LADWP 2025 Annual Water Quality Report Explained: What SFV Homeowners Need to Know

What is the LADWP Consumer Confidence Report and who is required to publish it?

The Consumer Confidence Report is a federally mandated annual water quality disclosure. Under the Safe Drinking Water Act and EPA Consumer Confidence Report Rule (40 CFR Part 141, Subpart V), every community water system serving 25 or more people must publish a CCR each year by July 1 and distribute it to all customers. LADWP serves roughly 3.8 million residents across Los Angeles, making it one of the largest municipal water systems in the United States.

The report covers detected contaminant levels for the previous calendar year. The 2025 CCR, published in mid-2025, covers January through December 2024. It lists every regulated contaminant LADWP tested for, the range of detected values across monitoring locations, the Maximum Contaminant Level (MCL) set by EPA or California, and whether LADWP was in compliance. A utility is in compliance if no detected level exceeded the MCL at any required monitoring point. You can download the full report from ladwp.com/water-quality. For context on how the CCR compares to what you might find at your specific tap, see our earlier guide on SFV tap water quality by source.

Where does LADWP water in the San Fernando Valley come from?

LADWP delivers water to the SFV from three source categories, blended at treatment plants before distribution:

• Colorado River Aqueduct (CRA). Purchased from the Metropolitan Water District of Southern California. Colorado River water is very hard, typically carrying 240 to 330 mg/L of dissolved calcium and magnesium as CaCO3 (roughly 14 to 19 grains per gallon). For more on what hardness means for SFV homes, see our guide on LADWP hard water in Woodland Hills.
• State Water Project (SWP). Also purchased through MWD. Sacramento Delta water is substantially softer than Colorado River water, typically 50 to 140 mg/L as CaCO3 (roughly 3 to 8 GPG). The SWP-to-CRA blend ratio shifts seasonally based on snowpack, storage, and MWD allocation decisions.
• Local San Fernando Valley groundwater. LADWP operates wells drawing from the SFV Basin aquifer under court adjudication. Local groundwater supplements the imported supply. The SFV aquifer has a distinct contaminant profile from the imported sources, including historically elevated nitrate, radionuclides, and volatile organic compounds from former industrial sites in the western Valley. LADWP blends and treats this water before it enters the distribution system.

The seasonal blend determines not just hardness but the specific contaminant mix your water carries on any given day. The CCR annual figures represent averages across all monitoring points and all source blends throughout 2024.

What contaminants does the LADWP 2025 CCR report for the San Fernando Valley?

The CCR groups contaminants by regulatory category. The categories most relevant to SFV homeowners are disinfection byproducts, inorganic chemicals, and radionuclides. Each category is explained below with the EPA MCL for reference. For specific detected ranges in 2024, download the full LADWP CCR at ladwp.com/water-quality, as those figures change year to year and citing an outdated detected range is more misleading than citing none.

Disinfection byproducts: TTHMs and HAA5

LADWP uses monochloramine as its residual disinfectant, a compound of chlorine and ammonia. When chloramine reacts with naturally occurring organic matter in source water, it forms disinfection byproducts. The two regulated categories are total trihalomethanes (TTHMs, MCL of 80 micrograms per liter) and haloacetic acids (HAA5, MCL of 60 micrograms per liter). These are regulated under the EPA Stage 2 Disinfectants and Disinfection Byproducts Rule, which requires utilities to measure them as a Locational Running Annual Average at each monitoring point rather than as a single system-wide average. Our dedicated guide on TTHMs and HAA5 in SFV tap water covers the Stage 2 compliance framework in detail. For chloramine itself, see our article on chloramines in LADWP tap water.

Nitrate

The EPA MCL for nitrate is 10 milligrams per liter as nitrogen (10 mg/L as N), per 40 CFR 141.62. Nitrate in SFV water originates from two sources: agricultural runoff and fertilizer residue reaching local groundwater, and naturally occurring geological nitrate in some aquifer zones. SFV groundwater wells have historically shown elevated nitrate compared to the imported surface water. When LADWP blends local groundwater with imported sources, the nitrate concentration in the distribution system is diluted. The CCR reports the detected range for each monitoring location, not a single system-wide number. Our dedicated guide on nitrate in SFV tap water covers the health basis for the MCL and treatment options.

Lead and copper

Lead and copper are regulated under the EPA Lead and Copper Rule, which sets action levels rather than MCLs. The lead action level is 15 micrograms per liter (15 ppb) and the copper action level is 1.3 mg/L, per 40 CFR 141 Subpart I. An action level exceedance triggers additional regulatory steps, including public notification and corrosion control treatment evaluation, but an action level is not the same as an MCL: it is the level above which LADWP must take action.

LADWP distribution mains do not use lead pipe. Lead risk in SFV homes is primarily in the internal plumbing: solder from before the 1986 federal ban on lead solder, and older fixtures installed before California AB 1953 took effect in 2010. The water LADWP delivers at the meter may be lead-free while the water at the kitchen tap reflects what the home's own pipes contribute. For more detail, see our guide on lead and copper in SFV tap water.

