drinking water pic

The EPA Knows What’s In Your Water, But Do You?

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It’s no secret that there are elements of our drinking water that most would rather not come to terms with.

Agricultural runoff, natural disasters, and corporate negligence have all contributed to the degradation of our water supplies — just ask the people of Ohio. But what exactly is in our water? Furthermore, what is allowed? One might be surprised.

EPA Regulations

Fortunately for the thirsty, there exists a set of federal regulations called the Safe Drinking Water Act (SDWA) which outlines a national water standard.

Its main function is to combat contaminants, both natural and man-made, that may enter our drinking water, and protect us from crises not dissimilar to an ongoing algae contamination in Ohio.

Though this federal bill has existed since 1974, the water sources from which our drinking water is derived were not actually protected until its amendment in 1996. Now, according to the EPA, our drinking water is scrutinized “from source to tap.”

What kind of contaminants are we talking here?

Unbeknownst to most, sources of our drinking water (lakes, reservoirs, aqueducts) face a proverbial laundry-list of potentially harmful contaminants every day. From factory chemicals, to agricultural runoff, to risky injection wells that are bored deep into rock layers and then filled with hazardous waste.

Though the contaminants vary from source to source, some common undesirables include: Phosphorous, copper, uranium, arsenic, mercury, and even Hexachlorocyclopentadiene—a precursor to pesticide and winner of the terrifyingly long name award.

What should I do? Stop drinking water? Run for the hills?!

Doom and gloom aside, most of these contaminants, though unnerving to say the least, have been deemed relatively inert by the EPA—at least if regulated properly. Under the SDWA such pollutants are permissible granted the parts per million are below a specified level. For example some maximum contaminant levels are as follows:

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 Mg/L = Milligrams per liter

ug/L = Microgram per liter


Arsenic – 0.01 Mg/L

Fluoride – 4 Mg/L

Cyanide (Yes Cyanide) – 0.2 Mg/L

Uranium – 30 ug/L


On the surface 0.2 milligrams of Cyanide for every liter of water you drink may seem terrifying, but in reality it’s actually 1/1000th of the amount considered to be a lethal dose.

You can pick up your glass of water again, it’s (probably) okay. If you feel so compelled, you might even want to check this handy EPA guide to your local drinking water information.

Unregulated chemicals and contamination prevention

Currently the SDWA is monitoring and regulating almost 100 different organic and inorganic chemicals, microorganisms, radionuclides, disinfection byproducts, and overall pollutants.

As new chemicals are introduced to the environment, however, the EPA must continue to both identify and analyze such compounds, and more importantly their possible health effects on those who may consume them.

Currently the EPA studies 30 chemicals per every five years under its Unregulated Contaminant Monitoring program—sorry H2O enthusiasts, you’ll have to wait another two years for the next report to drop.


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James Pero