From PFAS Crisis to the Nation's Largest Treatment Plant: Yorba Linda's Water Story and What Homeowners Should Still Check

In February 2020, the Yorba Linda Water District did something no water agency wants to do. They shut down all 10 of their groundwater wells. Every single one. PFAS contamination had shown up at levels the district wasn't comfortable delivering to the 80,000 customers who depended on that water.

For a community that gets most of its supply from local groundwater, that was a serious moment.

What happened next, though, turned Yorba Linda into a national example of how to respond. And it happened fast.

Building the Biggest PFAS Plant in the Country

By December 2021, less than two years after the shutdown, the J. Wayne Miller PFAS Treatment Plant was operational. It's not just big. It's the largest ion exchange PFAS treatment facility in the United States.

The numbers are staggering. Six pre-filter units. Twenty-two ion exchange vessels. A 25-million-gallon-per-day booster station. All of it designed to strip PFAS compounds from groundwater before a single drop reaches your faucet.

Every one of those 10 wells now runs through the treatment plant. The water is clean. And YLWD has been expanding capacity since, including securing $1.105 million in federal funding for Well 23, which will become the district's 11th groundwater well. Congresswoman Young Kim helped push that through the FY 2026 Energy and Water bill, signed in January 2026.

So the supply side of things? Handled.

The Part That's Not the District's Job

Here's where homeowners need to pay attention. YLWD treats the water. YLWD maintains the mains and the infrastructure on their side of the meter. But everything from the meter to your kitchen sink belongs to you.

And if you live in Bryant Ranch or one of the other neighborhoods built in the 1960s and 1970s, your interior plumbing is now 50 to 60 years old. Copper lines from that era are often still in decent shape, but the joints, valves, shut-offs, and fixtures? Those wear out. Galvanized sections that were common in mixed-material installations are likely corroded.

You can have the cleanest water in Southern California flowing through your street. If your home's pipes are deteriorating, what comes out of your tap tells a different story.

56,000 Aging Assets and a Rate Study

YLWD isn't just thinking about water quality. They're staring down an infrastructure problem familiar to every aging utility district in California.

The 2026 Rate Study identifies 56,000 district-owned assets that need repair or replacement. A public hearing is scheduled for April 9, 2026 at YLWD headquarters. If approved, the first rate adjustment hits July 1, 2026, with annual increases through 2031.

Nobody cheers for higher water bills. But when a district has already proven it will spend money wisely (see: building the nation's top PFAS facility in under two years), there's at least a track record of follow-through.

The Timber Ridge Booster Pump Station upgrade completed in August 2025 is another example. Quiet, necessary work that keeps pressure consistent in the hillside neighborhoods near Chino Hills State Park.

Fix a Leak Week Was Trying to Tell You Something

Every March, YLWD runs Fix a Leak Week. This year's edition, March 16 through 22, offered free toilet dye tablets at 1717 E. Miraloma Ave in Placentia with a lobby display on finding household leaks.

Sounds small. But the EPA estimates that household leaks waste roughly one trillion gallons of water nationally each year. A running toilet can waste 200 gallons a day without making enough noise for you to notice. A slow leak under a slab can go undetected for months.

Did you pick up those dye tablets? If not, you can buy them at any hardware store for a couple of dollars. Drop one in the toilet tank, wait 15 minutes, and check the bowl. If there's color, your flapper valve is leaking. It's a $5 fix that can save you $50 a month on your water bill.

New Construction vs. Established Neighborhoods

Yorba Linda is still growing. City Ventures has 62 townhomes pending, and the Altrudy II senior housing project at 18611 Altrudy Lane will add 64 units when it wraps up around 2027 or 2028. All new construction, all modern plumbing.

But the bulk of Yorba Linda's residential base is established. The neighborhoods along Imperial Highway, the homes backing up to Carbon Canyon Regional Park, the streets around the Richard Nixon Presidential Library on Yorba Linda Boulevard. These were built in waves from the 1960s through the 1990s.

Newer isn't always better maintained, of course. But a home built in 1972 with original supply lines, original hose bibs, and a water heater from 2011 deserves a professional once-over.

A Practical Homeowner Checklist

You don't need to repipe your entire house tomorrow. But a few things are worth checking this month.

Test your toilets. Dye tablets or a few drops of food coloring in the tank. Free, easy, and catches the most common household leak. Check your water pressure. Screw a gauge onto an outdoor spigot. Yorba Linda homes should read between 50 and 70 PSI. Too high and you're stressing every fixture and connection in the house. Look at your water heater's age. The serial number usually contains the manufacture date. Over 12 years old? Start budgeting for a replacement. A water heater failure in a garage is inconvenient. A water heater failure in an interior closet is a flood. Walk your yard after dry weather. Soggy spots when it hasn't rained could mean a leaking supply line or sewer lateral underground.

YLWD solved the big problem. They took contaminated wells, built the largest treatment plant of its kind, and got clean water flowing again. That's the hard part done.

The easy part, relatively speaking, is making sure your own plumbing isn't undoing their work. Worth a Saturday morning to find out.

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Looking for plumbing info in nearby cities? Check out our guides for Anaheim, Placentia, and Brea.

Frequently Asked Questions

Q: Is Yorba Linda water safe to drink now?

A: Yes. After shutting down all 10 groundwater wells in 2020 due to PFAS contamination, the Yorba Linda Water District built the J. Wayne Miller PFAS Treatment Plant, the largest ion exchange facility in the country. All groundwater now runs through 22 ion exchange vessels before reaching your tap, and the water meets every state and federal standard.

Q: Are YLWD water rates changing in 2026?

A: YLWD is conducting a 2026 Rate Study with a public hearing set for April 9, 2026. The district has 56,000 aging assets that need attention, and if approved, the first rate adjustment would start July 1, 2026, with annual increases through 2031.

Q: How do I check for leaks in my Yorba Linda home?

A: Start with your toilets. Drop a dye tablet or food coloring in the tank, wait 15 minutes without flushing, and check if color shows in the bowl. Then look at your water meter with all fixtures turned off. If the dial is still moving, you've got a leak somewhere in the system. YLWD offers free dye tablets at their office at 1717 E. Miraloma Ave in Placentia.