In certain parts of the country, you can get a therapeutic dose of oxycontin by drinking a couple of liters of water, according to a recent study. This is not a good thing.

According to Herbert T. Buxton, coordinator of US Geological Survey Toxic Substance Hydrology Program, that agency’s National Survey of Susceptible Streams and Aquifers measured a network of 139 streams in 30 states and found antibiotics, prescription drugs, detergent, DEET, caffeine, and fluoxethene.

The drugs found include hormones, both synthetic and natural, antibiotics, antidepressants, and growth promotors.

No one is sure how this contamination might be affecting our health; one thing we do know is that environmental exposure can affect antibiotic resistance, a growing risk to human health.

In addition, a number of these chemicals are endocrine disruptors, which means they mimic the effect of hormones in our bodies. Studies have demonstrated that endocrine disruptors cause feminization of male fish, and masculinization of female fish.

Buxton explains that these chemicals ended up in the water via a number of pathways. Human sources include wastewater treatment (anything washed down the sink or shower drain or flushed), land application of remaining biosolids following water treatment, septic systems, landfills, industrial discharge and water re-use. Animal pathways include agriculture lagoons, animal feeding operations, land application, processing and aquaculture.

Humans produce about 1.5 kilograms per day of what Buxton politely referred to as manure. Beef cows produce 23 or more kg/day, dairy cows 22 to 68, swine 4 to 11, and chickens 0.09.

Our modern society uses thousands of pharmaceuticals and many more chemical-containing personal care products on a daily basis. The federal Toxic Substances Control Act inventory includes more than 83,000 chemicals. A study at the University of York in the United Kingdom warned that substances in pharmaceuticals or personal care products, which they gave the catchy acronym PPCPs, have been detected in the natural environment around the world.

And while a nascent “green chemistry” movement considers the potential effects a chemical might have out in the environment during the development of that chemical, the vast majority of commercial development of chemicals takes into account only how and whether the chemical does the job for which it is intended.

Given the presence of these chemicals in streams it’s conceivable that our public water supplies could also be contaminated with many of the same chemicals.

Our water is regularly tested, of course, but levels previously considered safe may also be misleading given the increasing potency of some chemicals. “We’re now making pesticides that are more potent and applied in lower concentrations, which means we need to be testing our water for lower concentrations of those chemicals,” Buxton says.

The standard “safe” levels for many chemicals doesn’t take into account interactions these chemicals can have with each other and others in the water, he adds. Chemicals present in concentrations less than one sugar cube in an Olympic-sized swimming pool (which equates to parts per billion) can be bio-active, meaning they affect the function of organisms. Contaminants with a similar mode of action can have an additive or synergistic effect.

Assessing water safety also must consider byproducts created from the environmental degradation and metabolism of these chemicals. Other studies have found some of these contaminants in plants such as carrots and lettuce, and in animal tissue. It’s likely these organisms are taking up chemicals from water sources.

At any rate, Buxton says, water treatment plants are not designed to remove the kinds of trace level organics we’re talking about here.

If all this has you thinking, “darn, I’ll stick with bottled water,” think again. Many bottled waters come from municipal water supplies or other water likely affected by these contaminants. Bottlers may filter or otherwise further treat this water, but those processes aren’t likely to remove these chemicals either. And bottled water is actually subject to less regulation and testing than municipal water supplies, aka tap water. Then there is the very real and growing issue of all those plastic bottles ending up in our oceans.

Using a home filter for your tap water can be a good option, depending on the method.

One way we can all help solve the problem is by reducing contamination at the source. Follow instructions for use and disposal of any chemicals. Take advantage of Austin’s hazardous waste disposal program, and never put things such as unused garden chemicals, oil or fuel in the trash or down the drain. Dispose of unused drugs in the trash, not by flushing them or pouring them down the drain.

Even better, take fewer medications, and only the necessary amount, (some drugs pass through our systems and enter wastewater, er, post-use). Reduce use of detergents and other chemicals, and use natural substances whenever possible. We can all help ensure that the water we drink is mostly just H20.