Arsenic

The EPA MCL for arsenic is 10 micrograms per liter (10 ppb), effective January 2006 under 40 CFR 141.62. California enforces the same 10 ppb standard. Arsenic in SFV water comes primarily from geological weathering of arsenic-bearing minerals in aquifer formations. As with nitrate, LADWP's blending of local groundwater with imported sources dilutes arsenic concentrations at distribution system monitoring points. The 2025 CCR reports the detected range for arsenic across all monitoring locations for 2024. See our dedicated guide on arsenic in SFV tap water for the regulatory history and verified treatment options.

Chromium-6 (hexavalent chromium)

California adopted a Maximum Contaminant Level of 10 parts per billion for hexavalent chromium (Cr(VI)) through a rulemaking process tied to Senate Bill 1060 (2014), which is ten times stricter than the federal 100 ppb total chromium limit under 40 CFR 141.61. LADWP monitors Cr(VI) at distribution system points and reports the detected range in its annual CCR. The western San Fernando Valley has a documented industrial history involving chromium use, and SFV groundwater wells have been tested for Cr(VI) contamination from legacy manufacturing sites. Our guide on Canoga Park water quality and chromium-6 covers the industrial history and the implications for homeowners choosing a filtration system.

Uranium and gross alpha radioactivity

The EPA MCL for uranium is 30 micrograms per liter (30 ppb) and for gross alpha particle activity is 15 picocuries per liter (15 pCi/L), both effective December 2003 under 40 CFR 141.66. California has not adopted a stricter state MCL for uranium. Uranium and gross alpha radioactivity occur naturally in some SFV aquifer zones and can also enter groundwater through geological contact with uranium-bearing rock formations. LADWP's blending process dilutes local groundwater radionuclide concentrations in the distribution system. For a full treatment of the regulatory framework and SFV data, see our guide on uranium and gross alpha in SFV tap water. For context on related radionuclides, see our article on radium in SFV tap water.

How does LADWP treat water before it reaches your tap?

LADWP applies a conventional surface water treatment train to imported water before distribution. The main treatment steps are:

• Coagulation and flocculation. Chemical coagulants cause fine suspended particles to clump together (floc) for removal. This step reduces turbidity and removes sediment, algae, and some organic material.
• Sedimentation. Floc settles out under gravity in large sedimentation basins, removing the bulk of suspended solids before filtration.
• Filtration. Water passes through granular media filters that remove remaining suspended particles, including some pathogens and organic material. This is a physical removal step, not a chemical one.
• Chloramination. LADWP switched from free chlorine to monochloramine as its primary residual disinfectant in 2014. Chloramine is more stable than free chlorine in long distribution pipe runs and generates lower levels of regulated disinfection byproducts. The EPA maximum residual disinfectant level (MRDL) for chloramine is 4.0 mg/L as Cl2.
• Fluoridation. LADWP adds fluoride to meet the EPA secondary maximum contaminant level recommendation of 2.0 mg/L. California recommends 0.7 mg/L for dental health, per the current U.S. Public Health Service standard (80 FR 1178, January 7, 2015).
• pH adjustment. LADWP adjusts pH to reduce pipe corrosion and maintain distribution system integrity. Corrosion control is particularly important for limiting lead and copper leaching from older in-home plumbing, as required under the Lead and Copper Rule.

Local SFV groundwater that LADWP draws from its wells may receive additional treatment, including aeration to remove volatile organic compounds, before blending with imported surface water. The specific treatment steps applied at each wellhead facility are documented in LADWP operational reports.

How hard is LADWP water in the San Fernando Valley, and why does it matter?

Hardness is not a regulated contaminant under federal drinking water law. It has no MCL. LADWP reports system-wide hardness in the CCR as an informational item because hardness directly affects household plumbing and appliances. Calcium and magnesium dissolved in water precipitate as calcium carbonate scale when water is heated, coating water heater elements, reducing tankless heater flow rates, and building up on dishwasher spray arms, showerheads, and faucet aerators.

The SFV blended system varies substantially across seasons. When LADWP draws a higher proportion from the Colorado River Aqueduct (typically in winter when Sierra Nevada snowpack limits State Water Project deliveries), the blended hardness in the SFV distribution system is measurably higher than the annual CCR average. The CCR annual figure smooths over those peaks. Appliances and water heaters experience every hard week of the harder months, not just the annual average.

The USGS Water Science School classifies water above 10.5 grains per gallon as very hard. Our guide on LADWP hard water in Woodland Hills explains how to read the CCR hardness table and what the numbers mean for softener or descaler decisions. For a side-by-side comparison of treatment options, see our guide on water softeners vs. salt-free descalers in the SFV.

What does a home filter add beyond what LADWP already treats?

LADWP delivers water that meets all federal MCLs at the point of entry to the distribution system. Compliance means no detected contaminant exceeded its MCL at distribution monitoring points during 2024. What a home filter adds depends on which contaminants a homeowner wants reduced beyond MCL compliance levels, and whether there are in-home plumbing contributions (particularly lead) that LADWP cannot control.

