Drinking water directly from the tap is common for most people. However, certain contaminants found in tap water can pose health risks over time. Tap water in Los Angeles isn’t inherently unsafe, but knowing what’s actually in it can help you make informed decisions about filtration and testing. If you live in or around Los Angeles, you’re probably wondering: is LA tap water actually safe to drink? Here’s what the data shows.
Can You Drink Tap Water in LA?
Yes, you can drink tap water in Los Angeles. Nearly 4 million people are served by the Los Angeles Department of Water and Power (LADWP), one of the largest water utilities in the United States. That said, meeting legal drinking water standards doesn’t automatically mean the water is free of all contaminants of concern.
Los Angeles tap water meets federal and state legal limits, but it still contains detectable levels of several contaminants. The nonprofit Environmental Working Group (EWG) maintains a Tap Water Database that reports contaminant concentrations for utilities nationwide, compared against both federal legal limits and EWG’s own health-based guidelines, which are generally set more conservatively than the legal minimum — particularly for cancer risk.
A note on the specific numbers below: EWG updates its database periodically using multi-year testing averages, so exact multiples (how many times above a guideline a contaminant measures) shift somewhat with each release. The contaminants and general risk profile for LA water have stayed fairly consistent, but for the most current figures, it’s worth checking the EWG Tap Water Database directly for your specific utility.
Tap water in LA is primarily sourced from surface water hundreds of miles away, transported via aqueducts including the Los Angeles Aqueduct, the Colorado Aqueduct, and the State Water Project, then disinfected at treatment plants before reaching city taps. Recent EWG analysis has consistently found roughly two dozen detectable contaminants in the LADWP system, with several measuring above EWG’s health-based guidelines — though notably still within legal limits, which is the gap this article is meant to help you understand.
Which Contaminants Are in Los Angeles Tap Water?
The following are the contaminants most consistently flagged in Los Angeles tap water testing:
1. Arsenic
LA tap water has measured several hundred times above EWG’s health-based guideline for arsenic in recent testing cycles — reporting has ranged from roughly 400 to over 500 times the guideline depending on the specific release and system. Arsenic enters water through natural, industrial, and agricultural sources, including leaching from rock into groundwater. It’s classified as a known human carcinogen, with exposure linked to increased risk of lung, bladder, and skin cancer. It’s worth noting that arsenic’s legal limit and EWG’s health guideline are set very differently — LA water is within the legal limit while still measuring well above the more conservative health guideline.
2. Uranium
LA’s drinking water has measured several times above EWG’s health-based guideline for uranium. This radioactive contaminant is linked to kidney damage and cancer risk, and typically enters groundwater from natural deposits in the earth’s crust — a process that can be intensified by human activity such as uranium processing, mining, or gas and oil drilling.
3. Nitrate
This fertilizer-derived chemical has been detected in LA water at levels above EWG’s health guideline, and has been associated with increased risk of colorectal, thyroid, ovarian, kidney, and bladder cancer in some research. While nitrate contamination is often associated with rural agricultural areas, traces have been found in water systems serving both rural and urban parts of Los Angeles, partly due to imported water from agricultural regions via the State Water Project.
4. Hexavalent Chromium (Chromium-6)
Hexavalent chromium has been detected in LA water at levels above EWG’s health guideline. Research, including studies referenced by EWG’s ongoing chromium-6 tracking, has linked exposure to increased risk of stomach cancer.
5. Lead
Lead contamination varies significantly by neighborhood, depending on local infrastructure and plumbing materials rather than the water leaving the treatment plant. Aging infrastructure is the key risk factor in older neighborhoods, since lead pipes and lead solder were commonly used for decades before being phased out. Lead is a potent neurotoxin, and it’s particularly harmful to children’s intellectual development — there’s no known safe level of lead exposure.
6. Disinfection Byproducts
Several of the contaminants that exceed EWG’s health guidelines in LA water are disinfection byproducts — compounds like haloacetic acids (HAA5 and HAA9), bromate, and total trihalomethanes, which form when disinfectants like chlorine react with organic material in the water. These are a tradeoff of water treatment itself: disinfection prevents waterborne illness, but the byproducts carry their own long-term health considerations.
7. PFAS (“Forever Chemicals”)
PFAS (per- and polyfluoroalkyl substances) have become one of the most actively regulated contaminant categories in U.S. drinking water in recent years, with the EPA setting enforceable limits for several PFAS compounds. LA’s water system has generally reported lower PFAS levels than some other California utilities, but PFAS testing and regulation continue to evolve, and it’s a category worth checking directly in the EWG database or your utility’s latest Consumer Confidence Report, since results can vary by specific source and treatment plant.
Ensure Your LA Tap Water Is Safe With Professional Water Testing
Although Los Angeles tap water meets federal and state drinking water standards, contaminants can still enter your water through aging plumbing systems, damaged pipes, water heaters, or improperly maintained fixtures. The water quality leaving the treatment facility may differ meaningfully from what actually comes out of your tap, which is why professional testing is a valuable step for homeowners and businesses who want a complete picture rather than relying on utility-wide averages.
At The Mold Inspection Canary, we provide comprehensive drinking water testing services to help identify potential contaminants and verify whether your water is safe for consumption. Our experts analyze water samples for bacteria, chemicals, and other pollutants that may affect your health and property.
If your property has experienced flooding, plumbing leaks, or water damage, we also offer bacteria testing services to check for contamination risks and help ensure a safer indoor environment.
Whether you live in Los Angeles, Beverly Hills, Santa Monica, Malibu, or Pasadena, our team can help you evaluate your water quality and provide accurate recommendations based on professional testing results.
Don’t rely on assumptions about your tap water quality. Contact The Mold Inspection Canary today to schedule professional drinking water testing in Los Angeles and protect your home, family, or business.
FAQs
Is LA tap water actually unsafe to drink?
LA tap water meets all federal and state legal safety standards, so drinking it isn’t considered unsafe in the regulatory sense. Some contaminants do measure above EWG’s more conservative, health-based guidelines, which are generally set well below legal limits to minimize long-term cancer risk. Whether that gap matters to you personally is largely a question of risk tolerance and whether household members are in a more vulnerable group (infants, pregnant individuals, those with certain health conditions).
What’s the difference between a legal limit and EWG’s health guideline?
Legal limits (set by the EPA and California) reflect what’s enforceable and, in EWG’s view, haven’t been meaningfully updated in many contaminant categories in close to two decades. EWG’s health guidelines are typically far more conservative, aiming for a negligible added cancer risk rather than the higher risk threshold implicit in some legal limits. Water can legally comply while still measuring well above EWG’s guideline for a given contaminant.
Does a home water filter remove these contaminants?
It depends on the filter and the contaminant. Basic carbon pitcher filters can reduce some contaminants like chlorine byproducts but are less effective against dissolved metals and radioactive contaminants like arsenic and uranium. Reverse osmosis systems are generally the most effective option for removing a broad range of these contaminants, though they cost more upfront and require more maintenance.
Does my neighborhood affect what’s actually in my tap water?
Yes, significantly for some contaminants. Utility-wide testing reflects water quality at the treatment plant and various points in the distribution system, but what comes out of your specific tap can differ based on your home’s plumbing age and materials, especially for lead. This is one of the main reasons in-home testing gives a more accurate picture than city-wide averages alone.
How often should I test my tap water?
For homes on the public water supply, annual testing is a reasonable baseline, with additional testing after any plumbing work, a known local advisory, or if you notice a change in taste, smell, or color. If you’re specifically concerned about lead, testing is especially worthwhile in homes built before 1986, when lead plumbing materials were still commonly used.
