Just because your tap water is crystal clear with no odd tastes or smells, it doesn’t mean that it really is clean or pure. Far from it, unfortunately. You should not become too complacent about your water simply because you know that it’s treated and regulated. That simple glass of water is probably holding a laundry list of chemical residues and even possible toxins.
Possible Contaminants
Of course, everyone’s water is going to be a little different and these are just some generalities that have been uncovered through numerous water quality studies around the country.
It is too cumbersome to try and list all of the 400+ potential contaminants that you may have in your drinking water, and many do not have recognizable common names that you would understand anyway (such as 1,2,4-Trimethylbenzene or p-Isopropyltoluene). But to stick with some common terms, here is a short sample of what your water might hold:
- Synthetic fertilizers
- Pesticides and herbicides
- Heavy metals (lead, arsenic, mercury, copper)
- Organic solvents (benzene, toluene)
- PCBs
- Diesel, gasoline and other petroleum-based fuels
- Detergents, cleansers and degreasing chemicals
- Livestock waste
- Human waste
- Prescription drug residues
- Bacteria, parasites and viruses
You need to be aware that this list of chemicals does not represent some vague possibility in the event of water treatment failure. These are found in normal drinking water with properly functioning processing and treatment. According to the Environmental Working Group (EWG), 46 states in America have water supplies contaminated by some mixture of these toxins.
Levels for many are monitored and should be at “safe” quantities in your water, but some of the chemicals are new to water supplies and have yet to have safe maximum levels established. In fact, there are some that are not regulated at all. The EWG reports that 2/3 of the chemicals that come from agricultural sources are not regulated at all, and more than half of the toxins that come from other industrial sources are also not monitored. That adds up to a lot of things in your water that nobody is even taking notice off.
Allowable Levels
Of the chemicals that are regulated, there are official maximum levels created by the Environmental Protection Agency (EPA) and these can be enforced for any municipal water treatment facility. Their website has a complete list of all the chemicals under their scrutiny along with their allowable levels. Like the list above, there are too many to properly list here. You can get all the details from the EPA but here are some figures on the more recognizable toxins:
- Benzene – 0.005 mg/L
- Asbestos – 7 million fibers per L
- Mercury – 0.002 mg/L
- Cyanide – 0.2 mg/L
- Barium – 2 mg/L
- Arsenic – 0.010 mg/L
Many of these toxins are only allowed at extremely low levels, usually at or below the levels where it begins to impact human health. While that may be true, there can be future consequences to constant and repeated exposure to even such low levels of these compounds. And don’t forget that many chemicals have no limits at all because the EPA does not (yet) monitor or regulate them. A few examples of unregulated chemicals are lithium, acetone, chlorine dioxide, phosphorus, butane, naphthalene and hydrogen sulfide. Though not as prevalent through the USA as the regulated chemicals, all of these have been found in some water supplies across the country.
Where is it All Coming From?
Such a long diverse list of chemicals logically leads to the next question: how did it all get into the water supply in the first place? Reports on water contamination tend to group the various types of chemicals into the following categories.
- Agricultural run-off
- Industrial run-off
- Urban run-off
- Sewer overflows
- Landfill leaching
- Atmospheric condensates (air pollutants entering the water supply through rainfall)
- Water treatment itself
As you can see, the sources are diverse and represent a large part of both city and rural life. This means that addressing these sources for pollutants is not a simple process. Even the chemical processes that treat your municipal water can create harmful by-products that end up polluting the ground water even further (usually due to the chlorination process).
Run-off is generally the mechanism that brings all these chemicals into our water. Rainfall and drainage moves the material through the soil, where it collects in streams, lakes and underground water reservoirs. It’s not easy to stop.
So, you may want to keep all of this in mind next time you take a drink. This is the reason why water filters and bottled water are becoming so popular these days.
Sources:
http://www.ewg.org/tap-water/sourcesofwaterpollution
http://water.epa.gov/drink/contaminants/
http://www.filterwater.com/t-articles.water-contaminants.aspx
http://www.ewg.org/tapwater/