Where Does Your Water Come From?
Whether you take a shower every day, brush your teeth twice a day (like you’re supposed to), or flush your toilet more than a few times per day (we’re not judging), we’re all, very likely, unfamiliar with where all that water comes from.
In our last post, we started with where your water goes after it goes down your drain and how municipal wastewater treatment works. Now we are going to talk about where your water comes from, because where it comes from is directly tied to what you last poured down your drain.
Where does the water coming out of your sink come from?
Faucet water originates either as ground water (aquifers) or surface water (lakes and rivers). Water from one or both of these sources is then pumped into water treatment facilities, disinfected (to protect you from waterborne diseases), and filtered. After the final filtration process, the water is then officially potable (safe for drinking). Then the potable water is pumped into water tanks, either up high in surrounding hills, or into water towers, if the service terrain is flat. Both of these structures provide the high-pressure that water distribution pipes need to feed the water into homes and businesses; ultimately becoming available in kitchen sinks, bathrooms, and washing machines.
Here is a diagram of a typical potable water processing facility:
Is all potable treatment the same?
Potable water treatment processes vary somewhat from plant to plant but are generally similar across cities. The main differences are based on whether the intake water source is surface water or groundwater; since surface water contains microorganisms which need to be killed with chlorine to prevent diseases.
How much do water filters (i.e. Brita, Berkey, etc) really filter out?
Brita and Brita-type filters typically remove:
1. Metals like mercury, copper, zinc and lead.
2. Organic compounds that affect the color, smell and taste of water.
3. And chemicals like herbicides, pesticides and chlorine.
However, the activated carbon filters aren’t very good at removing trace amounts of bacteria, fluoride, nitrates, and viruses. They also don’t do a good job of removing per-and polyfluoroalkyl substances (PFAS) which are dangerous, persistent chemicals that don't break down. These “forever chemicals” are used in things like cookware, flame retardants, and household cleaning products. One in particular, found in shampoos and cleaners, is 1,4-Dioxane, a clear liquid compound that disappears in water. It’s irritating to the skin, eyes, and respiratory system, and is a possible cause of not only cancer, but damage to the liver and kidneys.
Microplastics are another hazard in drinking water that is becoming problematic to remove. Some research has found that a person drinking the recommended amount of water per day is ingesting 5,100 pieces of plastic from their tap water per year.
So where does this leave us?
The removal of PFAS, 1,4-dioxane, microplastics, and emerging chemicals from potable water are complex and problematic issues. Certain chemicals and contaminants are more difficult to filter out due to the variety of categories - and a number of new emerging contaminants each year are starting to require regulatory action. The ability to remove the full range of contaminants and emerging chemicals are primarily dependent upon the engineering and design feasibility of each water treatment plant, and the “cost-health benefit” of upgrading technology and protocols to address new contaminants.
Ultimately, what needs to be considered here is what we pour down our drains and the understanding that what goes down does not magically disappear but in many ways has a plausible chance of coming back up.
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