On August 16, 1933, something went wrong at the Chicago World's Fair that had nothing to do with the rides, the exhibits, or the crowds pouring through the gates. It had to do with plumbing. Defective cross-connections in the fairground's water system let contaminated water flow backward into the drinking supply. By the time health officials figured out what was happening, 1,409 people had contracted amebic dysentery. Ninety-eight of them died.

I've been a plumber in the Central Valley for more than 30 years, and I still think about that number every time I install a backflow preventer. Ninety-eight people went to a fair and didn't come home because nobody had engineered a reliable way to stop dirty water from flowing the wrong direction through a pipe. That single event is why August 16 is now recognized every year as National Backflow Prevention Day, and it's why an entire branch of the plumbing trade exists today. Backflow prevention isn't a code requirement somebody dreamed up to make our jobs harder. It's a public health system that was built, quite literally, on top of a tragedy.

Four companies answered that call more than any others. Over the next century, they turned a niche safety problem into a mature, engineered discipline — and in the process, they built the valves that sit in vaults and enclosures on practically every commercial property, apartment complex, and irrigated front lawn in Fresno County. I've installed, repaired, and tested all four of these brands more times than I can count. This is my case for why they belong on the Backflow Mount Rushmore, carved in bronze and stainless steel, right alongside the other founding fathers of American infrastructure.

What Is Backflow, Anyway?

Before I get to the four faces on the mountain, let's back up for the homeowners reading this who've never had a reason to think about backflow before today.

Your water system is designed to push clean, pressurized water in one direction — from the municipal main, through the meter, into your house or your irrigation system. Backflow is what happens when that pressure reverses and water starts flowing the wrong way. It usually happens because of a sudden drop in supply pressure — a water main break, a fire hydrant in heavy use nearby, even routine maintenance work upstream. When that pressure drop happens and your irrigation system, pool, or plumbing is cross-connected to the potable water supply without protection, whatever is sitting in that system — fertilizer, pesticide residue, standing water, even sewage in worst-case scenarios — can get siphoned backward into the clean water line. From there, it can end up in your kitchen faucet.

A backflow preventer is a mechanical device, usually installed where a property's plumbing connects to the municipal supply or where an irrigation system branches off, that physically stops that reverse flow. Some use check valves. Others use air gaps and relief valves. The engineering differs by device type, but the mission is identical: keep the dirty water on its side of the line, no matter what happens to the pressure.

That's a simple concept. Building a device that does it reliably, year after year, under real-world conditions with hard water, agricultural chemicals, and temperature swings — that's where these four manufacturers made their names.

Why a Mount Rushmore?

I'll be honest, I've had this argument with other plumbers over coffee more times than I can count. Everybody's got an opinion about which backflow brand is best, which one fails less, which one the inspectors trust. But when you step back from brand loyalty and look at actual industry history — who invented the categories, who built the factories, who trained a generation of engineers to spec their products by name — four companies stand so far above the rest that there's no real argument left to have. They didn't just compete in this industry. They built it, brick by brick, valve by valve, going back over a century.

Three of the four were born in California. One of them practically invented the residential relief valve that's sitting on your water heater right now. All four still show up on job sites across Fresno County every single week. That's not nostalgia — that's a track record.

The Four Faces

1. Ames — The Commercial and Fire-Line King

Ames got its start in 1910 as Ames Fire & Waterworks in Woodland, California — a Central Valley company almost from day one, making valves and fittings for fire protection, waterworks, and irrigation systems at a time when most of that infrastructure was still being invented as it went along. Over the following decades, Ames became the name engineers reached for when they needed large-bore backflow protection for commercial buildings and fire suppression systems. Their 2000B double check valve and 4000SS stainless steel series are still specified independently by name on commercial and fire-line projects, which in an industry full of interchangeable parts, means something.

In 1997, Watts acquired Ames for roughly $27 million, folding the two biggest names in commercial backflow prevention under one corporate roof. But here's the thing — Ames kept its identity. Engineers still spec "Ames" on drawings. Inspectors still know the name. Ames earns its place on the mountain because for decades it owned the commercial and fire protection segment of this industry outright, and its Woodland, California roots make it about as Central Valley as a backflow preventer manufacturer gets.

2. Watts Regulator — The Company That Wouldn’t Stop Building

Watts is the granddaddy of this entire industry, and its story starts nowhere near a backflow valve. In 1874, an English immigrant machinist named Joseph E. Watts founded Watts Regulator in Lawrence, Massachusetts, building pressure regulators that kept textile mill boilers from exploding and killing the workers standing next to them. That's not an exaggeration for effect — steam boiler explosions were a real and common danger in 19th-century factories, and Watts's early regulators saved lives before the company ever touched a water pipe.

In the early 1900s, Watts introduced the temperature and pressure relief valve — the T&P valve — which is still a required safety component on every residential water heater installed today. If you've ever wondered what that little lever and pipe sticking out of the side of your water heater is for, that's a Watts invention doing its job, decade after decade, on essentially every water heater in America.

Watts didn't get into backflow prevention until the 1970s, and the story behind it is one of my favorites in the trade. Colorado state sanitation inspectors, wrestling with early cross-connection contamination problems, came directly to Watts looking for a solution. Watts developed the Model 900 reduced pressure zone (RPZ) valve within a year. That kind of responsiveness — go from "we have a public health problem" to "here's a manufactured solution" in twelve months — tells you everything about why Watts became the dominant name in residential and light commercial backflow prevention. The Watts 007 series RPZ remains one of the most widely installed reduced pressure zone devices in the country, and if you've ever bought a backflow preventer off the shelf at a plumbing supply house, odds are good it had the Watts name stamped on it. Watts earns its spot on the mountain because no other manufacturer has done more, at more levels of the industry, for more decades, than this one.

