Your Local Water Profile: Malibu
This profile explains what the applicable water provider reported for Malibu, what those results may mean throughout a home, and where property-specific testing or inspection may still be needed.
Water provider: Los Angeles County Waterworks Districts
Public water system CA1910204 · 2025 report · Current 2025 monitoring cycle
View the 2025 Los Angeles County Waterworks Districts Consumer Confidence ReportWhat the official water report says
Your water at a glance
Los Angeles County Waterworks District 29
The report lists hardness as 234 ppm; this is very hard on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
Los Angeles County Waterworks Districts — compliance, as reported
The report states: “We are proud to report that in 2025, your water met or surpassed all health-based drinking water standards. [p. 1]”
The Three C's — 1 of 3
Chemistry
What does this water tend to do in a home?
Alkalinity, Total as CaCO3
The utility reported: 110 ppm
OTHER PARAMETERS · report p. 4 · official report
Alkalinity, Total as CaCO3
The utility reported: 98 ppm
OTHER PARAMETERS · report p. 4 · official report
Hardness, Total as CaCO3
The utility reported: 234 ppm
OTHER PARAMETERS · report p. 4 · official report
Hardness, Total as CaCO3
The utility reported: 140 ppm
OTHER PARAMETERS · report p. 4 · official report
Chloride
The utility reported: 92 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Chloride
The utility reported: 49 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Sulfate
The utility reported: 176 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Sulfate
The utility reported: 71 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Total Dissolved Solids
The utility reported: 536 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Total Dissolved Solids
The utility reported: 297 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
The Three C's — 2 of 3
Contaminants
What was reported, and what do the applicable standards mean?
Legal limit — maximum contaminant level (MCL)
The highest level legally allowed in public drinking water under the applicable rule. Do not use MCL as a generic label for goals, action levels, notification levels, or independent guidelines. It is different from a non-enforceable health goal.
California health goal — public health goal (PHG)
A non-enforceable health-protective target developed for standard-setting context. It is not the California legal limit.
Federal health goal — maximum contaminant level goal (MCLG)
A non-enforceable EPA public-health target used in setting standards. It is not the legal limit.
Legal disinfectant-residual limit — maximum residual disinfectant level (MRDL)
The highest level of a drinking-water disinfectant allowed under the applicable rule. It is not an MCL for a contaminant.
Los Angeles County Waterworks Districts — regulated contaminants reported as detected (16)
Aluminum
The utility reported: 96 ppb
Reported range: ND - 100
Legal limit (MCL): 1000 · Health goal (PHG): 600 — not an enforceable limit
Violation per report: No
Typical source, per the report: Residue from water treatment process; runoff and leaching from natural deposits
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Aluminum
The utility reported: 60 ppb
Reported range: ND - 79
Legal limit (MCL): 1000 · Health goal (PHG): 600 — not an enforceable limit
Violation per report: No
Typical source, per the report: Residue from water treatment process; runoff and leaching from natural deposits
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Chlorine**
The utility reported: 1.5 ppm
Reported range: 1.4 - 1.6
MRDL: 4.0 as Cl2 · Health goal (MRDLG): 4 as Cl2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Chlorine**
The utility reported: 2.6 ppm
Reported range: 1.1 - 3.1
MRDL: 4.0 as Cl2 · Health goal (MRDLG): 4 as Cl2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Fluoride
The utility reported: 0.7 ppm
Reported range: 0.5 - 0.8
Legal limit (MCL): 2 · Health goal (PHG): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; discharge from fertilizer and aluminum factories
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Fluoride
The utility reported: 0.7 ppm
Reported range: 0.6 - 0.8
Legal limit (MCL): 2 · Health goal (PHG): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; discharge from fertilizer and aluminum factories
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Gross Beta
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Legal limit (MCL): 50 · Health goal (MCLG): 0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of natural and man-made deposits
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Haloacetic Acids [HAA5]**
The utility reported: 5.3 ppb
Reported range: 3.8 - 5.7
Legal limit (MCL): 60
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Haloacetic Acids [HAA5]**
The utility reported: 3.1 ppb
Reported range: ND - 4.9
Legal limit (MCL): 60
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Haloacetic Acids [HAA5]**
The utility reported: 3.0 ppb
Reported range: ND - 2.9
Legal limit (MCL): 60
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Total Organic Carbon (TOC)
The utility reported: 2.5 ppm
Reported range: 1.6 - 2.8
TT: TT
Violation per report: No
Typical source, per the report: Various natural and man-made sources; TOC is a precursor for the formation of disinfection byproducts
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Total Organic Carbon (TOC)
The utility reported: 2.3 ppm
Reported range: 1.9 - 2.4
TT: TT
Violation per report: No
Typical source, per the report: Various natural and man-made sources; TOC is a precursor for the formation of disinfection byproducts
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Total Trihalomethanes [TTHMs]**
The utility reported: 19.0 ppb
Reported range: 10 - 31
Legal limit (MCL): 80
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Total Trihalomethanes [TTHMs]**
The utility reported: 31 ppb
Reported range: 24 - 30
Legal limit (MCL): 80
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Total Trihalomethanes [TTHMs]**
The utility reported: 14 ppb
Reported range: 10 - 17
Legal limit (MCL): 80
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Uranium
The utility reported: 2 pCi/L
Reported range: 2-3
Legal limit (MCL): 20 · Health goal (PHG): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
PRIMARY DRINKING WATER STANDARDS · report p. 3 · official report
Los Angeles County Waterworks Districts — unregulated monitoring and secondary (aesthetic) records (6)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Aluminum
The utility reported: 96 ppb
Reported range: ND - 100
Typical source, per the report: Erosion of natural deposits; residue from some surface water treatment processes
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Aluminum
The utility reported: 60 ppb
Reported range: ND - 79
Typical source, per the report: Erosion of natural deposits; residue from some surface water treatment processes
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Specific Conductance
The utility reported: 868 µS/cm
Reported range: 754 - 981
Typical source, per the report: Runoff/leaching from natural deposits
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Specific Conductance
The utility reported: 504 µS/cm
Reported range: 503 - 504
Typical source, per the report: Runoff/leaching from natural deposits
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Potassium
The utility reported: 4.4 ppm
Reported range: 3.8 - 5
OTHER PARAMETERS · report p. 4 · official report
Potassium
The utility reported: 2.8 ppm
Reported range: 2.8 - 2.9
OTHER PARAMETERS · report p. 4 · official report
The Three C's — 3 of 3
Corrosion
What conditions could influence pipes, fixtures, and a water heater?
