LADWP Water Quality Report Decoded: What Your 2026 CCR Actually Means

Every July, LADWP mails out its Drinking Water Quality Report, the Consumer Confidence Report (CCR) required under the federal Safe Drinking Water Act. Most Los Angeles residents glance at the envelope, see that their water "meets all federal and state standards," and throw it out. That is a mistake, because the CCR contains specific data points that do matter for your home, and the gap between "meets standards" and "good for my family" is larger than most people realize.

This guide walks through the 2024 LADWP DWQR (published July 2025, the most recent full-year report as of spring 2026), explains what each major section means, and tells you which numbers actually warrant action.

Where LADWP's Water Actually Comes From

The 2024 report breaks LADWP's supply into four sources: imported water from the Metropolitan Water District (MWD), which blends State Water Project (SWP) water from Northern California with Colorado River water, accounted for roughly 73% of supply; the Los Angeles Aqueduct (LAA) drawing from the Eastern Sierra supplied approximately 15%; local groundwater from the San Fernando, Sylmar, Central, and West Coast Basins contributed about 10%; and recycled water contributed roughly 2%.

This blend shifts year over year based on Sierra snowpack, Colorado River shortage declarations, and local groundwater availability. In wet years with strong LAA flow, imported water drops and LAA rises. In dry years, as LADWP pulls more from MWD's Colorado River-heavy supply, TDS and hardness at your tap both rise.

Understanding MCL vs. MCLG

Every contaminant row in the CCR lists two numbers: an MCL and an MCLG. MCL (Maximum Contaminant Level) is the enforceable legal limit set by the EPA, derived from both health risk assessment and technological/economic feasibility. MCLG (Maximum Contaminant Level Goal) is the aspirational health-based target. For known carcinogens, the MCLG is typically set at zero. The MCLG for PFOA and PFOS is zero. The MCL is 4 parts per trillion. The gap between those two numbers is the gap between "safe in an idealized health-only analysis" and "what can realistically be achieved at the treatment plant."

For homeowners: if a contaminant's measured level is well below its MCL but near or above its MCLG, it is legally acceptable but may still be worth addressing at your tap.

The Contaminants That Actually Matter in 2026

Chromium-6 (Hexavalent Chromium)

California adopted its hexavalent chromium MCL of 10 micrograms per liter (10 parts per billion) on April 17, 2024, with the regulation taking effect October 1, 2024. The federal EPA standard is only a total-chromium limit of 100 ppb; California's standard is specifically for the carcinogenic hexavalent form.

This matters in Los Angeles because the San Fernando Basin, one of LADWP's local groundwater sources, has a well-documented legacy of hexavalent chromium contamination from decades of aerospace and industrial activity. In wells drawing from this basin, chromium-6 has accounted for 61 to 100 percent of total chromium. LADWP has built and is expanding dedicated chromium-6 treatment facilities to bring groundwater into compliance. Chromium-6 is removed by reverse osmosis at point of use and by specific adsorptive media at the treatment plant. Standard carbon filters do not remove chromium-6.

PFAS (Forever Chemicals)

The EPA finalized the first-ever federal PFAS drinking water rule on April 10, 2024, setting enforceable Maximum Contaminant Levels of 4.0 parts per trillion for PFOA and 4.0 ppt for PFOS. The MCLG for both is zero. The original compliance deadline of 2029 was extended in May 2025 to 2031 for PFOA/PFOS; the EPA also announced it will rescind previously finalized MCLs for PFHxS, PFNA, GenX, and PFBS pending further rulemaking. Initial monitoring data submission is due by 2027.

If your CCR shows any PFAS detection, even below the MCL, a home reverse osmosis system provides an additional barrier that drops detectable PFAS to near-zero at your drinking water tap.

Trihalomethanes (TTHMs) and Haloacetic Acids (HAA5)

These are disinfection byproducts formed when chlorine or chloramine reacts with naturally occurring organic matter in source water. The federal MCLs are 80 µg/L for TTHMs and 60 µg/L for HAA5. TTHMs include chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Long-term exposure is associated with elevated bladder cancer risk. TTHMs are volatile, they off-gas during showering, meaning your inhalation exposure in an enclosed hot shower can be substantial. A whole-house carbon filter, particularly catalytic carbon, reduces TTHMs throughout the home including in shower steam.

Lead and Copper

The Lead and Copper Rule Improvements (LCRI), finalized October 8, 2024 and effective December 30, 2024 with compliance required by November 1, 2027, drops the lead action level from 15 ppb to 10 ppb and requires full replacement of all lead service lines within ten years.

For Angelenos: if your home was built before 1986 (when federal law first banned lead solder and lead in new plumbing fixtures), your internal plumbing may contain lead regardless of what LADWP reports. CCR data reflects distribution system samples, not your specific tap. An inexpensive at-home lead test is the only way to know what is actually coming out of your kitchen faucet.

Hardness

Hardness averages approximately 270 mg/L as calcium carbonate, or about 16 grains per gallon, at MWD's Weymouth and Diemer treatment plants. Values across LADWP's service area range roughly 10 to 20 gpg depending on zone and season. At 16 gpg, LA water is squarely in the "very hard" category. For homes inside Santa Clarita Valley Sanitation District jurisdiction, salt-based softeners are prohibited, see our guide to the SCV salt softener ban for compliant alternatives.

What to Do With Your CCR This Year

1. Identify your source mix. San Fernando Valley north of the 118 freeway leans toward local groundwater; central and coastal LA lean toward MWD imports.
2. Check chromium-6. If your zone draws from San Fernando Basin groundwater, anything detectable above 1 ppb is worth addressing at point of use.
3. Check PFAS. Any detected PFAS above the method reporting limit is worth treating at point of use with RO.
4. Check TTHM/HAA5 locational ranges. If your local sampling point is near the MCL, whole-house catalytic carbon is a strong addition.
5. Check your home's age. If built before 1986, do an at-home lead test regardless of CCR.
6. Check hardness. If above 12 gpg and you do not have a softener, you are accumulating scale daily.

Free In-Home Water Test

A CCR gives you utility-level averages. A home water test gives you your actual tap water. Water₂O offers free on-site water testing throughout Los Angeles, Ventura, Orange, and Riverside Counties. Call (410) 262-9888 or schedule online.

Sources: LADWP 2024 Drinking Water Quality Report; California SWRCB Chromium-6 MCL rulemaking (adopted April 17, 2024); EPA PFAS NPDWR (finalized April 10, 2024, compliance extended to 2031 per May 2025 EPA announcement); EPA Lead and Copper Rule Improvements (finalized October 8, 2024); Metropolitan Water District of Southern California water quality data; Safe Drinking Water Act, 40 CFR Part 141.