3. Wilkins — The California Original

If Ames and Watts represent the commercial and residential supply-house sides of this industry, Wilkins is the brand that feels like it was built specifically for California. James Wilkins started the company in 1906 out of a 200-square-foot garage in Los Angeles. Four years later, in 1910 — the same year Ames was founded up in Woodland — Wilkins released its first backflow prevention device. From a garage to a 163,000-square-foot manufacturing facility in Paso Robles, just up the road from the Central Valley, Wilkins grew right alongside California's water infrastructure needs.

Zurn Industries acquired Wilkins in 1972, and the corporate lineage since then reads like a chain of custody report — Zurn Industries, acquired by Jacuzzi Brands in 1998, acquired by Rexnord in 2007, eventually becoming Zurn Water Solutions and then merging with Elkay Manufacturing to form what's now Zurn Elkay Water Solutions. Zurn itself dates back to 1900 in Erie, Pennsylvania, when John A. Zurn patented a backwater valve of his own, which means the Wilkins name now sits inside a lineage with two separate century-old founding stories running through it.

On the job, the 975XL RPZ and the 350 DCVA (double check valve assembly) are bread-and-butter installs for California plumbers, myself included. Wilkins earns its spot on the mountain because it is, in every meaningful sense, the California plumber's brand — born in an L.A. garage, built for the West Coast market, and still dominating residential and irrigation installs more than 115 years later.

4. Febco — The Irrigation Standard

Febco doesn't have the same sprawling corporate acquisition story as the others, but it doesn't need one, because Febco did something no other manufacturer on this list managed to do as thoroughly: it owns an entire device category. Febco pioneered the pressure vacuum breaker, or PVB, and its Febco 765 PVB is, without exaggeration, the single most installed backflow device on residential irrigation systems anywhere in California. If you've got a sprinkler system in your front yard here in Fresno, I'd put money on there being a Febco 765 sitting in a valve box or mounted on a riser somewhere on your property right now.

Febco is now part of Aalberts Industries, a Dutch industrial conglomerate, through its Climate & Fluid Control division, and Watts distributes Febco products throughout North America — so these two brands on our mountain are more intertwined than most homeowners realize. But the Febco name stands on its own merit. It earns its spot on the mountain because nothing else comes close to its dominance of California residential irrigation backflow prevention west of the Rockies. That's not a close contest. That's a category owned outright.

The Honorable Mentions

No Mount Rushmore argument is complete without acknowledging the names that didn't quite make the carving but still matter on real job sites. Conbraco/Apollo has built a solid reputation in commercial and industrial backflow assemblies and shows up regularly on larger properties. Mueller has a long history in water infrastructure broadly, including valves that touch the backflow world, going back to the same era that produced our four founders. Cash Acme has carved out its own space in relief valves and smaller residential backflow components. All three are legitimate manufacturers that any working plumber respects. They just don't have the century-plus histories, the category-defining products, or the sheer market presence that Ames, Watts, Wilkins, and Febco have built. That's not a knock — that's just what it takes to get carved into a mountain.

Why This Matters for Fresno Homeowners

Here's where the history lesson turns practical. California has some of the strictest cross-connection control regulations in the entire country, codified under Title 17 of the California Code of Regulations, Sections 7583 through 7622. These aren't suggestions. They're enforceable standards that determine what kind of backflow device has to be installed at what kind of connection, and how often that device has to be tested to make sure it's still doing its job.

The Central Valley has a wrinkle that a lot of homeowners don't think about until it's explained to them: this region runs on some of the most extensive agricultural irrigation infrastructure in the country, and that infrastructure sits right alongside residential and municipal water systems. Ag irrigation lines, residential sprinkler systems, and the drinking water supply all exist in close proximity out here in a way that creates real cross-connection risk if the right devices aren't in place and properly maintained. That's not fear-mongering — that's the exact scenario backflow prevention was engineered to solve, and it's a bigger deal in Fresno County than it is in a lot of other parts of the state.

It's also worth noting that three of our four Mount Rushmore brands — Ames, Wilkins, and Febco — have deep California roots. This isn't an industry that was imposed on us from somewhere else. A meaningful piece of backflow prevention history was built right here in this state, by companies solving California water problems for California properties.

In my 30-plus years installing backflow preventers across the Central Valley, I've worked with all four of these brands on everything from small residential irrigation systems to large commercial fire-line assemblies. Each one earned its reputation the hard way — by making a device that held up, year after year, on real properties under real conditions. That's the kind of track record that matters when it's your family's drinking water on the other side of that valve.

Stedman’s Plumbing Handles Backflow, Start to Finish

Whether you've got a Watts RPZ protecting your commercial building, a Febco 765 sitting in your front yard irrigation system, a Wilkins assembly on a multi-family property, or an Ames device on a fire line, Stedman's Plumbing installs, tests, and repairs backflow prevention devices throughout Fresno County. California requires annual testing on most backflow assemblies to stay compliant with Title 17, and we handle that certification process for homeowners, property managers, and commercial clients across the Central Valley.

If it's been a while since your backflow preventer was tested, or if you're building new and need a device installed to code, give us a call at (559) 770-9772 or reach out through our contact page. Thirty years on the job in this Valley has taught me that the plumbers who respect this history are the ones who install it right the first time.