Is La Mirada, CA Tap Water Safe to Drink?
Yes, La Mirada tap water is safe to drink. No contaminants exceed health guidelines. However, La Mirada has very hard water at 240 PPM, which will cause scale buildup in plumbing and appliances over time. A water softener is worth considering.
Hardness Scale: Where La Mirada Falls
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
How La Mirada Compares
La Mirada's water is 74% harder than the national average of 138 PPM. It ranks #222 out of 1000 cities in our database (harder than 78% of US cities we track). Within California, it ranks #15 of 87 cities (33% above the state average of 180 PPM). Among smaller cities, La Mirada ranks #58 of 288 for hardness. At this hardness level, water heaters run an estimated 44% less efficiently due to scale insulation, and major water-using appliances typically last 3 years less than the national average lifespan.
What La Mirada's Water Means for Your Home
Hardness: 240 PPM - Treatment Recommended
La Mirada has some seriously hard water. At 240 PPM (14 grains per gallon), your tap is loaded with dissolved calcium and magnesium picked up from underground limestone and dolomite formations. Here's the thing: it's perfectly safe to drink. The minerals won't hurt you. But they will hurt your wallet. That adds up. Hard water at 240 PPM increases household costs through scale-coated water heaters that use more energy, extra soap and detergent, and appliances that wear out faster. Most La Mirada homeowners don't realize it until the plumber shows up. That's 33% harder than the California average.
Contaminants & Safety
Disinfection byproducts are the notable finding here. La Mirada's water has TTHMs at 16.2 ppb and HAA5 at 35.6 ppb — both within legal limits, but the EWG health guidelines are far stricter. These byproducts form when chlorine reacts with organic matter during treatment. A whole-house activated carbon filter reduces both chlorine and its byproducts. Want the full picture? Request your utility's annual Consumer Confidence Report.
What's in the Treatment Process
Even though La Mirada draws from groundwater, the treatment process still generates disinfection byproducts: TTHMs at 16.2 ppb and HAA5 at 35.6 ppb. Groundwater typically needs less treatment than surface water, but when organic compounds are present in the aquifer, chlorination creates the same byproducts. All levels are within legal limits, though above the stricter EWG health guidelines.
Chromium-6 is naturally present in La Mirada's aquifer geology at 0.281 ppb — 14x the EWG health guideline. There's no federal legal limit for chromium-6 specifically (only total chromium), which is why EWG tracks it separately. All measurements are within federal legal limits. The EWG guidelines represent a more conservative, health-based standard.
How Hard Water Affects Your Home
At 240 PPM, untreated hard water has measurable effects on household costs and appliance life:
- Water heater inefficiency: Scale insulation forces the heater to work harder (DOE estimates up to 22% more energy for heavily scaled units)
- Soap and detergent: Hard water reduces lathering, requiring significantly more product
- Appliance replacement: Water heaters, dishwashers, and washing machines fail 2-4 years earlier due to scale buildup
- Plumbing maintenance: Scale buildup in pipes reduces flow and requires more frequent service
Note: Impact varies by household size, water usage, and local energy costs. A home water test provides the most accurate assessment for your specific situation.
| Contaminant | Detected | Health Guideline | Legal Limit | Status |
|---|---|---|---|---|
| Hardness (as CaCO₃) | 240 PPM | < 60 PPM | No federal limit | ⚠ Very Hard |
| Total Dissolved Solids | 380 PPM | < 300 PPM | 500 PPM | ⚠ Elevated |
| PFAS (total) | 0 ppt | — | No total limit | ✓ ND |
| ↳ PFOA | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| ↳ PFOS | 0 ppt | 0 ppt | 4 ppt (2024) | ✓ OK |
| Lead | 1.5 ppb | 0 ppb (no safe level) | 15 ppb (10 ppb in 2027) | ✓ Low |
| Chlorine / Chloramine | 1.5 mg/L | Taste threshold ~1.0 | 4.0 mg/L | ✓ Normal |
| Nitrate | 3.07 mg/L | 5 mg/L | 10 mg/L | ✓ OK |
Our Top Picks for La Mirada (240 PPM)
Hard water at 240 PPM causes scale buildup, increased energy use, and premature appliance failure. A softener protects your plumbing and appliances.
Quick Fix for Chlorine: Shower Filter
At 1.5 mg/L chlorine, many La Mirada residents notice dry skin, brittle hair, and that "pool smell" in the shower. A shower filter installs in 5 minutes, no tools needed.
How to Test Your Water in La Mirada
With 240 PPM hardness, a quick test strip confirms whether your specific tap matches La Mirada's average before you invest in a softener. Hardness can vary within the same system.
Free option: Request City of La Mirada Water's annual Consumer Confidence Report for official city-level data.
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About La Mirada's Water Supply
Water Utility: City of La Mirada Water
Water Source: Local groundwater (Groundwater)
Population Served: 49,954
Hardness: 240 PPM (14 grains per gallon)
La Mirada draws its drinking water from groundwater sources — Local groundwater. Groundwater typically requires less treatment than surface water because the earth acts as a natural filter. The tradeoff: dissolved minerals from underground rock formations, which is why hardness is elevated here. Calcium and magnesium dissolve into the water as it moves through limestone and dolomite. The system serves 50,000 residents.
Water quality can vary by neighborhood and season. For your exact numbers, request City of La Mirada Water's Consumer Confidence Report (CCR) or test your own tap.
ZIP Codes Covered by This Report
This water quality data applies to all areas served by City of La Mirada Water in La Mirada, CA, including ZIP codes:
90620, 90623, 90630, 90637, 90638, 90639, 90715, 90716, 90720, 90721, 90740, 92684
If your ZIP code is listed above, this report covers your water supply. Water quality may vary slightly by neighborhood.
Water Softener Sizing for La Mirada
At 240 PPM (14 GPG), here is how to size a softener for your La Mirada home. Multiply hardness in GPG (14) by daily water usage (roughly 50 gallons per person). A family of four uses about 200 gallons/day: 14 GPG × 200 gal = 2800 grains/day. Over a 7-day regeneration cycle, that is 19,600 grains - a 32,000-grain softener is the right fit for most La Mirada households.
Compare La Mirada to Other California Cities
Frequently Asked Questions About La Mirada Water
Is La Mirada tap water safe to drink?
Where does La Mirada's water come from?
Do I need a water softener in La Mirada?
Does La Mirada water damage tankless water heaters?
How much does hard water cost a La Mirada household per year?
What is the hardness of La Mirada water in grains per gallon?
What size water softener do I need for La Mirada?
Salt-based softener or salt-free conditioner for La Mirada?
Data sources: Lead and copper data from EPA Safe Drinking Water Act LCR reporting. Contaminant data from utility-reported testing results. PFAS data from EPA UCMR5 (2023–2025). Hardness from USGS and municipal reports. Data reflects system-level testing results and may not match your specific tap due to neighborhood plumbing, season, or recent utility changes. For your utility's latest results, request their Consumer Confidence Report (CCR). Our methodology. Last updated: 2026-02-24.
What La Mirada Homeowners Actually Buy
Common purchases for homes with 240 PPM water.
Affiliate disclosure: we may earn a commission. Selection based on La Mirada's water data.