When you turn on the faucet  in your kitchen or bathroom, you probably expect clean water to come out.

If it does, you can thank  regulations like the Clean Water Act. This US law was introduced in 1972 to curtail water pollution across the States.

And we desperately needed it. Lakes were filling with toxic green slime, people were drowning in polluted sludge, and rivers were literally catching on fire. If that wasn’t gross enough, this polluted water was even invading homes.

Tap water was coming out… bubbly. The cause of all this pollution  was the last thing you’d expect to make things dirtier: Laundry detergent  that was way too good at its job. [♪INTRO] In the 1940s, laundry machines were spreading to households across the United States. The appliances promised to  free up hours, or even days, that people used to spend  scrubbing clothes by hand.

And that is so worth it, in my opinion. I mean, I have a washing machine and I still think laundry takes too long. But for all the time they saved,  those early washing machines weren’t quite as dirt-busting as  good old-fashioned hand washing.

For one thing, the washing machines  just didn’t scrub hard enough. And soap needs to get to  the dirt in order to work. Each soap molecule has a hydrophilic  end that binds well to water and a hydrophobic end that  avoids water at all costs.

The hydrophobic end, however,  does stick well to grease and dirt and all the gross stuff  we want to wash out of our clothes. So the hydrophobic ends  encapsulate the dirt and grime, leaving the hydrophilic ends sticking out. Then, when you rinse your  clothes, the hydrophilic ends of the soap blob stick to the rinse  water and carry the dirt away.

For the deepest clean, the soap needs to get all up in the fibers,  and also get back out again. And washing machines of the  1940s didn’t have the mechanical power to do that as well as  a human with a washboard. The second problem was hard water.

Hard water contains lots of  calcium and magnesium ions. It’s common in areas that rely on groundwater, ike the Midwest and Rocky Mountains. As water moves through dirt  and rock, it dissolves calcium and magnesium, carrying  them into the water supply.

Hard water makes it hard to  do your laundry because soap reacts with those ions and  forms a solid called soap scum. Scum is stubborn to get rid of, as cleaning commercials are constantly reminding me. Because once scum forms, it  sticks to your hands, shower, washing machine, even itself.

If soap molecules get scummy, then they can’t stick to the dirt anymore. So harder water typically means soap is less effective than it is in soft water. Despite these problems, washing machines were still a huge time saver.

And cleaning companies saw  big dollar signs ahead if their scientists could find some  consumer-friendly solutions. One company, Proctor and Gamble,  was perfect for tackling this new soap problem, because they were  already a giant in the soap industry. One of P&G’s founders, James Gamble, even got his start as a soap maker.

They were based in Cincinnati, a city nicknamed “Porkopolis” for, you guessed  it, its booming pork industry. Like centuries of craftspeople  before them, P&G used animal fats, byproducts of the meat industry, to make soap. When P&G researchers turned their attention to laundry, they switched to  using synthetic detergents rather than soaps made from animal products.

Soaps and detergents clean dirt in similar ways, and all soaps are detergents,  but not all detergents are soaps. A lot of people use the terms  interchangeably, regardless. But because they’re designer chemicals, synthetic detergents are usually  really great at their jobs.

The scientists also found  that adding certain builder chemicals made the detergents more effective. Builders help by reacting with the calcium and magnesium ions in hard water. They lock those ions away, leaving the rest of the detergent free to do its job.

Builders also make it easier for the  soap-y molecules to get deep into your clothes fibers and stick to  the stubborn dirt embedded there. With builder in the detergent mix, machine-washed clothes got just as clean as hand-washed clothes! Clean, as in the dirt molecules got scooped up.

But when the hard water minerals  reacted with the builder, it left a bunch of tiny solids that didn’t  rinse away with the soap blobs. Meaning clothes came out of the  machine all stiff and crunchy. Not ideal for your comfy couch sweatpants.

So P&G chemists spent nearly  a decade trying to figure out how to get machine-washed  clothes both clean and soft. Cutting down on the amount of  builder helped a bit, but not enough. Until one day, a scientist tried flipping the ratio of builder to cleaning agent.

Like, using way more builder than you would ever need to lock up the hard water ions. For whatever reason, that did the trick. No one could figure out why it worked so well, but clothes were coming out  of the wash clean and soft.

In the end, P&G chemists landed on a formula that used three times as much  builder as cleaning agent. The best builder they found  was sodium tripolyphosphate, and the cleaning agents they settled on were branched alkylbenzene sulfonates. We’ll come back to those.

This formula ultimately became the first fully synthetic laundry detergent: Tide. Within a few years, Tide and other synthetic detergents had found their foothold: consumers were buying a billion  pounds of the stuff every year. It wasn’t just because it kept  people’s clothes clean and soft.

Part of Tide’s success came from an innovative new advertising strategy. P&G bought airtime on radio and TV. Not just for ad spots, but for  entire entertainment programs written specifically for their  target audience: housewives.

I know, I know, it was the 1950s, after all. Sandwiched between those programs  were detergent commercials. And these long-running serials  came to be known as “soap operas.” But for all the time these new  detergents saved on household chores, people soon started noticing a little problem.

The detergent bubbles were just too dang bubbly. Now, people wanted the bubbles.  They liked seeing the bubbles. The bubbles convinced  consumers that their soaps were working when they did the  dishes or cleaned their clothes.

You might even feel this way when you wash your pans or shampoo your hair! Bubbles form from soapy  water because the surfactant in detergent pushes its way  between water molecules. The hydrophilic ends of the  molecule stick to the water, while the hydrophobic ends line up on the air-facing sides of the bubble.

