Is Los Angeles tap water safe to drink?
In the latest results, every contaminant we list with a single federal limit was below that limit or action level. Lead was 3.9 ppb at the 90th percentile, below the 15 ppb action level. EPA’s goal for lead is zero. Lithium was found above EPA’s health reference level (10 ppb), a screening value that is not an enforceable limit. EPA lists 1 health-based violation in the last 10 years, the latest in Jan 2018. See how US tap water compares nationally.
What’s in Los Angeles tap water
Latest results from LADWP’s 2025 report and EPA records. One row per contaminant, with the type of limit in the limit column.
| Contaminant | Result | Limit | Sampled | Source |
|---|---|---|---|---|
| LeadComes mostly from home plumbing, not from the source water. | 3.9 ppb 90th percentile of 105 home taps; 3 above the action level | 15 ppbAction level · goal 0Drops to 10 ppb on Nov 1, 2027 (Lead and Copper Rule Improvements). | 2023 | LADWP 2025 Drinking Water Quality Report |
| CopperFrom corrosion of household copper pipes. | 529 ppb 90th percentile of 105 home taps; none above the action level | 1,300 ppbAction level · goal 1,300 | 2023 | LADWP 2025 Drinking Water Quality Report |
| PFOA and PFOS (PFAS)Two “forever chemicals” with a federal limit. | Not detected 16 samples at 4 entry points; none at or above the reporting level (4 ppt) | 4.0 ppt eachLegal limit (MCL) · goal 0Utilities must comply from 2029; EPA proposed 2031 in May 2026. | Dec 2023 – Sep 2024 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
| ArsenicOccurs naturally in rock and soil. | 7.0 ppb Highest level detected in 2025 | 10 ppbLegal limit (MCL) · goal 0 | 2025 | LADWP 2025 Drinking Water Quality Report |
| Nitrate (as N)From fertilizer runoff and septic systems. | Up to 1.4 mg/L range <0.4–1.4 | 10 mg/LLegal limit (MCL) · goal 10 | 2025 | LADWP 2025 Drinking Water Quality Report |
| Total trihalomethanesByproducts of disinfection. | 33.8 ppb Highest locational running annual average; range 15.2–35.2 | 80 ppbLegal limit (MCL) | 2025 | LADWP 2025 Drinking Water Quality Report |
| Haloacetic acids (HAA5)Byproducts of disinfection. | 13.4 ppb Highest locational running annual average; range 4–14.7 | 60 ppbLegal limit (MCL) | 2025 | LADWP 2025 Drinking Water Quality Report |
| Chloramine (as total chlorine)Disinfectant kept in the pipes on purpose. | 1.7 mg/L Average; range 1.4–2 | 4.0 mg/LDisinfectant limit (MRDL) · goal 4 | 2025 | LADWP 2025 Drinking Water Quality Report |
| LithiumUnregulated; EPA is collecting national data. | Up to 100 ppb Found in 16 of 16 samples at 4 entry points; range 9.9–100 | 10 ppbEPA health reference levelA health reference level is a screening value, not an enforceable limit. | Dec 2023 – Sep 2024 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
ppb = parts per billion (µg/L), ppt = parts per trillion (ng/L). The bar shows the result against the limit (black line). Limits: EPA drinking water regulations, PFAS rule, Lead and Copper Rule Improvements. “Not detected” means below the lab’s reporting level, not zero.
EPA violations
EPA’s SDWIS database lists 4 violation records for LADWP since 2016, 2 of them health-based. All have a return-to-compliance date.
Not listed: 2 older monitoring, reporting or notice records (2016), none health-based.
Shown: health-based violations and everything from the last 10 years. Source: EPA SDWIS record, CA1910067, retrieved Oct 13, 2026.
How hard is Los Angeles water?
Hardness depends on which supply reaches your area: Los Angeles Aqueduct water is the softest, water from MWD’s Weymouth and Diemer plants the hardest.
| Los Angeles Aqueduct Filtration Plant | 103 mg/L · 6.0 gpg (96–117) |
| Northern Combined Wells | 115 mg/L · 6.7 gpg (78–151) |
| Southern Combined Wells | 116 mg/L · 6.8 gpg (83–159) |
| MWD Jensen Plant | 140 mg/L · 8.2 gpg (137–142) |
| MWD Weymouth Plant | 234 mg/L · 13.7 gpg (189–280) |
| MWD Diemer Plant | 236 mg/L · 13.8 gpg (191–280) |
The utility’s figures cover the whole system. To test the hardness at your tap, strips or a drop kit take minutes.
Classes: USGS (0–60 mg/L soft, 61–120 moderately hard, 121–180 hard, above 180 very hard). 1 gpg = 17.1 mg/L as calcium carbonate. Source: LADWP 2025 Drinking Water Quality Report.
What to do with these numbers
Only what the data above points to.
Lead comes from home plumbing
EPA’s goal for lead is zero. LADWP reports no lead service lines in its system and holds a non-lead designation from the California State Water Board. Older faucets, lead solder and lead service lines can add lead at your tap. A filter certified to NSF/ANSI 53 for lead reduces it.
Certified to reduce lead. Lead is not necessarily in your water.
All filters compared →Hard water in parts of Los Angeles
Above 120 mg/L (7.1 gpg) USGS calls water hard. Hardness has no federal health limit, but it leaves scale in kettles, water heaters and on fixtures. Filters for lead or chloramine do not reduce it. A water softener at the main line does.
Whole-house systems compared →Chloramine taste and smell
LADWP disinfects with chloramine on purpose, below the 4.0 mg/L limit. If you dislike the taste, look for a filter certified to NSF/ANSI 42 for chloramine. For home dialysis and aquariums it must be reduced first.
Certified to reduce chloramine.
Under-sink filters compared →Test your own water
LADWP’s numbers come from its own sampling sites. A certified lab test of your faucet shows lead and copper from your plumbing and the chloramine level at your tap. How to test your own tap for lead, starting with your water utility.
All water tests compared →