The three main home treatment technologies and what they each address:

Point-of-use reverse osmosis (NSF/ANSI 58)

An NSF/ANSI 58-certified RO system installed under the kitchen sink removes or significantly reduces: TTHMs, HAA5, nitrate, arsenic, chromium-6, uranium, lead, fluoride, and most dissolved solids. RO works by forcing water through a semipermeable membrane that rejects dissolved ions. Because the membrane rejects ions based on molecular size and charge, it addresses a broad spectrum of the contaminants the CCR reports. Certification under NSF/ANSI 58 means the system has been independently tested against the specific contaminants listed in its performance data sheet.

RO treats drinking and cooking water at a single faucet. It does not address water hardness or chloramine for showers, appliances, or the rest of the house. For guidance on comparing RO to whole-house options, see our guide on reverse osmosis vs. whole-house filtration in the SFV. For filter certification standards, see our guide on NSF 42 vs. NSF 53 vs. NSF 58 water filter certifications.

Whole-house catalytic carbon filtration (NSF/ANSI 42)

Standard activated carbon block filters are effective for free chlorine removal and taste and odor improvement, but they remove chloramine slowly and incompletely. LADWP uses chloramine, not free chlorine. Catalytic carbon is a modified form of activated carbon with enhanced surface reactivity that breaks down chloramine more effectively. A whole-house system with a catalytic carbon stage treats water at the supply line, removing chloramine taste and odor at every fixture in the home.

Whole-house carbon does not address water hardness, and it does not reduce the dissolved contaminants (nitrate, arsenic, heavy metals) that a membrane-based treatment addresses. Our guide on chloramines in LADWP tap water explains how to select the right carbon media for chloramine reduction.

Water softeners and descalers (NSF/ANSI 44 / NSF/ANSI 61)

A salt-based ion exchange water softener certified under NSF/ANSI 44 replaces calcium and magnesium ions with sodium ions, reducing hardness to a configurable target level. This prevents scale buildup in water heaters, on fixtures, and in appliance spray arms. A salt-free descaler uses a different mechanism (template-assisted crystallization or similar physical process) to change the form of calcium so it is less likely to deposit as scale, without removing it from the water.

California AB 1366 authorizes water districts to restrict brine discharge from salt-based softeners in areas with water recycling programs. Check whether this applies in your city before choosing a salt-based system. Our guide on salt-based softeners vs. salt-free descalers in the SFV covers the NSF certification data and California restriction landscape in detail.

What about PFAS, perchlorate, and other emerging contaminants in the SFV?

The 2025 CCR also covers emerging contaminants subject to newer regulatory action. PFAS (per- and polyfluoroalkyl substances) became federally regulated for the first time under the EPA final PFAS MCL rule of April 2024, with compliance required by 2029. California had already adopted health advisory levels for PFOA and PFOS before the federal rule. LADWP is required to test for PFAS and report results in future CCRs. Our guide on PFAS in SFV drinking water covers the 2024 federal rule and its timeline.

Perchlorate is another contaminant with particular relevance to the western SFV. California adopted a 1 ppb MCL for perchlorate, far stricter than the 2024 federal EPA limit of 18 ppb. The SFV has documented perchlorate groundwater contamination linked to aerospace and defense manufacturing operations at former industrial sites in Canoga Park and the Santa Susana Field Laboratory area. LADWP monitors and treats local groundwater for perchlorate before distribution. Our guide on perchlorate in SFV tap water covers the regulatory record and treatment options. For additional context on industrial-era contaminants, see our article on manganese in SFV tap water.

How do I get a free water test for my SFV home?

The LADWP CCR is the starting point for understanding what the utility delivers at the distribution system level. It does not tell you what comes out of your specific faucet, because in-home plumbing between the meter and the tap can add lead, iron, and other contaminants that LADWP cannot control. An in-home water test covers hardness (in GPG and mg/L as CaCO3), total dissolved solids (TDS in mg/L), pH, and chloramine or chlorine residual, measured at your tap rather than at a distribution monitoring point. Those results give you the inputs for sizing the right treatment system.

The San Fernando Valley water filtration system we recommend follows from what the tap test shows. For dissolved-contaminant concerns (arsenic, nitrate, lead, chromium-6), the key input is a TDS reading and, ideally, a certified lab test for the specific contaminant. Field test kits measure hardness and chloramine reliably but are not certified laboratory analyses for regulatory or legal disclosure purposes. Our water quality services cover Woodland Hills, West Hills, Canoga Park, Calabasas, Winnetka, Westlake Village, Reseda, Northridge, Tarzana, Encino, Chatsworth, and Agoura Hills.

Sources used in this article: LADWP 2025 Consumer Confidence Report (2024 data); EPA National Primary Drinking Water Regulations; EPA Stage 2 Disinfectants and Disinfection Byproducts Rule; EPA Radionuclides in Drinking Water; USGS Water Science School: Hardness of Water; EPA Consumer Confidence Report Rule.