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Contaminants in Drinking Water


 How Much is Too Much Poison in Your Water?



James P McMahon



Recent studies by the US Geological Survey and EPA have identified hundreds of chemical contaminants in drinking water. These range from pharmaceuticals, pesticides, and industrial waste to things you may never have thought of such as the cocaine in the Thames River or ingredients from the skin lotion you used this morning. Each of these are present in very small amounts but I'm wondering just how much is too much poison in your water.


When Beluga Whales are found dead in the St. Lawrence Seaway their body fat contains enough contamination to qualify them as hazardous waste. And yet there are no individual sources of highly toxic chemicals affecting them. This contamination cannot be blamed on one or a number of industrial polluters. Rather the effect is due to the fact that the whales absorb minute quantities of toxins that are all being used at allowable levels. It is the sheer number of different chemicals and the size of the watershed feeing the Seaway that creates a 'toxic soup' in which the whales reside.

In another example, scientists at the University of California in Berkeley raised frogs in both treated water and water containing only 1 part per billion of atrazine, a very common pesticide used by farmers. The frogs raised in the atrazine water developed both male and female sex organs. The frogs raised in clean water did not.


Likewise, it's important to understand how EPA determines the allowable level of contaminants in public drinking water systems. The Maximum Contaminant Level is established by EPA and cannot be exceeded by a public water supply system. Unless your water supplier is in violation or has a temporary exemption they must keep the regulated contaminants below the level set by EPA.


Many people think that water with contaminants lower than the MCL is safe. Your public water provider will gladly tell you this if you call and ask. That's where I take exception to the MCL as a standard to strive for. In order to make my point, let's examine the process by which the MCL is determined.

First, a well intentioned team of scientists and staff within EPA analyzes the health affects of a particular contaminant like arsenic. They determine what they think is an allowable level of risk and make a recommendation for a limit to the EPA Administrator.


The Administrator of EPA is appointed by the President. The Administrator may, or may not, find the recommendation of the EPA staff to be 'politically palatable'. If not, they have to raise it. Two other factors accompany the recommended contaminant level. One of these is the cost of implementing the recommendation. When EPA sets a standard every public water supply system in the country must comply. Each city and thus each taxpayer will incur a cost in achieving the new target. The other factor is looked at in terms of health. The number of deaths per thousand individuals or specific rates of disease per thousand are estimated for different MCLs of the contaminant. This is then weighed against the cost of implementation.


Eventually, EPA finalizes the recommendation and the Administrator takes his or her recommendation to the President. The President then makes a recommendation to Congress. Congress then wrestles with the numbers. They weigh additional considerations. Are their constituents feeling environmentally friendly or is money tight due to high gas prices? Is there an election coming up? What it boils down to is an evaluation of health risks or health impacts versus cost.


Take arsenic for example. The EPA staff initially recommended a standard of 3 ppm. The new standard set this past January is 10 ppm. Before that it was 50 ppm. So, was 50 ppm of arsenic safe when you were told that it was? Is 10 ppm safe now? Frankly we don't know.


When a customer calls me to talk about achieving healthy water, I consider the EPA standard but I also consider what I know about the health impacts of that particular contaminant. Take mercury as another example - you don't want any of it in your water. None. That's likely not even possible anymore, but the impacts of mercury on health are huge and the metal is now extremely widespread because of the way it moves around the planet carried by wind currents.


Your water provider will most often tell you that your water meets all EPA standards and is therefore safe and you do not need any treatment system. And I think most of them truly believe this. I don't agree.


It is, in my opinion, unreasonable to assume that a public agency has the ability to deliver contaminant free drinking water to your home. These government systems work on too large a scale. You can, however, take steps to protect your family by treating your water appropriately. In my business, which you can see here, I recommend studying your water quality report and then purchasing the system that removes the contaminants in your water. One size does not fit all when it comes to water treatment. Most if not all water sources are different to begin with and subject to different influences on their way to you.


I think someday we'll look back and discover that allowing these levels of contaminants in water are at the root of much of the cancer and developmental issues among children. Like the beached Beluga whale on the shores of the St. Lawrence Seaway what we think of as relatively minor amounts of contaminants may be having a serious cumulative effect on our tissues and organs. We're increasingly exposed to pesticides, carcinogenic chemicals, and unregulated chemicals about which we know nothing not only in our water but in cosmetics and food.


We rely on production systems that rely on chemicals to deliver huge volumes of disease free water. To be able to accomplish this EPA has to allow contaminants and so they establish allowable levels. For the family that wants healthy water, even these levels should be looked at with suspicion and targeted for removal.





Jim McMahon is an ecologist with over 30 years experience working to develop systems that integrate human needs with the natural environment. He provides water treatment systems to individuals and businesses around the country. You can learn more about him at Sweetwater LLC



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Jim McMahon ecologist

James P McMahon Ecologist

"What's in YOUR Water?"

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