1.7 UR
Perfluorobutanesulfonic acid (PFBS)9 2020–2023 ppt 500 N/A Yes ND–8.7 0.54 ND ND UR
Perfluorhexanesulfonic acid (PFHxS)2,10 2020–2023 ppt 3 N/A Yes ND–8.9 3.1 ND ND UR
Perfluorooctanoic acid (PFOA)2,3 2020–2023 ppt 5.1 N/A Yes ND–9.6 3.2 ND ND UR
Perfluorooctanesulfonic acid (PFOS)2,11 2020–2023 ppt 6.5 N/A Yes ND–45 11 ND ND UR
Vanadium 2020–2023 ppb 50 N/A Yes ND–4.7 ND 3.4–3.9 3.6 UR

Unregulated Compounds and Unregulated Contaminant Monitoring Rule (UCMR)12

Constituents Year Tested Unit NL PHG (MCLG) In Compliance Groundwater Central Basin MWD Source
Range/ Result Average Range/ Result Average
Alkalinity (total) 2021–2023 ppm N/A N/A N/A 64–220 170 65–102 83 UR
Calcium 2016–2023 ppm N/A N/A N/A 59–97 77 20–40 32 UR
Hexavalent chromium 2020–2023 ppb N/A 0.02 N/A ND–1.9 1.1 ND ND UR
Haloacetic acids five 2020 ppb N/A N/A N/A ND–8.6 2.9 N/A N/A UR
Haloacetic acids nine 2020 ppb N/A N/A N/A ND–14 5.3 N/A N/A UR
Haloacetic acids six brominated 2020 ppb N/A N/A N/A ND–7.5 2.8 N/A N/A UR
Hardness (total) 2016–2023 ppm N/A N/A N/A 210–320 248.5 81–153 124 UR
Lithium 2023 ppb N/A N/A N/A ND ND ND–13 ND UR
Magnesium 2016–2023 ppm N/A N/A N/A 11–23 18 7.8–13 10.5 UR
Perfluorobutanoic acid (PFBA) 2023 ppt N/A N/A N/A ND–7.8 3.9 ND ND UR
Perfluorohexanoic acid (PFHxA) 2020–2023 ppt N/A N/A N/A ND–13 1.5 ND ND UR
Perfluoropentanoic acid 2023 ppt N/A N/A N/A ND–14 2.6 ND ND UR
Perfuoroheptanoic acid (PFHpA) 2020–2023 ppt N/A N/A N/A ND–4.1 0.26 ND ND UR
pH 2017–2023 Units N/A N/A N/A 6.4–8.8 7.5 8.2–8.6 8.5 UR
Potassium 2016–2023 ppm N/A N/A N/A 2.3–3.8 2.8 2.4–3.0 2.65 UR
Sodium 2016–2023 ppm N/A N/A N/A 31–88 67 39–68 56 UR

1: Exceeds if routine and repeat samples are total coliform-positive and either is E. coli-positive, system fails to take repeat samples following E. coli-positive routine sample, or system fails to analyze total coliform-positive repeat sample for E. coli.

2: Part of the system's water supply is purchased from Metropolitan Water District of Southern California (MWD) via the Central Basin Municipal Water District (Central Basin MWD).

3: The average arsenic level was ND, with a maximum level of 5.3 ppb. While your drinking water meets the federal and state standards for arsenic, it does contain low levels of arsenic. The arsenic standards balance the current understanding of arsenic's possible health effects against the costs of removing arsenic from drinking water. The EPA continues to research the health effects of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects, such as skin damage and circulatory problems.

4: The average nitrate as N level was 3.2 ppm, with a maximum level of 8 ppm. We are closely monitoring the nitrate levels. Nitrate in drinking water at levels above 10 ppm is a health risk for infants of less than six months of age. Such nitrate levels in drinking water can interfere with the capacity of an infant's blood to carry oxygen, resulting in a serious illness; symptoms include shortness of breath and blueness of the skin. Nitrate levels above 10 ppm may also affect the ability of the blood to carry oxygen in other individuals, such as pregnant women and those with certain specific enzyme deficiencies. If you are caring for an infant or you are pregnant, you should seek advice from your health care provider.

5: For surface water systems, the TT dictates that the turbidity level of the filtered water be less than or equal to 0.3 NTU in 95% of measurements taken each month.

6: TOC has no health effects; however, TOC provides a medium for the formation of disinfection byproducts. These byproducts include trihalomethanes and haloacetic acids. The TT dictates that a removal ratio of 1 or higher must be achieved. Drinking water containing these byproducts in excess of the MCL may lead to adverse health effects such as liver, kidney, or nervous system problems, and may lead to an increased risk of cancer. Concerns regarding disinfection byproducts are based upon exposure over many years.

7: In one sample in the East Los Angeles system, manganese exceeded the SMCL of 50 ppb. The RAA is less than the SMCL. Compliance with the SMCL is based on RAA. We are monitoring the levels to confirm we do not exceed the SMCL RAA. The SMCL was set to protect you against unpleasant aesthetic effects, such as color, taste, odor, and the staining of plumbing fixtures and clothing when washed. Exceeding the SMCL does not pose a health risk.

8: Some groundwater wells contain 1,4-dioxane at levels greater than the NL established by DDW. An NL is defined as a health-based advisory level for an unregulated contaminant in drinking water. DDW uses it to provide guidance to drinking water systems. DDW recommends taking a well out of service if the concentrations in the well exceed 35 times the NL. Based on laboratory studies, some people who consume water containing 1,4-dioxane over many years may experience liver or kidney problems and may have a heightened cancer risk.

9: Per-and polyfluoroalkyl substances (PFAS) are a broad class of chemicals, which includes PFOA and PFOS, PFBS, and PFHxS. NLs have been established for these four compounds. NLs are non-regulatory, health-based advisory levels established for constituents that may be candidates for regulation in the future. Studies indicate that long-term exposure to PFOS/PFOA/PFHxS over certain levels could have adverse health effects, including developmental effects to fetuses during pregnancy or breastfed infants; cancer; or liver, immunity, thyroid, and other effects. Cal Water is working closely with DDW and EPA to conduct extensive monitoring and identify the best available treatment technology for treatment of PFAS.

10: While PFAS concentrations are ND in the treated water distributed to customers, the raw well water had one or more PFAS detections above the NL. The raw well water is treated for PFAS via the existing granular-activated carbon (GAC) treatment facility installed to treat other contaminants. Cal Water is currently in the process of obtaining a permit to treat for PFAS using GAC.

11: PFOS exceeded the RL in 3 samples collected at well 13-02 in the fourth quarter of 2023. The RL is the level at which it is recommended that the water supplier take action. Well 13-02 was removed from service in February 2024. Compliance is based on the RAA. The RAA is less than the RL.

12: While PFAS concentrations are ND in the treated water distributed to customers, the raw well water had one or more PFAS detections above the NL. The raw well water is treated for PFAS via the existing granular-activated carbon (GAC) treatment facility installed to treat other contaminants. Cal Water is currently in the process of obtaining a permit to treat for PFAS using GAC.

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