From Toilet to Tap: Some Dirty Truths About Your Drinking Water

By Jennifer Casey
Published: December 17, 2019
Key Takeaways

We’re all concerned about climate change, air pollution and greenhouse gases, but what do we know about the state of our water supply?

Source: Anette Linnea Rasmussen/

Are you concerned about your water? You should be! Let's discuss why water quality is an issue for everyone, how your choices affect the water supply and what you can do to help.


What are some of the contaminants in our water? How do they get there? What can you do about it?

Down the drain

Some contaminants found in water are accumulated naturally during the hydrologic cycle. Minerals such as calcium and magnesium are present in the ground. When the water passes over rocks and bubbles up from springs it comes in contact with these two common minerals. Even though excessive amounts can cause problems in your garden, these two minerals are generally harmless when it comes to drinking and bathing.


Although more sinister substances like arsenic can enter the water supply from natural deposits that erode and enter the water, these contaminants usually come from manufacturing and agriculture. And even then these mostly only come after being washed down the drain along with many other dangerous substances that are used in commercial applications.

Unfortunately, many contaminants wind up in our water supply because of people like you and me.

Cadmium is an ingredient in paint that can have a detrimental effect on our kidneys. And who hasn't rinsed a paintbrush out in the kitchen sink? Unused prescriptions frequently wind up in the toilet, where they not only become part of the water supply but can go on to adversely affect wildlife in streams, lakes and ponds.


Read More: How to Understand a Water Quality Report

In Colorado, researchers found male fish with both male and female sex organs in streams downriver from sewage treatment plants and scientists suspect that estrogen levels in the water are the culprit. Some of the estrogen found in sewage and water is caused by ‘estrogen mimickers’—chemical compounds found in laundry soap and other products—but estrogen is also present because prescription hormones and birth control pills are being consumed and passed into the sewers. Unused prescriptions are also being flushed down the toilet.


Even most household cleaners contain harmful chemical compounds; the surfactants in laundry soap are not usually biodegradable and are harmful to both plants and wildlife.

And where does all this harmful waste go? Straight down the drain.

One of the largest contributors to water pollution is agriculture. From fertilizer and animal feed additives to herbicides and pesticides, these products not only go down the drain but trickle down into the groundwater. Some common agricultural pollutants are pesticides and nitrates—nitrates bond with the hemoglobin in our red blood cells and can cause serious sickness in infants as well as damage to wildlife and plants.

When water runs from the crop and into the ground, it isn't filtered or processed in any way, so all of those agricultural pollutants enter the environment unchecked. Closer to home, most nutrients used in hydroponics aren't organic and every time a hydroponic reservoir is changed the used nutrient water and its harmful pollutants, including nitrites and phosphates, is flushed straight down the drain, and that's not the end of the story.

Then what happens?

Water that goes down the drain flows into sewers (assuming you aren’t on a septic system) where it's collected by your local municipality. Once at the treatment center, the water is mechanically filtered—meaning particulate matter is physically removed from the water and disposed of.

After everything is physically removed, biological organisms such as bacteria need to be neutralized. For decades, chlorine was the go-to chemical to facilitate this neutralization, but more often these days water treatment centers are turning to chloramines, chemicals that are similar to chlorine, but in a more stable form.

Read More: Organic and Hydroponic Food Safety

That doesn't sound so bad...

It doesn't sound too bad at this point, does it? Stuff goes down the drain, gets treated and comes back to us clean—no big deal, right? But here's the thing, remember the fish with both lady and man parts?

You might be wondering how pharmaceutical-laced water is ending up in lakes and streams and here’s where the problem is. When it rains, sewers overflow. The extra runoff flows into lakes, rivers and oceans without being filtered. This means that herbicides, pesticides, industrial chemicals, household products, paint, pharmaceuticals and human waste, which also contains some of these same pharmaceuticals, are all just going straight into the environment to be absorbed by helpless plants and animals alike.

The chlorine and chloramines added to water during treatment protect us from bacteria and disease, but not without cost. You are probably well aware of the damage that chlorine and chloramines can do to your plants and those expensive beneficial biologicals. Chlorine will dissipate eventually, so a pitcher of water left uncovered for a while will no longer taste or smell like chlorine as the molecules break down.