It’s like the opposite of those dirt blobs, and the result is a wafer thin layer of water suspended between two layers of soap. But tons of bubbles are actually a sign of excess soap molecules that aren’t sticking to dirt— if your detergent is doing  its job, extra lather doesn’t mean a better clean, it  just means wasted detergent. Regardless, P&G leveraged their  audience’s desire for suds, bragging that Tide produced “oceans of suds.” And oh boy, did it make suds.

But those suds had to go somewhere. And all that detergent-filled water  was going straight down the drain. Household water waste is usually shuttled through a sewage treatment plant, and one of the water treatment steps involves using bacteria to break down pollutants.

But unlike regular soaps, which were traditionally made from natural fat sources, synthetic detergents were made with designer surfactant chemicals that  microbes couldn’t easily digest. So the detergent molecules never broke down, resulting in obscenely  persistent “oceans of suds”. Up until the 1960s, the most  common cleaning agents in detergent were those branched alkylbenzene  sulfonates we mentioned before.

That’s a lot of syllables, but the problematic part of these molecules is that they’re branched. The branching makes it hard for the bacteria’s enzymes to get in there and digest the molecule. So the surfactants survive  the water treatment process, and are free to keep making  havoc-wreaking bubbles.

Don’t laugh at the bubbles!  This was really really serious! Those bubbles coalesced into giant mats and blobs, clogging rivers and lakes. Some of those blobs were so big that people mistook them for icebergs.

It got so bad that bubbles even made their way into household water taps. In the 1960s, some people were doing their dishes with water straight from the  faucet, no extra soap needed. Which saves a couple seconds on chores, I guess, but is also terrible for, you know, drinking.

Eventually, researchers came  up with a new detergent formula that bacteria could break down. AKA biodegradable. They replaced the branched  surfactants with linear molecules that weren’t so hard for bacteria to chow down on.

And the linear surfactants are the ones that are still used in detergents today. The new formula still made a bunch of bubbles, which kept consumers happy. But water treatment microbes could finally break down the detergent molecules.

Bye bye, bubble bergs! So the water problems ended there, and we all lived happily ever after…right? Wrong.

Because the surfactant wasn’t the only detergent ingredient that was ending up in waterways. Remember sodium tripolyphosphate? The builder that made up three  quarters of P&G’s detergent formula?

Well, it turns out that dumping  a bunch of that in the waterways was triggering another disaster  entirely: massive blooms of algae. Every living thing needs phosphorus. You might remember a little thing  called adenosine triphosphate, or ATP, from biology class.

It stores and transfers energy in all our cells and powers our bodies. Yeah, that thing. Well, turns out algae thrive  with easy access to phosphorus.

Like the phosphorus in sodium tripolyphosphate. Thanks to warm water and an  all-you-can-eat nutritional buffet, algae populations began to bloom out of control. It filled lakes and rivers  with slimy green sludge.

And the blooms weren’t just a cosmetic nightmare. When the algae died and sank to  the bottom of a lake or river, their corpses became fuel for bacteria. As they decompose stuff, bacteria consume oxygen.

And when they started eating all that algae, the bacteria used so much oxygen  that it created oxygen-depleted “dead zones” that choked out  other aquatic wildlife, like fish. This was particularly bad in Lake Erie. In the 1960s, some people  declared the lake completely dead because the oxygen-deprived  dead zones were so extensive.

If you have an older edition  of The Lorax by Dr. Seuss, you might find a reference to Lake Erie there. It was rhymed with “smeary.” Not great press for Cleveland.

And here’s what really gets my goat: By the time everyone started  worrying about the algae blooms, phosphorus wasn’t even that  useful in detergent anymore… Its job was, basically, to be a water softener. But by the late 60s, a lot of American households no longer had hard water. So for many consumers, that overabundance of sodium tripolyphosphate  wasn’t actually doing much.

Besides feeding algae. And there were other, phosphate-free chemicals  that could do the same job. Still, many detergent manufacturers, including P&G, pushed back against  efforts to curb their pollution.

They insisted they weren’t the only ones responsible for polluting the waterways. Technically, that was true. Human waste in sewage was also a major source of fuel for these algae blooms.

But the bubbles certainly weren’t lying! While some businesses fought  against phosphate bans, others leaned into the environmental angle. Purex, one of Tide’s competitors,  ran an ad in 1970 that called out the harmful effects  phosphates had on the environment.

And Purex didn’t come to play. They named names and listed the amounts of phosphates in each of their competitors’ products. That marketing tactic, combined  with community activism and the first Earth Day celebration  in 1970, led to a growing list of city- and statewide bans  on phosphate detergents.

Phosphates were eventually  removed from detergent entirely. And the Clean Water Act of 1972 also came around to help curb pollution and regulate water quality. With these new protections, waterways across the US began to improve.

And thankfully, Lake Erie wasn’t dead after all! As the amount of phosphorus in the water declined, Lake Erie bounced back in the 80s. Dr.

Seuss even removed the line about Lake Erie from updated editions of The Lorax. For a while, it did seem  like the phosphate problems were solved and we’d all live happily ever after. Unfortunately, phosphorus—and algae blooms— are once again choking lakes and rivers.

And this time, the sources are harder to pin down. Among other sources of pollution, agricultural runoff is dumping  phosphorus into our waterways in the form of chemical  fertilizer and animal manure. It’s harder to control this time because it’s not necessarily coming from one place.

And runoff, in particular, isn’t something you can just stick a fence around. The lakes themselves have changed, too. For example, invasive zebra  mussels are actually making modern algae blooms even more harmful  than they were in the ‘70s.

But with the power of organized action, we’ve successfully cleaned up our waters before. And we can do it again. We just need to roll up the sleeves of our freshly washed shirts and make it happen.

By the way, this story was inspired by the incredible book The Devil's Element by Dan Egan. So if you liked this video, you  should absolutely check out the book for other fascinating stories  about the element phosphorus. [♪OUTRO]