What's Actually in La Mirada's Tap Water? The 2025 Report Has Some Answers Worth Reading

Have you ever actually looked at what's in your tap water? Not the quick glance at the annual notice that shows up in your mailbox. The real data. The lab results. The stuff that takes a little digging to find.

If you live in La Mirada and your water comes from Suburban Water Systems, their 2025 Public Health Goals Report is now public. It's the kind of document most people never read, but it contains some details that are worth your time, especially if you've been thinking about adding a water filter to your home.

Two Water Companies, Zero Municipal Control

Before getting into the report itself, here's some background that surprises a lot of La Mirada homeowners. Your city doesn't run its own water system. La Mirada is served by two private, CPUC-regulated utilities: Suburban Water Systems (part of SouthWest Water Company) and Golden State Water Company. Which one you pay depends entirely on where your house sits.

Most addresses in La Mirada fall under Suburban Water Systems. If you're closer to the eastern edge of the city, near Beach Boulevard or toward the Biola University campus, you may be in Golden State Water's Central Basin East territory. Check the name on your water bill if you're not sure.

Golden State Water is in the middle of a $33.2 million infrastructure investment across its Central Basin East service area for 2025 through 2027, with new rates that took effect in February 2025. That's a big spend, and La Mirada customers in that zone will see some of it reflected in their bills.

So What Did the 2025 Report Actually Find?

Suburban Water Systems collects roughly 9,000 water samples every year. That's a lot of testing. The 2025 report flags two contaminants that exceeded California's Public Health Goals but remained within the Maximum Contaminant Levels (the enforceable legal limits).

The first is hexavalent chromium, sometimes called chromium-6. If that name sounds familiar, it's the same chemical from the Erin Brockovich case in Hinkley, California. In La Mirada's case, the hexavalent chromium is naturally occurring. It leaches from local geology into groundwater. It's not the result of industrial dumping or a spill.

The second is perchlorate, which is a different story. The perchlorate traces in La Mirada's supply come from imported water originating near Whittier-area sources with a history of industrial contamination. Perchlorate is a component of rocket fuel and certain fertilizers, and it can interfere with thyroid function at high concentrations.

Both contaminants were detected below the Maximum Contaminant Level, which means the water is legally compliant and considered safe by regulatory standards. But California's Public Health Goals are set lower than the MCLs. They represent the concentration at which no known health effects would be expected over a lifetime of drinking the water. Think of the PHG as the ideal target and the MCL as the legal ceiling.

What's the Difference Between a PHG and an MCL?

This is where it gets practical for homeowners. The MCL is enforceable. If a water company exceeds it, they have to take corrective action. The PHG is aspirational. It's based purely on health science without considering cost or technical feasibility of treatment.

When a contaminant falls between the PHG and the MCL, as hexavalent chromium and perchlorate do in La Mirada's supply, your water is legal and meets all regulatory requirements. But the report is telling you there's a gap between what's technically safe and what's ideally clean.

For most healthy adults, that gap probably doesn't warrant losing sleep. But if you have young kids, a family member with thyroid issues, or someone who is immunocompromised in the house, it's reasonable to want to close that gap on your own.

When a Whole-House Filter Actually Makes Sense

Not every home needs a whole-house filtration system. They cost anywhere from $1,500 to $5,000 installed, plus annual filter replacements. For a lot of La Mirada households, a certified point-of-use water filter at the kitchen sink handles drinking and cooking water at a fraction of the cost.

But there are situations where a whole-house system earns its price tag:

Your home has older galvanized steel pipes. Many houses in La Mirada built in the 1950s and 1960s, especially in the older neighborhoods between Rosecrans Avenue and the La Mirada Golf Course, still have original galvanized supply lines. These pipes corrode from the inside out and can add their own metals to the water. A whole-house filter with a sediment stage helps reduce what's coming from both the utility supply and your own aging pipes. You have a tankless water heater. Tankless units are sensitive to sediment and mineral buildup. If your water has even moderate hardness (common in this part of LA County), a whole-house system with a water softener component protects the heat exchanger and extends the unit's life. Multiple family members have skin sensitivity. Chloramine, which is the disinfectant used in La Mirada's water supply, can aggravate eczema and dry skin conditions. A whole-house carbon filter removes chloramine from every tap and shower in the house.

If none of those apply, a good under-sink reverse osmosis system certified to NSF/ANSI Standard 58 will handle hexavalent chromium and perchlorate for your drinking water. You can find certified models through the NSF International product database.

Don't Forget What's Underground

Water quality is one part of the picture. The pipes carrying that water through your neighborhood are another.

La Mirada's sewer system includes 120 miles of gravity sewer lines and 4 pump stations, all maintained through a contract with LA County. That's the public side. Your sewer lateral, the pipe connecting your house to the city main, is on you.

If your home is near Neff Park or in the original La Mirada tract developments from the late 1950s, your sewer lateral could be 65-plus years old. Clay pipe was standard back then, and tree roots love clay joints. A sewer camera inspection costs a couple hundred dollars and can tell you whether you're five years or five months from a backup into your garage.

The city is also working through a Housing Element update for 2021-2029 that includes rezoning for additional residential density. More homes on the same sewer and water infrastructure means more demand on systems that were designed for a smaller population. That's not a crisis, but it's context worth having if you're planning renovations or evaluating the long-term condition of your property's plumbing.

The Bottom Line for La Mirada Homeowners

Your tap water meets every legal standard. The utilities serving La Mirada test extensively and report transparently. But "meets legal limits" and "nothing to think about" aren't the same thing. Read the report, understand what's in your water, and decide whether the gap between the PHG and MCL matters for your household.

If it does, a certified filter is a straightforward fix. If it doesn't, at least now you know what you're drinking.

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Looking for plumbing info in nearby cities? Check out our guides for Norwalk, Whittier, and Cerritos.

Frequently Asked Questions

Is La Mirada's tap water safe to drink?

Yes. Both Suburban Water Systems and Golden State Water Company meet all federal and state maximum contaminant level requirements. The 2025 Public Health Goals Report did identify hexavalent chromium and perchlorate in some samples, but concentrations fall within legally allowable limits. If you want extra peace of mind, a certified point-of-use filter can reduce these contaminants further.

Who provides water service in La Mirada?

La Mirada is split between two private, CPUC-regulated water providers. Suburban Water Systems (a SouthWest Water Company subsidiary) covers most of the city. Golden State Water Company serves portions of La Mirada through its Central Basin East service area. Your provider depends on your street address, so check your water bill if you're unsure.

Who handles sewer maintenance in La Mirada?

The City of La Mirada contracts with Los Angeles County for sewer maintenance across its 120 miles of gravity sewer lines and 4 pump stations. Wastewater discharges to the Sanitation Districts of LA County for treatment. However, the sewer lateral connecting the public main to your house is typically the homeowner's responsibility to maintain and repair.