Read More: Choosing Chlorine Chemicals for Water Disinfection

Chloramines, however, are composed of a chlorine molecule bonded to an ammonia molecule—which makes a more stable compound. Although ‘more stable’ sounds like a good thing, what it actually means is that chloramines last much longer in water than chlorine does.

This is troubling because these compounds are hard to get out of your water, usually requiring a specialized filter, such as a KDF, for effective removal. Chloramine's effect on the human body has not been studied extensively, but what few studies there are indicate a relationship to cancer and respiratory problems. Chloramine's efficacy as a disinfectant has been called into question and some believe that plain old chlorine is actually the superior water treatment solution.

Just for something else to worry about, remember the part about your water getting cleaned at water treatment plants? Well, that's not the whole story because check this out—your municipal water treatment facility can't really do a whole lot.

They strain the chunks and they neutralize bacteria with chlorine and chloramines. That's it. All that arsenic? Still in there. Cadmium? Hello, still there. Nitrites, phosphates—heck, even naturally-occurring pollutants like radium and boron are all still present in your water.

And guess what else? Every time water runs through the cycle and more contaminants are added, it all gets more concentrated, so your tap water is getting more and more contaminated every day. Although fresh water from rain and snow runoff can help to mitigate this increasing concentration of harmful chemicals to some degree, some of the chemical pollutants also evaporate into the atmosphere, causing acid rain.

What can I do to help protect the earth's water supply?

Even though there isn't much you can do about things like overflowing sewers, there is a lot you can do to decrease your impact on our water. As a hydroponic gardener, you can utilize organic nutrients whenever possible. As a consumer, you can choose organic, biodegradable cleaners. Many of these cleaners are not only better for our water and the planet, they work as well or better than the traditional kind, are easier on your skin and clothes and smell much better too!

Also, never flush unused prescriptions. Cap the bottle and dispose of it in the garbage. Half an eternity in a landfill just might be long enough for the chemicals to break down completely. Although your dirty paintbrushes, extra-strength detergent and hydro reservoir dumps are part of the problem, they are a mere trickle into the veritable ocean of chemical effluent that is our water.

Agricultural and industrial runoff is the main culprit where water contamination is concerned. A good reverse osmosis filter for your home will protect your body from most of the nasties and garden reverse osmosis is practically a must for hydroponics. Choosing to invest in companies that are environmentally responsible also helps immensely.

On a day-to-day basis, choosing organic foods and fabrics and being a smart consumer will eventually show companies that what they do matters to you. Checking out organizations like 1% for the Planet is an excellent way to get a better look at companies that care about the environment.

Learning how to deal with these contaminants on a municipal level is a step toward solving the problem, but the biggest step we could take would be to find a way to limit the contaminants going into our water in the first place.

  • Is regulation the answer?
  • Should polluting companies be fined?
  • How about the companies that make the billions of gallons of everyday products that are slowly (and not so slowly) poisoning or water and our planet?
  • Can this be allowed to continue until it’s too late?

Answering these questions is beyond the scope of this article and any discussion about them would inevitably lead to a discussion about money and freedom and of course our freedom to make money, which has proven to be the most difficult of American values to legislate against time and time again!

Some countries like Germany and Switzerland already regulate certain chemicals to ensure the safety of their water and I personally hope the United States follows suit. If your government can't regulate what goes down the drain, they can't guarantee what comes out of the tap!

Ultimately the first step toward a solution is awareness. Air pollution, carbon emissions and greenhouse gases are all part of our everyday vernacular now, and constantly hearing about these problems encourages people to think about the issues and sometimes even find ways to help out. Let's start working to bring this sort of awareness to the issue of our water quality as well.

Co-authored by Richard Gellert

Read Next: Is Chemical Flushing Necessary?


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Written by Jennifer Casey

Profile Picture of Jennifer Casey
Jennifer Casey loves her two dogs, her husband, the amazing garden he grows, and living in the country. In that order. Crafting, reading, and cooking food she picks from the garden are her favorite ways to spend her time.

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