Alkalinity, Total as CaCO3
The utility reported: 110 ppm
OTHER PARAMETERS · report p. 4 · official report
Alkalinity, Total as CaCO3
The utility reported: 98 ppm
OTHER PARAMETERS · report p. 4 · official report
Chloride
The utility reported: 92 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Chloride
The utility reported: 49 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Sulfate
The utility reported: 176 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Sulfate
The utility reported: 71 ppm
SECONDARY DRINKING WATER STANDARDS · report p. 4 · official report
Whole-Home Relevance
What this may mean throughout your home
Local conditions can be relevant to equipment and fixtures — actual effects depend on your property.
Water heater (tank and tankless)
- What the local report can tell us
- The report's hardness and mineral values above are the system-level inputs most relevant to scale and sediment where water is heated.
- What a homeowner may notice
- Hardness minerals can contribute to scale on heating surfaces, sediment in tanks, and more frequent flushing or descaling needs.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Dishwasher and washing machine
- What the local report can tell us
- Reported hardness and secondary (aesthetic) records are the relevant system-level context for spotting and residue.
- What a homeowner may notice
- Hard water can change soap behavior and may contribute to spotting on dishes and residue in laundry.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Pipes, fixtures, faucets, and supply lines
- What the local report can tell us
- The corrosion-related inputs above (such as pH) describe the water entering the property — not the condition of any specific plumbing.
- What a homeowner may notice
- Mineral deposits can appear on aerators and fixtures; corrosion outcomes depend on materials, age, and water conditions together.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Drinking and cooking water
- What the local report can tell us
- The contaminant records above show what the utility reported for the system and period, with each benchmark type labeled.
- What a homeowner may notice
- Taste, odor, or aesthetic preferences can be noticeable even when health-based standards are met.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Decision Pathways
Treatment pathways to evaluate
Treatment is a decision pathway, not a product conclusion — no equipment can be responsibly chosen from city-level data alone.
The evaluation sequence we follow, in order:
- 1Define the concern
- 2Verify utility-level and home-specific evidence
- 3Choose point of treatment
- 4Verify the exact certified reduction claim for the exact model
- 5Review tradeoffs and maintenance
Water filtration
- Objective it can address
- Specific substances or aesthetic conditions (taste, odor, chlorine character).
- Point of treatment
- Point of entry or point of use, depending on the objective.
- Limitations to verify
- A filter works only for the conditions and reduction claims its exact design and certification support — filtration does not soften water.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Water softening
- Objective it can address
- Hardness minerals (calcium and magnesium) and the scale they can contribute to.
- Point of treatment
- Typically point of entry, confirmed by evaluation.
- Limitations to verify
- Softening primarily exchanges hardness minerals — it is not a universal contaminant-removal device.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Reverse osmosis
- Objective it can address
- Specified dissolved substances at a dedicated outlet, commonly drinking and cooking water.
- Point of treatment
- Typically point of use.
- Limitations to verify
- Produces a reject-water stream and needs pressure and maintenance; verify the exact NSF/ANSI 58 reduction claims for the exact model. It is not automatically the best system for every home.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
When testing is the right next step
Use a certified laboratory when the concern is tap-specific, property-specific, or not resolved by the utility report.
When inspection is the right next step
Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Evidence You Can Check
Official reports, sources, and methodology
Official report — Los Angeles County Waterworks Districts
Consumer Confidence Report · data year 2025 · Current 2025 monitoring cycle
View the 2025 Los Angeles County Waterworks Districts Consumer Confidence ReportSource water, per the report: The Metropolitan Water District of Southern California (MWD) supplies the District through West Basin Municipal Water. MWD supplies water from the Colorado River Aqueduct, which travels from Lake Havasu on the California-Arizona border to Lake Mathews near Riverside. The water is transported in the State Water Project’s California Aqueduct.
Nearby community water profiles
Property-Specific Next Step
Request a Water Quality Evaluation
Request a water-heater and water-quality evaluation tailored to the property, equipment, and homeowner objective.
A property-specific evaluation confirms your goals, provider, tap conditions, plumbing, equipment, installation, and maintenance before any treatment recommendation — this profile alone is never used to prescribe equipment.

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